222 resultados para aquatic humic substances
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The yolk protein precursor, vitellogenin (Vg), in bees is synthesized in the fat body trophocytes, delivered to the hemolymph and ultimately absorbed from there during the vitellogenic phase of oocytes in the active ovary. The routes tracing the material exchange that occurs between the trophocytes and the hemolymph, in addition to the transportation from the hemolymph to the ovarian follicles, were marked by alkaline phosphatase and lanthanum nitrate (LN). Active ovaries from nurse workers and physogastric queens, as well as inactive ovaries of virgin queens, were examined by transmission electron microscopy. The LN permitted better visualization of the routes of exchanges between the organs and the hemolymph. Both methods demonstrate the apparent differences between the phases of the ovary and the bee caste. In inactive ovaries of the virgin queens, the routes from the follicular epithelium to the oocyte remain closed; conversely, they are open in active ovaries of the nurse workers and physogastric queens. The differences between the methods and classes of bees are discussed. © The Author 2013. Published by Oxford University Press [on behalf of The Japanese Society of Microscopy]. All rights reserved.
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Background and Purpose: The evidence of the benefits from regular physical activity to hypertensives is based on dry land training studies. Therefore, the aim of this study is to compare the effect of aquatic exercise with dry land training on hypertensive women. Methods: This is a randomized controlled study with 52 post-menopausal hypertensive women. The patients were randomly allocated in three groups: water aerobic training group (n=19), dry land aerobic training group (n=19) and a non-intervention control group (n=14). The training protocol was performed by 12weeks. Results: There were no differences among the three groups concerning basal blood pressure (BP) and biochemical variables. In water group, there was a statistically significant reduction of systolic BP from 136±16mmHg at zero week to 124±18mm Hg at 11th week and 124±15mmHg at 12th week. In dry land training group, there was a statistically significant reduction of systolic BP from 138±15mmHg at zero week to 125±10mmHg at 7th week, 127±10mmHg at 10th week and 126±9mmHg at 12th week. The control group presented no change in any of the assessed variables. No changes were carried out in any antihypertensive medications during study. Discussion: This is a randomized controlled study that demonstrates the antihypertensive efficacy of aerobic aquatic exercise. © 2013 John Wiley & Sons, Ltd.
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The ecotoxicology of nano-TiO2 has been extensively studied in recent years; however, few toxicological investigations have considered the photocatalytic properties of the substance, which can increase its toxicity to aquatic biota. The aim of this work was to evaluate the effects on fish exposed to different nano-TiO2 concentrations and illumination conditions. The interaction of these variables was investigated by observing the survival of the organisms, together with biomarkers of biochemical and genetic alterations. Fish (Piaractus mesopotamicus) were exposed for 96h to 0, 1, 10, and 100mg/L of nano-TiO2, under visible light, and visible light with ultraviolet (UV) light (22.47J/cm2/h). The following biomarkers of oxidative stress were monitored in the liver: concentrations of lipid hydroperoxide and carbonylated protein, and specific activities of superoxide dismutase, catalase, and glutathione S-transferase. Other biomarkers of physiological function were also studied: the specific activities of acid phosphatase and Na,K-ATPase were analyzed in the liver and brain, respectively, and the concentration of metallothionein was measured in the gills. In addition, micronucleus and comet assays were performed with blood as genotoxic biomarkers. Nano-TiO2 caused no mortality under any of the conditions tested, but induced sublethal effects that were influenced by illumination condition. Under both illumination conditions tested, exposure to 100mg/L showed an inhibition of acid phosphatase activity. Under visible light, there was an increase in metallothionein level in fish exposed to 1mg/L of nano-TiO2. Under UV light, protein carbonylation was reduced in groups exposed to 1 and 10mg/L, while nucleus alterations in erythrocytes were higher in fish exposed to 10mg/L. As well as improving the understanding of nano-TiO2 toxicity, the findings demonstrated the importance of considering the experimental conditions in nanoecotoxicological tests. This work provides information for the development of protocols to study substances whose toxicity is affected by illumination conditions. © 2013 Elsevier B.V..
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC
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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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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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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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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)