增殖抑制基因和血管内皮生长因子在胃癌中的表达及其意义

目的探讨增殖抑制基因(HSG)以及血管内皮生长因子(VEGF)在胃癌中的表达及其意义。方法采用免疫组化法检测HSG和VEGF在胃正常黏膜、癌旁组织及胃癌组织中的表达。结果胃正常黏膜、癌旁组织及胃癌组织HSG的阳性表达率分别为66.7%、58.0%和38.3%,正常黏膜组到胃癌组HSG表达率呈递减趋势,差异有统计学意义(P<0.05);VEGF在3组中的阳性表达率分别为13.3%、20.0%和68.3%,正常黏膜组到胃癌组的表达率呈递增趋势,差异有统计学意义(P<0.05);Spearman等级相关分析显示,HSG与VEGF表达呈负相关(r=-0.847,P<0.05)。结论 HSG与VEGF的过表达可能是胃癌发生发展以及转移的重要原因之一。     

越南Ha Nam省近十年来土地利用变化研究

采用单一土地利用动态度、土地利用度、Gibbs-Martin多样化指数、城市扩展强度、人口一城市扩展指数等定量指标,对越南Ha Nam省近10年来的土地利用变化进行了探讨.结果表明:2000-2010年,越南Ha Nam省土地利用发生了大幅度的变化.     

甘肃省公路地质灾害综合发育强度指数计算方法

在甘肃公路地质灾害类型及区划研究基础上,对各类致灾因子强度进行分级,并进行无量纲化标度,利用数学综合统计分析原理,提出甘肃省公路地质灾害综合发育强度指数计算方法.     

基于教育的人力资本投资对经济增长贡献的研究

随着教育水平的提高,基于教育的人力资本投资越来越受到人们的关注.建立模型,将教育投资与物资资本投资对经济增长的作用进行比较研究,可对结论给出政策模拟.     

论转变经济发展方式的实践性

党的十七大报告明确指出要加快转变我国的经济发展方式.经济发展和经济增长有着本质的区别,转变经济发展方式的内涵丰富,对我国经济的发展有着重要的指导性和实践性.我国要从根本上扭转为生产而发展生产,盲目追求GDP的增长.实现以人为本的发展,更加注重关心民生、改善民生、保障民生,坚持走生产发展、生活富裕、生态良好的文明发展道路.     

Remaining fatigue life assessment of corroded mooring chains using crack growth modelling

Failures caused by the combined actions of fatigue, corrosion and wear are important safety concerns for mooring chains used on floating structures in the oil and gas industry. Prediction of remaining corrosion fatigue life based on surface condition could therefore be a useful tool for the continued safe operation of corroded chains. This paper investigates the use of crack growth modelling for estimating the remaining corrosion fatigue life of mooring chains that exhibit significant pitting corrosion damage. A crack growth modelling approach is used to produce remaining fatigue life estimates for a selection of severely pitted mooring chains. Using fatigue crack growth rate test results for grade R4 high strength mooring chain steel, empirical crack growth laws are presented for free corrosion and cathodic protection conditions at load ratio R = 0.1. Two different methods for establishing equivalent cracks from surface scans of corrosion damage are presented. The mooring chains are proof loaded as part of their manufacturing process. Residual stresses introduced during this process have therefore been determined by finite element analysis and accounted for in the fatigue crack growth predictions. One of the equivalent crack models, accounting for the single dominant corrosion pit, provided quite accurate fatigue life predictions when compared with full scale test results.