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991.
The oxidative modification of lipoprotein especially low density lipoprotein (LDL) plays a key role in the initiation and progression of atherosclerosis. Serum apolipoproteinB (apoB) level is found to be an important marker for atherosclerosis. The present paper focuses on the measurement of serum apoB levels and the effect of Vitamin E, Vitamin C and reduced glutathione on the copper ion induced oxidation of LDL + VLDL (VLDL-Very Low Density Lipoprotein) lipoprotein fraction isolated from the serum of chronic renal failure (CRF) and renal transplanted patients. The level of apoB is significantly higher in the serum of transplanted patients when compared to CRF patients and normal subjects. The level of TBARS formed in oxidized LDL + VLDL lipoprotein fraction of CRF and renal transplanted patients are significantly increased than normal even in the presence of antioxidants but the level of TBARS produced, with antioxidants is comparatively lesser than that produced by oxidized lipoprotein fraction without antioxidants. It may be concluded than that produced by oxidized lipoprotein fraction without antioxidants. It may be concluded that oxidation of LDL can be prevented at an earlier stage by Vitamin E supplementation. The supplementation with Glutathione serves as the best method of preventing the lipoprotein oxidation among the renal diseased patients.  相似文献   
992.
993.
Benson KR 《Endeavour》2000,24(2):59-62
The modern discipline of biology was formed in the 20th century from roots deep in the natural-history tradition, which dates from Aristotle. Not surprisingly, therefore, ecology can also be traced to natural history, especially its 19th-century tradition emphasizing the adaptive nature of organisms to their environment. During the 20th century, ecology has developed and matured from pioneering work on successional stages to mathematically rich work on ecosystem energetics. By the end of the century, ecology has made a return to its natural-history heritage, emphasizing the importance of the integrity of ecosystems in considering human interactions with the environment.  相似文献   
994.
Indian ethnicity by itself is a strong risk factor for development of CAD in Indian postmenopausal women due to lower HDL levels as compared to Whites and women of oriental origin. We evaluated and compared the short-term effects of menopause, estrogen replacement therapy and combined estrogen and progestin replacement therapy on various atherogenic indices. 40 postmenopausal women, both surgical and natural (20 each) were selected. 10 surgical postmenopausal women were given 0.625 mg conjugated estrogens daily for 6 months and 10 natural postmenopausal women were given 0.625 mg conjugated estrogen with 2.5 mg medroxyprogesterone acetate daily. 20 women were included in the control group and given placebo. Fasting venous blood samples were analyzed for extended lipid profile and calculated atherogenic indices before starting the therapy and after 1,3 and 6 months. LDL and Apolipoprotein B increased (p<0.05) and those of Apolipoprotein A1 and HDL decreased in the control groups. In both the study groups levels of serum cholesterol and LDL decreased (p<0.05) and those of HDL and Apolipoprotein A1 increased (p<0.01). LDL/HDL, Apo B/ApoA1, Total Cholesterol/HDL decreased significantly (p<0.05) in both the study groups compared to the control groups. The effect of estrogen alone was more significant as compared to combination therapy. Log Triglycerides (TG)/HDL ratio showed a decrease in women on estrogen alone but the difference was not significant. Our study confirms that short term HRT has a favorable effect on atherogenic indices in Indian postmenopausal women.  相似文献   
995.
During the period 1952 to 1965, there were strenuous world-wide efforts to produce an automated cotton spinning mill. These attempts, which involved the use of concepts developed outside the textile machinery industry (i.e. automatic transfer systems), were motivated by the need to reduce the very great amount of manual handling of packages between successive operations in the yarn manufacturing process.The case is unusual in that, while many of the developments were ‘technically successful’ in that installations were made which functioned satisfactorily in the mill), they were, without exception, commercially unsuccessful from the point of view of the machinery manufacturer and mill operator. This paper describes the economic forces which led to the attempts at automation, and explains why, after an expenditure in excess of £ 25 mill/on worldwide, commercial success was not achieved.The prime reason for failure lay in minor and major developments of existing individual machines, which had continued independently of automation research, and which had, to a great extent, obviated the economic need for automation. The surprising thing (in retrospect at least), is that, as production rates were increased step by step, development engineers working to produce automated systems saw, in the increasing speeds, only a challenge to their ingenuity — not a disappearance of the need for automatic transfer devices.A secondary reason for failure in the particular case of the Shirley Institute's automated card room sequence lay in the fact that the research was directed by a committee whose terms of reference were limited to pursuance of a defined goal — the development of an automated card room. The committee had no mandate to question the soundness of its objectives, and the work continued until a technically successful system was finally produced.  相似文献   
996.
Firms vary greatly in their rates of creating and adopting technological and organizational innovations, in part because of their choice of reference group. We argue that the selection of a reference group is a crucial and neglected source of firm heterogeneity. Comparisons to the average of other firms in a population cause most firms to adopt innovations once they are widely accepted. A distinctive feature of the minority of innovating firms that create innovations or adopt them early is that they compare themselves with, compete with, and try to differ from other innovating firms, whereas the majority of firms compare themselves with, and conform to, a broader group of firms. We elaborate this argument based on the behavioral theory of the firm and institutional theory, and test it on a two-period survey on adoptions of innovative organizational forms in Europe and the US. The analysis shows the predicted differences in the adoption patterns of innovating and imitating firms.  相似文献   
997.
Early identification of patients with acute myocardial infarction is of prime importance due to the associated very high mortality. Only 22% of the patients presenting at emergency cardiology care with chest pain have coronary disease. A number of biochemical tests like CKMB and Troponin-T/I have been introduced for early detection of the coronary syndrome (ACS). Ischemia modified albumin (IMA) has been recently introduced as a marker of myocardial ischemia. We estimated serum IMA in four sequential samples from 25 patients admitted to ICCU. Twenty five healthy volunteers formed the control group from which the normal range was derived. IMA was significantly raised in ischemia patients than in controls as well as compared to the patients who did not have cardiac ischemia. IMA demonstrated good discrimination between the ischemic and the non-ischemic patients with an Odds Ratio of 16.9 (6.29–46.87) than CKMB which showed an Odds Ratio of 2.07 (1.18–6.08). Sensitivity and specificity of IMA for the detection of ACS was 78.0% and 82.7% compared to 58.0% and 60.0%, respectively for the CK-MB assay. The area under the ROC curve of IMA for ischemic v/s non-ischemic patients was 0.834. IMA appears to be developing into a new and very potent marker, of cardiac ischemia.  相似文献   
998.
999.
1000.
Research and development at the nanoscale requires a large degree of integration, from convergence of research disciplines in new fields of enquiry to new linkages between start-ups, regional actors and research facilities. Based on the analysis of two clusters in nanotechnologies (MESA+ (Twente) and other centres in The Netherlands and Minatec in Grenoble in France), the paper discusses the phenomenon of technological agglomeration: co-located scientific and technological fields associated to coordinated technology platforms to some extent actively shaped by institutional entrepreneurs. Such co-location and coordination are probably a pre-requisite for the emergence of strong nanoclusters.  相似文献   
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