Discovery of Dual ETA/ETB Receptor Antagonists from Traditional Chinese Herbs through in Silico and in Vitro Screening

Endothelin-1 receptors (ETAR and ETBR) act as a pivotal regulator in the biological effects of ET-1 and represent a potential drug target for the treatment of multiple cardiovascular diseases. The purpose of the study is to discover dual ETA/ETB receptor antagonists from traditional Chinese herbs. Ligand- and structure-based virtual screening was performed to screen an in-house database of traditional Chinese herbs, followed by a series of in vitro bioassay evaluation. Aristolochic acid A (AAA) was first confirmed to be a dual ETA/ETB receptor antagonist based intracellular calcium influx assay and impedance-based assay. Dose-response curves showed that AAA can block both ETAR and ETBR with IC₅₀ of 7.91 and 7.40 μM, respectively. Target specificity and cytotoxicity bioassay proved that AAA is a selective dual ETA/ETB receptor antagonist and has no significant cytotoxicity on HEK293/ETAR and HEK293/ETBR cells within 24 h. It is a feasible and effective approach to discover bioactive compounds from traditional Chinese herbs using in silico screening combined with in vitro bioassay evaluation. The structural characteristic of AAA for its activity was especially interpreted, which could provide valuable reference for the further structural modification of AAA.     

欧盟和德国建设工程产品管理

鉴于我国建设工程产品管理的现状,文章讨论了欧盟和德国在建设工程领域的管理体系和模式,并着重介绍了欧盟建设工程领域CE认证的市场准入机制,以期增加对国外相关领域的了解,一方面有助于企业走向国际市场,另一方面有助于我们思考中国市场应如何管理.     

Surface Oxidation as a Cause of High Open‐Circuit Voltage in CdSe ETA Solar Cells

TiO₂/CdSe/CuSCN extremely thin absorber (ETA) solar cells are found to give relatively high values of open‐circuit voltage (>0.8 V) but low currents upon annealing the cadmium selenide (CdSe) in air (500 ºC). Annealing in N₂ produces much lower photovoltages and slightly lower photocurrents. Band structure measurements show differences between the two annealing regimes that, however, appear to favor the N₂‐annealed CdSe. On the other hand, chemically resolved electrical measurements (CREM) of the cells reveal marked differences in photo‐induced charge trapping, in particular at absorber grain boundaries of the air versus N₂‐annealed systems, correlated with the formation of Cd–O species at the CdSe surface. Using transient absorption and photovoltage decay, pronounced lifetime differences are also observed, in agreement with the strong suppression of charge recombination. The results point to a multiple role of grain surface‐oxidation, which both impedes electron injection from the CdSe to the TiO_2, but, much more significantly, enhances hole injection to the CuSCN via passivation of hole traps that act as efficient recombination centers.     

Microstructured extremely thin absorber solar cells

In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO₂ microstructures produced by embossing. Nanocrystalline or compact TiO₂ films on Indium doped tin oxide (ITO) glass substrates were embossed by pressing a silicon stamp containing a μm size raised grid structure into the TiO₂ by use of a hydraulic press (1 ton/50 cm²). The performance of these microstructured substrates in a ETA cell sensitized by a thermally evaporated or chemical bath deposited PbS film and completed by a PEDOT:PSS hole conductor layer and a Au counter electrode is compared to that of planar substrates. Surprisingly planar films produced better performance than micro-structured films. A simple model implying photoconductive shunting paths revealed by junction breakdown at negative bias under illumination is presented.     

