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Many enzymes and proteins have metal ions at their active sites that play key roles in catalysis. An important goal of an interdisciplinary field like bioinorganic chemistry is the development of small inorganic coordination complexes that not only reproduce structural and spectroscopic features, but also function in a manner similar to their natural counterparts. To highlight this burgeoning field, some selected results on synthetic modelling of (i) the electronic structure of manganese cluster of photosystem II and (ii) functional modelling of the dinuclear copper enzyme tyrosinase are described in this article.  相似文献   
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Instructional design (ID) professionals typically employ models that guide their practice. However, it is unclear how a specific model is selected for an instructional situation. Andrews and Goodson (1980) provided a valuable procedure for comparing instructional design models, but because of the proliferation of variations in instructional design applications during the past decade, the introduction of instructional design into new learning contexts and the emergence of alternative approaches to instructional design, there has emerged a need for a new framework which assesses the potential success of any instructional design model. A framework is presented here which is intended to provide a conceptual tool for determining appropriate instructional design applications.  相似文献   
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Social work students have few guidelines to help them evaluate the implication of their posted information on Internet-based social networking sites (SNSs). There is a national trend among employers of human services to cross-check publicly available online information on applicants. Based on data from a survey of 105 baccalaureate and master's social work students at a Midwestern university, this study explored students' perspectives on problematic information on SNSs. The majority reported that they had posted information on SNSs that they would not want their prospective employers to cross-check. Students offered a wide range of opinions, attitudes, and characteristics that contribute to the assessment of the risks that information they post on SNSs pose for their profession. The purpose of this study is to stimulate a conversation among social work educators on how to inculcate awareness and training of students on the ethical implications of SNS participation and to discuss directions for future research.  相似文献   
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Alcohol consumption and health outcomes are complex and multidimensional. Ethanol (1.6g / kg body weight/ day) exposure initially affects liver function followed by renal function of 16–18 week-old male albino rats of Wistar strain weighing 200–220 g. Chronic ethanol ingestion increased in thiobarbituric acid reactive substances level and glutathione s-transferase activity; while decreased reduced gluatathione content and activities of catalase, glutathione peroxidase and glutathione reductase in a time dependent manner in the hemolysate. Though superoxide dismutase activity increased initially might be due to adaptive response, but decreased later. Elevation of serum nitrite level and transforming growth factor-b1 activity indicated that long-term ethanol consumption may cause hepatic fibrosis and can elicit pro-angiogenic factors. However, no alteration in vascular endothelial growth factor-C activity indicated that ethanol consumption is not associated with lymphangiogenesis. Therefore, we conclude that long-term ethanol-induced toxicity is linked to an oxidative stress, which may aggravate to fibrosis and elevate pro-angiogenic factors, but not associated with lymphangiogenesis.  相似文献   
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Non-alcoholic fatty liver disease and its more aggressive form, non-alcoholic steatohepatitis are entities that are becoming more and more interesting to the medical community in general. A total of 93 Non-alcoholic fatty liver disease patients (64 male and 29 female) within the age range between 28 to 63 years were studied. All of them showed elevated alanine aminotransferase level (104.07 ± 56.04). Aspartate aminotransferase level (58.13 ± 31.96) was elevated more than its normal level in 82% cases and AST to ALT ratio was found 0.59 ± 0.26. Predisposing factors were diabetes mellitus (37%), obesity (13%) and hyperlipidemia (41%). In addition, 32% of the subjects were overweight.18% of the patients had elevated serum bilirubin. Our findings recommend a lower cutoff value than suggested by the World Health Organization for overweight and obesity among this racial-ethnic group.  相似文献   
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We describe a case of poorly differentiated adenocarcinoma of stomach, which did not present typical symptoms of gastrointestinal malignancy on first visit. The patient, a 62 year old smoker presented with shortness of breathe and pain in right lumbar region with no history of fever. Bone scans revealed multiple hot spots in skull, sternum, lumbar vertebrae and both iliac crests. A series of tumor markers were ordered which include PSA, CEA, CA19.9, CA 72.4 and AFP. Serum PSA and AFP concentrations were within normal range. Serum CEA and CA 72.4 were raised significantly. Markedly elevated levels of serum CA19.9 were found (>45000 U/ml) in this patient. CT chest and bronchoscopic examination ruled out the possibility of cancer lung. Upper GI tract endoscopy was done to find out lesion in GI tract. An ulcerative lesion was found in lesser curvature of stomach. Histopathological examination of endoscopic biopsy revealed a poorly differentiated adenocarcinoma of stomach. An unusually high serum CA19.9 (>45000U/ml) in case of gastric carcinoma has not been reported earlier.  相似文献   
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HER-2 is overexpressed in approximately 20–30% of invasive Breast Cancer. ECD of the HER-2 protein is frequently cleaved and released into the circulation, where it can be detected by ELISA in up to 45% of patients with metastatic breast cancer. The objective of our study was to compare the current methods for the detection of HER-2 protein. Tissue HER-2 levels were studied in 100 breast cancer patients by IHC and compared with serum HER-2 levels by ELISA. IHC frequency was 29%. Serum HER-2 ECD was positive in 42% of patients. A statistically significant correlation was observed. HER-2 detected by IHC correlates significantly with serum HER-2 levels detected by ELISA. Thus, ELISA is a reliable and economical tool to assess the HER-2 status in tumors, when breast tissue sample is not available.  相似文献   
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