Création d'une filière neuro-vasculaire au CHU de Tours (résultats à 18 mois )

TOURS-BU Médecine (372612103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Arguments permettant aux médecins d'évoquer le diagnostic d'AVC ou d'AIT en ambulatoire

TOURS-BU Médecine (372612103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Zac Borie/Jean Mermoz à Castelnau-le-Lez (Hérault)

Rapport

Rationale for the implementation of reference electrodes in ionic liquids

International audienceA thorough investigation of the reference electrodes for electrochemical measurements is presented in three ionic liquids (ILs), namely 1-butyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide [BMIM][Tf2N], 1-octyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide [OMIM][Tf2N] and 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide [BMPyrr][Tf2N]. The influence of technical aspects such as internal resistance, scan rate and concentration of the active species on cyclic voltammetry has been investigated using three quasi-reference electrodes (QREs) (AgCl, Pt, and Pd) and three reference electrodes (REs) (Fc+/Fc/Pt, Ag+/Ag, and Cl−/AgCl/Ag). The results show that the internal resistance has to be taken dynamically into account during any cyclic voltammetry experiment. Quasi-reference electrodes can be used only for qualitative electrochemical studies. Reference electrodes based on Ag+/Ag or Fc+/Fc dissolved in an IL have a stable potential over 15 h and thus can be used to perform reliable electrochemical experiments in ionic liquids and to get quantitative information such as potentials

Possibilities and limitations in separating Pt( iv ) from Pd( ii ) combining imidazolium and phosphonium ionic liquids

International audienceAn investigation on a process designed for separating Pt(IV) and Pd(II) dissolved in acidic aqueous solution containing HCl using two ionic liquids, 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([OMIM][NTf2]) and trihexyltetradecylphosphonium bromide (Cyphos 102), is presented. To this end, the single extraction of platinum in [OMIM][NTf2] has been investigated as a function of the initial concentration of Pt(IV) ions dissolved in 1 M HCl. The distribution coefficient for Pt(IV), present in water as a PtCl62− anion, decreases with the concentration of Pt(IV). The extraction of Pd(II) towards [OMIM][NTf2] or Cyphos 102 as a function of the concentration of HCl in the aqueous phase is also reported. Pd(II), present as PdCl42− in water, is not extracted using [OMIM][NTf2]. On the other hand, the distribution coefficients of Pd(II) using Cyphos 102 are above 2000. In this ionic liquid, Pd(II) is extracted as a PdBr42− anion. Separation of Pt(IV) from Pd(II) was then carried out starting from aqueous phases containing 1 M HCl and various initial concentrations of Pt(IV). The influence of the number of extraction steps using [OMIM][NTf2] on the extraction of Pt(IV) was also studied. Unlike the results obtained from single extraction experiments of Pt(IV), consecutive extraction of Pt(IV) in water using [OMIM][NTf2] does not improve significantly the extraction of this metal ion. The second step of the extraction process carried out using Cyphos 102 leads to the quantitative extraction of Pd(II) and Pt(IV) remaining in the aqueous phase

RhoA GTPase regulates radiation-induced alterations in endothelial cell adhesion and migration

International audienceEndothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiationinduced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15 Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial functions linked to actin cytoskeleton

Europange : les processus de rassemblements politiques. L’exemple de l’Europe angevine (XIIIe-XVe siècle)

Introduction L’Europe actuelle s’interroge sur les méthodes et les fondements de son processus d’intégration politique, sur la place des États et des régions au sein de ce dernier. Ces problèmes du temps présent questionnent les héritages et les processus séculaires qui ont forgé nos cultures politiques et administratives, pour lesquelles les trois derniers siècles du Moyen Âge constituent une étape déterminante. Ils renvoient ainsi l’historien aux lents mouvements de rassemblement qui ont co..