SOLID STATE BATTERIES WITH CONDUCTING POLYMERS

Les polymères conducteurs comme (CH)x sont très intéressants comme matériaux d'électrodes dans des cellules électrochimiques. Nous avons combiné de telles électrodes avec des électrolytes solides pour fabriquer des piles "tout solide". Les premiers prototypes utilisant une anode d'argent et un électrolyte solide à conduction Ag+ fonctionnent de façon satisfaisante depuis deux ans. Les performances ont été testées sur de nombreuses cellules pour étudier les propriétés électriques ainsi que les paramètres thermodynamiques. Un grand nombre de cycles charge-décharge ont été enregistrés à diverses valeurs de courant maintenu constant. Ceci a permis de déterminer les propriétés essentielles : tension, courant, densité de courant, fiabilité, rendement faradique, rendement énergétique, etc. Les performances ont été également étudiées en fonction de la température, permettant d'obtenir l'enthalpie et l'entropie de la réaction électrochimique. La cinétique de la décharge a été soigneusement mesurée et comparée aux données de diffusion récemment obtenues dans notre laboratoire à l'aide d'isotopes radioactifs. Ceci a donné une explication claire du mécanisme de transport atomique dans le polymère.The conducting polymers like (CH)x are very interesting materials for electrodes in electrochemical cells. We have combined such electrodes with solid electrolytes to build "all solid-state" batteries. The first prototypes using a silver anode and a silver conducting electrolyte have been working satisfactorily since two years. The performances have been tested with many batteries to study the electrical properties as well as the thermodynamical parameters. A number of cycles of charge-discharge have been recorded at various values of the current kept constant. This has allowed to determine the essential properties : voltage, current, current density, reliability, Faradaic and energetic efficiency ... The performances have also been investigated as a function of temperature, allowing to derive the enthalpy and the entropy of the electrochemical reaction. The kinetics of the discharge has been thorough-fully measured and compared to the mass transport data recently obtained in our laboratory by using radiotracers. This has given a clear explanation of the mechanism of mass transport inside the polymer

Accelerated surgery versus standard care in hip fracture (HIP ATTACK) : an international, randomised, controlled trial

Background: Observational studies have suggested that accelerated surgery is associated with improved outcomes in patients with a hip fracture. The HIP ATTACK trial assessed whether accelerated surgery could reduce mortality and major complications. Methods: HIP ATTACK was an international, randomised, controlled trial done at 69 hospitals in 17 countries. Patients with a hip fracture that required surgery and were aged 45 years or older were eligible. Research personnel randomly assigned patients (1:1) through a central computerised randomisation system using randomly varying block sizes to either accelerated surgery (goal of surgery within 6 h of diagnosis) or standard care. The coprimary outcomes were mortality and a composite of major complications (ie, mortality and non-fatal myocardial infarction, stroke, venous thromboembolism, sepsis, pneumonia, life-threatening bleeding, and major bleeding) at 90 days after randomisation. Patients, health-care providers, and study staff were aware of treatment assignment, but outcome adjudicators were masked to treatment allocation. Patients were analysed according to the intention-to-treat principle. This study is registered at ClinicalTrials.gov (NCT02027896). Findings: Between March 14, 2014, and May 24, 2019, 27 701 patients were screened, of whom 7780 were eligible. 2970 of these were enrolled and randomly assigned to receive accelerated surgery (n=1487) or standard care (n=1483). The median time from hip fracture diagnosis to surgery was 6 h (IQR 4\u20139) in the accelerated-surgery group and 24 h (10\u201342) in the standard-care group (p<0\ub70001). 140 (9%) patients assigned to accelerated surgery and 154 (10%) assigned to standard care died, with a hazard ratio (HR) of 0\ub791 (95% CI 0\ub772 to 1\ub714) and absolute risk reduction (ARR) of 1% ( 121 to 3; p=0\ub740). Major complications occurred in 321 (22%) patients assigned to accelerated surgery and 331 (22%) assigned to standard care, with an HR of 0\ub797 (0\ub783 to 1\ub713) and an ARR of 1% ( 122 to 4; p=0\ub771). Interpretation: Among patients with a hip fracture, accelerated surgery did not significantly lower the risk of mortality or a composite of major complications compared with standard care. Funding: Canadian Institutes of Health Research