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/)

Co-Digestion of Extended Aeration Sewage Sludge with Whey, Grease and Septage: Experimental and Modeling Determination

International audienceThe potential of co-digestion mixing thickened secondary sludge (TS) from extended aeration wastewater treatment plant and locally available substrates (whey, grease and septage) has been studied in this work, using three steps. The first step was a batch test to determine the biological methane potential (BMP) of different mixtures of the three co-substrates with TS. The second step was carried out with lab-scale reactors (20 L), simulating anaerobic continuous stirred tank reactors, fed by three mixtures of co-substrates that were determined according to the previous step results. Modeling was applied in the third step, using ADM1 as a mechanistic model to help understand the co-digestion process. According to the BMP step, septage used as a co-substrate has a negative effect on performance, and the addition of 10–30% grease or whey would lead to a gain of around 60–70% in the production of methane. The results from the reactor tests did not validate the positive effects observed with the BMP assay but confirmed good biodegradation efficiency (> 85%). The main purpose of co-digestion in this scenario is to recover energy from waste and effluents that would require even more energy for their treatment. The protein and lipid percentages of particulate biodegradable COD are important variables for digester stability and methane production, as predicted by modeling. The results of simulations with the ADM1 model, adapted to co-digestion, confirmed that this model is a powerful tool to optimize the process of biogas production

Electrostatic precipitator for fine and ultrafine particle removal from indoor air environments

International audienc

Indoor Air Quality Campaign in an Occupied Low-Energy House with a High Level of Spatial and Temporal Discretization

International audienceBackground and gaps. The topic of indoor air quality (IAQ) in low-energy buildings has received increasing interest over the past few years. Often based on two measurement points and on passive measurements over one week, IAQ studies are struggling to allow the calculation of pollutants exposure. Objectives. We would like to improve the evaluation of the health impacts, through measurements able to estimate the exposure of the occupants. Methodology. This article presents detailed IAQ measurements taken in an energy-efficient occupied house in France. Two campaigns were conducted in winter and spring. Total volatile organic compounds (TVOC), formaldehyde, the particle numbers and PM2.5, carbon dioxide (CO2), relative humidity (RH), temperature (T), ventilation airflows, and weather conditions were dynamically measured in several points. Laboratory and low-cost devices were used, and an inter-comparison was carried out for them. A survey was conducted to record all the daily activities of the inhabitants. IAQ performance indicators based on the different pollutants were calculated. Results. PM2.5 cumulative exposure did not exceed the threshold available in the literature. Formaldehyde concentrations were high, in the kitchen, where the average concentrations exceeded the threshold. However, the formaldehyde cumulative exposure of the occupants did not exceed the threshold. TVOC concentrations were found to reach the threshold. With these measurements performed with high spatial and temporal discretization, we showed that such detailed data allow for a better-quality health impacts assessment and for a better understanding of the transport of pollutants between rooms

Etude de l'ozonation de carbones activés en grains et tissus modifiés par des traitements d’oxydation

National audienc

Développement d’un procédé pour l’épuration de l’air intérieur par couplage de la décharge couronne et de l’adsorption

International audienc

Catalytic decomposition performance for O3 and NO2 in humid indoor air on a MnO /Al2O3 catalyst modified by a cost-effective chemical grafting method

International audienc

Non-Thermal Plasma for indoor air treatment: Toluene degradation in a corona discharge at ppbv levels

International audienc

Comparative experiments on a new CaCl2-based composite material and zeolite 13X inside a thermochemical heat storage reactor

Thermal energy storage includes sensible, latent and thermochemical heat storage. The latter is particularly interesting because the heat is stored as a chemical potential, which reduces heat loss in long-term applications. The viability of thermochemical storage systems strongly depends on the energy density of the storage material. The development of high energy density materials is thus essential to achieve compact systems suitable for a wide range of applications. A new sol-gel composite material is investigated here: it is composed of CaCl2 dispersed within a matrix of silica and PEG-600 polymer. Composite materials containing CaCl2 have the highest storage capacities and seem to be the most promising candidates. The aim is to develop a composite that is both efficient and stable. The suitability of the material depends on the ability of the PEG to stabilise calcium chloride and prevent its deliquescence and leakage. The experimental results are compared to those obtained using zeolite 13X, which is a reference adsorbent material

Suitability of Thermal Swing Adsorption for the Treatment of Siloxanes and Toluene in Biogas: An Experimental Study

International audienc