目的:评估无水乙醇注射Marshall静脉(vein of Marshall,VOM)在持续性心房扑动(简称房扑)、心房颤动(简称房颤)二尖瓣峡部线性消融中的有效性和安全性。方法:收集2019年9月—2020年5月上海市胸科医院采用射频消融+无水乙醇注射VOM治疗持...目的:评估无水乙醇注射Marshall静脉(vein of Marshall,VOM)在持续性心房扑动(简称房扑)、心房颤动(简称房颤)二尖瓣峡部线性消融中的有效性和安全性。方法:收集2019年9月—2020年5月上海市胸科医院采用射频消融+无水乙醇注射VOM治疗持续性房扑、房颤患者72例(VOM组)的临床资料,同时选择采用左房线性消融治疗持续性房扑、房颤患者72例作为对照(对照组)。入选患者均行二尖瓣峡部线性消融手术,术中验证二尖瓣峡部线阻断情况,术后随访房性心律失常和心包积液发生情况,均随访12个月以上。结果:VOM组术中验证二尖瓣峡部线阻断63例,其中需要联合心内和心外膜补点消融达到二尖瓣峡部线14例,未能阻断二尖瓣峡部线9例。对照组术中验证二尖瓣峡部线53例,未能阻断19例。随访12~20个月,VOM组房性心律失常复发20例,而对照组房性心律失常复发30例。结论:在持续性房扑、房颤消融治疗中,经VOM行无水乙醇注射能有效阻断二尖瓣峡部线性传导,有助于提高二尖瓣峡部线成功率,减少房颤消融术中二尖瓣峡部相关的房扑发生率,且不增加严重并发症的发生率。展开更多
中年男性,因心房颤动消融术后7月余反复心悸入院,心电图提示房性心动过速(简称房速),电生理检查提示起源左侧房速,电激动标测提示二尖瓣峡部局灶性房速,给予45W AI 450 15 mL/min冷盐水射频消融,消融后心电传导顺序改变,心动周期不变;...中年男性,因心房颤动消融术后7月余反复心悸入院,心电图提示房性心动过速(简称房速),电生理检查提示起源左侧房速,电激动标测提示二尖瓣峡部局灶性房速,给予45W AI 450 15 mL/min冷盐水射频消融,消融后心电传导顺序改变,心动周期不变;重新标测,提示环右肺静脉折返,消融无效;再次标测,提示左上肺电激动最早,于左肺静脉嵴部进行线性隔离,消融过程中心动过速终止,电生理检查未再诱发心动过速,消融有效部位的二尖瓣峡部及左肺静脉脊部均为Marshall静脉分布区域,可能存在心外膜传导,Marshall静脉参与的折返性心动过速。展开更多
The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic characteristics.Therefore,this paper uses an improved delayed detached eddy simulation(ID...The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic characteristics.Therefore,this paper uses an improved delayed detached eddy simulation(IDDES)method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under crosswinds.The effects of marshaling lengths(varying from 3-car to 8-car groups)on the train’s aerodynamic performance,surface pressure,and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes(N-S)equations.The results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle cars.Conversely,the marshaling lengths are negatively correlated with the time-average side force coefficient(CS)and time-average lift force coefficient(Cl)of the tail car.Compared to the tail car of the 3-car groups,the CS and Cl fell by 27.77%and 18.29%,respectively,for the tail car of the 8-car groups.It is essential to pay more attention to the operational safety of the head car,as it exhibits the highest time average CS.Additionally,the mean pressure difference between the two sides of the tail car body increased with the marshaling lengths,and the side force direction on the tail car was opposite to that of the head and middle cars.Furthermore,the turbulent kinetic energy of the wake structure on the windward side quickly decreased as marshaling lengths increased.展开更多
The railway mobile communication system is undergoing a smooth transition from the Global System for Mobile Communications-Railway(GSM-R)to the Railway 5G.In this paper,an empirical path loss model based on a large am...The railway mobile communication system is undergoing a smooth transition from the Global System for Mobile Communications-Railway(GSM-R)to the Railway 5G.In this paper,an empirical path loss model based on a large amount of measured data is established to predict the path loss in the Railway 5G marshalling yard scenario.According to the different characteristics of base station directional antennas,the antenna gain is verified.Then we propose the position of the breakpoint in the antenna propagation area,and based on the breakpoint segmentation,a large-scale statistical model for marshalling yards is established.展开更多
In Senegal, basalt aggregates are the aggregates used for the production of asphalt. They are also in some condition in base layer. However, the only licensed and operated basalt quarry in the west-central part of the...In Senegal, basalt aggregates are the aggregates used for the production of asphalt. They are also in some condition in base layer. However, the only licensed and operated basalt quarry in the west-central part of the country is finished and has reached very important depths thus constituting an environmental threat. This is how quartzite present in the east of the country precisely in the department of Bakel would constitute an alternative to basalt. For this purpose, the performance of two bituminous concretes based on quartzite and basalt was compared. One is made from Diack basalt aggregates, considered as the reference aggregate for asphalt in Senegal and the other is based on Bakel quartzite aggregates, they are both class 0/14. The mechanical performance of two bituminous concretes is evaluated using the Marshall method. The results obtained from the marshall tests give compactness values between 94% and 97% representing the limits laid down in the technical specifications, the creep values for quartzite-based asphalt concrete, while respecting the limit values, are higher than those obtained with basalt aggregates. Thus showing that the former is less resistant to deformation than the former. For both bituminous mixtures, the stability values remain above the minimum value of 1000 kgf set by the specifications. The water resistance test carried out on the two bituminous concretes based on basalt aggregate and quartzite aggregate gives values of immersion/compression ratio (R’c/Rc) equal to 0.72 and 0.82 respectively. These values are above the minimum required value (0.70) in the technical specifications in Senegal.展开更多
