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

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. Quimica Nova, v. 45, n. 6, p. 680-689, 2022. DOI: 10.21577/0100-4042.20170874. Disponível em: http://repositorio.ipen.br/handle/123456789/33229. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33227. Acesso em: $DATA.

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Abstract: Background: Modified citrus pectin (MCP) is a polysaccharide consisting of galacturonic acid with anti-cancer activity that can act synergistically with other treatments to reduce tumor growth, stimulate programmed cell death and reduce the number of metastases. In addition, MCP prevents acute and severe renal syndromes caused by radiation/chemotherapy. All of these effects were reported to be due to MCP ability to specifically inhibit Galectin-3 protein functions. Aims: The aim of this work was to evaluate the anticancer effect of MCP in a Balb/c nude mice xenograft model of ovarian cancer. Methods: The human ovary cancer cell line, SKOV-3, was subcutaneously injected in Balb/c nude mice and tumor growth was monitored daily with a caliper. When tumors reached 250-300 mm3, 20 mg/kl of MCP was administered intravenously (I.V.) in a daily based for 21 days. Tumor growth and mice weight were monitored daily. Additionally, MCP was radiolabeled with 99m-technetium (99m-Tc) with the incubation of MCP (2.5 mg) in saline with SnCl2 (4 mg/ ml), HCl (0.01 M), NaOH (0.01 M) and 99mTc (129,5 MBq) at pH=7 for 30 min. The radiochemical purity was determined by iTLC-SG with acetone and ethanol/NH3/H2O (1:2:5). 99mTc-MCP (37 MBq) was administrated I.V. in Balb/C nude mice bearing SKOV-3 tumors and after 1, 2 and 4 hours, SPECT/CT image was acquired (Albira SI Buker). Ex-vivo biodistribution studies were performed after the I.V. injection of 10 MBq of 99mTc-MCP for 1-hour. The % of injected dose per gram (%ID/g) of tissues of interest was calculated. The tumors were removed, fixed, cut and used for autoradiography studies and stained with hematoxylin and eosin (H&E) to verify hypoxic regions. Results: The I.V. administration of MCP was able to significantly reduce SKOV-3 tumor growth (52% tumor volume reduction) in comparison with the non-treated group, after 21 of treatment. Our biodistribution studies showed that 99mTc-MCP was mainly found in kidneys, bladder and liver of mice (%ID/g = 12.25, 38.57 and 5.71, respectively), and was able to reach the tumor (%ID/g = 0.765 ± 0.045) 1-hour after I.V. administration. 99mTc-MCP accumulation in the tumor site was visualized by μSPECT/CT imaging 1 hour after I.V. administration. The autoradiography and stained (H&E) study demonstrated a correlation between MCP and regions of tumor necrosis. Because of MCP high accumulation in kidneys, renal toxicity was also evaluated. We were able to find that MCP doesn’t induce renal toxicity when administered in a daily base at a concentration of 20 mg/Kg. Conclusion: In this work we demonstrated that a daily treatment of MCP was able to reduce tumor growth of ovarian tumor xenografts (SKOV-3 cells) without showing renal toxicity. We found too that MCP can reach the tumor site, binding mainly in regions of necrosis. However, other studies are needed to unravel the mechanisms of action that act on the antitumor effect of MCP.

SILVA, FABIO A. da; BERNARDES, EMERSON S. Uncovering the role of modified citrus pectin in cancer. Nuclear Medicine and Biology, v. 108-109, p. S176-S177, 2022. S1, DOI: 10.1016/S0969-8051(22)00371-7. Disponível em: http://repositorio.ipen.br/handle/123456789/33225. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33223. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33221. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33219. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33217. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33215. Acesso em: $DATA.

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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

BOTOSSO, VIVIANE F.; JORGE, SORAIA A.C.; ASTRAY, RENATO M.; GUIMARAES, ANA M. de S.; MATHOR, MONICA B.; CARNEIRO, PATRICIA dos S. de; DURIGON, EDISON L.; COVAS, DIMAS; OLIVEIRA, DANIELLE B.L. de; OLIVEIRA, RICARDO das N.; MARIA, DURVANEI A.; ETO, SILAS F.; GALLINA, NEUZA M.F.; PIDDE, GISELLE; SQUAIELLA‑BAPTISTAO, CARLA C.; SILVA, DILZA T.; VILLAS‑BOAS, ISADORA M.; FERNANDES, DAYANNE C.; AUADA, ALINE V.V.; BANARI, ALEXANDRE C.; SOUZA FILHO, ANTONIO F. de; BIANCONI, CAMILA; UTESCHER, CARLA L. de A.; OLIVEIRA, DENISE C.A.; MARIANO, DOUGLAS O.C.; BARBOSA, FLAVIA F.; RONDON, GIULIANA; KAPRONEZAI, JOSANA; SILVA, JULIANA G. da; GOLDFEDER, MAURICIO B.; COMONE, PRISCILA; CASTILHO JUNIOR, REGIS E.; PEREIRA, TAIANA T.S.; WEN, FAN H.; TAMBOURGI, DENISE V.; CHUDZINSKI‑TAVASSI, ANA M. Anti‑SARS‑CoV‑2 equine F (Ab′)2 immunoglobulin as a possible therapy for COVID‑19. Scientific Reports, v. 12, p. 1-17, 2022. DOI: 10.1038/s41598-022-07793-1. Disponível em: http://repositorio.ipen.br/handle/123456789/33213. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33211. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33209. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33207. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33205. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33203. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33201. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33199. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33197. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33195. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33193. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33191. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33189. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33187. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33177. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33175. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33173. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33171. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33169. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33167. Acesso em: $DATA.

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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

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. Brazilian Journal of Development, v. 8, n. 3, p. 17576-17588, 2022. DOI: 10.34117/bjdv8n3-139. Disponível em: http://repositorio.ipen.br/handle/123456789/33165. Acesso em: $DATA.

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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

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. Brazilian Journal of Development, v. 8, n. 4, p. 31731-31738, 2022. DOI: 10.34117/bjdv8n4-586. Disponível em: http://repositorio.ipen.br/handle/123456789/33163. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33161. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33159. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33157. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33155. Acesso em: $DATA.

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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

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. Disponível em: http://repositorio.ipen.br/handle/123456789/33153. Acesso em: $DATA.

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