993 resultados para co-doping
Resumo:
Stimulants are banned in-competition for all categories of sports by the World Anti-Doping Agency. A simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay employing electrospray ionisation in positive mode was developed in that work for the quantification in urine specimens of 4-methyl-2-hexaneamine, a primary amine exhibiting sympathomimetic properties. Following a simple pretreatment procedure, the analyte was separated using a gradient mobile phase on reverse phase C8 column. Selected reaction monitoring m/z 116.2-->57.3 was specific for detection of 4-methyl-2-hexaneamine and the assay exhibited a linear dynamic range of 50-700 ng/mL. The validated method has been successfully applied to analyze the target compound in food supplements as well as in urine specimens. The administered drug (40 mg) was detected at the level of 350 ng/mL in the urine up to 4 days.
Resumo:
The CD8 molecule is a glycoprotein expressed on a subset of mature T lymphocytes. It has been postulated to be a receptor for class I major histocompatibility complex molecules. In the mouse, CD8 is a heterodimer composed of Ly-2 and Ly-3 chains. We have isolated and analyzed cDNA and cosmid clones corresponding to the Ly-3 subunit. One of the isolated, cosmid clones was subsequently transfected, alone or in combination with the Ly-2 gene, into mouse Ltk- cells. Analysis of the Ly-2,3 molecules expressed at the surface of the double transfectants indicated that they are serologically and biochemically indistinguishable from their normal counterparts expressed on lymphoid cells. Ltk- cells transfected with the Ly-2 gene alone were shown to react with a subset of anti-CD8 monoclonal antibodies whereas Ly-3 transfectants did not stain with any of the anti-Ly-3 antibodies employed in this study. Since at least one of these antibodies (53-5.8) has been previously shown to recognize an epitope which is retained on the Ly-3 subunit after dissociation of the heterodimeric Ly-2,3 complex, these observations suggest that the expression of the Ly-2 polypeptide is required to permit the detectable cell surface expression of the antigenic determinants carried by the Ly-3 subunit.
Resumo:
The magnetization process of Co/Al oxide/Py trilayers and its evolution with the temperature have been analyzed. The particular behavior of the Co layers, including the shift of the hysteresis loops and a coercivity increase with the decrease of temperature, is related with the apparition of a CoO layer at the Co/Al-oxide interface.
Resumo:
Magnetization versus temperature in the temperature interval 2-200 K was measured for amorphous alloys of three different compositions: Fe 81.5B14.5Si4, Fe40Ni38 Mo4B18, and Co70Fe5Ni 2Mo3B5Si15. The measurements were performed by means of a SQUID (superconducting quantum interference device) magnetometer. The aim was to extract information about the different mechanisms contributing to thermal demagnetization. A powerful data analysis technique based on successive minimization procedures has demonstrated that Stoner excitations of the strong ferromagnetic type play a significant role in the Fe-Ni alloy studied. The Fe-rich and Co-rich alloys do not show a measurable contribution from single-particle excitations.
Resumo:
BACKGROUND: Letrozole radiosensitises breast cancer cells in vitro. In clinical settings, no data exist for the combination of letrozole and radiotherapy. We assessed concurrent and sequential radiotherapy and letrozole in the adjuvant setting. METHODS: This phase 2 randomised trial was undertaken in two centres in France and one in Switzerland between Jan 12, 2005, and Feb 21, 2007. 150 postmenopausal women with early-stage breast cancer were randomly assigned after conserving surgery to either concurrent radiotherapy and letrozole (n=75) or sequential radiotherapy and letrozole (n=75). Randomisation was open label with a minimisation technique, stratified by investigational centres, chemotherapy (yes vs no), radiation boost (yes vs no), and value of radiation-induced lymphocyte apoptosis (< or = 16% vs >16%). Whole breast was irradiated to a total dose of 50 Gy in 25 fractions over 5 weeks. In the case of supraclavicular and internal mammary node irradiation, the dose was 44-50 Gy. Letrozole was administered orally once daily at a dose of 2.5 mg for 5 years (beginning 3 weeks pre-radiotherapy in the concomitant group, and 3 weeks post-radiotherapy in the sequential group). The primary endpoint was the occurrence of acute (during and within 6 weeks of radiotherapy) and late (within 2 years) radiation-induced grade 2 or worse toxic effects of the skin. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00208273. FINDINGS: All patients were analysed apart from one in the concurrent group who withdrew consent before any treatment. During radiotherapy and within the first 12 weeks after radiotherapy, 31 patients in the concurrent group and 31 in the sequential group had any grade 2 or worse skin-related toxicity. The most common skin-related adverse event was dermatitis: four patients in the concurrent group and six in the sequential group had grade 3 acute skin dermatitis during radiotherapy. At a median follow-up of 26 months (range 3-40), two patients in each group had grade 2 or worse late effects (both radiation-induced subcutaneous fibrosis). INTERPRETATION: Letrozole can be safely delivered shortly after surgery and concomitantly with radiotherapy. Long-term follow-up is needed to investigate cardiac side-effects and cancer-specific outcomes. FUNDING: Novartis Oncology France.
