目的:比较亲属活体供肾与心脏死亡器官捐献(donation after cardiac death,DCD)供肾肾移植的临床效果。方法:回顾性分析2011-04～2018-01兰州大学第二医院肾移植科同期完成的45例亲属活体供肾(亲属活体供肾组)和21例DCD供肾肾移植受者(...目的:比较亲属活体供肾与心脏死亡器官捐献(donation after cardiac death,DCD)供肾肾移植的临床效果。方法:回顾性分析2011-04～2018-01兰州大学第二医院肾移植科同期完成的45例亲属活体供肾(亲属活体供肾组)和21例DCD供肾肾移植受者(DCD供肾组)的临床资料,比较两组患者移植肾一般情况、肾功能、人肾累积存活率及并发症情况。结果:两组患者性别、BMI、手术时间、住院时长比较,差异无统计学意义(P>0.05),供、受者年龄和透析时间比较,差异有显著统计学意义(P<0.01)。亲属活体供肾组和DCD供肾组受者急性排斥反应分别发生2例(4.4%)和6例(28.6%),两组间差异有统计学意义(P<0.05);移植肾功能延迟恢复分别发生1例(2.2%)和2例(9.5%),两组间差异无统计学意义(P>0.05)。术后1周两组患者血肌酐比较,差异均有统计学意义,且术后患者血肌酐恢复至正常的时间比较,差异有统计学意义(P<0.05或P<0.01);术后2周、1个月、2个月两组患者血肌酐差异均无统计学意义。两组整个随访期的人、肾累积存活率比较,差异无统计学意义。结论:亲属活体供肾与DCD供肾肾移植早期效果类似,活体肾移植在移植肾术后急性排斥反应及肾功能短期恢复方面具有一定优势,但随访期间的人、肾累积存活率相同。展开更多
Two kinds nitride modified layers were obtained on Ti-13Nb-13 Zr surface to improve the wear property via magnetron sputtering and plasma nitriding techniques, respectively. The structures of the modified layer and th...Two kinds nitride modified layers were obtained on Ti-13Nb-13 Zr surface to improve the wear property via magnetron sputtering and plasma nitriding techniques, respectively. The structures of the modified layer and the worn surface after sliding test were characterized using X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The friction and wear behavior of the modified layer against alumina ball was investigated in the absence of lubricant under different loads（1 N and 2 N）. The X-ray diffraction analysis reveals that nitride layer is mainly composed of TiN and Ti2N, while coating film consists of Ti N phase. Friction and wear test indicates that both modified layers can improve the wear resistance compared to untreated Ti-13Nb-13 Zr. Ti N thin film produces very hard surface, but may be easy to cause coating fracture and delamination under high normal load. However, nitride layer exhibits better wear performance. This is attributed to hard compound layer maintained its integrity with the hardened nitrogen diffusion zone during friction and wear process.展开更多
目的针对激光雷达点云稀疏性导致小目标检测精度下降的问题,提出一种伪激光点云增强技术,利用图像与点云融合,对稀疏的小目标几何信息进行补充,提升道路场景下三维目标检测性能。方法首先,使用深度估计网络获取双目图像的深度图,利用激...目的针对激光雷达点云稀疏性导致小目标检测精度下降的问题,提出一种伪激光点云增强技术,利用图像与点云融合,对稀疏的小目标几何信息进行补充,提升道路场景下三维目标检测性能。方法首先,使用深度估计网络获取双目图像的深度图,利用激光点云对深度图进行深度校正,减少深度估计误差;其次,采用语义分割的方法获取图像的前景区域,仅将前景区域对应的深度图映射到三维空间中生成伪激光点云,提升伪激光点云中前景点的数量占比;最后,根据不同的观测距离对伪激光点云进行不同线数的下采样,并与原始激光点云进行融合作为最终的输入点云数据。结果在KITTI(Karlsruhe Institute of Technology and Toyota Technological Institute at Chicago)数据集上的实验结果表明,该方法能够提升多个最新网络框架的小目标检测精度,以典型网络SECOND(sparsely embedded convolutional detection)、MVX-Net(multimodal voxelnet for 3D object detection)、Voxel-RCNN为例,在困难等级下,三维目标检测精度分别获得8.65%、7.32%和6.29%的大幅提升。结论该方法适用于所有以点云为输入的目标检测网络,并显著提升了多个目标检测网络在道路场景下的小目标检测性能。该方法具备有效性与通用性。展开更多
