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URI Permanente para esta coleçãohttps://repositorio.ipen.br/handle/123456789/3977

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Thermoluminescence, electron paramagnetic resonance, and structural characterization of natural prehnite for high-dose radiation dosimetry
2026 - GOMES, MONISE B.; GONZALES-LORENZO, CARLOS D.; ROCCA, RENE R.; RAMIREZ, F. N.; CUEVAS-ARIZACA, EDY E.; SILVA-CARRERA, BETZABEL N.; GUNDU RAO, T. K.; CANO, NILO F.; CHUBACI, JOSE F. D.
Natural prehnite was evaluated as a thermoluminescence (TL) material for high-dose dosimetry. XRF identified SiO₂, Al₂O₃, and CaO as major constituents. Prehnite samples annealed between 200 and 800 °C (1 h) were examined by XRD and Rietveld analysis, confirming prehnite as the majority phase and revealing calcite and vaterite after heating. The 600 °C sample provided the highest TL yield and was selected for detailed study. Fading tests showed a ~40% loss in the 240 and 350 °C peaks over 5.42 days (130 h), followed by signal stability. Dose–response demonstrated, for the 245 °C peak and 325 °C peak, linear regions in the ranges of 0.1–2 kGy and 0.5–20 kGy, respectively, with saturation occurring between 30 and 100 kGy. Kinetic parameters were obtained using TM-Tstop, initial-rise, and variable-heating-rate methods; glow-curve deconvolution resolved five TL components. TL spectra displayed an intense band near 530 nm and a weak band at 550 nm, suggesting two main recombination centers.
Thermodynamic integration of HTGR nuclear heat into the Barrancabermeja refinery
2026 - ENCISO, NICOLAS; MORALES, DANIEL
Decarbonizing refinery process heat and hydrogen production remains a major challenge for industrial net-zero pathways. High-temperature gas-cooled small modular reactors (HTGR–SMRs) are promising candidates because they combine high outlet temperatures, modular deployment, and inherent safety. This work develops a unified thermodynamic–exergy framework based on Pinch Point analysis, differential heat-transfer integration, and entropy-generation balances to assess HTGR coupling with refinery heat, hydrogen, and cogeneration systems under realistic industrial conditions. Results show that the main thermodynamic difference among the evaluated configurations is not the presence of the Once-Through Steam Generator (OTSG) itself, but the thermal matching between the nuclear heat source and refinery demands. Indirect steam delivery through an OTSG and direct helium supply to multiple refinery processes achieve comparable refinery-level performance, with second-law efficiencies of approximately 62.57%. In contrast, direct helium supply to the topping process—one of the most critical units in the refinery—reaches a lower efficiency of about 57.5%, corresponding to a relative improvement of approximately 8.8% for the OTSG and multi-process configurations. This indicates that, although direct helium exchange preserves a higher temperature potential, it suffers from greater thermal mismatch and higher irreversibility at the reactor–process interface, particularly when applied to single high-demand units such as topping. Applied to the Barrancabermeja Refinery, the proposed architecture could supply about 400 MWth of process heat while supporting cogeneration, low-carbon hydrogen pathways, and avoiding on the order of 3 Mt CO₂/year.
Analysis of the influence of geometric parameters of laser-produced texturing on carbide tools in Ti6Al4V turning
2026 - SOUZA, FELIPE C. R. de; PAULA, FABIO R. de; MACHADO, ALISSON R.; ROSSI, WAGNER de
This study focuses on analyzing the influence of different groove texture geometries on carbide cutting tools for turning Ti6Al4V titanium alloy, exploring how different parameters (depth, width, spacing, direction, and distance from the cutting edge) affect machining performance. This work contributes to the advancement of machining techniques, promoting more efficient and sustainable processes, with potential practical applications in industry. The objectives include reducing machining forces while minimizing machining costs. The methodology employed advanced technologies, such as femtosecond lasers, to produce defect-free textures without thermal damage or microcracks. Initial results demonstrated that textured tools can significantly improve the machining process by reducing machining forces. The results showed that texture direction and distance from the cutting edge were the most influential parameters, while texture dimensions had a lesser impact. Furthermore, the effects of textures were found to vary with feed rate, highlighting the need for specific optimizations for different cutting regimes (such as roughing or finishing).
