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   927563篇
  免费   67422篇
  国内免费   1314篇
耳鼻咽喉   12969篇
儿科学   24315篇
妇产科学   23236篇
基础医学   132288篇
口腔科学   28269篇
临床医学   80133篇
内科学   182158篇
皮肤病学   19419篇
神经病学   71805篇
特种医学   36801篇
外国民族医学   79篇
外科学   151846篇
综合类   18008篇
一般理论   234篇
预防医学   61342篇
眼科学   21260篇
药学   72385篇
  3篇
中国医学   2133篇
肿瘤学   57616篇
  2018年   8974篇
  2017年   7051篇
  2016年   7748篇
  2015年   8855篇
  2014年   12010篇
  2013年   17535篇
  2012年   24138篇
  2011年   25110篇
  2010年   14842篇
  2009年   14305篇
  2008年   24645篇
  2007年   25724篇
  2006年   26515篇
  2005年   25485篇
  2004年   24603篇
  2003年   23646篇
  2002年   23176篇
  2001年   54709篇
  2000年   56485篇
  1999年   46800篇
  1998年   10289篇
  1997年   8999篇
  1996年   9154篇
  1995年   8905篇
  1994年   8270篇
  1993年   7587篇
  1992年   35500篇
  1991年   33951篇
  1990年   32763篇
  1989年   31896篇
  1988年   29002篇
  1987年   28279篇
  1986年   26298篇
  1985年   25159篇
  1984年   17840篇
  1983年   15137篇
  1982年   7769篇
  1981年   6752篇
  1979年   15777篇
  1978年   10591篇
  1977年   9037篇
  1976年   7865篇
  1975年   8633篇
  1974年   10465篇
  1973年   9854篇
  1972年   9363篇
  1971年   8855篇
  1970年   8419篇
  1969年   7929篇
  1968年   7208篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was ?8.13 kg [95%CI ?9.01; ?7.26]. FFM loss and SMM loss were ?8.23 kg [95%CI ?10.74; ?5.73] and ?3.18 kg [95%CI ?5.64; ?0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.  相似文献   
3.
Tobacco smoking is associated with a substantially increased risk of postoperative complications. The peri-operative period offers a unique opportunity to support patients to stop tobacco smoking, avoid complications and improve long-term health. This systematic review provides an up-to-date summary of the evidence for tobacco cessation interventions in surgical patients. We conducted a systematic search of randomised controlled trials of tobacco cessation interventions in the peri-operative period. Quantitative synthesis of the abstinence outcomes data was by random-effects meta-analysis. The primary outcome of the meta-analysis was abstinence at the time of surgery, and the secondary outcome was abstinence at 12 months. Thirty-eight studies are included in the review (7310 randomised participants) and 26 studies are included in the meta-analysis (5969 randomised participants). Studies were pooled for subgroup analysis in two ways: by the timing of intervention delivery within the peri-operative period and by the intensity of the intervention protocol. We judged the quality of evidence as moderate, reflecting the degree of heterogeneity and the high risk of bias. Overall, peri-operative tobacco cessation interventions increased successful abstinence both at the time of surgery, risk ratio (95%CI) 1.48 (1.20–1.83), number needed to treat 7; and 12 months after surgery, risk ratio (95%CI) 1.62 (1.29–2.03), number needed to treat 9. More work is needed to inform the design and optimal delivery of interventions that are acceptable to patients and that can be incorporated into contemporary elective and urgent surgical pathways. Future trials should use standardised outcome measures.  相似文献   
4.
Human papillomavirus (HPV) vaccine effectiveness may differ between settings. Here we present the first real-world effectiveness study of HPV vaccination on high-grade cervical lesions from Norway, among women who received HPV vaccine outside the routine program. We performed an observational study of all Norwegian women born 1975 to 1996 and retrieved individual data from nationwide registries on HPV vaccination status and incidence of histologically verified high-grade cervical neoplasia during 2006 to 2016. We estimated the incidence rate ratio (IRR) and 95% confidence intervals (CI) for vaccination vs no vaccination by Poisson regression stratified by age at vaccination <20 years and ≥20 years. The cohort consisted of 832 732 women, of which 46 381 (5.6%) received at least one dose of HPV vaccine by the end of 2016. The incidence rate of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) increased with age regardless of vaccination status and was highest at age 25 to 29, at 637/100 000 among unvaccinated women, 487/100 000 among women vaccinated before age 20 and 831/100 000 among women vaccinated at age 20 or older. The adjusted IRR of CIN2+ between vaccinated and unvaccinated women was 0.62 (95% CI: 0.46-0.84) for women vaccinated below age 20, and 1.22 (95% CI: 1.03-1.43) for women vaccinated at age 20 or older. These findings indicate that HPV vaccination among women too old to be eligible for routine HPV vaccination is effective among women who are vaccinated below age 20 but may not have the desired impact among women who are vaccinated at age 20 or older.  相似文献   
5.
6.
7.
8.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
9.
Clinical Oral Investigations - The objective of this systematic review and meta-analysis (SRM) was to answer the question whether the use of ultrasonic irrigation (UI) results in less postoperative...  相似文献   
10.
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