Eventos - Resumos

URI Permanente para esta coleçãohttps://repositorio.ipen.br/handle/123456789/8932

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Agora exibindo 1 - 20 de 6149

Avaliação térmica de compósitos de PEAD/CCA irradiados por feixe de elétrons
2024 - SANTOS, MARIA E.M. dos; SILVA, LEONARDO G. de A. e; HARADA, JULIO
Comparative mineralogical analysis of Brazilian Portland Cements using two differente approaches
2024 - ROSSETTO, C.M.; CARVALHO FILHO, E.T. de; PECCHIO, M.; MARTINEZ, LUIZ G.; TURRILLAS, X.
Caracterização microestrutural, elétrica e mecânica de compósitos de zircônia estabilizada com ítria/galato de lantânio dopado
2024 - MUCCILLO, ELIANA N. dos S.; FUJIMOTO, TALITA G.; SERIACOPI, V.; MACHADO, I.F.; MUCCILLO, REINALDO
Catalisadores Nanoestruturados de Ni/Fe Suportados em CeO2 para Reforma a Vapor do Etanol
2024 - PAULA, DRYADE F. de; MORAES, TAMARA S.; VEIGA, E. dos S.; FONSECA, FABIO C.
Catalisadores Nanoestruturados de Ni/Fe Suportados em CeO2 para Reforma a Vapor do Etanol
2024 - PAULA, DRYADE F. de; MORAES, TAMARA S.; VEIGA, E. dos S.; FONSECA, FABIO C.
Otimizando a Atividade Fotocatalítica de Nanopartículas de ZnO Dopadas com Cl através da Lixiviação Seletiva de Superfície
2024 - SILVA, ANDRE L. da; FORTES, G.M.; RAMOS, B.; BETTINI, J.; FONSECA, FABIO C.; GONÇALVES, R.V.; RODRIGUES JUNIOR, ORLANDO; GOUVÊA, D.
Uma nova visão sobre o papel das partículas intermetálicas na estrutura do filme anódico e no desenvolvimento da corrosão de ligas de alumínio anodizadas
2024 - ARAUJO, JOÃO V. de SOUSA; COSTA, ISOLDA
CrystalWalk
2024 - LEAL NETO, RICARDO M.; BARDELLA, FERNANDO; BARROS, B.D.
Silica synthesis from biomass
2025 - FUNGARO, DENISE A.
Agribusiness activities are generating large amounts of waste due to production processes and society’s high consumption standard. The most common types of crop biomass waste are straw, bark, cob and bagasse. The amount of agricultural waste generated in the world (million tons/year) is: Rice husk: 130-170; Corn Cob: 164; Sugarcane Bagasse: 700. Most of this waste is disposed of by burning, dumping, or landfilling. Incorrect disposal raises serious questions related to human health and the environment, mainly associated with air pollution, water and soil contamination. The strategy to mitigate the effects of disposal is the reuse of agricultural biomass waste. Wastes such as rice husk, corn cob, wheat straw and sugarcane bagasse present high content of silica in the composition, thus can be utilized for the production of nanosilica (SiNPs). SiNPs present a variety of applications due to their distinctive properties such as stability, biocompatibility, surface reactivity, tunable pore size, and high surface area. Extracting silica from agricultural waste is an excellent alternative to obtain high added-value products. Methods of extracting silica from agricultural waste are divided into thermal, biological and chemical. The chemical synthesis method has the advantage of size and shape control, as well as purity improvement. Among the chemical methods, SiNPs are mainly synthesized via a sol-gel polymeric route. The silica is extracted from the waste as sodium silicate, then treated with acid to convert it into a gel. A transformation occurs in colloidal suspension of sol into gel through 3D interconnecting network. The sol–gel technique allows control the size, distribution, and morphology of particles with a large specific area and high porosity. Pure amorphous silica was successfully extracted at a 99.1% from sugarcane waste ash. The synthesized SiNPs can be characterized by a combination of spectroscopic and chemical techniques, such as XRD, XRF, SEM, TEM, particle size distribution, N2 adsorption-desorption isotherms, TGA, and FTIR. In this approach, the adoption of the circular economy in agroindustrial waste management contributes significantly to the achievement of the Sustainable Development Goals (SDGs), specifically, SDG 12: “By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse”.
