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   136311篇
  免费   9445篇
  国内免费   659篇
耳鼻咽喉   1652篇
儿科学   3443篇
妇产科学   2449篇
基础医学   17401篇
口腔科学   2906篇
临床医学   13332篇
内科学   28056篇
皮肤病学   1766篇
神经病学   11958篇
特种医学   5450篇
外科学   21860篇
综合类   1975篇
现状与发展   1篇
一般理论   173篇
预防医学   12409篇
眼科学   2918篇
药学   9630篇
  2篇
中国医学   179篇
肿瘤学   8855篇
  2023年   672篇
  2022年   1050篇
  2021年   2575篇
  2020年   1467篇
  2019年   2397篇
  2018年   2924篇
  2017年   2112篇
  2016年   2232篇
  2015年   2720篇
  2014年   4025篇
  2013年   6064篇
  2012年   8874篇
  2011年   9445篇
  2010年   5272篇
  2009年   4824篇
  2008年   8401篇
  2007年   9006篇
  2006年   8583篇
  2005年   8725篇
  2004年   8381篇
  2003年   7872篇
  2002年   7684篇
  2001年   1282篇
  2000年   1053篇
  1999年   1402篇
  1998年   1654篇
  1997年   1338篇
  1996年   1280篇
  1995年   1233篇
  1994年   1044篇
  1993年   1022篇
  1992年   843篇
  1991年   863篇
  1990年   757篇
  1989年   742篇
  1988年   758篇
  1987年   744篇
  1986年   762篇
  1985年   848篇
  1984年   910篇
  1983年   871篇
  1982年   1135篇
  1981年   1162篇
  1980年   965篇
  1979年   631篇
  1978年   672篇
  1977年   599篇
  1976年   519篇
  1975年   471篇
  1974年   471篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
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   
73.
74.
75.

Background  

Bortezomib, a proteasome-specific inhibitor, has emerged as a promising cancer therapeutic agent. However, development of resistance to bortezomib may pose a challenge to effective anticancer therapy. Therefore, characterization of cellular mechanisms involved in bortezomib resistance and development of effective strategies to overcome this resistance represent important steps in the advancement of bortezomib-mediated cancer therapy.  相似文献   
76.
77.
78.
79.
80.
Several case reports have implicated Ginkgo biloba in clinically adverse bleeding disorders. Ginkgo biloba has been reported to increase pain-free walking distance among patients with peripheral artery disease (PAD). Standard PAD therapy includes 325 mg/day aspirin. The objective of this study was to examine potential adverse effects of concomitant aspirin and Ginkgo biloba on platelet function. Ginkgo biloba (EGb 761, 300 mg/day) was compared with placebo for effects on measures of platelet aggregation among adults consuming 325 mg/day aspirin in a randomized, double-blind, placebo-controlled, parallel design trial of 4-week duration. Participants were adults, age 69 +/- 10 years, with PAD or risk factors for cardiovascular disease. Outcome measures included platelet function analysis (PFA-100 analyzer) using ADP as an agonist (n = 26 placebo; n = 29 ginkgo), and platelet aggregation using ADP, epinephrine, collagen and ristocetin as agonists (n = 21 placebo; n = 23 ginkgo). Participants kept daily logs of bleeding or bruising episodes. There were no clinically or statistically significant differences between treatment groups for any agonists, for either PFA-100 analysis or platelet aggregation. Reports of bleeding or bruising were infrequent and similar for both study groups. In conclusion, in older adults with PAD or cardiovascular disease risk, a relatively high dose of Ginkgo biloba combined with 325 mg/day daily aspirin did not have a clinically or statistically detectable impact on indices of coagulation examined over 4 weeks, compared with the effect of aspirin alone. No adverse bleeding events were observed, although the trial was limited to a small sample size.  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