论有限责任公司股东退股权的正当性

有限责任公司在社会经济生活中,是公司类型中数量最多的一种,也是中小投资者所偏爱的投资组织形式,然而由于资本多数决原则和人合性特质,有限责任公司具有天然的封闭性,退股权作为破解这种封闭性的有效手段,具有存在的合理性和正当性.股东退股并非如大陆法系传统的公司法理论认为的那样无法和我国公司法的资本制度协调,随着资产信用理论取代资本信用理论以及公司契约论的流行,股东退股必将逐步得到公司法实务和理论界的认同.     

综放工作面快速回撤新工艺

本文首先通过FLAC2D数值模拟,证明了回撤方案的可行性。回撤工作面的顶板采用锚带网和锚索联合支护,在保证回撤安全的基础上,减少人力和材料的应用,节省回撤时间,具有很大的经济技术意义,对本矿和其他矿井综放工作面的回撤具有一定的指导意义。     

国有资本完全退出竞争性领域刍议

在理论界,许多人认为国企应该完全退出竞争性领域;在实践中,许多地方也是以国企如何能够快速、大规模地退出为目标。笔者认为,依目前的国情以及国内外的经验看,这种方式并不适宜。国企依然有其存在的价值,仍须在竞争性领域站稳脚跟,继续承担促进中国产业发展的责任。     

一种适用于Ad hoc网络的轻量级密钥交换协议

通过对Ad hoc网络安全性特殊需求的分析,提出适合其特点的轻量级节点间密钥交换协议. 协议使用一种新的基于ID的身份认证机制相互验证身份;使用改进的Blom机制生成加密密钥和认证密钥,分别用于数据私密性保护和报文完整性检查. 为了防止敌方捕获密钥,提出基于节点间数据流的密钥更新机制. 针对节点撤销,给予相应的解决方案. 从不同的角度对协议进行安全性分析,通过和其他实现方法比较,在性能方面证明其高效性.     

血管钳持针柄静脉直刺法减轻疼痛的观察

目的：寻找静脉穿刺及拔针时减轻患者疼痛及减少对组织血管损伤的方法。方法：采用自身对照法,单日采用传统穿刺及拔针法,双日采用改良直刺及拔针法。结果：改良法较传统法疼痛程度减轻（P〈0．01）;一次穿刺成功率显著提高（P〈0．01）;拔针后血管周围淤血、出血、液体渗漏、静脉的损伤程度显著降低（P〈0．05）。结论：用血管钳持针柄直刺法,针尖斜面对血管组织的机械切割面积小,速度快,省力,稳定度高,提高穿刺成功率,配合改良拔针法,能有效减轻疼痛,降低并发症。     

对网络学术出版整合的思考

随着计算机、网络技术的发展,学术传播环境发生了翻天覆地的变化,基于网络的学术出版体系正在形成和发展中。我国的网络学术出版主要有以下几种形式:1.基于纸质文献的数字化而建立起来的学术文献数据库;2.研究者与学术研究团体建立的学术网站;3.学者的个人博客;4.电子预印本数据库。目前,网络学术出版也存在以下几个问题:1.搜索和保存问题;2.版权保护问题;3.身份认同问题。建议建立综合性的开放存取式的网络学术信息交流平台。     

Opioids and behavior: genetic aspects

Summary Three animal models, based on genetic differences in endogenous opioid peptides and opioid receptors, are described. Obese mice and rats, whose pituitary opioid content is elevated, may be used to investigate eating disorders. Recombinant inbred strains of mice, which differ in brain opioid receptors and analgesic responsiveness, can be used for study of opioid-and nonopioid-mediated mechanisms of pain inhibition. Individual reactivity to opioids can be examined in C57BL/6 and DBA/2 inbred strains of mice. A model that combines a variety of opioid effects is offered and suggests the existence of a genetically determined dissociation of opioid effects on locomotor activity and pain inhibition. In addition, stimulatory locomotor responses in the C57BL/6 reaction type are linked to a high risk of drug addiction and facilitatory effects on adaptive processes, while high analgesic potency in the DBA/2 reaction type is accompanied by a low proneness to drug abuse and amnesic properties of opioids.     

On the renal inner medullary concentration of sodium

Summary The principle of central volume is applied to the sodium and water contents of the inner medulla of the mammalian kidney. The analysis raises questions about the possibility of concentrating sodium ions in the inner medulla by a mechanism that postulates, in the same tissue segment, water withdrawal from the descending thin limb of the loop of Henle and sodium entry from the ascending thin limb.     

Ethanol and opioid receptor signalling

Summary Ethanol may modulate endogenous opioid systems by disrupting opioid receptor signalling. Low concentrations of ethanol slightly potentiate -opioid receptor binding by increasing receptor B_max, and, in some cases, chronic ethanol exposure decreases the density or affinity of the -opioid receptors. By contrast, high concentrations of ethanol acutely decrease -opioid receptor binding by decreasing receptor affinity, whereas chronic exposure of animals and neuronal cell lines to lower concentrations of ethanol leads to possibly adaptive increases in the density or affinity of the -opioid receptors. In the neuronal cell line NG108-15, ethanol does not up-regulate the -opioid receptor by blocking receptor degradation or endocytosis, but protein synthesis is required for this response. Up-regulation of the -opioid receptor renders ethanol-treated NG108-15 cells 3.5-fold more sensitive to opioid inhibition of adenylyl cyclase. Long-term treatment with ethanol also increases maximal opioid inhibition in NG108-15 cells, possibly by decreasing levels of G_s and its mRNA. Ethanol differentially modulates signal transduction proteins in three additional neuronal cell lines, N18TG2, N4TG1, and N1E-115. Ethanol-treated N18TG2 cells show the least up-regulation of the -opioid receptor, little heterologous desensitization of adenylyl cyclase, and no changes in G_s or G_i. By contrast, ethanol-treated N1E-115 cells show the largest up-regulation of the -opioid receptor, the most heterologous desensitization of adenylyl cyclase, and concentration-dependent decreases in G_s and increases in G_i. Further analysis of these related neuronal cell lines may help to identify the molecular elements that endow some, but not all, neuronal cells with the capacity to adapt to ethanol.