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Imaging defective electronic states in ultrathin CeO2Nanostructures grown on graphene by pulsed laser deposition
2025 - SILVA, DIEGO E.L.; GONCALVES, BARBARA P.; VASCONCELOS, NICOLAS P.; BARRETO, RAFAEL R.; VELOSO, RENATO; OTUBO, LARISSA; FONSECA, FABIO C.; LACERDA, RODRIGO G.; MALACHIAS, ANGELO; PANIAGO, ROGERIO M.; FERLAUTO, ANDRE S.
We report here the growth of ultrathin films of ceria by pulsed laser deposition on HOPG/graphene substrates. The controlled growth of CeO2(111) nanoislands on graphene via pulsed laser deposition (PLD) demonstrates a strong dependence on the substrate defect density, where defects serve as preferential nucleation sites. Higher oxygen partial pressure during deposition enhances surface diffusion, promoting the formation of triangular dendritic nanostructures. Scanning tunneling spectroscopy (STS) reveals mutual electronic interactions between the ceria nanoislands and the graphene substrate, while high-resolution STM imaging identifies ordered oxygen vacancy arrays within the CeO2surface. Bias-dependent STM mapping further highlights the complex electronic configuration of the islands. The presence of these ordered defects suggests the potential for precise spatial control, enabling tailored electronic properties through doping or optimized graphene interactions. These findings advance defect-engineered oxide nanostructures, offering promising applications in catalysis, sensing, and optoelectronics via vacancy manipulation in ultrathin films.
The use of irradiation for production of oligochitosan conjugated with graphene oxide
2025 - GONCALVES, KARINA de O.; DUARTE, MIGUEL; VIEIRA, DANIEL P.; ARAUJO, SUMAIR G.; LANDINI, LILIANE; SAKATA, SOLANGE K.
Chitosan and derivatives, such as oligochitosan, have been attracting significant attention in the biomedical field due to their versatility, biocompatibility, and environmental sustainability, presenting a promising alternative to synthetic materials. Obtained through the deacetylation of chitin, these biopolymers exhibit important characteristics, including biodegradability and the capacity to interact with a range of materials, which makes them suitable for a variety of applications, especially in the development of nanocomposites. The aim of this work was to obtain oligochitosans (OCH) via gamma radiation at a dose of 40 kGy, dose rate 9.8 kGy/h to functionalize graphene oxide (GO) for biomedical applications. The resulting nanocomposite (OCH/GO) was characterized by DLS, scanning microscopy and atomic force microscopy and evaluated for its cytotoxicity, demonstrating that the incorporation of the materials reduces the toxicity of GO, allowing its application in tissue engineering. The objective of this study was to produce oligochitosans (OCH) by gamma irradiation for the functionalization of graphene oxide (GO) and to assess the cytotoxicity of the resulting nanocomposite for biomedical applications. The OCH/GO nanocomposite was characterized using X-ray diffraction, scanning electron microscopy, and atomic force microscopy. Incorporation of oligochitosan reduced the intrinsic toxicity of GO, thus enhancing its potential suitability for applications in tissue engineering.
Innovative defect engineering
2025 - GUSMAO, CAROLINA; PALHARIM, PRISCILA H.; RAMOS, BRUNO; GOUVEA, DOUGLAS; RODRIGUES JUNIOR, ORLANDO; TEIXEIRA, ANTONIO C.S.C.
Volatile Organic Compounds (VOCs) pose significant environmental and health risks, requiring the advancement of effective control techniques. This study presents a novel and cost-effective synthesis method for incorporating Ti3+ sites and oxygen vacancies into TiO2 photocatalysts through sulfur doping, varying the thiourea content during synthesis. The synthesized modified TiO2/SiO2 materials were fully characterized using various techniques, including XRD, TEM, SEM, XPS, EPR, PL and BET. The analysis revealed the presence of crystalline defects. Notably, the EPR analysis indicated a correlation between the increase in bulk defects and the higher thiourea content. The photocatalytic efficiency of the synthesized materials was evaluated using n-hexane in a gas-solid reactor under UV–VIS radiation, showing a significant increase (34.2 % – 61.2 %) in degradation with the introduction of defects in the material. The operating conditions, such as humidity and the presence of oxygen, were varied, revealing a strong influence on the synthesized photocatalysts containing crystal defects. Notably, low humidity substantially increased photocatalytic activity, reaching 78.6 % degradation at 0 % of relative humidity. The stability of the material was examined over 180 min, with sustained high photocatalytic activity. Kinetic studies were carried out to explore varying input concentrations and transient regimes, providing valuable information on the performance of the continuous gas solid photocatalytic reactor (GSPR). This innovative synthesis approach is thus promising for efficient VOCs abatement with improved material performance and stability.
