城市浅埋隧道施工对地面房屋影响的数值计算

随着城市隧道的修建,浅埋隧道穿越房屋的数量明显增多.应用三维有限元计算地面房屋横跨凹凸区的工况,得出了房屋不同区域部分与不同方向的变形规律,为隧道接近建筑物施工提供了参考价值.     

葛根中有效部位及有效成分的高效液相色谱分析

目的建立全面控制葛根及其制剂的定性和定量分析方法。方法用反相高效液相色谱法(RPHPLC),以甲醇水(42∶58)为流动相在250nm波长下检测,对葛根有效部位(醋酸乙酯提取部位)进行指纹图谱定性分析,对葛根有效部位中的有效成分葛根素和大豆苷元进行定量测定,并对11种不同来源的葛根药材进行分析测定。结果在定性分析条件下,葛根有效部位的HPLC指纹图谱中有5个共有峰,可以作为其定性鉴别的指标峰;在以葛根素和大豆苷元为定量指标分析中,其方法的回收率分别为98.0%和95.4%,相对标准偏差(RSD)分别为1.30%和1.61%,葛根药材中葛根素和大豆苷元的含量分别在0.213%～3.626%和0.012%～0.049%范围内。结论以葛根有效部位指纹图谱定性分析和有效成分定量分析方法,可以准确有效地控制其质量。     

从词汇层面上看语言教学中的文化输入

本从化与语言的关系谈起，说明化输入在语言教学中的重要性。然后以汉英词汇的含义、范围异同来着重谈词汇层面上的化内涵，指出在教授词汇时化因素不可疏忽，提出以新角度看待化教学，提倡词汇层面上的化输入。     

西安汉族人群HLA-DQA1基因座遗传多态性研究

目的　了解西安汉族群体HLA DQA1基因座的基因及基因型分布 ,获得西安汉族群体HLA DQA1群体遗传学数据。方法　采用PERKIN ELMER公司生产的AmpliTypePM试剂盒 ,PCR扩增HLA DQA1基因座 ,与 11个寡核苷酸探针杂交 ,对西安地区汉族 10 2名无关个体HLA DQA1基因座进行基因频率调查。结果　检出 7种等位基因、2 8种基因型 ,经 χ2 检验基因型的观察值与期望值符合Hardy Weinberg平衡定律 (P >0 .5 ) ,其杂合度 (H)、个体识别率 (DP)、非父排除率 (EPP)和多态信息量 (PIC)分别为 0 .8317、0 .9393、0 .786 6和0 .82 5 0。结论　所得到的群体遗传学数据为遗传学、法医学个体识别和亲权鉴定提供依据     

长安县农村中小学生视力10年监测结果分析

目的　研究农村中小学生 10年的视力变化规律 ,为更好地开展学校视力保护工作提供依据。方法　按照国家统一的学生视力检测方法和要求 ,对长安县中小学生 1990～ 1999年视力进行检测 ,对视力均值及视力低下率分别进行统计分析。结果　 10年间男、女学生双眼视力均值均在 5 .0以上 ,视力低下率为 5 .0 %～ 8.3%。男生的视力均值高于女生 ,视力低下率低于女生。视力低下率随学习阶段的上升而上升 ,以小学至初中阶段增幅最大 ,各学习阶段均以轻、中度视力低下为主 ,重度视力低下率随学习阶段上升增长幅度最大。学生左、右眼视力无明显差异。结论　 10年来长安县农村学生的视力发育状况总体上是良好的 ,但视力低下率随学习阶段增长速度加快。建议 :对学生视力低下的预防应从小学阶段开始 ,尤其要重视小学升初中学习阶段的预防工作 ,同时要防止视力低下程度在初中及高中学习阶段加深     

现代汽车电子巡航控制

汽车电子巡航控制系统,简称CCS,根据其特点一般又称为"巡航行驶装置"、"速度控制系统"、"自动驾驶系统"等.     

临时对象内存管理算法的研究

传统的内存管理方式在分配与释放临时对象的内存时存在一些局限。本文提出了一种新的应用于临时对象的内存管理算法，该算法内存分配和释放的速度都很快。时间需求十分固定，同时还避免了内存碎片的产生。     

基于效益机制的分局调度货运日计划优化模型

在效益机制下进行货运日计划优化的目的是，在有限的运输资源条件下，使日计划实现运输效益最大化．在分析车站能力、空车供应、限制口能力和分界口交接等诸多运输约束的基础上，通过对运输约束准确的数学描述，建立了以运输效益最大为目标函数、以运输限制为约束的优化模型。     

The β-amyloid protein induces S100β expression in rat hippocampus through a mechanism that involves IL-1

Objective To explore the effect of β-amyloid protein (Aβ) on S100β expression in rat hippocampus and its mechanisms. Methods At 7 days after bilateral stereotaxis injection of different dose of fibrillar Aβ 25-35 and interluekin-1 receptor antagonist (IL-1ra) into the rat CA1 region, the learning and memory abilities of rats were tested with passive avoidance task. Amyloid deposition was detected by using Congo red staining technique. Nissl staining and immunohistochemical techniques were used to analyze the number of neurons, and GFAP and the S100β expression in hippocampal CA1 region , respectively. Results After fibrillar Aβ injection, the step-through latency of rats was significantly shortened compared to that of the control group. The GFAP positive astrocytes were found surrounding amyloid deposition. Neuronal loss occurred in the pyramidal cell layer of CA1 region. The number of S100β positive cells in Aβ-treated group was significantly increased compared with that in the control group. After IL-1ra injection, the number of S100β positive cells was significantly decreased. Conclusion Intrahippocampal injection of Aβ 25-35 could cause similar pathologic changes of Alzheimer's disease. Aβ 25-35 was capable of up-regulating S100β expression in a dose-dependent manner. The injection of IL-1ra could attenuate the effect of Aβ on S100β expression.     

PROLIFERATION AND MIGRATION OF EPENDYMAL CELLS IN THE BRAIN OF ADULT RATS AFTER PERMANENT FOCAL CEREBRAL ISCHEMIA

Objective Ependymal cells are thought to be the primary source of neural stem cells in the adult central nervous system. The purpose of this study is to examine spatial and temporal profiles of ependymal cell proliferation and migration after focal cerebral ischemia. Methods Eighty male Sprague Dawley rats underwent permanent middle cerebral artery occlusion after injection of 10/μL of 0.2% Dil into the lateral ventricle. Rats were sacrificed and brain sections were acquired for pathological evaluation and laser confocal imaging at day 1,3,7,11,14,21 and 28 after ischemia. Results The density of Dil-labeled cells in the ischemic ipsilateral subventricular zone was significantly higher than that in the control group and these labeled cells dispersed in the ischemic ipsilateral subventricular zone and/or were located in ependyma from day 1 to 11. In the ischemic ipsilateral cortex, some Diilabeled cells occurred in peri-infarction and infarction of parietal region at day14 and peaked at day 21 when some Dil-labeled cell nodules were found in this region. During postischemic day 14--28, a significant decrease in labeled celldensity in the ischemic ipsilateral subventricular zone was coincident with a significant increase in labeled cells density in the cortex (peri-infarction and infarction). Conclusion The results indicate that ependymal cells proliferate and migrate after focal cerebral ischemia in the adult rat brain.