305 research outputs found
l-Leucine supplemented whey protein. Dose–response effect on heart mTOR activation of sedentary and trained rats
AbstractThe aim of the study was to investigate the effect of leucine supplementation combined with exercise and whey protein in cardiac mTOR anabolic pathway. Ninety-six weanling male Wistar rats were divided into eight groups and fed diets containing either casein or WP plus increasing levels (0, 3, 4.5 and 6% of diet) of l-leucine for 30days. A parallel set of eight groups was exercised for comparison. Serum aspartate amino transferase, alanine aminotransferase, creatine kinase, lactate dehydrogenase and branched chain amino acids were determined by standard methods, and mammalian target of rapamycin (mTOR) and p70S6K by the Western blot analysis. Chronic l-leucine supplementation was capable of increasing both mTOR and p70S6K phosphorylation in the heart in a dose-dependent fashion, independent of the type of dietary protein in both groups, sedentary and exercised, but the exercise potentialized the activation of the anabolic pathway. The content of protein in heart increase with l-leucine supplementation and the heart mass relativized by body mass did not change. In conclusion, the combination of l-leucine and milk proteins (casein or whey protein) has the potential to increase the mTOR pathway in the cardiac muscle without increasing the heart mass. The novelty of this study is to show the effectiveness of a blend of leucine and whey protein as a viable alternative to maximize the activation of the anabolic pathway of cardiac muscle and that the exercise can improve this process
A straightforward method to obtain the cohesive laws of bonded joints under mode I loading
Saturation of dephasing time in mesoscopic devices produced by a ferromagnetic state
We consider an exchange model of itinerant electrons in a Heisenberg
ferromagnet and we assume that the ferromagnet is in a fully polarized state.
Using the Holstein-Primakoff transformation we are able to obtain a
boson-fermion Hamiltonian that is well-known in the interaction between light
and matter. This model describes the spontaneous emission in two-level atoms
that is the proper decoherence mechanism when the number of modes of the
radiation field is taken increasingly large, the vacuum acting as a reservoir.
In the same way one can see that the interaction between the bosonic modes of
spin waves and an itinerant electron produces decoherence by spin flipping with
a rate proportional to the size of the system. In this way we are able to show
that the experiments on quantum dots, described in D. K. Ferry et al. [Phys.
Rev. Lett. {\bf 82}, 4687 (1999)], and nanowires, described in D. Natelson et
al. [Phys. Rev. Lett. {\bf 86}, 1821 (2001)], can be understood as the
interaction of itinerant electrons and an electron gas in a fully polarized
state.Comment: 10 pages, no figure. Changed title. Revised version accepted for
publication in Physical Review
Characterization and basic guidelines for the quality control of chitosan for drug delivery in pharmaceutical applications
Chitosan is increasingly used as an alternative to synthetic polymers due to its water solubility, biodegradability, and biological activity. In this work, chitosan samples from three suppliers were evaluated and characterized by physicochemical methods in an attempt to analyze pharmaceutical applications. The degree of deacetylation (DD) was determined by 1H NMR, IR spectra, potentiometric titration, and UV spectrophotometry. The analysis was supplemented by the techniques of DSC, TG, loss on drying, pH of the suspension, heavy metals, sulphated ash, and triple detector size exclusion chromatography (TriSEC). The use of UV, IR, and 1H NMR techniques to determine the degree of deacetylation, limit testing for heavy metals and sulphated ash to analyze inorganic waste, and TriSEC to analyze molecular weights and molecular distribution are recommended as basic requirements for pharmaceutical applications.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Flutuação populacional de Rhynchophorus palmarum (L.) (Coleoptera: Curculionidae) em palmeiras oleíferas no Amazonas
Plants and their active constituents from South, Central, and North America with hypoglycemic activity
Epidemiological, clinical and immunohistochemical aspects of canine lymphoma in the region of Porto Alegre, Brazil
Partonic flow and -meson production in Au+Au collisions at = 200 GeV
We present first measurements of the -meson elliptic flow
() and high statistics distributions for different
centralities from = 200 GeV Au+Au collisions at RHIC. In
minimum bias collisions the of the meson is consistent with the
trend observed for mesons. The ratio of the yields of the to those of
the as a function of transverse momentum is consistent with a model
based on the recombination of thermal quarks up to GeV/,
but disagrees at higher momenta. The nuclear modification factor () of
follows the trend observed in the mesons rather than in
baryons, supporting baryon-meson scaling. Since -mesons are
made via coalescence of seemingly thermalized quarks in central Au+Au
collisions, the observations imply hot and dense matter with partonic
collectivity has been formed at RHIC.Comment: 6 pages, 4 figures, submit to PR
Measurement of Transverse Single-Spin Asymmetries for Di-Jet Production in Proton-Proton Collisions at GeV
We report the first measurement of the opening angle distribution between
pairs of jets produced in high-energy collisions of transversely polarized
protons. The measurement probes (Sivers) correlations between the transverse
spin orientation of a proton and the transverse momentum directions of its
partons. With both beams polarized, the wide pseudorapidity () coverage for jets permits separation of Sivers functions for the valence
and sea regions. The resulting asymmetries are all consistent with zero and
considerably smaller than Sivers effects observed in semi-inclusive deep
inelastic scattering (SIDIS). We discuss theoretical attempts to reconcile the
new results with the sizable transverse spin effects seen in SIDIS and forward
hadron production in pp collisions.Comment: 6 pages total, 1 Latex file, 3 PS files with figure
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
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