Objectives:Distal segment aortic enlargement(DSAE)is a common complication that influences the long-term prognosis of type B aortic dissection(TBAD)after thoracic endovascular aortic repair(TEVAR).In this study,a mult...Objectives:Distal segment aortic enlargement(DSAE)is a common complication that influences the long-term prognosis of type B aortic dissection(TBAD)after thoracic endovascular aortic repair(TEVAR).In this study,a multivariate analysis was performed to find potential factors predictive of DSAE.Methods:A single-center retrospective study was performed from 1999 to 2016.Included in the study were complicated TBAD patients who underwent TEVAR with uncovered residual tears.Based on the diameter of the distal segment of the uncovered aorta,we assigned patients to an enlargement group and a non-enlargement group.Data extracted from the medical records included demographic and clinical characteristics and followup computed tomography angiography data.The primary endpoints were the all-cause mortality and the presumably aortic-related events that required reintervention during the follow-up period.Results:For the 333 patients,all-cause mortality was 38(11.41%),and 76(22.82%)patients underwent reintervention.A total of 70(21.02%)patients experienced DSAE,among them were 2 patients who died of aortic rupture and 58 patients who accepted reintervention.Multivariate analysis reviewed independent risk factors of postoperative DSAE,including current smoking,the residual length of the patent false lumen,the postoperative number of dissection tears in the thoracic aorta and type III aortic arch;as well as protective factors,including the application of a restrictive bare stent(RBS),the length of covered stent in the descending thoracic aorta,and the distance from the residual first tear to the left subclavian artery(LSA).Conclusion:DSAE after TEVAR for patients with a complicated TBAD can be influenced by their current smoking habit,the residual length of patent false lumen,the postoperative number of dissection tears in the thoracic aorta and the aortic arch type.Meanwhile,RBS usage,the length of the covered stent in the descending thoracic aorta and the distance from the residual first tear to the LSA could have positive effect on the prognosis.展开更多
视觉同时定位与地图构建(Simultaneous localization and mapping,SLAM)过程中,动态物体引入的干扰信息会严重影响定位精度。通过剔除动态对象,修复空洞区域解决动态场景下的SLAM问题。采用Mask-RCNN获取语义信息,结合对极几何方法对动...视觉同时定位与地图构建(Simultaneous localization and mapping,SLAM)过程中,动态物体引入的干扰信息会严重影响定位精度。通过剔除动态对象,修复空洞区域解决动态场景下的SLAM问题。采用Mask-RCNN获取语义信息,结合对极几何方法对动态对象进行剔除。使用关键帧像素加权映射的方式对RGB和深度图空洞区域进行逐像素恢复。依据深度图相邻像素相关性使用区域生长算法完善深度信息。在TUM数据集上的实验结果表明,位姿估计精度较ORB-SLAM2平均提高85.26%,较DynaSLAM提高28.54%,在实际场景中进行测试依旧表现良好。展开更多
在自组网中,ZRP的域间路由维护策略使ZRP具有较多的丢包数目和较多的路由重发现次数。前者使ZRP的数据包投递率较低,从而使其可靠性较低;后者使ZRP的传输时延和路由开销较高。针对上述问题,提出一种基于分段修复的区域路由协议SRZRP(Seg...在自组网中,ZRP的域间路由维护策略使ZRP具有较多的丢包数目和较多的路由重发现次数。前者使ZRP的数据包投递率较低,从而使其可靠性较低;后者使ZRP的传输时延和路由开销较高。针对上述问题,提出一种基于分段修复的区域路由协议SRZRP(Segmented Repairment based Zone Routing Protocol)。在SRZRP中,每个节点通过维护一个基于域内拓扑结构的有向无环图来保存到达其域内每个节点的多条备份路由,尽量利用备份分段路由进行域间路由修复。理论分析表明,SRZRP具有较高的可靠性。仿真结果表明,SRZRP提高了数据包投递率,说明SRZRP提高了协议的可靠性;同时,SRZRP降低了平均端到端时延和路由开销。展开更多
基金supported by the National Nature Science Foundation of China[grant number 81800403].
文摘Objectives:Distal segment aortic enlargement(DSAE)is a common complication that influences the long-term prognosis of type B aortic dissection(TBAD)after thoracic endovascular aortic repair(TEVAR).In this study,a multivariate analysis was performed to find potential factors predictive of DSAE.Methods:A single-center retrospective study was performed from 1999 to 2016.Included in the study were complicated TBAD patients who underwent TEVAR with uncovered residual tears.Based on the diameter of the distal segment of the uncovered aorta,we assigned patients to an enlargement group and a non-enlargement group.Data extracted from the medical records included demographic and clinical characteristics and followup computed tomography angiography data.The primary endpoints were the all-cause mortality and the presumably aortic-related events that required reintervention during the follow-up period.Results:For the 333 patients,all-cause mortality was 38(11.41%),and 76(22.82%)patients underwent reintervention.A total of 70(21.02%)patients experienced DSAE,among them were 2 patients who died of aortic rupture and 58 patients who accepted reintervention.Multivariate analysis reviewed independent risk factors of postoperative DSAE,including current smoking,the residual length of the patent false lumen,the postoperative number of dissection tears in the thoracic aorta and type III aortic arch;as well as protective factors,including the application of a restrictive bare stent(RBS),the length of covered stent in the descending thoracic aorta,and the distance from the residual first tear to the left subclavian artery(LSA).Conclusion:DSAE after TEVAR for patients with a complicated TBAD can be influenced by their current smoking habit,the residual length of patent false lumen,the postoperative number of dissection tears in the thoracic aorta and the aortic arch type.Meanwhile,RBS usage,the length of the covered stent in the descending thoracic aorta and the distance from the residual first tear to the LSA could have positive effect on the prognosis.
文摘视觉同时定位与地图构建(Simultaneous localization and mapping,SLAM)过程中,动态物体引入的干扰信息会严重影响定位精度。通过剔除动态对象,修复空洞区域解决动态场景下的SLAM问题。采用Mask-RCNN获取语义信息,结合对极几何方法对动态对象进行剔除。使用关键帧像素加权映射的方式对RGB和深度图空洞区域进行逐像素恢复。依据深度图相邻像素相关性使用区域生长算法完善深度信息。在TUM数据集上的实验结果表明,位姿估计精度较ORB-SLAM2平均提高85.26%,较DynaSLAM提高28.54%,在实际场景中进行测试依旧表现良好。
文摘在自组网中,ZRP的域间路由维护策略使ZRP具有较多的丢包数目和较多的路由重发现次数。前者使ZRP的数据包投递率较低,从而使其可靠性较低;后者使ZRP的传输时延和路由开销较高。针对上述问题,提出一种基于分段修复的区域路由协议SRZRP(Segmented Repairment based Zone Routing Protocol)。在SRZRP中,每个节点通过维护一个基于域内拓扑结构的有向无环图来保存到达其域内每个节点的多条备份路由,尽量利用备份分段路由进行域间路由修复。理论分析表明,SRZRP具有较高的可靠性。仿真结果表明,SRZRP提高了数据包投递率,说明SRZRP提高了协议的可靠性;同时,SRZRP降低了平均端到端时延和路由开销。
