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   20338篇
  免费   1336篇
  国内免费   77篇
耳鼻咽喉   221篇
儿科学   467篇
妇产科学   459篇
基础医学   2801篇
口腔科学   1251篇
临床医学   1660篇
内科学   4699篇
皮肤病学   571篇
神经病学   1594篇
特种医学   581篇
外国民族医学   5篇
外科学   2188篇
综合类   104篇
一般理论   11篇
预防医学   2081篇
眼科学   388篇
药学   1407篇
中国医学   126篇
肿瘤学   1137篇
  2023年   178篇
  2022年   417篇
  2021年   706篇
  2020年   449篇
  2019年   594篇
  2018年   665篇
  2017年   446篇
  2016年   477篇
  2015年   599篇
  2014年   838篇
  2013年   984篇
  2012年   1493篇
  2011年   1665篇
  2010年   792篇
  2009年   684篇
  2008年   1177篇
  2007年   1190篇
  2006年   971篇
  2005年   945篇
  2004年   843篇
  2003年   757篇
  2002年   659篇
  2001年   388篇
  2000年   374篇
  1999年   313篇
  1998年   170篇
  1997年   140篇
  1996年   114篇
  1995年   79篇
  1994年   89篇
  1993年   72篇
  1992年   194篇
  1991年   177篇
  1990年   174篇
  1989年   161篇
  1988年   150篇
  1987年   156篇
  1986年   121篇
  1985年   138篇
  1984年   110篇
  1983年   92篇
  1981年   57篇
  1980年   49篇
  1979年   78篇
  1978年   58篇
  1974年   58篇
  1973年   66篇
  1972年   49篇
  1971年   58篇
  1967年   51篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
71.
In this 2 × 2 factorial, outcome-assessor blinded, feasibility randomised trial we explored the effect of a non-pharmaceutical multi-component intervention on periodontal health and metabolic and inflammatory profiles among pregnant women with periodontitis receiving prenatal care in a Brazilian public health centre. 69 pregnant women (gestational age ≤20 weeks, T0) were randomly allocated into four groups: (1) fortified sachet (vitamin D and calcium) and powdered milk plus periodontal therapy during pregnancy (early PT) (n = 17); (2) placebo sachet and powdered milk plus early PT (n = 15); (3) fortified sachet and powdered milk plus late PT (after delivery) (n = 19); (4) placebo sachet and powdered milk plus late PT (n = 18). Third trimester (T1) and 6–8 weeks postpartum (T2) exploratory outcomes included periodontal health (% sites with bleeding on probing (BOP)), glucose, insulin, C-Reactive Protein, serum calcium and vitamin D. The mean BOP was significantly reduced in the early PT groups, while BOP worsened in the late PT groups. No significant effect of fortification on BOP was observed. Changes in glucose levels and variation on birthweight did not differ among groups This feasibility trial provides preliminary evidence for estimating the minimum clinically important differences for selected maternal outcomes. A large-scale trial to evaluate the interventions’ clinical benefits and cost-effectiveness is warranted.  相似文献   
72.
73.
74.
The European Journal of Health Economics - This study aims to assess the determinants of employment probabilities among people living with Human Immunodeficiency Virus (HIV) during a 15-year period...  相似文献   
75.
76.
77.
Lasers in Medical Science - The aim of the present study was to investigate the effects of photobiomodulation (PBM) therapy on the expression of heat shock protein 70 (HSP70) and tissue repair in...  相似文献   
78.
Lasers in Medical Science - Knee osteoarthritis (KOA) is a common degenerative disease in which several treatments and treatment associations have been investigated. This review analyzed the...  相似文献   
79.
80.
Impaired nutrition status is recognized as a risk factor for worse clinical outcomes in patients with chronic obstructive pulmonary disease (COPD). The aims of this study were to investigate how undernutrition is diagnosed, its prevalence, and whether there is an association between this condition and clinical outcomes in patients with COPD. The search for this systematic review of observational studies (PROSPERO: CRD42020191888) was performed in the PubMed, Embase, and Scopus databases, with no date or language restrictions. The studies had to report data on the diagnosis of undernutrition and its association with mortality, exacerbation, length of hospital stay, or quality of life in adult patients with COPD. A meta-analysis with a random-effects model was performed to combine data. Forty-nine studies were included (20 of them classified as having a low risk of bias), and the most common diagnostic method of undernutrition was body mass index (BMI) (n = 36). The pooled prevalence of undernutrition was equal to 20% (95% CI, 0.15–0.25; I² = 100%), and it was associated with mortality (risk ratio = 1.97; 95% CI, 1.55–2.50; I² = 98%), exacerbation (risk ratio = 1.73; 95% CI, 1.03–2.91; I² = 96%), and poorer quality of life (mean difference = 8.25; 95% CI, 5.40–11.10; I² = 79%). For all outcomes, the certainty of evidence was very low. In conclusion, undernutrition is prevalent and is associated with poorer outcomes in patients with COPD. However, undernutrition is mainly diagnosed by BMI, which underreports its prevalence, and the certainty of the evidence is very low.  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