594 resultados para Prata


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The comet assay is a method of DNA damage analysis widely used to quantify oxidative damage, crosslinks of DNA, apoptosis and genotoxicity of chemicals substances as chemical, pharmaceuticals, agrochemicals products, among others. This technique is suitable to detect DNA strand breaks, alkali-labile sites and incomplete excision repair sites and is based on the migration of DNA fragments by microeletroforesis, DNA migrates for the anode forming a “tail”, and the formed image has the appearance of a comet. The slides can be stained with fluorescence or silver, having differences in the microscopy type used for the analysis and the possibility of storage of the slides, moreover, the first one is a stained-method with more difficulties of accomplishment. The image analysis can be performed by a visual way, however, there is a disadvantage as the subjectivity on the results, that can be minimized by an automated method of digital analysis. This process was studied in this report with the aim to perceive the validation of the digital analysis turning it a quantitative method with larger reproductibility, minimizing the variability and imprecision due to the subjective analysis. For this validation we selected 50 comets photographed in a standardized way and printed, afterwards, pictures were submitted to three experienced appraisers, who quantified them manually. Later, the images were processed by free software ImageJ 1.38x, printed and quantified manually by the same appraisers. The intraclass correlation was higher to comet measures after image processing. Following, an algorithm of automated digital analysis from the measures of the comet was developed; the values obtained were compared with those 12 estimated manually after the processing resulting high correlation among the measures. The use of image analysis systems increases ...(Complete abstract click electronic access below)

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Silver nanoparticles (Ag) were deposited on multi-walled carbon nanotube by eletroless. The hybrid Ag/MWCNT was used in the modification of glassy carbon electrode (GC) surface. The electrochemical characterization confirmed the presence of Ag in the nanocomposite has been showed that the synthesis was successful. The GC electrode modified with Ag/MWCNT film was evaluated for electro-oxidation of benzene. The electrochemical behavior presented an improvement on the catalytic surface in relation to non-modified GC electrode. The anodic peak current increased the magnitude in three times when compared with the CG electrode modified only with MWCNT

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Pipelines are linear engineering works, designed mostly for transporting oil and its derivatives for long distances, furnishing even the farthermost zones of the country. Due to oil sector needs to ensure for the safety and conservation of its properties, several geotechnical studies are being held at the pipelines field, in order to preserve this important transportation, and also to prevent accidents, which might seriously compromise the environment and the population who lives around it. The OSBRA pipeline, who connects the city of Paulínia to the capital Brasília, is one of these engineering works that deserves to be pointed out. This research, performed at the Ribeirão da Prata Basin, was a pilot study conducted with the main objective of testing the current methodology efficiency, for future applications in the closest watersheds to the OSBRA pipeline. The objective of this research is to analyze flood wave and debris flow processes in a non-fictional watershed, by comparing two different kinds of methods: the first one based on simulation models (software ‘ABC 6’), and the other one by flood wave and debris flow susceptibility mapping. The results from the hydrological modeling were both hydrographs and ietographs that estimated values of outputs and infiltration. To construct the susceptibility maps were necessary three other maps: ground use and occupation maps, divided according to the different protection degrees that were offered to the ground; maps of dam locations in the area and physiographic compartimentation maps, divided according to the local geology. To complete the methodology, the results were collected from both methods for comparison. The obtained product for this methodology was series of data whose different susceptibility degrees to flood wave and debris flow could define the safest route for a pipeline crossing in this watershed...

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Given the intense expansion of the industries in Brazil and the discovery of hydrocarbons in the pre-salt layer of the Santos and Campos Basin, there is a need to expand the distribution of oil and gas network in the country. The present work aims to present the development of susceptibility map by two distinct methods of two events (debris flows and full wave), applied to the establishment of pipelines on Ribeirão da Prata Basin. The research area covers two municipalities: São João da Boa Vista and Águas da Prata, in total 145 km2. In the paper was used the methodology proposed by Zaine (2011) for the physiographic subdivision method, which uses geological maps, geomorphological maps, digital terrain models and aerial photographs, used to extract the main elements of the physical environment, as rivers, lines, ridges, tops forms and valley forms and historical processes. Thus, the basin was divided into 11 physiographic zones, considering the following elements: thickness of soil, rock type, geomorphology, amplitude, ridges orientation, erosion occurences and mass movements. Were subsequently performed location maps of dams, that had as main purpose to localize major dams in the study area along with their area and perimeter of the reservoir, and land use map that subdivided the area in woody vegetation, permanent culture, temporary culture and urban area. Along with the preparation of the auxiliar maps was conducted a field campaign with three days and approximately 2 points per km2, which aimed to better understand the physical environment and check the main peculiarities of the study area. Criteria have been established for susceptibility maps physiographic subdivision and land use, and a survey of criteria weights used in each map for both processes under study. For the preparation of susceptibility maps were adopted two different methods, which treat the weighted average and the multiplicand. The weighted average method it is...

