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Objective: To determine whether exposure to polychlorinated biphenyls (PCBs) or dichlorodiphenyl dichloroethene (DDE), either transplacentally or through breast feeding, affected scores on the Bayley Scales of Infant Development at 6 or 12 months of age. DESIGN: Cohort followed from birth to 1 year of age. SETTING: General community. PARTICIPANTS: Volunteer sample of 858 infants, of whom 802 had Bayley scores available at either 6 months or 12 months or both. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Bayley scales and chemical measurements were done independently. Higher transplacental exposure to PCBs was associated with lower psychomotor scores at both 6 and 12 months of age; the difference between the mean scores in the lowest and highest PCB groups was 7 points at 6 months and 8 points at 12 months. Higher transplacental exposure to DDE was associated with higher mental scores at 6 months of age (the difference between the mean scores in the lowest and highest DDE groups was 6 points), but no relationship was seen at 12 months. Exposure to either chemical through breast feeding was apparently unrelated to Bayley scores. Conclusions: Transplacental exposure to PCBs was associated with lower psychomotor scores. No deleterious effects were associated with breast feeding.  相似文献   
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OBJECTIVE: To estimate how well a convenience sample of women from the general population could self-screen for contraindications to combined oral contraceptives using a medical checklist. METHODS: Women 18-49 years old (N=1,271) were recruited at two shopping malls and a flea market in El Paso, Texas, and asked first whether they thought birth control pills were medically safe for them. They then used a checklist to determine the presence of level 3 or 4 contraindications to combined oral contraceptives according to the World Health Organization Medical Eligibility Criteria. The women then were interviewed by a blinded nurse practitioner, who also measured blood pressure. RESULTS: The sensitivity of the unaided self-screen to detect true contraindications was 56.2% (95% confidence interval [CI] 51.7-60.6%), and specificity was 57.6% (95% CI 54.0-61.1%). The sensitivity of the checklist to detect true contraindications was 83.2% (95% CI 79.5-86.3%), and specificity was 88.8% (95% CI 86.3-90.9%). Using the checklist, 6.6% (95% CI 5.2-8.0%) of women incorrectly thought they were eligible for use when, in fact, they were contraindicated, largely because of unrecognized hypertension. Seven percent (95% CI 5.4-8.2%) of women incorrectly thought they were contraindicated when they truly were not, primarily because of misclassification of migraine headaches. In regression analysis, younger women, more educated women, and Spanish speakers were significantly more likely to correctly self-screen (P<.05). CONCLUSION: Self-screening for contraindications to oral contraceptives using a medical checklist is relatively accurate. Unaided screening is inaccurate and reflects common misperceptions about the safety of oral contraceptives. Over-the-counter provision of this method likely would be safe, especially for younger women and if independent blood pressure screening were encouraged.  相似文献   
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Collagen peptide mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, also known as zooarchaeology by mass spectrometry (ZooMS), is a rapidly growing analytical technique in the fields of archaeology, ecology, and cultural heritage. Minimally destructive and cost effective, ZooMS enables rapid taxonomic identification of large bone assemblages, cultural heritage objects, and other organic materials of animal origin. As its importance grows as both a research and a conservation tool, it is critical to ensure that its expanding body of users understands its fundamental principles, strengths, and limitations. Here, we outline the basic functionality of ZooMS and provide guidance on interpreting collagen spectra from archaeological bones. We further examine the growing potential of applying ZooMS to nonmammalian assemblages, discuss available options for minimally and nondestructive analyses, and explore the potential for peptide mass fingerprinting to be expanded to noncollagenous proteins. We describe the current limitations of the method regarding accessibility, and we propose solutions for the future. Finally, we review the explosive growth of ZooMS over the past decade and highlight the remarkably diverse applications for which the technique is suited.  相似文献   
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Objective. To assess the effectiveness of virtual patient cases to promote self-directed learning (SDL) in a required advanced therapeutics course.Design. Virtual patient software based on a branched-narrative decision-making model was used to create complex patient case simulations to replace lecture-based instruction. Within each simulation, students used SDL principles to learn course objectives, apply their knowledge through clinical recommendations, and assess their progress through patient outcomes and faculty feedback linked to their individual decisions. Group discussions followed each virtual patient case to provide further interpretation, clarification, and clinical perspective.Assessments. Students found the simulated patient cases to be organized (90%), enjoyable (82%), intellectually challenging (97%), and valuable to their understanding of course content (91%). Students further indicated that completion of the virtual patient cases prior to class permitted better use of class time (78%) and promoted SDL (84%). When assessment questions regarding material on postoperative nausea and vomiting were compared, no difference in scores were found between the students who attended the lecture on the material in 2011 (control group) and those who completed the virtual patient case on the material in 2012 (intervention group).Conclusion. Completion of virtual patient cases, designed to replace lectures and promote SDL, was overwhelmingly supported by students and proved to be as effective as traditional teaching methods.  相似文献   
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Hearing Aids     
The authors outline their present policy with regard to indications for surgery in. cases of mitral stenosis. They believe their scientific objectives will encourage constant revision of these indications in the future in case new procedures and more conclusive long-term observations require the modification of these indications. Time and continuous research will be the determining factors in this matter.  相似文献   
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