Combined Thoracic Ultrasound Assessment during a Successful Weaning Trial Predicts Postextubation Distress

International audienceBackground: Recent studies suggest that isolated sonographic assessment of the respiratory, cardiac, or neuromuscular functions in mechanically ventilated patients may assist in identifying patients at risk of postextubation distress. The aim of the present study was to prospectively investigate the value of an integrated thoracic ultrasound evaluation, encompassing bedside respiratory, cardiac, and diaphragm sonographic data in predicting postextubation distress.Methods: Longitudinal ultrasound data from 136 patients who were extubated after passing a trial of pressure support ventilation were measured immediately after the start and at the end of this trial. In case of postextubation distress (31 of 136 patients), an additional combined ultrasound assessment was performed while the patient was still in acute respiratory failure. We applied machine-learning methods to improve the accuracy of the related predictive assessments.Results: Overall, integrated thoracic ultrasound models accurately predict postextubation distress when applied to thoracic ultrasound data immediately recorded before the start and at the end of the trial of pressure support ventilation (learning sample area under the curve: start, 0.921; end, 0.951; test sample area under the curve: start, 0.972; end, 0.920). Among integrated thoracic ultrasound data, the recognition of lung interstitial edema and the increased telediastolic left ventricular pressure were the most relevant predictive factors. In addition, the use of thoracic ultrasound appeared to be highly accurate in identifying the causes of postextubation distress.Conclusions: The decision to attempt extubation could be significantly assisted by an integrative, dynamic, and fully bedside ultrasonographic assessment of cardiac, lung, and diaphragm functio

La greffe d'ébauches pancréatiques fœtales comme alternative thérapeutique dans le diabète de type 1

Ce travail a eu pour but d étudier la greffe d ébauches pancréatiques comme alternative thérapeutique dans le DT1. Chez certains patients, la greffe d îlots adultes peut être proposée, mais le manque de donneurs, l effet transitoire de la régulation de la glycémie, ainsi que l obligation de l utilisation d un traitement immunosuppresseur sont un frein à cette option thérapeutique. Les ébauches pancréatiques peuvent donc être une alternative thérapeutique intéressante, car elles peuvent être issues de sources abondantes comme les embryons de porc ou encore les embryons humains issus d IVG. De plus, la présence de cellules souches dans ces ébauches laisse entrevoir un effet à long terme sur la régulation de la glycémie. La bibliographie suggère également une plus faible immunogénicité des tissus fœtaux en comparaison de celle des tissus adultes. Après une phase de mise au point du protocole de greffe, nous avons pu déterminer qu en condition syngénique, 2 ébauches pancréatiques E12.5 étaient suffisantes pour réguler la glycémie de souris diabétiques. Parallèlement, un retard du développement des ébauches a été observé chez les receveurs mâles, par rapport aux receveurs femelles. Le rôle du système immunitaire ainsi que celui des hormones sexuelles et lactogènes ont ensuite été testés pour expliquer cette différence de développement selon le sexe des receveurs. Nos données suggèrent que la prolactine serait le facteur déterminant de cette différence en augmentant la prolifération des précurseurs des cellules beta. Finalement, l immunogénicité des ébauches pancréatiques dans différents types de disparités allogéniques (majeur, semi-allogénique et mineur) a été étudiée. Les résultats montrent que les ébauches pancréatiques sont rapidement rejetées, suite à la présence d un infiltrat majoritairement composé de lymphocytes T et de cellules myéloïdes. Ce travail suggère donc que les ébauches pancréatiques peuvent être une alternative thérapeutique intéressante dans le cadre du diabète de type 1, malgré la nécessité de l utilisation d un traitement immunosuppresseur.PARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Modélisation hydrologique et hydrochimique d'un petit bassin versant méditerranéen (conséquences de la variabilité hydrologique et d'un incendie de forêt (bassin du Rimbaud, Réal Collobrier, Var))

MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Représentativité à l'échelle d'un bassin versant des mesures chimiques prises dans un collecteur de pluie : un exemple dans le massif des Maures

Cet article a été publié en anglais dans la revue avec comité de lecture Hydrological Sciences Journal, vol. 47, n° 3, p. 469-478 : "What can be deduced from chemical measurements in an open-field rain-gauge ? An example in the Maures Massif in southeastern France".La mesure, au moyen d'un collecteur de pluie, des entrées d'éléments minéraux sur un bassin versant, est analysée à travers des données recueillies pendant cinq ans dans le massif des Maures. Une approche de bilan de chlorure montre que des dépôts occultes de cet élément non captés par le collecteur représentent près de la moitié des entrées à l'échelle du bassin. L'étude des relations entre les concentrations et les durées séparant les prélèvements met en évidence la contribution des dépôts par temps sec à la signature chimique des eaux recueillies. Cependant cette contribution ne représente qu'une partie, variable suivant les éléments, des dépôts à l'échelle du bassin. La mesure des entrées chimiques apparaît biaisée. Elle doit être considérée avec prudence, et donc croisée avec d'autres sources d'informations, telles que des analyses chimiques de l'égouttement sous les arbres

Should payment for performance depend on mortality?

