816 resultados para Electrophoretic depositions
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Proteinograma do líquido sinovial de equinos hígidosobtido por eletroforese em gel de poliacrilamida
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Dissipadores de calor recobertos com filmes de diamante CVD foram desenvolvidos para acoplar a semicondutores, utilizando-se do Laboratório de Deposição de Filmes de Diamante CVD, na UNESP - Campus de Guaratinguetá e o Laboratório de Diamantes da Universidade São Francisco, em Itatiba, SP. Analisou-se o filme de diamante CVD sobre o silício, para emprego como dissipador de calor, porque o filme de diamante CVD pode ter o valor da condutividade térmica até cinco vezes superior ao do cobre e de dez vezes a do alumínio. Os filmes foram obtidos via deposição através de reator de filamento quente, trabalhando-se com vários filamentos retilíneos em paralelo, resultando assim em um processo que visou obter um filme mais uniforme e com grande área de deposição. Os dados para análises da composição química superficial dos filmes foram obtidos por Difração de Raios-X, Dispersão de Energia de Raios-X e para a verificação da morfologia e espessura do filme foi utilizada a Microscopia Eletrônica de Varredura. Para a verificação do comportamento da temperatura sobre o dissipador com o filme de diamante CVD foi utilizada uma câmera de imagem termográfica, marca Fluke, modelo Ti 40 FT. Foram obtidos filmes de 2 e 10 ?m sobre o silício. Estas espessuras ainda não oferecem um desempenho mecânico que o torne autosustentado. Do ponto de vista de desempenho térmico as análises mostraram que, mesmo com pequena espessura, o filme de diamante CVD apresentou bom resultado experimental. Os principais desafios de construção para esse dissipador de calor são a obtenção do filme com espessura acima de um mm e a garantia da qualidade do filme com a repetitividade do processo em cujo caso torna-se necessário definir as dimensões do dissipador antes da deposição do filme.
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An extracellular pectin lyase secreted by Fusarium decemcellulare MTCC 2079 under solid state fermentation condition has been purified to electrophoretic homogeniety by using ammonium sulfate fractionation, carboxymethyl cellulose and gel filtration (Sephadex G-100) column chromatographies. The purified enzyme showed single protein band corresponding to molecular mass 45 +/- 01 kDa on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme had maximum activity at pH 9.0 and showed maximum stability in the pH range of 9.0-12.0. The optimum temperature of the purified enzyme was 50 degrees C and it showed maximum stability upto 40 degrees C. The energy of activation for the thermal denaturation (Ea) was 59.06 kJ mol(-1) K-1. The K-m and k(cat) values using citrus pectin as the substrate were 0.125mgml(-1) and 72.9 s(-1) in 100mM sodium carbonate buffer pH 9.0 at 50 degrees C. The biophysical studies on pectin lyase showed that its secondary structure belongs to alpha+beta class of protein with comparatively less of beta-sheets. Purified pectin lyase showed efficient retting of Crotolaria juncea fibers.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Due to complications caused by metallic implants in the replacement of bone tissue, the biological application of ceramics raised and became a viable alternative. The titania has the ability to promote bone tissue regeneration based on its structure, mechanical and biologically properties compatibility. The present work aims at obtaining and characterization of Titania (TiO2) porous ceramics produced by the polymeric sponge method (replica method). Polyurethane sponge with 10 ppi and 15 ppi (pores per linear inch) were used. The process differentiation is the air blower used to remove excess slurry. The ceramics sponges were dried in an oven, then pre-sintered at 1000 o C and sintered at 1450 o C. The effect of direct sintering at 1450 o C was also assessed. The percentage of solids used to prepare the slurry was 40 to 45% by weight. To increase the surface porosity of the sponge, 20% of starch was added. There was difficulty on controlling the thickness of the slurry layers on the sponge which resulted in the variation of samples mechanical resistance. Despite this, the results obtained are quite promising for the proposed use, indicating that it is possible to obtain titania sponges with an apparent porosity of around 60%, a bulk density ranging from 40 to 47% and a compressive strength resistance – that with better control of layers depositions – can vary from 1 to 4 MPa
