30 research outputs found

    Relationship between biomarkers of muscle damage and redox status in response to a weightlifting training session: effect of time-of-day

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    The aims of the present study were to: (1) investigate the effect of a weightlifting training session and time-of-day (TOD) upon biological parameters (i.e., oral temperature, hematological, C-reactive protein (CRP), and oxidative stress) and (2) assess their possible link with muscle damage responses. Nine weightlifters (21 ± 0.5 years) performed, in a randomized order, three Olympic-Weightlifting sessions (i.e., at 08:00, 14:00, and 18:00). Blood samples were collected at rest, 3 min and 48 h after each training session. Between pre- and post-training session, ANOVA showed significant increases in oxidative stress markers at the three TODs (p < 0.01) and significant increases for creatine kinase (CK) and lactate dehydrogenase (LDH) only at 08:00 and 18:00 (p < 0.05). At rest, the results showed a significant diurnal variation for the majority of the selected parameters except for malondialdehyde (MDA), total bilirubin, and CRP with higher values observed at 18:00 (p < 0.05). After the training session, given the higher rate of increase during the morning session, these diurnal variations persisted for temperature and WBC (p < 0.01) and were suppressed for CK, LDH, uric acid (UA), catalase, and glutathione peroxidase. The main significant correlations (p < 0.001) were observed between: (1) CK and MDA (r = 0.6) and CK and UA (r = 0.66 and r = 0.82) during the morning and evening training sessions; (2) CK and CRP only during the morning session (r = 0.5); and (3) CRP and WBC during the three training sessions (r = 0.8). In conclusion, the present findings: (1) confirm that the muscle damage responses could be induced by a high level of oxidative stress and (2) suggest to avoid scheduling training sessions in the morning given the higher muscle damage, inflammatory, and oxidative responses at this TOD

    Application of an experimental design to study AISI 4340 and 300M steels electropolishing in a concentrated perchloric/acetic acid solution

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    The objective of this study was to assess AISI 4340 and 300 M steels electropolishing performance in aconcentrated perchloric/acetic acid electrolyte. The statistical analysis on a two-level fractional design(FFD)24-1was proposed to define an adequate tool to describe the dissolved thickness and thefinalsurface via arithmetic roughness Ra. A compromise zone was defined for each steel by considering allthe requirements for both responses of each steel: dissolved thickness between 15–17μm andarithmetic roughness criteria less than 0.06μ

    Tumeur neuro-ectodermique primitive du rein avec insuffisance rénale

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    Introduction : Les Tumeurs neuroectodermiques périphériques (PNET) ou le sarcome d'Ewing est un cancer qui se développe habituellement dans les os et la localisation extrasquelettique est rare. Les PNET de localisation rénale sont rares et se caractérisent par une évolution clinique agressive et un mauvais pronostic. Seuls quelques cas de PNET rénaux avec insuffisance rénale ont été rapportés dans la littérature à ce jour.  Cas clinique : Nous présentons un cas de PNET rénal chez un homme de 48 ans sans antécédents médicaux, qui présentait une douleur au flanc droit, imitant des coliques nephretiques. Une échographie abdominale a montré une masse rénale droite.  La tomodensitométrie a montré une masse du rein droit de 23x9 cm associée à une carcinose péritonéale, la tumeur été localement avancé avec invasion vasculaire et des structures adjacentes. L'analyse histologique a trouvé de petites cellules rondes monomorphes qui forment des rosettes. à l’immunohistochimie, les cellules tumorales sont fortement positifs pour le CD99 et la vimentine confirmant le diagnostic de PNET. Le patient a développé une insuffisance rénale au début de l'évolution de la maladie qui nous a empêchés de réaliser le bilan d’extension de la maladie et de prescrire une chimiothérapie. Le patient est décédé de sa maladie trois mois plus tard.Discussion : Les Tumeur neuroectodermique périphérique (PNET) de localisation rénale surviennent généralement pendant l'enfance, l'adolescence ou chez le jeune adulte ce qui n’est pas le cas de notre patient (48 ans). L’insuffisance rénale en association avec les PNET rénaux a été rapportée précédemment dans seulement quelques cas pédiatriques, mais pas dans la population adulte. cette insuffisance rénale peut être expliquer par: d'une part le thrombus direct qui envahit la veine rénale (20 à 30% des cas en pédiatrie), d'autre part l'étendue de la tumeur elle-même dans le rein et enfin la compression  par les adénopathies régionales. La présence d'une fonction rénale altérée complique encore la gestion de ces patients à risque élevé avant le traitement et également après le début de la chimiothérapie. Et ceci est un obstacle à l'utilisation d’une chimiothérapie potentiellement néphrotoxiques et de produit de contraste pour l'imagerie. Devrions-nous utiliser l'échographie, la tomodensitométrie sans produit de contraste ou l’imagerie par résonance magnétique pour la stadification et le suivi ? D'autres recherches peuvent répondre à ces questions.Conclusion : Les PNET de localisation rénale doivent être envisagées dans les tumeurs rénales de tous âges, mais plus particulièrement chez les enfants et les jeunes adultes. Cette tumeur a de nombreuses similitudes avec d'autres tumeurs rénales, il est important de diagnostiquer cette entité tôt avant l’apparition des complications et principalement l’insuffisance rénale

    Synthesis of primary amines by one-pot reductive amination of aldehydes.

