986 resultados para Acetato de chumbo


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The concentration of metal pollutants such as lead (Pb), has grown and developed in populated areas due to pollution and other human activities. Consequently, the potential for achieve this element food chain has also increased. Lead is very toxic to humans, especially to children, and exposure to lead can cause adverse health effects mainly on human nervous system, bone marrow and kidneys, interfering with chromosomal or genetic processes. This paper presents an overview of the main aspects related to environmental contamination by lead from battery plants. The assessment of an area contaminated by lead in Bauru-SP next a battery factory was reported in this work as well as the entire history of monitoring, classification and application of processes applied by CETESB since 2002. Analyzing the issue in its economic aspects, we found that the degradation of the environment is directly related to the development model adopted by the capitalist system, which is based on the law of supply and demand for products and services. The data presented indicate that Brazil still needs a broader policy where government agencies, industries and population through awareness can be united for the same purpose: to preserve life

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O acetato de dexametasona (DXM) é um glicocorticoide com eficácia antiinflamatória e imunossupressora, sendo utilizado nas doenças autoimunes. Sua ação antiinflamatória advém da inibição do acúmulo de células (macrófagos, linfócitos e neutrófilos) na área da inflamação, inibindo também a liberação de mediadores da inflamação como interferon-γ e TNF-α. Já a atividade imunossupressora é alcançada com a redução do concentrado de linfócitos e inibição da síntese e/ou liberação de interleucinas. Porém o uso contínuo do DXM ocasiona uma série de efeitos colaterais sistêmicos, sendo interessante sua aplicação tópica para viabilizar a promoção do aumento da liberação e a estabilização dos níveis plasmáticos do fármaco. Sistemas nanoestruturados como microemulsões (ME) e os cristais líquidos (CL) vêm sendo estudados como novos sistemas de liberação, pois além de se comportarem como reservatórios de fármacos também possibilitam o aumento da estabilidade e da solubilidade dos princípios ativos. Os objetivos deste trabalho foram desenvolver e caracterizar sistemas micro e nanoestruturados, com intuito de incorporar DXM e avaliar sua permeação cutânea in vitro. Foram desenvolvidos sistemas utilizando água, silicone (DC® 193C fluido) e polioxietileno-20-oleil éter (Brij® 98). Os 36 pontos do diagrama de fases foram avaliados, sendo elaboradas formulações com diferentes proporções de água, óleo e tensoativo, sendo possível delimitar regiões como: sistemas transparentes de alta viscosidade (STAV), sistemas transparentes de baixa viscosidade (STBV), sistemas líquido-transparentes (SLT), emulsão viscosa (EV) e emulsão líquida (EL). Três formulações foram selecionadas para os ensaios de caracterização, fixando-se a concentração de tensoativo (T) em 40% e variando-se as concentrações de água e de silicone, denominadas A, B e C. As análises de microscopia de luz polarizada ...

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Located in Apiaí, Vale do Ribeira, southern region of São Paulo state, the Usina do Calabouço areas (CIEM / CPRM) and Morro do Ouro (Parque Municipal do Morro do Ouro), were targeted for stud ies due to its old buildings, respectively a foundry in lead ore, called Experimental de Chumbo e Prata (Usina Calabouço), and a gold mine with processing plant of the gold-bearing ore produced there. Nowadays, the areas are used for public visitation, and in both places the rests of the buildings remains. Particularly in the CIEM/CPRM, due to the materials witch was produced before, it can suggest the existence of anomalous amounts of the involved metals (CIEM / CPRM) and possible contaminations by chemical products used in the improvement of the auriferous ore (P. M. Morro do Ouro). These potential contamination were confirmed with geochemical survey of soils and current sediments accomplished in both areas, for the elements arsenic, cadmium, lead, copper, mercury, silver and zinc, which were used as parameters guiding values for soil and groundwater the state of São Paulo (CETESB), and watershed values stipulated by CPRM (poor, background and anomalous), in it rising geochemistry during Folha Apiaí's execution (SG-22-X-B-V).

