917 resultados para Exercise - Physiological aspects - Measurement


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Introduction: The practice of moderate-intensity exercise can reduce the risk of infections and improve metabolic aspects of the person. Objective: To investigate the effects of aerobic physical training on endocrine and metabolic aspects, bone and immune systems. Methods: Twenty Wistar rats were divided in two groups: sedentary (SG) and trained group (TG). Training program consisted in swimming, 6 weeks, supporting a workload corresponding to 5% of body weight. At the end of the experiment, were performed counting total and differential leukocyte count and hematocrit. After training period, were analyzed glucose, total protein, triglycerides, cholesterol, liver and muscle samples for the determination of the levels of glycogen, and determination of the tibia length and bone area. All dependent variables were analyzed by one-way analysis of variance (ANOVA) and a significance level of P < 0.05 was used for all comparisons. Results: Hematocrit (%) analyzed showed a significant difference, with higher values ffor TG (54.63 ± 1.41) than for the SG (49.5 ± 1.65). The total leukocyte count was not significantly different, as there was no difference in the differential count. Total cholesterol showed significant decrease in TG (TG = 68.27 ± 13.71 mg/dL; SG = 94.44 ± 28.09), the total protein levels also showed significant reduction (TG = 7.3 ± 0.40 g/dL; SG = 7.74 ± 0.36 g/dL) glucose levels and triglyceride showed no significant differences. The bone length showed significant difference (TG = 40±0.14 mm; SG = 42.10 ± 0.12mm). Tibial area showed a lower value for TG (1.53 ± 0.12cm2) than for SG (1.67 ± 0.18cm2); however, the difference was not statistically significant. Conclusion: It can be concluded that aerobic exercise training is able to produce some unique physiological changes in young rats. There is also the need to prescribe exercises that meet the particular maturational stage of development.

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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This paper reports the results that are part of a series of experiments designed to evaluate aspects of the spatial resolution of the visual system of the opossum, Didelphis marsupialis aurita. This nocturnal marsupial presents a well-developed eye, displaying features that reflect specialization for operation at low levels of luminosity. The species was shown to be slightly myopic, a feature that may prove to be valuable because of the increased depth of field. Opossum visual acuity has been previously evaluated by means of determining the Contrast Sensitivity Function (CSF). The results indicate rather poor visual acuity compared with other nocturnal animals. In this paper, we describe the results obtained for the optical quality of the opossum's eye using a single-pass method. The results suggest that the opossum's optical system is capable of forming images that can be resolved when separated by an angular distance on the order of 6 minutes of arc.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Introduction: The practice of moderate-intensity exercise can reduce the risk of infections and improve metabolic aspects of the person. Objective: To investigate the effects of aerobic physical training on endocrine and metabolic aspects, bone and immune system. Methods: Twenty Wistar rats were divided in two groups: sedentary (GS) and trained group (TG). Training program consisted in swimming, 6 weeks, supporting a workload corresponding to 5% of body weight. At the end of the experiment, were performed counting total and differential leukocyte count and hematocrit. After training period, were analyzed glucose, total protein, triglycerides, cholesterol, liver and muscle samples for the determination of the levels of glycogen, and determination of the tibia length and bone area. All dependent variables were analyzed by one-way analysis of variance (ANOVA) and a significance level of P < 0.05 was used for all comparisons. Results: Hematocrit (%) analyzed showed a significant difference, with higher values for TG (54.63 +/- 1.41) than for the GS (49.5 +/- 1.65). The total leukocyte count was not significantly different, as there was no difference in the differential count. Total cholesterol showed significant decrease in GT (GT = 68.27 +/- 13.71 mg/dL; GS = 94.44 +/- 28.09), the total protein levels also showed significant reduction (GT = 7.3 +/- 0,40 g/dL; GS = 7.74 +/- 0.36 g/dL) glucose levels and triglyceride showed no significant differences. The bone length showed a significant difference (GT = 40 +/- 0.14 mm; CG = 42.10 +/- 0.12mm). The tibial area showed the lowest value for the GT (1.53 +/- 0.12cm(2)) than for the GS (1.67 +/- 0.18cm(2)) however the difference was not statistically significant. Conclusion: It can be concluded that aerobic exercise training is able to produce some unique physiological changes in young rats. There is also the need to prescribe exercises that meet the particular maturational stage of development.