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    We report here a novel, one-pot, two-step reductive amination of aldehydes for the atom-economical synthesis of primary amines. The amination step has been carried out with hydroxylammonium chloride and does not require the use of a base. In the subsequent reduction step, a metal zinc/hydrochloride acid system has been used. This method is applicable to both aliphatic and aromatic aldehydes. The operational simplicity, the short reaction times, and the mild reaction conditions add to the value of this method as a practical alternative to the reductive amination of aldehydes. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications1 to view the free supplemental file

    Crystal structure, NMR study, dc-conductivity and dielectric relaxation studies of a new compound [C 2

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    The crystal structure, the solid NMR spectroscopy and the complex impedance study have been carried out on [C2H10N2]CdCl2(SCN)2. Characterization by single crystal X-ray crystallography shows that the cadmium atoms have à 2N2S2Cl hexa-coordination sphere, exhibiting pseudo-octahedral geometry. The cadmium atoms are bridged by two thiocyanate ions generating 1-D polymeric-chains. These chains are themselves interconnected by means of N-H…Cl(NCS) hydrogen bonds originating from the organic cation [(NH3)2(CH2)2]2+. 111Cd isotropic chemical shifts span a range of 268ppm. The cadmium atom exhibits multiplets that result from 111Cd-14N spin-spin coupling. Examination of 111Cd and 13C MAS line shapes shows direct measurement of the indirect spin-spin coupling constant 2J(111Cd, 14N) = 105Hz and the dipolar coupling constant of 1381Hz . Impedance spectroscopy measurements of [C2H10N2]CdCl2(SCN)2 have been studied from 209Hz to 5 MHz over the temperature range 300-370 K. The Cole-Cole (Z” versus Z’) plots are fitted to two equivalent circuits models. The formalism of complex permittivity and impedance were employed to analyze the experimental data. The dc conductivity follows the Arrhenius relation with an activation energy Ea = 0.54 (3) eV

    Crystal structure, NMR study, dc-conductivity and dielectric relaxation studies of a new compound [C2H10N2]Cd(SCN)2Cl2

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    The crystal structure, the solid NMR spectroscopy and the complex impedance study have been carried out on [C2H10N2]CdCl2(SCN)2. Characterization by single crystal X-ray crystallography shows that the cadmium atoms have à 2N2S2Cl hexa-coordination sphere, exhibiting pseudo-octahedral geometry. The cadmium atoms are bridged by two thiocyanate ions generating 1-D polymeric-chains. These chains are themselves interconnected by means of N-H…Cl(NCS) hydrogen bonds originating from the organic cation [(NH3)2(CH2)2]2+. 111Cd isotropic chemical shifts span a range of 268ppm. The cadmium atom exhibits multiplets that result from 111Cd-14N spin-spin coupling. Examination of 111Cd and 13C MAS line shapes shows direct measurement of the indirect spin-spin coupling constant 2J(111Cd, 14N) = 105Hz and the dipolar coupling constant of 1381Hz . Impedance spectroscopy measurements of [C2H10N2]CdCl2(SCN)2 have been studied from 209Hz to 5 MHz over the temperature range 300-370 K. The Cole-Cole (Z” versus Z’) plots are fitted to two equivalent circuits models. The formalism of complex permittivity and impedance were employed to analyze the experimental data. The dc conductivity follows the Arrhenius relation with an activation energy Ea = 0.54 (3) eV

    Developing an advanced PWM-switch model including semiconductor device non-linearities

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    The accurate simulation of power electronic systems is possible when including accurate models of the semiconductor devices, but practically not affordable. Classical ideal averaged models of the system are not suitable either. Hence, averaged models including the non-linear effects of the power semiconductor devices appear quite efficient. The proposed non-ideal PWM-switch model is a useful method for modeling pulse width modulated converters operating in the continuous conduction mode. The main advantages of the proposed averaged model are the takes into account of the non-linear effects of power devices and the possibility to estimate the dissipated power in the different circuit devices. The proposed electrical model can be applied to bi-directional converters and allows the coupling with thermal model in the power electronic system. A simple technique to evaluate the different static and dynamic parameters of the devices, from manufacturers data sheets or experimentally, is presented

    Élaboration et caractérisations mécanique et morphologique de revêtements électrolytiques de chrome

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    L’emploi d’un revêtement s’avère souvent utile pour modifier les propriétés de surface d’un composant indépendamment de ses propriétés de volume. L’utilisation du courant pulsé permet d’améliorer sensiblement la qualité des revêtements métalliques. L'objectif de cette étude est de corréler les paramètres du procédé d’électrodéposition des revêtements de chrome et leurs propriétés structurales et fonctionnelles, en appliquant la méthode du plan d’expériences. Les films élaborés ont été observés par AFM et leurs caractéristiques mécaniques et morphologiques ont été étudiés
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