15 research outputs found

    Evaluation of a simplified model for estimating energy balance in broilers production housing

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    The simulation of poultry house thermal behavior with and without Adiabatic Evaporative Cooling (SRAE) allows the decision makers to evaluate the economical feasibility and the installation costs of a poultry production business. The first step in this research investigation was test the thermal behavior model developed by Gates et al. (1995) for broiler houses in the United States based on the hypothesis that this model, using climatized sheds, as proposed by the authors, could be used under Brazilian conditions. The model is suitable for the proposed objective in the form proposed by Gates et al. (1995) for poultry houses with an elevated mass air flow rate (120.8 kg air s -1 or higher). A correction factor referring to a series of heat sources not included in the model, or the inclusion of these sources, is necessary for poultry houses without a high mass air flow.A simulação do comportamento térmico de galpões avícolas com e sem Sistemas de Resfriamento Adiabáticos Evaporativos (SRAE) permite aos tomadores de decisão avaliarem a viabilidade econômica e os custos da instalação de um empreendimento na avicultura de corte. Para operacionalização desta investigação, o primeiro passo foi a execução do teste do modelo de comportamento térmico desenvolvido por Gates et al. (1995) para galpões avícolas nos Estados Unidos, com base na hipótese de que este modelo, utilizando-se galpões climatizados, como sugerido pelos autores, possa ser usado em condições brasileiras. O modelo se mostrou adequado para o objetivo previsto, na forma indicada por Gates et al. (1995) para galpões com vazão mássica do ar elevada, (120,8 kg de ar por segundo ou maior). É necessário um fator de correção referente a uma série de fontes de calor desprezada pelo modelo para galpões sem uma grande vazão mássica, ou a inclusão dessas fontes

    Effects of Resistance Exercise on Endothelial Progenitor Cell Mobilization in Women

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    This study aimed to determine the effect of a single bout of resistance exercise at different intensities on the mobilization of circulating EPCs over 24 hours in women. In addition, the angiogenic factors stromal cell-derived factor 1 (SDF-1α), vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1-alpha (HIF-1α) and erythropoietin (EPO) were measured as potential mechanisms for exercise-induced EPCs mobilization. Thirty-eight women performed a resistance exercise session at an intensity of 60% (n = 13), 70% (n = 12) or 80% (n = 13) of one repetition maximum. Each session was comprised of three sets of 12 repetitions of four exercises: bench press, dumbbell curl, dumbbell squat, and standing dumbbell upright row. Blood was sampled at baseline and immediately, 6 hours, and 24 hours post-exercise. Circulating EPC and levels of VEGF, HIF-1α and EPO were significantly higher after exercise (P \u3c 0.05). The change in EPCs from baseline was greatest in the 80% group (P \u3c 0.05), reaching the highest at 6 hours post-exercise. The change in EPCs from baseline to 6 hours post-exercise was correlated with the change in VEGF (r = 0.492, P = 0.002) and HIF-1α (r = 0.388, P = 0.016). In general, a dose-response relationship was observed, with the highest exercise intensities promoting the highest increases in EPCs and angiogenic factors

    Cytotoxicity assessment of endodontic sealers: metabolic activity, morphology and chromosomal alterations

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    Introduction: Endodontic treatment aims to eliminate infection of the root canals and fill the dental pulp space, being, the obturation of root canals an important step. The study of the toxicity/biocompatibility of the sealers used to fill the root canals is crucial since they are applied into direct contact with periradicular tissues.There are several types of sealers, categorized according to their main chemical constituents. The aim of this study was to evaluate the cytotoxicity of three root canal sealers, AH Plus, Bio MTA+ and Bio C, on immortalized human gingival fibroblasts. Methods: To study the cytotoxicity of the sealers we performed a Methyltetrazolium (MTT) assay, a study of cell's morphology and a cytogenetic study. Cells were placed in contact with material-conditioned media, for 24 h, at three different concentrations (1, 10 and 100 mg/ml) for the MTT assay. Cell morphology and cytogenetic studies were performed at 100 mg/ml. Cells in normal culture medium were analyzed as control group. Results: MTT assay revealed a cytotoxic effect of Bio MTA+ and Bio C with a growing decrease of metabolic activity with increasing compound concentration, reaching 50% with 100 mg/ml. Regarding the cells morphology, Bio C was the compound that showed a more drastic effect, with a decrease in cell confluence and several morphological changes. AH Plus and Bio MTA+ did not seem to affect the cell confluence, however morphology changes were observed, as compromised cell membranes and loss of cell content. Cytogenetic study was thus far only performed with AH Plus. Since there was a severe decrease of mitotic index after treatment, it was not yet possible to obtain sufficient metaphases, even after several cytogenetic harvesting procedures, but, so far, no relevant structural or numerical changes were observed. Discussion: This preliminary study allowed us to verify that these root canal sealers exhibit some cytotoxicity, depending on the concentration used. Although more studies are still needed, this work could be important to both, help in the selection of the most appropriate compounds for clinical practice and to determine the maximum recommended amounts of each sealer.info:eu-repo/semantics/publishedVersio

