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   384183篇
  免费   25509篇
  国内免费   3145篇
耳鼻咽喉   5243篇
儿科学   8264篇
妇产科学   10148篇
基础医学   53666篇
口腔科学   11874篇
临床医学   30983篇
内科学   78969篇
皮肤病学   8594篇
神经病学   27434篇
特种医学   14084篇
外国民族医学   88篇
外科学   61025篇
综合类   11351篇
现状与发展   5篇
一般理论   65篇
预防医学   17935篇
眼科学   9631篇
药学   31667篇
  10篇
中国医学   2564篇
肿瘤学   29237篇
  2021年   2911篇
  2019年   2909篇
  2018年   4713篇
  2017年   3655篇
  2016年   3699篇
  2015年   4311篇
  2014年   6042篇
  2013年   7804篇
  2012年   10548篇
  2011年   10689篇
  2010年   6633篇
  2009年   6211篇
  2008年   9855篇
  2007年   10656篇
  2006年   10506篇
  2005年   9526篇
  2004年   8988篇
  2003年   8682篇
  2002年   8324篇
  2001年   28385篇
  2000年   28855篇
  1999年   23713篇
  1998年   5191篇
  1997年   4277篇
  1996年   3848篇
  1995年   3496篇
  1994年   3120篇
  1993年   2845篇
  1992年   16054篇
  1991年   14817篇
  1990年   14160篇
  1989年   13966篇
  1988年   12586篇
  1987年   12061篇
  1986年   11105篇
  1985年   10320篇
  1984年   6912篇
  1983年   5600篇
  1982年   2718篇
  1979年   5478篇
  1978年   3347篇
  1977年   2971篇
  1975年   2641篇
  1974年   3065篇
  1973年   2867篇
  1972年   2828篇
  1971年   2773篇
  1970年   2511篇
  1969年   2543篇
  1968年   2250篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Harinakshi Sanikini  David C. Muller  Marisa Sophiea  Sabina Rinaldi  Antonio Agudo  Eric J. Duell  Elisabete Weiderpass  Kim Overvad  Anne Tjønneland  Jytte Halkjær  Marie-Christine Boutron-Ruault  Franck Carbonnel  Iris Cervenka  Heiner Boeing  Rudolf Kaaks  Tilman Kühn  Antonia Trichopoulou  Georgia Martimianaki  Anna Karakatsani  Valeria Pala  Domenico Palli  Amalia Mattiello  Rosario Tumino  Carlotta Sacerdote  Guri Skeie  Charlotta Rylander  María-Dolores Chirlaque López  Maria-Jose Sánchez  Eva Ardanaz  Sara Regnér  Tanja Stocks  Bas Bueno-de-Mesquita  Roel C.H. Vermeulen  Dagfinn Aune  Tammy Y.N. Tong  Nathalie Kliemann  Neil Murphy  Marc Chadeau-Hyam  Marc J. Gunter  Amanda J. Cross 《International journal of cancer. Journal international du cancer》2020,146(4):929-942
Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5–25 kg/m2: HR = 1.94, 95% CI: 1.25–3.03) and women (HR = 2.66, 95% CI: 1.15–6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99–6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52–4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35–14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76–18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14–0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32–0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04–3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers.  相似文献   
43.
44.
45.
46.
蒋巍  孙育民  李颖  王蓓  薛元媛  王骏 《心脏杂志》2015,27(2):249-250
1临床资料患者,男,43岁,因"四肢近端肌肉无力9个月,加剧1周"于2013年9月22日入院。患者于9个月前无明显诱因下出现四肢肌肉无力,以近端肌力减退为主,主要表现为上楼梯费力,提重物困难,易疲劳,尚可参加工作,无发热、皮疹、肌痛、感觉异常等,无明显晨轻暮重的波动现象,上述症状逐渐加重,劳动耐量和日常生活能力进行性下  相似文献   
47.
48.
BackgroundWomen suffering from kidney disease are more prone to fertility problems, due to uremia. Fortunately, their fertility rate increases dramatically after renal transplantation. This study analyzes the predictors/risk factors of successful pregnancy with live birth outcome while presenting an overview of the 7-year experience of a single center.MethodsThis retrospective cohort study includes 239 women of reproductive age (18–40 years) who underwent renal transplantation in a tertiary Turkish clinic between October 1, 2011, and August 24, 2017. The subjects were invited to take part in a survey questioning their obstetric characteristics and they were assessed in 2 groups: fertile and infertile. Multivariable linear regression analysis was conducted to determine the predictors of a successful pregnancy.ResultsThirty-five 35 patients wished to become pregnant: 12 got pregnant spontaneously, while 21 failed to become pregnant (spontaneously). The mean age of the patients at the survey was 34 ± 7. Regular menstrual cycles after renal transplantation, tacrolimus-mycophenolate mofetil maintenance protocol, and age at transplantation were found to be predictors of spontaneous pregnancy. The duration of peritoneal dialysis was significantly longer in the infertile group (48 vs 12 months).ConclusionEnd-stage renal disease's negative impacts, including menstrual abnormality and fertility problems, can be overcome by successful kidney transplantation with appropriate immunosuppression. Minimizing the duration of peritoneal dialysis, particularly in patients who desire future fertility, may be accepted as a logical management strategy.  相似文献   
49.
50.
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