Climatechain e o monitoramento de incidentes ambientais e estruturais em cenários de mudanças climáticas
2025 - OLIVEIRA, ISRAEL A.M.; COSTA, ISABELA B. da; ANDRANDE, ANA B.B. de; RIBEIRO, GEOVANA F.; PRAGA, LARA J.R.; GRESPAN, PAULO R.G.; FUNGARO, DENISE A.
Diante do crescente impacto das mudanças climáticas e da frequência de incidentes ambientais em áreas urbanas, soluções inovadoras e integradas são urgentes. O ClimateChain foi elaborado como uma resposta prática para monitorar e alertar, em tempo real, sobre incêndios, vazamentos de água e falhas energéticas no município de Marília-SP, garantindo ações rápidas e eficazes. A principal contribuição do projeto está na combinação de tecnologia e de participação popular. Na área de tecnologia, os sensores ambientais, APIs (do Inglês Application Programming Interfaces),de clima e imagens de satélite fornecem dados precisos. Em relação à participição popular, uma plataforma digital aberta à população permite que moradores reportem problemas, criando uma rede de informações colaborativa. A pesquisa bibliográfica e o desenvolvimento do site foram realizados a partir de dados coletados em artigos entre 2015 e 2025 (Google Acadêmico, SciELO) e registros locais. Os resultados obtidos demonstraram os seguintes fatos: (a) o sistema reduziu o tempo de resposta à emergências, evitando maiores danos e otimizando recursos municipais; (b) a transparência gerada pela plataforma aumentou a confiança da população nas ações governamentais.Pode-se concluir que o ClimateChain vai além de uma ferramenta técnica, sendo um exemplo de como a colaboração entre engajamento social e inovação podem impulsionar a construção de cidades mais resilientes. O projeto contribui com os Objetivos do Desenvolvimento Sustentável, especialmente, ODS 11 (Cidades e Comunidades Sustentáveis), com a participação cidadã e o uso de tecnologias para enfrentar desafios ambientais urbanos.
Unveiling the role of rhenium precursors in supercritical CO2 hydrogenation
2025 - MACHADO, FELIPE; GOTHE, MAITE L.; BORGES, LAIS R.; PORTES, MARCELO C.; RODRIGUES, ORLANDO; ANDO, ROMULO A.; ROSSI, LIANE M.; VIDINHA, PEDRO
Heterogeneous rhenium catalysts supported on various oxides, particularly TiO2, have demonstrated effectiveness in converting carbon dioxide (CO2) to methanol via hydrogenation, showing high selectivity under diverse reaction conditions. However, the impact of different rhenium precursors on the catalytic performance and physicochemical properties of ReOx/TiO2 has not yet been elucidated. Herein, we compared catalysts prepared from NH4ReO4 and Re2O7 precursors with varying rhenium content (4–14 wt% Re) synthesized using a wet impregnation approach. These catalysts were evaluated under different reaction temperatures (200–250 °C), pressures (100–200 bar), and H2/CO2 ratios (1–4). This study revealed that both catalytic performance and physicochemical properties varied not only with the type of precursor but also with the rhenium content. Variation in reduction temperature, particle size, oxidation states of Re and surface Re═O terminals were observed. In batch system, catalysts derived from NH4ReO4 demonstrated a higher selectivity for methanol production under high pressure and stoichiometric conditions, regardless of temperature. In contrast, Re₂O₇-based catalysts demonstrated higher methanol selectivity at 200 °C, with H₂/CO₂ ratios between 1 and 3, regardless of the total pressure. These findings provide a deeper and valuable insight on the choice of precursors for the preparation of ReOx/TiO2 catalysts for CO2 hydrogenation.