Recycling and processing of plastics by ionizing and non-ionizing radiation
2025 - HARADA, JULIO; ARQUINTO, JULIANA; PEREIRA, MARIA da C.C.; SANTOS, MARIA E.M. dos; CASTRO, DIONE P. de; SILVA, LEONARDO G. de A. e
Plastic waste contributes negatively to the environment by increasing space occupation, creating health hazards on land, in the air, and at sea. For this reason, they need to be disposed of properly so that they can be recycled efficiently. To combat these impacts and reduce environmental pollution, this project aims to study the recycling process of polypropylene (PP) from industrial waste scraps and polypropylene from urban solid waste (MSW) using ionizing radiation from 0 to 500 kGy. Irradiation processing showed efficiency when compared to other recycling processes, promoting the molecular shearing of PP, reaching ideal lengths of shorter chains to be used as a carrier for additives for adhesives and plastics, and/or to be used as a flow modifier for injecting parts. Ionizing radiation above 100 kGy initiated the formation of cross-links, cross-linking the PP that could be used as fillers for asphalt, construction, and other applications, or as a fuel energy source, contributing to the ecosystem, without changes in the curly lettuce after ecotoxicity tests. The use of ionizing radiation in polymer processing has a great advantage when compared to other plastic recycling systems.
Microwave-assisted synthesis of ZnO/BiNbO4 heterojunctions for enhanced hydrogen production
2025 - KUZNETSOVA, MARIA; PALHARIM, PRISCILA H.; CLAUDINO, CAROLINE H.; ACUNA, JOSE J.S.; FRIN, KARINA P.M.; JUSTIN, CHRISTOPHE C.; HYND, REMITA; SOUZA, JULIANA dos S. de
This work introduces a novel heterojunction between ZnO and BiNbO4, prepared through a microwave-assisted technique that significantly reduces time and energy consumption for the synthesis. The used method requires 48 minutes to obtain vertically aligned wurtzite ZnO films and 30 minutes to obtain globular orthorhombic/triclinic BiNbO4. The heterojunction exploits the suitable band alignment of ZnO and BiNbO4 to construct an S-scheme structure, achieving enhanced charge separation and transfer. The prepared ZnO/BiNbO4 heterojunction was used as a photoanode for water photosplitting, exhibiting a fourfold increase in photocurrents for oxygen evolution compared to pristine ZnO. The heterojunction has also demonstrated photocatalytic activity for hydrogen production that is 3.5 and 2 times higher than that of bare ZnO and BiNbO4, respectively. These findings highlight the promising potential of ZnO/BiNbO4 heterojunctions for advanced photocatalytic and photoelectrocatalytic applications, particularly in hydrogen production.
Evaluation of antimicrobial photodynamic therapy with erythrosine and blue light emitting diode for inactivation of Aggregatibacter actinomycetemcomitans
2025 - LATORRE, JOAQUIN I.; GONÇALVES, MARCELA L.L.; GONZALES, CAROLINA S.W.; KASSA, CLAUDIO T.; RODRIGUEZ, MIKELHY S.; TORTAMANO, ANA C.A.C.; MAGALHAES, FABIANA D.; KATO, ILKA T.; BUSSADORI, SANDRA K.; PRATES, RENATO A.
