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441.
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This article concerns new developments in autologous adult stem cell research in Japan and India through the notions of biohierarchy and bionetworking. It conceptualizes how human subject research in one country may be turned into experimental stem cell therapies in another through bionetworks. We analyse the processes that enable researchers in Japan to discard a therapy as being of reputational risk, while researchers in India employ it so that it becomes reputation enhancing. At the same time, scientists from both countries collaborate in and potentially benefit from the same bionetwork. Explaining how the recruitment of patients and scientists is organized through bionetworking, this article analyses how experimental research in India thrives using Japanese technologies. The concept of biohierarchy illustrates how inequalities in health and standards of living in India and in Japan underpin the methods by which researchers, medical professionals, managers and patients collaborate in bionetworks. The concept of 'boundary object' here captures the ways in which the meaning of experimental therapy is defined by subjective categories projected onto it by patients and scientists alike. The article is based on fieldwork conducted by both authors during 3 months between September and December 2008 at various locations in India and Japan. Data for this article were collected from a wide range of interviews with stem cell researchers, medical doctors, coordinators, managers and patients, primary and secondary sources gathered at these centres, and through web and archival research.  相似文献   
443.
We have studied the expression of lactate dehydrogenase and its isoforms in gall bladder cancer, cholelithiasis and chronic cholecystitis. Quantitative and qualitative assays of lactate dehydrogenase and its various isoforms were carried out in the blood sera of patients and healthy controls along with parallel estimation of various liver function test enzymes. Statistical analysis was done using the software Graph Pad Prism. Significantly high expression of lactate dehydrogenase along with alkaline phosphatase and total bilirubin (P ≤ 0.05) was observed in all the three clinical conditions as compared to controls. LDH showed an increasing trend from stage I to stage IV of GBC indicating a significant positive association with the disease progression. The levels of LDH 3 and 4 isoforms appeared significantly more elevated in GBC than cholelithiasis or chronic cholecystitis. We suggest that a careful estimation of total LDH and its isoforms 3 and 4 alone or along with alkaline phosphatase and total bilirubin during different clinical stages, like chronic cholecystitis, cholelithiasis and GBC, may prove to be a potentially useful biomarker in the prognostic management of gall bladder diseases, specifically GBC.  相似文献   
444.
Even as the theory of relativity is more than a hundred years old, it is not within easy reach of undergraduate students. These students have an insatiable urge to learn more about it even if the full machinery of the tools required to study the same is not within their comfortable reach. The recent detection of gravitational waves has only augmented their enthusiasm about the General Theory of Relativity (GTR), developed just over a hundred years now, encapsulated in Einstein’s Field Equations. The GTR provided a consistent formulation of the theory of gravity, removed the anomalies in the Newtonian model, and predicted spectacular natural phenomena which eventual experiments have testified to. This pedagogical article retraces some of the major milestones that led to the GTR and presents a simple numerical simulation of the GTR advance of the perihelion of planetary motion about the sun.  相似文献   
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Solving real-world problems is an effective learning activity that promotes meaningful learning in formal educational settings. Problems can be classified as being either well structured or ill structured. Internet information search approaches have an influential role to play in the successful performance of problem solving. A better understanding of how students differentially model information search strategies and movements in tackling well- and ill-structured problems is essential for creating engaging problem-solving environments for students. Static measures, such as the number of accessed nodes or links, or the number of times particular web browser function buttons are clicked, are limited in their ability to analyze attributes of information search patterns. A more dynamic and spatial representation of web movements and navigational patterns can be realized through the use of navigational paths as data. The two path-specific structural metrics that can be used to assess network-based navigational paths in relation to the structuredness of the problem-solving task are compactness and stratum. These metrics are, respectively, the indicators of the connectedness and linearity of network-based structures defining students’ online navigational visitations during the problem-solving sessions. This study explored the relevance and utility of these two metrics in analyzing the navigational movements of learners in seeking out electronic information to accomplish successful problem solving. The outcome findings of this study show that well- and ill-structured problems demand different cognitive and information seeking navigational approaches. The differing values of the two path metrics in analyzing the search movements organized by students in attending to well- and ill-structured problems were a direct result of the contrasting patterns of navigational path movements. The search patterns associated with well-structured problem solving tended to be more linear and less connected, whereas those related to ill-structured problem solving were more distributed and inter-connected.  相似文献   
447.
