Temperature dependence of second-order nonlinear relaxation of a poled chromophore doped sol-gel material

International audienceSecond-order optical nonlinearity relaxations of hybrid inorganic/organic sol-gel films doped with poled Disperse Red 1 chromophores were measured by second harmonic generation at several temperatures. The decay curves were fitted to biexponentials and Ko¨hlrausch, Williams, and Watts ~KWW! stretched exponentials. It can be concluded that the KWW model well describes chromophore thermal reorientation in hybrid sol-gel materials, as is known for all-organic polymers. Using the Arrhenius law, the activation energy of the reorientation process has been determined to be about 50 or 70 kcal mol21. A stability of roughly a decade has been extrapolated at room temperature. Another experiment at room temperature gave an estimation of the stability that was found to be in qualitative agreement. It is shown that poled chromophore-doped sol-gel materials have the potential to be stable enough for applications in telecommunication device

Assessment of the MERS-CoV epidemic situation in the Middle East region

The appearance of a novel coronavirus named Middle East (ME) Respiratory Syndrome Coronavirus (MERS-CoV) has raised global public health concerns regarding the current situation and its future evolution. Here we propose an integrative maximum likelihood analysis of both cluster data in the ME region and importations in Europe to assess transmission scenario and incidence of sporadic infections. Our approach is based on a spatial-transmission model integrating mobility data worldwide and allows for variations in the zoonotic/environmental transmission and underascertainment. Maximum likelihood estimates for the ME region indicate the occurrence of a subcritical epidemic (R=0.50, 95% confidence interval (CI) 0.30-0.77) associated with a 0.28 (95% CI 0.12-0.85) daily rate of sporadic introductions. Infections in the region appear to be mainly dominated by zoonotic/environmental transmissions, with possible underascertainment (95% CI of estimated to observed sporadic cases in the range 1.03-7.32). No time evolution of the situation emerges. Analyses of flight passenger data from the region indicate areas at high risk of importation. While dismissing an immediate threat for global health security, this analysis provides a baseline scenario for future reference and updates, suggests reinforced surveillance to limit underascertainment, and calls for increased alertness in high-risk areas worldwide.Comment: in press on Eurosurveillance, 16 pages, 3 figure

Stable photorefractive memory effect in sol-gel materials

International audienceWe report on the synthesis and the optical characterization of a photorefractive sol-gel material which contains nonlinear azo chromophore and carbazole charge transporting molecules. Both of these functional groups are covalently attached to the silica based backbone. Thin sol-gel films exhibit stable optically nonlinear properties: the electro-optic coefficient r13 measured at 633 nm is found to be 17 pm/V one day after corona poling and 15 pm/V after three weeks and over a period of several months. Photorefractivity is demonstrated by two beam coupling experiments without external applied electric field. Sol-gel films present a stable photorefractive memory effect with a net internal gain of 200 cm-

DR1 doped sol-gel planar waveguides for nonlinear devices operating at telecommunications wavelengths

International audienceWe report on linear and nonlinear optical properties of Disperse Red 1-doped solgel waveguides. The refractive-index and optical-propagation losses of the guiding layer were measured between 0.756 mm and 1.64 mm. The spectral broadening of the chromophore charge-transfer transition in the visible is modeled with a Voigt-profile function. In the telecommunications window the attenuation is dominated by the overtones of the O--H bonds vibration bands. The nonlinear optical coefficients were measured at different poling strengths with the Maker-fringe method. The nonlinear coefficient d33 was found to be 4.5 pm V21 at 1.58 mm for a poling field of 60 Vmm21

Pericardial effusion as the only manifestation of infection with Francisella tularensis: a case report