In silico dosimetry for a prostate cancer treatment using 198Au nanoparticles
2025 - ANGELOCCI, LUCAS V.; SPRIGNOLI, SABRINA S.; SOUZA, CARLA D. de; ANTUNES, PAULA C.G.; ROSTELATO, MARIA E. C. M.; ZEITUNI, CARLOS A.
Objective. To estimate dose rates delivered by using radioactive 198Au nanoparticles for prostate cancer nanobrachytherapy, identifying contribution by photons and electrons emmited from the source. Approach. Utilizing in silico models, two different anatomical representations were compared: a mathematical model and a unstructured mesh model based on the International Commission on Radiological Protection (ICRP) Publication 145 phantom. Dose rates by activity were calculated to the tumor and nearby healthy tissues, including healthy prostate tissue, urinary bladder wall and rectum, using Monte Carlo code MCNP6.2. Main results. Results indicate that both models provide dose rate estimates within the same order of magnitude, with the mathematical model overestimating doses to the prostate and bladder by approximately 20% compared to the unstructured mesh model. The discrepancies for the tumor and rectum were below 4%. Photons emmited from the source were defined as the primary contributors to dose to other organs, while 97.9% of the dose to the tumor was due to electrons emmited from the source. Significance. Our findings emphasize the importance of model selection in dosimetry, particularly the advantages of using realistic anatomical phantoms for accurate dose calculations. The study demonstrates the feasibility and effectiveness of 198Au nanoparticles in achieving high dose concentrations in tumor regions while minimizing exposure to surrounding healthy tissues. Beta emissions were found to be predominantly responsible for tumor dose delivery, reinforcing the potential of 198Au nanoparticles in localized radiation therapy. We advocate for using realistic body phantoms in further research to enhance reliability in dosimetry for nanobrachytherapy, as the field still lacks dedicated protocols.
Revealing microplastic and anthropogenic microparticles contamination in tidal blue carbon ecosystems from eastern Brazil
2026 - ZANETTI, DANIELA G.; GOMES, LUIZ E. de O.; GOMES, MITCHAEL M. S.; ARAUJO, EDUARDO N. D. de; BARIZAO, ANA C. de L.; BATISTA, ANDERSON A.; DIPOLD, JESSICA; WETTER, NIKLAUS U.; BOM, FABIO C.; FREITAS, ANDERSON Z. de; SA, FABIAN
We provide information about the accumulation of microplastic and other anthropogenic microparticles (AMP) in tidal blue carbon ecosystems from Eastern Brazil. This study analyzed the accumulation of AMP in 40 sediment samples extracted from tropical Spartina marshes (2 cores: CM1 and CM2) and mangroves (1 core: CAB) from Todos os Santos Bay (TSB, Bahia, Brazil). The main objective was to identify differences in AMP accumulation between mangrove and Spartina salt marsh cores in order to understand their different roles in AMP retention and evaluate whether Spartina marshes act as stronger AMP sinks than mangroves. The average AMP abundance was at least 38% higher in salt marshes compared to mangroves. Micro-Raman spectroscopy was applied to determine the chemical composition of the different collected samples, thereby enabling a detailed investigation of their structural and compositional features. Fibers represented the dominant category, likely due to the widespread use of synthetic fibers, insufficient wastewater treatment, and high levels of fishing activities in the area. The predominant colors in all cores were blue (41.6%) and transparent (20.0%), and the predominant particle size was between 0 and 1 mm. Organic matter (%OM) and mud content (%M) did not influence AMP concentration. This work improves the understanding of the distribution and consequences of AMP in South American mangrove and salt marsh ecosystems, highlighting the need for collective and comprehensive efforts to mitigate their effects, such as improving the efficiency of wastewater management and addressing other human uses and mismanagement in TSB.
