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  • IPEN-DOC 28985

    CASTRO, D.P. ; ANDRADE e SILVA, L.G. . Thermal degradation and spectroscopy analysis of TPS/PBAT blends irradiated by Cobalt-60 source. Brazilian Journal of Radiation Sciences, v. 10, n. 3, p. 1-10, 2022. DOI: 10.15392/bjrs.v10i3.2046

    Abstract: This study aimed to prepare blends of natural polymers of TPS with PBAT by reactive extrusion that were subsequently subjected to the irradiation process and evaluated for their thermal and chemical properties. The blends were incorporated with plasticizers (glycerol, castor oil and surfactant) and submitted to the irradiation process using a Cobalt-60 source at a 25 kGy dose and then characterized by FTIR and DSC. The results obtained in the FTIR analysis, the blends did not undergo chemical changes during the irradiation process and thus, maintained their properties. In the DSC analysis, it was observed that the blends F2 (castor oil) and F3 (castor oil and TWEEN® 80) showed higher values of heat flow for degradation than the samples F0 (glycerol) and F1 (glycerol and TWEEN® 80), probably due to the chemical interaction of castor oil and its constituents. There was no thermal variation in the irradiation process between blends F0 and F1 or F2 and F3. It was concluded that it is feasible to replace castor oil with glycerol in TPS/PBAT blends, and that irradiation using a Cobalt-60 source did not change the properties analyzed and contributed to microbiological protection.

    Palavras-Chave: irradiation; biodegradation; cobalt 60; mixing; polymers

  • IPEN-DOC 27057

    BARBEZAN, A.B. ; CARVALHO, L.R. ; VIEIRA, D.P. ; MACHADO-SANTELLI, G.M.; MARTINS, R. ; VILLAVICENCIO, A.L.C.H. . Evaluation of cytotoxicity through MTS test of 2-ACBs (2-dDCB AND tDCB) after exposure to hepatic cells: studies in vitro. Brazilian Journal of Radiation Sciences, v. 7, n. 3, p. 1-17, 2019. DOI:

    Abstract: Food irradiation has been approved in more than 60 countries for many applications in a wide variety of foods. 2-Alkylcyclobutanones (2-ACBs) are the only known radiolytic products formed when foods containing fatty acids are irradiated. Despite the importance of food irradiation, the toxicological potential of 2-ACBs in irradiated food is still no fully understood. In this study we investigated the cytotoxic effects of irradiated palmitic and stearic fatty acids byproducts, 2-dDCB and 2-tDCB, in hepatic cell lines (HepG2, BRL3A and HTC). The cytotoxic effects of 2-dDCB and 2-tDCB were evaluated at 100, 300 and 500 μM for 24 and 48 hours and the cell viability was measured using the MTS assay. While no toxicity was observed for 2-tDCB in all cells for all tested conditions, 2-dDCB was found to be toxic to BRL3A cells (at 100 μM after 48 hours) and HTC cells (at 24 hours in all tested concentrations). HepG2 cells on the other hand, were found to be resistant to 2-dDCB-induced toxicity. Overall our data shows that the byproduct 2-tDCB is not toxic for hepatic cells while 2-dDCB can be used has a potential marker for food irradiation-induced toxicity.

    Palavras-Chave: carboxylic acids; food processing; irradiation; large intestine; liver cells; radiation doses; radiation effects; toxicity

  • IPEN-DOC 26308

    CARA, ANA C.B. de ; ANA, PATRICIA A. da; DEANA, ALESSANDRO M.; ZEZELL, DENISE M. ; VIEIRA JUNIOR, NILSON D. ; FREITAS, ANDERSON Z. de . Análise quantitativa da desmineralização de esmalte dental humano por meio de Tomografia por Coerência Óptica. Revista Brasileira de Pesquisa e Desenvolvimento, v. 13, n. 2, p. 181-184, 2011.

    Abstract: O diagnóstico de lesões incipientes de cárie possibilita a adoção de tratamentos conservadores, evitando intervenções cirúrgico-restauradoras. Dessa forma, exames capazes de detectar precocemente essas lesões são adequados. A Tomografia por Coerência Óptica (OCT) é uma técnica que fornece informações sobre propriedades ópticas do esmalte dental, que podem sofrer alterações devido ao processo de cárie. Assim, o objetivo do estudo foi avaliar a validade da OCT para detecção de diferentes graus de desmineralização de esmalte dental em lesões simuladas de cárie. Foram utilizadas 42 amostras, obtidas a partir de 11 terceiros molares hígidos, as quais foram separadas em 6 grupos e submetidas a diferentes períodos de ciclagem de pH, para simular cáries em diferentes estágios. Para avaliar as possíveis alterações sofridas por cada amostra, estas foram examinadas pela técnica de OCT antes e depois de cada período de ciclagem para obtenção do coeficiente de atenuação médio de cada uma delas para os momentos analisados. Os resultados foram avaliados usando estatística t-test para amostras pareadas. O coeficiente de atenuação médio foi significantemente diferente antes e depois da desmineralização para os períodos estudados. Assim, a técnica de OCT mostrou-se adequada para avaliar estágios de desmineralização em lesões simuladas de cárie.

    Palavras-Chave: teeth; caries; enamels; demineralization; optical properties; tomography

  • IPEN-DOC 25647

    GOYA, CLAUDIA; SILVEIRA, BRUNO L. da; ARANHA, ANA C.C.; ZEZELL, DENISE M. ; MATSUMOTO, KOUKICHI; EDUARDO, CARLOS de P.. In vitro evaluation of Er:YAG and Nd:YAG laser irradiation on root canal walls: a preliminary study. The Journal of Oral Laser Applications, v. 7, n. 1, p. 45-53, 2007.

    Abstract: Purpose: This study aimed to compare the in vitro effects of Nd:YAG and Er:YAG laser irradiation on root canal walls using scanning electron microscopy (SEM), and evaluate apical leakage and temperature changes in external root surfaces. Materials and Methods: Seventy-four recently extracted human teeth with single, straight roots were used. The teeth were prepared to 1 mm short of the apical foramen by a conventional technique using K-files and assigned to different groups: G1) no laser irradiation/control; G2) Nd:YAG laser/helicoidal technique; G3) Nd:YAG laser/vertical technique; G4) Er:YAG laser/helicoidal technique; G5) Er:YAG laser/vertical technique; G6) Er:YAG and Nd:YAG laser/helicoidal technique; G7) Er:YAG and Nd:YAG laser/vertical technique. The Nd:YAG laser parameters were 100 mJ, 15 Hz, 0.5 J/cm2, and those of the Er:YAG laser were 160 mJ, 10 Hz, 0.9 J/cm2, for four times at 2 mm/s, with 20-s intervals. Temperature changes were recorded thermographically. All teeth were examined by light microscopy or scanning electron microscopy (SEM). Results: No apical leakage was observed in the teeth irradiated with Nd:YAG laser alone or in association with Er:YAG laser. However, in the teeth irradiated with Er:YAG laser, more pronounced leakage was observed. SEM observation showed that Nd:YAG laser irradiation caused melting and crystallization on dentin surfaces. Er:YAG laser samples showed a clean, debris-free surface with opened dentinal tubules. Specimens irradiated by the combination of the two lasers showed a melted layer covering the dentinal tubules. The temperature increase did not exceed 6°C. Conclusions: This study demonstrated that Nd:YAG laser irradiation with or without adjunct Er:YAG laser irradiation is a potentially suitable means of root canal treatment, since morphological alterations are desirable and it did not cause thermal damage to adjacent tissues.

    Palavras-Chave: dentin; lasers; neodymium lasers; thermography; laser radiation; tubules

  • IPEN-DOC 28939

    KANTOVITZ, K.R.; CABRAL, L.L.; CARLOS, N.R.; FREITAS, A.Z. de ; PERUZZO, D.C.; FRANCA, F.M.G.; AMARAL, F.L.B. do; BASTING, R.T.; PUPPIN-RONTANI, R.M.. Impact of resin composite viscosity and fill-technique on internal gap in Class I restorations: an OCT evaluation. Operative Dentistry, v. 46, n. 5, p. 537-546, 2022. DOI: 10.2341/20-144B-L

    Abstract: The aim of this in vitro study was to quantitatively evaluate the internal gap of resin composites of high-and low-viscosity used in single- and incremental-fill techniques in Class I cavities exposed to thermal cycling (TC) using optical coherence tomography (OCT). Cavities of 4-mm depth and 3-mm diameter were prepared in 36 third molars randomly distributed into four groups, according to viscosity of restorative resin-based composite (high or low viscosity, all from 3M Oral Care) and technique application (bulk or incremental fill) used (n=9): RC, high-viscosity, incremental-fill, resin-based composite (Filtek Z350 XT Universal Restorative); BF, high-viscosity, bulk-fill, resin-based composite (Filtek One Bulk Fill); LRC, lowviscosity, incremental-fill, resin-based composite (Filtek Z350 XT Flowable Universal Restorative); and LBF, low-viscosity, bulk-fill, resin-based composite (Filtek Flowable Restorative). Single Bond Universal Adhesive system (3M Oral Care) was used in all the experimental groups. The incremental-fill technique was used for RC and LRC groups (2-mm increments), and a single-layer technique was used for BF and LBF groups, as recommended by the manufacturer. The internal adaptation of the resin at all dentin walls was evaluated before and after TC (5000 cycles between 5°C and 55°C) using OCT images. Five images of each restored tooth were obtained. Images were analyzed using ImageJ software that measured the entire length of the gaps at the dentin–restoration interface. The length of gaps (μm) was analyzed using two-way repeated measures ANOVA and the Tukey tests (α=0.05). There was a significant interaction between material types and TC (p=0.006), and a significant difference among all material types (p<0.0001), before and after TC (p<0.0001). Increased internal gaps at the dentin–restoration interface were noticed after TC for all groups. RC presented the lowest value of internal gap before and after TC, while LBF showed the highest values of internal gap after TC. In conclusion, TC negatively affected the integrity of internal gap, whereas high-viscosity, incremental-fill, resin-based composite presented better performance in terms of internal adaptation than low-viscosity, bulk-fill materials in Class I cavities.

    Palavras-Chave: resins; viscosity; in vitro; dentistry; composite materials

  • IPEN-DOC 28936

    HELLEIS, RODRIGO; MAIA, GUILHERME A.R.; CASTRO, ERYZA G. de; BERBEL, LARISSA O. ; COSTA, ISOLDA ; BANCZEK, EVERSON do P.. Niobium- and titanium-based coating for the protection of carbon steel SAE 1020 against corrosion. Anti-Corrosion Methods and Materials, v. 69, n. 4, p. 426-433, 2022. DOI: 10.1108/ACMM-10-2021-2561

    Abstract: Purpose: The purpose of this paper is to evaluate the protection against corrosion of carbon steel SAE 1020 promoted by a niobium- and titanium-based coating produced from a resin obtained by the Pechini method. Design/methodology/approach: A resin was prepared with ammonium niobium oxalate as niobium precursor and K2TiF6 as titanium precursor. Carbon Steel SAE 1020 plates were dip coated in the resin and calcinated for 1 h at 600 ºC. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to characterize the coating morphologically and structurally. Open circuit potential, electrochemical impedance spectroscopy, anodic potentiodynamic polarization and scanning vibrating electrode technique were used to evaluate the corrosion protection of the coating. Findings: The electrochemical analyses evidence slight protection against corrosion of the coating by itself; however, the needle-like crystal structure obtained may potentially provide a good anchorage site, suggesting the coating could be used as a pretreatment that may present similar application to phosphating processes, generating lower environmental impacts. Originality/value: Due to increasingly restrictive environmental laws, new environmentally friendlier surface treatments must be researched. This paper approaches this matter using a combination of niobium- and titanium-based coating, produced by a cleaner process, the Pechini method.

    Palavras-Chave: niobium; titanium; surface coating; corrosion resistance; carbon steels; electrochemistry

  • IPEN-DOC 28935

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . A preliminary proposal for a hybrid lattice confinement fusion-fission reactor for mobile nuclear power plants. Fusion Science and Technology, v. 78, n. 4, p. 259-274, 2022. DOI: 10.1080/15361055.2021.2000327

    Abstract: Scientists detected 2.45-MeV neutrons and in smaller yields 4- and 5-MeV neutrons in deuterated metals under a 2.9-MeV electron beam. Such discovery could allow the use of deuterated metals at temperatures below their melting point to provide nuclear fusion reactions. Such reactions could provide fast neutrons and energy in the form of heat. This work analyzed the results of some experiments to infer the neutron multiplication rate in such environments. It also considered the possible roles that such phenomena could play in a commercial nuclear power reactor under economic and compactness constraints. It seems the best way to promote nuclear fusion is the irradiation of deuterated metals by fast neutrons. This work presents the concept of a hybrid fusion–fission reactor using fissile or fertile fuel to generate heat and fast neutrons along deuterated metals providing excess neutrons (reactivity boost). Additionally, deuterated metals also may have a role in neutron moderation requiring less volume than other moderators (water or graphite). Such a reactor, given its reactivity boost, may burn radioactive residuals (transmutation) at affordable costs while generating power. Alternatively, this hybrid fusion–fission concept could also breed fissile fuel from fertile isotopes using natural uranium as seed.

    Palavras-Chave: metals; deuteration; cold fusion; hybrid reactors; mobile reactors; fission

  • IPEN-DOC 28934

    SANTOS, SILAS C. dos ; RODRIGUES JUNIOR, ORLANDO ; CAMPOS, LETICIA L. . Evaluation of rare-earth sesquioxides nanoparticles as a bottom-up strategy toward the formation of functional structures. Current Applied Materials, v. 1, n. 1, p. 65-74, 2022. DOI: 10.2174/2666731201666220111102037

    Abstract: Background: The strategy to form functional structures based on powder technology relies on the concept of nanoparticles characteristics. Rare-earth sesquioxides (RE2O3; RE as Y, Tm, Eu) exhibit remarkable properties, and their fields of application include energy, astronomy, environmental, medical, information technology, industry, and materials science. The purpose of this paper is to evaluate the characteristics of RE2O3 nanoparticles as a bottom-up strategy to form functional materials for radiation dosimetry. Methods: The RE2O3 nanoparticles were characterized by the following techniques: XRD, SEM, PCS, FTIR, ICP, EPR, and zeta potential. Results: All RE2O3 samples exhibited cubic C-type structure in accordance with the sesquioxide diagram, chemical composition over 99.9 %, monomodal mean particle size distribution, in which d50 value was inferior to 130 nm. Among all samples, only yttrium oxide exhibited an EPR signal, in which the most intense peak was recorded at 358mT and g 1.9701. Conclusion: Evaluating nanoparticle characteristics is extremely important by considering a bottom-up strategy to form functional materials. The RE2O3 nanoparticles exhibit promising characteristics for application in radiation dosimetry.

    Palavras-Chave: rare earth compounds; ceramics; nanoparticles; oxides; dosimetry; radiation doses; structure functions

  • IPEN-DOC 28933

    BARBOZA, WANESSA das G. ; MILAGRE, MARIANA X. ; DONATUS, UYIME ; MACHADO, CARULINE de S.C.; RAMIREZ, OSCAR M.P.; ARAUJO, JOAO V. de S. ; SILVA, REJANE M.P. da ; COSTA, ISOLDA . Corrosion behaviour of the 2098-T351 Al–Cu–Li alloy after different surface treatments. Corrosion Engineering, Science and Technology, v. 57, n. 3, p. 269-279, 2022. DOI: 10.1080/1478422X.2022.2054915

    Abstract: The effect of different surface treatments on the corrosion resistance of the AA2098 Al–Cu–Li alloy has been investigated. Surface characterization was performed using 3D optical profilometry, energy dispersive X-ray spectroscopy and scanning electron microscopy. The corrosion resistance of the 2098 alloy after the surface treatments was investigated in 0.1 mol L−1 NaCl solution by electrochemical techniques and microscopy. Corrosion results showed that the untreated and the chemically etched surfaces were more active than the mechanically abraded and mechanically polished surfaces owing to differences in the nature of the native oxides formed after the surface treatments. Corrosion rate and mode were also affected by how close the exposed surface was to the mid-thickness region of the AA2098-T351 plate relative to the actual top surface (before polishing). This is associated with the variation in the volume fraction and distribution of the T1 phase as the mid-thickness region of the AA2098-T351 plate is approached.

    Palavras-Chave: aluminium alloys; corrosion resistance; lithium alloys; copper alloys; surface treatments

  • IPEN-DOC 28886

    SANTAELLA, CESAR R.K. ; COTINHO, SAMUEL P. ; CORREA, OLANDIR V. ; PILLIS, MARINA F. . Enhancement of the RE-boronizing process through the use of La, Nd, Sm, and Gd compounds. Journal of Engineering Research, v. 2, n. 14, p. 1-7, 2022. DOI: 10.22533/at.ed.3172142206074

    Abstract: Rare-earth elements have been used in the thermochemical treatment of boronizing to enhance boron diffusion. In order to further investigate the effect of these elements on the process, neodymium-, samarium-, and gadolinium were utilized for the treatment of AISI 1045 samples carried out at the temperature of 1173 K for 4 h. The resulting boride layers formed were characterized through optical microscopy, microhardness test, and X-ray diffraction (XRD). The comparison of the layers showed that the addition of neodymium increased the depth by 48%, with samarium by 54%, and with gadolinium by 76%.

    Palavras-Chave: heat treatments; borides; rare earths; diffusion; boron

  • IPEN-DOC 28885

    ARAUJO, JOAO V. de S. ; SILVA, REJANE M.P. da ; VIVEIROS, BARBARA V. ; MILAGRE, MARIANA X. ; MACHADO, CARULINE de S.C. ; COSTA, ISOLDA . Compreendendo os mecanismos de corrosão de ligas de Al-Cu-Li: uma investigação através de técnicas eletroquímicas globais e locais / On the corrosion mechanisms of Al-Cu-Li alloys: an investigation using global and local electrochemical techniques. Quimica Nova, v. 45, n. 6, p. 680-689, 2022. DOI: 10.21577/0100-4042.20170874

    Abstract: In this study, the corrosion mechanism of an Al-Cu-Li alloy manufactured by two different treatment routes (T3 and T851) was evaluated by immersion and electrochemical tests in solutions containing chloride ions (Cl-). For both alloys, the formation of cavities on the surface was associated with micrometer-sized intermetallics (IM’s), however, in addition to this attack, the alloy submitted to T851 treatment also presented an attack called severe localized corrosion (SLC), caused by the preferential attack to the nanometric T1 (Al2CuLi) phase. The electrochemical concepts involved in these two types of attacks were discussed. During the IM’s corrosive process, whereas the O2 reduction occurred over the IM’s, the Al dissolution is favored around the particle, forming trenching and cavities (with 2 and 6 mm of depth). On the other hand, the mechanism associated with the SLC is related to the formation of a differential aeration cell followed by the evolution of H2, with greater depth of attack penetration (8 and 35 mm). Additionally, by the use of the Scanning Vibrating Electrode Technique (SVET), it was concluded that the higher anodic currents observed for the T851 temper were related to the relation between the anodic area (Aa) and the cathodic area (Ac).

    Palavras-Chave: corrosion; chemical composition; microstructure; aluminium base alloys; lithium alloys; copper alloys; ion-selective electrodes

  • IPEN-DOC 28884

    BATALIOTTI, MURILO D.; COSTA, FRANCINE B.; MINUSSI, FERNANDO B.; ARAUJO, EUDES B.; LIMA, NELSON B. de ; MORAES, JOAO C.S.. Characterization of tellurium dioxide thin films obtained through the Pechini method. Journal of Sol-Gel Science and Technology, v. 103, n. 2, p. 378-385, 2022. DOI: 10.1007/s10971-022-05844-7

    Abstract: Tellurium dioxide (TeO2) thin films were deposited on silicon substrates through the Pechini method, after which they were heat treated at different temperatures. The heat treatment temperatures were defined from the thermogravimetry-differential scanning calorimetry (TG-DSC) data of the precursor gel. The effects of the heat treatment on the structural properties were investigated through X-ray diffraction (XRD), atomic force microscopy, and Raman spectroscopy. The TG-DSC data showed four different weight loss steps due to the reduction of telluric acid to tellurium, the removal of the excess ethylene glycol, the decomposition of citric acid, and the degradation of polyester. The XRD and Raman data showed the presence of the γ- and α-TeO2 phases in the films treated at 400–500 °C. Lattice parameters of the observed crystalline phases were determined by Rietveld refinement, with which it was possible to evaluate the crystallite size and microstrain using the Williamson-Hall method. The heat treatment temperature directly influenced the crystallite size and the surface roughness of the films, which showed similar behaviors with the temperature.

    Palavras-Chave: tellurium oxides; sol-gel process; crystallization; grain refinement; thin films; x-ray diffraction

  • IPEN-DOC 28883

    BARTOLOMEI, SUELLEN S.; SILVA, FELIPE L.F. da; MOURA, ESPERIDIANA A.B. de ; WIEBECK, HELIO. Recycling expanded polystyrene with a biodegradable solvent to manufacture 3D printed prototypes and finishing materials for construction. Journal of Polymers and the Environment, v. 30, n. 9, p. 3701-3717, 2022. DOI: 10.1007/s10924-022-02465-7

    Abstract: The amount of plastic waste generated is causing damage to the environment, such as sea and soil pollution, and one of the alternatives for disposing of polymers is recycling. This work proposes recycling expanded polystyrene using a biodegradable solvent, its plastification with glycerol, and the preparation of the composite with post-consumer recycled gypsum for applications to manufacturing by 3D printing and for finishing materials for construction. Specimen for tensile testing and shore D hardness were prepared by injection process and by 3D printing. In addition, Thermogravimetric (TG), Fourier-transform infrared spectrometry (FTIR), Differential scanning calorimeter, Scanning electron microscope (FESEM) analyses, and flame propagation tests were also carried out. TG and FTIR analyses show that the recycling process did not degrade the material, and the addition of glycerol and gypsum improved the thermal stability of the composite. The mechanical properties of the injected and 3D printed samples with gypsum were similar, due to the dimensional stability of the manufactured filament, which improved the speed and quality of the specimen printing. The increase in ductility and the reduction in the glass transition temperature showed that the recycled expanded polystyrene (RPS) were effectively plasticized with the addition of 2 wt% glycerol, preserving their flame self-extinguishment when subjected to the flame propagation test. Due to these properties, the plasticized RPS can be used to manufacture articles for finishing in civil construction, and the RPS composite can be used to manufacture 3D printed prototypes.

