129 research outputs found

    Magnetic properties of exchange biased and of unbiased oxide/permalloy thin layers: a ferromagnetic resonance and Brillouin scattering study

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    Microstrip ferromagnetic resonance and Brillouin scattering are used to provide a comparative determination of the magnetic parameters of thin permalloy layers interfaced with a non-magnetic (Al2O3) or with an antiferromagnetic oxide (NiO). It is shown that the perpendicular anisotropy is monitored by an interfacial surface energy term which is practically independent of the nature of the interface. In the investigated interval of thicknesses (5-25 nm) the saturation magnetisation does not significantly differ from the reported one in bulk permalloy. In-plane uniaxial anisotropy and exchange-bias anisotropy are also derived from this study of the dynamic magnetic excitations and compared to our independent evaluations using conventional magnetometryComment: 7 pages, 6 figures, submited to Journal of Physics: Condensed Matte

    Évolution des cancers de l’œsophage : impact de la stratégie thérapeutique

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    PURPOSE: To assess the outcome of esophageal cancer according to therapeutic strategy. PATIENTS AND METHODS: One-hundred and twenty patients with esophageal cancer treated by an association of radiotherapy and chemotherapy and possibly surgery, between 2004 and 2010, were retrospectively studied. The first site of relapse was classified as follows: local (tumour), locoregional (tumour and/or nodal: celiac, mediastinal, sus-clavicular) or metastatic. RESULTS: With a 15.7-months (1.4-62) median follow-up, there were 89 deaths and 79 recurrences. Three types of treatments were performed: 50Gy exclusive chemoradiotherapy (47 patients) or 50 to 65Gy exclusive chemoradiotherapy (44 patients) or chemoradiotherapy followed by surgery (27 patients). The local first relapse was as much frequent as distant relapse (50 patients). With a-5cm margin up and down to the tumour, there was only one nodal relapse. Two-year survival was 39.5% (95% confidence interval [IC]: 30.5-40.8) and relapse-free survival was 26.5% (CI: 18.6-35). Multivariate analysis revealed that treatment type and disease stage had a significant impact on survival, relapse-free survival and locoregional control. Compared to exclusive chemoradiotherapy, surgery improved locoregional control (40.2 versus 8.7 months, P=0.0004) but in a younger population. Despite postoperative mortality, the gain was maintained for distance relapse-free survival (40.2 versus 10 months, P=0.0147) and overall survival (29.3 versus 14.2 months, P=0.0088). Compared to 50Gy chemoradiotherapy, local control was improved if high dose chemoradiotherapy was performed (13.8 versus 7.5 months, P=0.05) but not overall survival (14.0 versus 15.4 months, P=0.24). CONCLUSION: More than one-third relapse is local. Locoregional control is better with high dose chemoradiotherapy. In this study, surgery performed in selected patients only, improved locoregional control, relapse-free disease and overall survival

    Seizures as an early symptom of autosomal dominant Alzheimer's disease

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    Our objective was to assess the reported history of seizures in cognitively asymptomatic mutation carriers for autosomal dominant Alzheimer's disease (ADAD) and the predictive value of seizures for mutation carrier status in cognitively asymptomatic first-degree relatives of ADAD patients. Seizure occurrence in the Dominantly Inherited Alzheimer Network observational study was correlated with mutation carrier status in cognitively asymptomatic subjects. Of 276 cognitively asymptomatic individuals, 11 (4%) had experienced seizures, and nine of these carried an ADAD mutation. Thus, in the Dominantly Inherited Alzheimer Network population, seizure frequency in mutation carriers was significantly higher than in noncarriers (p = 0.04), and the positive predictive value of seizures for the presence of a pathogenic mutation was 81.8%. Among cognitively asymptomatic ADAD family members, the occurrence of seizures increases the a priori risk of 50% mutation-positive status to about 80%. This finding suggests that ADAD mutations increase the risk of seizures

    Application of advanced (S)TEM methods for the study of nanostructured porous functional surfaces: A few working examples

