Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability were simulated. It shows that differential brake can amend turning shortage of automobile brake and improve its braking stability, but the effect of automobile mass on its braking stability is great. So the distribution mode of braking force and the effect of mass change should be considered while differential brake is applied.     

Role of candesartan against cerebral ischemia and oxidative damage in normotensive rats

Objective Angiotensin Ⅱ (Ang Ⅱ ) contributes to modulating blood pressure by stimulation of Ang Ⅱ AT1 receptors. We devised a rat transient middle cerebral artery occlusion (MCAO) model to assess whether oxidative damage is decreased after pretreatment with Angiotensin Ⅱ AT1 receptor blocker (ARB). Methods After 2 weeks pretreatment with ARB 0. 5 and 1 mg/kg, the male Wister rats were subjected to 2 h middle cerebral artery occlusion (MCAO). At 24 h, the lumen diameter of middle cerebral artery, the plasma level of 8-hydroxy-2'-deoxyguanosine (8-OHdG), and HIF-1 a levels were recorded and compared. Results After pretrcatment with ARB 0.5 and 1 mg/kg, blood pressure did not significantly change compared with that of controls. In the group of candesartan at 1 mg/(kg· day), the lumen diameter was significantly increased compared to that in control group [(86.0±5.0) μm vs. (69.0± 2.1) μm; P<0. 01, n = 6- 8]. The plasma 8-OHdG levels of ARB pretreatment groups were decreased. In immunohistochemical findings, 8-OHdG- and HIF-1α-containing cells in ARB pretreatment groups were decreased. Conclusion Brain ischemia and oxidative damage can be reversed by AT1 receptor blockade in normotensive rats after transient cerebral artery occlusion.     

The changes of neuronal activity of the zone incerta in a rodent model of Parkinson＇s disease

Objective To study the changes in neuronal activity of the zone incerta (ZI) following the unilateral lesion of the nigrostriatal pathway. Methods Eiectrophysiological recordings of ZI neurons were made in normal rats and in two groups of rats at different time intervals after injection of 6-hydrodopamine (6-OHDA) into the pars compacta of snbstantia nigra by extracellular recording in vivo. Results The results showed a significant increase in the mean firing rate of ZI during the second and fourth weeks after 6-OHDA lesion [-n=32, (3.6±2. 2)Hz, P<0.001; n=35, (9.3±6.6)Hz, P<0. 001, respectively] compared to that of normal rats [n=39, (9.2±5.2)Hz]. However, no significant change was observed between two groups of 6-OHDA-lesioned rats. With regard to firing pattern, 7.7%(3/39) of ZI neurons discharged regularly, 82.1% (32/39) irregularly and 10. 3% (4/39) in bursts in normal rats. During the second week after 6-OHDA lesion, the regular, irregular and bursting firing neurons recorded in the ZI were 9.4% (3/32), 59. 4% (19/32) and 31.3% (10/32), and during fourth week, the regular, irregular and bursting firing neurons were 14.3% (5/35), 57.1% (20/35) and 28. 6% (10/35), respectively. The firing pattern of the neurons in the three different groups did not change significantly. Conclusion These results suggest that the firing rate of ZI neurons in 6-OHDA-lesioned rats is increased significantly, which may contribute to the pathophysiology of Parkinson's disease.     

Study on T lymphocyte subsets and NK cells in patients with Graves＇ disease combined with type 2 diabetes

Objective To investigate changes in T lymphocyte subsets and NK cells in patients with simple Graves' disease (GD)and Graves' disease combined with type 2 diabetes mellitus (GD/T2DM). Methods Fifteen cases of GD/ T2DM were selected from our hospital from November 2001 to November 2004. Before and after therapy thyroid function, thyroglobulin antibody (TGA), thyroid microsomal antibody (TMA) and blood glucose level were measured, and T lymphocyte subsets (CD3, CD4, CD8, CD4/CD8) and NK cells (CD56) were measured by immunofluorescence double labeling monoclonal antibody and flow cytometry, respectively. At the same time, comparison was made with simple GD (15 cases), T2DM (15 cases) and healthy control (20 cases). Results Before therapy, CD4/CD8, CD4 and NK cells in GD/T2DM were less than normal, and there was no significant difference in comparison with simple GD (P<0.05). In T2DM group, only CD4/CD8 and CD4 were less than those of healthy controls (P<0.05). When thyroid function recovered after 1 to 3 months of methimazole treatment in both GD/T2DM and simple GD groups, various indexes recovered, which were more obvious in simple GD. Conclusion Immune hypofunction of GD may be the key to the immune abnormality of GD/T2DM, which is more significant than that of simple GD or T2DM. The recovery of thyroid function and immune abnormality is not consistent, and the recovery of GD is more significant than that of GD/T2DM.     

