Nicastrin modulates presenilin-mediated notch/glp-1 signal transduction and betaAPP processing

Nicastrin, a transmembrane glycoprotein, forms high molecular weight complexes with presenilin 1 and presenilin 2. Suppression of nicastrin expression in Caenorhabditis elegans embryos induces a subset of notch/glp-1 phenotypes similar to those induced by simultaneous null mutations in both presenilin homologues of C. elegans (sel-12 and hop-1). Nicastrin also binds carboxy-terminal derivatives of beta-amyloid precursor protein (betaAPP), and modulates the production of the amyloid beta-peptide (A beta) from these derivatives. Missense mutations in a conserved hydrophilic domain of nicastrin increase A beta42 and A beta40 peptide secretion. Deletions in this domain inhibit A beta production. Nicastrin and presenilins are therefore likely to be functional components of a multimeric complex necessary for the intramembranous proteolysis of proteins such as Notch/GLP-1 and betaAPP.     

Evidence that humans evolved from a knuckle-walking ancestor

Bipedalism has traditionally been regarded as the fundamental adaptation that sets hominids apart from other primates. Fossil evidence demonstrates that by 4.1 million years ago, and perhaps earlier, hominids exhibited adaptations to bipedal walking. At present, however, the fossil record offers little information about the origin of bipedalism, and despite nearly a century of research on existing fossils and comparative anatomy, there is still no consensus concerning the mode of locomotion that preceded bipedalism. Here we present evidence that fossils attributed to Australopithecus anamensis (KNM-ER 20419) and A. afarensis (AL 288-1) retain specialized wrist morphology associated with knuckle-walking. This distal radial morphology differs from that of later hominids and non-knuckle-walking anthropoid primates, suggesting that knuckle-walking is a derived feature of the African ape and human clade. This removes key morphological evidence for a Pan-Gorilla clade, and suggests that bipedal hominids evolved from a knuckle-walking ancestor that was already partly terrestrial.     

一类广义Ep半无限规划的鞍点条件

在E凸函数的基础上，定义了一类Ep-凸函数，研究了关于此类函数的鞍点条件、得出了鞍点条件、鞍点与最优值的等价性条件．     

谈如何加强煤矿的瓦斯治理

瓦斯事故的发生在煤矿事故中扮演着非常重要的角色，怎么对瓦斯进行更好的治理，从而更好的遏制瓦斯事故的发生就成为一个重要的课题，本文从瓦斯检测、加强放炮管理、加强盲巷管理等方面阐述了如何进行更加有效地瓦斯治理。     

非接触式霍尔位移传感器的研制及应用

介绍了一种利用霍尔效应实现位移测量的新型传感器，实验研究表明：在3mm的量程范围内精度可以达到0．01mm．应用这种传感器，可以实现钢管、钢棒、钢丝绳等细长构件的直径动态连续测量．     

剖宫产术并发羊水栓塞致产妇死亡1例

1病例资料患者23岁,住院号2601375。因G2P0孕39＋2W,规律腹阵痛6h,于2006年2月12日7∶30入院。定期在外院产检,无特殊,孕期体健,否认既往有心肺疾患病史。查：T：36.8℃,P：76次/min,R：18次/min,BP：110/70mmHg（1mmHg=0.1333kPa）。一般情况好,水肿（一）,心肺正常。腹胀膨隆,软,无压痛,肝脾未触及肿大。     

广西猫儿山之土壤

猫儿山地处亚热带季风气候，以常绿阔叶林为主的自然森林植被生长茂盛，土壤矿物分解较彻底，成土过程主要是脱硅富铝化过程和旺盛的生物富集过程。主要土壤类型为红、黄壤系列土壤。土壤的垂直分布规律明显。基带土壤为红壤，自山麓至山顶依次为山地红壤、山地黄红壤、山地黄壤和山地淮黄壤。土壤质地多为砂壤土至粘土，土壤剖面层次发育明显，盐基和粘粒的淋溶迁移和淀积作用强烈，全剖面呈酸性至强酸性反应，盐基高度不饱和，代换量低，但表土有机质含量丰富，肥力高，是广西重要的水源林区。     

二苯羟乙酸糖酯酶促合成

二苯羟乙酸衍生物及糖类化合物分别具有重要的生理功能．二苯羟乙酸糖酯有可能同样具有一定的生理价值．本文着重对这类化合物的酶促合成进行探讨，选择定位合成二苯羟乙酸糖酯．     

基于人工神经网络的热轧碳钢变形抗力预报

以恒应变速率凸轮压缩试验机得到的实验数据为基础，采用人工神经网络的方法建立了碳钢变形抗力与应变、庆变速率及温度对应关系的预测模型，与多元非线性回归模型比较，神经网络模型具有较高的预测精度。