Serious games en bibliothèque (Les)

Dossier d’accompagnement réalisé par des élèves conservateurs, pour la journée Serious game qu\u27ils ont organisée à l\u27enssib le 24 octobre 2012 dans le cadre de l\u27U.E. "Comprendre le numérique

Feasibility of mechanical extrusion to coat nanoparticles with extracellular vesicle membranes

Biomimetic functionalization to confer stealth and targeting properties to nanoparticles is a field of intense study. Extracellular vesicles (EV), sub-micron delivery vehicles for intercellular communication, have unique characteristics for drug delivery. We investigated the top-down functionalization of gold nanoparticles with extracellular vesicle membranes, including both lipids and associated membrane proteins, through mechanical extrusion. EV surface-exposed membrane proteins were confirmed to help avoid unwanted elimination by macrophages, while improving autologous uptake. EV membrane morphology, protein composition and orientation were found to be unaffected by mechanical extrusion. We implemented complementary EV characterization methods, including transmission- and immune-electron microscopy, and nanoparticle tracking analysis, to verify membrane coating, size and zeta potential of the EV membrane-cloaked nanoparticles. While successful EV membrane coating of the gold nanoparticles resulted in lower macrophage uptake, low yield was found to be a significant downside of the extrusion approach. Our data incentivize more research to leverage EV membrane biomimicking as a unique drug delivery approach in the near future

Admission criteria and management of critical care patients in a pandemic context: position of the Ethics Commission of the French Intensive Care Society, update of April 2021.

Intensive care unit professionals have experience in critical care and its proportionality, collegial decision-making, withholding or withdrawal of treatment deemed futile, and communication with patients' relatives. These elements rely on ethical values from which we must not deviate in a pandemic situation. The recommendations made by the Ethics Commission of the French Intensive Care Society reflect an approach of responsibility and solidarity towards our citizens regarding the potential impact of a pandemic on critical care resources in France, with the fundamental requirement of respect for human dignity and equal access to health care for all

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

An analysis of the slow compression breakage of coal using microfocus X-ray computed tomography

The degradation of coal and the production of coal fines during handling and transport is a serious problem in processes that depend on closely sized large particles. To minimize the production of fines, a fundamental understanding of coal breakage is required, so, to clarify the complex nature of coal breakage, a series of experiments was conducted to determine the influence of the internal physical coal structures on compression breakage characteristics. The structures investigated are the cleat and layered structure of coal and the mineral inclusions. Samples of uniform size and shape were prepared from a large block of South African Waterberg coal. The samples were analyzed nondestructively using microfocus x-ray computed tomography then wrapped in cling film and mechanically compressed while the pressure applied was measured. The virtual three-dimensional volume tomograms of the initial sample and the progeny were compared and the changes qualitatively analyzed. Conclusions were drawn as to where the fatal cracks initialized and how the cracks propagated. Particle-size distributions were done to quantify the extent of breakage versus the breakage strength of the sample. It was found that, of all the internal structures, the inherent crack distribution has the biggest influence on breakage and breakage patterns of coalThis work was presented at the 27th International Coal Preparation Congress (ICPC) in Istanbul, Turke

Etude et miniaturisation d'un analyseur basse fréquence destiné à la correction de l'effet Doppler à bord d'une sonde en mouvement rapide par rapport au milieu étudié (application à la mission "Solar Probe")

La mission "Solar Probe" (NASA) est une mission d'exploration de la couronne solaire qui combinera de l'imagerie à des mesures in situ de façon à étudier des phénomènes physiques tels que l'accélération du vent solaire et le chauffage de la couronne. Pour cela, les expériences embarquées doivent permettre de caractériser les ondes qui se propagent dans le plasma. Or, dans le cas des ondes basses fréquences, la vitesse de la sonde par rapport au plasma entraînera un décalage Doppler k. V important qu'il est indispensable d'évaluer pour caractériser correctement les ondes. Nous avons montré que le calcul de k. V et la correction des données, à partir de la mesure B et J dans le repère de la sonde et de l'utilisation de l'équation d'Ampère dans la limite basse fréquence, est possible. La validité de cette méthode a été démontrée, par des simulations, pour différentes combinaisons d'ondes planes. cependant, cette méthode n'est pas toujours utilisable, en particulier dans le cas d'ondes accompagnant la sonde (Vg [environ]Vsonde). Le faible taux de télémesure accordé rend intéressante l'utilisation d'un analyseur embarquée pour réaliser la correction Doppler. La faisabilité de cet analyseur a été étudiée au cours de la thèse. Cette étude comporte deux grands axes : la conception d'une maquette sur table et la miniaturisation d'un élément de la chaîne d'acquisition. L'utilisation du microprocesseur ADSP21060L a permis de réaliser un analyseur faible consommation (environ 1W) compatible avec les contraintes de la mission. Ce processeur n'étant pas qualifié pour les applications spatiales nous avons réalisé une pré-étude de tenue aux radiations dont les résultats sont favorables. La réalisation en technologie 3D d'un système de trois préamplificateurs et leur alimentation, associé à un tri-axes d'antennes magnétiques, a permis de réduire de 30/ la masse et le volume par rapport à la réalisation hybride utilisée précédemment sans dégradation de la sensibilté.VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF

Candida bloodstream infection under veno-arterial ECMO therapy

SCOPUS: le.jinfo:eu-repo/semantics/publishe

Depletion of soluble cytokines unlocks the immunomodulatory bioactivity of extracellular vesicles

Abstract Despite an enormous interest in understanding the bioactivity of extracellular vesicles (EV) in physiology and disease for the development of therapeutic applications, the impact of EV preparation methods remains minimally explored. In this study, we implemented density gradient ultracentrifugation combined with size‐exclusion chromatography (DG‐SEC), differential ultracentrifugation (dUC) and/or stand‐alone SEC (sSEC) to fractionate media conditioned by different cancer cells and/or cancer‐associated fibroblasts (CAF). EV‐enriched but protein‐depleted versus EV‐depleted but protein‐enriched DG‐SEC fractions, and EV‐containing dUC and sSEC preparations were quality controlled for particle number, protein concentration, selected protein composition and ultrastructure, characterized for their cytokine content, and dose‐dependently evaluated for monocyte‐derived dendritic cell (MoDC) maturation by measuring surface marker expression and/or cytokine secretion. EV preparations obtained by DG‐SEC from media conditioned by different cancer cell lines or CAF, were depleted from soluble immune suppressive cytokines such as VEGF‐A and MCP‐1 and potently stimulated MoDC maturation. In contrast, EV‐containing dUC or sSEC preparations were not depleted from these soluble cytokines and were unable to mature MoDC. Subsequent processing of dUC EV preparations by SEC dose‐dependently restored the immunomodulatory bioactivity. Overall, our results demonstrate that method‐dependent off‐target enrichment of soluble cytokines has implications for the study of EV immunomodulatory bioactivity and warrants careful consideration