0ctogenarians represent the fastest growing group of patients undergoing percutaneous coronary intervention(PCI),now constituting more than one in five patients treated with PCI in real-world practice.[1,2]Comparing c...0ctogenarians represent the fastest growing group of patients undergoing percutaneous coronary intervention(PCI),now constituting more than one in five patients treated with PCI in real-world practice.[1,2]Comparing coronary lesion characteristics of patients aged<≥80 years to those≥80 years undergoing PCI,the octogenarians have a higher prevalence of calcified and ostial lesions,tortuous coronary anatomy,multi-vessel disease and left main stem(LMS)stenosis.⑶Furthermore,they often have greater ischemic burden than their younger counterparts,suggesting an even greater benefit following revascularization.展开更多
High Altitude Platform(HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With ...High Altitude Platform(HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With analysis on HAP movement models for predicting the geographical coverage in the cases of shift horizontally and vertically,yaw,roll and pitch,the mechanisms of steerable antennas movement compensation are investigated.The mechanism is applied to a scenario of 127 cell architecture,with a cell cluster size of four.By the simulation results of Carrier to Interference Ratio(CIR),the steerable antenna movement compensation mechanism decrease influence of HAP movement and guarantee effective coverage of the service area.展开更多
BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter clo...BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter closure of PVL is technically demanding and challenging.CASE SUMMARY A 68-year-old man presented with degenerative mitral regurgitation with heart failure,New York Heart Association functional class 3.He received bioprosthetic mitral valve replacement in December 2019.PVL was noted at the location of the aorto-mitral curtain in transesophageal echocardiography without signs of endocarditis or dehiscence of the bioprosthetic valve.Transseptal transcatheter closure of the mitral PVL was performed efficiently using the EchoNavigator virtual marker and Agilis NxT steerable introducer.CONCLUSION This case highlights that the EchoNavigator virtual marker and Agilis NxT steerable introducer can facilitate transseptal transcatheter closure of mitral PVL by reducing the procedure time and contrast media.展开更多
During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such ...During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such as deep burial depth (>2000 m), thin coal sweet spot (3 m), and significant short-distance structural fluctuations. The challenges caused a high risk of missing targets and running out of the target layers, as well as difficulties in cementing and completion due to uneven well trajectories. To address these challenges, this paper focuses on solving the issues through detailed precise geological modeling, optimized trajectory design, and accurate seismic geology Steerable Drilling. 1) Based on reasonable velocity field construction and Time-Depth transformation, a precise directional model is constructed using the layer-by-layer approximation principle with reference to marker layers, improving the accuracy of the target spot and avoiding premature or delayed entry into the target;2) Based on a precise geological model, the dip angle of the strata ahead and the development of sweet spots are clearly defined, enabling optimized trajectory design for horizontal wells;3) Using “1 + N” dynamic modeling to update the geological model in real-time during the drilling process, and actively guide the drill bit through the horizontal segment smoothly by using multi-information judgment of the drill bit position. The actual drilling of 80 completed horizontal wells in this area show: That this approach effectively ensures the smooth trajectory and high-quality drilling rate of the horizontal well in the coal seam, providing a basis for subsequent hydraulic fracturing and increasing single-well production. At the same time, it has certain potential value and significance for similar coalbed methane developments under similar geological conditions.展开更多
目前海上钻井作业日趋复杂,在水平井中需要在钻进过程中进行导向,以确保其始终保持在开发层中,尽管随钻测井(Logging while Drilling,LwD)技术已被广泛应用,但有时基于薄开采区上下厚度的限制,这种地质导向只能通过特定的设备(旋转导向...目前海上钻井作业日趋复杂,在水平井中需要在钻进过程中进行导向,以确保其始终保持在开发层中,尽管随钻测井(Logging while Drilling,LwD)技术已被广泛应用,但有时基于薄开采区上下厚度的限制,这种地质导向只能通过特定的设备(旋转导向)来实现,当井打到储层与非储层间交界处时,LwD可以检测到,由于有了旋转导向便可立即调整,非导向设备无法用于矫正井眼轨迹,因此需要使用LwD加旋转导向联合作业。基于此,本文就针对上述问题展开论述,以供参考。展开更多
文摘0ctogenarians represent the fastest growing group of patients undergoing percutaneous coronary intervention(PCI),now constituting more than one in five patients treated with PCI in real-world practice.[1,2]Comparing coronary lesion characteristics of patients aged<≥80 years to those≥80 years undergoing PCI,the octogenarians have a higher prevalence of calcified and ostial lesions,tortuous coronary anatomy,multi-vessel disease and left main stem(LMS)stenosis.⑶Furthermore,they often have greater ischemic burden than their younger counterparts,suggesting an even greater benefit following revascularization.
