Cardioprotective activity of synthetic guggulsterone (E and Z-isomers) in isoproterenol induced myocardial ischemia in rats: A comparative study

Guggulsterone, a mixture of cis (E) and trans (Z) isomers (7∶3 w/w) was synthesized from 16-DPA. The isomers were separated by column chromatography and evaluated for cardioprotective and antioxidant activities. Myocardial necrosis induced by isoproterenol in rats caused marked increase in serum creatine phosphokinase and glutamate pyruvate transaminase. Simultaneously in ischemic heart, phospholipase, xanthine oxidase and lipid peroxides were enhanced following depletion of glycogen, phospholipids and cholesterol. Treatment with guggulsterone and its both isomers at the dose of 50 mg/kg po., significantly protected cardiac damage as assessed by the reversal of blood and heart biochemical parameters in ischemic rats. The cardioprotective activity of guggulsterone and of both the isomers were compared with that of gemfibrozil at the same doses. Guggulsterone and both the isomers at tested concentrations (5–20mM) inhibited oxidative degradation of lipids in human low-density lipoprotein and rat liver microsomes induced by metal ionsin vitro. The drug counteracted against the generation of superoxide anions (O₂) and hydroxyl radicals (OH⁻) in non-enzymic test systems. It is suggested that cardioprotective and antioxidant activities of synthetic guggulsterone and guggulsterone obtained from gum resinCommiphora mukul that contains isomers E & Z in the ratio of 46∶54w/w are the same.     

从白金预认证到三星级:中美绿色建筑分等评级程序的比较分析

2011年,作为全球最大能源使用国以及二氧化碳排放国,中美的建筑业所消耗的能源分别占到全国能源总消耗量的25%和40%。在建筑节能领域,绿色建筑的出现为消除建筑业所带来的对能源以及环境的负面影响提供了解决方法。为了促进绿色建筑的市场转型,推进设计和施工的差异化,中美均制定了国家绿色建筑分等评级程序以及配套政策。1998年,美国绿色建筑协会首次推出能源与环境先导设计(LEED),而中国政府则于2008年建立了中国绿色建筑评价标识(GBEL)。本文对美国LEED与中国GBEL评级程序、流程、评分系统以及扶持政策作了对比分析,研究发现,虽然两国所采用的绿色建筑设计以及操作评级程序的评分等级较为相似,它们在项目管理、评分要求和分配以及扶持政策类型等方面存在差异。美国能源与环境先导设计是由建筑产业利益相关者委员会制定并实施管理的。判断是否达到认证水平的灵活性更高。中国绿色建筑评价标识则是由政府操控的。判断是否达到评级水平的要求更为严格。但是,中国政府将在2014年下半年对中国绿色建筑评价标识的评级程序作出修正。本文对评级程序以及扶植政策的相似点以及差异是如何影响绿色建筑技术以及市场的发展作了分析,还讨论了绿色建筑未来发展可能面临的挑战以及政策导向意义。     

Modulation of convulsive threshold of pentylene tetrazole by zinc

In the present study which was aimed to see the effect of zinc on pentylenetetrazole induced convulsive threshold in rats we found that zinc sulfate 100 μg intracerebroventricularly) and pentylenetetrazole (50 mg/kg intraperitoneally) produced dose related seizure activity; however, pretreatment with zinc decreased the threshold, increased the severity, incidence of multiple seizures and total duration of pentylenetetrazole induced seizures. Diazepam (5 mg/kg intraperitoneally) pretreatment increased the threshold and lowered the incidence of convulsions in zinc induced seizures which further confirms that the convulsive effect of zinc is through inhibition of gamma aimino butyric acid.     

Racing behavior technological evolution in the high-end computer industry

In a thirty-year period, firms in the high-end computer industry compete for technological leadership with select subgroups of firms. A clustering technique is used to identify these subgroups of firms. In each of the three such ‘races’ that I identify, a firm's racing rivals influence the evolution of its own technology frontier. This approach complements life-cycle and other models of technological evolution. A central role is assigned to strategic interactions between firms. Different kinds of strategic interactions lead to intra-race and inter-race behavior. I demonstrate how such inter-firm interactions map into technological evolution at the industry level and suggest that the patterns seen here can help us understand technological evolution in a range of environments.     