    Palavras-Chave: 3d printing; recycling; composite materials; gypsum; polystyrene

  • IPEN-DOC 28882

    SOUZA, J.P. ; FUJIMOTO, T.G. ; BATISTA, R.M. ; STEIL, M.C.; MUCCILLO, R. ; MUCCILLO, E.N.S. . Phase transformation/stabilization and ionic conductivity in tantalum oxide co‑doped zirconia‑scandia solid electrolyte. Ionics, v. 28, n. 8, p. 3919-3926, 2022. DOI: 10.1007/s11581-022-04604-5

    Abstract: The influence of small amounts of tantalum oxide as co-dopant on phase transformation and stabilization, microstructure and ionic conductivity of zirconia-10 mol% scandia is reported in this work. Cylindrical pellets were prepared by solid state synthesis with sintering at 1500 °C for 5 h. High relative density values (> 95%) were achieved. Reduction of the enthalpy for the cubic ⇌β-rhombohedral phase transformation was found for increasing amounts of the co-dopant. Full stabilization of the cubic structure at room temperature was obtained with only 0.45 mol% tantalum oxide addition. The ionic conductivity of sintered specimens was investigated as a function of the temperature and oxygen partial pressure by impedance spectroscopy. The fully stabilized co-doped system revealed a pure ionic conduction behavior up to 800 °C with wide electrolytic domain. In the 700–800 °C range, the ionic conductivity of co-doped specimens is similar to that of pure zirconia-scandia.

    Palavras-Chave: zirconium; ceramics; phase transformations; microstructure; solid electrolytes; ionic conductivity

  • IPEN-DOC 28880

    LARANJA, MARCIO J.; JUNIOR, FRANCISCO H.S.; NOGUEIRA, GABRIELA A.; VIEIRA, LAIS H.S.; OLIVEIRA, NAIARA C.; SOARES, JOAO M.; CORDEIRO, CARLOS H.N.; OTUBO, LARISSA ; MOREIRA, ALTAIR B.; FERREIRA, ODAIR P.; BISINOTI, MARCIA C.. Valorisation of sugar cane bagasse using hydrothermal carbonisation in the preparation of magnetic carbon nanocomposite in a single-step synthesis applied to chromium adsorption. Journal of Chemical Technology and Biotechnology, v. 97, n. 8, p. 2032-2046, 2022. DOI: 10.1002/jctb.7074

    Abstract: BACKGROUND: Sugar cane bagasse (SB) is a by-product of the sugar cane industry, and is obtained on a large scale. In this paper, SB was used as a source of carbon for preparing a magnetic carbon nanocomposite (MCN-SB) through one-step hydrothermal carbonisation (HTC), in the presence of iron (III) nitrate. By way of comparison, SB was replaced by glucose in HTC (MCN-GLU), and a thermal treatment of this material was then performed under an N2 atmosphere (MCN-GLU-HT). The physical and chemical properties of the nanocomposites were assessed, and the magnetic samples were applied as adsorbents. RESULTS: MCN-SB and MCN-GLU are composed of iron oxide nanoparticles embedded in carbonaceous matrix which also contain oxygenated groups. The MCN-SB sample was already magnetic after HTC, showing a magnetization saturation (Ms) of 5.0 emu g−1, due to the presence of magnetite, whereas MCN-GLU consisted of hematite and required additional thermal treatment (HT) to acquire magnetic properties, with MCN-GLU-HT showing an Ms of 30.5 emu g−1. In turn, the mesoporous structure and higher specific surface area (SSA) of MCN-GLU-HT (SSA 90 m2 g−1) than MCN-SB (SSA 53 m2 g−1) was a causative factor for its higher capacity of hexavalent chromium [Cr (VI)] removal (939 μg g−1), when compared to MCN-SB (768 μg g−1), which has a nonporous structure. CONCLUSION: The results suggest that SB can be reused, by means of HTC, for the preparation of a magnetically recoverable adsorbent, showing good adsorption properties. © 2022 Society of Chemical Industry (SCI).

    Palavras-Chave: sugar cane; bagasse; nanocomposites; biomass; environment; chemical properties

  • IPEN-DOC 28879

    ARAUJO, LEANDRO G. de ; VIEIRA, LUDMILA C. ; CANEVESI, RAFAEL L.S.; SILVA, EDSON A. da; WATANABE, TAMIRES ; FERREIRA, RAFAEL V. de P.; MARUMO, JULIO T. . Biosorption of uranium from aqueous solutions by Azolla sp. and Limnobium laevigatum. Environmental Science and Pollution Research, v. 29, n. 30, p. 45221-45229, 2022. DOI: 10.1007/s11356-022-19128-8

    Abstract: The main goal of this study was to assess alternatives to the current challenges on environmental quality and circular economy. The former is here addressed by the treatment of radioactively contaminated solutions, and the latter by using abundant and low-cost biomass. In this paper, we examine the biosorption of hexavalent uranium (U(VI)) in a batch system using the macrophytes Limnobium laevigatum and Azolla sp. by three operational parameters: biomass dose, metal ion concentration, and contact time. Simulated solutions were firstly addressed with two biomasses, followed by studies with real liquid organic radioactive waste (LORW) with Azolla sp. The batch experiments were carried out by mixing 0.20 g biomass in 10 mL of the prepared solution or LORW. The total contact time employed for the determination of the equilibrium times was 240 min, and the initial U(VI) concentration was 0.63 mmol L−1. The equilibrium times were 15 min for L. laevigatum and 30 min for Azolla sp. respectively. A wide range of initial U(VI) concentrations (0.25–36 mmol L−1) was then used to assess the adsorption capacity of each macrophyte. Isotherm models validated the adsorption performance of the biosorption process. Azolla sp. presented a much higher U(VI) uptake (0.474 mmol g−1) compared to L. laevigatum (0.026 mmol g−1). When in contact with LORW, Azolla sp. removed much less uranium, indicating an adsorption capacity of 0.010 mmol g−1. In conclusion, both biomasses, especially Azolla sp., can be used in the treatment of uranium-contaminated solutions.

    Palavras-Chave: sorption; uranium; aquatic organisms; radioactive waste management

  • IPEN-DOC 28878

    DEL NERO, R.A.; EMILIOZZI, C.Z.S.; SIQUEIRA, P.T.D. ; ANTUNES, P.C.G. ; SERANTE, A.R.. Influence dosimetric study of different couches in radiotherapy treatments. Brazilian Journal of Radiation Sciences, v. 10, n. 2, p. 1-24, 2022. DOI: 10.15392/bjrs.v10i2.2018

    Abstract: Radiotherapy is a recommended procedure for 52% of cancer cases, in average, as one of the treatment forms, therefore, it is important for the clinical practice to investigate the affecting factors in dose distribution received by the patients, such as immobilization devices and treatment couch. With the introduction of treatments with modulated intensity techniques like IMRT and VMAT, the number of incidence fields used for patient treatment increased, making couch’s dosimetric effect more significant in these modalities. The attenuation data acquisition referring to the treatment couches, as well as the TPS data evaluation, show important parameters for the clinical practice because they influence what happens with the dose delivery during the treatment, ensuring a better quality and safety to the treatments. This research presents experimental results evaluating the couch’s impact in the treatments by a study of perturbation in the distribution of surface dose, and dose attenuation according to the gantry’s angle for the couches BrainLABTM, ExactTM and iBEAMTM. Then we propose better density values for the couches BrainLABTM and ExactTM for their inclusion in EclipseTM TPS. Lastly, we compare the dose difference considering the presence or not of couch in the planning. In conclusion, the beam’s attenuation increase by the couches and the doses alterations on the skin must be taken in consideration in the treatment planning process. It is of great relevance that each treatment center perform internal tests to determinate the best density values for available TPS.

    Palavras-Chave: attenuation; density; dosimetry; irradiation procedures; phantoms; planning; radiation dose distributions; radiotherapy; surface area

  • IPEN-DOC 28877

    BURRELLO, S.; CALABRESE, S.; CAPPUZZELLO, F.; CARBONE, D.; CAVALLARO, M.; COLONNA, M.; LAY, J.A.; LENSKE, H.; AGODI, C.; FERREIRA, J.L.; FIRAT, S.; HACISALIHOGLU, A.; LA FAUCI, L.; SPATAFORA, A.; ACOSTA, L.; BELLONE, J.I.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRISCHETTO, G.A.; CALVO, D.; CHAVEZ LOMELI, E.R.; CIRALDO, I.; CUTULI, M.; DELAUNAY, F.; FINOCCHIARO, P.; FISICHELLA, M.; FOTI, A.; IAZZI, F.; LANZALONE, G.; LINARES, R.; LUBIAN, J.; MORALLES, M. ; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PINNA, F.; RUSSO, G.; SGOUROS, O.; SOLAKCI, S.O.; SOUKERAS, V.; SOULIOTIS, G.; TORRESI, D.; TUDISCO, S.; YILDIRIM, A.; ZAGATTO, V.A.B.. Multichannel experimental and theoretical constraints for the 116Cd(20Ne, 20F) 116In charge exchange reaction at 306 MeV. Physical Review C, v. 105, n. 2, p. 024616-1 - 024616-20, 2022. DOI: 10.1103/PhysRevC.105.024616

    Abstract: Background: Charge-exchange (CE) reactions offer a major opportunity to excite nuclear isovector modes, providing important clues about the nuclear interaction in the medium. Moreover, double charge-exchange reactions are proving to be a tempting tool to access nuclear transition matrix elements (NMEs) related to double beta-decay processes. The latter are also of crucial importance to extract neutrino properties from the half-life of the hypothetical neutrinoless double beta decay and to search for physics beyond the standard model. Purpose: Through a multichannel experimental analysis and a consistent theoretical approach of the 116Cd(20Ne, 20F) 116In single charge-exchange (SCE) reaction at 306 MeV, we aim at disentangling from the experimental cross section the contribution of the competing mechanisms associated with second- or higherorder sequential transfer and/or inelastic processes. Methods: We measured excitation energy spectra and absolute cross sections for elastic + inelastic, one-proton transfer and SCE channels by using the MAGNEX large acceptance magnetic spectrometer to detect the ejectiles. For the first two channels, we also extracted the experimental cross-section angular distributions. The experimental data are compared with theoretical predictions obtained by performing two-step distortedwave Born approximation and coupled reaction channel calculations. We employ spectroscopic amplitudes for single-particle transitions derived within a large-scale shell-model approach and different optical potentials for modeling the initial- and the final-state interactions. Results: The present study significantly mitigates the possible model dependence existing in the description of these complex reaction mechanisms thanks to the satisfactory reproduction of several channels at once. In particular, our work demonstrates that the two-step transfer mechanisms produce a non-negligible contribution to the total cross section of the 116Cd(20Ne, 20F) 116In reaction channel, although a relevant fraction is still missing, being ascribable to the direct SCE mechanism, which is not addressed here. Conclusions: Our analysis provides a careful estimation of the sequential transfer processes which are competing with the direct SCE mechanism for the heavy ion reaction under investigation. The study suggests that the direct SCE should play an important role among the mechanisms populating the final channel. Nevertheless, the analysis of the higher-order processes considered here is mandatory to isolate the direct SCE process contribution and approach structure information on the corresponding NME from the reaction cross section. The description of the latter process and the competition between the two mechanisms deserves further investigation.

    Palavras-Chave: charge exchange; nuclear reactions; nuclear matrix; beta decay; cadmium 116

  • IPEN-DOC 28876


    Abstract: Background: Heavy-ion one-nucleon transfer reactions are promising tools to investigate single-particle configurations in nuclear states with and without the excitation of the core degrees of freedom. A careful determination of the spectroscopic amplitudes of these configurations is essential for the accurate study of other direct reactions as well as β decays. In nucleon transfer reactions core excitations, for both target and projectile systems, are best approached via coupled-channels reaction schemes. Despite being notoriously demanding in terms of computing resources, coupled-channels analyses are progressively becoming more affordable even within model spaces large enough for tackling medium mass nuclei. In this context, the 76Se(18O, 17O) 77Se reaction, here under study, gives a quantitative access to the relevant single-particle orbitals and core polarization configurations built on 76Se. This is particularly relevant, since it provides data-driven information to constrain nuclear structure models for 76Se, which is the daughter nucleus in the 76Ge ββ decay. This reaction is one of the systems studied in the frame of the Nuclear Matrix Elements for Neutrinoless double beta decay project. Purpose: We want to analyze transitions to low-lying excited states of the residual and ejectile nuclei in the 76Se(18O, 17O) 77Se one-neutron stripping reaction at 275-MeV incident energy and determine the role of single-particle and core excitation in the description of the measured cross sections. In addition, we explore the sensitivity of the calculated cross section to different nuclear structure models. Methods: The excitation energy spectrum and the differential cross-section angular distributions are measured using the MAGNEX large acceptance magnetic spectrometer for the detection of the ejectiles and the missing mass technique for the reconstruction of the reaction kinematics. The data are compared with calculations based on distorted-wave Born approximation, coupled-channels Born approximation, and coupled reaction channels adopting spectroscopic amplitudes for the projectile and target overlaps derived by large-scale shell-model calculations and interacting boson-fermion model. Results: Peaks in the energy spectra corresponding to groups of unresolved transitions to 77Se and 17O are identified. The experimental cross sections are extracted and compared to theoretical calculations. A remarkable agreement is found, without using any scaling factors, demonstrating that the adopted models for nuclear structure and reaction take into account the relevant aspects of the studied processes. The main transitions which contribute to the cross section of each peak are identified. Conclusions: The coupling with the inelastic channels feeding states in entrance and exit partitions is important in the one-neutron transfer reaction and should be accounted for in future analyses of other direct reactions such as single and double charge exchange processes involving 76Se isotope. The description of 77Se indicates the need of a large model space, in the view of an accurate description of the low-lying states, a feature that should be likely accounted even for ββ-decay studies of 76Ge.

    Palavras-Chave: nuclear matrix; neutron transfer; double beta decay; oxygen 18; selenium 76

  • IPEN-DOC 28875

    DARRIBA, G.N.; MUNOZ, E.L.; RICHARD, D.; AYALA, A.P.; CARBONARI, A.W. ; PETRILLI, H.M.; RENTERIA, M.. Insights into the aftereffects phenomenon in solids based on DFT and time-differential perturbed γ-γ angular correlation studies in 111In (→111Cd)-doped tin oxides. Physical Review B, v. 105, n. 19, p. 195201-1 - 195201-15, 2022. DOI: 10.1103/PhysRevB.105.195201

    Abstract: Recently, a model based on a combined ab initio/time-differential perturbed γ -γ angular correlation (TDPAC) study in the 111In(→ 111Cd)-doped SnO2 semiconductor was proposed to enlighten the origin of the dynamic hyperfine interactions (HFIs) observed in oxides after the electron-capture (EC) decay of the probe nucleus of the 111In parent. It was demonstrated that both the EC as well as the acceptor level introduced by the Cd impurity can contribute to the variation of the electric-field gradient (EFG) at the Cd site (responsible for this phenomenon) due to charge fluctuations of the electronic holes created [Darriba et al., J. Phys. Chem. C 122, 17423 (2018)]. To disentangle both effects, we performed here TDPAC reversible experiments in 111In(→ 111Cd)-doped SnO in the temperature range 20–900 K and a complete electronic structure density functional theory study of the Cd-doped SnO system as a function of the charge state (q) of the impurity. The isovalent 111Cd probe impurity in this isocationic oxide was selected to demonstrate that the acceptor character of the probe is not a necessary condition to observe this electronic phenomenon when the EC is already present. A majority fraction of probes sensed a time-dependent HFI (HFI1) for all temperatures, and the unexpected minority always sensed a static interaction (HFI2). Comparing results from these experiments, the ab initio calculations of the EFG tensor and defect formation energies, HFI1 and HFI2, were assigned to 111Cd probes localized at substitutional Sn sites free of defects [with the valence band (VB) completely filled, q = 0] and with an electronic hole trapped (q = 1+), respectively. In addition, we show that the systems with charge state between these values have very similar formation energies at the top of the VB and different predicted EFGs, giving support from first principles to the existence of random fluctuations between different EFGs, necessary in the construction of the on-off perturbation factor used. We demonstrate that all the probes fill their electronic holes before the TDPAC time window except the outermost one, giving a quantification of the number of electronic holes involved in the production of the dynamic effect, only one in SnO. The probes related to HFI2 reach their stable electronic configuration (q = 1+) before the emission of the first γ ray (γ1) of the γ -γ cascade, while those related to HFI1 fill the last hole after the emission of γ1, producing the dynamic interaction. Enlighted by these results and reviewing TDPAC experiments from the literature using probes with different nuclear decay characteristics, we concluded that, in the absence of EC decay of the probe nucleus of the parent, any probe impurity introducing acceptor or donor states (in semiconductors and insulators) whose ionization changes the EFG should observe a time-dependent HFI provided the lifetime of the nuclear levels that feed the γ1 level and this level itself is shorter than the lifetime of the recovery process (i.e., the lifetime of the electronic holes or the ionized donor electrons).

    Palavras-Chave: angular correlation; time dependence; tin oxides; cadmium 111; electron capture decay

  • IPEN-DOC 28874

    ZUFFI, ARMANDO V.F. ; VIEIRA JUNIOR, NILSON D. ; SAMAD, RICARDO E. . Below-threshold-harmonics-generation limitation due to laser-induced ionization in noble gases. Physical Review A, v. 105, n. 2, p. 023112-1 - 023112-6, 2022. DOI: 10.1103/PhysRevA.105.023112

    Abstract: This work introduces and validates a model that explains an observed upper limitation of the emission of below-threshold harmonics generated by noble gases bound electrons in a restricted region of space. The model uses fundamental parameters from the gases and the laser beam, and correctly predicts an intensity threshold above which the harmonics yield cannot be increased by raising the laser power. This restraint is a consequence from the depletion of electrons due to laser-induced ionization, which exactly compensates the harmonics yield increase with the excitation power.

    Palavras-Chave: rare gases; harmonic generation; ionization; lasers; beams; pulses

  • IPEN-DOC 28873

    TESSARI-ZAMPIERI, M.C. ; SARKIS, J.E.S. ; BARBIERI, C.B.. Metrological aspects of platinum group elements atmospheric deposition in roadside tree leaves: uncertainties and environmental data interpretation. Water, Air, and Soil Pollution, v. 233, n. 3, p. 1-13, 2022. DOI: 10.1007/s11270-022-05549-1

    Abstract: Atmospheric pollution is one of the main concerns in modern society and it poses a direct impact on the environment and public health. Therefore, an enormous number of environmental samples are collected and analyzed around the world on a daily basis. In order to obtain reliable and comparable results, it is paramount to establish a well-defined protocol for environmental sampling and analysis considering the more relevant variations associated with these activities and the processes that affect the distribution of the analytes in the environment. The present case study proposes a protocol to determine the amounts of the platinum group elements (PGEs: palladium, platinum, rhodium) due to atmospheric deposition in Tibouchina granulosa leaves that takes into account the estimation of measurement uncertainties including the sampling component. The samples were collected at a standardized height, in the second node of the branches, with approximately 2 months of environmental exposure. The particulate matter was extracted from the leaf surface by acid leaching using an ultrasonic bath followed by aqua regia digestion. Platinum (Pt), palladium (Pd), and rhodium (Rh) were separated from impurities by cation chromatography and analyzed by ICP-MS. The measurement uncertainties found were in the range of 24 to 33% while the analytical uncertainty lied between 4.5 and 7.3%. The results were expressed regarding metrological aspects, with the expanded uncertainty, within a 95% confidence level, to allow for a more robust interpretation of their relevance in the environmental and regulatory context.

    Palavras-Chave: environment; monitoring; air pollution monitoring; atmospheres; platinum metals; atmospheric precipitations; deposition; trees; biological indicators

  • IPEN-DOC 28872

    SANTOS, M.D.; FUKUMASU, N.K.; TSCHIPTSCHIN, A.P.; LIMA, N.B. ; FIGUEROA, C.A.; WEBER, J.S.; SOUZA, R.M.; MACHADO, I.F.. Effect of Ti/Si and Ti/TiN/Si interlayers on the structure, properties, and tribological behavior of an a-C film deposited onto a C17200 copper-beryllium alloy. Surface and Coatings Technology, v. 441, p. 1-17, 2022. DOI: 10.1016/j.surfcoat.2022.128561

    Abstract: Reduced hardness and wear resistance may limit SAE C17200 copper‐beryllium alloy use in manufacturing applications, such as plunger tips of die casting machines and as cores and inserts for steel dies in injection molding processes. In order to improve the surface properties of Cu—Be alloys, amorphous carbon (a-C) films have been selected since these coatings may show high hardness, low wear rate and low coefficient of friction. However, the adhesion of carbonaceous films on Cu—Be alloys remains a challenge. Two interlayer compositions (Ti/Si and Ti/TiN/Si) were deposited onto Cu—Be disks and silicon wafers to assess amorphous carbon adhesion on substrates made of Cu—Be alloy. The microstructure and topography of the coatings were examined by Field Emission Scanning Electron Microscopy (FESEM) coupled with X-ray dispersive energy spectroscopy (EDS). The chemical composition depth profile was measured by glow discharge optical emission spectroscopy (GDOES), which confirmed distinct coating layers of Ti, Si, a-C (C1 and C2 conditions-pDCMS). A TiN extra layer presence was obtained for the C3 and C4 conditions-pDCMS reactive, confirmed by small angle XRD analysis. Raman scattering spectroscopy showed a higher quantity of sp3 carbon bonds for C3 and C4 coating conditions compared to C1 and C2. Instrumented indentation tests indicated a higher hardness and reduced elastic modulus for C3 and C4 coating systems, corroborating Raman results, in terms of a higher concentration of sp3 bonds. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and coherence correlation interferometry (CCI) were used to characterize the coatings' surface features and scratch tracks after the tests. In addition, ramp load scratch tests were conducted to assess coating adhesion to the Cu—Be alloy substrate by measuring critical loads and the coefficient of friction. The highest critical loads to failure (Lc2) and (Lc3) were found for the Ti/TiN/Si interlayer sample (C4 condition), indicating that this interlayer improved the coating contribution to a gradual increase in the hardness and promotion of an enhanced adhesion strength of the a-C coating.

