Andrew J. Martin

TL;DR: In this article , the authors evaluated the long-term safety and efficacy of a novel cryoballoon ablation catheter in treating paroxysmal atrial fibrillation (PAF).

Abstract: Silicification has important implications for the enrichment and distribution of Au within oceanic crust; it leads to significant enrichment of Au in areas distal to VMS deposits providing targets for mineral exploration. Previous studies by Prichard and Maliotis (1998) revealed an enrichment of Au in silicified umbers. Umbers are hydrothermal muds of exhalative origin found on the seafloor. Pre silicification, umbers contained approximately 5 ppb Au whereas post silicification, Au concentrations are enriched to ppm levels. The behaviour and enrichment of other critical elements such as Se and Te that can have affinities for Au in hydrothermal systems have not previously been studied in the silicifying ‘off axis’ system. On a fundamental level, the distribution, tectonic environment and metal potential of these late-stage silicifying events remains poorly understood. To address this issue, the silicified system at Alpen Rose in the eastern Troodos ophiolite of Cyprus has been studied. The Alpen Rose deposit is located 1.5 km west of the village of Mathiatis. It is a ridge comprised of multiple mineralised lava flows, approximately 100 m high and striking NW–SE. Lava flows are approximately 60 m wide, dipping steeply towards the NE and contain minor disseminated pyrite and chalcopyrite. To the southwest the ridge is bound by a breccia unit and oblique normal fault. Striking approximately parallel to the ridge are a series of massive brecciated quartz veins. Structurally the ridge is heavily segmented by a series of N–S/NE–SW dilatational faults. New geochemical analyses coupled with detailed field observations are presented in this study. These show multiple phases of silicification and ppm-level Au, Sb, As and Ag mineralisation. The study also highlights the strong correlation between Au and Te in the ‘off axis’ hydrothermal system and significant Te enrichment of up to 0.8 ppm. Although Te does exhibit a strong correlation with Au, several samples which contain appreciable Te contain minor Au (<50 ppb). This suggests the mineral deportment of Te is not exclusively within Au–Ag tellurides; other phases may host appreciable Te. Structurally the ridge occurs at a hypothetical ridge boundary (an area between two spreading centres). In these areas, dilatational faulting may have acted as a fluid conduit for late-stage silicification. This study highlights the significance of late-stage hydrothermal fluids in the enrichment of both precious metals and Te in oceanic crust.

TL;DR: This study reveals sex-dimorphic immune imprints and in vivo functional impacts of mild COVID-19 in humans, suggesting that prior CO VID-19 could change future responses to vaccination and in turn, vaccines could help reset the immune system after COVID -19, both in an antigen-agnostic manner.