基于ETA模型的配筋措施对于高拱坝变形损伤指标的影响

混凝土拱坝在不同强度超载地震作用下的动力响应,对拱坝抗震裕度评估有着深远的影响,如何评价配筋措施的效果成为一个重要问题。基于耐震时程分析（ETA）法,研究了不同地震强度下,高拱坝是否采用配筋抗震措施对于坝体损伤变形指标的影响。首先对ETA方法、坝体材料本构、横缝模型以及地震动输入方法进行了介绍。然后分别建立了高拱坝采用配筋抗震措施和未采用配筋抗震措施拱坝的数值模型,同时基于ETA方法生成不同地震强度的耐震时程。分析在不同地震强度下,高拱坝是否采用配筋抗震措施的损伤分布、横缝开度以及变形等响应,提出了高拱坝损伤体积比、平均横缝开度以及拱冠梁变形等坝体损伤变形指标。通过对比高拱坝配筋和未配筋的情况下得出的动力响应指标,研究配筋措施对高拱坝响应以及损伤变形指标趋势、相关性以及离散性的影响。计算结果表明:在不同的地震动强度条件下,配筋措施对减小高拱坝的整体损伤是有效的,对横缝开度及位移影响有限,配筋措施可以减小地震随机性导致的损伤变形指标离散。同时,归一化的损伤变形指标表明损伤变形指标有一定的相关性。     

重力坝抗震性能的POA-ETA评价方法

本文结合耐震时程法(ETA)和静力弹塑性分析法(POA)各自的优点,提出了能够考虑结构多阶振型、地震随机性影响的POA-ETA法,并以此对混凝土重力坝进行抗震性能分析。通过分别对ETA和POA基本原理进行分析,总结了POA-ETA法的基本原理以及实施的关键步骤。采用ETA法生成不同峰值加速度的ETA时程,并以此作为激励,得到结构的动力响应。通过动力响应结果,得到结构的能力谱曲线,延性比-等效周期比,延性比-等效阻尼比曲线,并以此代入POA法中评价结构的抗震性能。本文采用Koyna混凝土重力坝模型,使用提出的POA-ETA法对坝体结构"中等破坏"、"严重破坏"两种损伤指标所对应的性能点(谱位移)值进行计算,从而对坝体结构抗震性能及抗震指标进行分析。研究表明,采用POA-ETA法可以得出不同损伤程度下的抗震性能,具有一定的适用性。     

海底管道泄漏的事件树和故障树相结合分析

海底管道一旦发生泄漏,危害很大,为了分析其引起的不同后果,建立了海底管道系统泄漏事件树模型.根据事件树和故障树各自不同的特点,提出了将两者结合运用的方法.将故障树分析应用到已构建好的事件树中,通过故障树的定量分析求出事件树中初因事件和后续事件的发生概率,最终实现事件树的定量分析,得出各后果事件的发生概率.从而得到一个完整的海底管道泄漏危害分析的方法.     

接枝阳离子棉织物的染色性能研究

研究了耐酸大红4BS、耐晒果绿BLL和直接深棕M这3种直接染料在接枝2,3-环氧丙基三甲基氯化铵棉织物上的染色性能.结果表明,棉织物接枝阳离子后上染速率很快,上染率大幅度提高,且实现了无盐染色,染色残液无色透明;阴离子表面活性剂十二烷基硫酸钠对接枝阳离子棉织物用阴离子染料染色具有高效的缓染作用,接枝阳离子棉织物的色牢度均有一定提高.     

采用乙醇胺抑制核电站二回路系统的流动加速腐蚀

分析目前国内压水堆核电站二回路流动加速腐蚀的原因。通过试验室试验和实际应用试验,证明乙醇胺能够明显提高汽水两相流中水相的pH值,可有效抑制二回路的流动加速腐蚀,并能够延长凝结水精处理混床的运行周期。试验没有发现乙醇胺对系统的不良影响。     

Microstructure and bend strength of WC–Co and steel joints

Abstract

Tungsten inert gas arc welding of WC–30 wt-%Co cemented carbide and steel was carried out using a variety of filler alloys. Precipitation of Fe₃W₃C occurred at the joint interface and this reduced the bend strength and toughness of the welded joint. The problem could be alleviated by adjusting the carbon concentration of the filler metal.