    La renovación de la palabra en el bicentenario de la Argentina : los colores de la mirada lingüística

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    El libro reúne trabajos en los que se exponen resultados de investigaciones presentadas por investigadores de Argentina, Chile, Brasil, España, Italia y Alemania en el XII Congreso de la Sociedad Argentina de Lingüística (SAL), Bicentenario: la renovación de la palabra, realizado en Mendoza, Argentina, entre el 6 y el 9 de abril de 2010. Las temáticas abordadas en los 167 capítulos muestran las grandes líneas de investigación que se desarrollan fundamentalmente en nuestro país, pero también en los otros países mencionados arriba, y señalan además las áreas que recién se inician, con poca tradición en nuestro país y que deberían fomentarse. Los trabajos aquí publicados se enmarcan dentro de las siguientes disciplinas y/o campos de investigación: Fonología, Sintaxis, Semántica y Pragmática, Lingüística Cognitiva, Análisis del Discurso, Psicolingüística, Adquisición de la Lengua, Sociolingüística y Dialectología, Didáctica de la lengua, Lingüística Aplicada, Lingüística Computacional, Historia de la Lengua y la Lingüística, Lenguas Aborígenes, Filosofía del Lenguaje, Lexicología y Terminología

    Endothelial Progenitor Cell Response to Acute Multicomponent Exercise Sessions with Different Durations

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    It is widely accepted that exercise training has beneficial effects on vascular health. Although a dose-dependent relation has been suggested, little is known about the effects of different exercise durations on endothelial markers. This study aimed to assess the effect of single exercise sessions with different durations in the circulating levels of endothelial progenitor cells (EPCs) and endothelial cells (CECs) among adults with cardiovascular risk factors. Ten participants performed two multicomponent exercise sessions, one week apart, lasting 30 and 45 min (main exercise phase). Before and after each exercise session, blood samples were collected to quantify EPCs and CECs by flow cytometry. The change in EPCs was significantly different between sessions by 3.0% (95% CI: 1.3 to 4.7), being increased by 1.8 ± 1.7% (p = 0.009) in the 30 min session vs. -1.2 ± 2.0% (p > 0.05) in the 45 min session. No significant change was observed in CECs [-2.0%, 95%CI: (-4.1 to 0.2)] between the sessions. In conclusion, a multicomponent exercise session of 30 min promotes an acute increase in the circulating levels of EPCs without increasing endothelial damage (measured by the levels of CECs) among adults with cardiovascular risk factors

    Maximal Exercise Improves the Levels of Endothelial Progenitor Cells in Heart Failure Patients

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    The impact of exercise on the levels of endothelial progenitor cells (EPCs), a marker of endothelial repair and angiogenesis, and circulating endothelial cells (CECs), an indicator of endothelial damage, in heart failure patients is largely unknown. This study aims to evaluate the effects of a single exercise bout on the circulating levels of EPCs and CECs in heart failure patients. Thirteen patients with heart failure underwent a symptom-limited maximal cardiopulmonary exercise test to assess exercise capacity. Before and after exercise testing, blood samples were collected to quantify EPCs and CECs by flow cytometry. The circulating levels of both cells were also compared to the resting levels of 13 volunteers (age-matched group). The maximal exercise bout increased the levels of EPCs by 0.5% [95% Confidence Interval, 0.07 to 0.93%], from 4.2 103 1.5 103% to 4.7 103 1.8 103% (p = 0.02). No changes were observed in the levels of CECs. At baseline, HF patients presented reduced levels of EPCs compared to the age-matched group (p = 0.03), but the exercise bout enhanced circulating EPCs to a level comparable to the age-matched group (4.7 103 1.8 103% vs. 5.4 103 1.7 103%, respectively, p = 0.14). An acute bout of exercise improves the potential of endothelial repair and angiogenesis capacity by increasing the circulating levels of EPCs in patients with heart failure
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