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The versatility of isotope ratio mass spectrometry is demonstrated by reference to diverse case studies. Variations in the natural isotopic composition of non-biological, organic materials are compared as a means by which samples may be associated or discriminated. These techniques may be used to augment or compliment conventional forensic methodologies. delta13C analysis was used to demonstrate that different masking tape had been recovered in two, apparently similar cases, involving the smuggling of money. Visually similar ecstasy tablets were compared by consideration of the delta13C and delta15N composition of MDMA extracted from the tablets. Although only a limited number of tablets were analysed, the isotopic similarity between two different seizures was sufficient to induce a guilty plea from a person suspected of possessing both. A combination of delta2H, delta13C, delta15N and delta18O together with GC-MS analyses were applied to small samples of seized heroin. Although GC-MS analysis indicated differences between the chemical composition of two of the heroin samples, isotopic analysis suggested similarities, which were confirmed by further delta2H, delta13C and delta18O isotopic analysis of the clingfilm in which the samples were wrapped.  相似文献   
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This study evaluates the emerging field of medical outcomes research based on interviews at Harvard Medical School. Medical outcomes research at Harvard is multifaceted, but may be summarized as involving certain key components. The emphasis at Harvard is on “quality of care,” viewed as a combination of outcomes evaluation and process evaluation, delivery of the service and its result. In a time of shrinking budgets, outcomes and process research can be justified economically because of the relatively low cost of patient self‐reports and because of their usefulness. Physicians may be motivated to measure quality of care by emphasizing the positive effects of research on the process of care and outcomes. Medical outcomes research is a field that is undergoing change and is becoming increasingly oriented toward the practical needs of patients and physicians.  相似文献   
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The conclusion of the Clinton Administration presents an opportune time to investigate the outcomes of the National Performance Review (NPR). Any such evaluation, however, is complicated by the nature of the objectives sought, many of which relate to subtle and elusive elements of organizational life: empowering employees, inducing a less risk-adverse culture, and enhancing the quality of service delivery. The strategy employed here as a means of gaining insight into such phenomena was to couple a broad review of government-wide survey results with an in-depth investigation into the impact of NPR on a single agency, the Social Security Administration. A conclusion is that many of the NPR's "higher-order" objectives have not been met on a systemic basis. While a variety of proximate explanations for this finding can be identified, a more fundamental explanation relates to a failure by the sponsors to adjust their strategy to account for basic differences between NPR and past reforms.  相似文献   
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