Resumo:
Background: Urine is still the matrix of choice to fight against doping, because it can be collected non-invasively during anti-doping tests. Most of the World Anti-Doping Agency's accredited laboratories have more than 20 years experience in analyzing this biological fluid and the majority of the compounds listed in the 2010 Prohibited List - International Standard are eliminated through the urinary apparatus. Storing and transporting urine samples for doping analyses does not include a specific protocol to prevent microbial and thermal degradation. The use of a rapid and reliable screening method could enable determine reference intervals for urine specimens in doping control samples and evaluate notably the prevalence of microbial contamination known to be responsible for the degradation of chemical substances in urine.Methods: The Sysmex(R) UF-500i is a recent urine flow cytometer analyzer capable of quantifying BACT and other urinary particles such as RBC, WBC, EC, DEBRIS, CAST, PATH. CAST, YLC, SRC as well as measuring urine conductivity. To determine urine anti-doping reference intervals, 501 samples received in our laboratory over a period of two months were submitted to an immediate examination. All samples were collected and then transported at room temperature. Analysis of variance was performed to test the effects of factors such as gender, test type [in-competition, out-of-competition] and delivery time.Results: The data obtained showed that most of the urine samples were highly contaminated with bacteria. The other urine particles were also very different according to the factors.Conclusions: The Sysmex(R) UF-500i was capable of providing a snapshot of urine particles present in the samples at the time of the delivery to the laboratory. These particles, BACT in particular, gave a good idea of the possible microbial degradation which had and/or could have occurred in the sample. This information could be used as the first quality control set up in WADA (World Anti-Doping Agency) accredited laboratories to determine if steroid profiles, endogenous and prohibited substances have possibly been altered. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
Resumo:
The conditions for the analysis of selected doping substances by UHPSFC-MS/MS were optimized to ensure suitable peak shapes and maximized MS responses. A representative mixture of 31 acidic and basic doping agents was analyzed, in both ESI+ and ESI- modes. The best compromise for all compounds in terms of MS sensitivity and chromatographic performance was obtained when adding 2% water and 10mM ammonium formate in the CO2/MeOH mobile phase. Beside mobile phase, the nature of the make-up solvent added for interfacing UHPSFC with MS was also evaluated. Ethanol was found to be the best candidate as it was able to compensate for the negative effect of 2% water addition in ESI- mode and provided a suitable MS response for all doping agents. Sensitivity of the optimized UHPSFC-MS/MS method was finally assessed and compared to the results obtained in conventional UHPLC-MS/MS. Sensitivity was improved by 5-100-fold in UHPSFC-MS/MS vs. UHPLC-MS/MS for 56% of compounds, while only one compound (bumetanide) offered a significantly higher MS response (4-fold) under UHPLC-MS/MS conditions. In the second paper of this series, the optimal conditions for UHPSFC-MS/MS analysis will be employed to screen >100 doping agents in urine matrix and results will be compared to those obtained by conventional UHPLC-MS/MS.
Resumo:
Cette thèse se propose d?étudier les forces évolutives qui influencent la bal- ance entre coopération et conflit. Deux exemples sont analysés en détail, les sociétés d?insectes et l?association entre la fourmi Formica exsecta et son sym- bionte intracellulaire Wolbachia. Chacune de ces deux associations animales est caractérisée par la coexistence de coopération et de conflit. Les colonies d?insectes sociaux sont un exemple typique de coopération. Néanmoins, la détermination haplodiploïde du sexe crée des apparentements asymétriques entre les membres de la colonie qui se traduisent par des con- flits entre reines et ouvrières. Un des conflits les plus importants porte sur le sexe-ratio, l?investissement optimal en sexués males et femelles étant équilibré pour la reine, mais biaisé en faveur des femelles pour les ouvrières. Jusqu?ici, les modèles étudiant ce conflit se basaient uniquement sur les asymétries d?ap- parentement. La première partie de cette thèse (Chapitres 1 et 2) propose d?introduire dans des modèles de sexe-ratio les mécanismes proximaux utilisés par les deux parties pour influencer le sexe-ratio. Ces mécanismes, par leurs ef- fets négatifs sur la productivité de la colonie, peuvent entraîner des déviations importantes du sexe-ratio par rapport à la valeur prédite par des modèles clas- siques. De plus, la prise en compte de ces mécanismes nous permet d?étudier dans quelle mesure les parties opposées sont sélectionnées pour influencer le sexe-ratio. Enfin, les modèles génèrent des prédictions quant à l?issue du con- flit, c?est-à-dire un compromis où reines et ouvrières partagent le contrôle de l?investissement. La seconde partie du travail porte sur l?infection de la fourmi Formica ex- secta par le symbionte cytoplasmique Wolbachia. Ce symbionte, présent chez un grand nombre d?espèces d?Arthropodes, est transmis maternellement. Afin de se répandre dans la population d?hôtes, Wolbachia manipule la physiolo- gie reproductive de l?organisme qui l?abrite. Le Chapitre 3 décrit une étude consacrée aux variations du sexe-ratio produit dans des colonies de fourmis? en fonction de la présence ou de l?absence de Wolbachia. Le Chapitre 4 étudie l?association entre les lignées du symbionte et les haplotypes mitochondriaux des hôtes. L?étude de l?association entre les deux éléments maternellement transmis est d?un intérêt particulier chez Formica exsecta car le taux de migra- tion femelle très faible engendre une forte strucure génétique mitochondriale.
