Identification du couplage électro-élastique à partir de mesures de champs régularisées par les conditions d'équilibre

Les capteurs micromécaniques présentent de grands intérêts dans les domaines de la biologie et chimie. Leur stimulation électrochimique permet d'améliorer la mesure de flexion induite par l'adsorption de molécules ainsi que la reproductibilité des mesures. On modélise ici le couplage électro-élastique par une couche virtuelle d'épaisseur très petite devant celle du levier et contrainte à se déformer avec celui-ci. Afin de déterminer les paramètres mécaniques de ce système une méthode d'identification et régularisation à partir de mesures de champs est proposée

Low pressure carbon dioxide solubility in pure electrolyte solvents for lithium-ion batteries as a function of temperature. Measurement and prediction

Experimental values for the carbon dioxide solubility in eight pure electrolyte solvents for lithium ion batteries – such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), ?-butyrolactone (?BL), ethyl acetate (EA) and methyl propionate (MP) – are reported as a function of temperature from (283 to 353) K and atmospheric pressure. Based on experimental solubility data, the Henry’s law constant of the carbon dioxide in these solvents was then deduced and compared with reported values from the literature, as well as with those predicted by using COSMO-RS methodology within COSMOthermX software and those calculated by the Peng–Robinson equation of state implemented into Aspen plus. From this work, it appears that the CO2 solubility is higher in linear carbonates (such as DMC, EMC, DEC) than in cyclic ones (EC, PC, ?BL). Furthermore, the highest CO2 solubility was obtained in MP and EA solvents, which are comparable to the solubility values reported in classical ionicliquids. The precision and accuracy of the experimental values, considered as the per cent of the relative average absolute deviations of the Henry’s law constants from appropriate smoothing equations and from literature values, are close to (1% and 15%), respectively. From the variation of the Henry’s law constants with temperature, the partial molar thermodynamic functions of dissolution such as the standard Gibbs free energy, the enthalpy, and the entropy are calculated, as well as the mixing enthalpy of the solvent with CO2 in its hypothetical liquid state

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Business performance and angels presence: a fresh lookfrom France 2008–2011

International audienceAbstract Business angels enjoy a strong reputation forbeing more efficient than other investors among policymakers, practitioners, and scholars. However, due to thelimited availability of specific financial data, previousresearch has barely assessed the impact of angels oncompanies’ performance. This paper seeks to bridge thisgap by providing evidence from a unique dataset madeup of 432 angel-backed French companies which arecompared to two control groups, one randomly selectedand another one consisting of similar enterprises. Thisdouble comparison process enables us to purge ouranalysis of structural effect and to demonstrate the importanceof the methodology in generating the sample.Indeed, the results we obtain significantly differ dependingon the control group. Our results show that thepositive influence of angels depends on the conditionof the comparison. The set of BA-backed companies ismore likely to exhibit superior performance when it iscompared to a random sample whereas the companies’performance is either identical or worse when it iscompared to a sample composed of k-nearest neighbors.In addition, using a quantile regression technique makesit possible to differentiate the effect of business angelsbased on the distribution of the value of the growth rate

Business performance and angels presence: a fresh lookfrom France 2008–2011

International audienceAbstract Business angels enjoy a strong reputation forbeing more efficient than other investors among policymakers, practitioners, and scholars. However, due to thelimited availability of specific financial data, previousresearch has barely assessed the impact of angels oncompanies’ performance. This paper seeks to bridge thisgap by providing evidence from a unique dataset madeup of 432 angel-backed French companies which arecompared to two control groups, one randomly selectedand another one consisting of similar enterprises. Thisdouble comparison process enables us to purge ouranalysis of structural effect and to demonstrate the importanceof the methodology in generating the sample.Indeed, the results we obtain significantly differ dependingon the control group. Our results show that thepositive influence of angels depends on the conditionof the comparison. The set of BA-backed companies ismore likely to exhibit superior performance when it iscompared to a random sample whereas the companies’performance is either identical or worse when it iscompared to a sample composed of k-nearest neighbors.In addition, using a quantile regression technique makesit possible to differentiate the effect of business angelsbased on the distribution of the value of the growth rate

Étude de la stabilité de levures probiotiques au cours de la fabrication des aliments composés (conséquences pratiques pour leur utilisation en alimentation animale)

NANTES-BU Sciences (441092104) / SudocNANTES-Ecole Centrale (441092306) / SudocSudocFranceF

Phytothérapie et migraine

La physiopathologie de la migraine repose sur une composante neurogène et vasculaire associée à une perturbation de la sérotonine plaquettaire aboutissant à une inflammation neurogène. Les quatre plantes à vertus anti-migraineuses étudiées ont toutes en commun des propriétés anti-inflammatoires et anti-plaquettaires qui expliquent leur activité. La grande camomille est une herbe aromatique dont l'efficacité dans la prévention des crises migraineuses a été démontrée grâce à des études cliniques mais dont la toxicité chez l'homme n'est pas à négliger. Ces propriétés sont principalement dues aux lactones sesquiterpéniques contenues dans les sommités fleuries. Le gingembre est une épice communément utilisée en médecine traditionnelle orientale. Ces principes actifs, tous contenus dans la résine, sont principalement représentés par les gingérols et leurs produits dérivés. Quant au saule et à la reine des prés, ce sont des plantes contenant des dérivés salicylés, ancêtres de l'aspirine, mais qui à l'opposé de cette dernière ne possèdent pas d'effets délétères digestifs.NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

Phototoxicité de l'hypéricine (intérêt potentiel en photothérapie anticancéreuse et risques liés au traitement par le millepertuis)

PARIS-BIUP (751062107) / SudocSudocFranceF

Influence substituted zinc on stacking faults in nickel hydroxide

The evolution of the structure of zinc-substituted nickel hydroxides (alpha or beta phases) during ageing in the KOH electrolytic medium was studied..