895 resultados para Superfícies seletivas em frequência
Resumo:
Introdução: A variabilidade da frequência cardíaca (VFC) descreve o comportamento dos intervalos RR que está relacionado às ações do sistema nervoso autônomo (SNA) sobre o nódulo sinusal. Essa pode ser influenciada por diversos fatores dentre eles a obesidade, doença de etiologia multifatorial definida como um acúmulo excessivo de gordura corporal. Objetivo: Avaliar em jovens obesos com idade entre 18 e 23 anos o comportamento autonômico cardíaco, durante o repouso, por meio da análise linear e não linear dos índices da VFC bem como associá-lo a eventos de desconforto músculoesquelético influenciados ou não pela prática regular de exercício físico nessa população. Metodologia: Para a realização deste estudo foram analisados dados de 68 voluntários jovens, de ambos os sexos, distribuídos de forma não randomizada em dois grupos: o G1 constituído por 32 obesos, 20,21 ± 1,66 anos e o G2 por 36 não obesos, 20,8 ± 1,47 anos sendo considerado como critério de classificação dos voluntários o índice de massa corpórea (IMC). O protocolo experimental consistiu da captação da frequência cardíaca batimento a batimento, por meio de uma cinta de captação fixada no tórax do voluntário juntamente com um receptor de frequência cardíaca fixado no punho. Para esta captação o voluntário foi orientado a permanecer em repouso na posição de decúbito dorsal sobre um colchonete, durante 30 minutos, com a respiração espontânea. Além disso, foram aplicados dois questionários, ou seja: versão curta do International Physical Activity Questionaire (IPAQ) - Questionário Internacional de Atividade Física, a fim de classificar o nível de atividade física e o Questionário Nórdico, para detectar eventuais sintomas osteomusculares decorrentes das atividades de vida diária e/ou atividades física. Os índices da VFC analisados foram: análise linear... (Resumo completo, clicar acesso eletrônico abaixo)
Resumo:
Indivíduos imunocomprometidos possuem maior risco de desenvolver linfomas associados ao EBV. A detecção desse vírus em sangue periférico e a determinação de sua carga viral podem ter importância na evolução clínica de indivíduos portadores do HIV. Foram avaliadas 156 amostras de pacientes HIVpositivos pela reação em cadeia da polimerase em tempo real (qPCR) para detecção e quantificação da carga viral do EBV. 123/156 (78,8%) casos apresentaram carga viral detectável para o EBV, sendo que a carga viral média foi de 6,9x10-3 cópias de EBV/célula. Foi detectada elevada carga viral do EBV em indivíduos com falha terapêutica ou sem HAART (p =0,0076), em coinfectados pelos EBVs 1 e 2 (p=0,0205), em pacientes com altas cargas de HIV (rho=0,27614, p=0,0005) e longos períodos de infecção pelo HIV (rho= 0,24164, p =0,0026) e os que apresentavam altos níveis de linfócitos T CD8 + (rho=0,19286, p =0,0159). A amplificação do gene EBNA-2 para realização da tipagem viral foi possível em 95/123 (77,2%) amostras, das quais 72 (75,8%) revelaram infecção pelo EBV-1, 9 (9,5%) pelo EBV-2 e 14 (14,7%) apresentavam coinfecção entre os EBVs 1 e 2. Esses dados estão de acordo com a literatura visto que o tipo 1 é predominante em países ocidentais e 70,0% da coorte era composta por indivíduos caucasianos e heterossexuais. A maioria dos pacientes que apresentaram coinfecção pelos EBVs 1 e 2 tiveram contagem de linfócitos T CD4 + entre 200 e 499 células/μL de sangue segundo classificação CDC (p =0,0272). Quanto a analise do gene BNLF-1, a amplificação foi possível em 99/123 (80,5%). Desses 50/99 (50,5%) apresentavam a deleção de 30pb no gene, enquanto 49/99 (49,5%) não a possuíam. Em conjunto, os resultados obtidos evidenciam deterioração do sistema imunitário, caracterizada...(Resumo completo, clicar acesso eletrônico abaixo)
Resumo:
In this work we report the development of a tube amplifier built to be used in magnetic probe diagnostic of plasma. The probe is used to measure the magnetic field in the theta-pinch system presently running in our university. We present the calculations and procedures to determine the configuration of circuits and specify the components of the power supply, the preamp stage and the power stage. The circuit configuration and the characteristics of the components was obtained. A representative model of the system behavior gave the transfer function of the amplifier. Theoretical predictions of frequency response and the feedback effects were compared to the experimental values and showed very good agreement. The amplifier works between a frequency bandwidth of 20 an 30 kHz and supply a maximum power of 12 W
Resumo:
