Energy stored during deformation of crystallizing TPU foams

International audienceThe hysteresis loop observed in the mechanical response of elastomers is classically assumed to be due to viscosity. In this study, a complete energy balance is carried out during cyclic deformation of compact and foamed crystallizing thermoplastic polyurethanes. Results show that viscosity is not the only phenomenon involved in the hysteresis loop formation: A significant part of the mechanical energy brought is not dissipated into heat and is stored by the material when the material changes its microstructure, typically when it is crystallizing. Some of this energy is released during unloading, when melting occurs, but with a different rate, which contributes to the hysteresis loop. The part of the mechanical energy stored by the material has been quantified through the γse ratio (Loukil et al. (2018) European Polymer Journal, 98, 448–455) to investigate the effects of the loading rate and the void volume fraction on the energetic response of thermoplastic polyurethane

Metalla-Assembled Electron-Rich Tweezers: Redox-Controlled Guest Release Through Supramolecular Dimerization

International audienc

Chiral Truxene‐Based Self‐Assembled Cages: Triple Interlocking and Supramolecular Chirogenesis

Incorporating chiral elements in host‐guest systems currently focuses much attention, which results from the major impact such structures may have onto a wide range of applications, from pharmaceuticals to materials science and beyond. Moreover, the development of multi‐responsive and ‐functional systems is highly desirable since they offer numerous benefits. In this context, we describe herein the construction of a metal‐driven self‐assembled cage that associates a chiral truxene‐based ligand and a bis‐ruthenium complex. The maximum separation between both facing chiral units in the assembly is fixed by the intermetallic distance within the lateral bis‐ruthenium complex (8.4 Å). The resulting chiral cavity was shown to encapsulate polyaromatic guest molecules, but also to afford a chiral triply interlocked [2]catenane structure. The formation of the latter occurs at high concentration, while its disassembly could be achieved by addition of a planar achiral molecule. Interestingly the latter exhibits induced circular dichroism signature when trapped within the chiral cavity, demonstrating the cage ability for inducing supramolecular chirogenesis.</p

WEB 2.0 : 15 ans déjà et après ? : 7 pistes pour réenchanter Internet !

International audienceEn 15 ans, le Web 2.0 a radicalement transformé notre façon de travailler, de consommer, de vendre, de communiquer… Les technologies (mobile et tablette, 3G ou 4G, médias sociaux, big data, IA, etc.) ont bouleversé nos sphères de vie et notre rapport aux individus, à l’information, aux objets… 57 pionniers vous proposent d’explorer rétrospectivement les conséquences du digital sur notre société (économie, politique, juridique, culturel…). Le but : imaginer 7 pistes de réenchantement pour un futur numérique plus sain et plus responsable face à la domination des géants d’Internet, GAFA et BATX.La voix de 57 pionniers : Farid Arab . Thierry de Baillon . Christine Balagué . Éric Barbry . Beer Bergman . Olivier Berlingué . Nicolas Bermond . Fanny Berrebi . Michelle Blanc . Jérôme Bondu . Fadhila Brahimi . Frédéric Canevet . Dominique Cardon . Nicolas Celic . Cyrille Chaudoit . Jean-Pierre Corniou . Céline Crespin . André Dan . Yannis Delmas-Rigoutsos . Damien Douani . Antoine Dubuquoy . Jean-Philippe Encausse . Fabrice Epelboin . Olivier Ezratty . Isabelle Falque-Pierrotin . David Fayon . Mathieu Flaig . Cyrille Frank . Yann Gourvennec . David Guillocheau . Claudie Haigneré (Préface) . Olivier Iteanu . Henri Kaufman (Postface) . François Laurent . Yann Leroux . Éric Maillard . Vérone Mankou . Émilie Marquois . Grégory Maubon . Pierre Mawas . Pierre Métivier . Jean-Claude Morand . Ahmed Mehdi Omarouayache . Anthony Poncier . Grégory Pouy . PPC . Benoît Raphaël . Cyril Rimbaud . Vincent Rostaing . Jean-François Ruiz . Éric Seulliet . Serge Soudoplatoff . Virginie Spies . Yaëlle Teicher Stein . Pierre Tran . Pierre Vallet . Henri Verdier