Classification of oral cancer using Random Forest
2024 - PERES, DANIELLA L.; SILVA, DANIELA F.T.; GERMANO, GLEICE; BACHMANN, LUCIANO; MATOS, LEANDRO L. de; FELIPE, JOAQUIM C.; PEREIRA, THIAGO M.; ZEZELL, DENISE M.
Bone as a biomarker to differentiate single doses from fractional doses
2024 - GERMANO, GLEICE; CASTRO, PEDRO A.A. de; DIAS, DERLY A.; VELOSO, MARCELO N.; ZEZELL, DENISE M.
A one-dimensional convolutional neural network model for classifying breast cancer subtypes and evaluating biochemical content using micro-FTIR hyperspectral images
2024 - VALLE, MATHEUS del; ZEZELL, DENISE M.
Synthesis and characterization of amino acids organometallic complexes
2024 - ABADESSA, LIDIANE T. da S.; FRANCO, MARGARETH K.K.D.; ARAUJO, JOHN W.B. de; BULLA, MARCIO A.; KAKUNO, EDSON; YOKAICHIYA, FABIANO
The biochemical function of metal ions in many processes is of fundamental importance, both in the human body and in optoelectronic devices. Most metal cations in living organisms interact with proteins, and therefore the study of metal-protein binding sites has attracted much attention in scientific research. Amino acids, which contain proton-donating groups (carboxylic acid, -COO) and proton-accepting groups (amino, -NH2), are fascinating organic materials for applications in semi-organic nonlinear optical (NLO) crystals. Single crystals of amino acids complexed with transition metals exhibit several important physical properties, such as optical (especially nonlinear optics), piezoelectric, and ferroelectric properties. These studies also contribute to the understanding of neurodegenerative diseases, such as Parkinson's, Alzheimer's and Creutzfeldt-Jakob Disease. The zwitterionic characteristic of amino acid molecules facilitates the manipulation of this substance. In this context, the present study was dedicated to the characterization, by X-ray diffraction as a function of temperature and Raman Spectroscopy, of pure and complexed crystals of Nickel L-Histidinate, Nickel L-Alaninate and Copper D-Alaninate, grown by the method of slow evaporation of an aqueous solution, with the aim of enriching studies in this field.
Porphyrin-coated gold nanoparticles associated with radiotherapy in the treatment of triple-negative breast cancer
2024 - SILVA, CAMILA R.; RIBEIRO, MARTHA S.; HEUSKIN, ANNE-CATHERINE
Triple-negative breast cancer (TNBC) is a subtype of breast cancer that accounts for around 20% of all invasive breast cancers and is characterized by resistance to conventional treatments, such as radiotherapy (RT). Photodynamic therapy (PDT) using porphyrins has been described in the literature as a potential therapy against cancer. With advancements in nanomedicine, nanoparticles (NPs) are now being used to deliver the photosensitizer with greater precision and improve the effects of RT. Our goal in this work was to develop an NP coated with porphyrin and combine it with RT in the treatment of TNBC. MDA-MB-231 cells were subjected to PDT using a porphyrin-coated NP and a red light (660 ± 11 nm, 40 J.cm-2). Immediately after PDT, the cells were exposed to RT with a dose of 2 Gy. Reactive oxygen species (ROS) and antioxidant defenses were evaluated, as well as cell viability over time for both monolayer and spheroid cultures. Our results showed that the NPs coated with TMPyP had good stability, high absorption in the red region, and reduced levels of thioredoxin reductase. Furthermore, when the therapies were combined, cell survival decreased over time and ROS levels increased. Thus, our results suggest that the combination of PDT using porphyrin-coated gold nanoparticles and radiotherapy has significant potential and could be an effective strategy in the treatment of TNBC.
