Topological Properties in Strained Monolayer Antimony Iodide

Two-dimensional(2D)topological insulators present a special phase of matter manifesting unique electronic properties.Till now,many monolayer binary compounds of Sb element,mainly with a honeycomb lattice,have been reported as 2D topological insulators.However,research of the topological insulating properties of the monolayer Sb compounds with square lattice is still lacking.Here,by means of the first-principles calculations,a monolayer SbI with square lattice is proposed to exhibit the tunable topological properties by applying strain.At different levels of the strain,the monolayer SbI shows two different structural phases:buckled square structure and buckled rectangular structure,exhibiting attracting topological properties.We find that in the buckled rectangular phase,when the strain is greater than 3.78%,the system experiences a topological phase transition from a nontrivial topological insulator to a trivial insulator,and the structure at the transition point actually is a Dirac semimetal possessing two type-ⅠDirac points.In addition,the system can achieve the maximum global energy gap of 72.5 meV in the topological insulator phase,implying its promising application at room temperature.This study extends the scope of 2D topological physics and provides a platform for exploring the low-dissipation quantum electronics devices.

Genetically predicted waist circumference and risk of atrial fibrillation

Introduction:Observational studies have revealed an association between waist circumference(WC)and atrial fibrillation(AF).However,it is difficult to infer a causal relationship from observational studies because the observed associations could be confounded by unknown risk factors.Therefore,the causal role of WC in AF is unclear.This study was designed to investigate the causal association between WC and AF using a two-sample Mendelian randomization(MR)analysis.Methods:In our two-sample MR analysis,the genetic variation used as an instrumental variable for MR was acquired from a genome-wide association study(GWAS)of WC(42 single nucleotide polymorphisms with a genetic significance of P<5×10^(-8)).The data of WC(from the Genetic Investigation of ANthropometric Traits consortium,containing 232,101 participants)and the data of AF(from the European Bioinformatics Institute database,containing 55,114 AF cases and 482,295 controls)were used to assess the causal role of WC on AF.Three different approaches(inverse variance weighted[IVW],MR-Egger,and weighted median regression)were used to ensure that our results more reliable.Results:All three MR analyses provided evidence of a positive causal association between high WC and AF.High WC was suggested to increase the risk of AF based on the IVW method(odds ratio[OR]=1.43,95%confidence interval[CI],1.30-1.58,P=2.51×10^(-13)).The results of MR-Egger and weighted median regression exhibited similar trends(MR-Egger OR=1.40[95%CI,1.08-1.81],P=1.61×10^(-2);weighted median OR=1.39[95%CI,1.21-1.61],P=1.62×10^(-6)).MR-Egger intercepts and funnel plots showed no directional pleiotropic effects between high WC and AF.Conclusions:Our findings suggest that greater WC is associated with an increased risk of AF.Taking measures to reduce WC may help prevent the occurrence of AF.

Impact of baseline blood pressure on all-cause mortality in patients with atrial fibrillation:results from a multicenter registry study

Background:The ideal blood pressure(BP)target for patients with atrial fibrillation(AF)is still unclear.The present study aimed to assess the effect of the baseline BP on all-cause mortality in patients with AF.Methods:This registry study included 20 emergency centers across China and consecutively enrolled patients with AF from 2008 to 2011.All participants were followed for 1 year±1 month.The primary endpoint was all-cause mortality.Results:During the follow-up,276(13.9%)all-cause deaths occurred.Kaplan-Meier curves showed that a systolic blood pressure(SBP)110 mmHg or>160 mmHg was associated with a higher risk of all-cause mortality(log-rank test,P=0.014),and a diastolic blood pressure(DBP)<70 mmHg was associated with the highest risk of all-cause mortality(log-rank test,P=0.002).After adjusting for confounders,the multivariable Cox regression model suggested that the risk of all-cause mortality was increased in the group with SBP110 mmHg(hazard ratio[HR],1.963;95%confidence interval[CI],1.306-2.951),and DBP<70 mmHg(HR,1.628;95%CI,1.163-2.281).In the restricted cubic splines,relations between baseline SBP or DBP and all-cause mortality showed J-shaped associations(non-linear P<0.001 and P=0.010,respectively).The risk of all-cause mortality notably increased at a lower baseline SBP and DBP.Conclusions:Having a baseline SBP110 mmHg or DBP<70 mmHg was associated with a significantly higher risk of all-cause mortality in patients with AF.An excessively low BP may not be an optimal target for patients with AF.