This study aims to analyze the effect of antimicrobial photodynamic therapy on Aggregatibacter actinomycetemcomitans using erythrosine as a photosensitizer and a blue light emitting-diode as a light source. Inoculum samples of A. actinomycetemcomitans with PBS were used in each of the groups, being the control group (C); light group (L) corresponding to light emitting-diode irradiation for 300 s; photosensitizing group (0) without irradiation; and the aPDT groups with different irradiation times (aPDT20) with 20s of irradiation; (aPDT40) with 40s of irradiation; (aPDT60) with 60s of irradiation; (aPDT180) with 180s; and (aPDT300) with 300s. Samples were used to determine colony forming units (CFU). Aliquots of 10 μL were plated through six serial dilutions on brain-heart infusion agar in Petri dishes. The plates were incubated at 37 °C for a period of up to 24–48 h under microaerophilic conditions to evaluate the total bacteria recovered. After this period, CFUs were counted, and the data was subjected to one-way analysis of variance. When aPDT was performed for 180 and 300 s, the mean log10 (CFU/ml) was equal to 0. In the aPDT60 group, a significant yet incomplete microbial reduction was observed. SEM images confirmed that membrane integrity was maintained, indicating that aPDT induced cellular alterations without causing membrane disruption. Antimicrobial photodynamic therapy employing erythrosine as a photosensitizer and blue light emitting-diode light-curing unit for composite resin polymerization used in dental practices demonstrated significant antimicrobial efficacy against A. actinomycetemcomitans, a principal pathogen in periodontitis, under the evaluated experimental conditions.
Magnesium whitlockite structure
2025 - LEMOS, EMANUEL C.M.; MORIYA, RENATA H.; JESUS, LUCCAS C.T. de; BORGES, ROGER; OLIVEIRA, RENE R. de; LIMA, NELSON B. de; ARANTES, JEVERSON T.; MARCHI, JULIANA
Magnesium whitlockite (Mg-WH), the second most abundant inorganic material in hard tissue, is a promising biomaterial and participates in cell signaling through piezoelectric modulation. However, its electric structure is not fully understood. This study investigated the structure and electronic structure of Mg-WH for the first time using ab initio methods. Additionally, Mg-WH was synthesized through the coprecipitation method and characterized by scanning electron microscopy (SEM-FEG), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The experimental results of XRD were compared with those obtained by computational simulation, and good agreement was shown. The Ca1 site of Mg-WH showed a higher distance between magnesium and other coordinated oxygens, making it more likely to accommodate atomic substitution in Mg-WH doping concerning elements with ionic radii bigger than Mg2+. Besides, the theoretical model confirmed the presence of a hydrogen bond due to the presence of the HPO42-group at the Ca4 site, which was further confirmed by the experimental FTIR spectrum. This hydrogen bond and Mg2+ in Mg-WH may play an essential role in physiological environments.
Extensive characterization of arapaima gigas follicle-stimulating hormone (ag-Fsh) synthesized in HEK293 cells
2025 - LIMA, ELIANA R.; SEVILHANO, THAIS C.A.; FEITOSA, THAIS C.; OLIVEIRA, JOAO E.; SUZUKI, MIRIAM F.; TORATI, LUCAS S.; BARTOLINI, PAOLO; PERONI, CIBELE N.
The cDNA sequences of the common gonadotrophic hormone alpha-subunit (ag-Gth alpha) and of the specific follicle-stimulating hormone beta-subunit (ag-Fsh beta) of the giant Amazonian fish Arapaima gigas have been previously isolated by our research group. A synthesis of ag-Fsh in HEK293 cells and its purification and preliminary characterization were also carried out. In the present work, ag-Fsh was obtained and purified from the same host cells, and an extensive physical chemical characterization was performed via RP-HPLC, HPSEC, and MALDI-TOF-MS. Ag-Fsh, when compared to human FSH (hFSH), showed a higher hydrophobicity by RP-HPLC and a higher molecular mass (MM) via HPSEC. The same higher MM was also confirmed via MALDI-TOF-MS: 35,353 Da for ag-FSH against 31,969 Da for hFSH. Its immunological activity was also confirmed via an hFSH ELISA, in comparison with the highly purified pituitary preparation of hFSH-AFP7298A, from the National Hormone and Pituitary Program (NHPP-USA), with a clear response that was, however, 1560-fold lower when compared to the purest preparation. Finally, an in vitro bioassay, based on the stimulated release of 11-ketotestosterone (11-KT) from immature A. gigas testis, quantified ag-Fsh biological activity in comparison with human chorionic gonadotropin (hCG) and with human pituitary FSH-AFP7298A, showing a potency clearly higher than that of hCG. This suggests that injections of ag-Fsh in A. gigas and ag-Fsh cDNA gene therapy applications could be used for improving the reproductive functions of this threatened species.
