Psychomécanique appliquée aux Trains à Grande Vitesse

La psychomécanique est l'étude des interactions entre les paramètres mécaniques d'une structure vibrante, les paramètres acoustiques des signaux rayonnés et leur perception par un auditeur. Nous réalisons cette étude parallèlement sur deux systèmes : une voiture de TGV et sur un système plus académique constitué d'une cavité rigide fermée par une plaque mince vibrante. Ce système peut être représentatif d'un habitacle de véhicule. Nous cherchons alors à évaluer l'influence des paramètres de modélisation sur la perception. Le comportement vibroacoustique du système plaque/cavité est décrit par une méthode modale analytique et celui du TGV est décrit par une méthode modale expérimentale. Nous présentons les résultats de ces deux méthodes ainsi que ceux des premiers tests perceptifs

Formal semantics of behavior specifications in the architecture analysis and design language standard

In system design, an architecture specification or model serves, among other purposes, as a repository to share knowledge about the system being designed. Such a repository enables automatic generation of analytical models for different aspects relevant to system design (timing, reliability, security, etc.). The Architecture Analysis and Design Language (AADL) is a standard proposed by SAE to express architecture specifications and share knowledge between the different stakeholders about the system being designed. To support unambiguous reasoning, formal verification, high-fidelity simulation of architecture specifications in a model-based AADL design workflow, we have defined a formal semantics for the behavior specification of the AADL, the presentation of this semantics is the aim of this paper

Validation of the Body Scan®, a new device to detect small fiber neuropathy by assessment of the sudomotor function: agreement with the Sudoscan®

BackgroundSudomotor dysfunction is one of the earliest manifestations of small fiber neuropathy (SFN), reflecting the alteration of sympathetic C fiber innervation of the sweat glands. Among other techniques, such innervation can be assessed by measuring electrochemical skin conductance (ESC) in microsiemens (μS). In this study, ESC was measured at the feet to detect distal SFN. For this objective, the performance of a new device, the Body Scan® (Withings, France), intended for home use, was compared with that of a reference device, the Sudoscan® (Impeto Medical, France), which requires a hospital setting.MethodsIn patients with diabetes with or without neuropathy or non-diabetic patients with lower-limb neuropathy, the diagnostic performance of the Body Scan® measurement was assessed by calculating its sensitivity (Se) and specificity (Sp) to detect at least moderate SFN (Se70 and Sp70), defined by a value of feet ESC ≤ 70 μS and > 50 μS on the Sudoscan® measure, or severe SFN (Se50 and Sp50), defined by a value of feet ESC ≤ 50 μS on the Sudoscan® measure. The agreement between the two devices was assessed with the analysis of Bland–Altman plots, mean absolute error (MAE), and root mean squared error (RMSE) calculations. The repeatability of the measurements was also compared between the two devices.ResultsA total of 147 patients (52% men, mean age 59 years old, 76% diabetic) were included in the analysis. The sensitivity and specificity to detect at least moderate or severe SFN were: Se70 = 0.91 ([0.83, 0.96]), Sp70 = 0.97 ([0.88, 0.99]), Se50 = 0.91 ([0.80, 0.98]), and Sp50 = 0.99 ([0.94, 1]), respectively. The bias and 95% limits of agreement were 1.5 [−5.4, 8.4]. The MAE was 2.9 and the RMSE 3.8. The intra-sample variability was 2.0 for the Body Scan® and 2.3 for the Sudoscan®.ConclusionThe ESC measurements provided by the Body Scan® were in almost perfect agreement with those provided by the reference device, the Sudoscan®, which validates the accuracy of the Body Scan® for the detection of SFN. By enabling simple, rapid, and autonomous use by the patient at home, this new technique will facilitate screening and monitoring of SFN in daily practice.Clinical trial registrationClinicalTrials.gov, identifier NCT05178459

Evaluation of the Tobacco Heating System 2.2. Part 2: Chemical composition, genotoxicity, cytotoxicity, and physical properties of the aerosol

The chemical composition, in vitro genotoxicity, and cytotoxicity of the mainstream aerosol from the Tobacco Heating System 2.2 (THS2.2) were compared with those of the mainstream smoke from the 3R4F reference cigarette. In contrast to the 3R4F, the tobacco plug in the THS2.2 is not burnt. The low operating temperature of THS2.2 caused distinct shifts in the aerosol composition compared with 3R4F. This resulted in a reduction of more than 90% for the majority of the analyzed harmful and potentially harmful constituents (HPHCs), while the mass median aerodynamic diameter of the aerosol remained similar. A reduction of about 90% was also observed when comparing the cytotoxicity determined by the neutral red uptake assay and the mutagenic potency in the mouse lymphoma assay. The THS2.2 aerosol was not mutagenic in the Ames assay. The chemical composition of the THS2.2 aerosol was also evaluated under extreme climatic and puffing conditions. When generating the THS2.2 aerosol under “desert” or “tropical” conditions, the generation of HPHCs was not significantly modified. When using puffing regimens that were more intense than the standard Health Canada Intense (HCI) machinesmoking conditions, the HPHC yields remained lower than when smoking the 3R4F reference cigarette with the HCI regimen