Resumo:
Environmentally harmful consequences of fossil fuel utilisation andthe landfilling of wastes have increased the interest among the energy producers to consider the use of alternative fuels like wood fuels and Refuse-Derived Fuels, RDFs. The fluidised bed technology that allows the flexible use of a variety of different fuels is commonly used at small- and medium-sized power plants ofmunicipalities and industry in Finland. Since there is only one mass-burn plantcurrently in operation in the country and no intention to build new ones, the co-firing of pre-processed wastes in fluidised bed boilers has become the most generally applied waste-to-energy concept in Finland. The recently validated EU Directive on Incineration of Wastes aims to mitigate environmentally harmful pollutants of waste incineration and co-incineration of wastes with conventional fuels. Apart from gaseous flue gas pollutants and dust, the emissions of toxic tracemetals are limited. The implementation of the Directive's restrictions in the Finnish legislation is assumed to limit the co-firing of waste fuels, due to the insufficient reduction of the regulated air pollutants in the existing flue gas cleaning devices. Trace metals emission formation and reduction in the ESP, the condensing wet scrubber, the fabric filter, and the humidification reactor were studied, experimentally, in full- and pilot-scale combustors utilising the bubbling fluidised bed technology, and, theoretically, by means of reactor model calculations. The core of the model is a thermodynamic equilibrium analysis. The experiments were carried out with wood chips, sawdust, and peat, and their refuse-derived fuel, RDF, blends. In all, ten different fuels or fuel blends were tested. Relatively high concentrations of trace metals in RDFs compared to the concentrations of these metals in wood fuels increased the trace metal concentrations in the flue gas after the boiler ten- to hundred-folds, when RDF was co-fired with sawdust in a full-scale BFB boiler. In the case of peat, lesser increase in trace metal concentrations was observed, due to the higher initial trace metal concentrations of peat compared to sawdust. Despite the high removal rate of most of the trace metals in the ESP, the Directive emission limits for trace metals were exceeded in each of the RDF co-firing tests. The dominat trace metals in fluegas after the ESP were Cu, Pb and Mn. In the condensing wet scrubber, the flue gas trace metal emissions were reduced below the Directive emission limits, whenRDF pellet was used as a co-firing fuel together with sawdust and peat. High chlorine content of the RDFs enhanced the mercuric chloride formation and hence the mercury removal in the ESP and scrubber. Mercury emissions were lower than theDirective emission limit for total Hg, 0.05 mg/Nm3, in all full-scale co-firingtests already in the flue gas after the ESP. The pilot-scale experiments with aBFB combustor equipped with a fabric filter revealed that the fabric filter alone is able to reduce the trace metal concentrations, including mercury, in the flue gas during the RDF co-firing approximately to the same level as they are during the wood chip firing. Lower trace metal emissions than the Directive limits were easily reached even with a 40% thermal share of RDF co-firing with sawdust.Enrichment of trace metals in the submicron fly ash particle fraction because of RDF co-firing was not observed in the test runs where sawdust was used as the main fuel. The combustion of RDF pellets with peat caused an enrichment of As, Cd, Co, Pb, Sb, and V in the submicron particle mode. Accumulation and release oftrace metals in the bed material was examined by means of a bed material analysis, mass balance calculations and a reactor model. Lead, zinc and copper were found to have a tendency to be accumulated in the bed material but also to have a tendency to be released from the bed material into the combustion gases, if the combustion conditions were changed. The concentration of the trace metal in the combustion gases of the bubbling fluidised bed boiler was found to be a summary of trace metal fluxes from three main sources. They were (1) the trace metal flux from the burning fuel particle (2) the trace metal flux from the ash in the bed, and (3) the trace metal flux from the active alkali metal layer on the sand (and ash) particles in the bed. The amount of chlorine in the system, the combustion temperature, the fuel ash composition and the saturation state of the bed material in regard to trace metals were discovered to be key factors affecting therelease process. During the co-firing of waste fuels with variable amounts of e.g. ash and chlorine, it is extremely important to consider the possible ongoingaccumulation and/or release of the trace metals in the bed, when determining the flue gas trace metal emissions. If the state of the combustion process in regard to trace metals accumulation and/or release in the bed material is not known,it may happen that emissions from the bed material rather than the combustion of the fuel in question are measured and reported.