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    Nanostructured films offer the ability of modifying surface properties, even more, when they can generate layers with controlled porosity. The lower implicit integrity of these (multi)layers when compared to their compact counterparts, hinders the attainment of electron-transparent sections of submicron thicknesses (lamellae), which becomes one of the main reason for the scarcity of studies thorough (scanning-)transmission electron microscopy ((S)TEM). Aware of this opportunity, this report provides an overview of the possibilities offered by the application of a variety of (S)TEM techniques for the study of nanostructured and porous photonic surfaces. A few working examples are presented to illustrate the type of information that can be obtained in the case of mesoporous films prepared either by at oblique angles physical processes as well as nitride nanowire arrays prepared by epitaxy methods. It will be demonstrated that this approach enables the realization of several pioneering works, which are essential to complete the characterization of such porosity-controlled coatings. Topics as diverse as the preparation of electron-transparent specimens and the advanced characterization of their structures, morphologies, interfaces and compositions are addressed thanks to the implementation of new breakthroughs in (S)TEM, which allow to obtain high-resolution imaging, spectroscopies, or tomography, at both microscopic and nanoscopic levels. Finally, establishing (S)TEM as a reference tool for the advanced structural, chemical and morphological characterization of porous nanostructured skins, will open new horizons, providing better and new insights and thus allowing the optimization of the fabrication and design of such architectures

    Annotation analysis for testing drug safety signals using unstructured clinical notes

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    BackgroundThe electronic surveillance for adverse drug events is largely based upon the analysis of coded data from reporting systems. Yet, the vast majority of electronic health data lies embedded within the free text of clinical notes and is not gathered into centralized repositories. With the increasing access to large volumes of electronic medical data-in particular the clinical notes-it may be possible to computationally encode and to test drug safety signals in an active manner.ResultsWe describe the application of simple annotation tools on clinical text and the mining of the resulting annotations to compute the risk of getting a myocardial infarction for patients with rheumatoid arthritis that take Vioxx. Our analysis clearly reveals elevated risks for myocardial infarction in rheumatoid arthritis patients taking Vioxx (odds ratio 2.06) before 2005.ConclusionsOur results show that it is possible to apply annotation analysis methods for testing hypotheses about drug safety using electronic medical records

    Different rates of cognitive decline in autosomal dominant and late-onset Alzheimer disease

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    As prevention trials advance with autosomal dominant Alzheimer disease (ADAD) participants, understanding the similarities and differences between ADAD and "sporadic" late-onset AD (LOAD) is critical to determine generalizability of findings between these cohorts. Cognitive trajectories of ADAD mutation carriers (MCs) and autopsy-confirmed LOAD individuals were compared to address this question. Longitudinal rates of change on cognitive measures were compared in ADAD MCs (n = 310) and autopsy-confirmed LOAD participants (n = 163) before and after symptom onset (estimated/observed). LOAD participants declined more rapidly in the presymptomatic (preclinical) period and performed more poorly at symptom onset than ADAD participants on a cognitive composite. After symptom onset, however, the younger ADAD MCs declined more rapidly. The similar but not identical cognitive trajectories (declining but at different rates) for ADAD and LOAD suggest common AD pathologies but with some differences

    Neurobiology of rodent self-grooming and its value for translational neuroscience

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    Self-grooming is a complex innate behaviour with an evolutionarily conserved sequencing pattern and is one of the most frequently performed behavioural activities in rodents. In this Review, we discuss the neurobiology of rodent self-grooming, and we highlight studies of rodent models of neuropsychiatric disorders-including models of autism spectrum disorder and obsessive compulsive disorder-that have assessed self-grooming phenotypes. We suggest that rodent self-grooming may be a useful measure of repetitive behaviour in such models, and therefore of value to translational psychiatry. Assessment of rodent self-grooming may also be useful for understanding the neural circuits that are involved in complex sequential patterns of action.National Institutes of Health (U.S.) (Grant NS025529)National Institutes of Health (U.S.) (Grant HD028341)National Institutes of Health (U.S.) (Grant MH060379

    Parkinson's Disease: Basic Pathomechanisms and a Clinical Overview

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    PD is a common and a debilitating degenerative movement disorder. The number of patients is increasing worldwide and as yet there is no cure for the disease. The majority of existing treatments target motor symptom control. Over the last two decades the impact of the genetic contribution to PD has been appreciated. Significant discoveries have been made, which have advanced our understanding of the pathophysiological and molecular basis of PD. In this chapter we outline current knowledge of the clinical aspects of PD and the basic mechanistic understanding

    Analyse automatique des mots polylexicaux en norvégien

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