文摘High Altitude Platform(HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With analysis on HAP movement models for predicting the geographical coverage in the cases of shift horizontally and vertically,yaw,roll and pitch,the mechanisms of steerable antennas movement compensation are investigated.The mechanism is applied to a scenario of 127 cell architecture,with a cell cluster size of four.By the simulation results of Carrier to Interference Ratio(CIR),the steerable antenna movement compensation mechanism decrease influence of HAP movement and guarantee effective coverage of the service area.
文摘BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter closure of PVL is technically demanding and challenging.CASE SUMMARY A 68-year-old man presented with degenerative mitral regurgitation with heart failure,New York Heart Association functional class 3.He received bioprosthetic mitral valve replacement in December 2019.PVL was noted at the location of the aorto-mitral curtain in transesophageal echocardiography without signs of endocarditis or dehiscence of the bioprosthetic valve.Transseptal transcatheter closure of the mitral PVL was performed efficiently using the EchoNavigator virtual marker and Agilis NxT steerable introducer.CONCLUSION This case highlights that the EchoNavigator virtual marker and Agilis NxT steerable introducer can facilitate transseptal transcatheter closure of mitral PVL by reducing the procedure time and contrast media.
文摘During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such as deep burial depth (>2000 m), thin coal sweet spot (3 m), and significant short-distance structural fluctuations. The challenges caused a high risk of missing targets and running out of the target layers, as well as difficulties in cementing and completion due to uneven well trajectories. To address these challenges, this paper focuses on solving the issues through detailed precise geological modeling, optimized trajectory design, and accurate seismic geology Steerable Drilling. 1) Based on reasonable velocity field construction and Time-Depth transformation, a precise directional model is constructed using the layer-by-layer approximation principle with reference to marker layers, improving the accuracy of the target spot and avoiding premature or delayed entry into the target;2) Based on a precise geological model, the dip angle of the strata ahead and the development of sweet spots are clearly defined, enabling optimized trajectory design for horizontal wells;3) Using “1 + N” dynamic modeling to update the geological model in real-time during the drilling process, and actively guide the drill bit through the horizontal segment smoothly by using multi-information judgment of the drill bit position. The actual drilling of 80 completed horizontal wells in this area show: That this approach effectively ensures the smooth trajectory and high-quality drilling rate of the horizontal well in the coal seam, providing a basis for subsequent hydraulic fracturing and increasing single-well production. At the same time, it has certain potential value and significance for similar coalbed methane developments under similar geological conditions.
文摘目前海上钻井作业日趋复杂,在水平井中需要在钻进过程中进行导向,以确保其始终保持在开发层中,尽管随钻测井(Logging while Drilling,LwD)技术已被广泛应用,但有时基于薄开采区上下厚度的限制,这种地质导向只能通过特定的设备(旋转导向)来实现,当井打到储层与非储层间交界处时,LwD可以检测到,由于有了旋转导向便可立即调整,非导向设备无法用于矫正井眼轨迹,因此需要使用LwD加旋转导向联合作业。基于此,本文就针对上述问题展开论述,以供参考。
