采用IEEE(institute of electrical and electronics engineers,美国电气和电子工程师协会)提供的公式对河池市2010年1月—2017年12月的闪电数据进行雷电流累积频率拟合,结合电气-几何模型(EGM)建立了与建筑物、接闪器特性参数有关的雷...采用IEEE(institute of electrical and electronics engineers,美国电气和电子工程师协会)提供的公式对河池市2010年1月—2017年12月的闪电数据进行雷电流累积频率拟合,结合电气-几何模型(EGM)建立了与建筑物、接闪器特性参数有关的雷击建筑物物理损害概率(PB)计算公式,将此公式用于计算建筑物PB值,结果比国际电工委员会提出的评估标准IEC 62305推荐的参考值更具准确性。利用该方法对河池市PB进行了区划,为防雷技术评价提供了可靠参考。展开更多
在全光网络中,不同的物理损害如光纤非线性效应等可在光传输系统中发生,同一节点到控制中心的不同光通路的性能也存在区别,物理损害和链路性能波动会在光通路上累积并造成严重的信号衰减.在路由和波长分配算法的设计中需要考虑这些物理...在全光网络中,不同的物理损害如光纤非线性效应等可在光传输系统中发生,同一节点到控制中心的不同光通路的性能也存在区别,物理损害和链路性能波动会在光通路上累积并造成严重的信号衰减.在路由和波长分配算法的设计中需要考虑这些物理损害、性能波动和衰减,以提供服务质量（quality of service,QoS）感知的服务.软件定义网（Software－defined networking,SDN）被认为是下一代控制和管理框架,控制平面和数据平面的分离大大促进了网络可编程性,基于软件定义的光传输网络（Software－defined optical transport network,SD－OTN）,可以灵活设计QoS感知的路由算法.本文于SD－OTN设计了一种QoS感知算法,根据实时的物理损害和链路性能波动情况对路由进行及时调整,以实现阻塞概率降低近30%和频谱消耗降低近20%,全网性能得以更优化.展开更多
After peripheral nerve injury, intraperitoneal injection of folic acid improves axon quantity, increases axon density and improves electromyography results. However, the mechanisms for this remain unclear. This study ...After peripheral nerve injury, intraperitoneal injection of folic acid improves axon quantity, increases axon density and improves electromyography results. However, the mechanisms for this remain unclear. This study explored whether folic acid promotes peripheral nerve injury repair by affecting Schwann cell function. Primary Schwann cells were obtained from rats by in vitro separation and culture. Cell proliferation, assayed using the Cell Counting Kit-8 assay, was higher in cells cultured for 72 hours with 100 mg/L folic acid compared with the control group. Cell proliferation was also higher in the 50, 100, 150, and 200 mg/L folic acid groups compared with the control group after culture for 96 hours. Proliferation was markedly higher in the 100 mg/L folic acid group compared with the 50 mg/L folic acid group and the 40 ng/L nerve growth factor group. In Transwell assays, the number of migrated Schwann cells dramatically increased after culture with 100 and 150 mg/L folic acid compared with the control group. In nerve growth factor enzyme-linked immunosorbent assays, treatment of Schwa nn cell cultures with 50, 100, and 150 mg/L folic acid increased levels of nerve growth factor in the culture medium compared with the control group at 3 days. The nerve growth factor concentration of Schwann cell cultures treated with 100 mg/L folic acid group was remarkably higher than that in the 50 and 150 mg/L folic acid groups at 3 days. Nerve growth factor concentration in the 10, 50, and 100 mg/L folic acid groups was higher than that in the control group at 7 days. The nerve growth factor concentration in the 50 mg/L folic acid group was remarkably higher than that in the 10 and 100 mg/L folic acid groups at 7 days. In vivo, 80 μg/kg folic acid was intraperitoneally administrated for 7 consecutive days after sciatic nerve injury. Immunohistochemical staining showed that the number of Schwann cells in the folic acid group was greater than that in the control group. We suggest that folic acid may play a role in improving the repair of peripheral nerve injury by promoting the proliferation and migration of Schwann cells and the secretion of nerve growth factors.展开更多
