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41.
Published reports of the effectiveness of preterm birth prevention programs have produced mixed results. Many larger observational studies suggest benefit. The randomized trials, however, suggest no effect on reducing rates of preterm birth in high-risk populations. This article reviews and critiques these reports and suggests areas for further research.  相似文献   
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A firefly luciferase bioluminescent assay of bacterial adenosine triphosphate (ATP) was used to measure the toxic effects of metal ions on six bacterial genera isolated from two geographically different marsh treatment systems. The toxicity of eleven different metals, as well as metal mixtures, was monitored using the agar plate test and the resazurin reduction test in addition to measurement of intracellular ATP. All the organisms surveyed tended to be sensitive to much lower concentrations of metals when the metals were present in mixtures. Isolates from a marsh system constructed on normal soil exhibited lower metal resistance patterns than organisms isolated from a marsh built on mine tailings. The intracellular ATP assay appeared to be the most sensitive method of determining the viability of bacterial cells following metal treatment.  相似文献   
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PURPOSE: To provide a primer for novice nurse scientists about the increasingly regulated human research environment. ORGANIZING CONSTRUCTS: Federal regulations and international guidelines about protection of human research participants are discussed, with particular attention to institutional review boards for human research. CONCLUSION: Understanding the processes used by institutional review boards to foster ethical human research promotes collaborative interactions and supports compliant research work.  相似文献   
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Dietary supplementation with vitamin K(1), with vitamin D(3) and calcium or their combination, was examined in healthy older women during a 2-year, double-blind, placebo-controlled trial. Combined vitamin K with vitamin D plus calcium was associated with a modest but significant increase in BMC at the ultradistal radius but not at other sites in the hip or radius. INTRODUCTION: The putative beneficial role of high dietary vitamin K(1) (phylloquinone) on BMD and the possibility of interactive benefits with vitamin D were studied in a 2-year double-blind, placebo-controlled trial in healthy Scottish women > or =60 years of age. MATERIALS AND METHODS: Healthy, nonosteoporotic women (n = 244) were randomized to receive either (1) placebo, (2) 200 microg/day vitamin K(1), (3) 10 microg (400 IU) vitamin D(3) plus 1000 mg calcium/day, or (4) combined vitamins K(1) and D(3) plus calcium. Baseline and 6-month measurements included DXA bone mineral scans of the hip and wrist, markers of bone turnover, and vitamin status. Supplementation effects were tested using multivariate general linear modeling, with full adjustment for baseline and potential confounding variables. RESULTS: Significant bone mineral loss was seen only at the mid-distal radius but with no significant difference between groups. However, women who took combined vitamin K and vitamin D plus calcium showed a significant and sustained increase in both BMD and BMC at the site of the ultradistal radius. Serum status indicators responded significantly to respective supplementation with vitamins K and D. Over 2 years, serum vitamin K(1) increased by 157% (p < 0.001), the percentage of undercarboxylated osteocalcin (%GluOC) decreased by 51% (p < 0.001), serum 25-hydroxyvitamin D [25(OH)D] increased by 17% (p < 0.001), and PTH decreased by 11% (p = 0.049). CONCLUSIONS: These results provide evidence of a modest synergy in healthy older women from nutritionally relevant intakes of vitamin K(1) together with supplements of calcium plus moderate vitamin D(3) to enhance BMC at the ultradistal radius, a site consisting of principally trabecular bone. The substantial increase in gamma-carboxylation of osteocalcin by vitamin K may have long-term benefits and is potentially achievable by increased dietary intakes of vitamin K rather than by supplementation.  相似文献   
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Fear of falling, defined as a lack of self-confidence that one may avoid falls while doing everyday activities, may have serious consequences for elderly people. This article examines the prevalence, risk factors, and consequences of fear of falling in the elderly population; methods for assessing those fears; and suggests evidence-based interventions. Incorporating successful strategies into programs to reduce falling can result in improved patient outcomes as well as decreased healthcare utilization and costs.  相似文献   
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