Coulomb explosion and binary encounter processes in collisions between slow ions and small molecules of biological interest

International audienceIn this work we study the ion impact induced fragmentation of small molecules, which are relevant for radiation damage studies in biological tissues. We present double differential ion emission yields for collisions of N6+ ions with water and methane molecules at 15 and 30 keV impact energies. The angular distribution of the fragment ions shows post-collision and nucleus-nucleus binary collision effects. In the multiple capture energy range, a strong interplay is indicated between the Coulomb explosion and the binary collision mechanisms. In the energy region, where triple capture is dominant, an unexpected angular distribution was found for water fragments, which may be attributed to orientation sensitivity of some of the capture channels. Such processes are relevant for astrophysics and radiation therapy

Anisotropic ion emission in the fragmentation of small molecules by highly charged ion impact

International audienceIn this work, we present double differential ion emission yields measured by the method of fragment ion spectroscopy for collisions of N6+ and O7+ ions with water and methane molecules at ~30 keV impact energies. The angular distribution of the fragment ions shows expected post-collision and nucleus-nucleus binary collision effects with the indication of an interplay between Coulomb explosion and binary collision mechanisms. We have found significant differences in the fragmentation patterns of methane for the two projectiles, which may be a signature of strong, resonant capture channels. For triple capture, an unexpected angular distribution has been found for water, which may be attributed to orientation sensitivity of some of the capture channels. Such processes can be highly important for radiation therapy and astrophysics

Dissociative ionization of the H2O molecule bombarded by swift singly charged and slow highly charged ions

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Vasculitis associated with myelodysplastic syndrome and chronic myelomonocytic leukemia: French multicenter case-control study

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Increased risk of severe COVID-19 in hospitalized patients with SARS-CoV-2 Alpha variant infection: a multicentre matched cohort study

International audienceBackground: The impact of the variant of concern (VOC) Alpha on the severity of COVID-19 has been debated. We report our analysis in France.Methods: We conducted an exposed/unexposed cohort study with retrospective data collection, comparing patients infected by VOC Alpha to contemporaneous patients infected by historical lineages. Participants were matched on age (± 2.5 years), sex and region of hospitalization. The primary endpoint was the proportion of hospitalized participants with severe COVID-19, defined as a WHO-scale > 5 or by the need of a non-rebreather mask, occurring up to day 29 after admission. We used a logistic regression model stratified on each matched pair and accounting for factors known to be associated with the severity of the disease.Results: We included 650 pairs of patients hospitalized between Jan 1, 2021, and Feb 28, 2021, in 47 hospitals. Median age was 70 years and 61.3% of participants were male. The proportion of participants with comorbidities was high in both groups (85.0% vs 90%, p = 0.004). Infection by VOC Alpha was associated with a higher odds of severe COVID-19 (41.7% vs 38.5%-aOR = 1.33 95% CI [1.03-1.72]).Conclusion: Infection by the VOC Alpha was associated with a higher odds of severe COVID-19