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   4006篇
  免费   251篇
  国内免费   49篇
耳鼻咽喉   25篇
儿科学   115篇
妇产科学   94篇
基础医学   398篇
口腔科学   104篇
临床医学   310篇
内科学   923篇
皮肤病学   115篇
神经病学   158篇
特种医学   371篇
外国民族医学   1篇
外科学   598篇
综合类   104篇
一般理论   1篇
预防医学   355篇
眼科学   53篇
药学   262篇
中国医学   9篇
肿瘤学   310篇
  2023年   26篇
  2022年   44篇
  2021年   127篇
  2020年   73篇
  2019年   86篇
  2018年   123篇
  2017年   126篇
  2016年   122篇
  2015年   109篇
  2014年   126篇
  2013年   188篇
  2012年   201篇
  2011年   228篇
  2010年   141篇
  2009年   124篇
  2008年   165篇
  2007年   184篇
  2006年   181篇
  2005年   169篇
  2004年   153篇
  2003年   131篇
  2002年   120篇
  2001年   51篇
  2000年   57篇
  1999年   65篇
  1998年   86篇
  1997年   79篇
  1996年   75篇
  1995年   61篇
  1994年   52篇
  1993年   50篇
  1992年   47篇
  1991年   65篇
  1990年   56篇
  1989年   44篇
  1988年   63篇
  1987年   59篇
  1986年   54篇
  1985年   43篇
  1984年   32篇
  1983年   26篇
  1982年   36篇
  1981年   16篇
  1980年   22篇
  1979年   21篇
  1978年   24篇
  1977年   18篇
  1976年   15篇
  1974年   18篇
  1973年   16篇
排序方式: 共有4306条查询结果,搜索用时 15 毫秒
1.
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed.  相似文献   
2.
Psychoactive medication use in intermediate-care facility residents   总被引:2,自引:0,他引:2  
M Beers  J Avorn  S B Soumerai  D E Everitt  D S Sherman  S Salem 《JAMA》1988,260(20):3016-3020
  相似文献   
3.
4.
A thirty six week gestation male baby weighing three kilogram was born to a twenty five year old mother by spontaneous vaginal delivery. At four hours of life, the baby developed respiratory distress with cyanosis and was admitted to the neonatal intensive care unit. There was clinical and radiological evidence of bilateral pleural effusion. Thoracentesis revealed a transudate. Repeated thoracentesis was necessary to relieve the respiratory distress. Subsequently, multi resistant Klebsiella aerogenes was isolated from the blood. The baby expired due to gram negative sepsis.  相似文献   
5.
Cancer mortality in the elderly has rarely been analyzed. It is most notably characterized by the level of diagnostic accuracy at ages prone to comorbidities. Trend analysis over the last thirty years and disparities in mortality have underscored the increasing cancer mortality in the over-65 age bracket as well as the relevance of local health context in understanding the significant differences seen throughout France.  相似文献   
6.
7.
8.
A procedure for the determination of methotrexate in human plasma is reported. The analysis involved extraction of methotrexate as an ion pair in ethyl acetate. Reconstituted residue was analyzed using reverse phase C-18 column and a mobile phase consisting of acetate buffer (87%), methanol (6.5%), and acetonitrile (6.5%). The methotrexate recovery range was 95-97%. Theophylline was used as internal standard with a recovery of 96%. The intraday coefficient of variation for the assay ranged from 1.8-3.0%, while interday variation coefficient range was 3.5-3.7%. The method is selective, reproducible, and covers a wide range of methotrexate concentrations in patient's plasma.  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