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   216134篇
  免费   3990篇
  国内免费   146篇
耳鼻咽喉   1573篇
儿科学   7967篇
妇产科学   4134篇
基础医学   22162篇
口腔科学   2012篇
临床医学   18450篇
内科学   38572篇
皮肤病学   1356篇
神经病学   20545篇
特种医学   9641篇
外国民族医学   1篇
外科学   32056篇
综合类   3067篇
一般理论   42篇
预防医学   22831篇
眼科学   3578篇
药学   12330篇
中国医学   703篇
肿瘤学   19250篇
  2023年   210篇
  2022年   385篇
  2021年   869篇
  2020年   480篇
  2019年   815篇
  2018年   22708篇
  2017年   17960篇
  2016年   20180篇
  2015年   1843篇
  2014年   2060篇
  2013年   2703篇
  2012年   9843篇
  2011年   23934篇
  2010年   20245篇
  2009年   12962篇
  2008年   22116篇
  2007年   24548篇
  2006年   3613篇
  2005年   5173篇
  2004年   6303篇
  2003年   7083篇
  2002年   5039篇
  2001年   639篇
  2000年   672篇
  1999年   529篇
  1998年   677篇
  1997年   616篇
  1996年   463篇
  1995年   456篇
  1994年   360篇
  1993年   352篇
  1992年   247篇
  1991年   286篇
  1990年   307篇
  1989年   253篇
  1988年   243篇
  1987年   193篇
  1986年   156篇
  1985年   187篇
  1984年   212篇
  1983年   205篇
  1982年   261篇
  1981年   177篇
  1980年   224篇
  1979年   112篇
  1978年   118篇
  1977年   115篇
  1976年   96篇
  1975年   78篇
  1974年   98篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
231.

Objective  

To investigate an initial approach of radiotherapy, which produces cellular radiation injury by high dose in one fraction.  相似文献   
232.
233.
234.
Patients with locally advanced, inoperable squamous cell carcinoma of the head and neck were offered three courses of cisplatin and 96-h 5-fluorouracil (5-FU) infusion. Subsequent therapy included surgery when feasible, irradiation therapy, and a maintenance program of methotrexate (MTX)-5-FU. Thirty-three patients were evaluated prospectively. Seven patients underwent a single course of chemotherapy. Five patients underwent two courses of chemotherapy. Twenty-one patients underwent three courses of adjuvant chemotherapy. The overall response rate was 48% (16 of 33). Fifteen of 21 patients (76%) receiving three courses of chemotherapy evidenced a response; this included three complete responses (CRs) (9%). No responses were seen in patients receiving only one or two courses of chemotherapy. Among responding patients, the initial favorable response to chemotherapy was apparent after the first course of chemotherapy. Patients who failed to demonstrate any response after two courses of chemotherapy did not respond after a third course. A significant group of patients fail to respond and should be offered participation in other investigational protocols as they become available.  相似文献   
235.
For patients taking two or more medications concurrently, interactions among the drugs can cause undesirable effects or negate desired responses. In modern pharmacy practice, an important role of the pharmacist is to detect potentially harmful interactions and take appropriate action to prevent their occurrence. Pharmacy computer systems offer potential for improving pharmacists' effectiveness in the detection and followup of drug interactions. Based on a survey of southern Michigan pharmacists, relationships between computer use and pharmacists' attitudes and activities in drug interaction monitoring were investigated. Respondents included users of two major computer systems as well as pharmacists who do not use computers. Results suggest that general statements cannot be made about the effect of computer use on drug interaction detection. Users of one of the two computer systems detected and followed up on interactions more frequently and were more likely to report improved knowledge of drug interactions than non-users. Frequencies of drug interaction detection and other related measures reported by users of the second computer system were similar to those for pharmacists not using computers. Computer system characteristics which might lead to these differences are discussed.  相似文献   
236.

Background  

Nasal NK/T cell lymphoma is an aggressive disease and has a poor prognosis. Nasal NK/T cell lymphoma is refractory to conventional chemotherapy and has strong tendency of widespread relapse or dissemination into distant sites.  相似文献   
237.

Background  

Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods.  相似文献   
238.
Pituitary metastases of solid tumours are infrequent, specially as a first manifestation. When they happen, they are usually due to breast or lung cancer and are asymptomatic or produce diabetes insipidus. It is very strange that they produce hormonal deficiency. We present a case report of a bronchogenic adenocarcinoma in a 65-year-old man which began with panhypopituitarism, diabetes insipidus and visual alterations. Magnetic resonance imaging revealed a large sellar mass, with clivus infiltration and invading the right cavernous sinus. The biopsy result was adenocarcinoma metastases from lung cancer.  相似文献   
239.
The rheological characterisation of glucose sensitive mixtures containing dextran and concanavalin A (con A) with and without glucose, was undertaken using oscillatory rheometry at 20 and 37 degrees C so that comparative data could be gathered in the linear viscoelastic (LVE) range. Measurements for a series of mixtures showed that complex viscosity is a function not only of the con A concentration but of the content and molecular weight of the dextran used. The extent of liquefaction on addition of glucose also depended on these factors. The tan delta profiles confirmed the change from semi-solid towards fluid behaviour. This occurs when glucose effects dismantling of the three-dimensional structure of the dextran-con A system by competitive binding to the glucose receptors in the protein. For the mixtures studied, the changes occurred between contents of 0 and 1% (w/w) glucose at 20 and 37 degrees C and form a useful basis for the formulation of a self-regulating delivery device for the control of hyper-and hypoglycaemia in diabetes.  相似文献   
240.
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