Identification and culture of neural stem cells isolated from adult rat subventricular zone following fluid percussion brain injury

Objective To analyze proliferation and differentiation of glial fibrillary acid protein (GFAP)- and nestin-positive (GFAP+/nestin+) cells isolated from the subventricular zone following fluid percussion brain injury to determine whether GFAP+/nestin+ cells exhibit characteristics of neural stem cells. Methods Male Sprague-Dawley rats, aged 12 weeks and weighing 200-250 g, were randomly and evenly assigned to normal control group and model group. In the model group, a rat model of fluid percussion brain injury was established. Five days later, subventricular zone tissue was resected from each group and made into single cell suspension. After serum-free neural stem cell medium culture and subsequent serum-induced differentiation, cell type, proliferation and differentiation capacities were determined by immunofluorescence staining and flow cytometry. Results At 3-7 days after fluid percussion brain injury, nestin+/GFAP+ cells in the single cell suspension from the model group significantly outnumbered those from the normal control group (P<0.01). In the model group, an increased number of small neurospheres with smooth cell edge and bulged center formed after primary culture, and were clearly visible with the increase of culture time and medium replacement. After several passages, many clonal spheres were obtained, suggesting strong self-proliferatiing capacity. Neurospheres from the model group differentiated into astrocytes, neurons and oligodendrocytes. Conclusion GFAP+/nestin+ cells isolated from the adult rat subventricular zone after fluid percussion brain injury are thought to be neural stem cells because of their self-renewal and multi-differentiation capacities.     

对LJ-60型拦和机石料烘干系统的分析与改进设计

通过对现行LJ-60型拌和机石料烘干系统的分析，结合设备的具体情况，提出了改进设计方案，并介绍了实施办法和系统功能。     

关于延长油漆涂层使用周期及清洗剂的研究(下)

車辆的清洗剂問題 一、关于清洗問題 車辆在运行时很易污损,所以在客車段与电車段內均对車辆进行定期清洗。若用溶解方法去除車辆表面的铁质类等污物时,所使用的清洗剂是以无机酸为主的酸性清洗剂,这也是造成車辆漆膜劣化及变色的主要原因。因此,为了使油漆的涂层使用     

沥青与石料间的剪切粘附性研究

利用自己开发设计的剪切粘附试验，对两种品质的沥青和两种性质的石料进行了粘附性剪切试验分析，给出了沥青与石料间粘附性强弱的定量评价方法及其受剪切速率和试验温度影响的变化规律。     

LS—1型抗剥离剂的研制及在道路工程中的应用

本文从分析酸性石料与沥青裹不好的机理入手，研制出适于酸性石料的沥青抗剥离剂，填补了本省无抗剥离剂的空白，具有较好的经济效益和社会效益。     

振动压实过程中填石料破碎分形机制研究

填石料大量应用于山区高速公路建设中,通过进行填石料现场振动压实试验的基础上,取得了填石料在振动压实过程中颗粒级配的数据和填石层的压缩沉降量。通过引入分形理论对填石料的颗粒级配数据进行分析,发现采用分形理论可以合理的描述填石料在振动压实过程中颗粒破碎的特征。采用分形粒子模型对不同压实遍数下填石料的级配数据的计算结果表明,随着压实的进行,填石料的颗粒结构逐步向分形结构转化,这表明填石料的振动压实过程是一个向稳定结构转化的过程。在这个转化过程中,填石料的分数维逐渐增大并趋于稳定临界值,该临界值对工程具有指导意义。     

解决石料在称量过程中落差大的方法

LQB— 12 0 0型沥青混合料拌和机的规格料 (热料 )称量过程如图 1所示 :在计量斗的规格料达到电子秤上设定的质量后 ,电子秤迅速给出信号通过中间继电器、电磁控制阀控制气缸动作关闭仓门。显然此时计量斗中的规格料达到电子秤上规定的质量 ,但仍有质量为 m=Ahρ的石料悬在空中 ,电子秤没有称量到其质量。其中 ,A为热料仓门的面积 ;h为料的高度 ;ρ为石料的密度。因此 ,实际落到计量斗中的该种料的质量为 M′=M(电子秤上设定 ) m。显然 M′>M,则 m被定义为落差。由公式 m=Ahρ可知m的小大和 A的大小有关。经过实地观察决定把原来的单…     

土工格栅加固大坝及其加筋结构性能的有限元分析

针对某大坝在加高工程中当地填料短缺、土石料运距远、单价高等技术经济问题,在大坝加高工程中引入双面板格栅加筋挡墙结构,并对加筋挡土墙结构进行有限元分析计算。计算结果与实测结果相当吻合。施工实测及计算表明,双面板格栅加筋挡土墙能有效地控制顶部的变形,结构安全可靠,整体效果良好,对土工格栅在筑坝工程中的应用有重要参考意义。     

麻黄碱对脑缺血再灌注损伤大鼠脑内星形胶质细胞GFAP表达的影响

目的探讨大鼠脑缺血再灌注损伤后麻黄碱治疗对星形胶质细胞胶质原纤维酸性蛋白(GFAP)表达水平的影响。方法雄性SD大鼠60只,随机分为假手术组、自然恢复组和治疗组。应用线栓法建立单侧大脑中动脉缺血再灌注模型,术后1、2、3、4周应用免疫组化观察缺血周围区GFAP的表达。结果自然恢复组和治疗组术后1周GFAP表达开始增加,3周后表达平稳。治疗组GFAP的表达水平在前两个时间点高于自然恢复组(P<0.05)。结论麻黄碱对脑缺血再灌注损伤大鼠缺血周围区星形胶质细胞增殖活化有促进作用。