84 research outputs found

    Is anodal transcranial direct current stimulation a potential ergogenic resource for muscle strength and effort perception? A critical review

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    Nas últimas décadas, vários estudos estão investigando a dose-resposta ideal em termos de frequência, intensidade e volume de treinamento para alcançar o aumento da força muscular, tanto em atletas quanto em não atletas. A dose-resposta é fundamental para a prescrição do treinamento, uma vez que sua manipulação equivocada pode acarretar alto risco de desenvolvimento de lesões por esforços repetitivos, bem como pelo não desenvolvimento da força esperada. Em indivíduos com nível avançado de treinamento de força, é extremamente importante aumentar sua intensidade e volume de treinamento. Nesse sentido, com os avanços encontrados na área de treinamento de força e a necessidade de novas estratégias para otimizar ganhos de força, um novo método vem ganhando força na literatura, a estimulação transcraniana por corrente contínua (ETCC). Portanto, o objetivo deste estudo é analisar criticamente os efeitos do ETCC como potencial recurso ergogênico para a realização de força muscular e percepção de esforço, bem como se seu uso é ético ou não. Para tanto, foram pesquisadas as bases de dados Pubmed/Medline, ISI Web of Knowledge e Scielo, apenas em inglês, e com as palavras-chave: força muscular, resistência muscular, estimulação transcraniana por corrente contínua, ETCC. Nós comparamos o efeito do ETCC anódico (ETCC-a) com uma condição sham/controle nos resultados de ETCC para força muscular e percepção de esforço força muscular e percepção de esforço. Nenhum estudo menciona efeitos colaterais negativos da intervenção. Os dados mostram diferenças entre os estudos que investigam os estudos de avaliação da força muscular e resistência muscular, em termos do uso bem sucedido de ETCC. Estudos que investigaram a eficiência do ETCC na melhora da força muscular demonstraram efeitos positivos do ETCC-a em 66,7% dos parâmetros testados. Amaioria dos dados mostra consistentemente a influência do ETCC-a na força muscular, mas não no desempenho de resistênciaEn las últimas décadas, diversos estudios están investigando la dosis-respuesta ideal en cuanto a la frecuencia, intensidad y volumen de entrenamiento para alcanzar el aumento de fuerza muscular, sea en atletas y no atletas. La dosis-respuesta es fundamental para la prescripción de entrenamiento, pues su manipulación equivocada puede llevar a un alto de riesgo de desarrollo de lesiones por esfuerzo repetitivo, así como para el no desarrollo de la fuerza esperada. En sujetos con nivel avanzado de entrenamiento de fuerza es extremadamente importante aumentar su intensidad y volumen de entrenamiento. En este sentido, con los avances encontrados en el área de entrenamiento de fuerza y la necesidad de nuevas estrategias para optimizar las ganancias de fuerza, un nuevo método está ganando fuerza en la literatura, la estimulación transcraneal por corriente continua (ETCC). Por lo tanto, el objetivo del presente estudio es analizar de forma crítica los efectos de la ETCC como potencial recurso ergogénico al desempeño de fuerza muscular y percepción de esfuerzo, así como si su uso es ético o no. Por lo tanto, se realizó una búsqueda en las bases de datos Pubmed/Medline, ISI Web of Knowledge y Scielo, solamente en inglés y con las palabras clave: fuerza muscular, resistencia muscular, estimulación transcraneal de corriente continua, ETCC. Comparamos el efecto de la ETCC anódica (ETCC-a) a una condición sham/control sobre los resultados de la fuerza muscular y percepción de esfuerzo. Ningún estudio menciona efectos secundarios negativos de la intervención. Los datos muestran diferencias entre los estudios que investigan la fuerza muscular y los estudios de evaluación de resistencia muscular, en lo que se refiere al uso exitoso de la ETCC. Los estudios que investigan la eficiencia de la ETCC en la mejora de la fuerza muscular demuestran efectos positivos de la ETCC-a en el 66,7% de los parámetros probados. La mayoría de los datos muestran consistentemente influencia de la ETCC-a en la fuerza muscular, pero no en el rendimiento de resistencia.In the last decades, several studies are investigating the optimal dose-response in terms of frequency, intensity and volume of training to achieve increased muscle strength in both athletes and non-athletes. Dose-response is critical to the prescription of training, since its mismanagement may pose a high risk of developing repetitive strain injuries as well as failure to develop the expected strength. In individuals with advanced level of strength training, it is extremely important to increase their intensity and training volume. In this sense, with the advances in the area of strength training and the need for new strategies to optimize force gains, a new method is gaining strength in the literature, the transcranial direct current stimulation (tDCS). Therefore, the purpose of this study is to critically analyze the effects of tDCS as a potential ergogenic resource for achieving muscle strength and perceived exertion, as well as whether its use is ethical or not. To do so, we searched the databases Pubmed/Medline, ISI Web of Knowledge and Scielo, in English only, and with the keywords: muscle strength, muscular endurance, transcranial direct current stimulation, tDCS. We compared the effect of anodic tDCS (a-tDCS) with a sham/control condition on muscle strength and perceived exertion results. No study mentions the negative side effects of the intervention. The data show differences between studies investigating studies of muscle strength and muscle endurance in terms of the successful use of tDCS. Studies that investigated tDCS efficiency in improving muscle strength demonstrated positive effects of a-tDCS on 66.7% of the parameters tested. Most data consistently show the influence of a-tDCS on muscle strength, but not on resistance performance.info:eu-repo/semantics/publishedVersio

    Energy Conditions in f(G)f(G) Modified Gravity with Non-minimal Coupling to Matter