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Plumbism is considered the oldest occupational disease. Among the pathophysiological effects associated with lead (Pb) are cardiovascular disorders. Many diseases that develop later in life are determined during the early stages of life, under the influence of exposure and preferred diet of the mother. Still, one should consider that many environmental contaminants at levels not harmful can determine pathophysiological processes if physical or chemical stressors and/or pathological conditions are present. In this context, the intrauterine malnutrition may represent an additional risk factor in exposure to Pb during pregnancy and lactation. For these reasons, the objective of this study was to evaluate the cardiovascular risk of weaned rats that have suffered perinatal exposure to Pb and intrauterine malnutrition, alone or in combination. After mating, female rats were divided into control (ctrl, ad libitum), food restriction (RA, the same diet 50% of consumption in the control group during pregnancy), exposed to Pb (500 ppm Pb in drinking water during pregnancy and lactation) and association (As, received the last two procedures in combination). Cumulative concentration-effect curves (CECs) to CaCl2 and noradrenaline (NA) were obtained in rings with and without endothelium of the same thoracic aorta from male weaned rats (23-25 days old). Maternal weight, litter weight, weight and number of pups at birth, anogenital distance, arterial blood pressure (ABP) and weight of tissues (kidney, liver, aorta, left ventricle) were evaluated. Changes in vascular reactivity were assessed by the maximum response (MR) and 50% effective concentration (EC50). Data were presented as mean ± SEM. Statistical analysis was performed by multifactorial analysis of variance and Tukey's post test. Body weight of dams did not differ between the experimental groups, except on the...(Complete abstract click electronic access below)

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To verify the levels of concentration of some heavy metals in fishes from Sorocaba river (São Paulo, Brazil) and evaluate if this contamination offers health risks to the fishermen, 63 samples of fishes collected from four points along the river were studied for cadmium, lead, chromium, nickel and mercury, with emphasis in this last, since it is the most toxic and most probable as a fish contaminant. Analyzing muscle samples by cold vapor atomic absorption spectrometry it was shown that the fishes are not contaminated. None of the five metals studied were present in prohibitive level and the fishes could be judged secure for human consume. It was also analyzed data from four years of cadmium, lead, chromium, nickel and mercury monitoring made by CETESB, from 1997 to 2000, in water from the main rivers of the State of São Paulo. The study pointed out that the majority of the monitored rivers still present contamination by those metals in a level that requires an improvement of the pollution control actions.

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Cu(II), Cd(II), Mn(II) AND Ni(II). Cellulose acetate polymeric membranes had been prepared by a procedure of two steps, combining the method of phase inversion and the technique of hydrolysis-deposition. The first step was the preparation of the membrane, and together was organomodified with tetraethylortosilicate and 3-aminopropyltrietoxysilane. Parameters that exert influence in the complexation of the metallic ion, as pH, time of complexation, metal concentration, had been studied in laboratory using tests of metal removal. The membranes had presented resistance mechanics and reactivity to cations, being able to be an alternative for the removal, daily pay-concentration or in the study of the lability of metals complexed.

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Pós-graduação em Ciência dos Materiais - FEIS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The objective of this study objective was to evaluate the selectivity of pre-emergence applications the herbicide clomazone cotton seeds treated with dietholate and zinc acetate. The 4 x 2 factorial arrangement was adopted (4 seed treatment methods and 2 clomazone dosages), distributed in a randomized block design with 4 repetitions. In treatments where dietholate and zinc acetate were applied, rates of 0.4 kg ha(-1) and 8 ml per kg of seeds were used respectively. The clomazone rates used refer to 0.8 and 1.0 kg ha(-1). The cotton cultivar used was the Fiber Max 966 LL. Independent of treatment, all seeds were treated with tiametoxam insecticide and fludioxonil + metalaxyl-M fungicide at rates of 2.24 and 0.08 + 0.03 g per kg of seed, respectively, to control pests early and limit losses caused by pathogens in germination and seedling emergence. Dietholate and zinc acetate treatment had greater initial effect on cotton plants at 21, 30 and 45 days after application. In phytointoxication symptoms were observed for treatment with dietholate and zinc acetate during the evaluation periods. Seeds treated with dietholate, dietholate and zinc acetate or zinc acetate alone provided a higher number of bolls and seed cotton production compared to the control.

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Pós-graduação em Engenharia Civil e Ambiental - FEB