Evolution vers une sclérose en plaques après un premier événement démyélinisant (intérêt des potentiels évoqués somesthésiques et moteurs)

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Improvement of tensile strength of weld lines of a short carbon fiber reinforced PEEK using different overflow tabs configurations

International audienc

Long-term creep behavior of a short carbon fiber-reinforced PEEK at high temperature: Experimental and modeling approach

International audienceIn this work, the time-dependent mechanical behavior of a short carbon fiber-reinforced PEEK is investigated at temperatures near and above the glass transition temperature and for stresses below the damage threshold. An experimental procedure including creep/recovery tests and dynamic mechanical tests was carried out by varying stress levels, temperatures and fiber orientation. The mechanical behavior is shown to be linear viscoelastic below the damage threshold. Effect of the fiber orientation on elastic and viscoelastic behavior is similar. A procedure involving the time–temperature superposition principle (TTSP) is set to assess the long-term linear viscoelastic behavior and is shown to provide reliable results. A Maxwell Generalized model is used for unidirectional identification of the model’s parameters. It is then implemented via a UMAT in Abaqus with failure criteria for viscoelastic materials from the literature for 3D calculation of industrial parts

Evolution de la structure d'un composite PEEK renforcé de fibres de carbone courtes après vieillissement sous air

National audienc

Long term creep behavior of a short carbon fiber reinforced peek at high temperature

International audienceShort carbon fiber reinforced high performance thermoplastics, like poly (ether ether ketone) (PEEK), are materials very interesting for high temperature application. However, long term creep behaviour of this kind of material is still ill known. In this study, both quasi-static and dynamic mechanical testing are used to characterized short term and long term creep respectively at 150°C. The material is shown to behave linear viscoelastically for stresses below its elastic limit. Then a linear viscoelastic model is identified. Long term creep compliance is obtained via the time temperature superposition principle (TTSP) and well described with a Prony series. Moreover, this method allows effect of temperature and ageing determination. Nevertheless, the model underestimates viscoelastic strain if used to simulate multi steps creep/recovery tests

Administration of eptifibatide during endovascular treatment of ruptured cerebral aneurysms reduces the rate of thromboembolic events

International audienceIntroduction Thromboembolic complications are the most frequent complications of endovascular treatment of ruptured intracranial aneurysms. The optimal protocol to prevent thromboembolic complications during coil embolization does not yet exist. The aim of this study was to investigate the effectiveness and safety of eptifibatide for the prevention of thromboembolic complications during elective coil emboliza-tion of ruptured cerebral aneurysms. Methods A consecutive series of 100 patients (group 1) with ruptured intracranial aneurysm were treated using endovascular coil embolization. At the beginning of the procedure , all patients received an intra-arterial bolus (0.2 mg/kg) of eptifibatide. The following data were collected: degree of aneurysmal occlusion after treatment, thromboembolic and hemorrhagic complications and other intraoperative adverse events. The results were compared with those from a control group (group 2) which were analyzed retrospectively. Group 2 consisted of 100 previous patients with ruptured aneurysm managed with coil embolization who had received heparin and/or aspirin at the beginning of the procedure. Results (1) Patient populations in groups 1 and 2 were considered statistically comparable, except that group 1 (eptifibatide) included more wide-necked aneurysms (p=0.011). (2) There were less thromboembolic complications in group 1 (p=0.011): seven intraoperative complications in group 1 versus 20 in group 2. (3) Intraoperative hemorrhagic complications were statistically comparable in both groups (p=1). Conclusion Eptifibatide was effective in lowering the intra-operative thromboembolic complication rate in ruptured an-eurysms treated with coil embolization and did not increase the hemorrhagic risk

Premières données sur le site mésolithique du “Collège Belrem” à Beaurainville (Pas-de-Calais)

National audienc