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   65834篇
  免费   4916篇
  国内免费   157篇
耳鼻咽喉   846篇
儿科学   1865篇
妇产科学   1632篇
基础医学   10878篇
口腔科学   1823篇
临床医学   6220篇
内科学   13237篇
皮肤病学   1021篇
神经病学   6101篇
特种医学   2811篇
外国民族医学   46篇
外科学   8428篇
综合类   589篇
一般理论   86篇
预防医学   5182篇
眼科学   1271篇
药学   4691篇
中国医学   168篇
肿瘤学   4012篇
  2022年   394篇
  2021年   1045篇
  2020年   670篇
  2019年   945篇
  2018年   1166篇
  2017年   818篇
  2016年   965篇
  2015年   1136篇
  2014年   1395篇
  2013年   2426篇
  2012年   3085篇
  2011年   3167篇
  2010年   2329篇
  2009年   1961篇
  2008年   2905篇
  2007年   3036篇
  2006年   3022篇
  2005年   2889篇
  2004年   2922篇
  2003年   2657篇
  2002年   2728篇
  2001年   2302篇
  2000年   2383篇
  1999年   2072篇
  1998年   938篇
  1997年   780篇
  1996年   708篇
  1995年   725篇
  1994年   594篇
  1993年   643篇
  1992年   1479篇
  1991年   1422篇
  1990年   1362篇
  1989年   1364篇
  1988年   1136篇
  1987年   1131篇
  1986年   1082篇
  1985年   998篇
  1984年   719篇
  1983年   671篇
  1982年   469篇
  1981年   462篇
  1980年   395篇
  1979年   635篇
  1978年   385篇
  1977年   369篇
  1975年   383篇
  1974年   420篇
  1973年   356篇
  1972年   346篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
3.
4.
5.
6.
Clinical Oral Investigations - The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of...  相似文献   
7.
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade.  相似文献   
8.
Genetic and epigenetic alterations importantly contribute to the pathogenesis of lung cancer. In the study, we measured the frequency and distribution of molecular abnormalities of EGFR as well as the aberrant promoter methylations of BRCA1, MGMT, MLH1, and RASSF1A in Vietnamese lung adenocarcinomas. We investigated the association between genetic and epigenetic alteration, and between each abnormality with clinicopathologic parameters. Somatic EGFR mutation that was found in 49/139 (35.3%) lung adenocarcinomas showed a significant association with young age, female gender, and non-smokers. EGFR overexpression was identified in 82 tumors (59.0%) and statistical relationships with EGFR or BRCA1 methylation but not EGFR mutation. In addition, EGFR, BRCA1, MGMT, MLH1, and RASSF1A methylations were found in 33 (23.7%), 41 (29.5%), 46 (33.1%), 28 (20.1%), and 41 (29.5%) cases of a total of 139 lung adenocarcinomas, respectively. The RASSF1A methylation was found to be linked to the smoking habit. Methylations in MGMT and RASSF1A were also found to correlate with metastasis status. Furthermore, the distribution of EGFR mutation and that of BRCA1, MGMT or RASSF1A methylation were significantly exclusive in lung adenocarcinomas. The main finding of our study demonstrate that epigenetic abnormalities might play a critical role for the lung tumorigenesis in patients with smoking history and metastasis, and partly affect the predictive value of EGFR mutations through blocking expression due to promoter EGFR hypermethylation. Mutually exclusive distribution of genetic and epigenetic alterations reflects differently biological characteristics in the etiology of lung adenocarcinomas.  相似文献   
9.
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