    Palavras-Chave: beryllium alloys; copper alloys; coatings; adhesion; diamonds; carbon

  • IPEN-DOC 28871

    CASTRO, PEDRO A.A. de ; DIAS, DERLY A. ; DEL-VALLE, MATHEUS ; VELOSO, MARCELO N. ; SOMESSARI, ELIZABETH S.R. ; ZEZELL, DENISE M. . Assessment of bone dose response using ATR-FTIR spectroscopy: a potential method for biodosimetry. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, v. 273, p. 1-7, 2022. DOI: 10.1016/j.saa.2022.120900

    Abstract: The health care application of ionizing radiation has expanded worldwide during the last several decades. While the health impacts of ionizing radiation improved patient care, inaccurate handling of radiation technology is more prone to potential health risks. Therefore, the present study characterizes the bone dose response using bovine femurs from a slaughterhouse. The gamma irradiation was designed into low-doses (0.002, 0.004 and 0.007 kGy) and high-doses (1, 10, 15, 25, 35, 50 and 60 kGy), all samples received independent doses. The combination of FTIR spectroscopy and PLS-DA allows the detection of differences in the control group and the ionizing dose, as well as distinguishing between high and low radiation doses. In this way, our findings contribute to future studies of the dose response to track ionizing radiation effects on biological systems.

    Palavras-Chave: ionizing radiations; radiation doses; dosimetry; skeleton; biological dosemeters; fourier transformation; infrared radiation

  • IPEN-DOC 28870

    SIEBENEICHLER, STEFANIE; OVCHINNIKOV, ALEXANDER; BOSCH-SANTOS, BRIANNA ; CABRERA‑PASCA, GABRIEL A.; FLACAU, ROXANA; HUANG, QINGZHEN; CARBONARI, ARTUR W. ; RYAN, DOMINIC; MUDRING, ANJA‑VERENA. Magnetic phase diagram of the solid solution LaMn2(Ge1−xSix)2 (0≤x≤1) unraveled by powder neutron diffraction. Scientific Reports, v. 12, n. 1, p. 1-16, 2022. DOI: 10.1038/s41598-022-12549-y

    Abstract: The structural and magnetic properties of the ThCr2Si2-type solid solution LaMn2(Ge1−xSix)2 (x = 0.0 to 1.0) have been investigated employing a combination of X-ray diffraction, magnetization and neutron diffraction measurements, which allowed establishing a magnetic composition-temperature phase diagram. Substitution of Ge by Si leads to a compression of the unit cell, which affects the magnetic exchange interactions. In particular, the magnetic structure of LaMn2(Ge1−xSix)2 is strongly affected by the unit cell parameter c, which is related to the distance between adjacent Mn layers. Commensurate antiferromagnetic layers and a canted ferromagnetic structure dominate the Si-rich part of the solid solution, whilst an incommensurate antiferromagnetic flat spiral and a conical magnetic structure are observed in the Si-poor part.

    Palavras-Chave: solid solutions; phase diagrams; crystal structure; neutron diffraction; ferromagnetic materials

  • IPEN-DOC 28869


    Abstract: The new outbreak of coronavirus disease 2019 (COVID-19) has infected and caused the death of millions of people worldwide. Intensive efforts are underway around the world to establish effective treatments. Immunoglobulin from immunized animals or plasma from convalescent patients might constitute a specific treatment to guarantee the neutralization of the virus in the early stages of infection, especially in patients with risk factors and a high probability of progressing to severe disease. Worldwide, a few clinical trials using anti-SARS-CoV-2 immunoglobulins from horses immunized with the entire spike protein or fragments of it in the treatment of patients with COVID-19 are underway. Here, we describe the development of an anti-SARS-CoV-2 equine F(ab′)2 immunoglobulin using a newly developed SARS-CoV-2 viral antigen that was purified and inactivated by radiation. Cell-based and preclinical assays showed that the F(ab′)2 immunoglobulin successfully neutralizes the virus, is safe in animal models, and reduces the severity of the disease in a hamster model of SARS-CoV-2 infection and disease.

    Palavras-Chave: immunoglobulins; coronaviruses; viral diseases; horses; therapy; plasma; antibody formation

  • IPEN-DOC 28868

    GARCIA, RAFAEL H.L. . Por que a palavra "nuclear" causa tanto medo?. Revista Brasileira de Engenharia Química, v. 38, n. 1, p. 14-16, 2022.

    Palavras-Chave: nuclear energy; nuclear power plants; energy sources; biomass; economic impact; public opinion; renewable energy sources

  • IPEN-DOC 28867

    PEREIRA, C.V. ; MAIA, V.A. ; ZAMBIAZI, P.J. ; SOUZA, R.F.B. de ; ANTOLINI, E.; NETO, A.O. . PtSb/C electrocatalysts for glycerol oxidation in alkaline electrolyte. Results in Chemistry, v. 4, p. 1-13, 2022. DOI: 10.1016/j.rechem.2022.100375

    Abstract: Pt/C and PtSb/C catalysts in various atomic ratios were synthesized by the sodium borohydride reducing method and their activity for the glycerol oxidation reaction (GOR) was evaluated in alkaline media. Transmission Electron Microscopy (TEM) images showed that Pt particle size increases with increasing Sb content in the catalyst. X-ray photoelectron spectroscopy (XPS) showed that the ratio of Pt and Sb is close to that expected. By XPS measurements, the presence of Sb2O5 in Pt70Sb30/C and Pt50Sb50/C was observed. X-ray diffraction (XRD) analysis revealed the presence of the face-centered cubic (FCC) structure of Pt and PtSb and of some others phases that could be identified as Sb oxides. By linear sweep voltammetry (LSV) measurements, Pt80Sb20/C showed the highest activity for the GOR in alkaline media for potentials >−0.35 V vs. Ag/AgCl, while Pt50Sb50/C showed the highest GOR activity in the potential range between −0.60 and −0.35 V vs. Ag/AgCl. The direct glycerol fuel cells with Pt80Sb20/C as the anode catalyst showed the best performance. These results attest the beneficial effect of Sb addition to platinum: the activity enhancement in the presence of Sb atoms has to be ascribed to both a bifunctional mechanism related to the presence of Sb oxides, and an electronic effect between platinum and antimony in the PtSb alloy.

    Palavras-Chave: electrocatalysts; fuel cells; glycerol; oxidation

  • IPEN-DOC 28866

    LOPES, FABIO J. da S. ; CARVALHO, SILVANIA A.; CATALANI, FERNANDO; SILVA, JONATAN J. da ; ALMEIDA, ROGERIO M. de; RIBEIRO, FABIO de J.; FELLOWS, CARLOS E.; LANDULFO, EDUARDO ; MENEGATTI, CARLOS R.; PEIXOTO, CARLOS J.T.. First lidar campaign in the industrial sites of Volta Redonda-RJ and Lorena-SP, Brazil. Remote Sensing, v. 14, n. 7, p. 1-21, 2022. DOI: 10.3390/rs14071675

    Abstract: We report on the first aerosol profiling campaign in the Paraíba valley, a hub connecting the region between the two largest Brazilian metropolitan areas, São Paulo and Rio de Janeiro. São Paulo Sanitation Technology Company (CETESB) air quality and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data show homogeneous behavior of the atmosphere throughout the region. A more detailed description of the particulate material in the local atmosphere, including its temporal dependence, can be obtained by using ground-based lidars. Measurements were carried out with a backscatter lidar system in two industrial cities, Volta Redonda and Lorena. The aerosol backscatter profiles present several peaks at different altitudes, indicating the presence of aerosol in several atmospheric layers. In addition, The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) air-mass back-trajectories indicate a possible detection of long-range aerosol transported from biomass burning areas of South America. The present study emphasizes the importance of investigating and monitoring the emission of particulate matter at this important hub connection between two dense populated regions of Brazil.

    Palavras-Chave: optical radar; satellites; aerosol monitoring; atmospheres; industrial wastes; pollution

  • IPEN-DOC 28865

    SANTOS, CALINE O.; SANTOS, BIANCA F.S.; REZENDE, YARA R.R.S.; SILVA, ANDERSON M.B.; CALDAS, LINDA V.E. ; SOUZA, DIVANIZIA N.; SILVA, RONALDO S.; REZENDE, MARCOS V.S.. Thermoluminescence and optically stimulated luminescence of Ba-doped Al2O3 produced by a modified sol-gel route. Radiation Physics and Chemistry, v. 198, p. 1-5, 2022. DOI: 10.1016/j.radphyschem.2022.110194

    Abstract: This work features the synthesis and characterization of Al2O3 phosphors doped with different concentrations of barium. The samples are produced by a modified sol-gel route, with glucose used as a chelating agent. The luminescent response of the phosphors is also evaluated through their thermoluminescence (TL) and optically stimulated luminescence (OSL). These optical properties are characterized with pellets obtained from the addition of Teflon to the phosphors. Through the TL analysis carried out with a heating rate of 10 °C/s, the samples reveal two intense TL glow peaks with different glow curve shapes when varying the dopant concentration of all the samples. By means of the TL emission curves of the pellets, activation energies associated with the transfer processes of the materials are determined. The phosphors present typical exponential OSL decay curves with a predominance of fast and medium components, indicating that the traps have a high photoionization cross section for blue light-emitting diodes.

    Palavras-Chave: dosimetry; thermoluminescence; aluminium oxides; luminescence; optical fibers; stimulated emission

  • IPEN-DOC 28864

    BALOGH, TATIANA S. ; BONTURIM, EVERTON; VIEIRA, LUCAS D.; LUGAO, ADEMAR B. ; KADLUBOWSKI, SLAWOMIR. Synthesis of poly(N-vinyl pyrrolidone) (PVP) nanogels by gamma irradiation using different saturation atmospheres. Radiation Physics and Chemistry, v. 198, p. 1-11, 2022. DOI: 10.1016/j.radphyschem.2022.110238

    Abstract: Nanogels are internally crosslinked particles of nanometric size used in various fields e.g. as such as carriers in drug delivery systems. They can be produced using ionizing radiation in dilute aqueous solutions. This method is carried out in a pure polymer-solvent system, avoiding the addition of any additives such as monomers, surfactants, catalysts and crosslinking agents and no further purification step is necessary. Poly(N-vinyl pyrrolidone) (PVP K-90) nanogels were prepared by gamma irradiation in an aqueous solution. The samples were prepared in triplicate in multipurpose cobalt-60 gamma irradiator using 1, 10, 25 and 100 mM PVP solutions. Samples were irradiated in argon and nitrous oxide conditions with doses from 1 kGy up to 25 kGy with 10 kGy/h dose rate. The mean particle size (Rh) was determined by Dynamic Light Scattering (DLS) and radius of gyration (Rg) and weight-average molecular weight (Mw) by Static Light Scattering (SLS). These samples were morphologically characterized using Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). Samples prepared with 100 mM PVP K-90 solution formed macroscopic gels, in the samples obtained with 25 mM PVP K-90 solution there was a prevalence of intermolecular crosslinking. On the other hand, in the samples generated with 10 mM PVP K-90 solution, there was a predominance of intramolecular crosslinking demonstrated in the tendency to: decrease in the radius of gyration (Rg), in the constancy of the weight-average molecular weight (Mw), in the increase in polymer coil density (ρcoil), in the Rg/Rh ratio (shape factor) around 1.0 indicating homogenous, internally cross-linked spheres, in the high relief spherical structures observed in the AFM images and in the spherical particles with high contrast observed in the TEM images. The saturation of the samples with nitrous oxide doubled formation of hydroxyl radicals, favoring the generation of polymeric radicals. Higher average number of radicals in each macromolecule contributed to the higher number of intramolecular crosslinks.

    Palavras-Chave: nanostructures; gels; argon; nitrous oxide; gamma radiation; pvp; cross-linking; molecular weight

  • IPEN-DOC 28863

    SILVA, ANDERSON M.B.; SOUZA, LUIZA F.; ANTONIO, PATRICIA L. ; JUNOT, DANILO O. ; CALDAS, LINDA V.E. ; SOUZA, DIVANIZIA N.. Effects of manganese and terbium on the dosimetric properties of CaSO4. Radiation Physics and Chemistry, v. 198, p. 1-9, 2022. DOI: 10.1016/j.radphyschem.2022.110207

    Abstract: In this study, a new CaSO4 crystal doped with manganese and terbium is described and its potential for dosimetric applications is evaluated. Crystals were synthesized using the slow evaporation route, and were prepared in pellet form with the addition of Teflon. CaSO4 was doped with manganese and terbium at a concentration of 0.1 mol% in each case. The crystalline structure and optical properties of the crystals were evaluated by X-ray diffraction, Fourier transform infrared spectroscopy and photoluminescence. The suitability of these crystals for thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimetry was also investigated. The material showed adequate OSL and TL characteristics, such as a TL glow curve with two peaks at approximately 205 °C and 325 °C, an adequate OSL decay curve, good reproducibility, and linearity of the luminescent signals, when irradiated with doses of between 200 mGy and 150 Gy. Two trapping centers located at 0.77 and 1.02 eV were revealed. The heating rate dependence was also evaluated. The lowest detectable dose was investigated by the TL and OSL techniques, and the results were presented in mGy for both methods. It was also observed that co-doping with Mn and Tb contributed to a reduction in fading compared to CaSO4:Mn and CaSO4:Tb.

    Palavras-Chave: calcium sulfates; manganese; terbium; optical properties; calcium sulfates

  • IPEN-DOC 28862

    GONCALVES, JOSEMARY A.C. ; MANGIAROTTI, ALESSIO; BUENO, CARMEN C. . Characterization of a thin photodiode as a routine dosimeter for low-dose radiation processing applications. Radiation Physics and Chemistry, v. 198, p. 1-7, 2022. DOI: 10.1016/j.radphyschem.2022.110200

    Abstract: The characterization of a dosimetry system based on a commercial PIN photodiode as a routine dosimeter in a 60Co industrial facility is reported. The main parameters of the dose rate response (repeatability, reproducibility, and angular dependence) and the dose response (dependence on both dose rate and accumulated dose) are investigated. The results obtained, within a dose rate range of 3.7–52.8 Gy/h and doses up to 200 Gy, fully adhere to the standard protocols established for radiation processing dosimetry. The diode performance as a routine dosimeter is validated by the good overall agreement with radiochromic films and alanine dosimetry.

    Palavras-Chave: photodiodes; thin films; gamma radiation; dosimetry; silicon diodes

  • IPEN-DOC 28861

    LIMA, LUCAS N. de; REIS, DANIEL C.; SAKANO, VICTOR K.; FRANCO, MARCO A.; MORAIS, FERNANDO G. ; JOHN, VANDERLEY M.. Influence of microstructure and physical characteristics in the performance of non-professional masks sold in São Paulo. Public Health, v. 205, p. 90-98, 2022. DOI: 10.1016/j.puhe.2022.01.009

    Abstract: Objectives: This study evaluates the performance of eight non-professional face masks sold in São Paulo, Brazil, to prevent aerial transmission of the SARS-CoV-2. Study design: This was a case report with comparative testing. Methods: The masks manufactured with different materials and designs were quantified according to their performance to prevent COVID-19 using two indicators: filtration efficiency (FE) and differential pressure. The fabric grammage and microscopy of the layers were analyzed to understand their influence on the performance indicators. Results: The results show no correlation between grammage in the FE and increasing grammage can compromise breathability indicator. Masks manufactured with cotton widely commercialized during the pandemic have non-uniformized results in FE indicators. Conclusions: There was no evidence between grammage and the number of layers in the FE indicator. The results pointed out that the layer's composition and the microstructure are the best way to evaluate the performance of non-professional masks used to prevent the aerial transmission of the SARS-CoV-2.

    Palavras-Chave: coronaviruses; medical supplies; face; respirators; protective clothing; testing; aerosols; air

  • IPEN-DOC 28860

    JESUS, JULIANA M.S. de; TOMINAGA, FLAVIO K. ; ARGOLO, ALLAN dos S.; NASCIMENTO, ANA C.G. ; BORRELY, SUELI I. ; VIEIRA, DANIEL P. ; BILA, DANIELE M.; TEIXEIRA, ANTONIO C.S.C.. Radiolytic degradation of levonorgestrel and gestodene: performance and bioassays. Process Safety and Environmental Protection, v. 162, p. 520-530, 2022. DOI: 10.1016/j.psep.2022.04.021

    Abstract: This study reports the feasibility of ionizing sources (60Co source and electron beam radiation) to degrade the progestins hormones levonorgestrel (LNG) and gestodene (GES) in synthetic solutions and real pharmaceutical wastewater (RPW). Doses of 0.5–100 kGy and dose rates of 2.5 and 10 kGy h−1 were applied. LNG was shown to be more recalcitrant than GES, with 90% removals achieved at doses around 7.7 kGy (LNG) and 1.6 kGy (GES) in model systems, with LNG showing greater reactivity with reducing species in γ-radiolyis, unlike GES. Furthermore, LNG removal remained around 60% in RPW at low doses, while more than 60% GES removal was observed for all doses. LNG and GES toxicities to Daphnia similis were absorbed dose-dependent, with low doses resulting in toxicity reductions of around 32% (LNG) and 42% (GES); in turn, high doses promoted a fourfold increase in toxicity. γ-radiolysis reduced the cytotoxic character of LNG to NIH-3T3-L1 cells, while non-irradiated or irradiated GES solutions did not exhibit any cytotoxic effect. Finally, the estrogenic activity, evaluated by the YES assay, was dose-dependent for both progestins, which may be related to the evolution of transformation products formed by water radiolysis in each case, decreasing for high doses.

    Palavras-Chave: drugs; hormones; progesterone; waste water; gasers; electron beams; radiolysis

  • IPEN-DOC 28859

    FAROOQ, SAJID ; WALI, FAIZ; ZEZELL, DENISE M. ; ARAUJO, RENATO E. de; RATIVA, DIEGO. Optimizing and quantifying gold nanospheres based on LSPR label-free biosensor for dengue diagnosis. Polymers, v. 14, n. 8, p. 1-12, 2022. DOI: 10.3390/polym14081592

    Abstract: The localized surface plasmon resonance (LSPR) due to light–particle interaction and its dependence on the surrounding medium have been widely manipulated for sensing applications. The sensing efficiency is governed by the refractive index-based sensitivity (ηRIS) and the full width half maximum (FWHM) of the LSPR spectra. Thereby, a sensor with high precision must possess both requisites: an effective ηRIS and a narrow FWHM of plasmon spectrum. Moreover, complex nanostructures are used for molecular sensing applications due to their good ηRIS values but without considering the wide-band nature of the LSPR spectrum, which decreases the detection limit of the plasmonic sensor. In this article, a novel, facile and label-free solution-based LSPR immunosensor was elaborated based upon LSPR features such as extinction spectrum and localized field enhancement. We used a 3D full-wave field analysis to evaluate the optical properties and to optimize the appropriate size of spherical-shaped gold nanoparticles (Au NPs). We found a change in Au NPs’ radius from 5 nm to 50 nm, and an increase in spectral resonance peak depicted as a red-shift from 520 nm to 552 nm. Using this fact, important parameters that can be attributed to the LSPR sensor performance, namely the molecular sensitivity, FWHM, ηRIS, and figure of merit (FoM), were evaluated. Moreover, computational simulations were used to assess the optimized size (radius = 30 nm) of Au NPs with high FoM (2.3) and sharp FWHM (44 nm). On the evaluation of the platform as a label-free molecular sensor, Campbell’s model was performed, indicating an effective peak shift in the adsorption of the dielectric layer around the Au NP surface. For practical realization, we present an LSPR sensor platform for the identification of dengue NS1 antigens. The results present the system’s ability to identify dengue NS1 antigen concentrations with the limit of quantification measured to be 0.07 μg/mL (1.50 nM), evidence that the optimization approach used for the solution-based LSPR sensor provides a new paradigm for engineering immunosensor platforms.

    Palavras-Chave: plasmons; resonance; surfaces; nanostructures; sensors; sensitivity; optimization

  • IPEN-DOC 28858

    JESUS, VIVIANE P. dos S.; VIEIRA, PAULA F.A.; CINTRA, RICARDO C.; SANTANNA, LUCIANA B.; ZEZELL, DENISE M. ; CASTILHO, MAIARA L.; RANIERO LEANDRO. Triple-negative breast cancer treatment in xenograft models by bifunctional nanoprobes combined to photodynamic therapy. Photodiagnosis and Photodynamic Therapy, v. 38, p. 1-9, 2022. DOI: 10.1016/j.pdpdt.2022.102796

    Abstract: Triple-negative breast cancer (TNBC) overexpresses the Epidermal Growth Factor Receptor (EGFR), a characteristic of different types of tumors, linked to worse disease prognosis and risk of recurrence. Conventional treatments are also aggressive and can be morbid.. Therefore, t improvement and development of new methods are notorious. Photodynamic Therapy (PDT) is an effective method for treating different types of cancer by using light radiation to activate a photosensitizing agent (drug) in molecular oxygen presence, promoting cell death., Improving drug uptake in target cells could contribute to PDT efficiency. Accordingly, we developed a bifunctional nanoprobe (BN), used in PDT as a a treatment method in vivo against breast cancer. The BN uses gold nanoparticles with active targeting through the Epidermal Growth Factor (EGF) protein and Chlorine e6 (Ce6) carriers. We evaluated the therapeutic efficacy of in vivo xenograft in 4 groups: Saline, BN, Ce6+PDT, and BN+PDT. As a result, we observed that the BN+PDT group exhibited an excellent effect with greater selectivity to tumor tissue and tissue damage when compared to the Saline, BN, and Ce6+PDT groups. The results indicate a potential impact on breast cancer treatment in vivo.. In conclusion, our data propose that the BN developed heightened PDT efficacy through cellular DNA repair effects and tumor microenvironment.