The 2010 Nobel Prize in Chemistry was awarded to three scientists, R F Heck, E-I Negishi and A Suzuki, for their work on “Palladium — Catalyzed Cross Couplings in Organic Synthesis”. It pertains to research done over a period of four decades. The synthetic procedures embodied in their work enable construction of C-C bond selectively between complex molecules as in simple ones at desired positions without disturbing any functional groups at other parts of the reacting molecules. The work finds wide applications in the synthesis of pharmaceuticals, agricultural chemicals, and molecules for electronics and other applications. It would not have been possible to synthesize some of the complex natural products or synthetic compounds without using these coupling reactions in one ormore steps.  相似文献   
448.
Grapes are the richest source of antioxidants due to the presence of potent bioactive phytochemicals. In this study, the phytochemical contents, scavenging activities and protective role against H2O2-induced oxidative stress in liver tissue ex vivo of four grape (Vitis vinifera) cultivars extracts, namely Flame seedless (black), Kishmish chorni (black with reddish brown), Red globe (red) and Thompson seedless mutant (green), were evaluated. The total phenolics and flavonoids content in pulp or skin fractions of different grape cultivars were in the range of 47.6–310 mg gallic acid equivalent/g fresh weight (fw), and 46.6–733.3 µg catechin equivalent/g fw respectively. The scavenging activities in skin of different grape varieties against 2,2-diphenyl-1-picrylhydrazyl (44–58 %), hydrogen peroxide (15.3–18.6 %), and hydroxyl radicals (50–85 %), were higher than pulp of the corresponding cultivars. These scavenging activities of grape extracts were found to be significantly (p < 0.01) correlated with the levels of total phenols, flavonoids and ascorbic acid. Liver tissues from goat treated with H2O2 (500 μM) showed significantly decreased GSH content by 42.9 % and activities of catalase by 50 % and glutathione reductase by 66.6 %; while increased thiobarbituric acid reactive substances and nitric oxide level by 2.53- and 0.86-fold, respectively, and activity of glutathione S-transferase by 0.96-fold. Grape skin extracts showed the stronger protective activity against H2O2-induced oxidative stress in liver tissue ex vivo, than its pulp of any cultivar; and the Flame seedless (black) cultivar showed the highest potential. In conclusion, our study suggested that the higher antioxidant potential, phytochemical contents and significant scavenging capacities in pulp and skin of grape extracts showed the protective action of grape extracts against H2O2-induced oxidative stress in liver tissue ex vivo.  相似文献   
449.
Coronary artery disease (CAD) is a global epidemic currently. This study was planned to evaluate markers of inflammation and hemostasis and their possible association, if any, in patients with CAD. The study was carried out in 60 patients with acute myocardial infarction (AMI) and 60 age and gender matched controls. The following parameters were assayed in all study subjects-inflammatory-interleukin (IL)-10, high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-α, fibrinogen; hemostatic-fibrinogen, fibrin D-dimer and a novel risk factor—homocysteine. Inflammatory markers (hs-CRP, TNF-α and IL-10), fibrinogen, fibrin D-dimer and homocysteine levels were significantly higher in the patients with AMI, as compared with controls. A positive correlation was observed between D-dimer and the inflammatory markers—hs-CRP and TNF-α. Upon multivariate analysis, TNF-α emerged as the best determinant of CAD in our study. Our results indicate that there is a possible interplay of inflammation and hemostasis in CAD, underlining their synergistic role in the pathogenesis of CAD.  相似文献   
450.
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