Microbiologically influenced corrosion of Al–Cu–Li alloy by Pseudomonas aeruginosa
2025 - RAMIREZ, C.G.; MONSALVE, A.; MONTERO, C.; ESPINOZA, J.; ARAUJO, J.; VEJAR, N.; AZOCAR, M.; GULPPI, M.; JIMENEZ-AREVALO, V.M.; ZHOU, X.; PAEZ, M.A.
This study investigates microbiologically influenced corrosion (MIC) of the Al–Cu–Li alloy AA2060-T8 caused by Pseudomonas aeruginosa. Key parameters—bacterial population (OD600), specific biofilm-forming capacity (SBF), pH, and open circuit potential (OCP)—were monitored over time and correlated with bacterial growth stages. A colonization time range between 3 and 10 h was identified (OD600: 0.23–0.67), during which P. aeruginosa produced a critical biofilm amount (SBF: 0.14–0.74) sufficient to sustain irreversible adhesion on the alloy surface, as indicated by the OCP increase from 4 h. Furthermore, a pH decrease from 7.6 to 6.8 was observed during the exponential stage, likely reaching pH 3.5–4.5 within colony cores. This could have created conditions that facilitated the destabilization of the oxide layer beneath the biofilm, making the alloy more susceptible to localized corrosion. After 24 h of exposure to the MIC testing solution, cross-sectional analysis of the alloy revealed discontinuities within the biofilm, which allowed the electrolyte to reach the alloy surface and promote the formation of local differential cells. Thus, MIC of the AA2060-T8 alloy caused by P. aeruginosa is mainly due to the combined effects of pH decrease and the formation of discontinuities acting as channels within the biofilm. These findings provide new insights into the MIC of Al–Cu–Li alloys, paving the way for future protection strategies against MIC.
Investigating solid-state reactions in UAl2-Al dispersions for Mo-99 target fabrication
2025 - RESTIVO, THOMAZ A.G.; CONTURBIA, GIOVANNI de L.C.; CARVALHO, ELITA F.U. de; DURAZZO, MICHELANGELO
Molybdenum-99 (Mo-99), the parent isotope of the widely used medical radioisotope technetium-99m (Tc-99m), is primarily produced via neutron irradiation of uranium-containing targets in research reactors. UAl2-Al dispersions, with UAl2 particles embedded in an aluminum matrix, are commonly employed for target fabrication. This study employs a new method for investigating the solid-state reactions between UAl2 and the Al matrix during target fabrication using stepwise isothermal dilatometry (SID). The study focuses on the formation of UAl3 and UAl4, which are less dense than UAl2 and result in material expansion detected by the linear displacement, which relates to reaction conversion. By analyzing the linear expansion data from 560 ◦C to 630 ◦C, SID determines apparent activation energies and identifies the D2 diffusion rate model as the best fit, indicating a fast reaction rate along the UAl2/Al interfaces and highlighting the crucial role of interface diffusion in the process. This information is crucial for optimizing target fabrication and controlling the final composition of Mo-99 targets.