Peripheral nerve injury is a common clinical problem and affects the quality of life of patients. Traditional restoration methods are not satisfactory. Researchers increasingly focus on the field of tissue engineering...Peripheral nerve injury is a common clinical problem and affects the quality of life of patients. Traditional restoration methods are not satisfactory. Researchers increasingly focus on the field of tissue engineering. The three key points in establishing a tissue engineering material are the biological scaffold material, the seed cells and various growth factors. Understanding the type of nerve injury, the construction of scaffold and the process of repair are necessary to solve peripheral nerve injury and promote its regeneration. This review describes the categories of peripheral nerve injury, fundamental research of peripheral nervous tissue engineering and clinical research on peripheral nerve scaffold material, and paves a way for related research and the use of conduits in clinical practice.展开更多
Hamstring strain injuries are common among sports that involve sprinting,kicking,and high-speed skilled movements or extensive muscle lengthening-type maneuvers with hip flexion and knee extension.These injuries prese...Hamstring strain injuries are common among sports that involve sprinting,kicking,and high-speed skilled movements or extensive muscle lengthening-type maneuvers with hip flexion and knee extension.These injuries present the challenge of significant recovery time and a lengthy period of increased susceptibility for recurrent injury.Nearly one third of hamstring strains recur within the first year following return to sport with subsequent injuries often being more severe than the original.This high re-injury rate suggests that athletes may be returning to sport prematurely due to inadequate return to sport criteria.In this review article,we describe the epidemiology,risk factors,differential diagnosis,and prognosis of an acute hamstring strain.Based on the current available evidence,we then propose a clinical guide for the rehabilitation of acute hamstring strains and an algorithm to assist clinicians in the decision-making process when assessing readiness of an athlete to return to sport.展开更多
The principles of open fracture management are to manage the overall injury and specifically prevent primary contamination becoming frank infection. The surgical management of these complex injuries includes debrideme...The principles of open fracture management are to manage the overall injury and specifically prevent primary contamination becoming frank infection. The surgical management of these complex injuries includes debridement ＆ lavage of the open wound with combined bony and soft tissue reconstruction. Good results depend on early high quality definitive surgery usually with early stable internal fixation and associated soft tissue repair. While all elements of the surgical principles are very important and depend on each other for overall success the most critical element appears to be achieving very early healthy soft tissue cover. As the injuries become more complex this involves progressively more complex soft tissue reconstruction and may even requiring urgent free tissue transfer requiring close co-operative care between orthopaedic and plastic surgeons. Data suggests that the best results are obtained when the whole surgical reconstruction is completed within 48-72 h.展开更多
文摘采用IEEE(institute of electrical and electronics engineers,美国电气和电子工程师协会)提供的公式对河池市2010年1月—2017年12月的闪电数据进行雷电流累积频率拟合,结合电气-几何模型(EGM)建立了与建筑物、接闪器特性参数有关的雷击建筑物物理损害概率(PB)计算公式,将此公式用于计算建筑物PB值,结果比国际电工委员会提出的评估标准IEC 62305推荐的参考值更具准确性。利用该方法对河池市PB进行了区划,为防雷技术评价提供了可靠参考。
文摘在全光网络中,不同的物理损害如光纤非线性效应等可在光传输系统中发生,同一节点到控制中心的不同光通路的性能也存在区别,物理损害和链路性能波动会在光通路上累积并造成严重的信号衰减.在路由和波长分配算法的设计中需要考虑这些物理损害、性能波动和衰减,以提供服务质量（quality of service,QoS）感知的服务.软件定义网（Software－defined networking,SDN）被认为是下一代控制和管理框架,控制平面和数据平面的分离大大促进了网络可编程性,基于软件定义的光传输网络（Software－defined optical transport network,SD－OTN）,可以灵活设计QoS感知的路由算法.本文于SD－OTN设计了一种QoS感知算法,根据实时的物理损害和链路性能波动情况对路由进行及时调整,以实现阻塞概率降低近30%和频谱消耗降低近20%,全网性能得以更优化.