    Palavras-Chave: neoplasms; mammary glands; nanoparticles; photodynamic therapy; photosensitivity

  • IPEN-DOC 28857

    COLLINA, GABRIELA A. da; CABRAL, FERNANDA V. ; MONTEIRO, CAROLINA M.; MACHADO, GABRIELA B.; GONCALVES, JOSE M.L.A.; FREIRE, FERNANDA; PRATES, RENATO A.; RIBEIRO, MARTHA S. ; PAVANI, CHRISTIANE. The importance of combining methods to assess Candida albicans biofilms following photodynamic inactivation. Photodiagnosis and Photodynamic Therapy, v. 38, p. 1-6, 2022. DOI: 10.1016/j.pdpdt.2022.102769

    Abstract: Background: Methylene blue (MB)-mediated photodynamic inactivation (PDI) has shown good results in killing Candida spp. Although MB solutions are commonly used, new formulations have been designed to improve PDI. However, chemical substances in the formulation may interfere with the PDI outcome. In this sense, different methodologies should be used to evaluate PDI in vitro. Herein, we report different methodologies to evaluate the effects of PDI with an oral formulation (OF) containing 0.005% MB on Candida albicans biofilm. Methods: Biofilms were treated using the MB-OF, with 5 min pre-irradiation time and exposure to a 640 nm LED device (4.7 J/cm2). PDI was evaluated by the XTT reduction test, counting the colony forming units (CFU), a filamentation assay, crystal violet (CV) staining, and scanning electronic microscopy (SEM). Results: PDI was able to reduce around 1.5 log10 CFU/mL, even though no significant differences were noted in metabolic activity in comparison to the control immediately after PDI. A significant decrease in yeast to hyphae transition was observed after PDI, while the biofilm exhibited flattened cells and a reduced number of yeasts in SEM. The CV assay showed increased biomass. Conclusion: MB-OF-mediated PDI was effective in C. albicans biofilms, as it significantly reduced the CFU/mL and the virulence of surviving cells. The CV data were inconclusive, since the OF components interacted with the CV, making the data useless. Taken together, our data suggest that the association of different methods allows complementary responses to assess how PDI mediated by a formulation impacts biofilms.

    Palavras-Chave: antimicrobial agents; methylene blue; chemotherapy; photodynamic therapy

  • IPEN-DOC 28856


    Abstract: The rapidly growing interest in the application of nanoscience in the future design of radiopharmaceuticals and the development of nanosized radiopharmaceuticals in the late 2000′s, resulted in the creation of a Coordinated Research Project (CRP) by the International Atomic Energy Agency (IAEA) in 2014. This CRP entitled ‘Nanosized delivery systems for radiopharmaceuticals’ involved a team of expert scientist from various member states. This team of scientists worked on a number of cutting-edge areas of nanoscience with a focus on developing well-defined, highly effective and site-specific delivery systems of radiopharmaceuticals. Specifically, focus areas of various teams of scientists comprised of the development of nanoparticles (NPs) based on metals, polymers, and gels, and their conjugation/encapsulation or decoration with various tumor avid ligands such as peptides, folates, and small molecule phytochemicals. The research and development efforts also comprised of developing optimum radiolabeling methods of various nano vectors using diagnostic and therapeutic radionuclides including Tc-99m, Ga-68, Lu-177 and Au-198. Concerted efforts of teams of scientists within this CRP has resulted in the development of various protocols and guidelines on delivery systems of nanoradiopharmaceuticals, training of numerous graduate students/post-doctoral fellows and publications in peer reviewed journals while establishing numerous productive scientific networks in various participating member states. Some of the innovative nanoconstructs were chosen for further preclinical applications—all aimed at ultimate clinical translation for treating human cancer patients. This review article summarizes outcomes of this major international scientific endeavor.

    Palavras-Chave: nanoparticles; drug delivery; radiopharmaceuticals; polymers; radioisotopes; theranostics

  • IPEN-DOC 28855

    BORDON, CAMILA D.S.; DIPOLD, JESSICA ; FREITAS, ANDERSON Z. ; WETTER, NIKLAUS U. ; ROSSI, WAGNER de ; KASSAB, LUCIANA R.P.. A new double-line waveguide architecture for photonic applications using fs laser writing in Nd3+ doped GeO2-PbO glasses. Optical Materials, v. 129, p. 1-6, 2022. DOI: 10.1016/j.optmat.2022.112495

    Abstract: A new double-line waveguide architecture produced in Nd3+ doped GeO2-PbO glasses is presented for photonic applications. The waveguides are written directly into Nd3+ doped GeO2-PbO glasses using a Ti:Sapphire femtosecond (fs) laser, operating at 800 nm, delivering 30 fs pulses at 10 kHz repetition rate and writing speed of 0.5 mm/s. Two parallel lines form a dual-waveguide each line being a result of either 4 or 8 superimposed lines. Results of propagation losses, M2 beam quality factor at 632 and 1064 nm, refractive index change, and relative gain at the signal wavelength (1064 nm) are presented. Structural changes, due to laser writing process were investigated by Raman spectroscopy. The observed near-field pattern image showed good waveguiding quality, consisting of a single, circular lobe. X,y-symmetrical guiding for both waveguides was observed. The relative gain reached 4.5 and 6.0 dB/cm for 4 and 8 superimposed lines, respectively, for 420 mW of 808 nm pumping. Propagation losses were 0.89 and 0.44 dB/cm, for 4 and 8 superimposed lines, respectively, leading to positive internal gain of 3.6 and 5.56 dB/cm. The results obtained in the present work demonstrate that this new double line architecture for Nd3+ doped GeO2-PbO glasses is promising for the fabrication of integrated amplifiers, lossless components and lasers.

    Palavras-Chave: germanates; glass; lasers; waveguides; optical properties

  • IPEN-DOC 28854

    GUILHEN, SABINE N. ; WATANABE, TAMIRES ; SILVA, THALITA T. ; ROVANI, SUZIMARA; MARUMO, JULIO T. ; TENORIO, JORGE A.S.; MASEK, ONDREJ; ARAUJO, LEANDRO G. de . Role of point of zero charge in the adsorption of cationic textile dye on standard biochars from aqueous solutions: selection criteria and performance assessment. Recent Progress in Materials, v. 4, n. 2, p. 1-20, 2022. DOI: 10.21926/rpm.2202010

    Abstract: The point of zero charge (PZC) is an inherent electrokinetic property of biochars (BC). It influences the adsorption process under certain pH conditions. Herein, we report the method of determination of the PZC values of ten standard BCs. We used the salt addition method to select the BCs with suitable properties for methylene blue (MB) removal from aqueous solutions. The standard BCs were obtained by pyrolyzing five different biomasses at two distinct temperatures (550°C and 700°C). The BCs derived from rice husk (pHPZC at 7.22 and 7.64 for RH550 and RH700, respectively) and softwood pellets (pHPZC at 6.57 and 6.78 for SWP500 and SWP700, respectively) were selected for their compatibility with cationic dyes such as MB. Results from adsorption experiments indicated the potential use of the RH biochar as an adsorbent for the removal of MB from aqueous solutions. The removal efficiencies were 68.83% and 71.97% for RH550 and RH700, respectively. Considerably low values were obtained for SWP550 and SWP700 (21.61% and 22.84%, respectively). Equilibrium was achieved at 2 h for RH550 and 1 h for RH700, and the adsorption kinetics for the RH BCs could be described by a pseudo-second order equation. The results revealed that even when produced under comparable conditions, BCs obtained from different feedstocks exhibited different cationic dye removing abilities. BCs optimized for the removal of cationic or anionic dyes can be easily engineered by appropriately matching the feedstock with the processing conditions.

    Palavras-Chave: point charge; adsorption; biomass; chars; methylene blue; salts; dyes

  • IPEN-DOC 28853

    SOUZA, A.P.S. ; OLIVEIRA, L.P. de ; GENEZINI, F.A. . Monte Carlo simulations of the S-shaped neutron guides with asymmetric concave and convex surface coatings. Nuclear Instruments and Methods in Physics Research, A, v. 1031, p. 1-14, 2022. DOI: 10.1016/j.nima.2022.166607

    Abstract: During the last decades, neutron beam transportation has been a well-known and established subject of designing proper neutron guides. However, sometimes unusual adaptation or adjustments are required out of original projects and after the operation beginning of facilities. An inter-center transfer of instrument locations also requires a new approach that is not described in detail in the literature. Inside these situations, the use of S-shaped guides has not been fully discussed in the literature. From a geometrical analysis, we have developed a construction formalism of a minimal S-shaped guide by only considering the exclusion of the Line-of-Sight. The guide model has been studied through the wavelength cutoff and the neutron transport efficiency analysis. Here, Monte Carlo simulations using MCSTAS software have been applied. By intending to optimize these guide systems, simulations of this study also consider scenarios that have different supermirrors. A formalism to determine wavelength cutoff for unique and variable index guide systems has also been developed. There is a good correspondence between the theoretical cutoff wavelength values and the corresponding values obtained through Monte Carlo simulations. In addition, we have found specific configurations that combine efficient neutron transport and lower m-values on the convex surfaces of curved guides that form the S-shaped guide.

    Palavras-Chave: monte carlo method; neutron guides; computerized simulation; data processing

  • IPEN-DOC 28852

    MUNHOZ, DANIELLE D.; SILVA, JESSIKA C.A.; FREITAS, NATALIA C.; IWAI, LEO K.; AIRES, KARINA A.; OZAKI, CHRISTIANE Y.; SOUZA, CRISTIANE S.; ROCHA, LETICIA B.; SILVA, MIRIAM A.; HENRIQUE, IZABELLA M.; ELIAS, WALDIR P.; CARVALHO, ENEAS; MORGANTI, LIGIA ; CHURA-CHAMBI, ROSA M. ; PIAZZA, ROXANE M.F.. Recombinant PilS: cloning, expression and biochemical characterization of a Pil-fimbriae subunit. Microorganisms, v. 10, n. 6, p. 1-17, 2022. DOI: 10.3390/microorganisms10061174

    Abstract: Pil-fimbriae is a type IV pili member, which is a remarkably versatile component with a wide variety of functions, including motility, attachment to different surfaces, electrical conductance, DNA acquisition, and secretion of a broad range of structurally distinct protein substrates. Despite the previous functional characterization of Pil, more studies are required to understand the regulation of Pil expression and production, since the exact mechanisms involved in these steps are still unknown. Therefore it is extremely important to have a protein with the correct secondary and tertiary structure that will enable an accurate characterization and a specific antisera generation. For this reason, the aim of this work was to generate potential tools for further investigations to comprehend the mechanisms involved in Pil regulation and its role in pathogenic E. coli infections with the obtaining of a precise native-like recombinant PilS and the corresponding antisera. The pilS gene was successfully cloned into an expression vector, and recombinant PilS (rPilS) was efficiently solubilized and purified by metal affinity chromatography. Protein characterization analyses indicated that rPilS presented native-like secondary and tertiary structures after the refolding process. The generated anti-rPilS sera efficiently recognized recombinant and native proteins from atypical enteropathogenic E. coli strains.

    Palavras-Chave: proteins; protein structure; recombinant dna; biochemistry; cloning

  • IPEN-DOC 28851

    MILAGRE, MARIANA X. ; ARAUJO, JOAO V. de S. ; MACHADO, CARULINE de S.C.; PEREIRA, MARCO S. ; ANTUNES, RENATO A.; GENEZINI, FREDERICO ; COSTA, ISOLDA . Corrosion behavior of the 6061 Al–Mg–Si alloy in different soils extracts. Metallography, Microstructure, and Analysis, v. 11, n. 2, p. 327-340, 2022. DOI: 10.1007/s13632-022-00848-9

    Abstract: In this work, the corrosion behavior of the 6061 Al-alloy in different temper conditions was studied in different soil extracts using electrochemical and surface monitoring techniques. The results showed that the corrosion behavior of the 6061 alloy depends on the soil extract composition, with the highest electrochemical activities related to the soil extracts with the lowest nitrate and sulfate concentrations. The 6061-T6 condition was more susceptible to corrosion than the 6061-HCR one. The results were related to the higher amounts of MgSi particles in the 6061-T6 alloy compared to the 6061-HCR. Sulfate and nitrate ions acted as corrosion inhibitor reducing the corrosion kinetics of the 6061 alloy in solutions with high concentration of chloride ions.

    Palavras-Chave: corrosion; aluminium alloys; soils; corrosion resistance

  • IPEN-DOC 28850

    MADI FILHO, TUFIC ; FERREIRA, ELSON B.; BERRETTA, JOSE R. ; PEREIRA, MARIA da C.C. . Determination of the bromine, manganese and antimony in Nicotiana tabacum solanaceae by using the neutron activation analysis technique. Materials Sciences and Applications, v. 13, n. 2, p. 91-106, 2022. DOI: 10.4236/msa.2022.132007

    Abstract: Tobacco addiction has been mentioned as a leading cause of preventable illnesses and premature disability. Smoking is the main cause of lung cancer and one of the factors that most contribute to the occurrence of heart diseases, among others. The herbaceous species Nicotiana tabacum is a plant of the solanaceae family used for tobacco production. Some authors have conducted research about heavy metals and the toxicity of tobacco. It is, frequently, found in low concentrations in the ground, and superficial and underground waters, even though they do not have environmental anthropogenic contributions. However, with the increase of industrial activities and mining together with the agrochemical use of contaminated organic and inorganic fertilizers, an alteration of the geochemical cycle occurs. As a consequence, the natural flow of these materials increases and is released into the biosphere, where they are often accumulated in the superior layer of the ground, accessible to the roots of the plants. During planting and plant development, fertilizers and insecticides, including organochlorines and organophosphates, are used; consequently, the smoke from cigarette smoking presents various toxic substances, such as bromine (Br), manganese (Mn) and antimony (Sb), elements studied in this work. The procedures for the preparation of the samples were carried out in our laboratories and submitted to irradiation with thermal neutrons at Nuclear and Energy Research Institute (IPEN/CNEN-SP), in the Atomic Energy Institute IEA-R1 research reactor. The irradiated material was, then, analyzed by gamma spectrometry, using a high purity germanium detector (HPGe).

    Palavras-Chave: nicotiana; tobacco; bromine; manganese; antimony; neutron activation analysis

  • IPEN-DOC 28849

    GODOI, CAMILA M. ; SANTOS, MONIQUE C.L. ; NUNES, LIVIA C. ; SILVA, ARACELI J. ; RAMOS, ANDREZZA S. ; SOUZA, RODRIGO F.B. de ; NETO, ALMIR O. . Application of binary PdSb/C as an anode in a polymeric electrolyte reactor-fuel cell type for electrosynthesis of methanol from methane. Materials Research, v. 25, p. 1-8, 2022. DOI: 10.1590/1980-5373-MR-2021-0542

    Abstract: PdSb catalyst prepared in different compositions were applied as an anode in a polymeric electrolyte reactor - fuel cell type (PER-FC) to convert methane into oxygenated products and energy in mild conditions. The PER-FC polarization curves for Pd90Sb10/C presented maximum current density about 0.92 mW cm-2 about 15% higher than PdSb materials. However, the material Pd50Sb50/C showed higher reaction rate for methanol generation than the other materials occurring close to the OCV (r ~ 7 mol L-1 h-1). The qualitative analyses of PER-FC effluent by FT-IR identified products as methanol, carbonate and formate ions from the partial oxidation of methane for all materials.

    Palavras-Chave: antimony; catalysts; cogeneration; current density; electrolytic cells; fourier transformation; fuel cells; methane; methanol; oxidation; palladium

  • IPEN-DOC 28848

    LEON, MORGANE; BEEK, PIETER van; SCHOLTEN, JAN; MOORE, WILLARD S.; SOUHAUT, MARC; OLIVEIRA, JOSELENE de ; JEANDEL, CATHERINE; SEYLER, PATRICK; JOUANNO, JULIEN. Use of 223Ra and 224Ra as chronometers to estimate the residence time of Amazon waters on the Brazilian continental shelf. Limnology and Oceanography, v. 67, n. 4, p. 753-767, 2022. DOI: 10.1002/lno.12010

    Abstract: When rivers mix into the ocean, radium isotopes are released into the dissolved phase allowing us to apply these isotopes as powerful tracers of river plumes spreading into the ocean. We report 223Ra and 224Ra radium activities that were determined in the Amazon River mouth and along the Amazon plume that extends off the coasts of Brazil and French Guyana into the Atlantic Ocean. We summarize 223Ra and 224Ra data from AmasSeds (1991), AMANDES (GEOTRACES process study GApr01; 2007–2008) and M147 (2018) projects, which were conducted in different seasons corresponding to different Amazon discharge rates. We determined the 224Raex/223Ra activity ratios (AR) along the Amazon plume to derive apparent ages and to estimate the residence time of the Amazon waters on the Brazilian continental shelf. Our data suggest that it takes 9–14 d for the Amazon waters to reach the northern continental shelf off French Guyana and 12–21 d to reach the eastern part of the Brazilian continental shelf. These time scales are in good agreement with those derived from a high-resolution numerical simulation of the regional ocean dynamics. We do not find any relationship between the discharge rate of the Amazon River and the residence time of the waters on the Brazilian continental shelf, suggesting that the residence time of the Amazon waters is primarily driven by the ambient northwestward current. Using the apparent ages along the plume, we estimate an average velocity of 26 cm s−1 for the northward transport of the Amazon waters on the continental shelf.

    Palavras-Chave: radium 223; radium 224; rivers; plumes; water pollution; isotopes; amazon river

  • IPEN-DOC 28847

    ORDONEZ-AGUILERA, JUAN F.; LANDMAYER, KARIN; SHIMOKAWA, CARLOS A.K.; LIBERATTI, GIOVANNI A.; FREITAS, ANDERSON Z. de ; TURBINO, MIRIAM L.; HONORIO, HEITOR M.; FRANCISCONI-DOS-RIOS, LUCIANA F.. Role of non-carious cervical lesions multicausality in the behavior of respective restorations. Journal of the Mechanical Behavior of Biomedical Materials, v. 131, p. 1-9, 2022. DOI: 10.1016/j.jmbbm.2022.105232

    Abstract: Objectives: To evaluate biocorrosion and eccentric occlusal loading interplay in marginal quality of cervical restorations. Methods: Cervical wedge-shaped cavities were prepared in extracted premolars and restored with a composite. Premolars underwent either an erosive challenge (E: 1% citric acid/10 min), eccentric occlusal loading (EOL: 150 N/2.5 Hz/106 cycles), E before EOL (E + EOL), E intermediate to EOL (EOL/E/EOL), E after EOL (EOL + E), or no E or EOL (C: control). Marginal quality was analyzed based on a series of Optical Coherence Tomography images. Each of the margins was assigned a gap score (0, 1, 2, or 3) and measurement (μm). For each margin, scores data were analyzed with Kruskall Wallis and Dunn tests, and μm data, with Kruskall Wallis. Overall and for each group, the different margins were compared using Wilcoxon signed-rank test, and the correlation between scores and μm, Spearman’s correlation coefficient (α = 0.05). Results: E and EOL, even if associated, did not influence enamel marginal quality. EOL/E/EOL impaired dentin/ cementum marginal quality only in the case of scores and compared to E. E + EOL, EOL + E or EOL and even C, without differences between each other, did not influence results differently from E or EOL/E/EOL. Margins in dentin/cementum always showed lengthier gaps. Except for C, E and EOL + E cervical margin, there was a strong positive correlation between scores and μm. Conclusions: Eccentric occlusal loading and/or biocorrosion cannot be assumed as causes of marginal failure of cervical restorations in wedge-shaped cavities. A relevant concern may still be the establishment of adhesive interfaces in dentin/cementum. Clinical significance: Although non-carious cervical lesions are strongly being recognized multifactorial and their respective restorations not always behave as expected, biocorrosion and eccentric occlusal loading interplay cannot serve as an explanation for marginal gaps they often present.

    Palavras-Chave: dentistry; caries; teeth; biological recovery; stress corrosion

  • IPEN-DOC 28846

    SUSSA, FABIO V. ; FURLAN, MARCOS R.; VICTORINO, MARCOS; SILVA, PAULO S.C. da . Soil-to-plant transfer factor for stable elements in lemon balm (Melissa officinalis L.) and estimates of the daily intakes. Journal of Radioanalytical and Nuclear Chemistry, v. 331, n. 7, p. 3107-3115, 2022. DOI: 10.1007/s10967-022-08353-7

    Abstract: This study evaluated the transfer factor (TF) of stable elements from soil to Melissa officinalis and the estimated daily intakes for potentially toxic elements. INAA, GFAAS, and ICP-OES techniques were applied to determine the elemental concentration. Br, Ca, Cd, K, Ni, and Rb accumulated the most with the TF (> 1.0), followed by Ba, Co, Cr, Cu, Mg, Mn, Na, Pb, Sb, and Zn (0.1–1.0), while As, Fe, Hf, La, Sc, Sm, Th, Ti, and V had the lowest accumulation (< 0.1). The daily intake (μg day− 1) of As (1.35–10.35), Br (22.5–297), Cd (0.09–0.54), Cr (220–1,270), Cu (31.5–76.5), Ni (0.09–0.54), Pb (4.5–31.5), and Zn (139.5–400.5) even overestimated was still lower than values established by WHO/FAO.

    Palavras-Chave: plants; herbs; agriculture; medicinal plants; ecological concentration; soils; concentration ratio

  • IPEN-DOC 28845

    MORAES, TAMARA S. ; BERGAMASCHI, VANDERLEI S. ; FERREIRA, JOAO C. ; SPINACE, ESTEVAM V. . Preparation and characterization of high-performance Ni-based core-shell catalyst for ethanol steam reforming. Journal of Materials Science, v. 57, n. 9, p. 5384-5395, 2022. DOI: 10.1007/s10853-022-06969-4

    Abstract: A core–shell catalyst, based on nickel nanoparticles supported on silica nanospheres and surrounded by ceria, was tested for ethanol steam reforming (ESR) reaction (H2O/ethanol: 3/1) under low-temperature conditions (400, 500 and 600 °C) in order to test its stability during the reaction. Two other catalysts of Ni supported in SiO2 and CeO2 were also synthesized to be compared with the core–shell catalyst in the ESR. All catalysts showed excellent activity at 500 and 600 °C with 100% ethanol conversion. Increasing the reaction temperature, carbon deposition on the surface of the catalysts decreases throughout the reaction. The core–shell catalyst showed high coke inhibition capacity in the ESR at 600 °C, without coke formation for at least 100 h of reaction. On the other hand, after 20 h of ESR at 600 °C, Ni–SiO2 and Ni/CeO2 catalysts showed formation of 6.3 and 5.2 mgC/(gcat.h) of coke, respectively. The strong redox capacity of ceria together with the change in catalyst structure due to the deposition of cerium oxide on top of Ni particles led to an excellent ESR activity of this catalyst.

