Quantum confinement effect and reduced dielectric screening in two-dimensional(2D)dramatically enhance theelectron-hole interactions.In this work,we use many-body perturbation theory and Bethe-Salpeter equation(BSE)to...Quantum confinement effect and reduced dielectric screening in two-dimensional(2D)dramatically enhance theelectron-hole interactions.In this work,we use many-body perturbation theory and Bethe-Salpeter equation(BSE)toinvestigate the electronic and excitonic optical properties of monolayer SnP_(2)S_(6).Our findings reveal that the excitoniceffect dominates the optical absorption spectra in the visible light range,and the lowest-energy exciton X0 in monolayerSnP_(2)S_(6)is optically bright with the binding energy of 0.87 eV and the radiative lifetime of~10^(-11)s,which is highly advantageousto the photo-luminescence.Most importantly,the absence of optically forbidden states below the bright statesX0 would give rise to a high quantum efficiency of 2D SnP_(2)S_(6).We also find that applied biaxial strain can further shortenthe radiative lifetime of the bright states.These results imply that 2D SnP_(2)S_(6)is a promising candidate for the optoelectronicdevices.展开更多
目的探讨心力衰竭患者院内治疗评分(organized program to initiate lifesaving treatment in hospitalizedpatients with heart failure,OPTIMIZE-HF)对于心力衰竭患者住院期间发生造影剂肾病(contrast inducednephrology,CIN)的预测价...目的探讨心力衰竭患者院内治疗评分(organized program to initiate lifesaving treatment in hospitalizedpatients with heart failure,OPTIMIZE-HF)对于心力衰竭患者住院期间发生造影剂肾病(contrast inducednephrology,CIN)的预测价值,研究该评分与心力衰竭患者院内主要心血管事件(major adverse cardiovascularevent,MACE)和远期预后的关系。方法 2010年1月起至2012年10月,广东省人民医院心内科连续纳入1 594例行冠状动脉造影检查或经皮冠状动脉介入(PCI)治疗且纽约心脏协会心功能分级≥Ⅱ级的患者。监测术前、术后患者血清肌酐(serum creatine,SCr)浓度,CIN定义为SCr浓度较基线绝对增高≥5 mg/L。每例患者计算OPTIMIZE-HF评分,并利用受试者工作特征(receiver operator characteristic,ROC)曲线和多因素Logistics回归分析探讨评分对CIN及院内MACE发生的预测价值。利用log-rank回归及COX回归分析患者的远期预后。结果 1 594例患者中,OPTIMIZE-HF评分最低0分,最高57分,四分位点分别是22分,26分,30分。根据OPTIMIZE-HF评分结果,将1 594例患者分为4组:Q1组406例,OPTIMIZE-HF评分0~22分;Q2组420例,OPTIMIZE-HF评分23~26分;Q3组398例,OPTIMIZE-HF评分27~30分;Q4组370例,OPTIMIZE-HF评分31~57分。共发生CIN 45例(2.82%),CIN发生率随着评分升高而增高,4组CIN发生率比较,差异有统计学意义(P<0.001)。发生CIN与OPTIMIZE-HF评分较高患者的院内MACE发生率明显高于未发生CIN及评分较低患者,差异有统计学意义(P<0.001)。OPTIMIZE-HF评分对于预测院内MACE的ROC曲线下面积达到0.742。多因素Logistics回归分析显示OPTIMIZE-HF是预测CIN发生的独立预测因子(P=0.006)。结论OPTIMIZE-HF评分能够预测心力衰竭患者CIN的发生,且可以很好地预测院内MACE的发生。CIN发生及OPTIMIZE-HF评分过高均提示心力衰竭患者PCI治疗后的远期预后不良。展开更多
基金support by the National Natural Science Foundation of China(Grant No.12064032).
文摘Quantum confinement effect and reduced dielectric screening in two-dimensional(2D)dramatically enhance theelectron-hole interactions.In this work,we use many-body perturbation theory and Bethe-Salpeter equation(BSE)toinvestigate the electronic and excitonic optical properties of monolayer SnP_(2)S_(6).Our findings reveal that the excitoniceffect dominates the optical absorption spectra in the visible light range,and the lowest-energy exciton X0 in monolayerSnP_(2)S_(6)is optically bright with the binding energy of 0.87 eV and the radiative lifetime of~10^(-11)s,which is highly advantageousto the photo-luminescence.Most importantly,the absence of optically forbidden states below the bright statesX0 would give rise to a high quantum efficiency of 2D SnP_(2)S_(6).We also find that applied biaxial strain can further shortenthe radiative lifetime of the bright states.These results imply that 2D SnP_(2)S_(6)is a promising candidate for the optoelectronicdevices.