首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   122篇
  免费   7篇
儿科学   1篇
基础医学   6篇
临床医学   9篇
内科学   60篇
神经病学   8篇
特种医学   2篇
外科学   5篇
综合类   2篇
预防医学   30篇
眼科学   1篇
药学   3篇
肿瘤学   2篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2019年   1篇
  2018年   3篇
  2016年   1篇
  2014年   2篇
  2013年   1篇
  2012年   5篇
  2011年   4篇
  2010年   3篇
  2009年   7篇
  2008年   8篇
  2007年   11篇
  2006年   5篇
  2005年   9篇
  2004年   8篇
  2003年   6篇
  2002年   5篇
  2001年   2篇
  2000年   6篇
  1999年   2篇
  1998年   5篇
  1997年   2篇
  1994年   1篇
  1992年   1篇
  1991年   3篇
  1990年   8篇
  1989年   6篇
  1988年   2篇
  1987年   1篇
  1984年   1篇
  1982年   1篇
  1979年   2篇
  1974年   1篇
  1970年   1篇
  1932年   1篇
排序方式: 共有129条查询结果,搜索用时 15 毫秒
121.
Data on the body mass index (BMI) from four Scandinavian countries are compared. The Finnish values are markedly higher than those of the other countries. This holds for both sexes. Among these the Norwegians deviate by showing higher values for females, though not reaching the Finnish level, but lower values for the males. The populations from which the observations are drawn are differently sampled. There is no evidence that differences as to composition in rural/urban populations can explain the differences.  相似文献   
122.
A common mutation (G-455--> A) in the promoter region of the beta-fibrinogen gene has been associated with elevated plasma fibrinogen levels. Whether fibrinogen genotype affects plasma fibrinogen levels and risk of ischemic heart disease in the general population has not been studied. We investigated the association between fibrinogen genotype, plasma fibrinogen levels, and ischemic heart disease in a general population sample (n = 9,127). The A-allele (relative frequency, 0.20) was associated with elevated plasma fibrinogen levels in both genders (P < 0.001). While the effect of the A-allele on fibrinogen level was additive in men, the effect was dominant in postmenopausal women. The A-allele raising effect appeared to be two- to threefold greater in individuals with ischemic heart disease than in those without. An increase of 1 SD in plasma fibrinogen increased the odds ratio for ischemic heart disease by approximately 20% (P < 0.01 for women and < 0.005 for men). However, the frequency of the A-allele was similar in those with and without ischemic heart disease, and genotype was not a predictor of disease. These results demonstrate that the (G-455--> A) mutation in the promoter region of the beta-fibrinogen gene is associated with an increase in plasma fibrinogen in both genders in the general population. This increase does not appear to cause ischemic heart disease.  相似文献   
123.
The aim of the study was to establish the effects of a range of psychosocial factors on weight changes and risk of obesity. The study population consisted of the 4,753 participants in the third (1991–1994) and fourth wave (2001–2003) of the Copenhagen City Heart Study, Denmark. At baseline the participants were asked comprehensive questions on major life events, work stress, vital exhaustion, social network, economic hardship, and intake of sleep medication. Weight and height were measured by health professionals. Weight changes and incident obesity was used as outcome measures. The participants on average gained 2 kg of weight and 8% became obese during follow-up. The experience of major life events in childhood, work life and adult life was associated with weight gain and obesity in women, but not in men. Vital exhaustion was associated with weight gain in a dose–response manner in men (P = 0.002) and younger women (P = 0.02). Persons with high vital exhaustion gained approximately 2 kg more during follow-up compared to those with no vital exhaustion. Women with high vital exhaustion were also more likely to become obese during follow-up (OR = 2.39; 95% CI: 1.14–5.03). There were no clear patterns in the associations between social network, economic hardship and weight gain or obesity. The number of psychosocial risk factors, as an indicator for clustering, was not associated with weight gain or obesity. In conclusion, major life events and vital exhaustion seem to play a role for weight gain and risk of obesity, especially in women.  相似文献   
124.
OBJECTIVE. The mechanisms by which overweight and physical inactivity lead to hypertension are complex. Leptin, an adipocyte-derived hormone, has been linked with hypertension. We wanted to investigate the relationship between leptin, physical activity and new-onset hypertension. METHODS. The study was a prospective cohort study of 744 women and 367 men, who were normotensive in the third Copenhagen City Heart Study (CCHS) examination, performed 1991?94. Based on questionnaire items, the participants were divided into two groups with low (n = 674) and high (n = 437) levels of leisure-time physical activity, respectively. RESULTS. Between the third and the fourth CCHS examination, performed 2001?03, 304 had developed hypertension, defined as systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg or use of antihypertensive medication. In a logistic regression model, including age, sex, body mass index, SBP, DBP, level of physical activity and leptin, we found a significant interaction between leptin and level of physical activity with new-onset hypertension as outcome variable (p = 0.012). When we entered the interaction variables, effect of leptin with low level of physical activity and with high level of physical activity, respectively, in the original model, leptin predicted new-onset hypertension in participants with low level of physical activity [odds ratio (95% confidence interval): 1.16 (1.01?1.33) for one unit increase in log-transformed leptin levels, p = 0.038], but not in participants with high level of physical activity [0.88 (0.74?1.05), p = 0.15]. CONCLUSION. We found that leptin predicted new-onset hypertension but only in participants with low level of physical activity.  相似文献   
125.
OBJECTIVES: This study was designed to determine whether measurement of plasma pro-B-type natriuretic peptide (proBNP) could be used in discriminating between cardiac and pulmonary dyspnea in the general population. BACKGROUND: Natriuretic peptides are useful markers in ruling out acute cardiac dyspnea in the emergency department, but their diagnostic significance in evaluating chronic dyspnea in the general population is unknown. METHODS: Within the Copenhagen City Heart Study, a large, community-based population study, dyspnea was evaluated by spirometry, oxygen saturation, echocardiography, and plasma proBNP. RESULTS: Of 2,929 participants, 959 reported dyspnea. The plasma proBNP concentration was higher in the group with dyspnea (mean 17.8 pmol/l; 95% confidence interval [CI] 16.3 to 19.4 pmol/l) than in the group without (10.6 pmol/l; 95% CI 10.0 to 11.4 pmol/l; p < 0.001). In the group with dyspnea, left ventricular hypertrophy and/or systolic dysfunction was associated with a 2.6-fold increase in plasma proBNP concentration (p < 0.001), whereas pulmonary dysfunction was not associated with increased plasma proBNP (p = 0.66). Using multivariable regression analysis, a model to estimate the expected concentration of plasma proBNP based on age and gender was established for dyspneic subjects: an actual plasma proBNP concentration below half of the expected value ruled out left ventricular systolic and diastolic dysfunction (sensitivity 100%, 95% CI 100% to 100%; specificity 15%, 95% CI 12% to 17%). CONCLUSIONS: In the general population with dyspnea, plasma proBNP concentrations are increased in left ventricular dilatation, hypertrophy, systolic dysfunction, or diastolic dysfunction, but are unaffected by pulmonary dysfunction.  相似文献   
126.

