血管活性肠肽对暂时性脑缺血大鼠梗死体积的影响

目的通过活体实验研究血管活性肠肽(VIP)对脑缺血损伤的神经保护作用。方法大鼠侧脑室内注射VIP后,采用大脑中动脉线栓(MCAO)法诱导建立暂时性局部脑缺血模型。通过神经学的评价对MCAO大鼠进行判定和筛选;TTC染色测定大鼠脑梗死体积;双抗夹心ELISA检测血清S100β的含量。结果MCAO后2 h大鼠呈现不同程度的神经功能损伤症状。评定为1-2级的仅有2例出现明显脑梗死区,3级的为全部。VIP注射后大鼠脑梗死体积明显缩小,较对照组减少约25%(P<0.05);血清S100β浓度也明显降低(P<0.05)。结论以神经学评分3级作为MCAO模型成功的判定标准是较为可靠的。VIP脑内注射可明显减小脑缺血后梗死体积,具有神经保护作用。VIP可以降低S100β的含量,这可能涉及到VIP的另一神经保护机制。     

平阳霉素局部注射对鼻息肉病息肉组织病理学的影响

目的通过观察平阳霉素治疗前后鼻息肉病息肉组织的病理变化情况,探讨平阳霉素治疗鼻息肉病的机制。方法应用末端脱氧核苷酸转移酶介导的脱氧三磷酸尿苷缺口末端标记法(TUNEL法)检测凋亡细胞,与相邻连续的HE染色片对位对照观察嗜酸性粒细胞的凋亡情况。结果平阳霉素治疗前鼻息肉组织嗜酸性粒细胞表达显著高于正常下鼻甲(P<0.01);治疗后鼻息肉组织中的嗜酸性粒细胞表达明显低于治疗前(P<0.01);治疗后鼻息肉组织中嗜酸性粒细胞的凋亡指数高于治疗前(P<0.01)。结论嗜酸性粒细胞是鼻息肉病息肉组织中主要的浸润炎细胞;平阳霉素可通过促进嗜酸性粒细胞凋亡达到治疗鼻息肉病的目的。     

应用激光捕获显微切割技术制备肺癌蛋白质组学研究样品

目的探讨应用激光捕获显微切割(laser capture microdissection,LCM)技术获取高同质性肺癌组织细胞及正常对照肺泡上皮细胞的方法及可行性。方法将新鲜肺癌组织标本及其配对正常组织常规制备8μm冰冻切片,采用改良的HE方法染色;应用LCM技术大宗切割肺鳞癌、腺癌及正常对照肺泡上皮细胞;选择性获取同质肺癌细胞和配对正常细胞。结果通过LCM技术可以准确、快速地分离癌细胞、间质及其他坏死组织,得到同质性不低于95%的肿瘤细胞和正常细胞。按照Duration 15.5 s的激光脉冲频率和平均8 000 shots条件,既可保证每个帽子的细胞收集数量,也能够有效地缩短实验时间,提高实验可控性,从而使操作过程标准化。结论应用LCM技术可以成功获取同质肺癌细胞和正常细胞。其所需标本量少、组织同质性高、操作过程稳定、可控性好,是肺癌分子生物学及蛋白质组学研究有价值的样品制备方法。     

42 V电控发动机冷却系统的研究

冷却系统是发动机的重要组成部分,分析了传统冷却系统的不足,设计基于模糊控制的42V发动机电子控制冷却系统,该冷却系统能够实现散热风扇的无级变速,使发动机工作在最佳温度,使之更经济、更环保,给出了模糊控制器的仿真结果,对比试验结果显示较传统冷却系统性能优越。     

西安快速公交建设模式研究

针对快速公交这种"现代化、高等级、低费用、大容量"交通系统的特点,提出了在西安市的东西轴线玉祥门至朝阳门的主干路实施快速公交系统的具体构想,以及公交专用道的布设方案.最后阐述了布设站台方式以及与北大街十字相适应的站台模式.     

