丹参酮ⅡA的药理研究进展

对近年来丹参酮ⅡA药理作用研究最新进展进行总结,包括抗肿瘤,对心血管的药理作用,抗肝纤维化、护肝和抗肝癌作用,性激素样活性,抗炎作用等,其多方面药理作用,值得进一步研究开发.     

重齿鳞毛蕨中总黄酮的含量测定

黄酮类化合物具有抗癌、抗氧化、抗炎、保肝护肝、调节免疫等药理作用,一直受到国内外研究人员的高度重视。研究采用分光光度法测定了重齿鳞毛蕨(Dryopteris juxtaposita)中总黄酮的含量,并研究了提取试剂种类、试剂浓度、料液比、提取时间对总黄酮提取率的影响。结果表明采用体积分数75%乙醇加热回流180min,料液比为1g∶12mL时提取液中总黄酮提取率最高,其平均提取率为1.056%。由于此含量测定方法准确度高,操作简单,因此可作为一种高效便捷测定重齿鳞毛蕨中总黄酮含量的方法。     

重齿鳞毛蕨中总黄酮的含量测定

黄酮类化合物具有抗癌、抗氧化、抗炎、保肝护肝、调节免疫等药理作用,一直受到国内外研究人员的高度重视。研究采用分光光度法测定了重齿鳞毛蕨(Dryopteris juxtaposita)中总黄酮的含量,并研究了提取试剂种类、试剂浓度、料液比、提取时间对总黄酮提取率的影响。结果表明采用体积分数75%乙醇加热回流180min,料液比为1g∶12mL时提取液中总黄酮提取率最高,其平均提取率为1.056%。由于此含量测定方法准确度高,操作简单,因此可作为一种高效便捷测定重齿鳞毛蕨中总黄酮含量的方法。     

重齿鳞毛蕨中总黄酮的含量测定

黄酮类化合物具有抗癌、抗氧化、抗炎、保肝护肝、调节免疫等药理作用,一直受到国内外研究人员的高度重视。研究采用分光光度法测定了重齿鳞毛蕨(Dryopteris juxtaposita)中总黄酮的含量,并研究了提取试剂种类、试剂浓度、料液比、提取时间对总黄酮提[WT]取率的影响。结果表明采用体积分数75％乙醇加热回流180 min,料液比为1 g∶12 mL时提取液中总黄酮提取率最高,其平均提取率为1.056%。由于此含量测定方法准确度高,操作简单,因此可作为一种高效便捷测定重齿鳞毛蕨中总黄酮含量的方法。 〖HJ4mm〗     

红参活性成分及其在化妆品中作用的研究进展

为红参在化妆品应用中的研究与开发提供参考,查阅近些年国内外关于红参的文献,并对相关文献进行分类与整理。研究发现红参在加工过程中会产生除与鲜参、生晒参共有的成分外,还会生成多种特有的活性成分,如:人参皂苷Rg₃、人参皂苷Rh₁、人参皂苷Rh₂、红参多糖、精氨酸双糖苷、麦芽酚等,使红参的某些药理作用增强,让红参具有抗衰老、美白等化妆品功效。红参有多种生物活性成分与药理作用,在化妆品开发与研究中具有良好的应用前景。     

川续断化学成分及药理作用研究进展

本文对川续断化学成分以及药理作用的研究概况进行了综述《,神农本草经》曾经记载植物川续断具有治疗跌打损伤的作用,现代药理研究认为川续断的药理作用在于增强免疫力和抗氧化。     

重点推介项目目录（二）

【项目名称】9-氨基八氢吖啶琥珀酸盐-用于治疗老年性痴呆及脑血栓等原料及片剂 本项目的主要药理作用是有选择地抑制脑中乙酰胆碱酯酶活性，相应增加脑内神经突出间乙酰胆碱含量，将产生记忆和处理信息的主要区域（海马区、脑皮质和杏仁体）与基底部脑区相联系，能够较好地穿透血脑屏障，通过抑制乙酰胆碱酯酶在神经腱内浓缩乙酰胆碱并能保持较长的作用时间，它的药理作用机制在于对细胞膜的钾通道一定亚型有选择的封闭和对乙酰胆碱酯酶的抑制作用，系双重胆碱酯酶抑制剂。     

玛咖酰胺及玛咖烯的研究进展

玛咖酰胺和玛咖烯是玛咖中特有的成分,玛咖酰胺具有多种药理活性,其含量已作为检测玛咖质量优劣的标准。文章从提取、合成、检测及药理作用等方面对玛咖酰胺和玛咖烯的研究现状进行了综述,以期为深入研究玛咖酰胺和玛咖烯提供参考。     

鹿茸多肽组分药理作用的研究进展

鹿茸多肽组分是鹿茸中重要的生理活性物质,其具有免疫调节,抗肿瘤,促进组织愈合和修复,抗氧化、抗疲劳,促神经细胞再生及功能恢复等多种药理作用.本文总结了鹿茸多肽的最新研究进展,提示其临床应用前景广泛,为进一步开发、利用这一道地中药材提供参考依据.     