The brightness of lectins conjugated to quantum dots
2025 - LIMA, JOAO V.A.; OLIVEIRA, WESLLEY F.; SILVA, ABDENEGO R.; MELO, FRANCISCO P.T.; RIBEIRO, MARTHA S.; CABRAL FILHO, PAULO E.; FONTES, ADRIANA
One of the main focuses of glycobiology is investigating the synthesis and modification of carbohydrates in biological systems, due to their involvement in various processes such as cell recognition, differentiation, and immune response. Since the study of these glycans contributes to the understanding of complex biological functions, these biochemical compounds can be analyzed using lectins, which are ubiquitous proteins in nature capable of specifically recognizing carbohydrates. In addition, lectin-carbohydrate interaction can be visualized by conjugating these proteins with quantum dots (QDs), which are fluorescent nanoprobes with advantageous properties, including photostability and size-tunable emission. QDs also possess chemically active surfaces that enable the attachment of biomolecules, such as lectins. In this review, we provide detailed reports of studies involving QD-lectin conjugates conducted by the Biomedical Nanotechnology Group at the Federal University of Pernambuco (UFPE/Brazil) and its collaborators. An integrated perspective on the use of QD-lectin conjugates to study saccharides in a range of biological systems, from bacteria and fungi to red blood cells and cancer tissues, is also presented. We hope this comprehensive review inspires further studies exploring the brightness of lectins upon conjugation with QDs to unravel glycobiological processes.
Poloxamer-Driven drug delivery system for anti-inflammatory drugs using ssmall-angle neutron scattering approach
2025 - RHINOW, RODRIGO; FRANCO, MARGARETH K.K.D.; VOLLRATH, MONT K.; KELLERMANN, GUINTHER; YOKAICHIYA, FABIANO
Poloxamer-based drug delivery systems are widely used in the pharmaceutical sector. The structural characterization of these systems is crucial for the development of new drug delivery systems and for the optimization of their properties. In this study, we utilized small-angle neutron scattering (SANS) to investigate the structures of poloxamerbased drug delivery systems. The samples were measured using the SANS technique on the VSANS-V16 instrument at Helmholtz-Zentrum Berlin (HZB), Germany. The samples contained 20% poloxamer (P407) and 0.2% of a drug (ibuprofen, ketoprofen, diclofenac) in deuterated water (D2O) for SANS. The samples varied in terms of temperature analysis (25 ◦C, common storage temperature; 37 ◦C, human body temperature; 40 ◦C, fever temperature). The data analysis involved modeling the data using a Python-based routine. The model used consisted of an isotropic solution of polydisperse spherical micelles. The intensity as a function of the scattering vector was modeled as the product of the form factor and the interparticle structure factor, with the latter described within the local monodisperse approximation regime. Additionally, a scattering contribution was observed, which was associated with the presence of crystalline superstructures formed by micelles that organized into a cubic structure. The data analysis provided important information about the system, such as the average radius, the size distribution, and the thickness of the layer surrounding the micellar core. The results will contribute to the development and optimization of new drug delivery systems that are more effective and safer for medical applications.
The influence of manufacturing parameters and heat treatments on the properties of AlSi10Mg Alloy produced using L-PBF
2025 - RIBEIRO, GLEICY de L.X.; REIS, LUIS; OLIVEIRA, RENE de; MASSI, MARCOS; GONÇALVES, RODOLFO L.; COUTO, ANTONIO A.
AlSi10Mg has been one of the most studied and employed aluminum alloys for additive manufacturing via laser powder-bed fusion (L-PBF). The optimization of manufacturing parameters is important for reducing internal defects, including porosity and inadequate surface finishes. In addition, heat treatments, such as T6, are often applied to this alloy, but they degrade the characteristic microstructure obtained via L-PBF additive manufacturing— the fine cellular structures—which may, in turn, detrimentally affect the material’s properties. In this context, a new alternative to this treatment, direct aging (DA), has shown promise in improving the mechanical properties of AlSi10Mg parts produced via L-PBF, since it preserves the cellular microstructure, precipitating silicon-rich nanoparticles within the cells. Understanding how different temperatures and heat treatment times influence the microstructure and, consequently, the properties remains a field to be explored in order to optimize the treatment conditions and achieve better mechanical properties. Thus, the objective of this study was to evaluate the influence of manufacturing parameters and heat treatments on the microstructure and mechanical properties of AlSi10Mg alloy. The optimized manufacturing conditions were 300 W power, 800 mm/s scan speed, 30 μm layer thickness, and an argon atmosphere, which led to lower porosity and better finishing. Samples were heat-treated via DA at 150 ◦C and 170 ◦C for different times, as well as undergoing a T6 treatment (solution at 520 ◦C followed by aging at 150 ◦C and 170 ◦C). Initially, the aging curves show higher hardness values for the direct aging condition, compared to the T6 and as-built conditions, reaching a peak hardness of 195 HV for 6h of direct aging. In this way, it was followed with microstructural characterization, which demonstrated that DA maintained the fine cell microstructure of L-PBF and promoted the precipitation of Si nanoparticles, which certainly contributed to the increase in hardness compared to T6, which promoted a structure with coarser precipitates. DA at 170 ◦C for 6 h increased the tensile strength to 430 MPa, compared to the as-built condition, with a slight loss of ductility. Keywords: heat treatment;
Production and characterization of texture in PCD cutting tools with femtosecond laser
2025 - SOUZA, FELIPE C.R. de; ROSSI, WAGNER de; SILVA, LEONARDO R.R. da; PAULA, FABIO R. de; MACHAFO, ALISSON R.