Background

Potassium supplementation reduces the risk of cardiovascular mortality and stroke in population studies; however, the prognostic impact of mild hypokalemia in the general population has not been thoroughly investigated. We aimed to investigate associations between mild hypokalemia and endpoints in the general population.

Methods

Participants (aged 48-76 years) from the general population study “Copenhagen City Heart Study” (n = 5916) were studied. Participants were divided into groups according to baseline values of plasma potassium (potassium): hypokalemia (<3.7 mmol/L, n = 758), normokalemia (3.7-4.5 mmol/L, n = 4973), and high potassium (>4.5 mmol/L, n = 185). Hypokalemia was further divided as potassium <3.4 mmol/L and 3.4-3.6 mmol/L. The primary endpoints were all-cause mortality and nonfatal validated ischemic stroke. The secondary endpoint was acute myocardial infarction (AMI). We adjusted for conventional risk factors, diuretics, and atrial fibrillation at baseline.

Results

Mean potassium in the hypokalemic group was 3.5 mmol/L (range, 2.6-3.6 mmol/L) and was associated (P < 0.05) with increased systolic blood pressure, higher CHA2DS2-VASc score, and increased use of diuretics as compared with normokalemia. Baseline atrial fibrillation was equally frequent across groups. Median follow-up-time was 11.9 years (Q1-Q3: 11.4-12.5 years). Hypokalemia was borderline associated with increased stroke risk in a multivariable Cox model (including adjustment for competing risk) as compared with normokalemia (hazard ratio [HR] 1.40; 95% confidence interval [CI], 1.00-1.98). The subgroup with potassium <3.4 mmol/L had higher stroke risk (HR 2.10; 95% CI, 1.19-3.73) and mortality risk (HR 1.32; 95% CI, 1.01-1.74) as compared with normokalemia. Hypokalemia was not associated with AMI, and no increased risk of mortality was seen with concomitant AMI and hypokalemia. No associations were seen with high potassium.

Conclusion

In a general population mild hypokalemia is associated with increased stroke risk and, to a lesser degree, increased mortality risk.  相似文献   
127.
128.
BACKGROUND: Although the J-shaped relation between alcohol intake and mortality has been reproduced in many large cohort studies, the question of whether the effects of beer, wine, and spirits differ remains controversial. OBJECTIVE: To examine the relation between intake of different types of alcohol and death from all causes, coronary heart disease, and cancer. DESIGN: Pooled cohort studies in which intake of beer, wine, and spirits; smoking status; educational level; physical activity; and body mass index were assessed at baseline. SETTING: Copenhagen, Denmark. PARTICIPANTS: 13 064 men and 11 459 women 20 to 98 years of age. MEASUREMENTS: Number of deaths and time to death from all causes, coronary heart disease, and cancer during follow-up. RESULTS: During 257 859 person-years of follow-up, 4833 participants died. J-shaped relations were found between total alcohol intake and mortality at various levels of wine intake. Compared with nondrinkers, light drinkers who avoided wine had a relative risk for death from all causes of 0.90 (95% CI, 0.82 to 0.99) and those who drank wine had a relative risk of 0.66 (CI, 0. 55 to 0.77). Heavy drinkers who avoided wine were at higher risk for death from all causes than were heavy drinkers who included wine in their alcohol intake. Wine drinkers had significantly lower mortality from both coronary heart disease and cancer than did non-wine drinkers (P = 0.007 and P = 0.004, respectively). CONCLUSION: Wine intake may have a beneficial effect on all-cause mortality that is additive to that of alcohol. This effect may be attributable to a reduction in death from both coronary heart disease and cancer.  相似文献   
129.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号