应用离心造粒法制备盐酸二甲双胍微丸的研究

目的研究离心造粒粉末层积法制备盐酸二甲双胍微丸。方法采用多功能微丸包衣造粒机制备微晶纤维素空白丸芯和盐酸二甲双胍微丸,并且通过产率、粒径和粒径分布、堆密度、表面形态和圆整度、脆碎度和释放度对盐酸二甲双胍微丸进行质量评价。结果以盐酸二甲双胍∶乳糖∶微晶纤维素=100∶5∶3的比例,主机转速150 r/min,喷浆泵转速20 r/min,供粉速度25 r/min,滚圆6 min,进行制备微丸,获得了很好的效果。结论所制备的盐酸二甲双胍微丸圆整度好,粒径均匀,硬度合格,流动性好,释放完全,无骨架结构。     

脑弥漫性轴索损伤实验装置的研制及动物模型的建立

目的 自制一种脑弥漫性轴索损伤(DAI)装置并成功建立DAI动物模型.方法 自制头颅瞬间旋转损伤装置,使大鼠头颅在瞬间(<3ms)旋转90°造成剪切损伤.观察损伤后大鼠的生命体征及行为学改变;于伤后2、6、12、24、36、72h及10d分别处死损伤组动物,制备脑石蜡切片,行镀银及HE染色,光镜下观察神经轴索变化.结果 伤后大鼠均即刻出现原发昏迷,其中2只于损伤后20min内死亡,余持续时间1-30min不等;伤后大鼠呼吸节律紊乱,瞳孔对光反射减弱或消失,醒后均有程度不等的反应性下降,肢体活动迟缓;肉眼可见广泛蛛网膜下腔出血或脑室出血;光镜下可见皮髓交界区、胼胝体区、脑干、小脑白质等部位的神经轴索有不同程度的肿胀、断裂、轴索球形成,后期有小胶质细胞增生,局部呈巢样聚集.结论 本装置能造成大鼠脑DAI,且具有简便、可控、确切的特点,适合进行中、小型动物DAI模型的实验研究.     

沙棘果油及沙棘籽油对大鼠放射性皮肤损伤的影响

目的观察沙棘果油及沙棘籽油对大鼠放射性皮肤损伤的影响。方法实验用深部X线治疗机,每次以3000 cGy的剂量,照射两次,造成大白鼠臀部放射性皮肤损伤。待动物症状明显后,将Ⅱ度皮肤损伤的动物随机分为6组,即阴性对照组、沙棘果油高剂量组、沙棘果油低剂量组、沙棘籽油高剂量组、沙棘籽油低剂量组以及阳性对照组。沙棘果油及籽油高剂量组,每天在损伤部位涂药两次,而其低剂量组每天涂药一次,阴性对照组每天涂灭菌的注射用水一次,阳性对照组每天涂Solcoseryl-Jelly软膏一次。结果肉眼观察结果显示,连续用药10d后,沙棘果油、籽油及Sol-coseryl-Jelly组动物的局部红斑、水肿明显减轻,创面分泌物明显减少,用药2周后,上述症状明显消退,与阴性对照组比较,明显好转;另外,沙棘果油、籽油及Solcoseryl-Jelly组的创面愈合时间明显缩短。光学显微镜观察结果显示,沙棘果油、籽油及Solcoseryl-Jelly组的皮肤损伤明显减轻,炎症反应亦明显减轻,创面修复明显。电子显微镜观察结果显示,阴性对照组的超微结构明显受损,而沙棘果油、籽油及Solcoseryl-Jelly组的损伤明显减轻。结论沙棘果油及沙棘籽油对大鼠放射性皮肤损伤有明显的治疗作用。     

扑热息痛多腔体贮库式植入剂的制备及体外释放性能检测

目的以聚乳酸-羟基乙酸共聚物（PLGA）为载体,制备扑热息痛贮库式缓释体系,研究其体外释药性能。方法用微机电技术制备扑热息痛多腔体贮库式植入剂,采用高效液相色谱法检测药物的释放性能。本实验采用C18色谱柱,以甲醇-水（15：85）为流动相,检测波长为215nm,流速为0．8mL／min。结果载体形状不同,体外药物释放速率具有明显差异,外方内六边形扑热息痛植入剂缓释曲线符合Higuchi方程。结论扑热息痛多腔体贮库式植入剂制备工艺可行,载体的腔体形状对体外药物释放速度有较大影响。     

WWOX蛋白在非小细胞肺癌中的表达及其临床意义

目的 探讨WWOX(WW domain-containing oxidoreductase)基因在非小细胞肺癌组织中的表达及其临床意义.方法 用免疫组化方法检测50例鳞癌、31例腺癌及20例癌旁正常组织中WWOX基因蛋白的表达,并分析其与各临床病理指标之间的相关性.结果 WWOX基因在72.8%的非小细胞肺癌中失表达或表达减少,而在相邻正常肺组织中有80.0%正常表达.WWOX基因的表达与组织类型、细胞分化程度密切相关(P<0.05),在鳞癌和低分化癌中WWOX基因失表达或表达减少.结论 WWOX蛋白在非小细胞肺癌组织中呈低表达,该蛋白表达的缺失可能在不同类型非小细胞肺癌的形成中发挥了不同的作用.     

汽车注塑件典型外观缺陷分析及消除对策

注塑件在制造过程中经常会出现各种外观缺陷,通过列举汽车注塑件成型过程中典型的质量缺陷,结合实际,从产品设计、模具设计与制造、原材料、注塑工艺等方面,剖析了产生外观缺陷的原因,并提出切实可行的解决办法,以期最大限度的减少外观缺陷,提高注塑件的质量,从而达到满足整车质量目标的要求。