This study investigates the creation of textures on polycrystalline diamond (PCD) cutting tools using femtosecond laser processing and evaluates the influence of these textures on the turning of AA2011-T4 aluminum alloy. Four types of linear textures with varying orientations and dimensions were developed, and their quality was assessed through 3D profilometry and energy-dispersive spectroscopy (EDS). The turning tests evaluated the surface roughness of the machined workpiece, material adhesion on the tool, and the effect of incorporating solid lubricant microparticles (MoS₂) into the textures. The results indicate that femtosecond laser texturing was effective, causing no thermal damage or graphitization of the PCD. During machining, textures oriented perpendicular to the cutting edge reduced aluminum adhesion and lead to better surface finish. In contrast, textures parallel to the cutting edge intensified material anchoring, increasing the risk of tool structure failure. The use of MoS₂ decreased material retention within the textures, facilitated chip evacuation, and contributed to improved machining performance. The greatest reduction in roughness (49 %) was observed for larger perpendicular textures combined with MoS₂. Additionally, larger textures demonstrated superior performance by promoting chip segmentation and reducing thermal effects. The results demonstrate that femtosecond laser texturing is a viable technique for optimizing the performance of cutting tools in the turning of aluminum alloys, enhancing the surface quality of the machined part, and reducing tool wear.
In vitro study of the effects of diode laser on dentin hypersensitivity and evaluation of intra-pulpal temperature variation
2025 - RODRIGUEZ, CHRISTIAN G.B.; MANNA, MARIA P.N.C.; TARRILO, FIORELLA E.A.; ZEZELL, DENISE M.; EDUARDO, CARLOS de P.
To evaluate the efficacy and safety of different wavelengths of high-power diode lasers for the treatment of dentin hypersensitivity by analyzing morphological changes and temperature variation. Human third molars were irradiated with five different commercially available lasers at wavelengths of 808 nm, 940 nm, 976 nm, and 980 nm, both with and without the use of a photoinitiator (activated charcoal). Temperature variations were monitored using thermocouples, and morphological changes were assessed through scanning electron microscopy. Lasers with wavelengths of 940 nm, 976 nm, and 980 nm, used without a photoinitiator, promoted dentinal tubule obliteration without causing thermal damage. Lasers with wavelengths of 808 nm, 940 nm, 976 nm, and 980 nm, when combined with a photoinitiator, resulted in even lower temperature variation compared to the non-photoinitiator groups, although no regular fused surface was observed. Diode laser parameters, except Group 1(808 nm without photoinitiator), are potentially safe for dentinal tubule obliteration. The use of a photoinitiator continues to be an effective strategy for minimizing temperature variations during irradiation.
Wetting front dynamic study in Brazilian cements using neutron and X-ray imaging techniques
2025 - ROSENBERGER, HIGOR; BULLA JR, MARCIO A.; GARCEZ, ESTELA O.; KARDJILOV, NIKOLAY; YOKAICHIYA, FABIANO; FRANCO, MARGARETH K.K.D.
