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   1611篇
  免费   102篇
  国内免费   25篇
耳鼻咽喉   4篇
儿科学   178篇
妇产科学   38篇
基础医学   124篇
口腔科学   9篇
临床医学   131篇
内科学   363篇
皮肤病学   5篇
神经病学   74篇
特种医学   20篇
外科学   59篇
综合类   157篇
预防医学   441篇
眼科学   4篇
药学   40篇
  1篇
中国医学   70篇
肿瘤学   20篇
  2024年   18篇
  2023年   38篇
  2022年   69篇
  2021年   91篇
  2020年   83篇
  2019年   83篇
  2018年   110篇
  2017年   75篇
  2016年   62篇
  2015年   66篇
  2014年   132篇
  2013年   123篇
  2012年   94篇
  2011年   119篇
  2010年   110篇
  2009年   66篇
  2008年   69篇
  2007年   67篇
  2006年   39篇
  2005年   34篇
  2004年   29篇
  2003年   19篇
  2002年   23篇
  2001年   8篇
  2000年   5篇
  1999年   8篇
  1998年   3篇
  1997年   3篇
  1996年   10篇
  1995年   3篇
  1994年   5篇
  1993年   7篇
  1992年   7篇
  1991年   3篇
  1990年   7篇
  1989年   1篇
  1988年   5篇
  1987年   7篇
  1986年   5篇
  1985年   7篇
  1984年   3篇
  1983年   2篇
  1982年   6篇
  1981年   4篇
  1980年   2篇
  1978年   2篇
  1977年   1篇
  1975年   2篇
  1974年   1篇
  1971年   2篇
排序方式: 共有1738条查询结果,搜索用时 15 毫秒
1.

Background and aims

There is controversy on the potentially benign nature of metabolically healthy obesity (MHO), i.e., obese persons with few or no metabolic abnormalities. So far, associations between MHO and coronary artery calcification (CAC), a measure of subclinical atherosclerosis, have mainly been studied cross-sectionally in Asian populations. We assessed cross-sectional and longitudinal MHO CAC associations in a Caucasian population.

Methods and results

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany, CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. For cross-sectional and longitudinal analyses, we included 1585 participants free of coronary heart disease at baseline, with CAC measurements at baseline and at follow-up, and with either normal weight (BMI 18.5–24.9 kg/m2) or obesity (BMI ≥30.0 kg/m2) at baseline. We used four definitions of MHO. In our main analysis, we defined obese persons as metabolically healthy if they met ≤1 of the NCEP ATP III criteria for the definition of the metabolic syndrome – waist circumference was not taken into account because of collinearity with BMI.Persons with MHO had a higher prevalence of CAC than metabolically healthy normal weight (MHNW) persons (prevalence ratio = 1.59 (95% confidence interval 1.38–1.84) for the main analysis). Persons with MHO had slightly larger odds of CAC progression than persons with MHNW (odds ratios ranged from 1.17 (0.69–1.99) to 1.48 (1.02–2.13) depending on MHO definition and statistical approach).

