目的:比较一期腹腔镜胆囊切除(LC)联合胆总管探查取石(LCBDE)与分期内镜取石(ERCP)和LC治疗胆囊结石合并胆总管结石的临床效果。方法:回顾性分析2013年1月—2014年6月在西安交通大学第一附属医院行微创治疗的112例胆囊结石合并胆总管结...目的:比较一期腹腔镜胆囊切除(LC)联合胆总管探查取石(LCBDE)与分期内镜取石(ERCP)和LC治疗胆囊结石合并胆总管结石的临床效果。方法:回顾性分析2013年1月—2014年6月在西安交通大学第一附属医院行微创治疗的112例胆囊结石合并胆总管结石患者资料,其中52例行一期LC+LCBDE(LCBDE组),60例行ERCP后24 h或择期行LC(ERCP组),比较两组相关临床指标。结果:除LCBDE组平均年龄小于ERCP组外(42.4岁vs.57.4岁,P<0.05),两组其余一般资料均具有可比性。两组均无死亡病例,手术成功率(94.3%vs.98.4%)、总并发症发生率(8.2%vs.10.1%)、结石残余发生率(2.0%vs.1.7%)等差异均无统计学意义(P>0.05);ERCP组术后高淀粉酶血症发生率明显高于LCBDE组(16.9%vs.4.1%,P<0.05),但均为单纯性淀粉酶升高;与ERCP组比较,LCBDE组术后住院时间更短(4.9 d vs.6.3 d),总住院费用减少(21 685.9元vs.30 354.3元),但LCBDE组手术时间明显延长(117.1 min vs.97.4 min)(均P<0.05)。结论:一期LC+LCBDE或分期ERCP+LC治疗胆囊结石合并胆总管结石均安全、有效,可根据患者情况选择应用。展开更多
This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker （DCCB） contact system. A three-dimensional magneto-hydrodyna...This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker （DCCB） contact system. A three-dimensional magneto-hydrodynamic （MHD） model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.展开更多
文摘目的:比较一期腹腔镜胆囊切除(LC)联合胆总管探查取石(LCBDE)与分期内镜取石(ERCP)和LC治疗胆囊结石合并胆总管结石的临床效果。方法:回顾性分析2013年1月—2014年6月在西安交通大学第一附属医院行微创治疗的112例胆囊结石合并胆总管结石患者资料,其中52例行一期LC+LCBDE(LCBDE组),60例行ERCP后24 h或择期行LC(ERCP组),比较两组相关临床指标。结果:除LCBDE组平均年龄小于ERCP组外(42.4岁vs.57.4岁,P<0.05),两组其余一般资料均具有可比性。两组均无死亡病例,手术成功率(94.3%vs.98.4%)、总并发症发生率(8.2%vs.10.1%)、结石残余发生率(2.0%vs.1.7%)等差异均无统计学意义(P>0.05);ERCP组术后高淀粉酶血症发生率明显高于LCBDE组(16.9%vs.4.1%,P<0.05),但均为单纯性淀粉酶升高;与ERCP组比较,LCBDE组术后住院时间更短(4.9 d vs.6.3 d),总住院费用减少(21 685.9元vs.30 354.3元),但LCBDE组手术时间明显延长(117.1 min vs.97.4 min)(均P<0.05)。结论:一期LC+LCBDE或分期ERCP+LC治疗胆囊结石合并胆总管结石均安全、有效,可根据患者情况选择应用。
基金supported by National Natural Science Foundation of China (Nos.51177124,51007072)the Doctoral Foundation of Ministry of Education of China (No.20110201120069)
文摘This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker （DCCB） contact system. A three-dimensional magneto-hydrodynamic （MHD） model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.