Cement-based materials have a complex porous structure that changes over time, and the durability of such materials strongly correlates to the transport of water and ions throughout the pore structure. The type of cement plays an important role on concrete durability. In this study the dynamics of water absorption using three different types of Portland cement: i) high-early strength cement, ii) ground granulated blast furnace slag (GGBFS) blended cement, and iii) pulverized fly ash (PFA) blended cement, at two different curing ages (7 days and 60 days) were investigated. Neutron radiography technique was used for continuous monitoring of the water absorption in cement paste samples, as shown in the film measured by 3 h, showing the radial and longitudinal penetration of water. The evolution of the wetting front was quantified, analyzed and it was observed that the volume of absorbed water presents behavior according to the square root of time based on neutron images for all samples. X-ray tomography technique was used to investigate the differences between the pore structure and volume of pores (air voids). Finally, this article shows that image techniques is a suitable method for analyzing the size, surface and location of single air voids. The combination of the results from X-ray Tomography and Neutron Radiography shows the potential application of these methods for determining air void parameters and demonstrates how microstructure, type of cement and curing time modified the dynamic water absorption. As expect the fastest absorption was observed on the samples cured for 7 days, however results show clear differences between the three types of cement. At the longer curing time, although no significant differences were found in water absorption, there were important differences in the total number and volume of air voids.
Immunomodulatory green nanomedicine production, tumor cellular targeting, in vivo biodistributions and preclinical therapeutic efficacy investigations of resveratrolfunctionalized gold and theranostic 198gold nanoparticles
2025 - SAKR, TAMER M.; THIPE, VELAPHI C.; KATTI, KAVITA K.; WATKINSON, LISA; CARMACK, TERRY; SMITH, CHARLES J.; CUTLER, CATHY; HEGDE, PRAJNA; HEGDE, ANANTKUMAR; LUGAO, ADEMAR B.; KATTI, KATTESH V.
Prostate cancer remains a major global health concern demanding innovative therapeutic strategies. This study introduces a novel green nanotechnology approach for the development of a nanomedicine agent, also referred to as a nano-radiopharmaceutical, which integrates the antitumor and high antioxidant capacity of resveratrol phytochemical (RESV) with radioactive gold nanoparticles (198AuNPs) for targeted prostate cancer therapy and diagnostics. The radioactive formulation, RESV–198AuNP, was developed at the University of Missouri Research Reactor (MURR) using neutron-activated gold-198, which exhibited high radionuclidic and radiochemical purity. Stability testing in rat serum and saline demonstrated durability of up to 15 days. In vivo biodistribution studies in CF-1 mice and PC-3 tumor-bearing SCID mice have provided insights into pharmacokinetics and optimum tumor retention. Intratumoral administration of RESV–198AuNP in SCID mice demonstrated strong retention within prostate cancer xenografts, suggesting tumor-specific uptake and retention. This study underscores the potential of RESV–198AuNP as a dualfunctional nano-radiopharmaceutical for prostate cancer theranostics. By combining resveratrol’s anticancer properties with the therapeutic and imaging benefits of 198AuNPs, this platform offers a promising avenue for improving treatment efficacy and enabling real-time therapeutic response monitoring. This research reveals the potential of RESV as a tumor-targeting agent and introduces a new perspective of green nanotechnology for dual anti-inflammatory radiosynovectomy as well as for use in cancer treatment. In-depth in vivo studies on the therapeutic efficacy of intratumorally administered RESV–198AuNP revealed that over 85% of the injected dose (ID) remained within prostate tumors for up to 24 h. By the fourth week post-treatment, the treated group exhibited a greater than tenfold reduction in tumor volumes than the control group receiving saline. This study highlights emerging opportunities in green nanotechnology and introduces a clinically feasible approach to utilize resveratrol as a tumortargeting agent in oncology, particularly for the application of RESV–198AuNP in cancer treatments.
Silver accumulation and ionomic profile alterations in pigs
2025 - SANTANA, BIANCA de M.; TREMILIOSI, GUILHERME C.; BATISTA, BRUNO L.; MONTEIRO, LUCILENA R.; SEABRA, AMEDEA B.; GONCALVES, JOAQUIM C.A.; SILVEIRA, HEBERT; COELHO, FLAVIO de A.; ALVES, LAYA K.S.; GARBOSSA, CESAR A.P.; LANGE, CAMILA N.
