Background: This study aims to assess the effects of 8 weeks of plyometric jump training (PJT) conducted on sand or a rigid court surface on jump-related biomechanical variables and physical fitness in female indoor volleyball players. Methods: Seventeen participants were randomly divided into a sand surface group (SsG, n = 8) and rigid surface group (RsG, n = 9). Both groups completed equal indoor volleyball training routines. Participants were assessed pre and post the 8-week PJT for jump-related biomechanical variables (countermovement jump (CMJ) RSI; drop jump (DJ) reactive strength index (RSI); spike jump (SJ) height; CMJ height; CMJ rate of force development (RFD); CMJ velocity at take-off; DJ height and CMJ peak force), 20 m linear sprint time, t test for change-of-direction sprint (CODs) time, Wingate test peak power (PP), cardiorespiratory endurance, and leg-press one-repetition maximum (1RM). Results: A two-way mixed analysis of variance (group × time) revealed that there was a significant group × time interaction between DJ height (p = 0.035) and CMJ peak force (p = 0.032) in favour of RsG and SsG, respectively. A significant interaction was also observed for cardiorespiratory endurance (p = 0.01) and 1RM (p = 0.002), both favouring the SsG. No other group × time interaction was observed. Conclusions: The type of surface used during PJT induced specific adaptations in terms of jump-related biomechanical variables and physical fitness in female indoor volleyball players. Based on the individual needs of the athletes, practitioners may prescribe one type of surface preferentially over another to maximize the benefits derived from PJT.

Intense muscle contractile activity can result in reactive oxygen species production in humans. Thus, supplementation of antioxidant vitamins has been used to prevent oxidative stress, enhance performance, and improve muscle mass. In this sense, randomized controlled studies on the effect of vitamin C and E supplementation combined with strength training (ST) on skeletal muscle mass and strength have been conducted. As these studies have come to ambiguous findings, a better understanding of this topic has yet to emerge. The purpose of the present review is to discuss the current knowledge about the effect of vitamin C and E supplementation on muscle mass and strength gains induced by ST. Search for articles was conducted in the following databases: PubMed/Medline, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and Google Scholar. This work is in line with the recommendations of the PRISMA statement. Eligible studies were placebo-controlled trials with a minimum of four weeks of ST combined with vitamin C and E supplementation. The quality of each included study was evaluated using the Physiotherapy Evidence Database Scale (PEDro). 134 studies were found to be potentially eligible, but only seven were selected to be included in the qualitative synthesis. A meta-analysis of muscle strength was conducted with 3 studies. Findings from these studies indicate that vitamins C and E has no effect on muscle force production after chronic ST. Most of the evidence suggests that this kind of supplementation does not potentiate muscle growth and could possibly attenuate hypertrophy over time.

The ability of two fundamentally different photochemical procedures to inactivate model viruses in platelet suspensions was compared. Merocyanine 540 (MC 540) with visible light was used as an example of an oxygen-dependent chemical-directed at the viral membrane, and aminomethyl trimethyl psoralen (AMT) with ultraviolet A light (UVA) was used as an example of a nucleic acid-directed system. Antiviral conditions in petri dishes were identified and the effects of these procedures on platelet suspensions in plastic storage containers were studied. Concentrations of photochemicals in the 10 to 150 mumol range with 30 to 60 minutes of visible light (MC 540) or 1 to 2 minutes of UVA (AMT) readily inactivated 5 to 6 log10 of vesicular stomatitis virus (VSV) and other model viruses in platelet suspensions, provided the plasma concentration was reduced to about 15 percent by the use of a synthetic platelet storage medium. Extracellular pH, morphology scores, and aggregation response dropped markedly when platelets were treated with MC 540 and visible light. However, treatment with 136 mumol per L of AMT and 1 to 3 minutes of UVA could inactivate 5 log10 of VSV in platelet suspensions with retention of platelet characteristics for 4 days, particularly if oxygen levels were reduced during treatment. These studies demonstrate that AMT-UVA treatment meets the initial requirements for virus inactivation in platelet suspensions.

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Graduate students in chemistry, and in biological and biomedical fields must learn the fundamentals and practices of peptide and protein chemistry as early as possible. A project-oriented approach was conducted by first-year M.Sc and Ph.D students in biological sciences. A blind glass slide containing a cellular smear and an aqueous cellular extract were offered to the students. Qualitative and quantitative cell morphological parameters were analyzed by atomic force microscopy. The fractionation of the aqueous extract was conducted by reversed-phase chromatography followed by analysis of the isolated and partially purified proteins and peptides by mass spectrometry (MS). The proteins were treated by peptidases and the obtained peptide fragments were sequenced by de novo MS/MS, together with peptides already present in the extract. The most abundant protein fractions were identified as the alpha and beta chains of hemoglobin from an amphibian of the Leptodactylus genera. Two of the peptides sequenced by the students were synthesized by the solid-phase methodology, one of those being obtained by the splitand-pool library synthesis method. Thus, the students were able to learn some advanced principles and practices of protein chemistry and bionanotechnology in a 6-weeks project-oriented approach.

Exercise interventions have been recommended for people with non-specific low back pain. The literature is scarce regarding the effects of exercise on muscle strength, endurance, and electrical activity of lumbar extensor muscles. Electronic searches were carried out from May 2020 until August 2020 in the following databases: PUBMED, CENTRAL, EMBASE, PEDro, SPORTDiscus, Scielo, and LILACS. Only randomized controlled trials with passive and active control groups were included. The methodological quality of the included studies was performed using the Physiotherapy Evidence Database Scale. Eight studies, involving 508 participants, were included in metanalytical procedures. Exercise interventions demonstrated superior effects on muscle activity (Electromyography) when compared with active controls (p < 0.0001). Exercise interventions demonstrated superior effects on muscle endurance (Sorensen Test) when compared with passive (p = 0.0340) and active controls (p = 0.0276). Exercise interventions demonstrated superior effects on muscle strength (Machine) when compared with passive controls (p = 0.0092). Exercise interventions can improve muscle strength, endurance, and electrical activity in people with non-specific low back pain.

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Prezados (as) leitores (as), o presente livro trata-se de uma coletânea de pesquisas sobre os mais diversos e variados temas que fazem parte da área da saúde, desde suas indagações, até os problemas e soluções encontradas nesses. Ademais, espero que encontre frutíferas elucidações e indagações feitas. Para alguns autores o conhecimento é como um oceano a noite em que o leitor utilizando um barco e uma lanterna vê partes de um infinito mar que não tem fim, por meio de livros, mestres e pessoas que passam em seu caminho. Deste modo, portanto, esperamos que parte desse livro traga novas descobertas, tais quais como maravilhas em um oceano desconhecido para um viajante empolgado. SUMÁRIOAumento da prevalência de puberdade precoce: qual a influência de disruptores endócrinos?