黄斑蓝子鱼CRH基因的克隆及其在浅水应激后的mRNA表达

鱼类应激时主要启动两种生理反应系统,即"交感-嗜铬组织"系统/和/或"下丘脑-垂体-肾间组织轴"(HPI轴)系统.在实际生产操作中,鱼类容易受到浅水暴露应激.为了探讨黄斑蓝子鱼在受到浅水应激后HPI轴是否被激活,本研究克隆了下丘脑中启动HPI轴活性的关键因子—促肾上腺皮质激素释放激素(CRH)的基因,并检测其在应激前和受到浅水应激后不同时间点(0、20、40、60、80 min)的mRNA水平.结果显示,CRH前体的cDNA全长为1025 bp,编码170个氨基酸(aa),分别由一个信号肽(24个aa)、一个功能未知保守区(13个aa)和一个成熟肽(41个aa)组成;该CRH前体和成熟肽与其他鱼类的相应肽分别具有62%-98%和78%-100%的序列相似性.当鱼体受到短暂(4 min)浅水应激后80 min内,脑中CRH mRNA水平在应激前后无显著变化(P>0.05),说明黄斑蓝子鱼在受到急性浅水应激后可能主要启动"交感-嗜铬组织"系统而不是HPI轴.     

Distribution of CRH-and ACTH-like immunoreactive cells in amphioxus,Branchiostoma belcheri

Immunocytochemical studies on the nervous system,Hatschek's pit,digestive tract and gonads tissues of an amphioxus(Branchiostoma belcheri)were performed using polyclonal antibodies against human corticotrophin-releasing hormone(CRH)and human adrenocorticotropin(ACTH).The results showed that many CRH-like immunoreactive neurons were distributed specifically on the dorsal side and ventral side of brain vesicle,while a few CRH-like neurons and their fibers in spinal cord.At the same time,the epithelial cells in the basic region of Hatschek's pit were shown immunopositive to CRH antibody.In gonads(ovary and testis),CRH-immunopositive substance was localized in the cytoplasm near oocyte nucleus and in early spermatogenic cells.ACTH-like immunoreactivities were observed specially in the neurons and their protrusions localized on the ventral side of the brain vesicle and in spinal cord,and also in epithelial cells of Hatschek's pit,enteric neurons of digestive tract,oocytes in ovary and in early spermatogenic cells as well.It was found for the first time that CRH-like neurons existed in the middle region of brain vesicle(corresponding to the hypothalamus of vertebrates)and ACTH-like immunopositive cells existed in Hatschek's pit,implying that a control mechanism between brain vesicle and Hatschek's pit maybe had been already built in amphioxus as that in vertebrates.The present study will provide new morphological evidence for the origin and evolution of ACTH.In addition,the immunoreactivities of CRH and ACTH in the digestive tract and gonads suggested other physiological function of CRH and ACTH in amphioxus.     

胎盘促肾上腺皮质激素释放激素研究进展

回顾了关于胎盘促肾上腺皮质激素释放激素研究的最新进展，其内容包括ｐＣＲＨ的合成与分泌、ｐＣＲＨ释放的调节、孕妇血浆ＣＲＨ水平的变化及其对ＨＰＡ轴活动的影响以及ｐＣＲＨ的生物学作用等。作者认为，进一步阐明ｐＣＲＨ的旁分泌，自分泌和长距分泌作用将助于理解妊娠维持，胎儿发育和分娩启动等生理机制。     

制备高纯硅所用的碳化稻壳粉的净化研究

研究了碳化稻壳(CRH)的酸浸除杂、超声酸浸除杂,考察了盐酸浓度、酸浸时间、酸浸温度、酸浸液固比和搅拌速度对除杂效果的影响.得到最佳工艺为:CRH粒度在75μm以下、盐酸质量分数为5%、反应时间3h、水浴温度60℃、浸出液固比14∶1、搅拌速度60r/min.在此最佳工艺条件下,CRH中金属元素的总去除率达96.41%、非金属元素的总去除率达66.68%.实验同时也探讨了超声场作用下酸浸时间对杂质去除效果的影响,最终金属元素的总去除率和非金属元素的总去除率分别达到了99.07%和71.77%.     

Research on dynamical derailment system for CRH

With the vehicle speed increase, wheel-rail dynamic coupling becomes stronger and shows more prominent. It may lead to derailment of the vehicle. Based on an improved three-dimensional wheel-rail contact trace algorithm and a new model of wheel-rail contact force, wheel-rail derailment dynamical model is established on CRH vehicle and developed in MATLAB software, which is called dynamical derailment system for CRH (DDSCRH). Analyzed on dynamical derailment process of high speed vehicle by DDSCRH, the critical position on climb wheel and influence factors on lateral force for derailment is obtained. Finally, high-speed vehicle dynamical simulation is verified on DDSCRH by comparing with the results of line test.     

基于HLA/RTI的CRH2列车协同仿真接口网关设计与实现

以CRH2型高速列车为参考模型,采用多学科协同仿真的方法,对高速列车综合仿真平台和列车通信网络仿真平台之间的接口网关进行分析和研究,提出构建基于HLA/RTI(高层体系结构/联邦运行支撑环境)标准的综合仿真平台与通信网络仿真平台相匹配的接口网关,使得网络仿真平台作为一个联邦成员加入联邦执行中,参与协同仿真。基于HLA/RTI对综合仿真平台中的司机控制台系统和牵引传动系统进行仿真模拟,验证了该接口网关的有效性。     

CRH2动车转向架构架疲劳强度分析

针对CRH2动车组动车转向架焊接构架,从模拟计算和线路实测两方面得到构架上关键部位的等效应力,并依据JIS E 4207规范进行了静强度和疲劳强度评估.两种分析结果的比较表明,各关键点的实测等效应力均小于计算值,这为正确使用规范以及制定符合我国线路条件的设计规范提供了依据.     

CRH3型动车组ATP车载设备安全性分析及故障处理研究

文章分析了CRH3型动车组车载设备ATP在运行过程中存在诸如物理打击、电磁干扰等潜在的安全隐患,并提出了相应的防护措施.讨论了机车一体化设计与设备维护的问题.在总结CRH3型动车组维护工作的基础上,分析了目前在ATP设备维护方面面临的问题及其针对性的解决方案.