<p>Abstract</p> <p>Introduction</p> <p><it>Francisella tularensis</it>, a facultative intracellular Gram-negative bacterium, has rarely been reported as an agent of pericarditis, generally described as a complication of tularemia sepsis. <it>F. tularensis </it>is a fastidious organism that grows poorly on standard culture media and diagnosis is usually based on serological tests. However, cross-reactions may occur. Western blotting allows the correct diagnosis.</p> <p>Case presentation</p> <p>A non-smoking 53-year-old woman was admitted to hospital with a large posterior pericardial effusion. Serological tests showed a seroconversion in antibody titers to <it>F. tularensis </it>(IgG titer = 400) and <it>Legionella pneumophila </it>(IgG titer = 512). <it>F. tularensis </it>was identified by Western immunoblotting following cross-adsorption. The patient reported close contact with rabbits 2 weeks prior to the beginning of symptoms of pericarditis.</p> <p>Conclusion</p> <p>We report a rare case of pericardial effusion as the only manifestation of infection by <it>F. tularensis</it>. The etiological diagnosis is based on serology. Western blotting and cross-adsorption allow differential diagnosis.</p

Botulinum toxin use in patients with post-stroke spasticity: a nationwide retrospective study from France

BackgroundCurrent guidelines recommend intramuscular botulinum toxin type A (BoNT-A) injection as first-line treatment for spasticity, a frequent and impairing feature of various central nervous system (CNS) lesions such as stroke. Patients with spasticity commonly require BoNT-A injections once every 3 to 4 months. We conducted a nationwide, population-based, retrospective cohort study, using the French National Hospital Discharge Database (PMSI), to describe BoNT-A use for spasticity in clinical practice in France between 2014 and 2020. The PMSI database covers the whole French population, corresponding to over 66 million persons.MethodsWe first searched the PMSI database for healthcare facility discharge of patients who received BoNT-A injections between 2014 and 2020, corresponding to the first set. For each BoNT-A-treated patient, we identified the medical condition for which BoNT-A may have been indicated. Another search of the PMSI database focused on patients admitted for acute stroke between 2014 and 2016 and their spasticity-related care pathway (second set). Overall, two subpopulations were analysed: 138,481 patients who received BoNT-A injections between 2014 and 2020, and 318,025 patients who survived a stroke event between 2014 and 2016 and were followed up until 2020.ResultsAmong the 138,481 BoNT-A-treated patients, 53.5% received only one or two BoNT-A injections. Most of these patients (N = 85,900; 62.0%) received BoNT-A because they had CNS lesions. The number of patients with CNS lesions who received ≥1 BoNT-A injection increased by a mean of 7.5% per year from 2014 to 2019, but decreased by 0.2% between 2019 and 2020, corresponding to the COVID-19 outbreak. In stroke survivors (N = 318,025), 10.7% were coded with post-stroke spasticity, 2.3% received ≥1 BoNT-A injection between 2014 and 2020, and only 0.8% received ≥3 injections within the 12 months following BoNT-A treatment initiation, i.e., once every 3 to 4 months.ConclusionOur analysis of the exhaustive PMSI database showed a suboptimal implementation of BoNT-A treatment recommendations in France. BoNT-A treatment initiation and re-administration are low, particularly in patients with post-stroke spasticity. Further investigations may help explain this observation, and may target specific actions to improve spasticity-related care pathway

Un Christ roman auvergnat retrouve son unité grâce à l’étude de la polychromie

Le Metropolitan Museum of Art de New York et le musée du Louvre à Paris possèdent respectivement un torse et une tête de Christ roman auvergnat. L’appartenance de ces deux fragments à une seule et même œuvre a été largement discutée. L’étude approfondie de la structure et surtout de la polychromie des deux éléments (la polychromie originale comme les nombreux repeints) semble lever définitivement le doute en faveur de l’homogénéité de l’ensemble.The Metropolitan Museum of Art, New York, and the Louvre, Paris, respectively possess a torso and head of a Romanesque sculpture of Christ made in Auvergne. Whether these two fragments belong to the same statue has been the subject of much discussion. The in-depth study of the structure and, above all, of the polychromy of the two fragments (both the original polychromy and numerous repainted areas) seems to have finally lifted all doubts and conclusively determined that they are from the same work