Search results for "c12"

Green Synthesis, Molecular Characterization and Associative Behavior of Some Gemini Surfactants without a Spacer Group.

2013

A series of new gemini surfactants without a spacer group, disodium 2,3-dialkyl-1,2,3,4-butanetetracarboxylates, were synthesized in a green chemistry context minimizing the use of organic solvents and applying microwaves (MW) when activation energy was required. Once the desired architecture was confirmed by means of the nuclear magnetic resonance technique (1H-NMR, 1H-1H COSY) for all the studied surfactants, the critical micellization concentration was determined by conductance measurements. The diffusion coefficient of micelles formed by the four compounds was characterized using pulsed field gradient (PFG)-NMR. Diffusion coefficients were found to be dependent on the concentration and …

Hsp60 expression in skeletal muscle increase after endurance training

2014

Auto-conceito na pré-adolescência: Uma breve versão da escala AF5

2014

The purpose of this study was to analyze the psychometric properties of a brief version of the AF5 questionnaire (García & Musitu, 2001) using exploratory and confirmatory techniques on a preadolescent population in the Valencian community (Spain). The sample was made up of 541 participants between 10 and 12 years old, 55.1% (298) boys and 44.9% (243) girls. After observing the results of different reliability and validity analyses (exploratory factor analysis (EFA) and confirmatory factor analysis (CFA)), it was found that the reduced scale consisting of 20 items showed a similar reliability and validity to the original scale. The factorial structure also fits that of the original model es…

THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY

2013

The aim of this study was to simulate the activity pattern of rink hockey by designing a specific skate test (ST) to study the energy expenditure and metabolic responses to this intermittent high-intensity exercise and extrapolate the results from the test to competition. Six rink hockey players performed, in three phases, the 20-metre multi-stage shuttle roller skate test, a tournament match and the ST. Heart rate was monitored in all three phases. Blood lactate, oxygen consumption, ventilation and respiratory exchange ratio were also recorded during the ST. Peak HR was 190.7±7.2 beats · min(-1). There were no differences in peak HR between the three tests. Mean HR was similar between the …

Effects of the exercise in the cerebral blood flow and metabolism: A review

2015

In recent years it has been shown that cerebral blood flow is affected by intense exercise, what may even lead to a reduction in the cognitive capacity. This statement is contrary to the traditional belief that cerebral blood flood remains constant and unaltered even when exercise is performed. During physical exercise of moderate intensity, cerebral blood flow increases in the cerebral areas responsible for movement. Moreover, recent studies have observed that cerebral blood flow decreases during high-intensity exercise as a consequence of a local hyperventilation and vasoconstriction of the areas with lower cerebral activity. Traditionally, the glucose has been considered as the main and …

Carbon Nanotubes Dispersion Assessment in Nanocomposites by Means of a Pulsed Thermographic Approach

2020

The extensive production of polymer composites reinforced by carbon nanotube is limited by the absence of non-destructive evaluation (NDE) methods capable of assessing product quality to guarantee compliance with specifications. It is well known that the level of dispersion of carbon nanotubes (CNTs) in the polymer matrix is the parameter that, much more than others, can influence their enhancement capabilities. Here an active Infrared Thermography Non Destructive Testing(IR-NDT) inspection, joined with pulsed phase thermography (PPT), were applied for the first time to epoxy-CNT composites to evaluate the level of dispersion of the nanoparticles. The PPT approach was tested on three groups…

A standard calculation methodology for human doubly labeled water studies.

2021

Summary The doubly labeled water (DLW) method measures total energy expenditure (TEE) in free-living subjects. Several equations are used to convert isotopic data into TEE. Using the International Atomic Energy Agency (IAEA) DLW database (5,756 measurements of adults and children), we show considerable variability is introduced by different equations. The estimated rCO2 is sensitive to the dilution space ratio (DSR) of the two isotopes. Based on performance in validation studies, we propose a new equation based on a new estimate of the mean DSR. The DSR is lower at low body masses (<10 kg). Using data for 1,021 babies and infants, we show that the DSR varies non-linearly with body mass betw…

β1D Integrin Inhibits Cell Cycle Progression in Normal Myoblasts and Fibroblasts

1998

Integrins are alphabeta heterodimeric transmembrane receptors involved in the regulation of cell growth and differentiation. The beta1 integrin subunit is widely expressed in vivo and is represented by four alternatively spliced cytoplasmic domain isoforms. beta1D is a muscle-specific variant of beta1 integrin and a predominant beta1 isoform in striated muscles. In the present study we showed that expression of the exogenous beta1D integrin in C2C12 myoblasts and NIH 3T3 or REF 52 fibroblasts inhibited cell proliferation. Unlike the case of the common beta1A isoform, adhesion of beta1D-transfected C2C12 myoblasts specifically via the expressed integrin did not activate mitogen-activated pro…

Representation of physical activity domains and sedentary behaviors across categories of gender and disability in children’s TV cartoons

2018

Television (TV) cartoons could reflect and shape social values about children’s health-related behaviors. The main aim of this study is to analyze the portrayal of physical activity (PA) domains in the most popular Spanish children’s television (TV) cartoons. It is performed a content analysis of each scene following a coding scheme. The sample selected included the five most popular children’s TV cartoons for the 2013-2014 period in Spain. Our results show a large gap between the modest representation of different PA domains compared to the overwhelming depiction of sedentary behaviors. We do not find evidence of males and females participating equally in a variety of PA domains, and we fa…

Lenses on very curved zones of a singular foliation of C2

2018

Abstract We renormalize, using suitable lenses, small domains of a singular holomorphic foliation of C 2 where the curvature is concentrated. At a proper scale, the leaves are almost translates of a graph that we will call profile. When the leaves of the foliations are levels f = λ , where f is a polynomial in 2 variables, this graph is polynomial. Finally we will indicate how our methods may be adapted to study levels of polynomials and 1-forms in C 3 .