Aortic stenosis(AS)is a progressive heart valve disease occurring predominantly in older patients.According to a survey in a western country,the prevalence of AS is nearly 6.4%in patients over 75 years old(Carabello and Paulus,2009).Transcatheter aortic valve replacement(TAVR)is an alternative method for AS patients.Previous studies have described how up to 66%of TAVR patients have concomitant baseline kidney dysfunction(Ferro et al.,2015;Gargiulo et al.,2015).The majority of patients can benefit from the TAVR procedure with the recovery of kidney function. 相似文献
The purpose of this study was to explore Chinese university professors’ decisions about ethical issues in classroom assessment. A survey with fifteen scenarios that describe professors’ thoughts about ethics in assessment practices was administrated to 555 professors from 143 colleges and universities in 29 provinces in China. The results of the quantitative analysis indicated that professors’ interest in professional development related to classroom assessment, and their dispositions were significantly associated with their agreement with experts in the field of classroom assessment. Professors’ gender, highest degree, professional rank, and years of teaching experience did not significantly predict their agreement. The qualitative analysis revealed that maintaining fair assessment vs being caring to students and asserting professors’ rights vs abiding by university policy were the crucial aspects for professors to consider in classroom assessment. Findings of the study could help educators identify ethical issues in assessment, develop guidelines to ensure fair assessment, and incorporate differentiated strategies in professional development workshops in higher education.
Shear failure in panel zones and plastic hinges in steel beams are the two major failure modes of connections between concrete-filled steel tubular(CFST) columns and steel beams. To investigate the behavior of this type of connection in both modes,two through-diaphragm connections were tested under cyclic and monotonic loadings and the load-carrying capacity,ductility,and strength of degradation of connections were discussed. Using ABAQUS software,we developed nonlinear finite-element models(FEMs) to simulate the load-carrying capacity and failure modes of the connections under monotonic loading. The finite-element(FE) analysis and test results showed reasonable agreement for the through-diaphragm connections,which confirms the accuracy of FEMs in predicting the load-carrying capacity and failure modes of connections. Based on the validated FEM,a parametric study was then conducted to investigate the infl uence of the thicknesses of the tube and diaphragm on the load-carrying capacity and failure modes of these connections. The results indicate that the strength,stiff ness,and load-carrying capacity are infl uenced less by the thickness of the diaphragm,and more by the thickness of the steel tube. According to the FE analysis results,it can be found that the critical condition between the two failure modes is determined by the shear resistance and bending resistance. 相似文献