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Concentrations of trace metals judged potentially carcinogenic were determined in samples of amosite, crocidolite, and chrysotiie. The samples included commercial material as shipped, milled and processed material as collected in animal exposure chambers, and International Union Against Cancer (UICC) reference samples. The metals determined were cobalt, nickel, chromium, manganese, and iron. The samples were treated with hydrofluoric acid, the residue taken up with hydrochloric acid, and the determination made by atomic absorption spectrometry. Substantial enrichment of the dusts in nickel and chromium during milling and dissemination was found. Cobalt and nickel content was different from that in UICC samples.  相似文献   
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Purpose : This paper describes the types of difficulties older people have with their home environments and the factors associated with having such difficulties. Method : Data were used from 296 study participants of the University at Buffalo's Consumer Assessments Study that examines the home modification needs and environmental difficulties of older people. A combination of socio-demographic variables, health and functional status indicators and measures of psychosocial well-being were used to predict environmental problems. Results : An average of 13 problems with the environment that posed as a barrier to safe and independent performance was observed in homes. It was found that most difficulties occurred in bathrooms, kitchens, bedrooms and access to entryways and rooms. Hierarchical multiple regression analysis showed that having home environmental problems was most strongly associated with younger age, being female, being of minority status, having pain, and greater physical disability. Conclusion : The findings show that a combination of conditions that include demographic and functional conditions place older people at risk for problems with the home environment that impede performance of daily living activities.  相似文献   
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Background: Recent research documents widespread deficits in the physical examination skills of practicing physicians. Purpose: This study explored physical examination skills of 3rd-year medical students after completion of a course in physical diagnosis. Methods: Standardized patient physical examination checklist data were analyzed for a cohort of 2,038 medical students for a patient presenting with classic signs and symptoms of an acute myocardial infarction. A follow-up paper case and survey explored reasons underlying omissions. Results: Students systematically omitted 3 of 10 component maneuvers critical to the evaluation of a patient with shortness of breath and chest pain. The same pattern of omissions was observed across 8 medical schools and over 2 successive years. The paper case follow-up study ruled out time constraints and performance anxiety as the cause. Survey data revealed that students may omit a maneuver due to inability to recall pertinence (blood pressure in both arms) or difficulty discriminating findings (heart sounds at different locations), or because of inadequate technical mastery (percussion of the lungs). Conclusions: These data suggest fundamental inadequacies in the current paradigm for teaching physical examination skills. Standardized patient checklist data can provide an informative window into the efficacy of teaching practices.  相似文献   
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The Sm and RNP autoantibodies, found in the sera of many patients who have connective tissue diseases, recognize determinants on small nuclear ribonucleoprotein particles (snRNP). Numerous techniques have been used to distinguish between the subsets of snRNP proteins recognized by these two antibody systems. Using protein and snRNP immunoprecipitation, as well as a competitive enzyme-linked immunosorbent assay, antibodies in the sera of Sm patients have been observed to include variable quantities of RNP-like reactivity. To analyze changes in these autoantibodies, 2 patients with anti-Sm antibodies were followed temporally. The autoantibodies in the sera of both patients underwent shifts from predominant Sm reactivity to predominant RNP reactivity. In 1 patient the shift occurred gradually over several years, while in the other the shift occurred within 8 weeks.  相似文献   
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