1,205 research outputs found
Acute effect of caffeine supplementation on performance of muscular strength and cardiovascular changes during resistance training
The purpose of the present study was to evaluate the acute effect of caffeine on the muscular strength performance in addition to the possible hemodynamic changes during a strength training session. Thirteen strength training experienced male subjects were submitted to a protocol of three sets of 10RM for bench press (BP), pull press (PP), leg extension (LE) and leg curl (LC), according to three conditions: no supplementation (C); 250 mg of caffeine supplementation (S); placebo (P). All subjects were submitted to an anthropometric evaluation, followed by a 10RM familiarization test. Hemodynamic measurements – heart rate (HR) and blood pressure (BP) – were carried out before, during and after each session. Holding 48 hours time intervals, participants were submitted to three randomly presented 10RM tests according to C, S and P conditions. For conditions S and C, significant differences were found in BP and LE. No significant differences in HR and BP were found. Results seem to suggest an ergogenic effect of caffeine on submaximal muscle strength during a session of strength training
Práticas de educação ambiental em aulas de química em uma visão socioambiental: perspectivas e desafios
Neste artigo, são apresentados resultados obtidos em quatro estudos de casos sobre a
introdução de educação ambiental em uma visão socioambiental em aulas de Química.
A discussão dos resultados levanta reflexões sobre perspectivas e desafios para a
educação ambiental no ensino de Química. São demonstradas sugestões de atividades
possíveis de serem desenvolvidas em aulas de Químicas. Várias fontes de dados
foram usadas, como entrevistas, questionários, produção de textos pelos estudantes,
pré e pós-testes e observações registradas em diário de campo. Os estudos de caso
foram conduzidos por mestrandos que deveriam propor ações práticas para
professores em sua dissertação de mestrado. Os dados demonstram que a educação
ambiental é um desafio que requer diferentes estratégias de ensino e ações
coordenadas com a escola para que possa ser trabalhada em uma visão
socioambiental; o que depende de condições na escola para engajar os professores
em seus projetos
Artificial Motor Control For Electrically Stimulated Upper Limbs Of Plegic Or Paretic People
Functional Electrical Stimulation (FES) is a technique used in the restoration and generation of movements performed by subjects with neuromuscular disorders such as spinal cord injury (SCI). The purpose of this article is to outline the state of the art and perspectives of the use of FES in artificial motor control of the upper limbs in paretic or plegic people. Methods: The databases used in papers selection were Google Scholar and Capes’ Portals as well as proceedings of the Annual Conference of the International Functional Electrical Stimulation Society (IFESS). Results: Approximately 85% of the reviewed studies showed FES profile with pulse duration ranging from 1 to 300 μs and modulating (burst) frequency between 10 and 40 Hz. Regarding the type of electrodes, 88% of the studies employed transcutaneous electrodes. Conclusion: We concluded that FES with closed-loop feedback and feedforward are the most used and most viable systems for upper limbs motor control, because they perform self-corrections slowing neuromuscular adaptation, allowing different planes and more range of movement and sensory-motor integration. One of the difficulties found in neuroprosthesis systems are electrical wires attached to the user, becoming uninteresting in relation to aesthetics and break. The future perspectives lead to a trend to miniaturization of the stimulation equipment and the availability of wireless networks, which allow the attachment of modules to other components without physical contact, and will become more attractive for daily use. © 2016, Sociedade Brasileira de Engenharia Biomedica. All rights reserved.32219921
Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora
The brown algae Padina gymnospora contain different fucans. Powdered algae were submitted to proteolysis with the proteolytic enzyme maxataze. The first extract of the algae was constituted of polysaccharides contaminated with lipids, phenols, etc. Fractionation of the fucans with increasing concentrations of acetone produced fractions with different proportions of fucose, xylose, uronic acid, galactose, and sulfate. One of the fractions, precipitated with 50% acetone (v/v), contained an 18-kDa heterofucan (PF1), which was further purified by gel-permeation chromatography on Sephadex G-75 using 0.2 M acetic acid as eluent and characterized by agarose gel electrophoresis in 0.05 M 1,3 diaminopropane/acetate buffer at pH 9.0, methylation and nuclear magnetic resonance spectroscopy. Structural analysis indicates that this fucan has a central core consisting mainly of 3-ß-D-glucuronic acid 1-> or 4-ß-D-glucuronic acid 1 ->, substituted at C-2 with alpha-L-fucose or ß-D-xylose. Sulfate groups were only detected at C-3 of 4-alpha-L-fucose 1-> units. The anticoagulant activity of the PF1 (only 2.5-fold lesser than low molecular weight heparin) estimated by activated partial thromboplastin time was completely abolished upon desulfation by solvolysis in dimethyl sulfoxide, indicating that 3-O-sulfation at C-3 of 4-alpha-L-fucose 1-> units is responsible for the anticoagulant activity of the polymer.Universidade Federal do Rio Grande do Norte Departamento de Bioquímica Laboratório de GlicobiologiaUniversidade Federal do Rio Grande do Norte Departamento de Bioquímica Laboratório de Biotecnologia de Polímeros NaturaisUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de BioquímicaUNIFESP, EPM, Depto. de BioquímicaSciEL
Ciprofloxacin intercalated in fluorohectorite clay:identical pure drug activity and toxicity with higher adsorption and controlled release rate
Topografía Infraclavicular De Los Fascículos Del Plexo Braquial En Diferentes Posiciones Del Miembro Superior
Brachial plexus neuropathies are common complaints among patients seen at orthopedic clinics. The causes range from traumatic to occupational factors and symptoms include paresthesia, paresis, and functional disability of the upper limb. Treatment can be surgical or conservative, but detailed knowledge of the brachial plexus is required in both cases to avoid iatrogenic injuries and to facilitate anesthetic block, preventing possible vascular punctures. Therefore, the objective of this study was to evaluate the topography of the infraclavicular brachial plexus fascicles in different upper limb positions adopted during some clinical procedures. A formalin-preserved, adult, male cadaver was used. The infraclavicular and axillary regions were dissected and the distance of the brachial plexus fascicles from adjacent bone structures was measured. No anatomical variation in the formation of the brachial plexus was observed. The metric relationships between the brachial plexus and adjacent bone prominences differed depending on the degree of shoulder abduction. Detailed knowledge of the infraclavicular topography of neurovascular structures helps with the diagnosis and especially with the choice of conservative or surgical treatment of brachial plexus neuropathies. © 2016, Universidad de la Frontera. All rights reserved.3431063106
Molecular dynamics simulations of vibrated granular gases
We present molecular dynamics simulations of mono- or bidisperse inelastic
granular gases driven by vibrating walls, in two dimensions (without gravity).
Because of the energy injection at the boundaries, a situation often met
experimentally, density and temperature fields display heterogeneous profiles
in the direction perpendicular to the walls. A general equation of state for an
arbitrary mixture of fluidized inelastic hard spheres is derived and
successfully tested against numerical data. Single-particle velocity
distribution functions with non-Gaussian features are also obtained, and the
influence of various parameters (inelasticity coefficients, density...)
analyzed. The validity of a recently proposed Random Restitution Coefficient
model is assessed through the study of projected collisions onto the direction
perpendicular to that of energy injection. For the binary mixture, the
non-equipartition of translational kinetic energy is studied and compared both
to experimental data and to the case of homogeneous energy injection
(``stochastic thermostat''). The rescaled velocity distribution functions are
found to be very similar for both species
Amazon forest dynamics under changing abiotic conditions in the early Miocene (Colombian Amazonia)
Amazon forest dynamics under changing abiotic conditions in the early Miocene (Colombian Amazonia)
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