The antimicrobial properties of silver nanoparticles (AgNPs) in animal feed have drawn increasing attention as a potential alternative to antibiotics. However, concerns about bioaccumulation and possible effects on mineral homeostasis require a thorough evaluation. This study investigates the bioaccumulation of Ag in various tissues and ionomic alterations in pigs fed AgNPs complexed with carbohydrates (AgNPs@Carb). Silver concentrations were measured in tissues, such as the liver, kidney, spleen, heart, and cecal contents, at different time points following the withdrawal of the nanoparticle-supplemented diet. Principal component analysis (PCA) assessed the concentrations of 18 elements across 10 tissues. Results indicate that silver primarily accumulates in the liver and cecal contents, with varying clearance rates across tissues. The silver estimated daily intake (EDI) for human consumption was evaluated, revealing low values across all tissues. This suggests that potential exposure to Ag through the consumption of edible tissues from animals supplemented with AgNPs is minimal and does not pose an immediate health risk. Significant changes were also observed in the ionomic profiles, suggesting that AgNPs disrupt trace element homeostasis. These findings underscore the importance of understanding both the biodistribution of silver nanoparticles and their potential long-term impact on animal health and human consumers.
New insights into the role of the doping process on the luminescence properties of MgB4O7:Ce,Li
2025 - SANTOS, JORGE L.O.; SOUZA, ADELMO S.; VALENÇA, JOAO V.B.; TROMBINI, HENRIQUE; RADTKE, CLAUDIO; SILVEIRA, IURY S.; FERNANDES, ROGER G.; LIMA, HEVESON
Magnesium tetraborate (MgB4O7) has garnered significant attention in recent years for ionizing radiation dosimetry applications. Despite advances in the material’s performance, the fundamental mechanisms underlying lithium (Li) and cerium (Ce) doping and co-doping remain unclear in the literature. In this study, we comprehensively investigate the role of Li and Ce doping in modulating the luminescence behavior of MgB4O7. To elucidate the underlying mechanisms, we employed an advance multi-technique characterization approach using nuclear reaction analysis, synchrotron-based X-ray nanospectroscopy, X-ray photoelectron spectroscopy (XPS), thermoluminescence (TL) spectrum emission, and photoluminescence (PL) spectroscopy. We have shown that Li remains into the host matrix during the synthesis, being associated with shallow traps such as F2+ center. Also, approximately 50% of Ce4+ is reduced to Ce3+ on the material’s surface, forming complex defect structures involving Ce ions and F-center. Additionally, we present strong evidence that the TL emission around 580 nm originates from F-centers rather than trace Mn elements. Some mechanisms that compete simultaneously with each other have been proposed. Our integrated strategy provides insights into the complex dopant-induced electronic and optical transformations in MgB4O7, offering a detailed understanding of the material’s luminescence characteristics.
Processing and EPR characterization of europium, thulium co-doped yttria (YET) powders for radiation dosimetry
2025 - SANTOS, S.C.; RODRIGUES JR, O.; CALDAS, L.V.E.
Radiation dosimetry demands a continuous effort in development of new materials due to its essential purpose, accuracy and quality assurance in all procedures in which radiation energy is used. Rare-earths are critical materials due to their great chemical and physical properties, whose applicability has been shown very relevant in radiation dosimetry. The present study reports an approach to obtain europium, thulium co-doped yttria powders (YET) by an alternative hydrothermal synthesis for application in radiation dosimetry. According to results, the proposed synthesis method provided YET powders with cubic C-type form, flake-like shape, and narrow particle-size distribution with mean diameter (d50) of 148 nm. Moreover, the EPR spectra of the as-synthesized powders exhibited a resonance peak recorded at 335.52mT, with g-value of 2.0094, and peak-width of 3.23mT. As exposed to ionizing radiation (60Co) in a range of dose from 1 to 20 kGy, YET powders exhibited distinct dose-response behaviour as a function of dose, including a slight change in g-factor. These findings are substantial parameters to go forward in formation of new materials for radiation dosimetry.

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