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One of the main objectives of the Spanish and Portuguese-Speaking Group of the International Society for Forensic Genetics (GHEP-ISFG) is to promote and contribute to the development and dissemination of scientific knowledge in the area of forensic genetics. Due to this fact, GHEP-ISFG holds different working commissions that are set up to develop activities in scientific aspects of general interest. One of them, the Mixture Commission of GHEP-ISFG, has organized annually, since 2009, a collaborative exercise on analysis and interpretation of autosomal short tandem repeat (STR) mixture profiles. Until now, three exercises have been organized (GHEP-MIX01, GHEP-MIX02 and GHEP-MIX03), with 32, 24 and 17 participant laboratories respectively. The exercise aims to give a general vision by addressing, through the proposal of mock cases, aspects related to the edition of mixture profiles and the statistical treatment. The main conclusions obtained from these exercises may be summarized as follows. Firstly, the data show an increased tendency of the laboratories toward validation of DNA mixture profiles analysis following international recommendations (ISO/IEC 17025: 2005). Secondly, the majority of discrepancies are mainly encountered in stutters positions (53.4%, 96.0% and 74.9%, respectively for the three editions). On the other hand, the results submitted reveal the importance of performing duplicate analysis by using different kits in order to reduce errors as much as possible. Regarding the statistical aspect (GHEP-MIX02 and 03), all participants employed the likelihood ratio (LR) parameter to evaluate the statistical compatibility and the formulas employed were quite similar. When the hypotheses to evaluate the LR value were locked by the coordinators (GHEP-MIX02) the results revealed a minor number of discrepancies that were mainly due to clerical reasons. However, the GHEP-MIX03 exercise allowed the participants to freely come up with their own hypotheses to calculate the LR value. In this situation the laboratories reported several options to explain the mock cases proposed and therefore significant differences between the final LR values were obtained. Complete information concerning the background of the criminal case is a critical aspect in order to select the adequate hypotheses to calculate the LR value. Although this should be a task for the judicial court to decide, it is important for the expert to account for the different possibilities and scenarios, and also offer this expertise to the judge. In addition, continuing education in the analysis and interpretation of mixture DNA profiles may also be a priority for the vast majority of forensic laboratories. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

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

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The development of polymeric blends to be used as matrices for bone regeneration is a hot topic nowadays. In this article we report on the blends composed by corn starch and poly(vinylidene fluoride), PVDF, or poly(vinylidene fluoride-trifluoroethylene), P(VDF-TrFE), to obtain biocompatible materials. Blends were produced by compressing/annealing and chemically/structurally characterized by micro-Raman scattering and Fourier transform infrared (FTIR) absorption spectroscopies, dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM), besides in vivo study to evaluate the tissue response. Vibrational spectroscopy reveals no chemical interaction between the polymers and starch, absence of material degradation due to compressing/annealing process or organism implantation, and maintenance of a and ferroelectric crystalline phases of PVDF and P(VDF-TrFE), respectively. As a consequence of absence of interaction between polymers and starch, it was possible to identify by SEM each material, with starch acting as filler. Elastic modulus (E') obtained from DMA measurement, independent of the material proportion used in blends, reaches values close to those of cancellous bone. Finally, the in vivo study in animals shows that the blends, regardless of the composition, were tolerated by cancellous bone. (C) 2013 Elsevier B.V. All rights reserved.

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Gastrointestinal problems are common, especially in endurance athletes, and often impair performance or subsequent recovery. Generally, studies suggest that 30-50 % of athletes experience such complaints. Most gastrointestinal symptoms during exercise are mild and of no risk to health, but hemorrhagic gastritis, hematochezia, and ischemic bowel can present serious medical challenges. Three main causes of gastrointestinal symptoms have been identified, and these are either physiological, mechanical, or nutritional in nature. During intense exercise, and especially when hypohydrated, mesenteric blood flow is reduced; this is believed to be one of the main contributors to the development of gastrointestinal symptoms. Reduced splanchnic perfusion could result in compromised gut permeability in athletes. However, although evidence exists that this might occur, this has not yet been definitively linked to the prevalence of gastrointestinal symptoms. Nutritional training and appropriate nutrition choices can reduce the risk of gastrointestinal discomfort during exercise by ensuring rapid gastric emptying and the absorption of water and nutrients, and by maintaining adequate perfusion of the splanchnic vasculature. A number of nutritional manipulations have been proposed to minimize gastrointestinal symptoms, including the use of multiple transportable carbohydrates, and potentially the use of nutrients that stimulate the production of nitric oxide in the intestine and thereby improve splanchnic perfusion. However, at this stage, evidence for beneficial effects of such interventions is lacking, and more research needs to be conducted to obtain a better understanding of the etiology of the problems and to improve the recommendations to athletes.

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