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   68562篇
  免费   4975篇
  国内免费   164篇
耳鼻咽喉   877篇
儿科学   1840篇
妇产科学   1681篇
基础医学   11141篇
口腔科学   1783篇
临床医学   6319篇
内科学   14042篇
皮肤病学   1031篇
神经病学   6414篇
特种医学   2860篇
外国民族医学   46篇
外科学   8926篇
综合类   634篇
一般理论   83篇
预防医学   5337篇
眼科学   1298篇
药学   4891篇
中国医学   186篇
肿瘤学   4312篇
  2021年   1092篇
  2020年   692篇
  2019年   1002篇
  2018年   1194篇
  2017年   860篇
  2016年   999篇
  2015年   1161篇
  2014年   1493篇
  2013年   2529篇
  2012年   3308篇
  2011年   3378篇
  2010年   2393篇
  2009年   2007篇
  2008年   3022篇
  2007年   3177篇
  2006年   3199篇
  2005年   3016篇
  2004年   3074篇
  2003年   2843篇
  2002年   2927篇
  2001年   2408篇
  2000年   2497篇
  1999年   2195篇
  1998年   947篇
  1997年   777篇
  1996年   700篇
  1995年   710篇
  1994年   598篇
  1993年   651篇
  1992年   1540篇
  1991年   1485篇
  1990年   1420篇
  1989年   1396篇
  1988年   1174篇
  1987年   1177篇
  1986年   1111篇
  1985年   1006篇
  1984年   729篇
  1983年   678篇
  1982年   476篇
  1981年   465篇
  1980年   395篇
  1979年   653篇
  1978年   394篇
  1977年   380篇
  1975年   388篇
  1974年   433篇
  1973年   368篇
  1972年   363篇
  1971年   314篇
排序方式: 共有10000条查询结果,搜索用时 15 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