59 research outputs found

    Associations Between Helminth Infections, Plasmodium falciparum Parasite Carriage and Antibody Responses to Sexual and Asexual Stage Malarial Antigens.

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    Infections with helminths and Plasmodium spp. overlap in their geographical distribution. It has been postulated that helminth infections may influence malarial transmission by altering Plasmodium falciparum gametocytogenesis. This cross-sectional study assessed the effect of helminth infections on P. falciparum gametocyte carriage and on humoral immune responses to sexual stage antigens in Gabon. Schistosoma haematobium and filarial infections as well as P. falciparum asexual forms and gametocyte carriage were determined. The antibody responses measured were to sexual (Pfs230, Pfs48/45) and asexual P. falciparum antigens (AMA1, MSP1, and GLURP). A total of 287 subjects were included. The prevalence of microscopically detectable P. falciparum asexual parasites was higher in S. haematobium-infected subjects in comparison to their uninfected counterparts (47% versus 26%, P = 0.003), but this was not different when filarial infections were considered. Plasmodium falciparum gametocyte carriage was similar between Schistosoma- or filaria-infected and uninfected subjects. We observed a significant decrease of Pfs48/45 immunoglobulin G titer in S. haematobium-infected subjects (P = 0.037), whereas no difference was seen for Pfs230 antibody titer, nor for antibodies to AMA1, MSP1, or GLURP. Our findings suggest an effect of S. haematobium on antibody responses to some P. falciparum gametocyte antigens that may have consequences for transmission-blocking immunity

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

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    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/)

    La répression du dopage dans le sport

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    International audience(commentaire de la loi n° 89-432 du 28 juin 1989 relative à la prévention et à la répression de l'usage des produits dopants à l'occasion des compétitions et manifestations sportives

    Revisiting micro hot-embossing with moulds in non-conventional materials

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    International audienceManufacturing moulds in non-metallic tooling materials using non conventional structuring techniques is explored for rapid and/or alternative tooling for hot embossing of polymers. Some challenges and advantages of producing embossing tools by deep reactive ion etching (DRIE) in silicon and/or replica-casting in poly(dimethylsiloxane) (PDMS) and utilizing them in the replication process are highlighted

    DRIE of non-conventional materials: first results

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    International audienceHigh speed directional etching of non conventional materials is still insufficiently developed for producing high aspect ratio microstructures. Compared to deep silicon etching, the plasma etching of these materials has suffered from limitations in achievable depth, aspect ratio, verticality and smoothness of surfaces. Inductively coupled plasma (ICP) reactive ion etching (RIE) of quartz crystal, lithium niobate and glass was conducted using fluorine and fluorocarbon based plasma-chemical etching processes. Optimization of etched depth, verticality of the walls, etch rate, etch selectivity towards the etch mask, and surface smoothness was investigated and compared to results of the literature. Deep etching with nearly vertical walls was successfully demonstrated for all three materials

    Etude d’un écoulement cyclique à bouchon lors de la condensation dans un microcanal

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    Des études simultanées de visualisation et de mesures expérimentales ont été menées afin d’étudier différents régimes d’écoulement de condensation de la vapeur d’eau dans des microcannaux gravés sur silicium. Dans ce papier, on présente les résultats d’une étude d’analyse d’un écoulement à bouchon visualisé lors de la condensation de la vapeur d’eau dans un microcanal. Le microcanal est de section rectangulaire et gravé dans un wafer en silicium. On présente la fréquence de production des bulles durant le cycle de l’écoulement. La vitesse et la taille de deux bulles présentes en amont et en aval d’un bouchon liquide sont analysées

    Development of miniaturized pH biosensors based on electrosynthesized polymer films

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    International audienceA new type of pH biosensor was developed for biological applications. This biosensor was fabricated using silicon microsystem technology and consists in two platinum microelectrodes. The first microelectrode was coated by an electrosynthesized polymer and acted as the pH sensitive electrode when the second one was coated by a silver layer and was used as the reference electrode. Then, this potentiometric pH miniaturized biosensor based on electrosynthesized polypyrrole or electrosynthesized linear polyethylenimine films was tested. The potentiometric responses appeared reversible and linear to pH changes in the range from pH 4 to 9. More, the responses were fast (less than 1 min for all sensors), they were stable in time since PPy/PEI films were stable during more than 30 days, and no interference was observed. The influence of the polymer thickness was also studied
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