积雪草的化学成分分析及药理作用研究进展

积雪草作为一种比较常见的中药,具有非常广泛的药理作用,应用空间非常广阔,应不断加强对积雪草的研究分析,充分利用积雪草所具有的功效,加强在各领域的应用,有效提高临床治疗的效果.本文主要就积雪草所含的化学成分进行简要分析,综述积雪草药理作用的研究状况,为积雪草的进一步研究提供参考.     

The impact of market actions on firm reputation

Drawing on signaling theory, we hypothesize that a firm's reputation is shaped by its own market actions and the actions of its industry rivals. We view market actions as signals that convey information about the underlying competencies of firms and influence stakeholder evaluations of them. We find that the total number of a firm's market actions, the complexity of its action repertoire, the time lag in rivals' responses to its actions, and the similarity of its repertoire with those of its rivals positively affect its reputation. These results suggest that a firm's reputation is influenced both by its own actions and by its rivals' actions. Copyright © 2006 John Wiley & Sons, Ltd.     

Understanding the impact of symbolic and substantive environmental actions on organizational reputation

Research in corporate environmental practices has shown that stakeholders impose coercive and normative forces that drive firms to perform environmental protection actions. However, limited attention has been placed on how different constituents of stakeholders value the firm's environmental actions. By focusing on industry peers as a constituent of stakeholders, we examine how the firm's environmental actions impact its reputation. Based on institutional theory and signaling theory we propose that symbolic environmental actions negatively affect reputation, whereas substantive actions improve firm's reputation among its peers. Building on the notion of signaling process, the authors also observe that a firm's reporting practices moderate positively the negative effect of symbolic actions. Data from a sample of 213 publicly traded firms operating in polluting industries from 2006 to 2013 support these results. The findings emphasize the danger of using symbolic actions to signal environmental commitment in a context of high-involvement information search and opportunistic behaviors.     

Software firm turnarounds in the 1990s: An analysis of reversing decline in a growing,dynamic industry

Investigations into management actions that reverse organizational decline have produced inconsistent findings. Prior studies have focused on the value of retrenchment actions versus strategic actions to engineer a performance turnaround. These studies, however, have generally not controlled for the cause of firm decline, overlooking a major theoretical contingency. Examining prepackaged software firms in the 1990s, we test the association of strategic and retrenchment actions in facilitating turnarounds in a munificent industry. The results show that measures of strategic actions—new product introductions, strategic alliances, and acquisitions—were positively associated with turnarounds. Conversely, measures of retrenchment actions—layoffs, asset reductions, and product withdrawals—were negatively associated with performance recovery. Our results suggest declining firms in munificent industries cannot retrench their way back to prosperity. Copyright © 2013 John Wiley & Sons, Ltd.     

Believing one's own press: the causes and consequences of CEO celebrity

This theoretical article introduces the construct of CEO celebrity in order to explain how the tendency of journalists to attribute a firm's actions and outcomes to the volition of its CEO affects such firm. In the model developed here, journalists celebrate a CEO whose firm takes strategic actions that are distinctive and consistent by attributing such actions and performance to the firm's CEO. In so doing, journalists over‐attribute a firm's actions and outcomes to the disposition of its CEO rather than to broader situational factors. A CEO who internalizes such celebrity will also tend to believe this over‐attribution and become overconfident about the efficacy of her past actions and future abilities. Hubris arises when CEO overconfidence results in problematic firm decisions, including undue persistence with actions that produce celebrity. Copyright © 2004 John Wiley & Sons, Ltd.     

Market reactions to announcements of corporate downsizing actions and implementation strategies

This study examines the effects of downsizing actions and implementation strategies on market performance. While downsizing actions reduce costs, they also produce a loss of valuable human capital that can exceed the benefits resulting from the lay‐offs. In support of this argument, the results showed that downsizing had a negative effect on market returns and the effects grow increasingly negative with larger downsizing actions. However, the market reacts more positively to downsizing actions when reallocation strategies are used and to large downsizing actions when disengagement incentives are applied. The results of this research suggest the importance of carefully managing valuable resources to create positive returns. Copyright © 2004 John Wiley & Sons, Ltd.     

