可变情报板诱导系统设计中重点问题研究

一、前言 为缓解日益紧张的交通拥堵状况，提高交通系统和设施运行效率并提升交通管理和信息服务水平，通过对交通信息的采集、传输、处理和应用，建立服务良好、运输高效、管理科学的智能交通系统，已成为国内各主要大中城市的发展方向。智能交通系统在这些城市的发展趋势为：一是着眼于交通信息的广泛应用与服务，二是着眼于提高交通设施的运行效率。[第一段]     

如何延长活塞环的使用寿命

近年来,随着汽车发动机功率和转速的不断增加,对活塞环的性能与寿命要求越来越高,如何延长活塞环的使用寿命呢?本文将从以下几个方面阐述.     

浅谈东南公路高填土板涵的设计

本文通过列举东南公路中上堡板涵的设计实例，简要说明了高填土板涵的设计心得。     

U型桥台病害分析及对策

针对U型桥台在工程实践中容易发生的病害,提出在设计中应注意的关键性问题及改进措施.     

机车空压机润滑油乳化的分析与改进

对内燃机车用螺杆空气压缩机润滑油乳化现象进行分析;针对润滑油乳化原因提出改进建议.     

大荔县婴幼儿佝偻病分布及流行因素

为了解大荔县婴幼儿佝偻病发、患病规律及有关的流行因素,于1987年春、秋进行了两次流行病学调查。结果是:在调查的1988名3岁以内婴幼儿中,患病930人,患病率46.8%。1岁内婴儿发病率69.6%。患病率随年龄的增加而降低,各年龄组间患病率差异非常显著(P<0.01)。婴儿期发病的流行因素是,出生季节、母亲文化程度。1～3岁幼儿患病的流行因素是年龄、主食种类、居室朝向和患其它疾病情况。提示:婴儿期佝偻病发病最高,是预防佝偻病的重点人群。由于影响发、患病的流行因素较多,应对婴、幼儿分别采取有针对性的方法进行防治,降低发、患病率。     

浅谈“公交车辆运营信息采集分析系统”的开发与应用

针对基层公交线路管理手段相对落后、车辆营运秩序难以人为进行规范的问题 ,阐述公交车辆运营信息采集分析系统的开发与应用。     

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.