    Palavras-Chave: ethanol; cerium oxides; catalysts; nickel nitrates; steam

  • IPEN-DOC 28844

    GASPARIAN, P.B.R. ; MALTHEZ, A.L.M.C.; YOSHIMURA, E.M.; UMISEDO, N.K.; CAMPOS, L.L. . Study of the dosimetric properties of CaSO4:Dy using OSL technique. Journal of Instrumentation, v. 17, n. 4, p. 1-8, 2022. DOI: 10.1088/1748-0221/17/04/P04022

    Abstract: Calcium sulfate doped with dysprosium (CaSO4:Dy) has been used for personal dosimetry using the thermoluminescence (TL) technique for decades and its TL properties are well-known. Considering the advantages of the OSL technique (relatively simple and faster readout and detector reusability) and the potential application of CaSO4:Dy as an OSL detector, this study aimed to investigate the dosimetric properties of CaSO4:Dy using the OSL technique. The present study was carried out using CaSO4:Dy pellets prepared at IPEN irradiated and read in a TL/OSL Risø reader with blue light stimulation and Hoya U-340 filter. OSL dosimetric properties essentially dose response, reproducibility, and fading characteristics were evaluated. Moreover, TL and OSL signals were compared to study the correlation between OSL signals and TL peaks. CaSO4:Dy OSL response is linear from 0.1 to 10 Gy and shows reproducibility better than 5%. The low-temperature TL peak is unstable; however, the OSL signal seems to be associated with higher-temperature peaks.

    Palavras-Chave: dosimetry; radiation doses; radiation monitoring; dysprosium; solid state lasers; thermoluminescence

  • IPEN-DOC 28843

    SOUZA, SUEDEN O.; RAPOSO, BRUNO L.; SARMENTO-NETO, JOSE F.; REBOUCAS, JULIO S.; MACEDO, DANIELLE P.C.; FIGUEIREDO, REGINA C.B.Q.; SANTOS, BEATE S.; FREITAS, ANDERSON Z. ; CABRAL FILHO, PAULO E.; RIBEIRO, MARTHA S. ; FONTES, ADRIANA. Photoinactivation of yeast and biofilm communities of Candida albicans mediated by ZnTnHex-2-PyP4+ porphyrin. Journal of Fungi, v. 8, n. 6, p. 1-14, 2022. DOI: 10.3390/jof8060556

    Abstract: Candida albicans is the main cause of superficial candidiasis. While the antifungals available are defied by biofilm formation and resistance emergence, antimicrobial photodynamic inactivation (aPDI) arises as an alternative antifungal therapy. The tetracationic metalloporphyrin Zn(II) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (ZnTnHex-2-PyP4+) has high photoefficiency and improved cellular interactions. We investigated the ZnTnHex-2-PyP4+ as a photosensitizer (PS) to photoinactivate yeasts and biofilms of C. albicans strains (ATCC 10231 and ATCC 90028) using a blue light-emitting diode. The photoinactivation of yeasts was evaluated by quantifying the colony forming units. The aPDI of ATCC 90028 biofilms was assessed by the MTT assay, propidium iodide (PI) labeling, and scanning electron microscopy. Mammalian cytotoxicity was investigated in Vero cells using MTT assay. The aPDI (4.3 J/cm2) promoted eradication of yeasts at 0.8 and 1.5 µM of PS for ATCC 10231 and ATCC 90028, respectively. At 0.8 µM and same light dose, aPDI-treated biofilms showed intense PI labeling, about 89% decrease in the cell viability, and structural alterations with reduced hyphae. No considerable toxicity was observed in mammalian cells. Our results introduce the ZnTnHex-2-PyP4+ as a promising PS to photoinactivate both yeasts and biofilms of C. albicans, stimulating studies with other Candida species and resistant isolates.

    Palavras-Chave: fungi; yeasts; candida; photodynamic therapy; antimicrobial agents; porphyrins

  • IPEN-DOC 28842

    FERNANDEZ, A.P.R. ; PÉRIGO, E.A. ; FARIA, R.N. . Simulation of galvanostatic charge-discharge curves of carbon-based symmetrical electrochemical supercapacitor with organic electrolyte employing potential dependent capacitance and time domain analytical expressions. Journal of Energy Storage, v. 51, p. 1-9, 2022. DOI: 10.1016/j.est.2022.104471

    Abstract: Electrochemical supercapacitors differ from conventional supercapacitors mainly because they have a very high storage of electrical energy per unit of mass and a capacitance dependent on electrical potential. When studying electrical circuits in the time domain that aim to simulate the curves generated in the charging and discharging processes of electrochemical supercapacitors, as is the case with galvanostatic curves, the capacitance dependent on the electrical potential becomes a factor that considerably increases the degree of difficulty in obtaining the equations for simulating such curves. In this paper, a straightforward electrical circuit was used and fed by a source of electric current I of constant intensity in time in order to simulate the galvanostatic curve properties of a symmetrical supercapacitor evaluated by a galvanostatic cycle technique. Simulation of galvanostatic curves of these carbon-based supercapacitors with organic electrolyte also considered the effects of capacitance dependent on electric potential and the analysis was carried out in the time domain using a 2R(C + kUC(t)) electric circuit powered by a direct current source I. Analytical equations are presented and comparisons between experimental and theoretical curves were made on a quantitative basis.

    Palavras-Chave: capacitors; capacitive energy storage equipment; time dependence; domain structure

  • IPEN-DOC 28833

    DIAZ, JULIO C.C.A. ; VENET, MICHEL; RODRIGUES, ARIANO D.G.; QUIROGA, DAVID A.B.; CORDERO, FRANCESCO; SILVA JUNIOR, PAULO S. da. Ferroic glass behavior in (Bi,Na)TiO3-based lead-free electroceramics. Journal of Alloys and Compounds, v. 918, p. 1-8, 2022. DOI: 10.1016/j.jallcom.2022.165717

    Abstract: Ferroic glass materials, that is, relaxors, spin glasses, and strain glasses attract special attention because of their intriguing physical properties and potential for novel technological applications. Here, several characterization techniques are used to demonstrate the occurrence of simultaneous relaxor and strain glass states in the ternary lead-free xBi0.5Na0.5TiO3-yBi0.5K0.5TiO3-zBaTiO3 (BNBK) system. Hysteresis and current density loops measurements at different temperatures for a BNBK ceramic showed typical characteristics observed in BNT based ceramics containing the tetragonal P4bm phase. Above 400 K, slim loops like those of ferroelectric relaxors are observed. A phase transition with simultaneous relaxor and strain glass character is revealed by the dielectric and anelastic characterizations, which opens up a wide spectrum of possible applications. The minimum of elastic modulus shifts to higher temperatures as the frequency increases, obeying the Vogel-Fulcher relation, which clearly shows the occurrence of a strain glass state in this material. Similar characteristics are observed in the imaginary part of the dielectric permittivity, which demonstrates the relaxor character of this phase transition. The origin of this phenomenon was elucidated with the help of structural characterizations, such as Raman spectroscopy and high-resolution synchrotron X-ray diffraction, at different temperatures. This work provides an in-depth understanding of the structural changes that determine the phenomenology behind the observed ferroic glass behavior and the ferroelectric, dielectric, and mechanical properties of this ternary ceramic composition.

    Palavras-Chave: ferroelectric materials; relaxation; strains; glass; anharmonic oscillators; ceramics

  • IPEN-DOC 28832

    GOMES, J.P.C. ; BANKUTI, R.M.; MORAES, C.A.P.; SEO, E.S.M. . Critical analysis of mosquito repellents formulation in the Brazilian market. International Journal of Development Research, v. 12, n. 4, p. 55129-55131, 2022. DOI: 10.37118/ijdr.24292.04.2022

    Abstract: Mosquitoes are responsible of a wide variety of infectious agents to humans. Malaria, dengue, yellow fever and other diseases transmitted by mosquito bites affect millions of people worldwide causing thousands of deaths each year, causing a major impact on the health services. National programmes to fight vector-born diseases are based on controlling the mosquito population with the use of insecticides in an attempt to interrupt the cycle of these diseases. Unfortunately, insecticide-resistant mosquitoes have already existed in many areas of the world. In Brazil, due to the difficulties in controlling mosquitoes, potential opportunities for intervention arise through innovations that can contribute to minimizing the current problem. We can highlight the use of mosquito repellents as an opportunity. The main aim of this work was to analyze and compare commonly commercialized repellent products in Brazil, designed to repel mosquitos, describing their composition according to ideal parameters for these products reported in scientific literature and also Brazilian legislation.It was a bibliographical review which was carried out using Scielo, Google Scholar and PubMed platforms to look for studies in national and international scientific literature. In addition, Brazilian legislation on the subject was used. The following keywords were used: mosquito, repellents, raw materials, and cosmetics. These keywords were searched for in Portuguese, Spanish and English. Despite the importance of repellents for public health, there is little variety of actives ingredients and formulations. The most important actives ingredients to repeal mosquitos are DEET, Icaridina and IR3535. And the formulations in Brazilian market are lotion, liquid and gel. Even though only a small fraction of the Brazilian population buys repellent products, commercial brands should invest in this sector with effective, safe, not harm the environment and have a good residual products.

    Palavras-Chave: mosquitoes; consumer products; insecticides; health services; public health; insects

  • IPEN-DOC 28831

    MENDES, GABRIEL I.; GIMILIANI, GIOVANA T. ; NOBRE, CAIO R.; TAKADA, HIDESHIGE; FONTES, ROBERTO F.C.; ABESSA, DENIS M. de S.. Can the colors of beach-stranded plastic pellets in beaches provide additional information for the environmental monitoring?: A case study around the Port of Santos, Brazil. International Aquatic Research, v. 14, n. 1, p. 23-40, 2022. DOI: 10.22034/IAR.2022.1943050.1205

    Abstract: Plastic pellets are granules of different polymers used in the manufacture of various plastic products. Plastic pellets can reach the environment due to losses after their manufacturing process, especially the transportation. Loading in harbour areas and transport by ships are the main sources of plastic pellets to the ocean and coastal areas. After pellets reach the environment, they may adsorb and concentrate chemicals contaminants from different sources. Moreover, the weathering of plastic pellets may result in color changes, from white to brownish. This study aimed to analyse the color pattern of pellets collected on beaches of the central coast of São Paulo, Brazil, as an indicator of weathering and ageing processes. Plastic pellets were collected in four sampling surveys conducted between April 2012 and September 2015, and then separated in five color groups: white, yellowish, orange, brown, and pigmented. All sampled beaches had a consistent pattern of light-toned pellets (white and yellowish). This pattern was also found over time, suggesting a constant supply of plastic pellets to the beaches, coming from the harbour area. We also recommend the use of the color pattern of plastic pellets in citizen science monitoring programs.

    Palavras-Chave: microplastics; polymers; pellets; plastics; environmental impacts; water pollution; coastal waters; color

  • IPEN-DOC 28830

    DAMASCENO, SERGIO; TRINDADE, FABIANE J.; FONSECA, FABIO C. ; FLORIO, DANIEL Z. de; FERLAUTO, ANDRE S.. Oxidative coupling of methane in chemical looping design. Fuel Processing Technology, v. 231, p. 1-10, 2022. DOI: 10.1016/j.fuproc.2022.107255

    Abstract: The search for alternative non‑carbon-emitting uses of the huge reserves of natural gas has renewed the interest on direct conversion of methane to value added chemicals. Oxidative coupling of methane (OCM) is a key potential route to convert methane directly to ethylene and innumerous works have focused on the study and development of catalysis for such reaction. Despite these efforts, the limited yield and selectivity achieved still hinders the industrial deployment of such reactions. In this work, we provide a mini-review on studies that focus on OCM process based on the chemical looping (CL) concept, in which methane and oxygen are fed in two separated cyclic steps and a metal oxide catalyst is used as the oxygen source to activate the methane molecule. CL emerges as a promising design for viable methane conversion by improving selectivity due to the use lattice oxygen species for methane activation, avoiding undesired combustion gas phase reactions triggered by molecular oxygen. We review all classes of catalyst tested in this approach, including single oxides, doped and co-doped systems based on Mg-single bondMn oxides, rare earths, Mn-Na2WO4, and perovskites, and most recent optimization of reactor operation conditions.

    Palavras-Chave: alternative fuels; methane; oxidation; catalysts; chemical reaction kinetics

  • IPEN-DOC 28829

    LEITE, GABRIELA R.; BATISTA, DENISE da G.J.; MAZZETI, ANA L.; SILVA, ROSEMEIRE A.; LUGAO, ADEMAR B. ; SOEIRO, MARIA de N.C.. The impact of the CTHRSSVVC peptide upon experimental models of Trypanosoma cruzi infection. Frontiers in Cellular and Infection Microbiology, v. 12, p. 1-8, 2022. DOI: 10.3389/fcimb.2022.882555

    Abstract: Chagas disease (CD), caused by the hemoflagellate protozoan Trypanosoma cruzi, affects more than six million people worldwide and presents an unsatisfactory therapy, based on two nitroderivatives, introduced in clinical medicine for decades. The synthetic peptide, with CTHRSSVVC sequence (PepA), mimics the CD163 and TNF-α tripeptide “RSS” motif and binds to atheromatous plaques in carotid biopsies of human patients, spleen tissues, and a low-density lipoprotein receptor knockout (LDLr−/−) mouse model of atherosclerosis. CD163 receptor is present on monocytes, macrophages, and neutrophils, acting as a regulator of acute-phase processes and modulating aspects of the inflammatory response and the establishment of infections. Due to the potential theranostic role of PepA, our aim was to investigate its effect upon T. cruzi infection in vitro and in vivo. PepA and two other peptides with shuffled sequences were assayed upon different binomials of host cell/parasite, including professional [as peritoneal mouse macrophages (PMM)] and non-professional phagocytes [primary cultures of cardiac cells (CM)], under different protocols. Also, their impact was further addressed in vivo using a mouse model of acute experimental Chagas disease. Our in-vitro findings demonstrate that PepA and PepB (the peptide with random sequence retaining the “RS” sequence) reduced the intracellular parasitism of the PMM but were inactive during the infection of cardiac cells. Another set of in-vitro and in-vivo studies showed that they do not display a trypanocidal effect on bloodstream trypomastigotes nor exhibit in-vivo efficacy when administered after the parasite inoculation. Our data report the in-vitro activity of PepA and PepB upon the infection of PMM by T. cruzi, possibly triggering the microbicidal arsenal of the host professional phagocytes, capable of controlling parasitic invasion and proliferation.

    Palavras-Chave: protozoa; peptides; chemotherapy; immunology; modulation; infectious diseases

  • IPEN-DOC 28828

    AGUERA, RAUL G.; FREIRES, CAMILA da S.; OLIVEIRA, LUIS O. de; MONTEIRO, LUCILENA R. ; LINI, RENATA S.; ROMOLI, JESSICA C.Z.; FREIRE, BRUNA M.; NERILO, SAMUEL B.; MACHINSKI JUNIOR , MIGUEL; BATISTA, BRUNO L.; MOSSINI, SIMONE A.G.. Risk evaluation of occupational exposure of southern Brazilian flower farmers to pesticides potentially leading to cholinesterase inhibition and metals exposure. Environmental Toxicology and Pharmacology, v. 93, p. 1-9, 2022. DOI: 10.1016/j.etap.2022.103874

    Abstract: This work presents a frequency matched observational study comparing flower farmers exposed to pesticides and unexposed individuals as controls. All subjects were interviewed before plasma and urine collection. Manganese and Zinc were measured in theses samples by using dynamic reaction cell inductively coupled mass spectrometry. Cholinesterase activity was analyzed through spectrophotometry by using a modified version of the Ellman method. Seventy-eight percent of subjects reported occupational contact with pesticides, from which 37% reported exposure for over 9 years. Flower farms farmers had increased odds of having headache and irritability, respectively, by factors of 6.2 and 2.4 than the control subjects. While the odds of exposed subjects to have insomnia was smaller than control subjects by a factor of 0.34. Exposure to pesticides had a significant effect regarding the plasmatic plasma and urinary manganese levels and whole blood cholinesterase activity (p < 0.05). High levels of plasma and urinary manganese, as well as cholinesterase inhibition in whole blood, were evident in the flower farmers who participated in the study.

    Palavras-Chave: occupational safety; metals; occupational exposure; horticulture; pesticides; cholinesterase; enzyme inhibitors

  • IPEN-DOC 28827

    SEGUEL, RODRIGO J.; GALLARDO, LAURA; OSSES, MAURICIO; ROJAS, NESTOR Y.; NOGUEIRA, THIAGO; MENARES, CAMILO; ANDRADE, MARIA de F.; BELALCAZAR, LUIS C.; CARRASCO, PAULA; ESKES, HENK; FLEMING, ZOE L.; HUNEEUS, NICOLAS; IBARRA-ESPINOSA, SERGIO; LANDULFO, EDUARDO ; LEIVA, MANUEL; MANGONES, SONIA C.; MORAIS, FERNANDO G. ; MOREIRA, GREGORI A.; PANTOJA, NICOLAS; PARRAGUEZ, SANTIAGO; ROJAS, JHOJAN P.; RONDANELLI, ROBERTO; ANDRADE, IZABEL da S. ; TORO, RICHARD; YOSHIDA, ALEXANDRE C. . Photochemical sensitivity to emissions and local meteorology in Bogotá, Santiago, and São Paulo: an analysis of the initial COVID-19 lockdowns. Elementa: Science of the Anthropocene, v. 10, n. 1, p. 1-20, 2022. DOI: 10.1525/elementa.2021.00044

    Abstract: This study delves into the photochemical atmospheric changes reported globally during the pandemic by analyzing the change in emissions from mobile sources and the contribution of local meteorology to ozone (O3) and particle formation in Bogotá (Colombia), Santiago (Chile), and São Paulo (Brazil). The impact of mobility reductions (50%–80%) produced by the early coronavirus-imposed lockdown was assessed through high-resolution vehicular emission inventories, surface measurements, aerosol optical depth and size, and satellite observations of tropospheric nitrogen dioxide (NO2) columns. A generalized additive model (GAM) technique was also used to separate the local meteorology and urban patterns from other drivers relevant for O3 and NO2 formation. Volatile organic compounds, nitrogen oxides (NOx), and fine particulate matter (PM2.5) decreased significantly due to motorized trip reductions. In situ nitrogen oxide median surface mixing ratios declined by 70%, 67%, and 67% in Bogotá, Santiago, and São Paulo, respectively. NO2 column medians from satellite observations decreased by 40%, 35%, and 47%, respectively, which was consistent with the changes in mobility and surface mixing ratio reductions of 34%, 25%, and 34%. However, the ambient NO2 to NOx ratio increased, denoting a shift of the O3 formation regime that led to a 51%, 36%, and 30% increase in the median O3 surface mixing ratios in the 3 respective cities. O3 showed high sensitivity to slight temperature changes during the pandemic lockdown period analyzed. However, the GAM results indicate that O3 increases were mainly caused by emission changes. The lockdown led to an increase in the median of the maximum daily 8-h average O3 of between 56% and 90% in these cities.

    Palavras-Chave: meteorology; ozone; nitrogen dioxide; emission; mobile pollutant sources; coronaviruses; air pollution; air quality; urban areas; quarantine

  • IPEN-DOC 28826

    SILVA, REJANE M.P. da ; IZQUIERDO, JAVIER; MILAGRE, MARIANA X. ; ANTUNES, RENATO A.; SOUTO, RICARDO M.; COSTA, ISOLDA . Development of an Al3+ ion-selective microelectrode for the potentiometric microelectrochemical monitoring of corrosion sites on 2098-T351 aluminum alloy surfaces. Electrochimica Acta, v. 415, p. 1-8, 2022. DOI: 10.1016/j.electacta.2022.140260

    Abstract: A novel potentiometric Al3+−ion selective microelectrode (ISME), with internal solid contact, based on the use of a neutral carrier morin as ionophore is reported. The ability of the ISME to image local ion concentration distributions was tested on aluminum alloy surfaces freely corroding in an aqueous solution containing chloride ions. The microelectrode was then used as the sensing tip for scanning electrochemical microscopy (SECM) in potentiometric operation to monitor the reactive sites associated with the dissolution of aluminum that developed in the 2098−T351 Al−Cu−Li alloy as a result of welding by the Friction Stir Welding (FSW) process. The ISME detected differences in the local concentrations of Al3+ species arising from the 2098−T351 Al−Cu−Li alloy (base material) and from the coupled weld joint/heat affected zones (WJ/HAZ) of the alloy produced by the FSW process. More active domains for Al3+ dissolution were found in the HAZ regions coupled to WJ, more specially in the HAZ of the advancing side (AS). These results demonstrate that the Al3+−ISME presented in this work can be used to monitor corrosion sites on aluminum alloys surfaces with combined chemical and spatial resolution.

    Palavras-Chave: ion-selective electrodes; aluminium alloys; corrosion; electrochemistry; welding; friction

  • IPEN-DOC 28825

    NARIO, ARIAN P. ; WOODFIELD, JENILEE; SANTOS, SOFIA N. dos ; BERGMAN, CODY; WUEST, MELINDA; ARAUJO, YASNIEL B. ; LAPOLLI, ANDRE L. ; WEST, FREDERICK G.; WUEST, FRANK; BERNARDES, EMERSON S. . Synthesis of a 2‑nitroimidazole derivative N‑(4‑[18F]fluorobenzyl)‑2‑(2‑nitro‑1H‑imidazol‑1‑yl)‑acetamide ([18F]FBNA) as PET radiotracer for imaging tumor hypoxia. EJNMMI Radiopharmacy and Chemistry, v. 7, n. 1, p. 1-16, 2022. DOI: 10.1186/s41181-022-00165-0

    Abstract: Background: Tissue hypoxia is a pathological condition characterized by reducing oxygen supply. Hypoxia is a hallmark of tumor environment and is commonly observed in many solid tumors. Non-invasive imaging techniques like positron emission tomography (PET) are at the forefront of detecting and monitoring tissue hypoxia changes in vivo. Results: We have developed a novel 18F-labeled radiotracer for hypoxia PET imaging based on cytotoxic agent benznidazole. Radiotracer N-(4-[18F]fluorobenzyl)-2-(2-nitro-1H-imidazol-1-yl)acetamide ([18F]FBNA) was synthesized through acylation chemistry with readily available 4-[18F]fluorobenzyl amine. Radiotracer [18F]FBNA was obtained in good radiochemical yields (47.4 ± 5.3%) and high radiochemical purity (> 95%). The total synthesis time was 100 min, including HPLC purification and the molar activity was greater than 40 GBq/µmol. Radiotracer [18F]FBNA was stable in saline and mouse serum for 6 h. [18F]FBNA partition coefficient (logP = 1.05) was found to be more lipophilic than [18F]EF-5 (logP = 0.75), [18F]FMISO (logP = 0.4) and [18F]FAZA (logP =  − 0.4). In vitro studies showed that [18F]FBNA accumulates in gastric cancer cell lines AGS and MKN45 under hypoxic conditions. Conclusions: Hence, [18F]FBNA represents a novel and easy-to-prepare PET radioligand for imaging hypoxia.