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    In this paper we study a model of modified gravity with non-minimal coupling between a general function of the Gauss-Bonnet invariant, f(G)f(G), and matter Lagrangian from the point of view of the energy conditions. Such model has been introduced in Ref. [21] for description of early inflation and late-time cosmic acceleration. We present the suitable energy conditions for the above mentioned model and then, we use the estimated values of the Hubble, deceleration and jerk parameters to apply the obtained energy conditions to the specific class of modified Gauss-Bonnet models.Comment: 12 pages, no figur, Accepted for publication in Astrophysics and Space Scienc

    The Presence of Flavonoids in Some Products and Fruits of the Genus Eugenia: An Integrative Review

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    ReviewThe Myrtaceae family, one of the most prominent botanical families, is represented in Brazil with different fruit species, rich in bioactive compounds and gastronomically appreciated. This study aimed to carry out an integrative review on the genus Eugenia, highlighting the pitangueira (E. uniflora L.), cagaiteira (E. dysenterica), grumixameira (E. brasiliensis), pereira (E. klotzschiana O. Berg), and uvaieira (E. pyriformis Cambess) and which flavonoids are present in these fruits. Articles published between 2016 and 2021 were selected from the following databases: Google Scholar, Periódicos CAPES, Scielo, and Science Direct. According to each database, the descriptors used as a search strategy addressed the popular and scientific names of the five selected species, associated or not with the term “flavonoid,” according to each database. The results showed that quercetin was the main flavonoid identified in the fruits, and the principal extraction method used was HPLC. Other interesting compounds, such as catechin, epicatechin, rutin, myricetin, and kaempferol, were also found. However, the amount and type of flavonoids detected varied according to the applied methodology. Hence, these studies highlight the importance of species of the genus Eugenia, which promotes beneficial health effects and possible applicability to the food and pharmaceutical industryinfo:eu-repo/semantics/publishedVersio

    Magnetic states of granular layered CoFe-Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e

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    The granular layered magnetic system Co80Fe20(t)/Al2 O3 (3 nm), where the Co80Fe20 layers of nominal thickness t form separate, almost spherical magnetic granules of typical diameter 2-3 nm between the Al2O3 spacers, was studied. We discuss measurements of the dc and ac magnetic susceptibility χ for 1 n

    Combined constraints on modified Chaplygin gas model from cosmological observed data: Markov Chain Monte Carlo approach

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    We use the Markov Chain Monte Carlo method to investigate a global constraints on the modified Chaplygin gas (MCG) model as the unification of dark matter and dark energy from the latest observational data: the Union2 dataset of type supernovae Ia (SNIa), the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. In a flat universe, the constraint results for MCG model are, Ωbh2=0.022630.00162+0.00184\Omega_{b}h^{2}=0.02263^{+0.00184}_{-0.00162} (1σ1\sigma) 0.00195+0.00213^{+0.00213}_{-0.00195} (2σ)(2\sigma), Bs=0.77880.0723+0.0736B_{s}=0.7788^{+0.0736}_{-0.0723} (1σ1\sigma) 0.0904+0.0918^{+0.0918}_{-0.0904} (2σ)(2\sigma), α=0.10790.2539+0.3397\alpha=0.1079^{+0.3397}_{-0.2539} (1σ1\sigma) 0.2911+0.4678^{+0.4678}_{-0.2911} (2σ)(2\sigma), B=0.001890.00756+0.00583B=0.00189^{+0.00583}_{-0.00756} (1σ1\sigma) 0.00915+0.00660^{+0.00660}_{-0.00915} (2σ)(2\sigma), and H0=70.7113.142+4.188H_{0}=70.711^{+4.188}_{-3.142} (1σ1\sigma) 4.149+5.281^{+5.281}_{-4.149} (2σ)(2\sigma).Comment: 12 pages, 1figur

    Genetic signatures of parental contribution in black and white populations in Brazil

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    Two hundred and three individuals classified as white were tested for 11 single nucleotide polymorphisms plus two insertion/deletions in their Y-chromosomes. A subset of these individuals (n = 172) was also screened for sequences in the first hypervariable segment of their mitochondrial DNA (mtDNA). In addition, complementary studies were done for 11 of the 13 markers indicated above in 54 of 107 black subjects previously investigated in this southern Brazilian population. The prevalence of Y-chromosome haplogroups among whites was similar to that found in the Azores (Portugal) or Spain, but not to that of other European countries. About half of the European or African mtDNA haplogroups of these individuals were related to their places of origin, but not their Amerindian counterparts. Persons classified in these two categories of skin color and related morphological traits showed distinct genomic ancestries through the country. These findings emphasize the need to consider in Brazil, despite some general trends, a notable heterogeneity in the pattern of admixture dynamics within and between populations/groups

    SND@LHC: The Scattering and Neutrino Detector at the LHC

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    SND@LHC is a compact and stand-alone experiment designed to perform measurements with neutrinos produced at the LHC in the pseudo-rapidity region of 7.2<η<8.4{7.2 < \eta < 8.4}. The experiment is located 480 m downstream of the ATLAS interaction point, in the TI18 tunnel. The detector is composed of a hybrid system based on an 830 kg target made of tungsten plates, interleaved with emulsion and electronic trackers, also acting as an electromagnetic calorimeter, and followed by a hadronic calorimeter and a muon identification system. The detector is able to distinguish interactions of all three neutrino flavours, which allows probing the physics of heavy flavour production at the LHC in the very forward region. This region is of particular interest for future circular colliders and for very high energy astrophysical neutrino experiments. The detector is also able to search for the scattering of Feebly Interacting Particles. In its first phase, the detector will operate throughout LHC Run 3 and collect a total of 250 fb1\text{fb}^{-1}
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