13 research outputs found

    Critical Behavior of the Ferromagnetic Ising Model on a Sierpinski Carpet: Monte Carlo Renormalization Group Study

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    We perform a Monte Carlo Renormalization Group analysis of the critical behavior of the ferromagnetic Ising model on a Sierpi\'nski fractal with Hausdorff dimension df≃1.8928d_f\simeq 1.8928. This method is shown to be relevant to the calculation of the critical temperature TcT_c and the magnetic eigen-exponent yhy_h on such structures. On the other hand, scaling corrections hinder the calculation of the temperature eigen-exponent yty_t. At last, the results are shown to be consistent with a finite size scaling analysis.Comment: 16 pages, 7 figure

    L'Hydroptère: A story of a dream

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    In 2009, l’Hydroptère broke the symbolic barrier of 50 knots and became the world fastest sailing boat over both 500 meters and 1 nautical mile. This major achievement relied on the high skills of the sailing team but also on technical advances of the boat, resulting from long years of studies and development. This achievement is also an open window to a new goal: flying around the world. In the present article, we present this long and incredible story, highlighting the different steps, the technology involved, and the background of that project.

    Hypoxia inducible factor 1α gene (HIF-1α) splice variants: potential prognostic biomarkers in breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Hypoxia-inducible factor 1 (HIF-1) is a master transcriptional regulator of genes regulating oxygen homeostasis. The HIF-1 protein is composed of two HIF-1α and HIF-1β/aryl hydrocarbon receptor nuclear translocator (ARNT) subunits. The prognostic relevance of HIF-1α protein overexpression has been shown in breast cancer. The impact of HIF-1α alternative splice variant expression on breast cancer prognosis in terms of metastasis risk is not well known.</p> <p>Methods</p> <p>Using real-time quantitative reverse transcription PCR assays, we measured mRNA concentrations of total <it>HIF-1α </it>and 4 variants in breast tissue specimens in a series of 29 normal tissues or benign lesions (normal/benign) and 53 primary carcinomas. In breast cancers <it>HIF-1α </it>splice variant levels were compared to clinicopathological parameters including tumour microvessel density and metastasis-free survival.</p> <p>Results</p> <p><it>HIF-1α </it>isoforms containing a three base pairs TAG insertion between exon 1 and exon 2 (designated <it>HIF-1α</it><sup><it>TAG</it></sup>) and <it>HIF-1α</it><sup><it>736 </it></sup>mRNAs were found expressed at higher levels in oestrogen receptor (OR)-negative carcinomas compared to normal/benign tissues (<it>P </it>= 0.009 and <it>P </it>= 0.004 respectively). In breast carcinoma specimens, lymph node status was significantly associated with <it>HIF-1α</it><sup><it>TAG </it></sup>mRNA levels (<it>P </it>= 0.037). Significant statistical association was found between tumour grade and <it>HIF-1α</it><sup><it>TAG </it></sup>(<it>P </it>= 0.048), and total <it>HIF-1α </it>(<it>P </it>= 0.048) mRNA levels. <it>HIF-1α</it><sup><it>TAG </it></sup>mRNA levels were also inversely correlated with both oestrogen and progesterone receptor status (<it>P </it>= 0.005 and <it>P </it>= 0.033 respectively). Univariate analysis showed that high <it>HIF-1α</it><sup><it>TAG </it></sup>mRNA levels correlated with shortened metastasis free survival (<it>P </it>= 0.01).</p> <p>Conclusions</p> <p>Our results show for the first time that mRNA expression of a <it>HIF-1α</it><sup><it>TAG </it></sup>splice variant reflects a stage of breast cancer progression and is associated with a worse prognosis.</p> <p>See commentary: <url>http://www.biomedcentral.com/1741-7015/8/45</url></p

    Prise en charge de 2 formes particulières de cancers du sein (les cancers colloïdes et médullaires)

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    AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    L’atome entouré, entité de base d’un modèle quasichimique de solution binaire

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    Le modèle en « atomes entourés » associé à une hypothèse de variation parabolique de l’énergie potentielle d’un atome en fonction de la composition de son entourage dépend de deux paramètres ajustables α et β. Le présent texte expose la façon de les déterminer, en ajustant les courbes d’enthalpie de mélange partielle ou intégrale sur l’ensemble des données expérimentales; la qualité de cette représentation est discutée. En outre par l’analyse de la collection des couples (α, β) obtenus pour 38 cas, un classement des systèmes métalliques liquides binaires est proposé

    Topiramate in childhood epileptic encephalopathy with continuous spike-waves during sleep: A retrospective study of 21 cases.

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    OBJECTIVE: Encephalopathy with continuous spike-wave during sleep (CSWS) is a particularly difficult-to-treat childhood epileptic syndrome. This study sought to present the EEG improvement and clinical efficacy of topiramate (TPM), a broad spectrum antiepileptic drug (AED), in a series of 21 children with CSWS encephalopathy. METHODS: We retrospectively reviewed the EEG results and clinical data of children with CSWS followed-up in our institution and treated with TPM. Sleep EEGs were performed 0-3 months prior to TPM introduction and then at 3 and 12 months. The exclusion criteria were (1) introduction of another AED and (2) withdrawal of a potentially aggravating AED during the first 3 months of treatment. In addition to spike index (SI), the severity of EEG abnormalities was rated using an original scale that also considered the spatial extent of interictal epileptiform discharges. RESULTS: 21 patients were included (18 males, 4-14y, three symptomatic cases). At 3 months, sleep EEG was improved in 14 and normalized in four (TPM doses: 2-5.5 mg/kg/day). Among these 18 patients, 16 manifested cognitive or behavioural improvement. In a subgroup of seven patients with frequent seizures, five became seizure-free and one had over 75% decrease in seizure frequency. At the one-year follow-up, 20 children were still on TPM and 10 exhibited persistent EEG improvement without any other AED being introduced, most of them with clinical benefits. CONCLUSION: TPM can decrease EEG abnormalities in epileptic encephalopathy with CSWS, achieving clinical improvement in the majority of patients. However, relapse may occur in the long-term in nearly half of cases. Otherwise, TPM has proven particularly useful in reducing seizure frequency in refractory cases

    Novel approaches towards the LTD4/e4 antagonist, LY290154

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    Several novel approaches have been investigated for the synthesis of the LTD4/E-4 antagonist LY290154. Significant improvements to the discovery route were first made by using an indoline nucleophile instead of an indolyl anion in the key substitution step. An alternative approach, introducing the 7-chloroquinoline moiety in the latest stages of the synthesis was then demonstrated. Interestingly, the pivotal intermediate of this latter route was also obtained in a one-pot process following a Katritzky methodology. Finally, an asymmetric synthesis offering significant advantages over the enantioselective route reported by McKillop was demonstrated
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