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   35341篇
  免费   3034篇
  国内免费   53篇
耳鼻咽喉   383篇
儿科学   1342篇
妇产科学   1011篇
基础医学   4804篇
口腔科学   781篇
临床医学   4991篇
内科学   6269篇
皮肤病学   496篇
神经病学   3041篇
特种医学   999篇
外国民族医学   1篇
外科学   3458篇
综合类   1064篇
一般理论   46篇
预防医学   4496篇
眼科学   590篇
药学   2384篇
中国医学   31篇
肿瘤学   2241篇
  2022年   260篇
  2021年   588篇
  2020年   378篇
  2019年   593篇
  2018年   659篇
  2017年   500篇
  2016年   593篇
  2015年   689篇
  2014年   910篇
  2013年   1413篇
  2012年   1943篇
  2011年   2036篇
  2010年   1101篇
  2009年   992篇
  2008年   1862篇
  2007年   1986篇
  2006年   1967篇
  2005年   1848篇
  2004年   1838篇
  2003年   1718篇
  2002年   1676篇
  2001年   750篇
  2000年   748篇
  1999年   667篇
  1998年   457篇
  1997年   383篇
  1996年   393篇
  1995年   373篇
  1994年   314篇
  1993年   330篇
  1992年   528篇
  1991年   498篇
  1990年   503篇
  1989年   512篇
  1988年   503篇
  1987年   388篇
  1986年   419篇
  1985年   452篇
  1984年   335篇
  1983年   287篇
  1982年   233篇
  1981年   249篇
  1980年   207篇
  1979年   274篇
  1978年   236篇
  1977年   250篇
  1976年   218篇
  1974年   211篇
  1973年   203篇
  1972年   190篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
PURPOSE: Epidermal growth factor receptor is expressed in pediatric malignant solid tumors. We conducted a phase I trial of gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, in children with refractory solid tumors. PATIENTS AND METHODS: Gefitinib (150, 300, 400, or 500 mg/m2) was administered orally to cohorts of three to six patients once daily continuously until disease progression or significant toxicity. Pharmacokinetic studies were performed during course one (day 1 through 28). RESULTS: Of the 25 enrolled patients, 19 (median age, 15 years) were fully evaluable for toxicity and received 54 courses. Dose-limiting toxicity was rash in two patients treated with 500 mg/m2 and elevated ALT and AST in one patient treated with 400 mg/m2. The maximum-tolerated dose was 400 mg/m2/d. The most frequent non-dose-limiting toxicities were grade 1 or 2 dry skin, anemia, diarrhea, nausea, and vomiting. One patient with Ewing's sarcoma had a partial response. Disease stabilized for 8 to > or = 60 weeks in two patients with Wilms' tumor and two with brainstem glioma (one exophytic). At 400 mg/m2, the median peak gefitinib plasma concentration was 2.2 microg/mL (range, 1.2 to 3.6 microg/mL) and occurred at a median of 2.3 hours (range, 2.0 to 8.3 hours) after drug administration. The median apparent clearance and median half-life were 14.8 L/h/m2 (range, 3.8 to 24.8 L/h/m2) and 11.7 hours (range, 5.6 to 22.8 hours), respectively. Gefitinib systemic exposures were comparable with those associated with antitumor activity in adults. CONCLUSION: Oral gefitinib is well tolerated in children. Development of the drug in combination with cytotoxic chemotherapy will be pursued.  相似文献   
12.

Background  

Health service policy in the United Kingdom emphasises the importance of self-care by patients with chronic conditions. Written information for patients about their condition is seen as an important aid to help patients look after themselves. From a discourse analysis perspective written texts such as patient information leaflets do not simply describe the reality of a medical condition and its management but by drawing on some sorts of knowledge and evidence rather than others help construct the reality of that condition. This study explored patient information leaflets on osteoarthritis (OA) to see how OA was constructed and to consider the implications for self-care.  相似文献   
13.
Objectives: Heavy smokers are a segment of the smoking population who are at increased risk of smoking-related morbidity and least likely to achieve cessation. This study identifies the impact of heavy smoking on quality of life by gender and describes the subpopulation for improved targeting.Methods: South Australian representative population data (n = 3010) was used to compare the health-related quality of life status of male and female heavy smokers as assessed by the SF-36.  相似文献   
14.
15.
16.
17.
18.
19.
The investigation of AUSTROLIABUM CANDIDUM afforded, in addition to several known sesquiterpene lactones, four new ones, including three germacranolides with an ether bridge, as well as an unusual glucoside. The structures were elucidated by spectroscopic methods.  相似文献   
20.
This study examined the use and effectiveness of the Alert assessment form. The form is part of the Alert system, used by one large acute care hospital to identify patients with a propensity for violence. All reported incidents of patient violence from August 1, 2003, through December 31, 2004, were included in patient charts. One hundred seventeen violent patient charts were reviewed and compared with 161 non-violent patient charts, randomly chosen from the same time period. Overall use of the Alert assessment form for violent and non-violent patients was 75.7% and 35.4%, respectively. The assessment form was found to have moderate sensitivity (71%) and high specificity (94%). It is reasonably effective in identifying potentially violent or aggressive patients when it is used according to protocol. Efforts to improve the tool are warranted, as is evaluation of its benefit in settings with low prevalence of violence. Also, greater effort must be taken to prevent violence once an aggressive patient has been identified.  相似文献   
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