Left ventricular assist devices(LVAD)are increasingly become common as life prolonging therapy in patients with advanced heart failure.Current devices are now used as definitive treatment in some patients given the im...Left ventricular assist devices(LVAD)are increasingly become common as life prolonging therapy in patients with advanced heart failure.Current devices are now used as definitive treatment in some patients given the improved durability of continuous flow pumps.Unfortunately,continuous flow LVADs are fraught with complications such as gastrointestinal(GI)bleeding that are primarily attributed to the formation of arteriovenous malformations.With frequent GI bleeding,antiplatelet and anticoagulation therapies are usually discontinued increasing the risk of life-threatening events.Small bowel bleeds account for 15%as the source and patients often undergo multiple endoscopic procedures.Treatment strategies include resuscitative measures and endoscopic therapies.Medical treatment is with octreotide.Novel treatment options include thalidomide,angiotensin converting enzyme inhibitors/angiotensinⅡreceptor blockers,estrogen-based hormonal therapies,doxycycline,desmopressin and bevacizumab.Current research has explored the mechanism of frequent GI bleeds in this population,including destruction of von Willebrand factor,upregulation of tissue factor,vascular endothelial growth factor,tumor necrosis factor-α,tumor growth factor-β,and angiopoetin-2,and downregulation of angiopoetin-1.In addition,healthcare resource utilization is only increasing in this patient population with higher admissions,readmissions,blood product utilization,and endoscopy.While some of the novel endoscopic and medical therapies for LVAD bleeds are still in their development stages,these tools will yet be crucial as the number of LVAD placements will likely only increase in the coming years.展开更多
The increasing popularity of smart mobile devices and the rise of online services has increased the requirements for efficient dissemination of social video contents. In this paper,we study the problem of distributing...The increasing popularity of smart mobile devices and the rise of online services has increased the requirements for efficient dissemination of social video contents. In this paper,we study the problem of distributing video from cloud server to users in partially connected cooperative D2 D network using network coding. In such a scenario, the transmission conflicts occur from simultaneous transmissions of multiple devices, and the scheduling decision should be made not only on the encoded packets but also on the set of transmitting devices. We analyze the lower bound and give an integer linear formulation of the joint optimization problem over the set of transmitting devices and the packet combinations.We also propose a heuristic solution for this setup using a conflict graph and local graph at every device. Simulation results show that our coding scheme significantly reduces the number of transmission slots, which will increase the efficiency of video delivery.展开更多
阐述广播电视播出中的码流自适应调整技术的现状,介绍基于超文本传输协议(Hyper Text Transfer Protocol,HTTP)的动态自适应流媒体技术的广泛应用及优势。同时,分析高精度码流自适应调整技术面临的挑战,涵盖算法复杂度与实时性冲突、视...阐述广播电视播出中的码流自适应调整技术的现状,介绍基于超文本传输协议(Hyper Text Transfer Protocol,HTTP)的动态自适应流媒体技术的广泛应用及优势。同时,分析高精度码流自适应调整技术面临的挑战,涵盖算法复杂度与实时性冲突、视频编码技术局限性以及设备性能与兼容性问题,并提出相应的对策,旨在为高精度码流自适应调整技术的发展提供理论支持和实践指导。展开更多
背景与目的全胸腔镜肺段切除术随早期肺癌的高检出率逐渐受到关注,其中肺段切除术段间平面分离最常用的方法是电刀切割手工缝合和应用直线切割缝合器机械切割两种。但仅有很少的研究对两者进行对比,且均针对开放式肺段切除术,目前尚未...背景与目的全胸腔镜肺段切除术随早期肺癌的高检出率逐渐受到关注,其中肺段切除术段间平面分离最常用的方法是电刀切割手工缝合和应用直线切割缝合器机械切割两种。但仅有很少的研究对两者进行对比,且均针对开放式肺段切除术,目前尚未有相应的研究针对全胸腔镜肺段切除术。本研究旨在探讨两种方法在全胸腔镜手术中的应用及安全性对比。方法回顾性分析2013年9月-2016年3月北京大学第一医院胸外科行全胸腔镜肺段切除术的连续58例患者,根据段间平面分离方法不同分为电刀切割组30例和机械切割组28例,对两组患者手术时间、出血量、术后胸管留置时间、术后住院时间、胸腔引流量及术后并发症进行比较。结果除手术时间[电刀切割组(248.70±54.46)min和机械切割组(209.39±67.25)min]两组间有统计学差异(P=0.017)外,术中出血量(60.00mL vs 65.00 mL)、胸腔引流总量(445.00 mL vs 590.00 mL)、术后3天胸腔引流量[(455.33±318.333)mL vs(422.32±194.95)mL]、术后胸管留置时间(3.50天vs 4.00天)和术后住院时间(6.00天vs 6.00天)、术后并发症发生率(5/30vs 2/28),两组差异均无统计学意义。结论全胸腔镜肺段切除术段间平面的分离方法中,应用电刀切割手工缝合手术时间相对较长,但安全性不劣于应用切割缝合器机械切割缝合。展开更多