浅基桥梁水毁压浆加固探讨

结合山东省枣庄市省道干线公路新(泰)-枣(庄)公路小北庄桥的加固工程,介绍了运用压浆技术加固桥梁基础的设施工艺、注意事项,指出运用压浆技术可以使桥梁在短时间内恢复承载能力,具有良好的经济效益。     

高填方路堤沉降变形离心模型试验研究

通过离心模型试验,研究了高填方路堤在不同设计干密度和含水量条件下的沉降变形特征,沉降变形与填筑体的干密度和含水量之间的关系,以及在相同干密度、相同含水量条件下,填土的不同粒径含量配比对路基沉降变形的影响。研究结果表明：路堤垂直沉降的总体趋势随深度增加而递减;在含水量和干密度相同的条件下,路堤最大沉降值出现在P5（大于0.5mm的颗粒含量）达到65%左右。     

EB1基因表达与胚胎染色体数目异常的关系

目的研究EB1基因在胚胎绒毛细胞中的表达,并分析其对染色体分离的影响。方法采用荧光定量PCR技术检测EB1基因在人工流产绒毛核型分析正常的胚胎细胞和自然流产绒毛核型分析异常的胚胎细胞中的表达差异;免疫组织化学方法检测EB1蛋白在两者中的表达情况,并用Western blot加以验证。结果EB1基因mRNA拷贝数/GAPDH基因mRNA拷贝数的均值在人工流产绒毛核型分析正常的胚胎细胞中为0.010 04±0.008 223,在自然流产绒毛核型分析异常的胚胎细胞中为0.150 9±0.063 3。Western blot和免疫组织化学结果表明其在自然流产绒毛核型分析异常胚胎细胞中的表达也高于其在人工流产绒毛核型分析正常胚胎细胞中的表达。经统计分析,EB1基因mRNA水平和蛋白水平在上述两组细胞中的表达均有显著差异。结论EB1基因在自然流产绒毛核型分析异常的胚胎细胞中的表达明显高于其在人工流产绒毛核型分析正常的胚胎细胞中的表达,其高表达可能导致染色体分离异常。     

Study on lift-up speed of aerodynamic compliant foil thrust bearings

Objective The experimental study on the lift-up speed of a new kind of compliant aerodynamic foil thrust hearings was performed on the multifunetional test rig established for testing the performances of foil gas bearings. Methods The lift-up speed of foil gas thrust hearing under given axial load was analyzed through the spectrum of axial displacement response in frequency domain. Results The test results indicated that the difference in the spectrum of axial displacement responses before and after lifting up of the rotor was obvious. After lifting up of the rotor, there were only larger components of rotation frequency and lower harmanie frequencies. If the rotor wasn＇t lift-up, there were also larger components of other frequencies in the spectrum. Conclusion So by analyzing the spectrum of axial displacement response, the results showed that the lift-up speed was about 1 860 rpm when the axial load was 31N.     

Study of the mechanism on the apoptosis induced in Human leukemia cell line K562 by the combination of indole-3-acetic acid and horseradish peroxidase

Objective To investigate the mechanisms of apoptosis induced in Human leukemia cell line K562 by the combination of indole-3-acetic acid and horseradish peroxidase. Methods Human leukemia cell line K562 were exposed to indole-3-acetic acid （IAA） at 20, 40, 60, 80 or 100 mol/L and horseradish peroxidase（HRP） at 1.2 g/mL for varying times. MTT assay was applied to detect the cell proliferation. Flow cytometry was performed to detect the arrest of cell cycle. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） assay was used to measure apoptosis. 2, 7-dichlorofluorescin diacetate （DCFH-DA） uptake was measured to determine free radical by confocal microscope. Content of malondiadehyde （MDA） and activity of superoxide dismutase （SOD） were measured by biochemical methods. Results IAA/HRP initiated growth inhibition of K562 cells in a dose- and time-dependent manner. Flow cytometry revealed that cell cycle arrested at G1/G0 after 24 hours treatment. After 72 hours treatment, apoptotic rate of 100 mol/L IAA group increased to 43.9 %, which was 5 times that of control（P〈0.01）. Content of MDA and activity of SOD increased respectively in treatments compared with control. Meanwhile, IAA/HRP stimulated the formation of free radical, which was increased by IAA concentration-dependently. Conclusion The combination of IAAand HRP can inhibit the growth of Human leukemia cell line K562 in vitro by inducing apoptosis which is associated with the increase of free radical. The combination of IAA and HRP might be a promising chemopreventive and chemotherapeutic agent against human leukemia.