Multiple respiratory gas monitoring causes changes of inspired oxygen concentration in closed anesthesia system

This case report describes an accessory hepatic duct (AHD) identified by intraoperative cholangiography during excisional surgery of a choledochal cyst (CC). The accessory duct was divided and reconstructed successfully to the Roux-en-Y jejunal loop. The postoperative course was uneventful, and follow-up abdominal sonography revealed neither evidence of biliary tract obstruction nor atrophic changes of the liver. It is advocated that an AHD should be meticulously reconstructed if it is divided during excisional surgery of a CC.     

连续重整装置仿真系统的设计开发

为提高操作人员对连续重整装置开停工及事故处理的熟练程度，并对生产进行指导，采用半机理模型结合设计和现场数据介发的连续重整装置仿真系统已在现场成功投用。介绍了该仿真系统的软硬件结构、动态模型及仿真功能。     

哈尔滨炼油厂MTBE装置试生产

介绍了哈尔滨炼油厂ＭＴＢＥ装置的工艺路线、新技术的应用及特点；催化剂的装填及应用情况；总结了生产过程中遇到的一系列问题及解决办法；探索了平稳生产的新徐径，以保证装置安全、平稳、长周期运行；同时对反应器操作温度、催化蒸馏塔操作压力、原料中醇烯比等因素对异丁烯转化率及ＭＴＢＥ产品的影响做了简单的总结。     

Abrasive wear of dental composite resins

Abrasive wear is a major problem in the application of dental composite resins. In this study the friction and wear behaviours of two types of dental composites: one containing relatively coarse filler particles and some microfillers (Estilux) and another containing only microfiller particles (Durafill), have been investigated by using a scratch testing machine. Experimental results show that the coefficients of friction in both composites are essentially constant for applied loads up to 20 N. The wear resistance of Durafill is better than Estilux. Under the same testing conditions, the size, shape and distribution of the filler particles are more important variables than applied load and sliding speed in controlling the wear mechanism. It is shown that for Estilux, plastic ploughing by the diamond indenter is the predominant mechanism. For Durafill, however, the formation and propagation of tensile cracks on the worn surface is the main wear mechanism. The effects of two different indenters, diamond and enamel, on the basic wear mechanisms are also discussed.     

太钢4号高炉喷煤站应用MFD—Ⅲ型布袋除尘器的实践

太钢４号高炉喷煤站从１９９０年起采用ＭＦＤ－Ⅲ型脉动反吹式布袋除尘器。这种除尘器采用脉动式反吹清灰设施，合理布置布袋间距，布袋支撑骨架及选用针呢材质的布袋，过滤面积大，反吹清灰效果好，设备运行平稳，除尘效率高达９９．８％，排放浓度小于１０ｍｇ／ｍ＾３，故障率低。     

LaCrMnNiO系热敏陶瓷的微观结构控制

通过对不同配方、工艺下的ＬａＣｒＭｎＮｉＯ系热敏陶瓷的微观结构研究，指出材料的相组成对其宏观电性能的影响，并提出了通过复合工艺利用“过渡相”的形成，对材料的“最终相”加以控制的方法。文中列出了使用ＸＲＤ及ＸＰＳ手段对材料微观结构的分析结果及有关电性能的测试数据。     

Inhibition of G1 cyclin-dependent kinase activity during growth arrest of human breast carcinoma cells by prostaglandin A2

Prostaglandin A2 (PGA2) potently inhibits cell proliferation and suppresses tumor growth in vivo, but little is known regarding the molecular mechanisms mediating these effects. Here we demonstrate that treatment of breast carcinoma MCF-7 cells with PGA2 leads to G1 arrest associated with a dramatic decrease in the levels of cyclin D1 and cyclin-dependent kinase 4 (cdk4) and accompanied by an increase in the expression of p21. We further show that these effects occur independent of cellular p53 status. The decline in cyclin D and cdk4 protein levels is correlated with loss in cdk4 kinase activity, cdk2 activity is also significantly inhibited in PGA2-treated cells, an effect closely associated with the upregulation of p21. Immunoprecipitation experiments verified that p21 was indeed complexed with cdk2 in PGA2-treated cells. Additional experiments with synchronized MCF-7 cultures stimulated with serum revealed that treatment with PGA2 prevents the progression of cells from G1 to S. Accordingly, the kinase activity associated with cdk4, cyclin E, and cdk2 immunocomplexes, which normally increases following serum addition, was unchanged in PGA2-treated cells. Furthermore, the retinoblastoma protein (Rb), a substrate of cdk4 and cdk2 whose phosphorylation is necessary for cell cycle progression, remains underphosphorylated in PGA2-treated serum-stimulated cells. These findings indicate that PGA2 exerts its growth-inhibitory effects through modulation of the expression and/or activity of several key G1 regulatory proteins. Our results highlight the chemotherapeutic potential of PGA2, particularly for suppressing growth of tumors lacking p53 function.     

高温超导研究的新进展

本文简要回顾了一年来高温超导的新进展，特别介绍和讨论了新型高温超导体系和线材、带材、块材及薄膜应用的发展情况。     

The mechanics of compressive kinking in unidirectional fiber reinforced ductile matrix composites

Three distinct stages of kink band formation and propagation exist in ductile matrix composites subjected to compressive loading. These stages are called incipient kinking, transient kinking and kink band broadening. Each stage involves a different deformation mode. The mechanics governing each stage are discussed. Incipient kinking, where the peak load is attained, and kink band broadening, where the load attains a steady-state, are important in structural design. Two design philosophies are presented. References to pertinent literature are made throughout.