Introduction: The triangular index and the Poincaré plot (or Lorenz plot) are the best known indexes obtained from geometric methods. The triangular index (TINN, RRtri) represent the global variability of the subject and SD1, which reflects the parasympathetic component, SD2, index of global variability and its relationship (SD1/SD2) are obtained from the Poincaré plot. Despite the literature showing changes in the cardiovascular system during and after the resistance exercise (RE), aspects related to autonomic modulation of heart against these conditions have not been explored yet, so it is important to evaluate this behavior. Objectives: Analyze the acute effects of RE on the cardiac autonomic modulation during recovery (REC) through analysis of geometric indices of heart rate variability (HRV), applied with different intensities and muscle groups in healthy and active young. Methods: Were evaluated 24 young, 22.25 ± 2.4 years and 24.47 ± 3.08 kg/m2, underwent an experimental protocol of five stages, in the first stage was conducted a test of one maximum repetition (1RM) in upper limbs (UL) and lower limb (LL), and the following steps were initiated interventions to 40 (E) and 80% (F) of 1RM. Considered for HRV analysis the periods: baseline and immediately after exercise, both in supine... (Complete abstract click electronic access below)
Resumo:
Fracture surfaces express sequences of events of energy release with crack propagation in metal alloys, the evolution of topographic features can indicate the lines of load action, failures during the use or processing. The quantitative fractography is an important tool in the study of fracture surfaces, because it allows their interpretation and characterization. In order to evaluate the effectiveness of the characterization of fracture surfaces grounded on concepts such as selfsimilarity and self-affinity, it used the 15-5PH steel that was characterized by metallographic and tensile tests. The metallography allows the microstructural characterization of this steel and proved the presence of the martensite phase in the slats form and a fine-grained, both in the radial and in the axial direction of the dowel. The tensile test (ASTM E8) of this material allowed the determination of the mechanical properties, so based on the obtained results it was possible to affirm that the 15-5PH steel has high mechanical properties and a good stretch. Besides, the specimens also underwent testing of crack propagation, standardized by ASTM E647-00, thus it was obtained the fracture surfaces for characterization under monofractal and multifractal approaches. In front of all the exposed it was possible to conclude that in all measurements the correlation between the crack tip position and the fractal dimension was established in accordance with changes in the thickness and in the fracture micromechanisms presents. Furthermore, the multifractal approach was more sensitive to these variations allowing a more detailed characterization of the morphology
Resumo:
The representation of real objects in virtual environments has applications in many areas, such as cartography, mixed reality and reverse engineering. The generation of these objects can be performed in two ways: manually, with CAD (Computer Aided Design) tools, or automatically, by means of surface reconstruction techniques. The simpler the 3D model, the easier it is to process and store it. Multiresolution reconstruction methods can generate polygonal meshes in different levels of detail and, to improve the response time of a computer program, distant objects can be represented with few details, while more detailed models are used in closer objects. This work presents a new approach to multiresolution surface reconstruction, particularly interesting to noisy and low definition data, for example, point clouds captured with Kinect sensor
Resumo:
The genus Corydoras, the highest among the Siluriformes, Callichthyidae is owned by the family, consisting of 177 valid species and widely distributed in cis-Andean portion of South America How striking feature has two longitudinal series of dermal plates covering almost the entire body. Cytogenetic studies in Callichthyidae show many chromosomal rearrangements, including events of polyploidy in their evolutionary history, particularly the genus Corydoras, in which the variation is the diploid number of 2n = 40 to 2n = 134 chromosomes. The absence of information on the frequency of chromosomes in the group Bs motivated this work with the species Corydoras aeneus. A population from the Tietê River basin in Ribeirão Claro (subbasin Corumbataí - Rio Claro, SP) was sampled a total of 20 subjects (10 males and 10 females) and 30 metaphases per individual were analyzed