Molecular inclusion complex with gama-cyclodextrin
2024 - SAMPAIO, THIAGO S.; MENDONCA, NATALIA S.; CARVALHO, FABIOLA V.; YOKAICHIYA, FABIANO; FRANCO, MARGARETH K.K.D.; PAULA, ENEIDA de
Docetaxel (DTX) is a semi-synthetic derivative of 10-deacetyl-baccatin III, a non-cytotoxic compound extracted from yew leaves (Taxus baccata L). DTX use for the treatment of anthracycline-refractory metastatic breast cancer (1996) was then expanded for skin, lung, prostate, gastric, head/neck and other neoplasias. However, as a class IV BCS drug, the clinical application of docetaxel is limited by its low water solubility (5 mg/L or 6 µM), intestinal permeability and fast elimination. Also, the use of commercially available DTX formulations is associated to adverse effects such as neutropenia, hypersensitivity reactions, peripheral neuropathy, musculoskeletal toxicity and nasolacrimal duct stenosis. To overcome such adverse effects and increase DTX anticancer potential we investigated the inclusion complexation of DTX with cyclodextrins (CD). CD are known to accommodate molecules of proper size and polarity into their macrocyclic ring, forming host-guest inclusion complexes. Complexation in CD may improve the aqueous solubility, increase the stability and prolong the release kinetics of the guest molecule. In here we report results on the characterization of a DTX:gama-cyclodextrin complex. The DTX:gCD inclusion complex was prepared by the co-solubilization method, lyophilized, and characterized regarding the equilibrium time (5 h) and stoichiometry of complexation (1:2). As expected, complexation significantly increased (20-fold) the aqueous solubility of DTX and biophysical techniques (DSC and X-ray) provided evidence of DTX:gCD complex formation. In vitro release kinetics tests were conducted to compare the release of DTX from the complex with that of the commercial DTX formulation (Taxotere®). Finally, cytotoxic effects against breast cancer cells (4T1) and normal fibroblasts (NIH-3T3) had been evaluated. Both DTX:g-CD and Taxotere® caused significant reduction in the cell viability of breast cancer cells, even at the lowest concentration tested (5x10- 11M). Interestingly, DTX:g-CD complex was found to be less toxic to NIH-3T3 non-tumor cells than Taxotere® (cell viability was reduced to 48.5 ± 2.4% with DTX:g-CD and to 20.2 ± 0.8% with Taxotere® at the concentration of 5mM). These preliminary results suggest that DTX:gCD may represent a new drug delivery system, capable of reducing the toxicity and enhancing the effectiveness of DTX in cancer treatment.
Evaluating the impact of photobiomodulation therapy on Pseudomonas aeruginosa-induced acute infectious process
2024 - SILVA, ABDENEGO R.; RIBEIRO, MARTHA S.
Photobiomodulation therapy (PBM) has shown potential in enhancing cellular stimulation, promoting wound healing, and alleviating pain in healthcare settings. However, its effects on infectious processes remain underexplored. This study aimed to evaluate the impact of PBM on inflammation induced by Pseudomonas aeruginosa in a mouse model. The Ethical Committee on Animal Use at IPEN approved this study. After anesthetizing the mice, a suspension of P. aeruginosa was inoculated into their left paws to induce infection. Six-h post-inoculation, sixteen mice were divided into two groups: a control group (CG), which received no treatment, and a laser-treated group (LG). The LG received PBM with a red laser (wavelength 660 nm, power 50 mW) delivering a light dose of 3 J/cm² to the infected paw. Swelling was evaluated using standardized photographs of the paws taken at 0, 16, and 24 h post-treatment, and analyzed with ImageJ software. Data were analyzed using Student’s t-test, with results considered statistically significant at p < 0.05. Results showed a significant reduction in edema in the LG at 16 h and 24 h compared to the initial measurements. At 16 h, the LG exhibited less swelling compared to the CG. By 24 h, edema sizes in both groups were similar. Under the conditions of this work, our findings suggest that PBM does not increase bacterial burden and may effectively reduce swelling in acute infectious process. Further research is warranted to validate its potential as a strategy for managing infectious inflammation.
