The effect of Emetine on macromolecular synthesis in synchronizedTetrahymena pyriformis

Zusammenfassung Emetin hemmt die synchronisierte Teilung vonTetrahymena pyriformis, verhindert die rasche Aufnahme von Aminosäuren und verursacht offenbar eine Zellteilungshemmung.

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This work was supported in part by grants from the Hawaii Heart Association and the Julius and Dorothy Fried Foundation.     

煤中微量元素和矿物富集的同沉积火山灰与海底喷流复合成因

煤中常量、微量元素和矿物的富集往往是多种地质因素共同作用的结果. 运用低温灰化、X射线衍射分析、带能谱仪的扫描电子显微镜、逐级化学提取、电离耦合等离子体质谱等方法对云南砚山晚二叠世煤的矿物学和地球化学特征进行了研究, 提出了煤中微量元素和矿物富集的同沉积火山灰与海底喷流复合模式(或成因类型). 研究发现, 砚山矿区M9煤层硫分含量很高(S_t,d = 10.65%), 属于超高有机硫煤(S_o,d = 9.51%). 矿物组成主要有b-石英副像、透长石、钠长石、白云母、伊利石、黄铁矿以及少量的高岭石、斜长石、钙镁黄长石、金红石和片钠铝石. 煤中高度富集的微量元素有F(841 μg/g), V(567 μg/g), Cr(329 μg/g), Ni(74 μg/g), Mo(204 μg/g)和U(153 μg/g). 该煤中的矿物质主要有3个来源: (1) 高温石英、透长石、白云母和伊利石等是泥炭聚积期间酸性火山灰降落到泥炭沼泽后的产物; (2) 钠长石和片钠铝石以及以上超常富集的微量元素是在泥炭聚积期间, 基性-超基性海底喷流侵入到闭塞缺氧的泥炭沼泽中所致; (3) 稀土元素, Nb, Y, Zr和TiO₂等亲石元素来源于盆地南部的越北古陆. 除了物源供给以外, 砚山矿区煤的矿物学和地球化学异常是同沉积酸性火山灰和基性-超基性海底喷流共同作用的结果.     

循环赛图K(i)2n与边矩阵K''''2n的K-边着色

为了让一个2n阶的完全图K2n变成一个可用于循环赛安排的循环赛图K(i)2n,给出了边矩阵和循环赛图的定义,提出了利用边矩阵K'2n的k-边着色求求解完全图K2n的k个完备匹配Mi的算法.介绍了循环赛图K(i)14,K(i)16,…,K(i)32的构造结果及其应用.     

Dependence of 6β-acetoxy-7α-hydroxyroyleanone block of Kv1.2 channels on C-type inactivation

Voltage-gated K⁺ (Kv) channels exhibit slow or C-type inactivation during continuous depolarization. A selective pharmacological agent targeting C-type inactivation is hitherto lacking. Here, we report that 6β-acetoxy-7α-hydroxyroyleanone (AHR), a diterpenoid compound isolated from Taiwania cryptomerioides, can selectively modify C-type inactivation of Kv1.2 channels. Extracellular, but not intracellular, AHR (50 μM) dramatically accelerated the slow decay of Kv currents and left-shifted the steady-state inactivation curve. AHR blocked Kv currents with an IC₅₀ of 17.7 μM. AHR did not affect the kinetics and voltage-dependence of Kv1.2 channel activation. Channel block by AHR was independent of intracellular K⁺ concentration. In addition, effect of AHR was much attenuated in a Kv1.2 V370G mutant defective in C-type inactivation. Therefore, block of Kv1.2 channels by AHR did not appear to involve direct occlusion of the outer pore but depended on C-type inactivation. AHR could thus be a probe targeting Kv channel C-type inactivation gate.     

死亡权:安乐死立法的价值基础

目前,绝症病人的死亡权问题已成为国际性话题。和死亡权密切相关、争论最为激烈的问题是安乐死立法。表面看来,安乐死不但违背了尊重生命的直觉,也似乎公然侵犯了最基本的人权——生命权,因为人们常常把生命简单地等同于生存,把死亡理解为生命结束后的状态即和生存无关的无生命状态。其实,死亡和生存是贯穿生命始终的生命自身的本质规定。因此,生命权是生存权和死亡权的统一,死亡权是生命权的应有之义。这就奠定了安乐死立法的价值基础。     

聚含氟丙烯酸酯/蒙脱土复合乳液的制备及性能研究

以丙烯酸六氟丁酯(HFBM)为功能性单体,蒙脱土为改性剂,采用间歇式乳液聚合法合成了聚含氟丙烯酸酯/蒙脱土复合乳液,用红外光谱(FT-IR)、热重分析(TG)和X-射线衍射(XRD)对其结构进行了表征,并研究了复合乳化剂的配比、引发剂用量、含氟单体用量和蒙脱土含量对乳液聚合反应的影响,同时探讨含氟单体含量和有机蒙脱土含量对力学性能的影响.结果表明,季铵盐通过离子交换作用进入到蒙脱土层间,层间距由1.6 nm增加至2.2 nm;当m(十二烷基硫酸钠):m(曲拉通X-100)=3:2,引发剂用量为1wt%,含氟单体为9wt%时,具有较大的单体转化率(90.42%)和较小的凝胶率(0.72%);HFBM含量为9wt%,有机蒙脱土为2wt%时,乳胶膜有较大的拉伸强度为12.33 MPa.     

在Diels-Alder反应中一种新的二烯──1─(2-丁二烯基)吡啶溴化物

１－（３－二无氧化硫杂环戊－３－烯基）吡啶溴化物（４）作为新的带正电荷的二烯（６）的稳定的前体，它与一些缺电子的亲双烯体发生［４＋２］环加成反应。     

Software technology for e-commerce era

The rapid growth of Internet usage and electronic commerce (e-commerce) applications will push traditional industries to transform their business models and to re-engineer their information systems. This direction will give the software industry either great opportunities for their business growth or crucial challenges to their existence. This article describes two essential challenges the software industry will face and presents relevant new technologies that will be helpful for overcoming those challenges.