Predictors of hospital discharge and mortality in patients with diabetes and COVID-19: updated results from the nationwide CORONADO study

AIMS/HYPOTHESIS: This is an update of the results from the previous report of the CORONADO (Coronavirus SARS-CoV-2 and Diabetes Outcomes) study, which aims to describe the outcomes and prognostic factors in patients with diabetes hospitalised for coronavirus disease-2019 (COVID-19). METHODS: The CORONADO initiative is a French nationwide multicentre study of patients with diabetes hospitalised for COVID-19 with a 28-day follow-up. The patients were screened after hospital admission from 10 March to 10 April 2020. We mainly focused on hospital discharge and death within 28 days. RESULTS: We included 2796 participants: 63.7% men, mean age 69.7 ± 13.2 years, median BMI (25th-75th percentile) 28.4 (25.0-32.4) kg/m(2). Microvascular and macrovascular diabetic complications were found in 44.2% and 38.6% of participants, respectively. Within 28 days, 1404 (50.2%; 95% CI 48.3%, 52.1%) were discharged from hospital with a median duration of hospital stay of 9 (5-14) days, while 577 participants died (20.6%; 95% CI 19.2%, 22.2%). In multivariable models, younger age, routine metformin therapy and longer symptom duration on admission were positively associated with discharge. History of microvascular complications, anticoagulant routine therapy, dyspnoea on admission, and higher aspartate aminotransferase, white cell count and C-reactive protein levels were associated with a reduced chance of discharge. Factors associated with death within 28 days mirrored those associated with discharge, and also included routine treatment by insulin and statin as deleterious factors. CONCLUSIONS/INTERPRETATION: In patients with diabetes hospitalised for COVID-19, we established prognostic factors for hospital discharge and death that could help clinicians in this pandemic period. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04324736

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Problèmes actuels en mécanique dans le domaine ferroviaire : vers l’omniprésence du non-linéaire et du stochastique

International audienceLes problèmes actuels en mécanique dans le domaine ferroviaire font intervenir de manière intensive des non linéarités, que ce soit dans le comportement des composants du système (ex. ballast…), ou aux interfaces. Par ailleurs, la prise en compte de l’aléatoire dans la modélisation devient incontournable, tant pour les sollicitations du système que pour la variabilité de ses caractéristiques. Ces deux tendances sont illustrées sur des exemples de problématiques actuelles : dynamique des véhicules et de l’infrastructure, crissement

Apport de l'échocardiographie trans-œsophagienne 3D temps réel dans l'analyse de la valve mitrale (étude prospective clermontoise)

L'objectif de notre travail est d'utiliser l'imagerie trois dimensions (3D) assistée du logiciel Mitral Valve Quantification (MVQ) pour améliorer la prise en charge chirurgicale des patients souffrant d'une insuffisance mitrale (IM). Cette étude prospective totalise 23 patients souffrant d'une IM chirurgicale et 8 patients contrôles sans pathologie mitrale. L'ensemble des patients a bénéficié d'un examen échocardiographique préopératoire trans-thoracique par l'opérateur n1 puis d'une échographie trans-œsophagienne (ETO) 2D et 3D l'opérateur n2. Une modélisation de la valve mitrale est ensuite réalisée grâce au logiciel MVQ par l'opérateur n3 sans connaître les résultats des précédents examens. Dans l'analyse des lésions valvulaires mitrales, on remarque que les précisions diagnostiques sont supérieures en ETO 3D par rapport à l'ETO 2D, elle même supérieure à l'ETT. C'est d'ailleurs pour l'exploration de P1, P3, des commissures, des atteintes univalvulaires et complexes que la différence semble la plus importante. Il existe une différence significative en faveur de l'ETO 3D dans la détection des prolapsus de P1, des atteintes commissurales et univalvulaires. Nous retrouvons une corrélation et une bonne concordance entre l'ETO 2 D et les données MVQ concernant les mesures des feuillets mitraux et de l'anneau (p<0,01). Nous avons pu montrer qu'il existe une corrélation entre les mesures préopératoire 3D de l'anneau et la taille des anneaux ou prothèses mis en place chirurgicalement (p<0,05). L'ETO 3D est d'autant plus pertinente que les lésions sont complexes et permet une analyse plus précise de cette valve comparée à l'échographie bidimentionnelle. L'évaluation en 3D et sa modélisation pourraient soutenir l'acte chirurgical en permettant une réparation "personnalisée" garantissant une meilleure restauration de la physiologie valvulaire mitrale.CLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

Mesure et modélisation des hétérogénéités de distribution du rayonnement magnétique des inductances toriques

International audienc