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   1759篇
  免费   189篇
  国内免费   63篇
耳鼻咽喉   16篇
儿科学   73篇
妇产科学   41篇
基础医学   296篇
口腔科学   39篇
临床医学   188篇
内科学   314篇
皮肤病学   30篇
神经病学   64篇
特种医学   295篇
外科学   140篇
综合类   117篇
一般理论   2篇
预防医学   128篇
眼科学   11篇
药学   178篇
肿瘤学   79篇
  2021年   21篇
  2018年   14篇
  2017年   15篇
  2016年   19篇
  2015年   23篇
  2014年   27篇
  2013年   43篇
  2012年   29篇
  2011年   40篇
  2010年   40篇
  2009年   47篇
  2008年   45篇
  2007年   70篇
  2006年   58篇
  2005年   63篇
  2004年   37篇
  2003年   49篇
  2002年   38篇
  2001年   54篇
  2000年   52篇
  1999年   61篇
  1998年   71篇
  1997年   78篇
  1996年   68篇
  1995年   77篇
  1994年   46篇
  1993年   59篇
  1992年   56篇
  1991年   58篇
  1990年   50篇
  1989年   67篇
  1988年   63篇
  1987年   57篇
  1986年   34篇
  1985年   43篇
  1984年   34篇
  1983年   14篇
  1982年   27篇
  1981年   24篇
  1980年   31篇
  1979年   26篇
  1978年   9篇
  1977年   21篇
  1976年   14篇
  1975年   11篇
  1974年   9篇
  1973年   11篇
  1971年   8篇
  1969年   9篇
  1968年   9篇
排序方式: 共有2011条查询结果,搜索用时 7 毫秒
11.
12.
Between 1971 and 1985, 598 patients with ovarian carcinoma were treated with abdomino-pelvic radiation therapy. Acute complications included nausea and vomiting in 364 patients (61%) which were severe in 36, and diarrhea in 407 patients (68%), severe in 35. Leukopenia (less than 2.0 x 10(9) cells/liter) and thrombocytopenia (less than 100 x 10(9) cells/liter) occurred in 64 patients (11%) each. Treatment interruptions occurred in 136 patients (23%), and 62 patients (10%) did not complete treatment. In both situations the most common cause was myelosuppression. Late complications included chronic diarrhea in 85 patients (14%), transient hepatic enzyme elevation in 224 (44%), and symptomatic basal pneumonitis in 23 (4%). Serious late bowel complications were infrequent: 25 patients (4.2%) developed bowel obstruction and 16 required operation. Multivariate analysis was unable to determine any significant prognostic factors for bowel obstruction; however, the moving-strip technique of radiation therapy was associated with a significantly greater risk of developing chronic diarrhea, pneumonitis, and hepatic enzyme elevation than was the open beam technique. We conclude that abdomino-pelvic radiation therapy as used in these patients is associated with modest acute complications and a low risk of serious late toxicity.  相似文献   
13.
14.
Tuberculosis remained a very significant cause of death in Ireland until the mid-20th century and still occupies a prominent position in the folk memory. As I show with reference to recent Irish media coverage, the global resurgence of tuberculosis is therefore viewed with concern in Ireland. Using data collated by the Health Protection Surveillance Centre between 1998 and 2005 however, I show that the recent increase in tuberculosis incidence in Ireland is less than is popularly perceived. This increase is largely associated with economic immigrants attracted to Ireland by the ‘Celtic Tiger’ economic boom, but there is little evidence to suggest that this has had a negative impact on the Irish-born population. Drug resistance is still a small but growing problem. Whilst vigilance is required, it is argued that the recent increase does not at present indicate a likely return to the situation in the mid-20th century.  相似文献   
15.
16.
大狼毒三萜类化学成分的研究   总被引:3,自引:0,他引:3  
曹东  苏亚伦  杨峻山 《药学学报》1992,27(6):445-451
自大戟科(Euphorbiaceae)植物大狼毒(Euphorbia nematocypha Hand—Mazz)根的乙醇提取物的苯溶解部分,经20%AgNO3硅胶层析,分离得到七个三萜类成分。根据光谱(IR,EIMS,1H—NMR和13C—NMR)和化学方法,确定其中一个化合物为新化合物,命名为大狼毒醇(nematocyphol,Ⅳa),其它化合物为已知物:印度荆芥醇乙酸酯(nepehinol acetate Ⅰ),日尔曼醇乙酸酯(germanicol acetate Ⅱ),大戟醇(euphol,Ⅲ),蒲公英醇(taraxasterol,Ⅴa),24-亚甲基环阿尔廷醇(24-methylenecycloartanol,Ⅴa)和印度荆芥醇(nepehinol,Ⅶa)。这些化合物均为首次从大狼毒中得到。  相似文献   
17.
A questionnaire survey of the 44 general practices in Central Nottinghamshire Health District elicited 43 responses. Ten scenarios on sharing information were graded on a five point scale by each practice according to its willingness to share the information. Responses varied from 41 practices that would at least "probably" give the number of their young chronic sick patients to the local district health authority to 17 practices that were positive towards sharing with a local charity the names of elderly patients living alone. This second example raises profound issues of confidentiality. The extent to which practices were prepared theoretically to share practice generated information with outside bodies was generally high and showed a willingness to do so if the reasons were sound and the requesting body was acceptable.  相似文献   
18.
19.
20.
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