Conclusion

Our analyses on MHO CAC associations add to the evidence that MHO is not a purely benign health condition.  相似文献   
2.
3.
IntroductionMost anthropometric reference data for extremely preterm infants used in Spain are outdated and based on non-Spanish populations, or are derived from small hospital-based samples that failed to include neonates of borderline viability.ObjectivesTo develop gender-specific, population-based curves for birth weight, length, and head circumference in extremely preterm Caucasian infants, using a large contemporary sample size of Spanish singletons.Patients and methodsAnthropometric data from neonates ≤ 28 weeks of gestational age were collected between January 2002 and December 2010 using the Spanish database SEN1500. Gestational age was estimated according to obstetric data (early pregnancy ultrasound). The data were analyzed with the SPSS.20 package, and centile tables were created for males and females using the Cole and Green LMS method.ResultsThis study presents the first population-based growth curves for extremely preterm infants, including those of borderline viability, in Spain. A sexual dimorphism is evident for all of the studied parameters, starting at early gestation.ConclusionsThese new gender-specific and population-based data could be useful for the improvement of growth assessments of extremely preterm infants in our country, for the development of epidemiological studies, for the evaluation of temporal trends, and for clinical or public health interventions seeking to optimize fetal growth.  相似文献   
4.
Obesity: epidemiology and possible prevention   总被引:5,自引:0,他引:5  
Obesity can be defined as the excessive accumulation of fat in adipose tissue, to the extent that health may be impaired. The most widely used measures of total and abdominal adiposity are the body mass index and waist circumference. Obesity is now a global public health problem, with about 315 million people world-wide estimated to fall into the WHO-defined obesity categories with a body mass index (BMI) of 30 or above.The primary causes of the rapid global rise in obesity rates lie in the profound environmental and societal changes now affecting large parts of the world and creating societies in which physical activity is low and the availability of high-fat, energy-dense foods has increased. Strategies aimed at preventing weight gain and obesity have not been successful to date but are likely to be more cost effective, and to have a greater positive impact on long-term control of body weight than treating obesity once it has developed.  相似文献   
5.
韩延柏 《中国公共卫生》2015,31(11):1464-1466
目的 探讨辽宁省20~69岁成人肥胖指标的特征与一致性。方法 分析第3次国民体质监测辽宁省抽样点5817名成人的数据资料,描述性别、年龄别腰围身高比(WHtR)、腰围(WC)、腰臀比(WHR)和体质指数(BMI)的分布。结果 男性WHtR、WC和BMI随年龄而升高,60岁~组降低;女性WHtR、WC、WHR和BMI随年龄而升高,60岁~组最高。BMI和WHtR、BMI和WC判定肥胖的一致性一般,并随年龄增大而降低,kappa值由20岁~组的0.63~0.68降低至60岁~组的0.48~0.51。使用BMI的错误分类率随年龄增大而增加,在60岁~组,BMI正常的WHtR中心性肥胖者漏诊率男性为35.7% (51/143),女性为54.9% (73/133),BMI正常的WC中心性肥胖者漏诊率男性为26.6% (38/143),女性为42.9% (57/133)。结论 成人肥胖指标的分布随年龄而变化;BMI结合WHtR或WC能够提高鉴别肥胖的效果,对>60岁人群尤为重要。  相似文献   
6.
7.
Aim. Previous studies support the concept that obesity is a common comorbid condition in patients with epilepsy (PWE). In this study, we present the body mass index (BMI) and data from a survey to assess physical activity in a sample of PWE from an epilepsy clinic. Methods. Between June of 2011 and January of 2013, 100 PWE from an adult epilepsy clinic were included. We obtained BMI, waist circumference, and information regarding physical activity using a standardised questionnaire. Clinical, demographic, electrographic, and imaging parameters were collected from charts. Results. Mean age of patients was 40±14 (18–77) years. The BMI distribution was as follows: 2 patients (2%) underweight, 26 (26%) normal weight, 34 (34%) overweight, 25 (25%) obese, and 13 (13%) with morbid obesity. In our study, obesity was defined as having a BMI ≥30. We found 38 (38%) patients in this range. There was no difference in the rate of drug‐resistant epilepsy between obese and non‐obese patients (55 vs. 55%; p=0.05). Leisure time habit was reported in 82% of obese patients and 79% of patients without obesity. Overall, the most frequent activity was walking (70%). Factors associated with obesity were generalised epilepsy (OR: 2.7, 1.1–6.6; p=0.012), idiopathic syndrome (OR: 2.7, 1.04–7; p=0.018), and family history of epilepsy (OR: 6.1, 1.5–24.2; p=0.002). Conclusion. Our study suggests an association between obesity, idiopathic generalised epilepsy, and family history of epilepsy. Our study shows that PWE are physically active and there is no clear relation between exercise and obesity. We could not identify any association between drug‐resistant epilepsy and obesity. Absence of direct comparison with a control non‐epileptic population; a cross‐sectional design not allowing evaluation of a causal association among variables; and reliance on self‐reported physical activity are to be considered as limitations of the present study.  相似文献   
8.
9.
Background: Obesity relates to impaired olfactory function. Abnormal olfactory function is also associated with poor diet; however, whether obesity-related markers shape this relationship is unknown. Methods: Cross-sectional analysis (n = 1415, age > 40 years) of NHANES 2013–2014 examined body fat percent (BF%) and waist circumference (WC) as moderators of the relationship between olfactory function and diet. The olfactory function test identified adults with olfactory dysfunction (OD) or normal olfaction (NO). Validated 24 h recall captured nutrient intake and Healthy Eating Index-2010 scores. BF% and WC were measured. We tested adjusted linear regression models, with an interaction term between olfactory function and BF%/WC, for each nutrient or HEI score, and reported coefficients (β), standard errors (SE), and p-values for significant interaction terms. Results: In OD (9.5%; mean age 50.9 years, 95% CI 49.6, 52.2) compared with NO (mean age 49.3 years, 95% CI 48.8, 49.9), higher BF% was associated with higher intake of saturated fat (β (SE): 0.2 (0.1) g; p = 0.06) and percent of total calories from total fat (0.2 (0.1); p = 0.07), saturated (0.1 (0.004); p = 0.02), and monounsaturated fat (0.1 (0.1); p = 0.08); lower percent of total calories from carbohydrates (−0.2 (0.1); p = 0.09) and mg of sodium (−17.8 (09.6); p = 0.08); and a higher (healthier) refined grain score (0.1 (0.1); p = 0.04). Higher WC was associated with higher refined grain scores (0.01 (0.02); p = 0.01) in OD. Conclusion: BF% may shape dietary intake and quality in OD. Longitudinal studies are needed to elucidate the directionality of these relationships and develop strategies to improve dietary intake among OD.  相似文献   
10.
目的了解正常高值血压及高血压人群血脂、血糖、腰围水平对血压的影响因素,加强对高血压尤其是正常高值血压的防治。方法采用多阶段随机整群抽样的方法,在深圳市抽取73个社区,在每个社区中随机抽取120户居民,最终共8 601人进入研究。对研究对象进行问卷调查、人体测量、血液生化检测和膳食调查四部分调查。结果血压正常者、正常高值血压者和高血压者各占65.77%,19.79%和14.44%。高血压组腰围、BMI值、总胆固醇、甘油三酯和空腹血糖值均最大,正常高值血压组次之,正常血压组均最小。多因素Logistic回归分析结果显示高血压及正常高值血压有相同的影响因素,均为性别、年龄、腰围、空腹血糖、低密度脂蛋白、甘油三酯、BMI。结论血脂、血糖、腰围与血压关系密切,正常高值血压人群的健康状况值得关注。  相似文献   
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