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Sickle cell anemia (SCA) shows a pathophysiology that involves multiple changes in sickle cell erythrocytes, vaso-occlusive episodes, hemolysis, activation of inflammatory mediators, endothelial cell dysfunction, and oxidative stress. These events complicate treatment and culminate in the development of manifestations such as anemia, pain crises and multiorgan dysfunction. The aim of this study was to evaluate, in SCA patients, oxidative stress and antioxidant capacity markers, correlating them to treatment with hydroxyurea (HU), β-globin haplotypes and glutathione S-transferase polymorphisms (GSTT1, GSTM1 and GSTP1), in comparison to a control group (CG). The study groups were composed of 48 individuals without hemoglobinopathies (CG), SCA patients treated with HU [AF (+HU), N = 13] and untreated SCA patients [AF (-HU), N = 15], after informed consent. The groups were analyzed using cytological, electrophoretic, chromatographic and molecular methods and information from medical records. The GSTM1 and GSTT1 polymorphisms were determined by multiplex PCR, while the GSTP1 polymorphism by PCR-RFLP. Biochemical parameters were measured using spectrophotometric methods [TBARS, TEAC and catalase (CAT) and GST activities] and a chromatographic method [glutathione (GSH)]. The fetal Hb (Hb F) levels observed in the SCA (+HU) group (10.9%) confirmed the already well-described pharmacological effect of HU, but the SCA (-HU) group also had high Hb F levels (6.1%), which may have been influenced by genetic factors not targeted in this study. We found a higher frequency of the Bantu haplotype (48.2%), followed by the Benin (32.1%) and also Cameroon haplotypes, rare in our population, and 19.7% of atypical haplotypes. The presence of Bantu haplotype was related to higher lipid peroxidation levels in patients, but also, it conferred a differential response to HU treatment, raising Hb F levels in 52.6% (P = 0.03). The protective effect of Hb F was confirmed, because the increase in their levels resulted in a 41.3% decrease in lipid peroxidation levels (r = -0.74, P = 0.0156). The genotypic frequency of the GST polymorphisms observed was similar to that of other studies in the Brazilian population, and its association with biochemical markers revealed a significant difference only for the GSTP1 polymorphism, where patients with genotype V/V showed higher GSH and TEAC levels (P = 0.04 and P = 0.03, respectively) compared to patients with genotype I/I. The TBARS levels were about five to eight times higher in the SCA (+HU) and SCA (-HU) groups, respectively, compared to controls, and HU produced a 35.2% decrease in lipid peroxidation levels in the SCA (+HU) group (P < 0.0001). Moreover, the SCA (+HU) group showed higher TEAC levels when compared to CG (P = 0.002). We did not find any significant difference in GST activity between the groups studied (P = 0.76), but CAT activity was about 17 and 30% lower in SCA (+HU) and SCA (-HU) groups, respectively (P < 0.00001). Plasma GSH levels were ~2 times higher in SCA patients than in the control group (P = 0.0005) and showed a positive correlation with TBARS levels, confirming its antioxidant function. HU treatment contributed to higher CAT activity and TEAC levels and lower lipid peroxidation, and its pharmacological effect showed a “haplotype-dependent” response. These findings may contribute to elucidating the potential of HU in ameliorating oxidative stress in SCA subjects.
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SnO2-based varistors are strong candidates to replace the ZnO-based varistors due to ordering fewer additives to improve its electrical behavior as well as by showing similar nonlinear characteristics of ZnO varistors. In this work, SnO2-nanoparticles based-varistors with addition of 1.0 %mol of ZnO and 0.05 %mol of Nb2O5 were synthesized by chemical route. SnO2.ZnO.Nb2O5-films with 5 μm of thickness were obtained by electrophoretic deposition (EPD) of the nanoparticles on Si/Pt substrate from alcoholic suspension of SnO2-based powder. The sintering step was carried out in a microwave oven at 1000 °C for 40 minutes. Then, Cr3+ ions were deposited on the films surface by EPD after the sintering step. Each sample was submitted to different thermal treatments to improve the varistor behavior by diffusion of ions in the samples. The films showed a nonlinear coefficient (α) greater than 9, breakdown voltage (VR) around 60 V, low leakage current (IF ≈ 10-6 A), height potential barrier above 0.5 eV and grain boundary resistivity upward of 107 Ω.cm.
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Pós-graduação em Química - IQ
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This article deals with how Milton Hatoum explores aspects of the memory, through the convergence of voices in his four Lusophone novels Tale of a Certain Orient, The Brothers, Ashes of the Amazon and Orphans of Eldorado. A profile of complex characters is constructed through a synthesis of accounts, letters and depositions, as different faces of individuals and society at large are interspersed through memory.
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We describe a heterozygous case of Hb I-Philadelphia [alpha 16 (A14) LYS-->GLU] in a blood donor from the Acre State Blood Bank, in the Brazilian Amazon region. We confirmed the mutation by electrophoretic and chromatographic methods and by DNA sequencing. A literature search showed that this is the first description of this alpha globin mutant in a Brazilian Caucasian group. We also emphasize the importance of the hemoglobin study in blood donors for the purpose of the genetic counseling and quality assurance of the blood to be transfused. Screening tests for hemoglobin mutants are also important for gathering anthropological information about the Brazilian population.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Biofísica Molecular - IBILCE