    Palavras-Chave: anoxia; nitro compounds; imidazoles; acetamide; positron computed tomography; oxygen; radiopharmaceuticals

  • IPEN-DOC 28824

    BERNARDES, EMERSON ; CARAVAN, PETER; DAM, R.M. van; DEUTHER-CONRAD, WINNIE; ELLIS, BEVERLEY; FURUMOTO, SHOZO; GUILLET, BENJAMIN; HUANG, YA-YAO; JIA, HONGMEI; LAVERMAN, PETER; LI, ZIJING; LIU, ZHAOFEI; LODI, FILIPPO; MIAO, YUBIN; PERK, LARS; SCHIRRMACHER, RALF; VERCOULLIE, JOHNNY; YANG, HUA; YANG, MIN; YANG, XING; ZHANG, JUNBO; ZHANG, MING-RONG; ZHU, HUA. Highlight selection of radiochemistry and radiopharmacy developments by editorial board. EJNMMI Radiopharmacy and Chemistry, v. 7, n. 1, p. 1-17, 2022. DOI: 10.1186/s41181-022-00162-3

    Abstract: Background: The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biyearly highlight commentary to update the readership on trends in the field of radiopharmaceutical development. Results: This commentary of highlights has resulted in 23 different topics selected by each member of the Editorial Board addressing a variety of aspects ranging from novel radiochemistry to first in man application of novel radiopharmaceuticals and also a contribution in relation to MRI-agents is included. Conclusion: Trends in (radio)chemistry and radiopharmacy are highlighted demonstrating the progress in the research field being the scope of EJNMMI Radiopharmacy and Chemistry.

    Palavras-Chave: radiopharmaceuticals; radiochemistry; antigens; receptors; imidazoles; nitro compounds

  • IPEN-DOC 28823

    ARAUJO, GUILHERME R.S. de; MACIEIRA, GIVALDA M. da C.; OLIVEIRA, DAYANE X. de; MATOS, SAULO S.; SANTOS, QUESIA N. dos; OTUBO, LARISSA ; ARAUJO, ADRIANO A. de S.; DUARTE, MARCELO C.; LIRA, ANA A.M.; NUNES, ROGERIA de S.; SARMENTO, VICTOR H.V.. Microemulsions formed by PPG-5-CETETH-20 at low concentrations for transdermal delivery of nifedipine: structural and in vitro study. Colloids and Surfaces B: Biointerfaces, v. 214, p. 1-9, 2022. DOI: 10.1016/j.colsurfb.2022.112474

    Abstract: Nifedipine is a potent anti-hypertensive, which is poorly orally bioavailable on account of first-pass metabolism, short half-life, and low water solubility. This study aimed to develop a microemulsified system with low surfactant concentration and to evaluate the influence of microemulsion (ME) phase behavior on skin permeation of nifedipine, as drug model. Thereafter, MEs were obtained using PPG-5-CETETH-20, oleic acid, and phosphate buffer at pH 5.0. The selected MEs were isotropic, with droplet diameters less than 10 nm, polydispersity index < 0.25, and pH between 5.0 and 5.2. MEs presented low viscosity and Newtonian behavior. SAXS results confirmed bicontinuous and oil-in-water (o/w) MEs formation. The presence of the drug promoted only very slight modifications in the ME structure. The MEs presented ability to deliver nifedipine via the transdermal route when in comparison with the control. Nevertheless, the skin permeated and retained amounts from the o/w and bicontinuous formulations did not differ significantly. The ATR-FTIR demonstrated that both formulations promoted fluidization and disorganization of lipids and increased the drug diffusion and partition coefficients in the skin. In conclusion, PPG-5-CETETH-20 MEs obtained proved to be effective skin permeation enhancers, acting by rising the coefficients of partition and diffusion of the nifedipine in the skin.

    Palavras-Chave: emulsions; nanotechnology; surfactants; drug delivery

  • IPEN-DOC 28822

    COSTA-SILVA, D.L. ; BARTOLOME, J.F.; SILVA, A.C. ; MELLO-CASTANHO, S. . Structural and thermal influence of niobia in aluminoborosilicate glasses. Ceramics International, v. 48, n. 13, p. 18433-18440, 2022. DOI: 10.1016/j.ceramint.2022.03.112

    Abstract: The addition of small amounts of niobia (Nb2O5) in borosilicate glasses was explored. By analysis on thermal and structural changes, we found evidences that niobium integrates the glass structure in octahedral NbO6 coordination. Adding up to 8.0 mol% of Nb2O5, the oxide partially ruptured the glass structure, interfering in the BO3/ BO4 ratio, but the predominant network configuration was maintained. Thermally, there was an increase in the processing interval and the glasses became more resistant against crystallization, with the presence of niobia. Also, the oxide contributed to a notable decrease in the viscosity of the melts. The improvement of such properties were obtained by the controlled dispersion of the oxide in the glass network structure, avoiding large areas of phase-to-phase separation to preserve the desired ability of these glasses to incorporate a wide range of elements.

    Palavras-Chave: borosilicate glass; niobium oxides; aluminium oxides; raman spectra

  • IPEN-DOC 28821

    ANDRADE, DELVONEI A. de ; ALMEIDA, MADISON C. de ; ALONSO, VANESSA M. ; PAIXAO, CLAUDIA M. ; ARQUINTO, JULIANA ; KOTANI, PALOMA O. ; MARINHO, THAYNA C. . Very high temperature reactor (VHTR): a proposal to generation IV reactors / Reactor a temperatura muito elevada (VHTR) - uma proposta para reactores da geração IV. Brazilian Journal of Development, v. 8, n. 3, p. 17576-17588, 2022. DOI: 10.34117/bjdv8n3-139

    Abstract: The Generation IV reactors depict a revolution in terms of electricity supply for the future. The proof of concept originated in the Generation IV forum, which listed six possible technological routes for a future of nuclear generation based on fissile material, which includes safety requirements, nuclear energy efficiency and less waste generation. These are the very high temperature reactor (VHTR); supercritical water-cooled reactor (SCWR); molten salt reactor (MSR); gas-cooled fast reactor (GFR); sodium cooled fast reactor (SFR); and lead-cooled fast reactor (LFR). The present study explored the possibilities, the obstacles, as well as the challenges to be overcome, for the Very High Temperature Reactor (VHTR). VHTR technology seems to be versatile; it originates on the advancement of another type, the High Temperature Reactor (HTR). USA, Germany and UK were main countries in this avant-garde research. In addition to generating electrical energy, VHTR can provide heat for industrial sectors and other applications. Like any nuclear technology, challenges regarded to safety and the environment are key points in the implementation of the system. VHTR was here prospected, with its “pros and cons”; as a promising way to a safe nucleoelectric energy. Summarizing, VHTR is shown as a possible alternative, as long as studies of high-strength materials go ahead. In short, the reactor becomes a viable source of thermonuclear generation, also associated with hydrogen production.

    Palavras-Chave: graphite; htgr type reactors; hydrogen production; neutron flux; reactor operation; reviews; technology assessment; thermal efficiency

  • IPEN-DOC 28820

    MELO, CAMILA G. ; ROSA, JORGE M. ; BORRELY, SUELI I. ; PEREIRA, MARIA da C.C. . Toxicidade do efluente têxtil com corante reactive blue 21 submetido à irradiação por feixe de elétrons / Toxicity of reactive blue 21 dye textile effluent subjected to electron beam irradiation. Brazilian Journal of Development, v. 8, n. 4, p. 31191-31199, 2022. DOI: 10.34117/bjdv8n4-551

    Abstract: O setor têxtil se destaca na economia de muitos países e por questões ambientais relacionadas à sua cadeia produtiva. A etapa de beneficiamento secundário, em especial o processo de tingimento, além de consumir muita água, utiliza inúmeros insumos químicos, gerando efluentes com potencial tóxico e desequilíbrio às condições de vida do corpo receptor. Diante disso, o objetivo do estudo foi avaliar a toxicidade do efluente têxtil, com o corante Reactive Blue 21, antes e após tratamento por irradiação com feixe de elétrons. O efluente do tingimento otimizado com o corante Reactive Blue 21 foi submetido à irradiação por feixe de elétrons e, posteriormente, avaliado e comparado à amostra sem tratamento, em relação a sua toxicidade aguda com os organismos Daphnia similis e Vibrio fischeri. Os resultados apontaram maior sensibilidade da bactéria luminescente Vibrio fischeri ao efluente, com um valor de CE50 de 0,43% para a amostra sem tratamento e de 8,89%. Já o microcrustáceo Daphnia similis, apresentou para a amostra sem tratamento 4,79% e 12,64% de CE50.O processo de tratamento por irradiação se mostrou eficaz para a redução da toxicidade no efluente analisado, com uma eficácia de mais de 60% no tratamento para ambos os organismos.

    Palavras-Chave: ionizing radiations; toxicity; dyes; textile industry; liquid wastes; materials testing

  • IPEN-DOC 28819

    ANDRADE, DELVONEI A. de ; FREIRE, LUCIANO O.; SANTOS, CLAUDIO S.. Functional analysis, diversity and defense-in-depth principle applied for instrumentation and control architecture in accordance with U.S.NRC / Análise funcional, diversidade e princípio da defesa em profundidade aplicado à arquitectura de instrumentação e controlo em conformidade com o U.S.NRC. Brazilian Journal of Development, v. 8, n. 4, p. 31731-31738, 2022. DOI: 10.34117/bjdv8n4-586

    Abstract: According to IAEA (2020), a large number of nuclear power plants (NPP) is completing 30 to 40 years of operation, and many of them can extend the lifetime for variable periods of operation. Besides that, new applications and methods of NPP design are in direction of adopting small modular reactors (SMR) to optimize the NPP projects in relation to cost and safety (Black et al., 2021). Other way is to apply NPP in naval plants, providing efficient manners to generate energy (Freire, 2018). All these ways can make nuclear energy a viable alternative, and consequently to contribute with low carbon power demands, and stabilize the global energy matrix helping to meet climate goals in the next decades (IAEA, 2020). One of the sensing points in NPP project nowadays is the introduction of advanced digital I&C technologies (Santos, 2021). In digital I&C design based on nuclear normative basis, it is imperative to be adherent with the safety and human factors engineering (HFE) requirements. This paper proposes the formalization of a plant-level Functional Analysis (FA) methodology with Diversity and Defense-in-Depth (D3) principles, considering the U.S.NRC normative basis.

    Palavras-Chave: functional analysis; human factors engineering; nuclear power plants; reactor control systems; reactor instrumentation; reactor safety; us nrc

  • IPEN-DOC 28818

    OLIVEIRA, VINICIUS G. de ; SILVA, LEONARDO G. de A. e ; MARINUCCI, GERSON . Creep analysis of a GRP cylinder under hydrostatic test / Análise de fluência de um cilindro GRP sob teste hidrostático. Brazilian Journal of Development, v. 8, n. 3, p. 20094-20100, 2022. DOI: 10.34117/bjdv8n3-284

    Abstract: The GRP (Glass Reinforced Polymer) has been widely used in several industrial applications mainly due to its low cost, high availability, and easy manufacturing process. The matrix made by a combination of glass fibers and epoxy offers good engineering properties for the composite material. This study aims to investigate the creep behavior of a glass fiber/epoxy composite cylinder when it was subjected to hydrostatic pressure at room temperature, and when heated at 50ºC. The geometrical viscoelastic deformation was identified by processing signal data positioned on the cylinder surface. Then, electronic data processing was performed to obtain the characteristic of the creep phase phenomenon attributed to this polymeric composite. The cylindrical specimen has been manufactured using a 4-axis CNC (Computer Numeric Control) filament winding machine, which is equipment designed to produce cylindrical components in the composite industry. A creep test was performed by submitting the cylinder to a hydrostatic load for 500 hours, with a controlled injection of fluid up to a 50 bar pressure. Moreover, fiber volume fraction and composite density were determined to control de manufacturing parameters. The results showed that the glass transition temperature of the composite was 120°C. This also indicated a high level of reliability in the manufacturing parameters of the composite specimen. In the experiment carried out at 50ºC, the polymer matrix showed a loss of stiffness, which contributed to increased strain levels in the composite material. The structure did not show a significant creep effect after 500 hours, ensuring good dimensional and structural stability from the cylinder. Once the creep test finished, the cylinder was submitted to increase the pressure level to rupture. The microstructure was also evaluated using scanning electron microscopy (SEM). The SEM analyses presented a good agreement with the filament winding manufacturing parameters and showed the excellent quality of impregnation between glass fiber and epoxy resin applied on the cylinder specimen. The images presented evidence of an excellent adhesion of the fiber into the matrix, contributing to a good performance of the composite.

    Palavras-Chave: creep; composite materials; glass; fibers; polymers; filaments; winding machines

  • IPEN-DOC 28817

    ZANINI, NATHALIA A. ; CARAMEL-JUVINO, AMANDA ; ANA, PATRICIA A.; ZEZELL, DENISE M. . Erbium laser in the debonding of ceramics: a literature review. Brazilian Dental Science, v. 25, n. 2, p. 1-13, 2022. DOI: 10.4322/bds.2022.e3154

    Abstract: Background: The debonding of crowns and ceramic veneers with laser is already a reality in the clinic. It presents benefits in comparison to traditional removal with the use of a rotating instrument; however, there is still no consolidated protocol and many professionals use it without the necessary scientific basis. Objective: The aim of this work was to perform a literature review on the debonding of indirect ceramic restorations using the Er:YAG and Er,Cr:YSGG lasers to provide clinical professionals and the scientific community a careful analysis, and also to guiding the use of irradiation at laser for such procedures. Methods: Bibliographic searches were performed in the following databases: Pubmed, Web of Science and Google Scholar. According to the inclusion criteria adopted, twenty-seven clinical and in vitro studies were selected in the period from 2007 to 2021. In the present work, the composition of the crowns and facets, as well as the types of cement and the laser irradiation protocols adopted in the selected studies is detailed. Conclusions: It was concluded that the use of erbium lasers for debonding of indirect ceramic restorations proved to be more selective and conservative when compared to removal with a rotary diamond instrument. Furthermore, it was shown to be in more efficient in debonding different types of ceramics. However, there are great variations in the “debonding” protocols, which emphasizes the need for further studies that seek to standardize the irradiation protocols considering the different clinical situations.

    Palavras-Chave: ceramics; lasers; bonding; erbium

  • IPEN-DOC 28816

    VILLAGRAN, XIMENA S.; ALVES, MARCONY L.; KATER, THIAGO; SILVA, KELLY B.V. da; BATALLA, NICOLAS ; COSTA, MARCELO da; COSTA, JESSICA; ERLER, DIONNE M.A.; FERREIRA, MARIANE P.; MAGON, PATRICIA; REYS, ARANDA C. dos; STRAIOTO, HARUAN; TOGNOLI, ANDERSON R.; STRAUSS, ANDRE; LAMA, ELIANE A. del; MARTINS, LUCELENE; TEIXEIRA-BASTOS, MARCIO; NEVES, EDUARDO G.; ZIMPEL, CARLOS; PUGLIESE, FRANCISCO. Petrografia de cerâmicas da fase Bacabal (sambaqui Monte Castelo): um dos mais antigos usos de cauixi na Amazônia / Ceramic petrography of the Bacabal phase (sambaqui Monte Castelo): one of the oldest uses of freshwater sponge spicules in the Amazon. Boletim do Museu Paraense Emilio Goeldi: Ciências Humanas, v. 17, n. 1, p. 1-32, 2022. DOI: 10.1590/2178-2547-BGOELDI-2020-0120

    Abstract: Este artigo apresenta os resultados da análise petrográfica realizada em 22 fragmentos de cerâmicas provenientes da fase Bacabal, do sambaqui Monte Castelo (Rondônia), uma das cerâmicas mais antigas da Amazônia, datada de mais de 4.000 anos AP. A análise petrográfica confirmou a alta frequência de espículas de espongiários dulcícolas (cauixi) como antiplástico, com dados inéditos sobre a distribuição das espículas, que permitem inferir o processo de preparação da pasta cerâmica e de manufatura do vasilhame. A mesma proporção entre matriz argilosa e cauixi foi detectada ao longo de todas as camadas Bacabal, independente de variações individuais para cada elemento. Isso permite supor a existência de uma receita de cerâmica mantida ao longo da ocupação Bacabal do sítio. O mesmo tipo de cauixi descrito na pasta cerâmica foi identificado em sedimentos argilosos prospectados na região, embora em frequência menor. Assim, a fabricação das cerâmicas Bacabal poderia ter envolvido uma combinação entre: seleção de argilas naturalmente ricas em espículas e cauixi adicionado intencionalmente. O cauixi na fase Bacabal representa um caso excepcional para a investigação sobre o desenvolvimento de tecnologias cerâmicas, sustentadas pela utilização desses antiplásticos, que se tornaram populares durante o Holoceno Superior nas terras baixas da América do Sul.

    Palavras-Chave: ceramics; petrography; cultural objects; archaeological specimens; archaeological sites

  • IPEN-DOC 28815

    MONTELEONE-CASSIANO, ANA C.; DERNOWSEK, JANAINA A. ; MASCARENHAS, ROMARIO S.; ASSIS, AMANDA F.; PITOL, DIMITRIUS; MOREIRA, NATALIA C.S.; SAKAMOTO-HOJO, ELZA T.; ISSA, JOAO P.M.; DONADI, EDUARDO A.; PASSOS, GERALDO A.. The absence of the autoimmune regulator gene (AIRE) impairs the three‑dimensional structure of medullary thymic epithelial cell spheroids. BMC Molecular and Cell Biology, v. 23, n. 1, p. 1-17, 2022. DOI: 10.1186/s12860-022-00414-9

    Abstract: Background: Besides controlling the expression of peripheral tissue antigens, the autoimmune regulator (AIRE) gene also regulates the expression of adhesion genes in medullary thymic epithelial cells (mTECs), an essential process for mTEC-thymocyte interaction for triggering the negative selection in the thymus. For these processes to occur, it is necessary that the medulla compartment forms an adequate three-dimensional (3D) architecture, preserving the thymic medulla. Previous studies have shown that AIRE knockout (KO) mice have a small and disorganized thymic medulla; however, whether AIRE influences the mTEC-mTEC interaction in the maintenance of the 3D structure has been little explored. Considering that AIRE controls cell adhesion genes, we hypothesized that this gene affects 3D mTEC-mTEC interaction. To test this, we constructed an in vitro model system for mTEC spheroid formation, in which cells adhere to each other, establishing a 3D structure. Results: The comparisons between AIRE wild type (AIREWT) and AIRE KO (AIRE−/−) 3D mTEC spheroid formation showed that the absence of AIRE: i) disorganizes the 3D structure of mTEC spheroids, ii) increases the proportion of cells at the G0/G1 phase of the cell cycle, iii) increases the rate of mTEC apoptosis, iv) decreases the strength of mTECmTEC adhesion, v) promotes a differential regulation of mTEC classical surface markers, and vi) modulates genes encoding adhesion and other molecules. Conclusions: Overall, the results show that AIRE influences the 3D structuring of mTECs when these cells begin the spheroid formation through controlling cell adhesion genes.

    Palavras-Chave: spheroids; genes; immune system diseases; adhesion; epithelium; cell cultures

  • IPEN-DOC 28814

    COELHO, EDNEI; REIS, TATIANA A.; COTRIM, MARYCEL ; MULLAN, THOMAS K.; RENSHAW, JOANNA; RIZZUTTO, MARCIA; CORREA, BENEDITO. Talaromyces amestolkiae uses organic phosphate sources for the treatment of uranium‑contaminated water. Biometals, v. 35, n. 2, p. 335-348, 2022. DOI: 10.1007/s10534-022-00374-9

    Abstract: Fungi have received particular attention in regards to alternatives for bioremediation of heavy metal contaminated locales. Enzymes produced by filamentous fungi, such as phosphatases, can precipitate heavy metal ions in contaminated environments, forming metal phosphates (insoluble). Thus, this research aimed to analyze fungi for uranium biomineralization capacity. For this, Gongronella butleri, Penicillium piscarium, Rhodotorula sinensis and Talaromyces amestolkiae were evaluated. Phytate and glycerol 2-phosphate were used as the phosphate sources in the culture media at pH 3.5 and 5.5, with and without uranium ions. After 4 weeks of fungal growth, evaluated fungi were able to produce high concentrations of phosphates in the media. T. amestolkiae was the best phosphate producer, using phytate as an organic source. During fungal growth, there was no change in pH level of the culture medium. After 3 weeks of T. amestolkiae growth in medium supplemented with phytate, there was a reduction between 20 and 30% of uranium concentrations, with high precipitation of uranium and phosphate on the fungal biomass. The fungi analyzed in this research can use the phytic acid present in the medium and produce high concentrations of phosphate; which, in the environment, can assist in the heavy metal biomineralization processes, even in acidic environments. Such metabolic capabilities of fungi can be useful in decontaminating uranium-contaminated environments.