Gamma irradiation-induced degradation of organochlorine pesticides
2026 - VIEIRA, ANA C. D.; VASQUEZ, PABLO A. S.; OLIVEIRA, MARIA J. A. de; WANDERMUREN, MARCIO N.; CRISTALE, JOYCE
The presence of pesticide residues in cultural heritage collections poses health risks to museum professionals, making mitigation essential. This study evaluates gamma radiation as a decontamination strategy through two complementary experiments. Standard solutions of organochlorine pesticides (dichlorodiphenyltrichloroethane, hexachlorobenzene, and lindane) were irradiated to assess degradation, while model materials (cotton, wood, vegetable fiber, and feathers) were artificially contaminated and irradiated with 30 kGy. Analyses by gas chromatography–mass spectrometry, Fourier-transform infrared spectroscopy, colorimetry, and scanning electron microscopy demonstrated pesticide degradation without significant chemical, chromatic, or structural alterations, highlighting ionizing radiation as a promising method for decontaminating cultural heritage materials.
Plano de amostragem e vigilância de agrotóxicos em água tratada no estado de São Paulo, Brasil
2026 - VEIGA, DENISE P. B. da; NAKANO, VIVIANE E.; PEDRON, CIBELE N.; ALABURDA, JANETE; KIMURA, IRACEMA de A.; BUGNO, ADRIANA; BUSTILLOS, JOSE O. W. V.; MARIO JUNIOR, RUBENS J.; SANTOS, GEYSE A. C. dos; VALENTIM, LUIS S. O.
O Brasil é líder mundial no consumo de agrotóxicos, conforme relatório da Organização das Nações Unidas para Alimentação e Agricultura (FAO). O controle e a vigilância da água para consumo humano desses contaminantes envolvem responsabilidades dos prestadores de serviços de saneamento e dos órgãos de Vigilância do Sistema Único de Saúde (SUS). O objetivo foi descrever o plano de amostragem de vigilância e os resultados do monitoramento de agrotóxicos em água para consumo humano no estado de São Paulo. De 2020 a 2023, foram selecionados 137 municípios para análise de 91 agrotóxicos, utilizando a técnica de cromatografia líquida associada à espectrometria de massas. A seleção considerou: atividade agrícola no entorno das captações dos sistemas de abastecimento de água, população abastecida, histórico de resíduos em água e alimentos, maior área agrícola, estabelecimentos agrícolas que utilizam agrotóxicos e número de intoxicações exógenas. Todas as amostras apresentaram resultados abaixo dos estabelecidos na Portaria GM/MS 888/2021. Foram detectados com maior frequência no período chuvoso: 2,4-D, Diuron, Tebuconazol, Bentazona e Atrazina. Verificou-se a importância de o monitoramento de vigilância considerar a caracterização do território para definição de período oportuno de coleta.
Development and characterization of a W8Ni3Cu alloy for gamma radiation shielding
2025 - SOUZA, ARMANDO C.; ARISTONE, FLAVIO; CORTEZ, MARCO A. A.; LLIMA, MUNIQUE S. de; PORTO, DUILIO R.; SILVA, RAFAELA M. da; ROSSI, JESUALDO L.
This study investigates the potential of a W8Ni3Cu alloy as a gamma radiation shielding material for transporting highly radioactive substances. The alloy, composed of tungsten (W), nickel (Ni), and copper (Cu), was characterized using X-ray diffraction after sintering, revealing a body-centered-cubic crystal structure with an α-tungsten phase and a secondary γ-nickel-tungsten (Ni17W3) phase. The gamma radiation attenuation coefficients of the alloy were measured using a 60Co source. The results showed linear attenuation coefficients of 0.688 cm-1 for the alloy sintered at 1200°C and 0.488 cm-1 for the alloy sintered at 1300°C. These values are 34% and 53% lower than the reference value of pure tungsten (1.044 cm-1), but they still demonstrate adequate shielding properties for practical use. The findings suggest that the W8Ni3Cu alloy is a promising candidate for fabricating containers for the safe transport of radioactive material.
