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This ecologic study aimed to investigate whether differences in population mortality from lung, stomach and colorectal cancer among the 16 cohorts of the Seven Countries Study could be explained by differences in the average intake of anti-oxidant (pro)vitamins. In the 1960s, detailed dietary information was collected in small sub-samples of the cohorts by the dietary record method. In 1987, food-equivalent composites representing the average food intake of each cohort at baseline were collected locally and analyzed in a central laboratory. The vital status of all participants was verified after 25 years of follow-up. The average intake of vitamin C was strongly inversely related to the 25-year stomach-cancer mortality (r = -0.66, p = 0.01), also after adjustment for smoking and intake of salt or nitrate. The average intake of alpha-carotene, beta-carotene, and alpha-tocopherol were not independently related to mortality from lung, stomach or colorectal cancer, nor was vitamin C related to lung and colorectal cancer.  相似文献   
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OBJECTIVES: We sought to evaluate the effects of combined administration of infra-low dose dipyridamole and low dose dobutamine on assessment of myocardial viability. BACKGROUND: Low dose pharmacologic stress echocardiography with either dobutamine or dipyridamole infusion has been proposed for the recognition of myocardial viability. METHODS: Thirty-four patients with rest wall motion dyssynergy by two-dimensional echocardiography and with angiographically proved coronary artery disease underwent in combination with two-dimensional echocardiographic monitoring: 1) low dose (5 to 10 microgram/kg per min over 3 min) dobutamine infusion; 2) infra-low dose (0.28 mg/kg over 4 min) dipyridamole infusion; 3) combination of infra-low dose dipyridamole infusion immediately followed by low dose dobutamine infusion (combined dipyridamole-dobutamine). RESULTS: Follow-up rest echocardiography was available in 30 patients. After revascularization, 82 segments showed a contractile improvement of > or = 1 grade, whereas 63 segments remained unchanged. The sensitivity of dobutamine, dipyridamole and combined dipyridamole-dobutamine for predicting recovery was 72% (95% confidence interval [CI] 60.9% to 81.3%), 67% (CI 55.8% to 77%) and 94% (CI 86.3% to 97.9%), respectively. The specificity of dipyridamole, dobutamine and combined dipyridamole-dobutamine was 95% (CI 86.7% to 99%), 92% (CI 82.4% to 97.3%) and 89% (CI 78.4% to 95.4%), respectively. The accuracy of the dobutamine, dipyridamole and combined dipyridamole-dobutamine test was 80%, 79% and 92%, respectively (combined dipyridamole-dobutamine vs. dobutamine, p < 0.05; combined dipyridamole-dobutamine vs. dipyridamole, p < 0.01). CONCLUSIONS: Infra-low dose dipyridamole added to low dose dobutamine recruits an inotropic reserve in asynergic segments that were nonresponders after either dobutamine or dipyridamole alone and destined to recover after revascularization.  相似文献   
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New literature results on the liquid equilibria in the three edge binary systems make necessary a reconsideration and correction of liquidus surfaces of the γ and δ solid solutions hitherto outlined in the literature. Therefore, with respect to the critically reinterpreted edge binary systems, the shape of the stable liquidus surface of the γ and δ solid solutions has been newly outlined.  相似文献   
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BACKGROUND: Are trends in coronary heart disease deaths based on risk factor changes? OBJECTIVE: To study the relationship between trends in coronary deaths and changes in blood cholesterol in the Seven Countries Study. MATERIAL AND METHODS: Sixteen cohorts of men aged 40-59 years from seven countries (U.S.A., Finland, the Netherlands, Italy, Croatia (former Yugoslavia), Serbia (former Yugoslavia), Greece, Japan) were units for the analyses of serum cholesterol measured at entry and after 5 and 10 years, and for mortality over 25 years. RESULTS: In the populations, the ecological relationship of mean serum cholesterol at entry to late coronary heart disease death rates during the 10- to 25-year follow-up was weak, with an R-square of 0.31. Cholesterol measurements made at year 10, and an indicator of cholesterol change during the first 10 years, increased the association (R-square, 0.49). A negative and significant interaction was shown between baseline population cholesterol levels and their 10-year change. As an indicator of acceleration in mortality, cholesterol change over 10 years was also positively correlated (partial R-square 0.44) with the ratio of 25-year to 5-year deaths. CONCLUSIONS: In the Seven Countries Study, late coronary heart disease death rates are largely "explained' by changes in blood cholesterol levels during the early phases of the study, mainly due to increases in lower cholesterol levels among some cohorts.  相似文献   
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Basalt has remarkable physical and mechanical characteristics. However, its use and further processing is limited due to mechanical characteristics, e.g., density, hardness, fraying resistance, etc. The basalt–polymer composite enable maintains of physical and mechanical characteristics, further processing, and broader basalt application in various industries. Consequently, composites characterization, and production process technological parameters influence on the composites properties need to be appraised.  相似文献   
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This paper presents an improved method of current reference determination for a parallel active power filter. To insure sinusoidal line currents, thus reducing reactive power, an integrative method of reference calculation is applied. As a result, satisfactory response of line current to the load change is achieved. One of the major problems, the synchronization to the net voltage, is also considered. Classical solution is based on zero-cross detection of line voltage. Since this approach is very sensitive to the voltage distortions, a new method is suggested, relying on voltage fundamental harmonic calculation. These ideas were tested on a three-phase active power filter, controlled by 32-bit microcontroller  相似文献   
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STUDY DESIGN: A randomized, open, long-term, repeated-dose comparison of an anti-inflammatory drug and two opioid regimens in 36 patients with back pain. OBJECTIVES: To examine the long-term safety and efficacy of chronic opioid therapy in a randomized trial of patients with back pain. METHODS: All participants underwent a 4-week washout period of no opioid medication before being randomly assigned to one of three treatment regimens for 16 weeks: 1) naproxen only, 2) set-dose oxycodone, or 3) titrated-dose oxycodone and sustained-release morphine sulfate. All patients then were assigned to a titrated dose of opioids for 16 weeks and then gradually tapered off their medication for 12 weeks. Finally, all participants were monitored for a 1-month posttreatment washout period. Each patient was called once a week for a report on pain, activity, mood, medication, hours awake, and adverse effects and was monitored carefully for signs of abuse and noncompliance. RESULTS: Weekly reports during the experimental phase showed the titrated-dose group to have less pain (P < 0.001) and less emotional distress (P < 0.001) than the other two groups. Both opioid groups were significantly different from the naproxen-only group. During the titration phase, patients also reported significantly less pain and improved mood. Few differences were found in activity or hours asleep, or between average pretreatment and posttreatment phone-interview and questionnaire variables. No adverse events occurred, and only one participant showed signs of abuse behavior. CONCLUSIONS: The results suggest that opioid therapy has a positive effect on pain and mood but little effect on activity and sleep. Opioid therapy for chronic back pain was used without significant risk of abuse. However, tapered-off opioid treatment is palliative and without long-term benefit.  相似文献   
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Interpretation of geophysical data is greatly aided by the combined analysis of data from diverse sources. Probability theory provides a general framework for integrating geophysical data sets. We discuss the application of joint and conditional probability density functions (PDF) to the detection of anomalies and the prediction and interpolation of geo-variables. Density estimation techniques are discussed and illustrated on a geophysical data set from West Africa consisting of magnetic, elevation, and radiometric data.  相似文献   
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