Humanin peptide suppresses apoptosis by interfering with Bax activation

Bax (Bcl2-associated X protein) is an apoptosis-inducing protein that participates in cell death during normal development and in various diseases. Bax resides in an inactive state in the cytosol of many cells. In response to death stimuli, Bax protein undergoes conformational changes that expose membrane-targeting domains, resulting in its translocation to mitochondrial membranes, where Bax inserts and causes release of cytochrome c and other apoptogenic proteins. It is unknown what controls conversion of Bax from the inactive to active conformation. Here we show that Bax interacts with humanin (HN), an anti-apoptotic peptide of 24 amino acids encoded in mammalian genomes. HN prevents the translocation of Bax from cytosol to mitochondria. Conversely, reducing HN expression by small interfering RNAs sensitizes cells to Bax and increases Bax translocation to membranes. HN peptides also block Bax association with isolated mitochondria, and suppress cytochrome c release in vitro. Notably, the mitochondrial genome contains an identical open reading frame, and the mitochondrial version of HN can also bind and suppress Bax. We speculate therefore that HN arose from mitochondria and transferred to the nuclear genome, providing a mechanism for protecting these organelles from Bax.     

Primary observations of the existence of Fas-like cytoplasmic death factor in plant cells

The main activity of Fas is to trigger cytoplasm death program in animal cells. In G2 pea, vacuole plays a pivotal role in inducing cell death in the cytoplasm of longday (LD) grown apical meristem cells. Expression patterns of the Fas in G2 pea cells revealed that the Fas is mainly localized in the vacuole of cells undergoing programmed cell death (PCD). The Fas expression is corresponding to the initiation of menadione-induced PCD in tobacco protoplasts.The results suggest the existence of the Fas-like mediated cytoplasmic death pathway in plant cells.``     

石油钻机刹车块材料筛选的原理与试验方法

本文根据石油钻机刹车工作理论和摩擦学的基本原理,用系统分析的方法,在大量试验的基础上,结合我国实际情况,提出了一套石油钻机刹车块材料筛选的原理与实验方法。筛选原理包括刹车块材料特性指标和刹车块材料的摩擦学系统特性。根据筛选原理所建立的试验方法体系由三级试验组成,即基本摩擦学特性试验、热冲击制动摩擦学特性试验和缩尺刹车副模拟工况制动摩擦学特性试验。用本实验方法,可以科学地筛选出适合不同条件下工作的各种刹车块,从而可充分利用刹车块的性能,延长其使用寿命。几年来,已为国内几家刹车块生产厂家所采用,提高了产品质量,开发出多种新产品,其中有两种产品获得国家优质产品奖。     

ZQ高压功率二极管的玻璃钝化研究

本文研究报导了ZQ高压功率二极管的玻璃钝化方法,采用适当的腐蚀技术、玻璃粉涂敷技术和玻璃微晶化技术,获得了良好的内层玻璃钝化膜。实验结果表明,用该膜钝化的ZQ器件具有优良的可靠性和高温工作特性。     

试论饭店业员工培训

随着饭店业的发展，越来越多的饭店企业开始重视员工培训，注重员工整体素质的提高，但是由于在培训认识、体制、教学方法以及评估等方面存在种种问题，使得培训效果与预期目标相距甚远。文章分析了当前饭店业培训工作中存在的问题，并尝试提出了解决问题的途径及方法。     

基于视频的学生坐姿检测与纠正系统研究

为了解决中小学生坐姿不正确的问题,本文提出了一种基于视频的学生坐姿检测与纠正方法的解决方案,采用计算机视觉领域中的运动目标检测技术,实时监控学生的坐姿,并对不正确的姿势进行提醒与纠正.系统首先对学生坐姿进行视频采集,并由背景差分法得到基本准确的前景图像;然后对图像进行高斯滤波和形态学处理;再利用经验阈值对图像进行二值化处理;最后利用形态学滤波和区域面积检测法得到当前的学生姿态,与正常姿态进行对比后,对不正确的姿态进行提醒和纠正.     

试析目前企业工人的地位和作用

目前,企业中工人的地位得不到重视,逐渐成为社会的弱势群体,笔者根据目前工人在企业中的状况作一简单阐述.     

1.10—菲萝啉及荧光桃红萃取光度法测铝中的微量锰

本文研究了锰-1.10菲箩啉-荧光桃红萃取光度法测定锰的条件.在弱酸性及中性条件下锰(Ⅱ)与1.10-菲萝啉及荧光桃红形成可被氯仿萃取的[Mn(Phen)_2]Phlo络合物,最大吸收波长λ_(man)=562.8nm,s=1.073×10~6L mol~(-1)·cm~(-1),其含量在0～10μg/10ml氯仿呈线性关系.     

电脉冲孕育处理对方坯连铸09CuPCrNi钢凝固组织的影响

在鞍钢工业生产中进行了利用电脉冲孕育技术改善和细化连铸坯凝固组织的探索性实验研究.实验钢种为09CuPCrNi,连铸坯的尺寸规格为150mm×150mm.实验结果表明,在连铸中间罐内对09CuPCrNi钢水进行电脉冲孕育处理可以明显细化连铸坯的凝固组织.与未经电脉冲孕育处理的连铸坯相比,经电脉冲孕育处理后,连铸坯的柱状晶长度明显缩短,一次枝晶臂间距明显减小;连铸坯的中心等轴晶区扩大,中心缩孔得到明显改善.轧材性能达到了技术要求.