大鼠坐骨神经再生过程中的神经元轴突自噬作用

目的：探讨大鼠坐骨神经变性轴突清除中的自噬作用。方法：横切大鼠坐骨神经制作wallerian变性模型,造模后不同时间点取远断端组织行电镜结构观察和酸性磷酸酶(AcPase)活性检测。结果：坐骨神经横切后轴突发生变性,主要变化为术后第5h～2d轴质肿胀,轴突与髓鞘分离,术后第4d轴质浓缩,轴突与髓鞘完全分离形成游离轴突体。术后初期变性轴突主要形成大小不等的空泡,后期轴突与髓鞘完全分离并形成较大的游离轴突体,轴突体外包一层轴突膜是神经元细胞膜的延续,轴突体轴质浓缩,含大量各级自噬泡和纵横交错的神经丝、微管和微丝。经酸性磷酸酶(AcPase)染色证实自噬泡均呈AcPase阳性,第7d后轴突体被降解吸收,形成的空腔内偶见巨噬细胞。结论：大鼠坐骨神经再生过程中变性轴突的清除主要靠轴突自身的自噬和施万细胞吞噬机制,而巨噬细胞只起辅助作用。     

基于STM32的分布式步进电机控制系统设计

针对多步进电机控制系统的要求,设计了基于STM32及MSP430的分布式多步进电机控制系统,采用了USB及CAN的通信方式。文中详细阐述了系统的总线拓扑结构、软硬件设计、USB驱动程序设计及步进电机加减速特性的设计,实现了对多个步进电机的分布式控制。     

自体腱形成中的胶原原纤维的形成与降解

随着我国工业化进程的加速、交通、工伤事故发生率也随之增加，在四肢损伤外科中，肌腱损伤占有一定比例，采用替代物修复受损组织的各种方法都具有不同程度的弊端，如异体腱具有不同程度的排斥反应，自体腱则取材受限难以推广，而人工合成材料也存在组织相容性等问题，近10年来，本课题组成功地研制出人发角蛋白（HHK）人工腱，通过临床试验证实该人工腱能够诱导自体腱的形成，并对其机理进行了探讨。     

Single-polarization single-mode hollow-core negative curvature fiber with nested U-type cladding elements

Hollow-core negative curvature fibers (HC-NCFs) have become one of the research hotspots in the field of optical fiber because of their potential applications in the data and energy transmissions. In this work, a new kind of single-polarization single-mode HC-NCF with nested U-type cladding elements is proposed. To achieve the single-polarization single-mode transmission, we use two different silica tubes in thickness, which satisfy the resonance and anti-resonance conditions on the U-type cladding elements and the cladding tubes, respectively. Besides, the elliptical elements are introduced to achieve good single-mode performance. By studying the influences of the structure parameters on the propagation characteristics, the optimized structure parameters are obtained. The simulation results show that when the wavelength is fixed at 1550 nm, the single-polarization single-mode transmission is achieved, with the polarization extinction ratio of 25749 and minimum high-order mode extinction ratio of 174. Furthermore, the confinement loss is only 0.0015 dB/m.