Mind the gap: The interplay between external and internal actions in the case of corporate social responsibility

Research summary : We explore the effect of the interplay between a firm's external and internal actions on market value in the context of corporate social responsibility (CSR). Specifically, drawing from the neo‐institutional theory, we distinguish between external and internal CSR actions and argue that they jointly contribute to the accumulation of intangible firm resources and are therefore associated with better market value. Importantly, though, we find that, on average, firms undertake more internal than external CSR actions, and we theorize that a wider gap between external and internal actions is negatively associated with market value. We confirm our hypotheses empirically, using the market‐value equation and a sample comprising 1,492 firms in 33 countries from 2002 to 2008. Finally, we discuss implications for future research and practice. Managerial summary : Companies often accumulate intangible assets by taking internally and externally oriented CSR actions. Contrary to popular beliefs, the data show that they undertake more internal than external ones: firms do more and communicate less. How does a potential gap (i.e., a misalignment) between internal and external CSR actions affect a firm's market value? We find that although together (the sum of) internal and external actions are positively associated with market value, a wider gap has negative implications. In other words, firms do not realize the full benefits of their internal actions when such actions are not externally communicated to key stakeholders, and to the investment community in particular. This negative association with market value is particularly salient in CSR‐intensive and the natural resources and extractives industries. Copyright © 2015 John Wiley & Sons, Ltd.     

Strategic action and customer mobility: Antecedents and consequences of strategic actions in the Korean mobile telecommunication service industry

This paper investigates the sources and consequences of strategic actions in the Korean mobile telecommunication service industry. Based on competitive dynamics research and an organizational learning perspective, it suggests hypotheses and tests them with monthly data on service providers’ competitive and alliance actions, as well as statistics on monthly subscribers during 2002–2007. We show the positive effects of a firm’s own experience, other firms’ strategic actions, and firms’ alliance tendencies on the likelihood of firm-level competitive action and alliance. We also find that negative performance feedback accelerates the mimetic influence of rival firms’ competitive actions and that positive performance feedback strengthens the momentum effect of a firm’s own alliance experience on the likelihood of alliance. Both competitive actions and alliances appear to influence customer mobility across firms in a complex manner. Based on customer mobility data, this study finds that alliances increase market dynamism, that is, customer mobility. It also shows that competitive actions, in general, serve to effectively attract switching customers from rivals. This study partially answers questions regarding the triggers of competitive actions and alliance activities among mobile telecommunication service providers and their performance consequences.     

Legitimizing actions in dependence-asymmetry relationships: A comparison between Chinese and Western firms

To overcome the negative outcomes of dependence, disadvantaged parties in exchange relationships characterized by dependence asymmetry seek effective strategies to rebalance their dependence. Obtaining legitimacy in the eyes of the advantaged party through legitimizing actions is a novel way to influence the advantaged party's exchange and conflict management approaches toward the disadvantaged party. However, a disadvantaged party's preference between external and internal legitimizing actions varies across cultures because culture influence the character if the relationship management preference. Drawing on the individualism–collectivism framework, we argue that facing dependence asymmetry, a Chinese firm is more likely to seek legitimacy through external legitimizing actions than a Western firm. In contrast, a Western firm is more likely to seek legitimacy through internal legitimizing actions than a Chinese firm when facing dependence asymmetry. We also predict a positive relationship between legitimizing actions, both external and internal, and the disadvantaged party's performance. We test these hypotheses by collecting dyadic survey data of exchange partners in Chinese-owned and Western-owned firms. The results support most of our predictions. Theoretical and managerial implications for partners in dependence-asymmetric relationships are discussed based on these findings.     

THE SIMPLICITY OF COMPETITIVE REPERTOIRES: AN EMPIRICAL ANALYSIS

This research explores the notion of competitive simplicity: a tendency of some firms to concentrate intensely on just a few central activities. Our focus here is the simplicity inherent in the repertoire of concrete, market-oriented actions used by companies to compete: these actions include product introductions, pricing or advertising decisions, and changes in market scope. The simplicity of a competitive repertoire can be assessed by its range of actions and its degree of concentration on one or a few dominant types of actions. We argue that competitive simplicity is largely a function of organizational and environmental properties that attenuate managerial search or restrict knowledge of competitive alternatives. These properties include good performance, munificent, homogeneous or certain markets, a lack of breadth in competitive experiences, and the complacency that may accompany age and size. Paradoxically, although good past performance may contribute to simplicity, simplicity can hurt subsequent performance, especially during periods of uncertainty and growth. Many of these ideas were borne out in a study of the major carriers of the post-deregulation domestic airline industry.     

Competitive behavior in the European mobile telecommunications industry: Pioneers vs. followers

This paper studies the relationship between competitive strategy and improvement in the competitive position of pioneers and followers in the mobile telecommunications industry. The analysis uses a panel of data comprising all the actions of European firms operating in the digital mobile telecommunications industry with GSM 900 and/or DCS 1800 networks. The results show that competitors gain market share when they follow competitive strategies that are different from those of other firms. The paper also finds that price reduction actions represent the best approach for followers, while differentiation actions are the most effective strategy for pioneers.