Characterization of the human cysteinyl leukotriene CysLT1 receptor.

The cysteinyl leukotrienes-leukotriene C4(LTC4), leukotriene D4(LTD4) and leukotriene E4(LTE4)-are important mediators of human bronchial asthma. Pharmacological studies have determined that cysteinyl leukotrienes activate at least two receptors, designated CysLT1 and CysLT2. The CysLT1-selective antagonists, such as montelukast (Singulair), zafirlukast (Accolate) and pranlukast (Onon), are important in the treatment of asthma. Previous biochemical characterization of CysLT1 antagonists and the CysLT1 receptor has been in membrane preparations from tissues enriched for this receptor. Here we report the molecular and pharmacological characterization of the cloned human CysLT1 receptor. We describe the functional activation (calcium mobilization) of this receptor by LTD4 and LTC4, and competition for radiolabelled LTD4 binding to this receptor by the cysteinyl leukotrienes and three structurally distinct classes of CysLT1-receptor antagonists. We detected CysLT1-receptor messenger RNA in spleen, peripheral blood leukocytes and lung. In normal human lung, expression of the CysLT1-receptor mRNA was confined to smooth muscle cells and tissue macrophages. Finally, we mapped the human CysLT1-receptor gene to the X chromosome.     

乙酸和正丁醇在强酸性阳离子交换树脂上酯化反应的动力学行为

以大孔强酸性阳离子交换树脂为催化剂进行了乙酸和正丁醇的酯化反应，研究了不同的催化剂用量、醇／醇摩尔比和温度对酯化反应的影响，得出较佳的工艺条件为２．５２ｇｃａｔ／ｍｏｌＨＡｃ、醇／酸摩尔比为１和１１０～１２０℃，并从温度与酯化速度的关系求出反应级数（ｎ），反应速度常数（ｋ）和反应活化能（Ｅ）．     

Diatom-based reconstruction of Holocene environmental changes in Angren Lake, Southern Tibet

Based on the diatom analysis the climatic sequence between 11 000 and 6 000 aBP in Angren, southern Tibet is established, i.e. cold period (11 095-9 970 aBP)→temperate period (9 970-9 870 aBP)→Anathermal (9 870-9 770 aBP)→cool-dry period (9 770-8 740 aBP) →super-megathermal (8 740-8 590 aBP)→Megathermal (8 590-5 970 aBP). And the opinion that the reaction of diatom to temperature change is more sensitive than to other ecological factors has been pointed out and certified.     

崩滑体失稳破坏断裂力学分析

文章基于断裂力学分析,揭示了崩滑体破坏面裂纹尖端在应力场、外界因素作用下产生断裂扩展,其是崩滑体失稳的根本原因.计算归纳了滑动面的Ⅰ、Ⅱ型、复合型断裂强度因子和扩展角的计算方法,对有效治理崩滑体、防灾减灾有一定的指导意义.     

浅谈堤防工程沉箱施工技术

文章以沉箱技术在堤防施工中注意要点为研究对象,提出采用沉箱法开发建造水库围堤的方式,并通过对其中关键环节包括管段接头连接和接头止水等的分析论证,对在深水中筑造水库围堤在技术上的可行性进行了分析。     

中国原子弹研制中的风险问题初探

本文探讨了从风险视角出发研究中国原子弹工程的意义和优势,对中国原子弹工程中的风险构成要素(技术风险、军事风险和社会风险)进行了分析和论述,并围绕如何应对技术风险的问题,总结出三点成功经验,即权衡风险要素、强化资源配置和加强民主决策。     

震前特大地磁异常及其短临预警意义

对地磁记录分析的结果显示，大地震前强烈的地磁异常现象反复出现；在震中附近极震区临震前36 h至十几分钟，地磁场的特大异常数值随震级增大而增大。归算到距震中1 km处，Ms=6.0～9.5 级破坏性地震的磁场异常值约为102～105 nT，异常强度甚至超过地球磁场量级5.5×104 nT。根据其强度特性及时空分布，这种临震前在震中附近的ULF磁场异常，表现为一种“磁间隙喷发”。由此地磁异常的特性，提出利用大地震前短临地磁异常作为预警信号进行防震预警的探讨，由地磁预警突破目前地震预测预报难的现实困境，有望收到     

考虑年龄结构的女性模型

本文提出一种考虑年龄结构的离散人口模型，并进一步讨论这种模型的性质及其应用。     

HoNi2Ge2的X射线粉末衍射数据

给出尚未出现在ＪＣＰＤＳ－ＰＤＦ上的ＨｏＮｉ２Ｇｅ２相的Ｘ射线粉末衍射数据。该化合物属四方晶系，空间群为Ｉ４／ｍｍｍ，ａ＝４．０３０３（１），ｃ＝９．７７４５（４）。每个晶胞中有２个化合式量。衍射数据指标化可靠性因子Ｆ２９＝５４．６（０．００９３５７）。