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   4410篇
  免费   387篇
  国内免费   58篇
耳鼻咽喉   39篇
儿科学   127篇
妇产科学   108篇
基础医学   385篇
口腔科学   98篇
临床医学   443篇
内科学   1023篇
皮肤病学   177篇
神经病学   169篇
特种医学   354篇
外科学   720篇
综合类   158篇
现状与发展   30篇
一般理论   1篇
预防医学   350篇
眼科学   63篇
药学   247篇
中国医学   11篇
肿瘤学   352篇
  2023年   203篇
  2022年   48篇
  2021年   141篇
  2020年   124篇
  2019年   100篇
  2018年   165篇
  2017年   158篇
  2016年   148篇
  2015年   139篇
  2014年   195篇
  2013年   220篇
  2012年   206篇
  2011年   234篇
  2010年   184篇
  2009年   166篇
  2008年   170篇
  2007年   217篇
  2006年   184篇
  2005年   173篇
  2004年   133篇
  2003年   130篇
  2002年   127篇
  2001年   55篇
  2000年   64篇
  1999年   72篇
  1998年   67篇
  1997年   66篇
  1996年   59篇
  1995年   54篇
  1994年   41篇
  1993年   47篇
  1992年   47篇
  1991年   61篇
  1990年   49篇
  1989年   52篇
  1988年   61篇
  1987年   50篇
  1986年   37篇
  1985年   45篇
  1984年   32篇
  1983年   21篇
  1982年   26篇
  1981年   23篇
  1980年   25篇
  1979年   18篇
  1978年   25篇
  1977年   16篇
  1976年   22篇
  1975年   20篇
  1974年   21篇
排序方式: 共有4855条查询结果,搜索用时 15 毫秒
1.
2.
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   
3.
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   
4.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.  相似文献   
5.
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   
6.
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   
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.
Defecography in multiple sclerosis patients with severe constipation   总被引:3,自引:0,他引:3  
Gill  KP; Chia  YW; Henry  MM; Shorvon  PJ 《Radiology》1994,191(2):553
  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