文摘目的:评估无水乙醇注射Marshall静脉(vein of Marshall,VOM)在持续性心房扑动(简称房扑)、心房颤动(简称房颤)二尖瓣峡部线性消融中的有效性和安全性。方法:收集2019年9月—2020年5月上海市胸科医院采用射频消融+无水乙醇注射VOM治疗持续性房扑、房颤患者72例(VOM组)的临床资料,同时选择采用左房线性消融治疗持续性房扑、房颤患者72例作为对照(对照组)。入选患者均行二尖瓣峡部线性消融手术,术中验证二尖瓣峡部线阻断情况,术后随访房性心律失常和心包积液发生情况,均随访12个月以上。结果:VOM组术中验证二尖瓣峡部线阻断63例,其中需要联合心内和心外膜补点消融达到二尖瓣峡部线14例,未能阻断二尖瓣峡部线9例。对照组术中验证二尖瓣峡部线53例,未能阻断19例。随访12~20个月,VOM组房性心律失常复发20例,而对照组房性心律失常复发30例。结论:在持续性房扑、房颤消融治疗中,经VOM行无水乙醇注射能有效阻断二尖瓣峡部线性传导,有助于提高二尖瓣峡部线成功率,减少房颤消融术中二尖瓣峡部相关的房扑发生率,且不增加严重并发症的发生率。
文摘中年男性,因心房颤动消融术后7月余反复心悸入院,心电图提示房性心动过速(简称房速),电生理检查提示起源左侧房速,电激动标测提示二尖瓣峡部局灶性房速,给予45W AI 450 15 mL/min冷盐水射频消融,消融后心电传导顺序改变,心动周期不变;重新标测,提示环右肺静脉折返,消融无效;再次标测,提示左上肺电激动最早,于左肺静脉嵴部进行线性隔离,消融过程中心动过速终止,电生理检查未再诱发心动过速,消融有效部位的二尖瓣峡部及左肺静脉脊部均为Marshall静脉分布区域,可能存在心外膜传导,Marshall静脉参与的折返性心动过速。
基金supported by Wuyi University Hong Kong and Macao Joint Research and Development Fund(GrantsNos.2021WGALH15,2019WGALH17,2019WGALH15)the National Natural Science Foundation of China-Guangdong Joint Fund(GrantsNo.2019A1515111052)+2 种基金the National Natural Science Foundation of China(Grant No.52202426)a grant from the Research Grants Council(RGC)of the Hong Kong Special Administrative Region(SAR),China(Grants No.15205723)a grant from the Hong Kong Polytechnic University(Grant No.P0045325).
文摘The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic characteristics.Therefore,this paper uses an improved delayed detached eddy simulation(IDDES)method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under crosswinds.The effects of marshaling lengths(varying from 3-car to 8-car groups)on the train’s aerodynamic performance,surface pressure,and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes(N-S)equations.The results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle cars.Conversely,the marshaling lengths are negatively correlated with the time-average side force coefficient(CS)and time-average lift force coefficient(Cl)of the tail car.Compared to the tail car of the 3-car groups,the CS and Cl fell by 27.77%and 18.29%,respectively,for the tail car of the 8-car groups.It is essential to pay more attention to the operational safety of the head car,as it exhibits the highest time average CS.Additionally,the mean pressure difference between the two sides of the tail car body increased with the marshaling lengths,and the side force direction on the tail car was opposite to that of the head and middle cars.Furthermore,the turbulent kinetic energy of the wake structure on the windward side quickly decreased as marshaling lengths increased.
基金supported in part by the Fundamental Research Funds for the Central Universities under Grant No.2022JBXT001in part by NS⁃FC under Grant No.62171021+1 种基金in part by the Project of China State Rail⁃way Group under Grant No.P2021G012in part by ZTE Industry⁃University⁃Institute Cooperation Funds under Grant No.I21L00220.
文摘The railway mobile communication system is undergoing a smooth transition from the Global System for Mobile Communications-Railway(GSM-R)to the Railway 5G.In this paper,an empirical path loss model based on a large amount of measured data is established to predict the path loss in the Railway 5G marshalling yard scenario.According to the different characteristics of base station directional antennas,the antenna gain is verified.Then we propose the position of the breakpoint in the antenna propagation area,and based on the breakpoint segmentation,a large-scale statistical model for marshalling yards is established.
文摘In Senegal, basalt aggregates are the aggregates used for the production of asphalt. They are also in some condition in base layer. However, the only licensed and operated basalt quarry in the west-central part of the country is finished and has reached very important depths thus constituting an environmental threat. This is how quartzite present in the east of the country precisely in the department of Bakel would constitute an alternative to basalt. For this purpose, the performance of two bituminous concretes based on quartzite and basalt was compared. One is made from Diack basalt aggregates, considered as the reference aggregate for asphalt in Senegal and the other is based on Bakel quartzite aggregates, they are both class 0/14. The mechanical performance of two bituminous concretes is evaluated using the Marshall method. The results obtained from the marshall tests give compactness values between 94% and 97% representing the limits laid down in the technical specifications, the creep values for quartzite-based asphalt concrete, while respecting the limit values, are higher than those obtained with basalt aggregates. Thus showing that the former is less resistant to deformation than the former. For both bituminous mixtures, the stability values remain above the minimum value of 1000 kgf set by the specifications. The water resistance test carried out on the two bituminous concretes based on basalt aggregate and quartzite aggregate gives values of immersion/compression ratio (R’c/Rc) equal to 0.72 and 0.82 respectively. These values are above the minimum required value (0.70) in the technical specifications in Senegal.