International audienceThe introduction of the Hospital Value Based Purchasing (HVBP) programme, as shown recently by Jose F Figueroa and colleagues, did not improve 30 day mortality of Medicare beneficiaries admitted to US hospitals for three incentivised conditions. We agree with the authors’ conclusion that an “appropriate mix of quality metrics and incentives to improve patient outcomes” has yet to be identified.The programme was designed to promote better clinical outcomes for hospital patients and to improve their experience of care during hospital stays. However, if reducing mortality was the primary objective, a specific set of indicators should have been selected from relevant practice and organisational guidelines, which was not the case when the programme was designed. The absence of HVBP’s impact on mortality is therefore not surprising.In their conclusion Figueroa and colleagues say, “Nations considering similar pay for performance programs may want to consider alternative models.” This raises a question: should payment depend on achieving a decrease in mortality rates? The primary objective of pay for performance programmes could still be the development and maintenance of continuous quality improvement (CQI) programmes based on relevant process indicators to assess critical steps in patient management, such as the effective use of checklists in surgical procedures. These process indicators are apt to detect dangerous misconduct, less susceptible to bias, and more actionable.However, a problem remains: such CQI programmes in hospitals rely on a limited number of people repeatedly trying to motivate a large number of health professionals who are insensitive to the benefits of CQI. Instead of diverting the small percentage of budget devoted to pay for performance programmes it could be more profitable, for patients, to think of a better use for this money

Comparative study of electrochemical properties of mixed conducting Ln2NiO4+δ (Ln = La, Pr and Nd) and La0.6Sr0.4Fe0.8Co0.2O3−δ as SOFC cathodes associated to Ce0.9Gd0.1O2−δ, La0.8Sr0.2Ga0.8Mg0.2O3−δ and La9Sr1Si6O26.5 electrolytes

The present paper focuses on the comparative study of the electrochemical properties of various mixed conducting oxides used as cathode in alternative couples (cathode/electrolyte) with the aim to improve the performance of the usual couple based on LSM (La0.8Sr0.2MnO3)/YSZ (yttria stabilized zirconia). The oxygen deficient perovskite, La0.6Sr0.4Fe0.8Co0.2O3 − δ (LSFC) and the Ruddlesden-Popper phases, the nickelates Ln2NiO4 + δ (Ln = La, Pr and Nd) have been investigated as cathode materials for potential application in IT-SOFC systems, using various electrolyte materials such as cerium gadolinium oxide Ce0.9Gd0.1O2 − δ (CGO), substituted lanthanum gallate, La0.8Sr0.2Ga0.8Mg0.2O3 − δ (LSGM) and the apatite-type lanthanum silicate La9Sr1Si6O26.5 (LSSO). The chemical reactivity of cathode/electrolyte powder mixtures was investigated by XRD: the results revealed LSFC to have a good chemical compatibility with the various electrolytes while the nickelate oxides showed some reactivity and even a partial decomposition for Pr2NiO4 + δ. The electrochemical properties of these cathode materials have been investigated by impedance spectroscopy under zero dc conditions. The analysis of the impedance diagrams revealed the presence of two processes. The cathodic polarization resistances have been measured and the lowest values at 600 °C are 0.28 and 0.30 Ω*cm2 for Pr2NiO4 + δ/Ce0.9Gd0.1O2 − δ and La0.6Sr0.4Fe0.8Co0.2O3 − δ/La0.8Sr0.2Ga0.8Mg0.2O3 − δ, respectively. These results have demonstrated that both systems are suitable for IT-SOFC applications

Quito face à un risque d'origine naturelle : les laves torrentielles

International audienceThe 31st of March 1997 a debris flow seriously affected the quebrada La Comunidad and. Morpho-hydro-climatic studies done after this event showed that extreme rainfall storms was the main factor to explain these phenomenons, it is evident that the morphology of the catchment, and particularly the longitudinal profile, played a fundamental part in the generation of debris flows. These events seem preferentially take place in the small catchments, therefore they can be considered as more dangerous than the big ones for the town suburban zones

Optical properties of low loss (70 dB/km) hypocycloid-core Kagome hollow core photonic crystal fiber for Rb and Cs based optical applications

International audienceWe report on hypocycloid core shaped hollow-core Kagome fiber with a record loss of 70 dB/km at a spectral range of around 750-850 nm, which is compatible with Cs and Rb based applications. The fiber exhibits a single mode operation in a core diameter as large as $40~ \mu{\rm m}$ , and very low sensitivity to bend. We show experimentally that the bending-loss is limited by coupling between the guiding core mode and the modes in the cladding holes

Hollow-Core Photonic Crystal Fiber for High Power Laser Beam Delivery

International audienc