Application of gamma irradiation for the decontamination of historical glass plate photographic negatives
2026 - NAGAI, MARIA L. E.; SOMESSARI, ELIZABETH S. R.; REIS, TATIANA A.; VASQUEZ, PABLO A. S.
Ionizing radiation is an effective method for fungal decontamination of photographic heritage materials; however, its application to glass plate negatives may induce optical darkening due to radiation-induced defects in the glass matrix. This study investigates the influence of temperature during gamma irradiation and the potential of UVB light exposure as a non-thermal bleaching strategy. Historical glass plate negatives were irradiated at 6 kGy under room temperature and dry-ice cooling, while common soda–lime–silica glass samples were used as analogues to quantify optical changes. Low-temperature processing mitigated color alterations without affecting decontamination efficacy, whereas UVB exposure promoted partial recovery of transparency in a dose-dependent manner. The combined approach offers a viable strategy for balancing biocidal effectiveness and optical preservation in glass-based photographic heritage.
One-nucleon transfer reactions in the 20 Ne + 76 Ge system at 𝐸lab=15.3MeV/u
2025 - LINARES, R.; CARDOZO, E. N.; ZAGATTO, V. A. B.; CAPPUZZELLO, F.; CARBONE, D.; CAVALLARO, M.; ACOSTA, L.; AGODI, C.; BOZTOSUN, I.; CALVO, E. R.; CHAVEZ LOMELI, D.; CIRALDO, I.; DELAUNAY, F.; FERREIRA, J.; FISICHELLA, M.; GAROFALO, C.; HACISALIHOGLU, A.; LA FAUCI, L.; LOMBARDO, C.; LUBIAN, J.; MORALLES, M.; OLIVEIRA, J. R. B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PITRONACI, A.; SGOUROS, O.; SOLAKCI, S. O.; SOUKERAS, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; YILDIRIM, A.
Background: The nuclear matrix element (NME) is an important quantity in studies of the neutrinoless double beta (0 nu beta beta) decay, for which the 76Ge nucleus is one of the candidate isotopes for direct searches. The NME might be experimentally constrained by heavy-ion double charge exchange (HI-DCE) reaction at relevant energies. However feasibility of the HI-DCE as a tool for the NME requires accurate analyses of the competing multisteps one-nucleon transfers that connects the same initial and final mass partitions. Purpose: In this work we present the one-proton stripping and one-neutron pickup reactions in the 20Ne + 76Ge system measured at 15.3 MeV/u. These one-nucleon transfer reactions are used to benchmark the direct reaction and nuclear structure models that will be used to compute the contribution of multinucleon transfers competing with the HI-DCE. Methods: Experimental data of differential cross sections are compared with coupled reaction channel calculations using spectroscopic amplitudes as obtained from large-scale shell model. The validity of model space and interactions adopted to describe the target and the targetlike nuclei are further checked against (d,p) and (3He,d) data available in the literature. Results: We obtain an overall good description of experimental data for the one-proton stripping and one-neutron pickup transfer in the 20Ne+ 76Ge reactions. We also reproduce the behavior of the cross sections for channels in the 76Ge(3He,d) 77As and the 76Ge(p,d) 75Ge data. Conclusions: The result obtained in this work fills some intermediate one-nucleon transfer steps in the intricate multitransfer paths that compete with the direct meson exchange mechanism for the heavy-ion double charge exchange.
Multigroup energy representation for fast Monte Carlo estimation of radioisotope yields from electron-beam spectra
2026 - NUNES, BRUNO S.; VIEIRA JUNIOR, NILSON D.; BONATTO, ALEXANDRE; SAMAD, RICARDO E.
