5,215 research outputs found

    The impact of sport participation on bone mass and geometry in adolescent males

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    Exercise is an effective approach for developing bone mass and adolescence is a key period to optimize bone health. However, sports specific training may have different effects on bone outcomes. This study examined the differences on bone outcomes between osteogenic (football) and non-osteogenic (swimming and cycling) sports and a control group in adolescent males. Methods: One hundred twenty one males (13.1±0.1 years) were measured: 41 swimmers, 37 footballers, 29 cyclists and 14 controls. Dual energy X-ray absorptiometry measured bone mineral density (BMD) and content (BMC) at lumbar spine, right and left hip and total body. Hip structural analysis evaluated bone geometry at the femoral neck. Quantitative ultrasound evaluated bone stiffness at both feet. Results: Footballers had significantly higher BMD at total body less head (7-9%), total hip (12-2%) and legs (7-11%) compared to all groups and significantly higher BMD at the femoral neck than controls (14%). Cyclists had higher BMD at the trochanter (10%) and BMC at the arms (10%) compared to controls. Geometrical analysis showed that footballers had significantly higher cross-sectional area (8-19%) compared to all groups, cross-sectional moment of inertia (17 %) compared to controls and section modulus compared to cyclists (11%) and controls (21%). Footballers had significantly higher bone stiffness compared to all groups (10-20%) at the dominant foot and (12-13%) at the nondominant foot compared to swimmers and controls. Conclusions: Adolescent male footballers exhibited higher bone density, geometry and stiffness compared to swimmers, cyclists and controls. Although swimmers and cyclists had higher bone outcomes compared to controls, these differences were not significant.The research leading to these results has received funding from the European Union Seventh Framework Programme ([FP7/2007-2013] under grant agreement n°. PCIG13-GA-2013-618496

    FCNC Processes from D-brane Instantons

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    Low string scale models might be tested at the LHC directly by their Regge resonances. For such models it is important to investigate the constraints of Standard Model precision measurements on the string scale. It is shown that highly suppressed FCNC processes like K0- bar K^0 oscillations or leptonic decays of the D0-meson provide non-negligible lower bounds on both the perturbatively and surprisingly also non-perturbatively induced string theory couplings. We present both the D-brane instanton formalism to compute such amplitudes and discuss various possible scenarios and their constraints on the string scale for (softly broken) supersymmetric intersecting D-brane models.Comment: 28 pages, 13 figures, reference added, 1 typo corrected, style file adde

    Design and Characterization of Cyclosporine A-Loaded Nanofibers for Enhanced Drug Dissolution

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    Despite widespread use as an immunosuppressant, the therapeutic efficacy of the undecapeptide cyclosporine A (CyA) is compromised when given by the oral route because of the innate hydrophobicity of the drug molecule, potentially leading to poor aqueous solubility and bioavailability. The aim of this study was to develop and characterize nanofibers based on the water-miscible polymer polyvinylpyrrolidone (PVP), incorporating CyA preloaded into polymeric surfactants so as to promote micelle formation on hydration; therefore, this approach represents the novel combination of three dissolution enhancement methodologies, namely solid dispersion technology, micellar systems, and nanofibers with enhanced surface area. The preparation of the nanofibers was performed in two steps. First, mixed micelles composed of the water-soluble vitamin E derivative d-α-tocopheryl poly(ethylene glycol) 1000 succinate and the amphiphilic triblock polymer Pluronic F127 (Poloxamer 407) were prepared. The micelles were characterized in terms of size, surface charge, drug loading, and encapsulation efficiency using transmission electron microscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, high-performance liquid chromatography, and scanning electron and atomic force microscopy analysis. Nanofibers composed of PVP and the drug-loaded surfactant system were then prepared via electrospinning, with accompanying thermal, spectroscopic, and surface topological analysis. Dissolution studies indicated an extremely rapid dissolution profile for the fibers compared to the drug alone, while wettability studies also indicated a marked decrease in contact angle compared to the drug alone. Overall, the new approach appears to offer a viable means for considerably improving the dissolution of the hydrophobic peptide CyA, with associated implications for improved oral bioavailability

    Paternal obesity is associated with IGF2 hypomethylation in newborns: results from a Newborn Epigenetics Study (NEST) cohort

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    Data from epidemiological and animal model studies suggest that nutrition during pregnancy may affect the health status of subsequent generations. These transgenerational effects are now being explained by disruptions at the level of the epigenetic machinery. Besides in vitro environmental exposures, the possible impact on the reprogramming of methylation profiles at imprinted genes at a much earlier time point, such as during spermatogenesis or oogenesis, has not previously been considered. In this study, our aim was to determine associations between preconceptional obesity and DNA methylation profiles in the offspring, particularly at the differentially methylated regions (DMRs) of the imprinted Insulin-like Growth Factor 2 (IGF2) gene
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