    Palavras-Chave: fungi; water treatment; waste water; uranium; phosphates; organic compounds; bioadsorbents

  • IPEN-DOC 28813

    MOREIRA, GREGORI de A. ; OLIVEIRA, AMAURI P. de; SANCHEZ, MACIEL P.; CODATO, GEORGIA; LOPES, FABIO J. da S. ; LANDULFO, EDUARDO ; MARQUES FILHO, EDSON P.. Performance assessment of aerosol-lidar remote sensing skills to retrieve the time evolution of the urban boundary layer height in the Metropolitan Region of São Paulo City, Brazil. Atmospheric Research, v. 277, p. 1-16, 2022. DOI: 10.1016/j.atmosres.2022.106290

    Abstract: This paper investigates the performance of seven methods of retrieving the planetary boundary layer height (PBLH) from lidar measurements carried out in the Metropolitan Region of S˜ao Paulo (MRSP) during two MCITY-BRAZIL field campaigns of 2013. The performance is objectively assessed considering as reference the PBLH retrieved from rawinsonde carried out every 3 h during these campaigns. The role of clouds and aerosol load in the performance of the seven methods is analysed considering three case study scenarios representative of typical atmospheric conditions in the MRSP: (a) winter clean atmosphere, (b) summer low clouds and aerosol multilayers, (c) summer sea-breeze intrusion. Corroborating the case study results, the objective analysis indicated that most of the lidar methods retrieved PBLH closer to the top of the entrainment zone than the mixed layer, contradicting their definition. During daytime, the Wavelet Covariance Transform Method performs better than all the other six methods. The Inflexion Point Method performed better to estimate the Residual Layer height during night-time. In average, the diurnal evolution of the PBLH and its local rate of change based on lidar and rawinsonde measurements are in agreement.

    Palavras-Chave: aerosols; remote sensing; optical radar; urban areas; boundary layers

  • IPEN-DOC 28812

    MOREIRA, GREGORI de A. ; OLIVEIRA, AMAURI P. de; CODATO, GEORGIA; SANCHEZ, MACIEL P.; TITO, JANET V.; SILVA, LEONARDO A.H. e; SILVEIRA, LUCAS C. da; SILVA, JONATAN J. da ; LOPES, FABIO J. da S. ; LANDULFO, EDUARDO . Assessing spatial variation of PBL height and aerosol layer aloft in São Paulo Megacity using simultaneously two lidar during winter 2019. Atmosphere, v. 13, n. 4, p. 1-16, 2022. DOI: 10.3390/atmos13040611

    Abstract: This work presents the use of two elastic lidar systems to assess the horizontal variation of the PBL height (PBLH) and aerosol layer aloft in the São Paulo Megacity. These two lidars performed simultaneous measurements 10.7 km apart in a highly urbanized and relatively flat area of São Paulo for two winter months of 2019. The results showed that the PBLH differences display diurnal variation that depends on the PBL during daytime growth phases. Cloud and sea breeze effects control most of PBLH variation. In the absence of cloud and sea breeze, the maximum difference (~300 m) occurs in the rapid development stage and is due to topographic effects. When the PBL approaches its maximum daily value, it tends to level off with respect to the topography. In addition, it was presented a method that combines elastic lidar (to detect an aerosol layer) and satellite data (to classify such a layer from Aerosol Optical Depth (AOD) and Aerosol Index (AI) information) for the detection of biomass burning events. This methodology demonstrated that the variations caused by Biomass Burning in AOD and AI enable both the detection of aerosol plumes originating from biomass burning and the identification of their origin.

    Palavras-Chave: boundary layers; earth atmosphere; biomass; burns; urban areas; optical radar

  • IPEN-DOC 28811

    MILAGRE, MARIANA X. ; PEREIRA, MARCO S. ; GOMES, ANTONIO A. ; SCAPIN, MARCOS ; FRANCO, MARGARETH ; YOKAICHIYA, FABIANO; GENEZINI, FREDERICO ; COSTA, ISOLDA . Corrosion characterization of the 6061 Al–Mg–Si alloy in synthetic acid rain using neutron tomography. Applied Radiation and Isotopes, v. 184, p. 1-8, 2022. DOI: 10.1016/j.apradiso.2022.110197

    Abstract: Neutron tomography has gained increasing importance as an imaging technique for materials characterization. In general, neutron beams are able to show microstructure features of hydrogenous materials, even enfolded with thick metal layers. In the present paper, neutron tomography and observation of cross section images were successfully applied to investigate the corrosion features of the 6061 Al–Mg–Si alloy. The results showed good agreement between neutron 3D tomography and the cross section images obtained in the high attenuation areas of the samples, whereas significant differences in depth of corrosion penetration were obtained between the results from Neutron Tomography and 3D optical profilometry.

    Palavras-Chave: aluminium alloys; corrosion resistance; three-dimensional calculations; stresses; neutrons; tomography

  • IPEN-DOC 28810

    AZEREDO, NATHALIA F.B. ; SANTOS, MAURO S.F.; SEMPIONATTO, JULIANE R.; WANG, JOSEPH; ANGNES, LUCIO. Screen-printed technologies combined with flow analysis techniques: moving from benchtop to everywhere. Analytical Chemistry, v. 94, n. 1, p. 250-268, 2022. DOI: 10.1021/acs.analchem.1c02637

    Abstract: Screen-printed electrodes (SPEs) coupled with flow systems have been reported in recent decades for an evergrowing number of applications in modern electroanalysis, aiming for portable methodologies. The information acquired through this combination can be attractive for future users with basic knowledge, especially due to the increased measurement throughput, reduction in reagent consumption and minimal waste generation. The trends and possibilities of this set rely on the synergistic behavior that maximizes both SPE and flow analyses characteristics, allowing mass production and automation. This overview addresses an in-depth update about the scope of samples, target analytes, and analytical throughput (injections per hour, limits of detection, linear range, etc.) obtained by coupling injection techniques (FIA, SIA, and BIA) with SPE-based electrochemical detection.

    Palavras-Chave: electrodes; electrochemistry; screen printing; coatings

  • IPEN-DOC 28809

    LEBRE, DANIEL T. ; THIPE, VELAPHI C. ; COTRIM, MARYCEL E.B. ; BUSTILLOS, JOSE O.V. . Use of sugar cane bagasse as solid extraction phase sorbent to analyze hormones from industrial effluent. ACS Omega, v. 7, n. 12, p. 10069-10076, 2022. DOI: 10.1021/acsomega.1c06064

    Abstract: Sugar cane bagasse (SCB) is an abundant byproduct of sugar and bioethanol mills. It has been effectively used as a low-cost biosorbent to remove hazardous chemical compounds from a variety of effluent sources. Herein, we report on the preparation of SCB and its use as a solid phase extraction (SPE) sorbent to retain synthetic hormones (ethinylestradiol, drospirenone, and levonorgestrel) from industrial pharmaceutical plant effluent samples prior to LC–MS/MS quantitative analysis. We evaluated the reproducibility and recoveries and accuracy data analyses were compared with that of commercial SPE (cSPE) cartridges. The results from the evaluated parameters indicated that the SCB bed had an efficiency of >99%, comparable to that of cSPE cartridges, demonstrating the applicability and feasibility of this material as an effective and green chemistry alternative, as well as its biosorbent potential to remove hormones from industrial pharmaceutical effluent.

    Palavras-Chave: sugar cane; bagasse; bioethanol; hormones; bioremediation; liquid wastes

  • IPEN-DOC 28674

    SILVA, PAULO S.C. da ; EL HAJJ, THAMMIRIS M.; DANTAS, G.A.S.A.; DELBONI JUNIOR, HOMERO; GANDOLLA, MAURO. Activity concentration of the uranium and thorium series and exhalation rates of 222Rn and 220Rn in building material derived from niobium residues. Journal of Building Engineering, v. 46, p. 1-10, 2022. DOI: 10.1016/j.jobe.2021.103657

    Abstract: One way to better manage mining waste may be to reduce its quantity by reusing it. Using waste as construction material in the case of the niobium industry might be feasible, even though it carries radioactive elements. This study evaluates the radiological impact of using niobium waste as a building material. Samples of niobium waste with and without granulometric classification were tested. Moreover, concrete proof bodies, concrete plates, and common commercially available aggregates and cement were radiologically assessed for comparison purposes. The main conclusion is that niobium waste might be both physically and radiologically suitable to manufacture concrete respecting boundary conditions.

    Palavras-Chave: sustainability; niobium; mining; residues; radon 220; radon 222; risk assessment; building materials; naturally occurring radioactive materials; exhalation

  • IPEN-DOC 28771

    VALLINOTO, PRISCILA ; MOREIRA, EDSON G. ; MAIHARA, VERA A. . Estimation of daily dietary intake of essential minerals and trace elements in commercial complementary foods marketed in Brazil. Food Chemistry Advances, v. 1, p. 1-7, 2022. DOI: 10.1016/j.focha.2022.100039

    Abstract: Eating habits influence health and development throughout life and commercial complementary foods are an important part of the diet for many infants. In this study, Ca, Fe, K, Mn, Mg, Na, Se and Zn were determined in twenty-seven Brazilian commercial complementary foods samples by Instrumental Neutron Activation Analysis. Daily dietary intakes of the elements were estimated in three groups aged 6–8 months, 9–11 months and 12–24 months from breastfed and non-breastfed infants and young children. Non-breastfed children presented higher daily dietary intakes for all elements. Daily dietary intakes of Fe, Mg, Mn, Na and Zn did not meet the recommended values for the 6–8 and 9–11 months for the breastfeeding group. Ca, K, Mg, Mn, Na and Zn dietary intakes were below the recommended values for 12–24 months for breastfeeding group. Se daily dietary intakes were inadequate in all studied groups. No investigated element exceeded the upper limits. It was observed that the commercial infant food analyzed do not provide sufficient amount of essential minerals and trace elements for the child healthy development in accordance to the international health recommendations.

    Palavras-Chave: nutrition; diet; intake; minerals; nutrients; neutron activation analysis; children; pediatrics; food industry; insurance

  • IPEN-DOC 28770

    ARAUJO, JOAO V. de S. ; MILAGRE, MARIANA X. ; KLUMPP, RAFAEL E. ; AYUSSO, VICTOR H. ; DONATUS, UYIME ; COSTA, ISOLDA . TSA anodising voltage effects on the near-surface coarse intermetallic particles in the AA2024-T3 and AA2198-T8 alloys. Corrosion Engineering, Science and Technology, v. 57, n. 4, p. 380-396, 2022. DOI: 10.1080/1478422X.2022.2071666

    Abstract: In this study, the behaviour of the micrometric particles of the AA2198-T8 alloy during anodising at various voltages and the effect of anodising voltage on the anodised surface morphology have been investigated in a tartaric-sulfuric acid anodising solution. The results were compared with that of the AA2024-T3 alloy. For the AA2198-T8 alloy, partial dissolution of these particles occurred at 0, 3 and 4 V. Besides, for potentials above 5 V, there is a preferential dissolution of the intermetallic particles. For the AA2024-T3 alloy, the results indicated a total dissolution of the micrometric particles at 0 V and a partial dissolution at 3 V, whereas above 4 V total dissolution occurred. Between 1 and 2 V, no dissolution was observed for both alloys. The preferential dissolution of the micrometric particles resulted in defects in the anodic film and cavities on the anodised surfaces.

    Palavras-Chave: aluminium alloys; intermetallic compounds; particle size; anodization; sulfuric acid; tartaric acid

  • IPEN-DOC 28769

    TEIXEIRA, LUIZ F.S. ; GIGLIOTTI, RODRIGO; FERREIRA, LUANA da S.; BELLINI, MARIA H. . Identification of appropriate housekeeping genes for gene expression studies in human renal cell carcinoma under hypoxic conditions. Molecular Biology Reports, v. 49, p. 3885-3891, 2022. DOI: 10.1007/s11033-022-07236-0

    Abstract: Background: Hypoxia pathways are deregulated in clear renal cell carcinoma (ccRCC) because of the loss of the von Hippel-Lindau tumor suppressor function. Quantitative PCR is a powerful tool for quantifying differential expression between normal and cancer cells. Reliable gene expression analysis requires the use of genes encoding housekeeping genes. Therefore, in this study, eight reference candidate genes were evaluated to determine their stability in 786-0 cells under normoxic and hypoxic conditions. Methods and Results: Four different tools were used to rank the most stable genes—geNorm, NormFinder, BestKeeper, and Comparative Ct (ΔCt), and a general ranking was performed using RankAggreg. According to the four algorithms, the TFRC reference gene was identified as the most stable. There was no agreement among the results from the algorithms for the 2nd and 3rd positions. A general classification was then established using the RankAggreg tool. Finally, the three most suitable reference genes for use in 786-0 cells under normoxic and hypoxic conditions were TFRC, RPLP0, and SDHA. Conclusions: To the best of our knowledge, this is the first study to identify reliable genes that can be used for gene expression analysis in ccRCC in a hypoxic environment.

    Palavras-Chave: kidneys; neoplasms; carcinomas; anoxia; genes; standardization

  • IPEN-DOC 28764

    SOUZA, ALANA G. de; KOMATSU, LUIZ G.H. ; BARBOSA, RENNAN F.S.; PARRA, DUCLERC F. ; ROSA, DERVAL S.. The effect of ZnO nanoparticles as Ag‑carrier in PBAT for antimicrobial films. Polymer Bulletin, v. 79, n. 6, p. 4031-4048, 2022. DOI: 10.1007/s00289-021-03681-2

    Abstract: Zinc oxide (ZnO) and ZnO-silver (ZnO-Ag) nanoparticles (NPs) are widely used in different fields, such as biomedicine and food packaging, due to their recognized antibacterial activity and safety for human health. In this paper, ZnO and ZnO-Ag NPs were incorporated into poly(butylene adipate-co-terephthalate) (PBAT), in two contents (0.5 and 1 wt%), to prepare antibacterial films. The NPs were characterized by TEM and FT-Raman, and the films were analyzed by FT-Raman and FTIR, mechanical properties, SEM–EDS, TGA, DSC, XRD, and antibacterial properties against Escherichia coli. The results indicate that both NPs were physically retained in the polymer structure, with a strong electrostatic interaction between the mixture components, reflecting excellent mechanical behavior. The films showed good thermal stability, without significant changes, and the nanocomposites enhanced PBAT crystallinity from 18 to 23% and 27% for PBAT-ZnO and PBAT-ZnO-Ag films, respectively. The mechanical, thermal, and crystallinity results indicated the excellent potential of NPs in biodegradable films to improve properties and expand applicability. The antimicrobial activity is higher for PBAT-ZnO-Ag films than the pristine PBAT due to the synergic effect between the NPs and the oxidation–reduction potential of each nanoparticle, where the ZnO protect and stabilized the Ag-NPs, acting as an Ag-carrier, enhancing its antimicrobial effects after the film’s preparation and allowing its applicability in biomedical products or food packaging.

    Palavras-Chave: antimicrobial agents; zinc oxides; nanoparticles; silver; polymers; bacteria; escherichia coli

  • IPEN-DOC 28697

    LISBOA, CARINA C. ; OLIVEIRA JUNIOR, OLIVIO P. de ; ANDRADE, DELVONEI A. de . Análises de amostras ambientais para fins de salvaguardas nucleares no Brasil / Analysis of environmental samples for nuclear safeguards purposes in Brazil. Quimica Nova, v. 45, n. 3, p. 355-361, 2022. DOI: 10.21577/0100-4042.20170839

    Abstract: The International Atomic Energy Agency (IAEA) is responsible for preventing the proliferation of nuclear weapons by detecting early the misuse of nuclear material or technology, and by certifying that States are honouring their safeguards obligations. The analysis of environmental samples taken by IAEA inspectors during inspections is a powerful tool for nuclear safeguards. This tool was implemented in 1996, after a successful application in Iraq, when a clandestine nuclear weapons program was discovered. The science involved in this type of analysis depends on highly sensitive and selective analytical measurements for detecting traces of nuclear materials collected in the nuclear facility’s “environment”. The purposes of this article are to draw attention to the relevance of this subject in order to address a significant global problem and to present what have been developed in Brazil. Through compatible results with certified standards and IAEA requirements, Brazil has already demonstrated the potential of measuring the amount and isotopic composition of uranium and plutonium at the levels expected in typical environmental samples. Finally, this work suggests the necessary measurements to implement a reliable and consistent environmental samples program for nuclear safeguards in Brazil.

    Palavras-Chave: environment; environmental materials; sample preparation; nuclear materials possession; safeguard regulations; uranium; plutonium; international cooperation

  • IPEN-DOC 28696

    VIVEIROS, BARBARA V.G. de ; DONATUS, UYIME ; ALENCAR, MAICON C. de ; BERBEL, LARISSA O. ; COSTA, ISOLDA . Comparing the corrosion behaviour of AA2050 and AA7050 aluminium alloys by scanning vibrating electrode and scanning ion-selective electrode techniques. Corrosion Engineering, Science and Technology, v. 57, n. 1, p. 85-96, 2022. DOI: 10.1080/1478422X.2021.1992132

    Abstract: The susceptibility to localised corrosion of the high strength alloys, AA2050-T84 and AA7050-T7451, used in the aerospace industry, was investigated in this study by localised electrochemical techniques, specifically, scanning vibrating electrode technique (SVET) and scanning ion-selective electrode technique (SIET), in 0.005 mol L−1 NaCl solution. The study was initially carried out using both alloys individually and then, coupling the two alloys and evaluating the effect of galvanic coupling between them. The results revealed that the AA2050-T84, being nobler than the AA7050-T7451, presented higher corrosion current density values when tested in isolation and the depth of corrosion penetration was significantly deeper in the AA2050-T84 alloy than in the AA7050-T7451. However, galvanic coupling of the two alloys resulted in cathodic protection of the AA2050-T84 alloy and a reduction in corrosion current densities on both alloys.

    Palavras-Chave: aluminium alloys; corrosion resistance; intergranular corrosion; pitting corrosion; coupling; electrochemical corrosion; electrodes; ion-selective electrodes

  • IPEN-DOC 28694

    CORREA, NICOLI D.G. ; SILVA, FELIPE D. ; VIEIRA, DANIEL P. ; SOARES, CARLOS R.J. ; QUEIROZ, ALVARO A.A. de . In vitro cytotoxic data on Se-methylselenocysteine conjugated to dendritic poly(glycerol) against human squamous carcinoma cells. Journal of Biomaterials Science, Polymer Edition, v. 33, n. 5, p. 651-667, 2022. DOI: 10.1080/09205063.2021.2008788

    Abstract: Polymeric nanoparticles acting as sources of selenium (Se) are currently an interesting topic in cancer chemotherapy. In this study, polyglycerol dendrimer (DPGLy) was functionalized with seleno-methyl-selenocysteine (SeMeCys) by means of Steglich esterification with 4-dimethylaminopyridine/(l-ethyl-3-(3-dimethylaminopropyl)carbodiimide) (EDC/DMAP) and cerium chloride as cocatalyst in acetonitrile at quantitative yields of 98 ± 1%. The SeMeCys coupling DPGLy efficiency vs. time were determined by Fourier Transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–Vis) spectroscopy. The cytotoxic effects of SeMeCys–DPGLy on the Chinese Hamster ovary cell line (CHO-K1) and head and neck squamous cell carcinoma (HNSCC) cells line were assessed by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. No signs of general toxicity of SeMeCys–DPGLy against CHO-K1 cells were detectable at which cell viability was greater than 98%. MTS assays revealed that SeMeCys–DPGLy reduced HNSCC cell viability and proliferation at higher doses and long incubation times.

    Palavras-Chave: selenium; dendrimers; glycerol; toxicity; carcinomas; bioassay; in vitro

  • IPEN-DOC 28693

    SOUZA, CARLA D. de ; BARBEZAN, ANGELICA B. ; ROSERO, WILMMER A.A. ; SANTOS, SOFIA N. dos ; CARVALHO, DIEGO V. de S. ; ZEITUNI, CARLOS A. ; BERNARDES, EMERSON S. ; VIEIRA, DANIEL P. ; SPENCER, PATRICK J. ; RIBEIRO, MARTHA S. ; ROSTELATO, MARIA E.C.M. . Synthesis, in vitro testing, and biodistribution of surfactant-free radioactive nanoparticles for cancer treatment. Nanomaterials, v. 12, n. 2, p. 1-13, 2022. DOI: 10.3390/nano12020187

    Abstract: New forms of cancer treatment, which are effective, have simple manufacturing processes, and easily transportable, are of the utmost necessity. In this work, a methodology for the synthesis of radioactive Gold-198 nanoparticles without the use of surfactants was described. The nuclear activated Gold-198 foils were transformed into H198AuCl4 by dissolution using aqua regia, following a set of steps in a specially designed leak-tight setup. Gold-198 nanoparticles were synthesized using a citrate reduction stabilized with PEG. In addition, TEM results for the non-radioactive product presented an average size of 11.0 nm. The DLS and results for the radioactive 198AuNPs presented an average size of 8.7 nm. Moreover, the DLS results for the PEG-198AuNPs presented a 32.6 nm average size. Cell line tests showed no cytotoxic effect in any period and the concentrations were evaluated. Furthermore, in vivo testing showed a high biological uptake in the tumor and a cancer growth arrest.

    Palavras-Chave: radioactivity; nanoparticles; brachytherapy; neoplasms; testing; in vivo; in vitro; gold 198; distribution

  • IPEN-DOC 28692

    BARROS, L.F. ; DIAS, M.S. ; KOSKINAS, M.F. . Experimental determination of k0 and Q0 values for 121Sb, 123Sb and 130Ba targets applying covariance analysis. Applied Radiation and Isotopes, v. 184, p. 1-7, 2022. DOI: 10.1016/j.apradiso.2022.110122

    Abstract: This work consists of an experimental determination of k0 and Q0 for 121Sb, 123Sb and 130Ba targets. Covariance analysis has been introduced to supply not only the overall uncertainties in these parameters but also their correlations. The irradiations were performed near the core of the IEA-R1 4.5 MW swimming-pool nuclear research reactor of the Nuclear and Energy Research Institute (IPEN-CNEN/SP), in São Paulo, Brazil. The epithermal neutron flux shape parameter, alpha, at the irradiation position is very close to zero, which favors to obtain Q0 values more accurately. Two irradiations were carried out in sequence, using two sets of samples: the first with bare samples and the second inside a Cd cover. The activity measurements were carried out in a previously calibrated HPGe gamma-ray spectrometer. The measurements were corrected for: saturation, decay time, cascade summing, geometry, self-attenuation, measuring time and mass. Standard sources of 152Eu, 133Ba, 60Co and 137Cs traceable to a 4πβ−γ primary system were used to obtain the HPGe gamma-ray peak efficiency as a function of the energy. The experimental efficiency curve was performed by a fourth-degree polynomial fit, in the energy range of the standard sources, 121–1408 keV, it contains all correlations between points. For energies above 1408 keV, the efficiencies were obtained by the Monte Carlo Method. The covariance matrix methodology was applied to all uncertainties involved. The final values for k0 and Q0 were compared with the literature.

