国产米力农对急性心肌梗塞心力衰竭犬的血流动力学效应

以结扎麻醉犬冠状动脉前降支致心力衰竭，观察国产米力农的急性血流动力学效应。静脉注射米力衣（6μg／kg），可明显增加左、右心室内压上升和下降的最大速率（±dp／dtmax）及每搏输出量（SV）；显著降低左室舒张末期压力（LVEDP）；肺动脉压于一过性升高后持续下降。提示米力农对急性心肌梗塞所致心力衰竭具有良好的血流动力学效应。     

岩溶地层超长钻孔桩护筒跟进成孔施工技术

岩溶地区桩基施工面临成孔难、易漏浆、常塌孔等技术难题,结合贵广铁路大塘口双线特大桥岩溶区超长钻孔桩基的施工,介绍了采用多层钢套筒跟进．抛投片石、黏土、水泥封堵小洞和混凝土封堵大洞等方法,成功解决各项技术难题,保证了桩基的成孔质量,为类似地区桩基施工提供了可借鉴经验。     

立交工程软弱土层基坑防护结构受力分析

随着城市规模的不断扩大和铁路的快速发展,市政道路与铁路立交工程逐渐增多。高规格的市政道路使铁路地道越做越大,同时,新建高速铁路严格的沉降控制对工程实施提出了更高的要求。为了确保市政设施及铁路的安全,必须对越做越大的基坑工程进行有效的防护。以典型的高水位、软弱土层、大面积的基坑工程为例,采用钻孔灌注桩为防护结构主体,用冠梁、桩间腰梁、水平内撑、水平斜撑等方式对基坑工程进行了加强。对施工过程中结构的受力与变形情况进行了详细的分析。经现场实际实施,支护系统稳定安全。     

更换公路旧桥支座的顶升方案

对更换支座的方法进行了分析总结,并在河北省新乐市-沙河大桥施工中,提出了一种简单易行、节约投资的支座更换方法-兜子顶升法;对该法的设计、作用原理进行了阐述,并介绍了其施工过程,为今后更换桥梁支座提供参考.     

城市轨道交通超大客流网络拥挤传播研究

为研究城市轨道交通超大客流传播的时间规律以及不同数量拥堵站点对整体轨道交通网络的影响,通过定义超大客流,引用疾病传播理论,建立了基于网络拥挤模型的超大客流拥堵网络疾病传播模型,并运用Adams微分方程数值进行模型求解。对反演参数得到的SIR传染病模型的传播特性拟合运用于轨道交通网络,并通过不同的初始拥堵站点数量进行仿真。研究表明：轨道交通超大客流的病态传播受传染概率、恢复概率、初始拥堵站点数影响,该联系为超大客流网络拥挤传播提供一种新的研究思路。     

山区现浇箱形拱桥超大高度支架设计及计算

梨子榜I号大桥主桥为主跨120m的混凝土三箱等截面悬链线拱桥。根据现场条件,采用了落地式现浇组合支架施工,其中,拱脚段采用落地碗扣支架,其他段采用大钢管支架上搭设碗扣支架,文章详细介绍了现浇支架的设计与计算方法。     

甲状腺上皮细胞DR抗原异常表达及影响因素

本文应用单克隆抗体及免疫组化技术对37例自身免疫性甲状腺炎,23例甲亢及13例甲亢伴甲状腺炎甲状腺上皮细胞DR抗原异常表达进行原位研究。结果发现甲状腺上皮细胞DR抗原的异常表达与甲状腺浸润细胞总数、炎性破坏程度及外周血TSH、甲状腺球蛋白抗体、甲状腺微粒体抗体量呈正相关。     

A fuzzy method for predicting the demand for rail freight transportation

The demand for rail freight transportation is a continuously changing process over space and time and is affected by many quantitative and qualitative factors. In order to develop a more rational transport planning process to be followed by railway organizations, there is a need to accurately forecast freight demand under a dynamic and uncertain environment. In conventional linear regression analysis, the deviations between the observed and the estimated values are supposed to be due to observation errors. In this paper, taking a different perspective, these deviations are regarded as the fuzziness of the system's structure. The details of fuzzy linear regression method are put forward and discussed in the paper. Based on an analyzes of the characteristics of the rail transportation problem, the proposed model was successfully applied to a real example from China. The results of that application are also presented here.     

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload

Objective To determine whether reduction In central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-lead or is due to arterial dilation. Methods We compared effects of NTG with these of lower body negative pressure (LBNP). Hemodyunmic measurements were made at rest, during LBNP (10, 20 and 30 mmHg, each for 15 min) and after NTG (10, 30 and 100μg/min, each dose for 15 min) in ten healthy volunteers. Cardiac pre-lead, stroke volume and cardiac output were assessed by echacardiography. Central pressure an mnentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30μg/min) reduced pre-lead (as measured by the peak velocity of the S wave in the superior vena eava) to a similar degree [by (26. 8 ± 3.8) % and (23.9 ± 3. 4) %, respectively]. Compared to LBNP, NTG reduced systemic vascular resistance [by (32. 9 ± 7.5) %, p< 0. 01], decreased peripheral and central pressure augmentation [by (20. 8 ± 3. 4)% units and (12. 9±2. 9)% units, respectively, each P< 0. 01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.     

机构投资者持股与上市公司信息披露行为研究

研究采用我国上市公司2005年至2008年会计年报数据,实证检验机构投资者持股对于多角度公司信息披露行为的影响。研究发现机构持股比例越高的公司年报披露越及时,但是持有同一家上市公司的机构数量越多反而会延迟年报的披露;同时还发现机构持股对于上市公司年报的审计意见类型和年报的补充公告影响并不显著,说明我国机构投资者对于上市公司的内部治理作用还十分有限。