Monte Carlo (MC) simulations are widely used to estimate radioisotope production through nuclear reactions. However, achieving high accuracy typically requires simulating more than 10^8 particles, which is computationally demanding, particularly when many simulations are required, such as in optimization loops. In a previous study, we demonstrated that molybdenum-99 yields from bremsstrahlung-driven photonuclear reactions induced by laser-accelerated electron beams can be estimated up to four orders of magnitude faster by employing a multigroup energy representation, in which a limited set of MC precomputed group yields is used to reconstruct the total yield for an arbitrary source spectrum. This work expands this approach by showing that the multigroup representation also provides a deeper understanding of the relative contribution of different electron energies to the final isotope yield. Applying the method to 640 different spectra revealed how the choice of group structure—such as the number of groups and their energy widths—affects both accuracy and efficiency. The results show that the proposed approach reproduces full MC yield estimates with median errors below 5%, reaching values as low as 0.3%.
Porphyrin-coated gold nanoparticles associated with X-rays and proton therapy in the treatment of triple-negative breast cancer
2026 - SILVA, CAMILA R.; HEUSKIN, ANNE-CATHERINE; BERIONNI, GUILLAUME; RIBEIRO, MARTHA S.
Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer, known for its marked resistance to radiotherapy. Recent research has focused on developing innovative therapeutic strategies to overcome this challenge, with one promising approach being the combination of photodynamic therapy (PDT) and radiotherapy (RT). However, the potential of nanoparticles loaded with photosensitizers to enhance therapeutic efficacy, particularly in combination with charged particle therapies, such as proton therapy (PT), remains underexplored. In this study, we developed porphyrin-coated gold nanoparticles (AuNPs@TMPyP) to integrate PDT with RT using both photons and protons. PDT was performed using AuNPs@TMPyP (35 mg mL−1 gold content and 25 mM TMPyP) activated by a red laser (fluence: 40 J cm−2) and combined with either X-rays (225 kVp) or PT (10 keV mm−1). The combined treatment was evaluated for its effects on singlet oxygen generation, reactive oxygen species (ROS) production, mitochondrial membrane potential, and cell death pathways. Additionally, we assessed the survival fraction of both healthy and tumor breast cells. A 3D spheroid model was employed to further investigate the efficacy of the AuNPs@TMPyP-mediated PDT in combination with RT. Intracellular uptake of AuNPs@TMPyP significantly impaired antioxidant defenses through reduction of thioredoxin reductase levels. Under combined treatment, we observed increased ROS production, reduced survival fraction, and loss of mitochondrial membrane potential, along with increased apoptosis. Our findings suggest that AuNPs@TMPyP-mediated PDT significantly enhances radiosensitization and amplifies the therapeutic response when combined with either X-rays or PT, while exhibiting selectivity toward tumor cells, positioning it as a promising strategy for treating TNBC.
The effect of gamma-irradiated recycled polyolefins as asphalt binder modifier
2025 - PINHEIROS, GUSTAVO; DIPOLD, JESSICA; FREITAS, ANDERSON Z.; VASCONCELOS, KAMILA; WETTER, NIKLAUS
The current study evaluated the potential effects on the rheological properties of an asphalt binder modified with two recycled postconsumer polyolefins, polyethylene (PE) and polypropylene (PP), both with and without exposure to gamma-ray (γ-ray) irradiation, putting out a procedure that ensures benefits concerning the behavior and performance of asphalt pavements. The chosen analytical methods intend to investigate: the polyolefins’ chemical and physicochemical properties; the asphalt binders’ linear viscoelastic behaviour and damage characteristics; and the high-temperature storage stability. The results demonstrated: significant changes in the molecular structure of irradiated polyolefins, as well as the presence of contaminants in one of the recycled plastics; improvements in the rheological behaviour of the modified binders, showing better results performed after irradiated-polyolefins addition, with gains in rutting and fatigue cracking resistance; high separation tendency of polyolefins from asphalt binder matrix was observed, even for γ-ray exposure polymers.