Complexation of the chemotherapeutic docetaxel with hydroxypropyl-γ-cyclodextrin
2024 - MENDONCA, NATALIA S.; SAMPAIO, THIAGO S.; CARVALHO, FABIOLA V.; YOKAICHIYA, FABIANO; FRANCO, MARGARETH K.K.D.; PAULA, ENEIDA de; SOUZA, TATIANE P. de
Docetaxel (DTX) a chemotherapy drug of the taxane class is recognized as an essential medicine by the World Health Organization (WHO) for treating various cancers, including breast cancer. Classified under class IV of the biopharmaceutical classification system, DTX has low water solubility (6 μM) and limited bioavailability. Commercial DTX formulations employ a non-ionic surfactant (polysorbate 80) and ethanol to enhance solubility which exacerbates the side effects of chemotherapy. Forming inclusion complexes with cyclodextrins (CDs) presents a promising strategy to improve drug solubility. CDs are cyclic oligosaccharides derived from starch degradation by the bacterial enzyme cyclodextrin glucosyltransferase. α-, β- and γ-cyclodextrins are the most abundant natural CDs, but their applications are limited due to poor drug-binding capacity and toxicity concerns, especially in parenteral administration. To address these issues, chemically modified CDs such as hydroxypropyl-γ-CD (HP-γ-CD) have been developed. In this study, a DTX:HP-γ-CD inclusion complex was prepared by the co-solubilization method followed by freeze-drying, in a 1:2 stoichiometric ratio and an equilibration time of 6 hours. Characterization techniques such as scanning electron microscopy (SEM) and X-ray diffraction were employed. The complexation markedly increased the aqueous solubility of DTX by up to 25 times (150 μM). SEM micrographs indicated that DTX loses its crystalline structure upon complexation, resulting in an amorphous arrangement similar to HP-γ-CD. X-ray diffraction confirmed the loss of DTX's crystalline pattern in the inclusion complex, a phenomenon not observed in the physical mixture of excipients. The dimensions of the DTXHP-γ-CD complex (D=18.09, d= 10.13 and h= 8.07 angstroms) compared to pure HP-γ-CD (D=17.57, d= 10.56 and h= 8.96 angstroms) suggest that docetaxel slightly enlarges the size of the external ring and internal cavities (D and d, respectively) of HP-γ-CD and decreases the height of its cone (h); additionally, there was a decrease in peak intensity from the physical mixture to the complex. These results provide compelling evidence of the complexation between DTX and modified γ-cyclodextrin. This complex holds the potential to become a new formulation with reduced side effects and enhanced therapeutic efficacy against cancer.
Characterization of Poloxamer-based drug delivery systems using Small Angle Neutron Scattering
2024 - RHINOW, R.B.; YOKAICHIYA, F.; FRANCO, M.K.K.D.; KELLERMANN, G.
Poloxamer-based drug delivery systems are widely used in the pharmaceutical industry. 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 used small-angle neutron scattering (SANS) to investigate the structure of poloxamer-based drug delivery systems. The samples were measured using the VSANS-V16 instrument at the Helmholtz-Zentrum-Berlin (HZB), Germany. The samples contained 20% poloxomer (PL407) and between 0.1% and 1% of the drugs (Nystatin, Prednosolone, Resveratrol, Doxycycline, Rambutan, Mangustan, Diclofenac, Ketoprofen, Ibuprofen, Paracetamol, Ethanol), in deuterated water (D2O). The samples varied in terms of drug quantity and temperature (25ºC, common storage temperature; 37ºC, human body temperature; 40ºC, the temperature of an individual with fever). The analysis of the systems consists of modeling the data using a Python program. The intensity as a function of the scattering vector, which is a sum composed of the form factor, interparticle structure factor, and the micelles polydispersity can be described within the local monodisperse approximation regime. However, the existence of a cubic macrostructure due to the high concentration of the samples was observed, resulting in the creation of a model that took the cubic structure into account. This allows us to obtain important information about the system, such as the radius of gyration, average radius, aggregation number, and total excess scattering density of a chain in the core and corona. In addition to the SANS data analysis, a sample holder was designed and built for small-angle X-ray scattering (SAXS) in order to study and complement these poloxamer-based drug delivery systems to enrich the characterization of these systems. Currently, the SAXS equipment is being built at Laboratório de Ótica de raios X e Instrumentação (LORXI) at the Federal University of Paraná (UFPR). The results will contribute to the development and optimization of new drug delivery systems that are more effective and safer for medical application.