    Palavras-Chave: gamma spectroscopy; monte carlo method; monte carlo method; antimony isotopes; barium 130; reactors; antimony 123; antimony 121

  • IPEN-DOC 28691

    KHAN, ZAHID U.; UCHIYAMA, MAYARA K.; KHAN, LATIF U.; ARAKI, KOITI; GOTO, HIRO; FELINTO, MARIA C.F.C. ; SOUZA, ANA O. de; BRITO, HERMI F. de; GIDLUND, MAGNUS. Wide visible-range activatable fluorescence ZnSe:Eu3+/Mn2+@ZnS quantum dots: local atomic structure order and application as a nanoprobe for bioimaging. Journal of Materials Chemistry B, v. 10, n. 2, p. 247-261, 2022. DOI: 10.1039/d1tb01870a

    Abstract: The development of QDs-based fluorescent bionanoprobe for cellular imaging fundamentally relies upon the precise knowledge of particle–cell interaction, optical properties of QDs inside and outside of the cell, movement of a particle in and out of the cell, and the fate of particle. We reported engineering and physicochemical characterization of water-dispersible Eu3+/Mn2+ co-doped ZnSe@ZnS core/shell QDs and studied their potential as a bionanoprobe for biomedical applications, evaluating their biocompatibility, fluorescence behaviour by CytoViva dual mode fluorescence imaging, time-dependent uptake, endocytosis and exocytosis in RAW 264.7 macrophages. The oxidation state and local atomic structure of the Eu dopant studied by X-ray absorption fine structure (XAFS) analysis manifested that the Eu3+ ions occupied sites in both ZnSe and ZnS lattices for the core/shell QDs. A novel approach was developed to relieve the excitation constraint of wide bandgap ZnSe by co-incorporation of Eu3+/Mn2+ codopants, enabling the QDs to be excited at a wide UV-visible range. The QDs displayed tunable emission colors by a gradual increase in Eu3+ concentration at a fixed amount of Mn2+, systematically enhancing the Mn2+ emission intensity via energy transfer from the Eu3+ to Mn2+ ion. The ZnSe:Eu3+/Mn2+@ZnS QDs presented high cell viability above 85% and induced no cell activation. The detailed analyses of QDs-treated cells by dual mode fluorescence CytoViva microscopy confirmed the systematic color-tunable fluorescence and its intensity enhances as a function of incubation time. The QDs were internalized by the cells predominantly via macropinocytosis and other lipid raft-mediated endocytic pathways, retaining an efficient amount for 24 h. The unique color tunability and consistent high intensity emission make these QDs useful for developing a multiplex fluorescent bionanoprobe, activatable in wide-visible region.

    Palavras-Chave: quantum dots; zinc selenides; europium; manganese; zinc sulfides; biological functions; cell membranes; particle interactions

  • IPEN-DOC 28690

    REIS, T.A.; TRALAMAZZA, S.M.; COELHO, E.; ZORZETE, P.; FAVARO, D.I.T. ; CORREA, B.. Early expression of the aflatoxin gene cluster in Aspergillus nomiae isolated from Brazil nut. Toxicon, v. 209, p. 36-42, 2022. DOI: 10.1016/j.toxicon.2022.01.008

    Abstract: Aspergillus nomiae is the most important contaminant in Brazil nut due to its high incidence in these nuts and its strong production of carcinogenic metabolites: aflatoxins (AF). Aflatoxin biosynthesis pathway in A. nomiae is poorly studied. Thus, in present investigation, aflatoxin production and gene cluster (aflC, aflQ, aflU, and aflX) expression profile were evaluated on two strains of A. nomiae isolated from Brazil nut samples collected in the Amazon region, and cultivated on Brazil nut-based medium. The results showed that the expression of the aflatoxin gene cluster in A. nomiae, started at day 2 and occurred before the production of aflatoxins. Aflatoxin production (AFB1 and AFG1) was detected on day 3 on both strains. From day 4 onwards, all four toxins were detected and their production kept at similar proportions (AFG1>AFB1>AFG2>AFB2). Thus, the anticipated information obtained through early expression profile results of aflC, aflQ, aflU, and aflX gene cluster in A. nomiae may foresee aflatoxin production before its detection in Brazil nuts.

    Palavras-Chave: nuts; genes; aspergillus; aflatoxins; biosynthesis; gene regulation; mycotoxins

  • IPEN-DOC 23958

    QUEIROZ, F.M. ; TOMACHUK, C.R. ; ZUMELZU, E.; MELO, H.G. de; COSTA, I. . Effect of trivalent chromium based treatment on the protective properties of steel coated with polymeric film. ECS Transactions, v. 43, n. 1, 2012. DOI: 10.1149/1.4704937

    Abstract: Three main requirements are mandatory in order to achieve optimal quality in canned food: adequate processing of the product, definition of the preserving method, and a correct alloy for the deposit. Lacquer coatings are applied on food cans to enhance corrosion protection and also with decorative purposes. In this investigation, steel coated with a Cr3+ based treatment layer and polyethylene teraphtalate polymeric film (PET), applied by coextrusion, was characterized by electrochemical impedance spectroscopy (EIS) measurements, in NaCl 0.5 M solution, to evaluate the coating corrosion resistance in this environment. The experimental results showed that this new material (tin free) has good corrosion resistance regardless of the porosity found in the polymeric film, indicating that it can be a non-polluting alternative to replace tinplate and hexavalent chromium conversion layer in the food industry, being compatible with the packed product.

    Palavras-Chave: chromium compounds; polymers; films; polyethylene terephthalate; corrosion resistance

  • IPEN-DOC 28689

    RIBEIRO, LUCAS A.S. ; NEGRINI NETO, O. ; FREITAS, ANDERSON Z. de . Determinação de características mecânicas de folhas de papel utilizando a técnica de tomografia por coerência óptica, e suas aplicações na área forense / Determination of mechanical characteristics of sheets of paper using the optical coherence tomography technique and its applications in forensic sciences. Revista Brasileira de Ensino de Física, v. 44, p. e20210394-1 - e20210394-12, 2022. DOI: 10.1590/1806-9126-RBEF-2021-0394

    Abstract: Apresentamos nesse trabalho, uma metodologia para avaliar a pressão de punho durante o processo de escrita manual. Utilizando a tomografia por coerência óptica, foi possível determinar a deformação sofrida pelo papel durante o processo de escrita manual. Foi realizada uma calibração da deformação sofrida pelo papel em função da pressão exercida pela caneta, tornando possível determinar vários parâmetros de interesse, como por exemplo, o raio da esfera da ponta da caneta R = 488 ± 2μm, o coeficiente de Poisson ν = 0, 30 ± 0, 02 e o módulo de Young efetivo do papel sulfite 75 g/m2. Para tal, desenvolvemos um método de determinação do módulo de Hooke para uma mola, com a qual construímos um dispositivo para aplicação de uma força conhecida a uma caneta esferográfica durante o processo de escrita manual. Realizamos também o estudo em função do tipo de substrato, sendo que cinco voluntários tentaram copiar a mesma assinatura em quatro tipos diferentes de papel. Com o auxílio da técnica de tomografia por coerência óptica demonstramos que é possível diferenciar a autoria de uma assinatura também pela profundidade da deformação no papel. O procedimento experimental tornou possível ainda determinar o coeficiente de Poisson e determinar o Módulo de Young efetivo do papel.

    Palavras-Chave: surface tension; young modulus; hands; pressure range; poisson equation; strain rate

  • IPEN-DOC 28688

    PRADO, FELIPE M. ; UTIYAMA, KAREN A.U.; TOFFOLI, DANIEL J.; WETTER, NIKLAUS U. ; SILVA, SIDNEY L. da. Computational algorithm from the Huygens-Fresnel’s diffraction integral for two-dimensional holographic reconstruction. Revista Brasileira de Ensino de Física, v. 44, p. e20210193-1 - e20210193-4, 2022. DOI: 10.1590/1806-9126-RBEF-2021-0193

    Abstract: While most common holographic methods of digital reconstruction are based on the convolution theory, for the ease in the mathematical approach, here we present an algorithm by a discretization of the Huygens-Fresnel integral from a Taylor series expansion to produce a bidimensional Fourier transform. Compared to the digital convolution method, the algorithm presented here is more concise and generates a reduction in processing time, since the Fourier transform appears only once in the discretization. Another advantage is associated with the production of results in the frequency domain, allowing the optical information to be obtained directly.

    Palavras-Chave: computer codes; fresnel coefficient; holography; fourier transformation; digital systems; images

  • IPEN-DOC 28687

    MIRANDA, JURANDIR T. de; BRINGEL, FABIANA de A. ; VELOSA, ANA P.P.; PROTOCEVICH, VERONICA; FERNEZLIAN, SANDRA de M.; SILVA, PEDRO L.; CAPELOZZI, VERA L.; MATHOR, MONICA B. ; TEODORO, WALCY R.. Sterilized human skin graft with a dose of 25 kGy provides a privileged immune and collagen microenvironment in the adhesion of Nude mice wounds. PLoS One, v. 17, n. 1, p. 1-15, 2022. DOI: 10.1371/journal.pone.0262532

    Abstract: This study aimed to report the effects of different doses of ionizing radiation on inflammatory and repair stage of human skin graft adherence in Nude mice wounds. Animals were divided into transplanted with irradiated human skin grafts (IHSG) at 25 and 50 kGy (IHSG 25 kGy; IHSG 50 kGy) and non-IHSG and euthanized on the 3rd, 7th and 21st days after the surgery, by gross and microscopic changes, immunostaining for human type I collagen (Col I) and mouse Col I and Col III and inflammatory cells. We found an effectiveness of human split-thickness graft adherence in mice transplanted with IHSG 25 kGy, as well decrease in dermo-epidermal necrosis and neutrophils, lower loss of skin thickness, epithelization and neo-vascularization. Day 21 post-transplantation with IHSG 25 kGy was observed a well-preserved human skin in the border of the graft, a prominent granulation tissue in an organization by proliferated fibroblasts, Col III deposition and increased B-cells and macrophages. A complete adherence of human skin graft occurred with IHSG 25 kGy. We suggest that the ionizing radiation at 25 kGy mediates inflammation and the repair stage of human skin graft adherence in murine model, thus emerging as a potential tool in healing cutaneous wounds.

    Palavras-Chave: animal tissues; skin; grafts; ionizing radiations; radiation doses; immune reactions; collagen; wounds; burns

  • IPEN-DOC 28686

    CHURA-CHAMBI, ROSA M. ; PRIETO-DA-SILVA, ALVARO R. de B.; DI LELA, MATHEUS M. ; OLIVEIRA, JOAO E. ; ABREU, PATRICIA E.A.; MEIRELES, LUCIANA R.; ANDRADE JUNIOR, HEITOR F. de; MORGANTI, LIGIA . High level SARS-CoV-2 nucleocapsid refolding using mild condition for inclusion bodies solubilization: application of high pressure at pH 9.0. PLoS One, v. 17, n. 2, p. 1-14, 2022. DOI: 10.1371/journal.pone.0262591

    Abstract: SARS-CoV-2 Nucleocapsid (N) is the most abundant viral protein expressed in host samples and is an important antigen for diagnosis. N is a 45 kDa protein that does not present disulfide bonds. Intending to avoid non-specific binding of SARS-CoV-2 N to antibodies from patients who previously had different coronaviruses, a 35 kDa fragment of N was expressed without a conserved motif in E. coli as inclusion bodies (N122-419-IB). Culture media and IB washing conditions were chosen to obtain N122-419-IB with high yield (370 mg/L bacterial culture) and protein purity (90%). High pressure solubilizes protein aggregates by weakening hydrophobic and ionic interactions and alkaline pH promotes solubilization by electrostatic repulsion. The association of pH 9.0 and 2.4 kbar promoted efficient solubilization of N122-419-IB without loss of native-like tertiary structure that N presents in IB. N122-419 was refolded with a yield of 85% (326 mg/L culture) and 95% purity. The refolding process takes only 2 hours and the protein is ready for use after pH adjustment, avoiding the necessity of dialysis or purification. Antibody binding of COVID-19-positive patients sera to N122-419 was confirmed by Western blotting. ELISA using N122-419 is effective in distinguishing between sera presenting antibodies against SARS-CoV-2 from those who do not. To the best of our knowledge, the proposed condition for IB solubilization is one of the mildest described. It is possible that the refolding process can be extended to a wide range of proteins with high yields and purity, even those that are sensible to very alkaline pH.

    Palavras-Chave: coronaviruses; proteins; antibodies; enzyme immunoassay; pressure range mega pa 10-100

  • IPEN-DOC 28685

    MOSCA, RODRIGO C.; SANTOS, SOFIA N. dos ; NOGUEIRA, GESSE E.C. ; PEREIRA, DAISA L. ; COSTA, FRANCIELLI C. ; PEREIRA, JONATHAS X.; ZEITUNI, CARLOS A. ; ARANY, PRAVEEN R.. The efficacy of photobiomodulation therapy in improving tissue resilience and healing of radiation skin damage. Photonics, v. 9, n. 1, p. 1-13, 2022. DOI: 10.3390/photonics9010010

    Abstract: The increased precision, efficacy, and safety of radiation brachytherapy has tremendously improved its popularity in cancer care. However, an unfortunate side effect of this therapy involves localized skin damage and breakdown that are managed palliatively currently. This study was motivated by prior reports on the efficacy of photobiomodulation (PBM) therapy in improving tissue resilience and wound healing. We evaluated the efficacy of PBM therapy on 36 athymic mice with 125I seed (0.42 mCi) implantation over 60 days. PBM treatments were performed with either red (660 nm) or near-infrared (880 nm, NIR) LEDs irradiance of 40 mW/cm2, continuous wave, fluence of 20 J/cm2 once per week. Animals were evaluated every 7 days with digital imaging, laser Doppler flowmetry, thermal imaging, µPET-CT imaging using 18F-FDG, and histology. We observed that both PBM treatments—red and NIR—demonstrated significantly less incidence and severity and improved healing with skin radionecrosis. Radiation exposed tissues had improved functional parameters such as vascular perfusion, reduced inflammation, and metabolic derangement following PBM therapy. Histological analysis confirmed these observations with minimal damage and resolution in tissues exposed to radiation. To our knowledge, this is the first report on the successful use of PBM therapy for brachytherapy. The results from this study support future mechanistic lab studies and controlled human clinical studies to utilize this innovative therapy in managing side effects from radiation cancer treatments.

    Palavras-Chave: brachytherapy; modulation; radiations; wounds; light emitting diodes; formation damage; inflammation

  • IPEN-DOC 28684

    VIGATO, ARYANE A.; MACHADO, IAN P.; VALLE, MATHEUS del; ANA, PATRICIA A. da; SEPULVEDA, ANDERSON F.; YOKAICHIYA, FABIANO; FRANCO, MARGARETH K.K.D. ; LOIOLA, MESSIAS C.; TOFOLI, GIOVANA R.; CEREDA, CINTIA M.S.; SAIRRE, MIRELA I. de; ARAUJO, DANIELE R. de. Monoketonic curcuminoid-lidocaine co-deliver using thermosensitive organogels: from drug synthesis to epidermis structural studies. Pharmaceutics, v. 14, n. 2, p. 1-20, 2022. DOI: 10.3390/pharmaceutics14020293

    Abstract: Organogels (ORGs) are remarkable matrices due to their versatile chemical composition and straightforward preparation. This study proposes the development of ORGs as dual drug-carrier systems, considering the application of synthetic monoketonic curcuminoid (m-CUR) and lidocaine (LDC) to treat topical inflammatory lesions. The monoketone curcuminoid (m-CUR) was synthesized by using an innovative method via a NbCl5–acid catalysis. ORGs were prepared by associating an aqueous phase composed of Pluronic F127 and LDC hydrochloride with an organic phase comprising isopropyl myristate (IPM), soy lecithin (LEC), and the synthesized m-CUR. Physicochemical characterization was performed to evaluate the influence of the organic phase on the ORGs supramolecular organization, permeation profiles, cytotoxicity, and epidermis structural characteristics. The physico-chemical properties of the ORGs were shown to be strongly dependent on the oil phase constitution. Results revealed that the incorporation of LEC and m-CUR shifted the sol-gel transition temperature, and that the addition of LDC enhanced the rheological G′/G″ ratio to higher values compared to original ORGs. Consequently, highly structured gels lead to gradual and controlled LDC permeation profiles from the ORG formulations. Porcine ear skin epidermis was treated with ORGs and evaluated by infrared spectroscopy (FTIR), where the stratum corneum lipids were shown to transition from a hexagonal to a liquid crystal phase. Quantitative optical coherence tomography (OCT) analysis revealed that LEC and m-CUR additives modify skin structuring. Data from this study pointed ORGs as promising formulations for skin-delivery.

    Palavras-Chave: curcumin; gels; ketones; anesthetics; skin; inflammation

  • IPEN-DOC 28683

    VIEIRA, TARCIO de A. ; PRADO, FELIPE M. ; WETTER, NIKLAUS U. . Nd:YLF laser at 1053 nm diode side pumped at 863 nm with a near quantum-defect slope efficiency. Optics and Laser Technology, v. 149, p. 1-5, 2022. DOI: 10.1016/j.optlastec.2021.107818

    Abstract: Laser emission at the 1053 nm transition of Nd:YLF4 is demonstrated using diode-side-pumping at 863 nm directly into the emitting level. The laser configuration uses one total internal reflection at the pump face and provides the highest slope efficiency reported for the Nd:YLF4 medium, close to the quantum limit. In quasi-continuous mode, the laser operates with diffraction-limited beam quality and 78.2% slope efficiency with 14.4 W of output power. In continuous mode, 75.7% slope efficiency in both single-mode and multimode operation is achieved, with 13.5 W output power.

    Palavras-Chave: lasers; neodymium lasers; lithium fluorides; yttrium fluorides; crystal doping; optical pumping

  • IPEN-DOC 28682

    SILVA, FLAVIA R.O. ; LIMA, NELSON B. ; BELLINI, MARIA H. ; TEIXEIRA, LUIZ F.S. ; DU, ERIC Y.; JAMSHIDI, NILOUFAR; GOODING, JUSTIN; MARTIN, ADAM D.; MACMILLAN, ALEXANDER; MARQUIS, CHRISTOPHER P.; THORDARSON, PALL. Lanthanide-based β-tricalcium phosphate upconversion nanoparticles as an effective theranostic nonviral vectors for image-guided gene therapy. Nanotheranostics, v. 6, n. 3, p. 306-321, 2022. DOI: 10.7150/ntno.68789

    Abstract: Lanthanide-based beta-tricalcium phosphate (β-TCP) upconversion nanoparticles are exploited as a non-viral vector for imaging guided-gene therapy by virtue of their unique optical properties and multi-modality imaging ability, high transfection efficiency, high biocompatibility, dispersibility, simplicity of synthesis and surface modification. Ytterbium and thulium-doped β-TCP nanoparticles (βTCPYbTm) are synthesized via co-precipitation method, coated with polyethylenimine (PEI) and functionalized with a nuclear-targeting peptide (TAT). Further, in vitro studies revealed that the nanotheranostic carriers are able to transfect cells with the plasmid eGFP at a high efficiency, with approximately 60% of total cells producing the fluorescent green protein. The optimized protocol developed comprises the most efficient βTCPYbTm/PEI configuration, the amount and the order of assembly of βTCPYbTm:PEI, TAT, plasmid DNA and the culturing conditions. With having excellent dispersibility and high chemical affinity toward nucleic acid, calcium ions released from βTCPYbTm:PEI nanoparticles can participate in delivering nucleic acids and other therapeutic molecules, overcoming the nuclear barriers and improving the transfection efficacy. Equally important, the feasibility of the upconversion multifunctional nanovector to serve as an effective contrast agent for imaging modality, capable of converting low-energy light to higher-energy photons via a multi-photons mechanism, endowing greater unique luminescent properties, was successfully demonstrated.

    Palavras-Chave: gene therapy; polyethylenes; nanoparticles; calcium phosphates

  • IPEN-DOC 28681

    DAS, AVISHEK; RAPOSO, GISELE C.C.; LOPES, DANIELA S.; SILVA, EVAIR J. da; CARNEIRO, VANDA S.M.; MOTA, CLAUDIA C.B. de O.; AMARAL, MARCELLO M.; ZEZELL, DENISE M. ; BARBOSA-SILVA, RENATO; GOMES, ANDERSON S.L.. Exploiting nanomaterials for optical coherence tomography and photoacoustic imaging in nanodentistry. Nanomaterials, v. 12, n. 3, p. 1-22, 2022. DOI: 10.3390/nano12030506

    Abstract: There is already a societal awareness of the growing impact of nanoscience and nanotechnology, with nanomaterials (with at least one dimension less than 100 nm) now incorporated in items as diverse as mobile phones, clothes or dentifrices. In the healthcare area, nanoparticles of biocompatible materials have already been used for cancer treatment or bioimaging enhancement. Nanotechnology in dentistry, or nanodentistry, has already found some developments in dental nanomaterials for caries management, restorative dentistry and orthodontic adhesives. In this review, we present state-of-the-art scientific development in nanodentistry with an emphasis on two imaging techniques exploiting nanomaterials: optical coherence tomography (OCT) and photoacoustic imaging (PAI). Examples will be given using OCT with nanomaterials to enhance the acquired imaging, acting as optical clearing agents for OCT. A novel application of gold nanoparticles and nanorods for imaging enhancement of incipient occlusal caries using OCT will be described. Additionally, we will highlight how the OCT technique can be properly managed to provide imaging with spatial resolution down to 10′s–100′s nm resolution. For PAI, we will describe how new nanoparticles, namely TiN, prepared by femtosecond laser ablation, can be used in nanodentistry and will show photoacoustic microscopy and tomography images for such exogenous agents.

    Palavras-Chave: nanomaterials; dentistry; biological materials; photoacoustic effect; optics; optics; optics; tomography

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Ano de publicação: 2015

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Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).



O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.

2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.