Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Ionic Liquids Confined in Hydrophilic Nanocontacts: Structure and Lubricity in the Presence of Water

We have investigated the influence of ambient humidity on the nanoconfined structure and response to shear of ionic liquids. Three ionic liquids (ILs) were selected, namely, 1-ethyl-3-methyl imidazolium ethylsulfate ([EMIM]­[EtSO₄]), 1-ethyl-3-methyl imidazolium tris­(pentafluoroethyl)­trifluorophosphate ([EMIM]­[FAP]), and 1-hexyl-3-methyl imidazolium tris­(pentafluoroethyl)­trifluorophosphate ([HMIM]­[FAP]), to investigate the influence of hygroscopic and hydrophobic anions, as well as different alkyl chain lengths. We employed an extended surface forces apparatus (eSFA) to ascertain the structure of the confined films, whereas colloidal-probe lateral force microscopy (CPM) was used to measure shear forces in the nanosized contact between mica and a silica sphere. The presence of water, the anion, and the alkyl chain length of the imidazolium cation were found to influence the equilibrium structure of the nanoconfined film, as well as its dynamic properties. Adsorbed water appears to change both the ion-pair orientation and the slip condition for film-thickness transitions, that is, the resistance of the IL layers to being squeezed out from the contact. Three lubrication regimes have been identified: a boundary-film lubrication regime with the lowest friction, an intermediate lubrication regime that is highly dependent on the IL anion, and an isoviscous rigid hydrodynamic lubrication regime (with Newtonian fluid-film behavior). It is shown how IL composition and water both influence speed and load dependence of shear forces at the nanoscale. Understanding the response to shear provides further insight into the properties of nanoconfined IL films

Density profile of water in nanoslit

Confined water is abundant in the narrow pores of soil, clay, rock and biological systems. The water molecules are expected to assume layered structures between the confining surfaces, but details on the ordering behavior are lacking. In this letter we report density profiles of water across a narrow gap (1.7–1.9 nm) between cleaved mica surfaces studied using X-ray reflectivity. The profiles show pronounced electron density modulations within the gap. These indicate a partial hydration of cations (K+) on the mica surfaces and full hydration of desorbed cations within the gap. The average density of the confined water is close to that of bulk water