Antioxidant and lipid lowering activities of Indian black tea

Indian black tea; CTC leaf and dust, produced by Tata Tea Limited, Kolkata, (India) was studiedin vitro as potential scavenger of oxygen free radicals. Super oxide anions were generated in a system containing xanthine—xanthine oxidase (enzymic system) and by NADH- phenozine methosulphate (non enzymic system). Anions were assayed in terms of uric acid formation and reduction of nitroblue tetrazolium salt, which were shown to be suppressed by tea extracts. Extracts from both leaf and dust also inhibted the formation of hydroxyl radicalsin vitro in the enzymic system comprising hypoxanthine—Cu⁺²—sodium ascorbate and xanthine oxidase and in non enzymic system of deoxyribose—Cu⁺²—sodium ascorbate and H₂O₂ as well as the Cu⁺² induced lipid peroxidation in human low density lipoprotein. Feeding with black tea in normal rats for sixty days increased their antioxidant activity and their liver microsomes were shown to be protected against peroxidation of lipids as stimulated by metal ions with enzymic or non enzymic reactants. Furthermore feeding with tea extracts in normal as well as triton WR—1339 induced hyperlipidemic rats caused decrease in their plasma levels of total cholesterol, phospholipids and triglycerides. The antioxidant and lipid lowering activities of both extracts from CTC leaf and dust tea was comparable and may be due to the presence of natural products like catechin and others.     

Change in Student Perceptions of Course and Instructor Following Curriculum Change

Ongoing curriculum change in higher education is essential to enhance student learning and better prepare them for the job‐market. However, research shows that faculty are reluctant to implement such changes because students generally react adversely thereby negating any potential benefits, and moreover, sanction faculty through lower evaluations and future enrollment. Yet, understanding of the effect of curriculum changes on students’ course and instructor perceptions is limited. In this article we attempt to fill this gap. Drawing on two empirical findings—students’ motivation to attend college becoming increasingly extrinsic since the 1960s and their inability to recognize, ex ante, the value‐added by a curriculum change—and the norm life‐cycle theory, we argue that any effort‐increasing or grade‐threatening change is viewed as non‐normative and will lead to an adverse student reaction. However, this adverse reaction will dissipate over time once a critical mass of students is convinced of the merits of the new curriculum. We find support for our hypotheses by analyzing change in student perceptions following curriculum changes at a U.S. University. In addition, we also find that once the adverse reaction dissipates, students’ perceptions of the new curriculum become more positive than the old curriculum, only to be reversed once the revised curriculum is accepted as the new norm.     

A conceptual framework for achieving good governance at open and distance learning institutions

This paper describes a good governance architecture framework that would bring significant improvements in the overall working of open and distance learning institutions in a well-structured and systematic way. The good governance framework is articulated with seven basic principles which are performance, transparency, accountability, participation, leadership, consensus orientation and fairness. These principles are structured with the good governance practices which relate to performing well for the assigned goals and objectives, promoting values for the organisation, making well-informed and transparent decisions, focusing on the organisation’s purpose and outcomes, capacity building and managing risks effectively. These principles and suggested practices in the framework would become tools for developing an improvement strategy so as to help in the smooth operation and efficient management of the institution concerned. The developed system would bring about significant improvement in the teaching–learning activity as well as in the quality of distance education. It would also enhance the efficiency, effectiveness and overall performance of the institutional management which is crucial to the continuous development of the institution concerned. Thus, the proposed good governance framework when implemented in an open and distance education institution would improve the quality of distance education and also increase its accessibility in a well-organised and structured way.     

Changing Dynamics of a Manufacturing Unit

This article describes a performance improvement project undertaken in the manufacturing unit of a multinational company in India that specializes in the business of engineering, procurement, and construction (EPC). The article includes a brief introduction to the company's business (leaving out the name of the company due to a clause of confidentiality). The objective of the article is to describe a set of performance problems and how various performance theories, models, and tools were used to identify root causes and to implement design solutions for improvement. The article describes how the author as an internal consultant employed various consulting principles to establish a strong platform of understanding and to build a partnership with the clients. In addition, the different stages used in analyzing the problem, applying performance models, and designing solutions are presented. The article concludes with the author's sharing his personal experiences and the feedback he received from project stakeholders.