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   3379篇
  免费   368篇
  国内免费   11篇
耳鼻咽喉   18篇
儿科学   185篇
妇产科学   82篇
基础医学   475篇
口腔科学   79篇
临床医学   443篇
内科学   724篇
皮肤病学   27篇
神经病学   294篇
特种医学   371篇
外科学   207篇
综合类   54篇
预防医学   425篇
眼科学   36篇
药学   212篇
肿瘤学   126篇
  2022年   19篇
  2021年   35篇
  2020年   30篇
  2019年   41篇
  2018年   42篇
  2017年   25篇
  2016年   33篇
  2015年   50篇
  2014年   78篇
  2013年   92篇
  2012年   114篇
  2011年   119篇
  2010年   83篇
  2009年   81篇
  2008年   84篇
  2007年   136篇
  2006年   129篇
  2005年   128篇
  2004年   96篇
  2003年   122篇
  2002年   94篇
  2001年   96篇
  2000年   91篇
  1999年   80篇
  1998年   124篇
  1997年   92篇
  1996年   102篇
  1995年   70篇
  1994年   86篇
  1993年   85篇
  1992年   67篇
  1991年   64篇
  1990年   73篇
  1989年   90篇
  1988年   75篇
  1987年   88篇
  1986年   61篇
  1985年   82篇
  1984年   62篇
  1983年   44篇
  1982年   45篇
  1981年   40篇
  1980年   41篇
  1979年   42篇
  1978年   50篇
  1977年   43篇
  1976年   44篇
  1975年   39篇
  1974年   39篇
  1973年   33篇
排序方式: 共有3758条查询结果,搜索用时 15 毫秒
1.
2.
Needle-localized breast biopsy: why do we fail?   总被引:10,自引:0,他引:10  
Jackman  RJ; Marzoni  FA  Jr 《Radiology》1997,204(3):677
  相似文献   
3.
4.
In recent trials in The Gambia, mass chemoprophylaxis with Maloprim administered over several years by primary health care workers to children aged 3-59 months has reduced both mortality and morbidity without inducing impairment of natural immunity or significant development of drug resistance. Taking expenditure of both time and money, by both public authorities and village volunteers, into account, the costs and the cost effectiveness of such mass chemoprophylaxis are estimated here. The cost per child protected per season was (1990 US) $2.84; the cost per childhood death averted was $143. Both costs compare favourably with those of permethrin bed net impregnation. So in some circumstances where malaria is holoendemic, control of childhood malaria by chemoprophylaxis may be more economically efficient than provision of impregnated bed nets.  相似文献   
5.
6.
7.
The current WHO recommendations for the case management of acute respiratory infections (ARI) in children aged 2 months to 5 years in developing countries use fast breathing (respiratory rate of > or = 50 per minute in children under 12 months and > or = 40 in children aged 12 months to 5 years) and lower chest wall indrawing to determine which child is likely to have pneumonia and should therefore receive antibiotics. We have evaluated these and other physical signs in 487 malnourished children and 255 well nourished children who presented with a cough or breathing difficulty. Pneumonia, defined as definite radiological pneumonia or probable radiological pneumonia associated with crackles on auscultation, was present in 145 (30%) of the malnourished children and 68 (26%) of the well nourished children. The respiratory rate predicted pneumonia equally well in the two groups, but to achieve an appropriate sensitivity and specificity the respiratory rate cut-off required in malnourished children was approximately 5 breaths per minute less than that in well nourished children. Intercostal indrawing was more common and lower chest wall indrawing was less common in the malnourished children, with or without pneumonia. These results suggest that fast breathing, as defined at present by WHO, and lower chest wall indrawing are not sufficiently sensistive as predictors of pneumonia in malnourished children. As the latter are a high-risk group, we should like to recommend that children with malnutrition who present with a cough, fast breathing or difficult breathing should be treated with antibiotics.  相似文献   
8.
荧光原位杂交技术分析人结肠菌群方法研究   总被引:2,自引:0,他引:2  
建立荧光原位杂交技术分析人体内结肠菌群的方法。取受试者新鲜粪便 ,选用 5种特异性的 16SrRNA寡核苷酸探针 ,检测粪便样本收集后的保存时间、温度 ,离心条件及样本固定液存放时间对杂交计数结果的影响。结果建立最佳实验条件为 :粪便样本收集后应尽快在 4℃下保存 ,放置时间不要超过 12小时即作处理 ;样本的适宜离心条件为 70 0g 2分钟 ;样本用多聚甲醛固定后在 - 80℃下存放时间不要超过 5个月。该方法具有较好的稳定性 ,可以有效地检出个体之间结肠菌群的差异。  相似文献   
9.
Methsuximide for intractable childhood seizures   总被引:1,自引:0,他引:1  
Methsuximide was added to the therapeutic regimens of 25 children with intractable epilepsy. In 15 patients the drug was well tolerated and resulted in a 50% or greater reduction in seizure frequency. No serious or irreversible adverse effects were seen. Methsuximide is frequently overlooked and may be an effective adjunctive antiepileptic for children with intractable seizures.  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