A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage cons...A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.展开更多
Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation （TAVI） procedures remain an is- sue. Benefit of oversizing strategies to prevent them isn＇t well established. We com...Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation （TAVI） procedures remain an is- sue. Benefit of oversizing strategies to prevent them isn＇t well established. We compared different level of oversizing in our cohort of con- secutive patients to address if severe oversizing compared to normal sizing had an impact on post-procedural outcomes. Methods From January 2010 to August 2013, consecutive patients were referred for TAVI with preoperative Multislice-CT （MSCT） and the procedures were achieved using Edwards Sapien~ or Corevalve devices~. Retrospectively, according to pre-procedural MSCT and the valve size, pa- tients were classified into three groups： normal, moderate and severe oversizing; depending on the ratio between the prosthesis area and the annulus area indexed and measured on MSCT. Main endpoint was mid-term mortality and secondary endpoints were the Valve Academic Research Consortium （VARC-2） endpoints. Results Two hundred and sixty eight patients had a MSCT and underwent TAVI procedure, with mainly Corevalve~. While all-cause and cardiovascular mortality rates were similar in all groups, post-procedural new pacemaker （PM） implantation rate was significantly higher in the severe oversizing group （P = 0.03）, while we observed more in-hospital congestive heart-failure （P = 0.02） in the normal sizing group. There was a trend toward more moderate to severe aortic regurgitation （AR） in the normal sizing group （P = 0.07）. Conclusions Despite a higher rate of PM implantation, oversizing based on this ratio reduces aortic leak with lower rates of post-procedural complications and a similar mid-term survival.展开更多
BACKGROUND：Endovascular repair of mycotic aneurysm is an alternative to open repair if the patho-anatomy is suitable. The aortic size above and below the mycotic aneurysm may be small. METHODS： A retrospective revie...BACKGROUND：Endovascular repair of mycotic aneurysm is an alternative to open repair if the patho-anatomy is suitable. The aortic size above and below the mycotic aneurysm may be small. METHODS： A retrospective review was made of prospectively collected departmenta computerised database. RESULTS： Three oriental patients with juxta- and infra-renal mycotic aortic aneurysms with a small aortic diameter of 17 mm to 18 mm underwent successful emergency endovascular treatment using Cook Zenith ELSE stentgraffs. These are ancillary devices aimed at iliac extensions usually. CONCLUSIONS： This is to our knowledge the first case series of Cook Zenith ELSE iliac component endografts for the treatment of aortic mycotic aneurysms with small aortae, and short- and mid-term results are encouraging.展开更多
According to the weather men last winter was one of theworst in living memory.We live in the depths of the country,and my whole family a-gree that it was certainly a winter we shall never forget.Snow be-gan to fall at...According to the weather men last winter was one of theworst in living memory.We live in the depths of the country,and my whole family a-gree that it was certainly a winter we shall never forget.Snow be-gan to fall at round about the beginning of the New Year and con-tinued on and off for approximately ten days.At first we were all thrilleds to see it.It fell silently and relent-展开更多
基金supported by Chinese National Natural Science Foundation (No. 51809016 and No. 51979152)Chongqing Municipal Natural Science Foundation (No. cstc2019jcyjmsxmX0645)
文摘A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.
文摘Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation （TAVI） procedures remain an is- sue. Benefit of oversizing strategies to prevent them isn＇t well established. We compared different level of oversizing in our cohort of con- secutive patients to address if severe oversizing compared to normal sizing had an impact on post-procedural outcomes. Methods From January 2010 to August 2013, consecutive patients were referred for TAVI with preoperative Multislice-CT （MSCT） and the procedures were achieved using Edwards Sapien~ or Corevalve devices~. Retrospectively, according to pre-procedural MSCT and the valve size, pa- tients were classified into three groups： normal, moderate and severe oversizing; depending on the ratio between the prosthesis area and the annulus area indexed and measured on MSCT. Main endpoint was mid-term mortality and secondary endpoints were the Valve Academic Research Consortium （VARC-2） endpoints. Results Two hundred and sixty eight patients had a MSCT and underwent TAVI procedure, with mainly Corevalve~. While all-cause and cardiovascular mortality rates were similar in all groups, post-procedural new pacemaker （PM） implantation rate was significantly higher in the severe oversizing group （P = 0.03）, while we observed more in-hospital congestive heart-failure （P = 0.02） in the normal sizing group. There was a trend toward more moderate to severe aortic regurgitation （AR） in the normal sizing group （P = 0.07）. Conclusions Despite a higher rate of PM implantation, oversizing based on this ratio reduces aortic leak with lower rates of post-procedural complications and a similar mid-term survival.
文摘BACKGROUND：Endovascular repair of mycotic aneurysm is an alternative to open repair if the patho-anatomy is suitable. The aortic size above and below the mycotic aneurysm may be small. METHODS： A retrospective review was made of prospectively collected departmenta computerised database. RESULTS： Three oriental patients with juxta- and infra-renal mycotic aortic aneurysms with a small aortic diameter of 17 mm to 18 mm underwent successful emergency endovascular treatment using Cook Zenith ELSE stentgraffs. These are ancillary devices aimed at iliac extensions usually. CONCLUSIONS： This is to our knowledge the first case series of Cook Zenith ELSE iliac component endografts for the treatment of aortic mycotic aneurysms with small aortae, and short- and mid-term results are encouraging.
文摘According to the weather men last winter was one of theworst in living memory.We live in the depths of the country,and my whole family a-gree that it was certainly a winter we shall never forget.Snow be-gan to fall at round about the beginning of the New Year and con-tinued on and off for approximately ten days.At first we were all thrilleds to see it.It fell silently and relent-