基金supported by the High Levels of Health Technical Personnel in Beijing City Health System of China,No.2013-3-050(to JZY)
文摘After peripheral nerve injury, intraperitoneal injection of folic acid improves axon quantity, increases axon density and improves electromyography results. However, the mechanisms for this remain unclear. This study explored whether folic acid promotes peripheral nerve injury repair by affecting Schwann cell function. Primary Schwann cells were obtained from rats by in vitro separation and culture. Cell proliferation, assayed using the Cell Counting Kit-8 assay, was higher in cells cultured for 72 hours with 100 mg/L folic acid compared with the control group. Cell proliferation was also higher in the 50, 100, 150, and 200 mg/L folic acid groups compared with the control group after culture for 96 hours. Proliferation was markedly higher in the 100 mg/L folic acid group compared with the 50 mg/L folic acid group and the 40 ng/L nerve growth factor group. In Transwell assays, the number of migrated Schwann cells dramatically increased after culture with 100 and 150 mg/L folic acid compared with the control group. In nerve growth factor enzyme-linked immunosorbent assays, treatment of Schwa nn cell cultures with 50, 100, and 150 mg/L folic acid increased levels of nerve growth factor in the culture medium compared with the control group at 3 days. The nerve growth factor concentration of Schwann cell cultures treated with 100 mg/L folic acid group was remarkably higher than that in the 50 and 150 mg/L folic acid groups at 3 days. Nerve growth factor concentration in the 10, 50, and 100 mg/L folic acid groups was higher than that in the control group at 7 days. The nerve growth factor concentration in the 50 mg/L folic acid group was remarkably higher than that in the 10 and 100 mg/L folic acid groups at 7 days. In vivo, 80 μg/kg folic acid was intraperitoneally administrated for 7 consecutive days after sciatic nerve injury. Immunohistochemical staining showed that the number of Schwann cells in the folic acid group was greater than that in the control group. We suggest that folic acid may play a role in improving the repair of peripheral nerve injury by promoting the proliferation and migration of Schwann cells and the secretion of nerve growth factors.
基金supported by the National Natural Science Foundation of China,No.31040043,31671248(to NH),No.81171146,81372044,30971526(to BGJ)the Chinese National Ministry of Science and Technology(973 Project),No.2014CB542201(to PXZ)+4 种基金the Ministry of Education Innovation Team,China,No.IRT1201(to PXZ)the Fostering Young Scholars of Peking University Health Science Center,China,No.BMU2017PY013(to PXZ)the Chinese National General Program of National Natural Science Fund,China(to PXZ)the Beijing City Science&Technology New Star Cross Project,China,No.2018019(to PXZ)the National Natural Science Foundation of China,No.31771322,31571235,51373023,21171019,31640045,31571236,31471144,31100860,31371210(to PXZ)
文摘Peripheral nerve injury is a common clinical problem and affects the quality of life of patients. Traditional restoration methods are not satisfactory. Researchers increasingly focus on the field of tissue engineering. The three key points in establishing a tissue engineering material are the biological scaffold material, the seed cells and various growth factors. Understanding the type of nerve injury, the construction of scaffold and the process of repair are necessary to solve peripheral nerve injury and promote its regeneration. This review describes the categories of peripheral nerve injury, fundamental research of peripheral nervous tissue engineering and clinical research on peripheral nerve scaffold material, and paves a way for related research and the use of conduits in clinical practice.
文摘Hamstring strain injuries are common among sports that involve sprinting,kicking,and high-speed skilled movements or extensive muscle lengthening-type maneuvers with hip flexion and knee extension.These injuries present the challenge of significant recovery time and a lengthy period of increased susceptibility for recurrent injury.Nearly one third of hamstring strains recur within the first year following return to sport with subsequent injuries often being more severe than the original.This high re-injury rate suggests that athletes may be returning to sport prematurely due to inadequate return to sport criteria.In this review article,we describe the epidemiology,risk factors,differential diagnosis,and prognosis of an acute hamstring strain.Based on the current available evidence,we then propose a clinical guide for the rehabilitation of acute hamstring strains and an algorithm to assist clinicians in the decision-making process when assessing readiness of an athlete to return to sport.
文摘The principles of open fracture management are to manage the overall injury and specifically prevent primary contamination becoming frank infection. The surgical management of these complex injuries includes debridement ＆ lavage of the open wound with combined bony and soft tissue reconstruction. Good results depend on early high quality definitive surgery usually with early stable internal fixation and associated soft tissue repair. While all elements of the surgical principles are very important and depend on each other for overall success the most critical element appears to be achieving very early healthy soft tissue cover. As the injuries become more complex this involves progressively more complex soft tissue reconstruction and may even requiring urgent free tissue transfer requiring close co-operative care between orthopaedic and plastic surgeons. Data suggests that the best results are obtained when the whole surgical reconstruction is completed within 48-72 h.