文摘目的:比较亲属活体供肾与心脏死亡器官捐献(donation after cardiac death,DCD)供肾肾移植的临床效果。方法:回顾性分析2011-04～2018-01兰州大学第二医院肾移植科同期完成的45例亲属活体供肾(亲属活体供肾组)和21例DCD供肾肾移植受者(DCD供肾组)的临床资料,比较两组患者移植肾一般情况、肾功能、人肾累积存活率及并发症情况。结果:两组患者性别、BMI、手术时间、住院时长比较,差异无统计学意义(P>0.05),供、受者年龄和透析时间比较,差异有显著统计学意义(P<0.01)。亲属活体供肾组和DCD供肾组受者急性排斥反应分别发生2例(4.4%)和6例(28.6%),两组间差异有统计学意义(P<0.05);移植肾功能延迟恢复分别发生1例(2.2%)和2例(9.5%),两组间差异无统计学意义(P>0.05)。术后1周两组患者血肌酐比较,差异均有统计学意义,且术后患者血肌酐恢复至正常的时间比较,差异有统计学意义(P<0.05或P<0.01);术后2周、1个月、2个月两组患者血肌酐差异均无统计学意义。两组整个随访期的人、肾累积存活率比较,差异无统计学意义。结论:亲属活体供肾与DCD供肾肾移植早期效果类似,活体肾移植在移植肾术后急性排斥反应及肾功能短期恢复方面具有一定优势,但随访期间的人、肾累积存活率相同。
基金Funded by the National Natural Science Foundation of China(Nos.51671140 and 51474154)the Shanxi Province Programs for Graduate Education Reform(2015JG42)
文摘Two kinds nitride modified layers were obtained on Ti-13Nb-13 Zr surface to improve the wear property via magnetron sputtering and plasma nitriding techniques, respectively. The structures of the modified layer and the worn surface after sliding test were characterized using X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The friction and wear behavior of the modified layer against alumina ball was investigated in the absence of lubricant under different loads（1 N and 2 N）. The X-ray diffraction analysis reveals that nitride layer is mainly composed of TiN and Ti2N, while coating film consists of Ti N phase. Friction and wear test indicates that both modified layers can improve the wear resistance compared to untreated Ti-13Nb-13 Zr. Ti N thin film produces very hard surface, but may be easy to cause coating fracture and delamination under high normal load. However, nitride layer exhibits better wear performance. This is attributed to hard compound layer maintained its integrity with the hardened nitrogen diffusion zone during friction and wear process.
文摘目的针对激光雷达点云稀疏性导致小目标检测精度下降的问题,提出一种伪激光点云增强技术,利用图像与点云融合,对稀疏的小目标几何信息进行补充,提升道路场景下三维目标检测性能。方法首先,使用深度估计网络获取双目图像的深度图,利用激光点云对深度图进行深度校正,减少深度估计误差;其次,采用语义分割的方法获取图像的前景区域,仅将前景区域对应的深度图映射到三维空间中生成伪激光点云,提升伪激光点云中前景点的数量占比;最后,根据不同的观测距离对伪激光点云进行不同线数的下采样,并与原始激光点云进行融合作为最终的输入点云数据。结果在KITTI(Karlsruhe Institute of Technology and Toyota Technological Institute at Chicago)数据集上的实验结果表明,该方法能够提升多个最新网络框架的小目标检测精度,以典型网络SECOND(sparsely embedded convolutional detection)、MVX-Net(multimodal voxelnet for 3D object detection)、Voxel-RCNN为例,在困难等级下,三维目标检测精度分别获得8.65%、7.32%和6.29%的大幅提升。结论该方法适用于所有以点云为输入的目标检测网络,并显著提升了多个目标检测网络在道路场景下的小目标检测性能。该方法具备有效性与通用性。