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O mexilhão-dourado (Limnoperna fortunei) é um bivalve de água doce pertencente à família Mytilidae. Originário de rios e arroios da China e do sudeste asiático, foi introduzido acidentalmente na América do Sul em 1991, no estuário do rio da Prata, provavelmente através de água de lastro. Como encontrou condições propícias para o seu desenvolvimento, se expandiu através dos rios Uruguai, Paraná e Paraguai, sendo atualmente o principal responsável pelo macrofouling em ecossistemas de água doce do continente. O presente estudo compreende uma área de grande extensão na bacia do Rio da Prata, onde foram amostrados pontos estratégicos nos rios Paraná (e seus principais afluentes), Uruguai e Paraguai. A partir de coletas de organismos do plâncton, realizadas por arrasto vertical, foram quantificadas as densidades de larvas de L. fortunei em cada local de amostragem. Assim, obteve-se um panorama atual da ocorrência do mexilhão, registrando-se, inclusive, alguns limites de sua distribuição. As densidades mostraram-se, no geral, elevadas, provavelmente em decorrência do período de amostragem (verão 2010), onde a atividade reprodutiva da espécie é maior devido às altas temperaturas. Porém, grandes variações ao longo da bacia foram registradas, o que pode estar relacionado ao grau de antropização, disponibilidade de substratos, velocidade da corrente, tempo de introdução, entre outras variáveis

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Brazil is a country with the largest world´s vegetal genetic diversity and the Environmental Protection Area (APA) of the “Serra da Mantiqueira” is a very heterogeneous region, representing one of the richest sources of pharmacologically actives materials. The population uses medicinal plants and according to the OMS, 80% of the population uses them in primary treatment of several diseases. Nevertheless, the loss of traditional knowledge associated with medicinal plants is occurring quickly. The ethnopharmacological strategy uses traditional knowledge to the search for medicinal plants that can have bioactive substances against diseases that afflicting the population and thus protect traditional knowledge. The “cipó-prata” (Trigonia nívea Cambess.) is a native plant normally found in the “Bacia do Paraná” region and present in the flora in the neighborhood of “Marins”, Piquete-SP and usually, said for the treatment of renal and urinary diseases. So, the objective of this study was test if the “cipóprata” (Trigonia nívea Cambess.) has effects on the renal excretion of water and salt, in anesthetized Wister rats. The tests were made in males Wistar rats and randomly distributed into 4 experimental groups: Group I – aqueous control, Group II – treated with aqueous extract (EA) of “cipó-prata”, Group III – water control + “tween 80”, Group IV – treated with ethanol extract (EE) and “cipó-prata”. All groups were subjected to experimental protocol, composed of three periods: Balance (40 minutes), Basal (30 minutes) and Experimental (90 minutes), occurring the urine collection every 30 minutes, from the basal period and measuring blood pressure every 10 minutes. The aqueous extract (EA) of “cipó-prata” (Trigonia nívea Cambess.) presented diuretic effect of 173% (B-2,4±1,19 μL/min reaching 6,6±1,45 μL/min, in the period EX3) and ...(Complete abstract click electronic access below)

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The waste, exaggerated and incorrect disposal of biomass are common practices in modern times where everything is disposable. However the growing concern with the nature and the environment compel man to give nobler destinations for these products through sustainability and recycling of waste. Banana peel is a residual biomass, which is not consumed. It generates tons of waste per week in São Paulo city. This trash is disposed in dumps and landfills, which could be reduced by using it as reinforcement in natural composites. The high density polyethylene (HDPE) is a polymer derived from the ethylene polymerization and is easily recycled. Which makes it a sustainable material. In the present work characteristics of the natural composite composed with banana peel and high-density polyethylene were studied. It was noted that removing the lignin present in the banana peel, the fiber introduces a significant improvement in thermal resistance. The preparation of composite was made with a ratio of 5% and 10% of reinforcement in comparison with polymeric matrix mass. Composites were thermally, mechanically and microscopically characterized. The addition of fiber in the polymer increased the mechanical strength of the composite. The fiber surface treatment with distilled water removed the amorphous material present in the fibers, improving significantly thermal stability and increasing crystallinity of the celullose. The addition of 5% fiber in mass to the polymer increased significantly the tensile strength and elasticity modulus for the composite. With 10% of fiber addiction there were also an improvement when compared with pure HDPE, but when compared with 5% composite the mechanical properties are slightly lower. This may be due to the fiber particle size, which are small and eventually become a hub of tension ... (Complete abstract click electronic access below)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia (Horticultura) - FCA

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Introdução: a irrigação é um procedimento importante durante o tratamento do canal radicular, auxiliando na limpeza de áreas do sistema de canais radiculares que não são alcançadas diretamente por instrumentos. Objetivo: o objetivo desse estudo foi avaliar a biocompatibilidade e a capacidade de desinfecção de nanopartículas de prata em dispersão, em comparação ao hipoclorito de sódio a 2,5%. Métodos: trinta ratos receberam, individualmente, quatro tubos de dentina infectados e não infectados, irrigados com dispersão de nanopartículas de prata 47ppm e 23ppm, hipoclorito de sódio a 2,5% e solução salina. Dezesseis ratos receberam um tubo de dentina infectada e um tubo de dentina não infectada como grupo controle. Após 7 e 30 dias, os animais foram sacrificados, os tubos e o tecido circundante foram removidos e preparados para análise em microscopia de luz. Avaliações qualitativas e quantitativas das reações foram realizadas. Resultados: todas as soluções em tubos não infectados causaram reações leves em 30 dias. Todas as soluções em tubos infectados causaram reações graves em 7 dias e leves em 30 dias. As respostas foram semelhantes às do grupo controle não infectado, mas melhores do que o grupo controle infectado. Conclusões: foi possível concluir que nanopartículas de prata em dispersão são biocompatíveis e podem atuar na desinfecção de tubos contaminados, especialmente em concentrações de 23ppm.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)