Urban river microplastics as vectors for pharmaceutical contaminants in a savannah region (Caatinga biome)
2026 - SANTOS, YANNICE T. da C.; FERREIRA, ANDERSON T. da S.; MARTINS, LYNDYANNE D.; SOUSA, HELLEN da S.; KUZNETSOVA, MARIA; FAUSTINO, FRANCISCO W.; RIBEIRO, MARIA C. H.; FREITAS, ANDERSON Z. de; WETTER, NIKLAUS U.
The study investigates the presence of emerging contaminants in a river within a watershed located in the Brazilian semiarid region, specifically within the Caatinga biome, emphasizing the importance of environmental monitoring in areas that have historically been underrepresented in scientific research. The analysis focused on the associations between microplastics and pharmaceutical compounds, demonstrating that the discharge of untreated domestic effluents and the low efficiency of sanitation systems increase water resource contamination and threaten water security. The interdependence between these variables underscores the need for integrated public policies for waste management, complemented by environmental education strategies and technological innovations. The work makes an unprecedented contribution to expanding knowledge about emerging pollutants in semiarid environments, highlighting the urgency of holistic approaches, continuous monitoring, and strengthening environmental governance to ensure the sustainability and resilience of ecosystems like the Caatinga in the face of the challenges posed by global environmental change, urban growth, and those outlined in the Sustainable Development Goals.
Synthesis of Arapaima gigas growth hormone (ag-GH) in HEK 293 cells
2026 - LIMA, ELIANA R.; MELO, JENIFFER C. R.; BEZERRA, FILIPE M.; SUZUKI, MIRIAM F.; NUNES, AMANDA P.; SEVILHANO, THAIS C. dos A.; OLIVEIRA, JOAO E.; GARCEZ, RIVIANE; TORATI, LUCAS S.; MAGALHAES, GERALDO S.; PERONI, CIBELE N.; BARTOLINI, PAOLO
Arapaima gigas growth hormone (ag-GH) cDNA was previously cloned from A. gigas pituitaries. In this work ag-GH has been synthesized using human embryonic kidney 293 cells (HEK293) transiently transfected with the 3.4-TOPO® vector carrying ag-GH cDNA. The 4th day after transfection, the presence of putative ag-GH was detected via SDS-PAGE and Western blotting in comparison with human GH. Ion exchange purification exhibited a clearly symmetric peak, absent in the control medium. The purified fraction, submitted to high-performance size-exclusion chromatography (HPSEC), SDS-PAGE, and Western blotting, contained an immunoreactive molecule, slightly smaller than hGH as expected. MALDI-TOF-MS determined a high-resolution molecular mass of 21,220 Da versus a theoretical value of 21,150. A phylogenetic analysis positioned ag-GH within basal teleost lineages, consistent with earlier analyses of A. gigas gonadotrophic hormones, reinforcing the structural and functional conservation relevant for its biologic activity. An in vivo bioassay based on the body weight increase of dwarf “little” mice demonstrated a biological activity for ag-GH comparable to that of the international reference preparation of rec-hGH. For two species (H. sapiens and A. gigas) separated by an evolutionary period of >100 million years, such a positive biological correlation is remarkable.
Investigation of antitumor activity of modified citrus pectin
2026 - SILVA, FABIO F. A. da; SANTOS, SOFIA N. dos; PEDROSA, LUCAS de F.; RODRIGUES, VINICIUS G.; PEREIRA, JONATHAS X.; PEREIRA, JHONATAS P. M.; GUSHIKEN JUNIOR, DINO S.; ROSALES, THIECLA K. O.; DIAS, LUIS A. P.; SPENCER, PATRICK J.; FABI, JOAO P.; BERNARDES, EMERSON S.
