The value of left atrial strain and strain rate in predicting left atrial appendage stasis in patients with nonvalvular atrial fibrillation

  Background: This study aimed to investigate the value of left atrial (LA) strain and strain rate (S/SR) by transthoracic echocardiography (TTE) in predicting left atrial appendage (LAA) stasis, in order to find a way for LAA stasis screening which is easily performed in patients with nonvalvular atrial fibrillation (NVAF). Methods: One hundred and thirty NVAF patients prepared for AF ablation were enrolled. TTE and transesophageal echocardiography (TEE) were performed in all patients. LA S/SR in each phase was analyzed off-line. LAA blood flow state and LAA function were assessed by using TEE. Results: LA S/SRs during atrial reservoir phase (LA Sres/SRres) were significantly negatively cor­related with LAA spontaneous echo contrast (SEC) grade (r = −0.567 and −0.520, respectively; all p < 0.01), and positively correlated with LAA emptying fraction (r = 0.602 and 0.619, respectively; all p < 0.01) and with LAA peak emptying flow velocity (r = 0.623 and 0.642, respectively; all p < 0.01). The multivariate logistic regression analysis showed LA Sres to be the strongest independent predictor of LAA stasis, followed by LA volume index. LA Sres < 13% was recommended to predict LAA stasis with sensitivity of 90% and specificity of 74%. Conclusions: LA Sres by TTE can noninvasively predict LAA stasis and may be used as a screening tool to assist in the detection of LAA stasis in patients with NVAF. (Cardiol J 2018; 25, 1: 87–96

Deciphering neo-sex and B chromosome evolution by the draft genome of Drosophila albomicans

<p>Abstract</p> <p>Background</p> <p><it>Drosophila albomicans </it>is a unique model organism for studying both sex chromosome and B chromosome evolution. A pair of its autosomes comprising roughly 40% of the whole genome has fused to the ancient X and Y chromosomes only about 0.12 million years ago, thereby creating the youngest and most gene-rich neo-sex system reported to date. This species also possesses recently derived B chromosomes that show non-Mendelian inheritance and significantly influence fertility.</p> <p>Methods</p> <p>We sequenced male flies with B chromosomes at 124.5-fold genome coverage using next-generation sequencing. To characterize neo-Y specific changes and B chromosome sequences, we also sequenced inbred female flies derived from the same strain but without B's at 28.5-fold.</p> <p>Results</p> <p>We assembled a female genome and placed 53% of the sequence and 85% of the annotated proteins into specific chromosomes, by comparison with the 12 <it>Drosophila genomes</it>. Despite its very recent origin, the non-recombining neo-Y chromosome shows various signs of degeneration, including a significant enrichment of non-functional genes compared to the neo-X, and an excess of tandem duplications relative to other chromosomes. We also characterized a B-chromosome linked scaffold that contains an actively transcribed unit and shows sequence similarity to the subcentromeric regions of both the ancient X and the neo-X chromosome.</p> <p>Conclusions</p> <p>Our results provide novel insights into the very early stages of sex chromosome evolution and B chromosome origination, and suggest an unprecedented connection between the births of these two systems in <it>D. albomicans</it>.</p

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

The global response: How cities and provinces around the globe tackled Covid-19 outbreaks in 2021

Background: Tackling the spread of COVID-19 remains a crucial part of ending the pandemic. Its highly contagious nature and constant evolution coupled with a relative lack of immunity make the virus difficult to control. For this, various strategies have been proposed and adopted including limiting contact, social isolation, vaccination, contact tracing, etc. However, given the heterogeneity in the enforcement of these strategies and constant fluctuations in the strictness levels of these strategies, it becomes challenging to assess the true impact of these strategies in controlling the spread of COVID-19.Methods: In the present study, we evaluated various transmission control measures that were imposed in 10 global urban cities and provinces in 2021 Bangkok, Gauteng, Ho Chi Minh City, Jakarta, London, Manila City, New Delhi, New York City, Singapore, and Tokyo.Findings: Based on our analysis, we herein propose the population-level Swiss cheese model for the failures and pit-falls in various strategies that each of these cities and provinces had. Furthermore, whilst all the evaluated cities and provinces took a different personalized approach to managing the pandemic, what remained common was dynamic enforcement and monitoring of breaches of each barrier of protection. The measures taken to reinforce the barriers were adjusted continuously based on the evolving epidemiological situation.Interpretation: How an individual city or province handled the pandemic profoundly affected and determined how the entire country handled the pandemic since the chain of transmission needs to be broken at the very grassroot level to achieve nationwide control

The crystal structure of (3S,12R,20R,24R)-3,12-diacetyl-20,24-epoxy-dammarane-3,12,25–triol–ethyl acetate (4/1), C34H56O6⋅ 0.25(C4H8O2)

C34H56O6⋅0.25(C4H8O2), orthorhombic, P212121 (no. 19), a = 8.17152(14) Å, b = 17.6728(3) Å, c = 23.1916(5) Å, V = 3349.18(11) Å3, Z = 4, Rgt(F) = 0.0416, wRref(F2) = 0.1143, T = 293 K