Helium precipitation study in UO2 by Transmission Electron Microscopy

International audienc

Predictors of Visceral Leishmaniasis Relapse in HIV-Infected Patients: A Systematic Review

Visceral leishmaniasis (VL) is the most serious form of an insect-transmitted parasitic disease prevalent in 70 countries. The disease is caused by species of the L. donovani complex found in different geographical regions. These parasites have substantially different clinical, drug susceptibility and epidemiological characteristics. According to data from the World Health Organization, the areas where HIV-Leishmania co-infection is distributed are extensive. HIV infection increases the risk of developing VL, reduces the likelihood of a therapeutic response, and greatly increases the probability of relapse. A better understanding of the factors promoting relapses is essential; therefore we performed a systematic review of articles involving all articles assessing the predictors of VL relapse in HIV-infected individuals older than 14 years of age. Out of 178 relevant articles, 18 met the inclusion criteria and in total, data from 1017 patients were analyzed. We identified previous episodes of VL relapse, CD4+ lymphocyte count fewer than 100 cells/mL at VL diagnosis, and the absence of an increase in CD4+ counts at follow-up as major factors associated with VL relapse. Knowledge of relapse predictors can help to identify patients with different degrees of risk, facilitate and direct prophylaxis choices, and aid in patient counseling

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Direct observation of the reversible changes of the morphology of Pt nanoparticles under gas environment

International audienc

Helium precipitation study in UO2_2 by Transmission Electron Microscopy

International audienc

quantification by epma of glass for nuclear application

International audienceThe confinement of high-level radioactive waste from spent nuclear fuel reprocessing is a key issue in the nuclear fuel cycle. In France, waste storage concept is based on four containment barriers including respectively glass matrix for radioactive waste immobilization, a primary stainless steel canister, a thick carbon steel overpack and finally a host rock. Numerous researches are carried out on nuclear glass to improve the properties of the confinement material. Depending on glass composition and process parameters crystals can appear in the matrix (Fig. 1). The characterization of these phases (range of micrometer size) and of the glass surrounding them is of great importance for a proper understanding of the glass properties and its long term performance. The composition of these phases can be characterized by means of electron microprobe (CAMECA SX 100) with a standard resolution electron beam. In order to improve the quantification of such small dimension inclusions, the use of FEG-EPMA CAMECA SX FiveFE has been tested to determine their chemical composition which is well adapted to micrometer range analysis. The improved analytical resolution obtained with the FEG-EPMA made it possible to optimize the analysis of the micro particles, and to determine their chemical composition. The nature of the crystal phases was confirmed by EBSD electronic diffraction analysis coupled with SEM and approved the crystalline phases of apatite and cerianite measured by EPMA. To study in a more precise way the glass matrix near crystals, thin lamellas were prepared by ionic cut by FIB (Fig. 2). A microstructural analysis by TEM was performed to characterize the glass matrix and the inclusions and the chemical composition was settled by EDS quantification. This thin lamella were analyzed by EPMA in transmission with the microprobe CAMECA SX 100 to get a more complete analysis of elements, including especially some light elements such as Boron. The results of TEM EDS and EPMA analyses in transmission are self-consistent and confirm a peculiar enrichment in Zr of the glass matrix near crystals

New Analytical Developments for Uranium Based Powder

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