Manganese(II)‐Mediated Domino Annulation Reaction of Vinyl Azides and 4‐Hydroxycoumarin: A Stereoselective Synthesis of Spirobenzofuranone‐lactams

A manganese(II) acetate‐catalyzed domino reaction of vinyl azides and 4‐hydroxycoumarin has been developed for the synthesis of polyfunctionalized spirofuranone‐lactams. A wide range of vinyl azides are capable of providing the desired spirofuranone‐lactams in good to excellent yields. The reaction was achieved via thermal decomposition of vinyl azides to 2H‐azirines, followed by an intramolecular nucleophilic attack and stereoselective cyclization. The mild reaction conditions and easy operation make this reaction advantageous for the synthesis of spirofuranone‐lactams.

     

Numerical modeling of the 2008 Wenchuan earthquake-triggered Niumiangou landslide considering effects of pore-water pressure

Bulletin of Engineering Geology and the Environment - Ring-shear experiments are commonly conducted to analyze the kinematic mechanisms of landslides triggered by earthquakes, particularly for...     

Production of glass-ceramics using Municipal solid waste incineration fly ash

Municipal solid waste incineration(MSWI) fly ash is a by-product from municipal waste incineration.According to incomplete statistics, each year more than one million tons MSWI fly ash was produced in China. Owing to high heavy elements content, widely used disposal methods of landfill are not suitable for MSWI fly ash treatment. In this study, by using MSWI fly ash as raw materials, glassceramics was synthesized for the solidification of heavy metals and waste recycle. Process parameters, including composition, heat treatment temperature and time, were studied and optimized. Under optimizing conditions, the product has good properties of density of 3.42 g·cm~(-3) and Vickers hardness of 6.91 GPa. Moreover, the leaching concentration of heavy metal elements meets allowable values of toxicity characteristic leaching procedure(TCLP).This study offers an alternative for MSWI fly ash recycle.     

Pharmacokinetic Comparison of Berberine in Rat Plasma after Oral Administration of Berberine Hydrochloride in Normal and Post Inflammation Irritable Bowel Syndrome Rats

In the present study, post inflammation irritable bowel syndrome (PI-IBS) rats were firstly established by intracolonic instillation of acetic acid with restraint stress. Then the pharmacokinetics of berberine in the rat plasma were compared after oral administration of berberine hydrochloride (25 mg/kg) to normal rats and PI-IBS rats. Quantification of berberine in the rat plasma was achieved by using a sensitive and rapid UPLC-MS/MS method. Plasma samples were collected at 15 different points in time and the pharmacokinetic parameters were analyzed by WinNonlin software. Compared with the normal group, area under the plasma concentration vs. time curve from zero to last sampling time (AUC_0–t) and total body clearance (CL/F) in the model group significantly increased or decreased, (2039.49 ± 492.24 vs. 2763.43 ± 203.14; 4999.34 ± 1198.79 vs. 3270.57 ± 58.32) respectively. The results indicated that the pharmacokinetic process of berberine could be altered in PI-IBS pathological conditions.     

Protein A Detection Based on Quantum Dots-Antibody Bioprobe Using Fluorescence Coupled Capillary Electrophoresis

In this report, fluorescence detection coupled capillary electrophoresis (CE-FL) was used to detect Protein A. Antibody was first labeled with Cy5 and then mixed with quantum dots (QDs) to form QDs-antibody bioprobe. Further, we observed fluorescence resonance energy transfer (FRET) from QDs donor to Cy5 acceptor. The bioprobe was formed and brought QDs and Cy5 close enough to allow FRET to occur. After adding protein A, the FRET system was broken and caused the FRET signal to decrease. Thus, a new method for the determination of protein A was proposed based on the FRET signal changes. This study provides a new trail of thought for the detection of protein.     

建筑工程中外墙保温技术应用

本文对建筑工程中外墙保温技术的应用进行分析,探讨外墙保温技术的应用状况及特点,为该种新型节能技术的有效应用提供有价值的参考。     

关于工程施工的流水施工技术管理策略初论

工程施工中的流水施工技术源于工业生产中的“流水线作业法”,是一种理想的组织产品生产方法,其将工程项目建造过程分解成为若干个施工过程,并按照一定的顺序依次进行各个阶段的施工,从而完成整个施工工程,对工程施工的质量保证起到了重要的意义。     

浅谈房屋建筑工程软土地基施工方法

近几年房屋建筑工程的快速成长,对房屋建筑的软土地基施工方法的尺度和要求也愈来愈严酷,其中质量的分量是不容忽视。本文主要就房屋建筑工程软土地基施工方法进行了详细阐述。     

盛事之后——走向可持续发展的奥运场馆建设

本文根据国外现代奥运场馆建设实例提出,面对近期直接目标和长远间接目标的矛盾,奥运场馆建设必须根据举办城市的发展具体情况,确定各种效益的优先关系,在城市整体长远规划基础上,从节约化、续用化、生态化三方面指导奥运建设,落实可持续发展原则。