This study employed molecular imaging to evaluate MCP (PectaSol-C, modified citrus pectin, a complex polysaccharide with antitumor potential) absorption and pharmacokinetics following oral and intravenous (IV) administration. MCP was radiolabeled with technetium-99m (99mTc) ([99mTc]MCP), allowing precise in vivo tracking. Imaging and biodistribution analyzes revealed low tumor uptake of IV [99mTc]MCP, with predominant renal and hepatobiliary clearance. Within tumors, MCP was detected at low levels and did not bind to viable cells. Consistent with these findings, IV administration produced only modest antitumor effects (∼50% tumor growth reduction) in SKOV-3 (ovarian), MKN45 (gastric), and 4T1 (breast) grafts, whereas oral administration was ineffective due to extremely poor absorption (bioavailability <0.01%). Notably, faster clearance of [99mTc]MCP in galectin-3 (Gal-3) knockout mice suggests a role for Gal-3 in systemic retention or an indirect contribution to antitumor activity. These findings provide new insights into MCP pharmacological profile, highlight the limitations of oral delivery, and underscore the need for improved delivery strategies to enhance the therapeutic potential of pectin-based cancer treatments.
Conserved enzymatic peptides in Bitis arietans venom revealed by comparative proteomics
2026 - GODOI, KEMILY S. de; PORTARO, FERNANDA C. V.; SPENCER, PATRICK J.; VIGERELLI, HUGO; SILVA, WILMAR D. da
Snakebite envenoming remains a critical public health issue, and the molecular variability of venoms limits the cross-species efficacy of conventional antivenoms. Here, we conducted a comparative proteomic analysis of Bitis arietans venom to identify conserved peptide regions derived from enzymatic toxins and evaluate their potential relevance for complementary immunotherapeutic applications. Enzyme-enriched venom fractions were isolated through sequential affinity and ion-exchange chromatography and were subsequently characterized using fluorogenic FRET substrates and inhibitor assays. LC–MS/MS analysis identified 1099 proteins and revealed 36 conserved peptides within snake venom metalloproteinases (SVMPs), serine proteases (SVSPs), and phospholipase A2 (PLA2), particularly located near catalytic residues and structurally essential motifs such as the HExxHxxGxxH zinc-binding site in SVMPs, the His-Asp-Ser catalytic triad in SVSPs, and the Ca2+-binding loop in PLA2, across Viperidae venoms. These conserved regions were also observed in homologous toxin isoforms from additional Viperidae genera, supporting the evolutionary conservation of key functional domains. While sequence conservation alone does not guarantee neutralization capacity, the identified regions represent strong candidates for structural epitope mapping and targeted antibody development. This study provides a peptide-level framework for advancing complementary antibody-based therapies designed to broaden cross-species toxin recognition, reduce antivenom dosage requirements, and improve clinical outcomes in snakebite envenoming.
Electrodeposition of CoCrFeNiAl high-entropy alloy coatings
2026 - FOGASSA, FERNANDA S.; PILLIS, MARINA F.; TRIVENO RIOS, CARLOS; ANTUNES, RENATO A.; OLIVEIRA, MARA C. L. de
In this work, CoCrFeNiAl high-entropy alloy coatings were obtained by electrodeposition in aqueous solution, using 1020 carbon steel plates as substrates. The effect of the deposition time on corrosion resistance of the coated samples was evaluated. Four deposition times were tested: 15, 20, 25, and 30 min. The corrosion behavior was studied in 3.5 wt.% NaCl solution using electrochemical impedance spectroscopy and potentiodynamic polarization tests. The corrosion protection ability was dependent on the plating time. The coated samples exhibited passive corrosion behavior, while the uncoated steel substrate was in an active state. The stability of the passive film was higher at deposition times of 15 min and 20 min. The passive range for the specimens obtained at a deposition time of 15 min was 3.7 times wider than at 30 min. The improved passive film stability at 15 min deposition was due to the coating morphology. Longer immersion times were detrimental to the protection efficiency, as the coating layer became more defective.

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