Persistent headaches one year after bacterial meningitis: prevalence, determinants and impact on quality of life

International audienceBackground: Little is known on headaches long-term persistence after bacterial meningitis and on their impact on patients' quality of life.Methods: In an ancillary study of the French national prospective cohort of community-acquired bacterial meningitis in adults (COMBAT) conducted between February 2013 and July 2015, we collected self-reported headaches before, at onset, and 12 months (M12) after meningitis. Determinants of persistent headache (PH) at M12, their association with M12 quality of life (SF 12), depression (Center for Epidemiologic Studies Depression Scale) and neuro-functional disability were analysed.Results: Among the 277 alive patients at M12 87/274 (31.8%), 213/271 (78.6%) and 86/277 (31.0%) reported headaches before, at the onset, and at M12, respectively. In multivariate analysis, female sex (OR: 2.75 [1.54-4.90]; p < 0.001), pre-existing headaches before meningitis (OR: 2.38 [1.32-4.30]; p < 0.01), higher neutrophilic polynuclei percentage in the CSF of the initial lumbar puncture (OR: 1.02 [1.00-1.04]; p < 0.05), and brain abscess during the initial hospitalisation (OR: 8.32 [1.97-35.16]; p < 0.01) were associated with M12 persistent headaches. Neither the responsible microorganism, nor the corticoids use were associated with M12 persistent headaches. M12 neuro-functional disability (altered Glasgow Outcome Scale; p < 0.01), M12 physical handicap (altered modified Rankin score; p < 0.001), M12 depressive symptoms (p < 0.0001), and M12 altered physical (p < 0.05) and mental (p < 0.0001) qualities of life were associated with M12 headaches.Conclusion: Persistent headaches are frequent one year after meningitis and are associated with quality of life alteration

One-Year Sequelae and Quality of Life in Adults with Meningococcal Meningitis: Lessons from the COMBAT Multicentre Prospective Study

Trial registration: ClinicalTrial.Gov identification number NCT01730690.International audienceIntroduction: COMBAT is a prospective, multicentre cohort study that enrolled consecutive adults with community-acquired bacterial meningitis (CABM) in 69 participating centres in France between February 2013 and July 2015 and followed them for 1 year.Methods: Patients aged at least 18 years old, hospitalised with CABM were followed during their hospitalisation and then contacted by phone 12 months after enrolment. Here we present the prevalence of sequelae at 12 months in a subgroup of patients with meningococcal meningitis.Results: Five of the 111 patients with meningococcal meningitis died during initial hospitalisation and two died between discharge and 12 months, leaving 104 patients alive 1 year after enrolment, 71 of whom provided 12-month follow-up data. The median age was 30.0 years and 54.1% of the patients had no identified risk factor for meningitis. More than 30% reported persistent headache, more than 40% were not satisfied with their sleep and 10% had concentration difficulties. Hearing loss was present in about 15% of the patients and more than 30% had depressive symptoms. About 13% of the patients with a previous professional activity had not resumed work. On the SF-12 Health Survey, almost 50% and 30% had physical component or mental component scores lower than the 25th percentile of the score distribution in the French general population. There was a non-significant improvement in the patients' disability scores from hospital discharge to 12 months (p = 0.16), but about 10% of the patients had residual disability.Conclusions: Although most patients in our cohort survive meningococcal meningitis, the long-term burden is substantial and therefore it is important to ensure a prolonged follow-up of survivors and to promote preventive strategies, including vaccination

Relationship between serotypes, disease characteristics and 30-day mortality in adults with invasive pneumococcal disease

International audienc

Evolution over Time of Ventilatory Management and Outcome of Patients with Neurologic Disease∗

OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p &lt; 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p &lt; 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p &lt; 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease