以科技创新引领企业可持续发展(续)——在“构建河北现代产业体系”高层论坛上的发言

（上接2010年第1期） 从我国目前情况来看,企业科技实力相对薄弱,科研与市场脱节,产、学、研结合不够紧密,科技成果难以转换成现实生产力,这是导致我国许多产业技术研究水平较低、竞争力不强的主要原因。     

Transfection of glutathione S-transferase (GST)-pi antisense complementary DNA increases the sensitivity of a colon cancer cell line to adriamycin, cisplatin, melphalan, and etoposide

The goal of this study was to demonstrate that glutathione S-transferase (GST)-pi is directly involved in the intrinsic and acquired resistance of cancer cells to anticancer drugs. To this end, GST-pi antisense cDNA was transfected into the cultured human colon cancer cell line M7609, which expresses an innately high level of GST-pi and shows intrinsic drug resistance, and into an M7609 strain with acquired resistance to Adriamycin (ADR;i.e., M7609/ADR cells). The changes in the sensitivity of these transfectants to various anticancer drugs were investigated. The intracellular concentrations of GST-pi in M7609/anti-1 cells and M7609/anti-2 cells, two clones that were established by transfection of GST-pi antisense cDNA into M7609 cells, were decreased to approximately half of those detected in the parent cells (M7609) and in the control cells transfected with vector alone (M7609/pLJ). The sensitivities of the antisense transfectants in relation to ADR, cisplatin, melphalan, and etoposide were increased -3.3-fold, 2.3-fold, 2.2-fold, and 2.1-fold, respectively, compared with those of M7609 and M7609/pLJ. On the other hand, the sensitivities of the antisense transfectants to Taxol, vincristine, 5-fluorouracil, and mitomycin C were not significantly changed. Similarly, the transfection of antisense cDNA into M7609/ADR cells resulted in the reduction of intracellular GST-pi concentration (by about half) and an increased sensitivity to ADR (4.4-fold), but no increase in 5-fluorouracil sensitivity. Thus, GST-pi is considered to be a multidrug resistance factor that is responsible for both the intrinsic and acquired resistance of cancer cells to anticancer drugs such as ADR, cisplatin, melphalan, and etoposide.     

三维陈述式约束模型的自动生成

由于缺乏有效的自动生成约束模型的方法，三维变量化技术的进一步发展受到制约，通过转换边界表示和提取特征中的本质约束信息，自动生成三维陈述式约束模型，以InteSolid2.0为基础，实现了原型系统。     

基于分段地址结构的快速路由查找算法

根据IPV6地址结构和骨干路由表特点,分析了原有路由查找算法,基于IPV6的掩码长度和分段地址,采用Hash表和多分支Trie树结构,提出了一种快速的IPV6路由查找算法。根据分段地址和掩码将最常用到的路由前缀按前缀长度设置Hash表,并将前缀值有序存放在表结点中。不仅可以进行前缀长度的二分查找,同时又是其它前缀匹配的索引。对于其他的前缀匹配问题,根据Hash表中的索引到相应的多分支Trie树完成最长前缀匹配。实践证明该算法具有较好的时空效率,可以较好地提高路由查找速度。     

The formation of protective films on iron-silicon alloys

The oxidation of high purity FeSi alloys was studied over the temperature range 765–965°C by means of a micro-balance. In hydrogen with 2.5% water vapour only silicon was oxidized. Specimens with 1% Si showed mostly internal oxidation. External layers of SiO₂ formed on specimens with 2 and 3.4% Si. These layers also hindered the oxidation of iron. The oxidation of Fe could be distinguished from oxidation of Si by reduction of the Fe oxides. The low oxidation rates reached at 865° after long times of exposure were ascribed mainly to the oxidation of Si.     

数据挖掘中的数据分类算法综述

在数据挖掘的过程中,使用到很多分类算法,可见分类算法在数据挖掘中占有非常重要的地位。数据分类算法有很多种,各有不同的优缺点,因此,通过对不同算法特性的研究,有助于后期对算法进行相应的改进,确保新的分类算法能够具备更好的实用性能。数据分类算法的性能优良,不仅可以提高数据挖掘的功能性和实用性,还可以确保使用者对算法具备更多的选择性,基于此,对数据挖掘中不同的数据分类算法进行了研究和分析。     

Enhancing the Therapeutic Potential of Mesenchymal Stromal Cell-Based Therapies with an Anti-Fibrotic Agent for the Treatment of Chronic Kidney Disease

Chronic kidney disease (CKD) affects 1 in 10 members of the general population, placing these patients at an increasingly high risk of kidney failure. Despite the significant burden of CKD on various healthcare systems, there are no effective cures that reverse or even halt its progression. In recent years, human bone-marrow-derived mesenchymal stromal cells (BM-MSCs) have been recognised as a novel therapy for CKDs, owing to their well-established immunomodulatory and tissue-reparative properties in preclinical settings, and their promising safety profile that has been demonstrated in patients with CKDs from several clinical trials. However, renal fibrosis (scarring), a hallmark of CKD, has been shown to impair the viability and functionality of BM-MSCs post-transplantation. This has suggested that BM-MSCs might require a pre-treatment or adjunct therapy that can enhance the viability and therapeutic efficacy of these stromal cells in chronic disease settings. To address this, recent studies that have combined BM-MSCs with the anti-fibrotic drug serelaxin (RLX), have demonstrated the enhanced therapeutic potential of this combination therapy in normotensive and hypertensive preclinical models of CKD. In this review, a critical appraisal of the preclinical data available on the anti-fibrotic and renoprotective actions of BM-MSCs or RLX alone and when combined, as a treatment option for normotensive vs. hypertensive CKD, is discussed.     

页岩气钻完井技术现状及难点分析

页岩气勘探开发在中国刚刚起步,缺乏相关技术经验。为此,介绍了国外页岩气钻完井技术现状及最新进展。国外页岩气开发先后经历了直井、单支水平井、多分支水平井、丛式井、丛式水平井钻井（PAD水平井）的发展历程;目前水平井已成为页岩气开发的主要钻井方式,页岩气水平井钻井要考虑其成本,垂直井段的深度不超过3 000 m,水平井段的长度介于500～2 500 m;PAD水平井钻井利用一个钻井平台作为钻井点,先后钻多口水平井,可以降低成本、节约时间,是比较新的页岩气钻井技术;页岩气固井主要采用泡沫水泥固井技术,完井方式以套管固井后射孔完井为主。在综合分析国外页岩气钻完井技术及钻完井难点的基础上,指出国内页岩气钻井应着力解决在保持井壁稳定、预防事故、降低钻井成本、研发配套仪器和优选钻井液配方等方面存在的问题。     

固体火箭发动机可靠性增长试验规划初步研究

研究了固体火箭发动机产品总数一定情况下可靠性增长试验量的确定问题．提出了模型假设，以剩余产品成功数期望值最大作为目标函数，建立数学模型；然后，在初始故障数服从泊松分布时，推导了确定可靠性增长试验量的极大一极小准则，给出了产品研制后期故障数的替代分布．最后给出了一个应用实例，结果表明该准则有点保守，但较为稳健．     

河北省关闭煤矿地质环境影响评价

在对河北省主要的关闭煤矿实地调查和遥感影像解译基础上,将关闭煤矿的地质环境影响评价指标体系划分为3个要素和11个指标,利用模糊综合评价方法建立了关闭煤矿的地质环境影响评价模型,采用改良指数标度的层次分析法确定各指标权重。评价结果显示,在118处较大规模的关闭煤矿中,36处煤矿地质环境影响程度为严重和较严重状态,82处为轻微和较轻状态。严重、较严重的煤矿主要分布在蔚县矿区、宣下矿区、邯郸矿区。地质环境问题主要影响因子为土地资源压占、含水层破坏、地面塌陷和地裂缝等。