符合ABC管理路径对中国急诊心房颤动患者预后的影响

目的探讨符合心房颤动(房颤)更好的管理(atrial fibrillation better care,ABC)管理路径对中国急诊房颤患者预后的影响。方法纳入2008年11月至2011年10月在中国20家医院急诊就诊的房颤患者,并随访12个月。根据患者是否符合ABC管理路径分为2组:符合ABC路径组与不符合ABC路径组。主要临床结局事件为全因死亡,次要临床结局事件为心血管死亡、卒中和大出血事件。应用Cox回归模型分析上述事件的影响因素。结果共纳入2015例房颤患者,年龄(68.5±13.3)岁,其中女1104例(54.8%)。随访12个月,符合ABC路径组(126/2015例,6.3%)患者死亡4例(3.2%,4/126),其中心血管死亡1例(0.8%,1/126);不符合ABC路径组(1889/2015例,93.7%)患者死亡275例(14.6%,275/1889),其中心血管死亡163例(8.6%,163/1889)。两组患者卒中和大出血发生率差异无统计学意义。多因素Cox模型分析显示,与不符合ABC路径组比,符合ABC路径组的全因死亡风险(HR 0.211,95%CI 0.078~0.572,P=0.002)和心血管死亡风险(HR 0.085,95%CI 0.012~0.612,P=0.014)均显著下降。结论在当代真实的中国急诊房颤患者队列中,符合ABC路径的临床综合管理与显著降低全因死亡、心血管死亡风险相关,采用ABC路径的综合管理可以改善房颤患者的预后。

Mechanism of the trivalent lanthanides’persistent luminescence in wide bandgap materials

The trivalent lanthanides have been broadly utilized as emitting centers in persistent luminescence(PersL)materials due to their wide emitting spectral range,which thus attract considerable attention over decades.However,the origin of the trivalent lanthanides’PersL is still an open question,hindering the development of excellent PersL phosphors and their broad applications.Here,the PersL of 12 kinds of the trivalent lanthanides with the exception of La^(3+),Lu^(3+),and Pm^(3+) is reported,and a mechanism of the PersL of the trivalent lanthanides in wide bandgap hosts is proposed.According to the mechanism,the excitons in wide bandgap materials transfer their recombination energy to the trivalent lanthanides that bind the excitons,followed by the generation of PersL.During the PersL process,the trivalent lanthanides as isoelectronic traps bind excitons,and the binding ability is not only related to the inherent arrangement of the 4f electrons of the trivalent lanthanides,but also to the extrinsic ligand field including anion coordination and cation substitution.Our work is believed to be a guidance for designing high-performance PersL phosphors.

Temperature and structural responses of a single-section utility tunnel throughout fire exposure

In this study,fire tests of four single-section scaled-down utility tunnels were conducted.By analyzing temperature and structural responses of the utility tunnel throughout the fire exposure,the effects on the fire behavior of two different construction methods,cast-in-situ and prefabricated,and of two different materials,ordinary concrete and full lightweight concrete,were explored.The results of the study showed that the shear failure of the cast-in-situ utility tunnel occurred at the end of the top or bottom plate,and the failure of the prefabricated utility tunnel occurred at the junction of the prefabricated member and post-cast concrete.As the temperature increased,the temperature gradient along the thickness direction of the tunnel became apparent.The maximum temperature difference between the inner and outer wall surfaces was 531.7°C.The highest temperature occurred in the cooling stage after stopping the heating,which provided a reference for the fire protection design and rescue of the utility tunnel.The displacement of the top plate of the prefabricated utility tunnel was 16.8 mm,which was 41.8%larger than that of the cast-in-situ utility tunnel.The bearing capacities of the ordinary concrete utility tunnel and full lightweight concrete utility tunnel after the fire loss were 27%and 16.8%,respectively.The full lightweight concrete utility tunnel exhibited good ductility and fire resistance and high collapse resistance.