Progress in clinical diagnosis using neutrons and X-rays
2024 - GOES, MARIA P. de O.; BENEDITO, MARIA G.M.; MOURA, LARISSA A.S.; OLIVEIRA, CLEBER D. de; GIOVANNI, DALTON; ZAMBONI, CIBELE B.
Understanding potential trajectories in health is crucial for guiding long-term policy in the health area. This study provides alternative approaches to clinical practices (dosage of ions and metal) using neutrons and X-rays. In recent years, Neutron Activation Analysis (NAA) and X-ray Fluorescence (XRF) techniques have been applied to this clinical end at IPEN/SP- Brazil, in collaboration with research centers. These analytical techniques have been applied to investigate specific ions and metal in biological samples, in-vitro (serum, blood, urine, saliva) and in-vivo (nails and hair), for monitoring and diagnosis of prevalent diseases in Brazil. The NAA measurements were performed using the IEA-R1 nuclear reactor at IPEN (CNEN/SP-Brazil) and XRF data were obtained using a compact X-ray spectrometer (X-123 SDD, Amptek®) with Ag, Au, and Rh targets. There are several motivations and positive expectations for the use of these alternatives for diagnosis, but the great advantage is the feasibility of using the X-ray experimental set-up facility, outside the nuclear reactor premises, which allows its use in underserved regions without a clinical laboratory. In addition, we provide a robust platform of reference values in biological samples (serum, blood, urine, saliva) that can be explored or implemented by other analytical techniques. We intend to stimulate the biochemical analysis of body fluids as well as in-vivo samples (nails and hair) using a compact and portable X-ray spectrometer setup.
Investigations of metals present in polymer composition of plastic debris by EDXRF technique
2024 - ZANIN, T.; ZAMBONI, C.B.; CARDOZO, B.B.I.; SA FELIZARDO, J.F.; MEIGIKOS, R.
Plastics are one of the most common and persistent pollutants in ocean waters and beaches worldwide, causing harmful effects on marine biota. The composition of these plastics mainly includes polyethylene (PE1) and polystyrene (PS). The marine environment is impacted in various ways and, in extreme cases, diseases can emerge among seafood-consuming inhabitants due to contaminants (such as the toxic additives) in the plastic composition. Specifically, the objective of the present investigation is to analyze ions and metals in PE1 and PS samples exposed in the Jurujuba region (Baía de Guanabara, Rio de Janeiro) for different periods using the Energy Dispersive X-Ray Fluorescence (EDXRF) analytical technique. This analysis will help identify toxic metals present in these polymer compositions as well as metals adsorbed on the plastic surface, contributing to defining measures to address this issue. Samples (in triplicate) were divided into three groups: I) Standard: sample available commercially; II) Control: sample exposed only to ultra-pure water, in the dark with a controlled temperature of 25 degrees Celsius; III) Exposed samples in Jurujuba (Baía de Guanabara, RJ). This study is part of a larger research project “Strengthening capacities in Marine and Coastal Environments using nuclear and isotopic techniques” (IAEA/ARCAL: RLA7025). These results emphases the toxicity of marine pollution, and show that PET and PS polymers can act as carriers of pollutants between ecosystems.

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