目的:探讨微纤维相关蛋白4(microfibrillar-associated protein 4,MFAP4)与房颤射频消融术后复发及临床结果的相关性。方法:选取2018年12月2020年1月入院均进行了射频消融术治疗的房颤患者101例,术后平均随访(11.91±0.38)个月,根...目的:探讨微纤维相关蛋白4(microfibrillar-associated protein 4,MFAP4)与房颤射频消融术后复发及临床结果的相关性。方法:选取2018年12月2020年1月入院均进行了射频消融术治疗的房颤患者101例,术后平均随访(11.91±0.38)个月,根据是否复发分为复发组与未复发组,比较两组MFAP4、转化生长因子β1(transforming growth factor-β1,TGF-β1)水平、心脏超声指标、体重指数(BMI)、主要的心脑血管事件等情况,分析房颤射频消融术后复发的独立危险因素,绘制受试者操作特征(ROC)曲线分析MFAP4对房颤射频消融术后复发的预测价值。结果:复发组MFAP4、TGF-β1水平、左心房内径(LAD)、BMI均超过未复发组(P<0.05),复发组左心室射血分数(LVEF)低于未复发组(P<0.05),而且阵发性房颤及持续房颤术后复发患者MFAP4、TGF-β1水平、LAD均超过本组内未复发患者(P<0.05)。MFAP4与TGF-β1、LAD呈正相关关系(P<0.05)。Logistic回归分析房颤射频消融术后复发的独立危险因素有MFAP4、TGF-β1、LAD。经ROC曲线分析显示,MFAP4预测房颤射频消融术后复发的ROC曲线下面积0.888(P=0.000),取最佳截断值19.295 ng/mL,其敏感性77.3%,特异性77.2%。复发组再入院、总的不良事件发生率明显高于未复发组,差异有统计学意义(P<0.05)。结论:MFAP4在房颤射频消融术后复发患者中明显升高,是预测房颤射频消融术后复发的独立危险因素之一,具有一定的临床应用价值。展开更多
Structural design simultaneously governed by earthquakes and environmental vibrations has received a lot of attention in recent years.Base-isolated composite structures are typically used in the above-mentioned struct...Structural design simultaneously governed by earthquakes and environmental vibrations has received a lot of attention in recent years.Base-isolated composite structures are typically used in the above-mentioned structural design.The corresponding analysis involves validating structural safety under earthquakes and human comfort under environmental vibrations through a time-history analysis.Thus,a reasonable damping model is essential.In this work,the representatives of viscous damping model and rate-independent damping model,namely the Rayleigh damping model and uniform damping model,were adopted to investigate the influence of damping models on the time-history analysis of such structural designs.The energy dissipation characteristics of the above-mentioned damping models were illustrated via a dynamic test of recycled aggregate concrete specimens.A case study was performed on a base-isolated steelconcrete composite structure.The dynamic responses under the excitation of earthquakes and environmental vibrations were compared using different damping models.The uniform damping model was found to be more flexible than the Rayleigh damping model in dealing with excitations with different frequency components.The uniform damping model is both theoretically advantageous and easy to use,demonstrating its potential in dynamic analysis of structures designed simultaneously governed by earthquakes and environmental vibrations.展开更多
文摘Structural design simultaneously governed by earthquakes and environmental vibrations has received a lot of attention in recent years.Base-isolated composite structures are typically used in the above-mentioned structural design.The corresponding analysis involves validating structural safety under earthquakes and human comfort under environmental vibrations through a time-history analysis.Thus,a reasonable damping model is essential.In this work,the representatives of viscous damping model and rate-independent damping model,namely the Rayleigh damping model and uniform damping model,were adopted to investigate the influence of damping models on the time-history analysis of such structural designs.The energy dissipation characteristics of the above-mentioned damping models were illustrated via a dynamic test of recycled aggregate concrete specimens.A case study was performed on a base-isolated steelconcrete composite structure.The dynamic responses under the excitation of earthquakes and environmental vibrations were compared using different damping models.The uniform damping model was found to be more flexible than the Rayleigh damping model in dealing with excitations with different frequency components.The uniform damping model is both theoretically advantageous and easy to use,demonstrating its potential in dynamic analysis of structures designed simultaneously governed by earthquakes and environmental vibrations.