cytogenetically. Were carried out by impregnation techniques silver (Ag-NOR). The observed modal diploid number was 2n = 60 (26m +26 sm +8 st), with the variable occurrence of 1 or 2 Bs chromosomes in males and a B chromosome in females, both acrocentric. Regarding the variation in the frequency of chromosome Bs, the occurrence of two B chromosomes is directly linked to males, because there were no female sampled with the occurrence of two chromosomes Bs The low frequency of Bs in females suggests that this event can be sporadic this sex, different from males in which this appears to be set supernumerary chromosome showing a higher frequency of 2 Bs than the actual modal number of 2n = 60. Further studies will be performed to understand the dynamics of the B chromosome in the population
Resumo:
The present work aims to conduct a study of the economic feasibility of the implementation of variable frequency inverters in pump systems with variable flow rates. The concern with the reduction of energy expenditure in industries raised in 2001 due to the energy crisis that hit Brazil at that time, forcing industries to reduce their electric costs under penalty of fines if this were not done (MOREIRA, 2008). Frequency inverter is an electronic device that allow greater control in the operation of pumping systems and also a reduction in electrical consumption, being a viable solution to achieve a reduction in energy consumption. For the development of this work, approaching important topics in pumping systems was necessary in order to make a correct choice of hydraulic pumping and also other components responsible for the operation of the system , such as electric motors and frequency inverters. In the case study, a theoretical analysis of the behavior of electrical consumption in systems with variable flow rates was performed, comparing when the system is operated via frequency inverters and when the system is operated without such a device. As expected, the result of the implantation of the device was quite satisfactory, and the primary goal of reducing energy expenditure was achieved. Also important to highlight the environmental issue of this work, as all forms of energy production affects nature in some way, achieving a reduction in consumption also contributes indirectly in environmental conservation
Resumo:
Pós-graduação em Agronomia (Produção Vegetal) - FCAV
Resumo:
O objetivo deste trabalho é aplicar uma clássica ferramenta da Teoria de Singularidades, a saber, desdobramentos de funç˜oes reais, no estudo da estrutura local de alguns subconjuntos do espaço Euclidiano.
Resumo:
Micronuclei (MN) originate from chromosome fragments or whole chromosomes that lag behind at anaphase during cell division can occur due to excessive exposure to harmful agents, defects in mitosis and / or DNA repair process. The study evaluated the frequency of micronuclei in cytological samples after daily use of alcohol -based mouthwash mouth in smokers and non-smokers. We assessed 30 subjects, aged between 17-42 years and established as exclusion criteria: alcohol consumption; periodontal disease; systemic diseases that may interfere with the integrity of the oral mucosa; individuals with medical or pharmacological history that affect the performance of the study, family history of malignancies. For smokers the inclusion criterion was a minimum consumption of 20 cigarettes / day, and the contrast required for non-smokers. The sample was divided into 02 experimental groups: Group 1 Smokers and Group 2 Non-Smokers, both groups performed mouthwash (alcohol 21,6%) with Listerine® Defense of Teeth and Gums for 04 weeks cytological collection were performed on buccal mucosa and portion median border of the tongue, one for initial, week 0 control, and subsequent three weeks with continued use of mouthwash. The collected material was stained by specific staining Feulgen / Fast Green. The analysis of 3000 cells / individual was performed by light microscopy statistics used Kruskal- Wallis and Mann-Whitney tests for frequency MN. The frequency of micronuclei in buccal mucosa was 1.6 ± 1.75 and 1.46 ± 2.06 for the site language to Group 1 Smokers of showing a slight increase compared with Group 2 Non-smoking, which showed a variation of 1.2 ± 1.53 for the buccal mucosa site and 0.86 ± 1.41 for the site language. However, this difference was not statistically significant. The results suggest that alcohol-based mouthwash tested is not an inducer of genotoxic changes, thus not changing the frequency...
Resumo:
Pós-graduação em Matemática Universitária - IGCE
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Pós-graduação em Bases Gerais da Cirurgia - FMB