文摘Left ventricular assist devices(LVAD)are increasingly become common as life prolonging therapy in patients with advanced heart failure.Current devices are now used as definitive treatment in some patients given the improved durability of continuous flow pumps.Unfortunately,continuous flow LVADs are fraught with complications such as gastrointestinal(GI)bleeding that are primarily attributed to the formation of arteriovenous malformations.With frequent GI bleeding,antiplatelet and anticoagulation therapies are usually discontinued increasing the risk of life-threatening events.Small bowel bleeds account for 15%as the source and patients often undergo multiple endoscopic procedures.Treatment strategies include resuscitative measures and endoscopic therapies.Medical treatment is with octreotide.Novel treatment options include thalidomide,angiotensin converting enzyme inhibitors/angiotensinⅡreceptor blockers,estrogen-based hormonal therapies,doxycycline,desmopressin and bevacizumab.Current research has explored the mechanism of frequent GI bleeds in this population,including destruction of von Willebrand factor,upregulation of tissue factor,vascular endothelial growth factor,tumor necrosis factor-α,tumor growth factor-β,and angiopoetin-2,and downregulation of angiopoetin-1.In addition,healthcare resource utilization is only increasing in this patient population with higher admissions,readmissions,blood product utilization,and endoscopy.While some of the novel endoscopic and medical therapies for LVAD bleeds are still in their development stages,these tools will yet be crucial as the number of LVAD placements will likely only increase in the coming years.
基金supported by Fundamental Research Funds for the Central Universities(No.SWU115002,No.XDJK2015C104)
文摘The increasing popularity of smart mobile devices and the rise of online services has increased the requirements for efficient dissemination of social video contents. In this paper,we study the problem of distributing video from cloud server to users in partially connected cooperative D2 D network using network coding. In such a scenario, the transmission conflicts occur from simultaneous transmissions of multiple devices, and the scheduling decision should be made not only on the encoded packets but also on the set of transmitting devices. We analyze the lower bound and give an integer linear formulation of the joint optimization problem over the set of transmitting devices and the packet combinations.We also propose a heuristic solution for this setup using a conflict graph and local graph at every device. Simulation results show that our coding scheme significantly reduces the number of transmission slots, which will increase the efficiency of video delivery.
文摘阐述广播电视播出中的码流自适应调整技术的现状,介绍基于超文本传输协议(Hyper Text Transfer Protocol,HTTP)的动态自适应流媒体技术的广泛应用及优势。同时,分析高精度码流自适应调整技术面临的挑战,涵盖算法复杂度与实时性冲突、视频编码技术局限性以及设备性能与兼容性问题,并提出相应的对策,旨在为高精度码流自适应调整技术的发展提供理论支持和实践指导。
文摘背景与目的全胸腔镜肺段切除术随早期肺癌的高检出率逐渐受到关注,其中肺段切除术段间平面分离最常用的方法是电刀切割手工缝合和应用直线切割缝合器机械切割两种。但仅有很少的研究对两者进行对比,且均针对开放式肺段切除术,目前尚未有相应的研究针对全胸腔镜肺段切除术。本研究旨在探讨两种方法在全胸腔镜手术中的应用及安全性对比。方法回顾性分析2013年9月-2016年3月北京大学第一医院胸外科行全胸腔镜肺段切除术的连续58例患者,根据段间平面分离方法不同分为电刀切割组30例和机械切割组28例,对两组患者手术时间、出血量、术后胸管留置时间、术后住院时间、胸腔引流量及术后并发症进行比较。结果除手术时间[电刀切割组(248.70±54.46)min和机械切割组(209.39±67.25)min]两组间有统计学差异(P=0.017)外,术中出血量(60.00mL vs 65.00 mL)、胸腔引流总量(445.00 mL vs 590.00 mL)、术后3天胸腔引流量[(455.33±318.333)mL vs(422.32±194.95)mL]、术后胸管留置时间(3.50天vs 4.00天)和术后住院时间(6.00天vs 6.00天)、术后并发症发生率(5/30vs 2/28),两组差异均无统计学意义。结论全胸腔镜肺段切除术段间平面的分离方法中,应用电刀切割手工缝合手术时间相对较长,但安全性不劣于应用切割缝合器机械切割缝合。
