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991.
Ramesh Chander Farhan Rizvi A. K Khanna Ram Pratap 《Indian journal of clinical biochemistry : IJCB》2003,18(2):71-79
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. 相似文献
992.
Bhanu P. Singh Banani Banerjee Puspanita Naik Jordan N. Fink Viswanath P. Kurup 《Indian journal of clinical biochemistry : IJCB》2006,21(2):20-27
The ubiquitous fungus Aspergillus fumigatus causes allergic rhinitis, asthma, sinusitis and allergic bronchopulmonary aspergillosis.
A number of major allergens from A. fumigatus are purified, but their structure-function role in the pathogenesis of disease
is not known. Such information is essential for devising alternative therapy of fungal allergic diseases. In the present study,
N-terminal and C-terminal deletion mutants ofAsp f 3 were constructed and their immunopathological responses studied in a mice model of allergy. Three mutants viz,Asp f 3 (aa 33–168), (aa 1–142), and (aa 23–142) were made by deleting certain amino acids from epitopic regions of full lengthAsp f 3, a major allergen of A. furnigatus. TheAsp f 3 and three mutated proteins were expressed in pET vector. The C-terminal deletion mutantAsp f 3 (aa 1–142) induced elevated IFN-γ but low levels of IL-4 by spleen cells. This mutant also showed significant downregulation
of peripheral blood eosinophils and lung inflammation in immunized mice. The N-terminal deletion mutantAsp f 3 (aa 33–168) also exhibited an immuno-suppressive effect in terms of IgE production and induction of Th2 cytokine. The results
indicate thatrAsp f 3 and its deletion mutants induced distinct immune-inflammatory responses in mice on challenge with these proteins. The non-IgE
binding deletion mutants ofAsp f 3 (aa 1–142 and aa 33–168) could deviate Th2 immune response with a concomitant reduction in airway inflammation and infiltration
of inflammatory cells. 相似文献
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996.
网上协作式数字参考咨询服务的质量控制综述 总被引:9,自引:1,他引:9
本文主要讨论网上协作式 (又称合作式 )数字参考咨询服务中的质量控制要素 ,及在其服务各环节各阶段实施质量控制的基本理念、方法、措施。 相似文献
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998.
Ronald E. Rice 《The Information Society》2005,21(4):285-299
This study summarizes prior reviews of new media and Internet research, and the growth of the term Internet in academic publications and online newsgroups. It then uses semantic network analysis to summarize the interests and concepts of an interdisciplinary group of Internet researchers, as represented by session titles and paper titles and abstracts from the 2003 and 2004 Association of Internet Researchers conferences. In both years, the most frequent words appearing in the paper abstracts included Internet, online, community, social, technology, and research. The 2003 papers emphasized topics such as the social analysis/research of online/Internet communication, community, and information, with particular coverage of access, individuals, groups, digital media, culture; role and process in e-organizations; and world development. The 2004 papers emphasized topics such as access; news and social issues; the role of individuals in communities; user-based studies; usage data; and blogs, women, and search policy, among others. 相似文献
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1000.
Knowledge sharing is a critical step for successful knowledge management. However, sharing knowledge not only requires time and effort of a knowledge worker but also reduces the unique value or power that the worker enjoys in the organization. Therefore, for successful knowledge sharing, a reward system is used to compensate knowledge sharing activities. In this paper, we consider a situation where there exists measurement inaccuracy in the actual amount of knowledge shared by risk-averse workers. We analyze the optimal reward system for knowledge sharing and the optimal investment to address measurement inaccuracy. Through the analysis, a simple optimal reward system is derived. This system is linear in the amount of knowledge sharing and compensates for the workers’ costs of knowledge sharing and risk-bearing. Additionally, the optimal investment to improve measurement accuracy is characterized by balancing the investment cost against the workers’ risk-bearing cost. Finally, a comparative statics analysis is conducted to investigate the effect of changes in exogenous factors on the optimal reward system, the amount of knowledge sharing, and the amount of optimal investment. Insights from our analysis can contribute to the better management of knowledge sharing through reward systems and the effective implementation of a knowledge management system. 相似文献