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   1065788篇
  免费   64445篇
  国内免费   2324篇
耳鼻咽喉   13558篇
儿科学   35102篇
妇产科学   28978篇
基础医学   142305篇
口腔科学   26161篇
临床医学   86438篇
内科学   212434篇
皮肤病学   19612篇
神经病学   86966篇
特种医学   44929篇
外国民族医学   336篇
外科学   169680篇
综合类   21284篇
一般理论   247篇
预防医学   81744篇
眼科学   22740篇
药学   72933篇
中国医学   2421篇
肿瘤学   64689篇
  2018年   30137篇
  2017年   23845篇
  2016年   26444篇
  2015年   9588篇
  2014年   13115篇
  2013年   19885篇
  2012年   32276篇
  2011年   47370篇
  2010年   34592篇
  2009年   26792篇
  2008年   44781篇
  2007年   48477篇
  2006年   28363篇
  2005年   29474篇
  2004年   29524篇
  2003年   29628篇
  2002年   27400篇
  2001年   41614篇
  2000年   42956篇
  1999年   36427篇
  1998年   10146篇
  1997年   9341篇
  1996年   9153篇
  1995年   8542篇
  1994年   8175篇
  1993年   7638篇
  1992年   28227篇
  1991年   27058篇
  1990年   26527篇
  1989年   25414篇
  1988年   23605篇
  1987年   23209篇
  1986年   22274篇
  1985年   21180篇
  1984年   15825篇
  1983年   13497篇
  1982年   8111篇
  1979年   14595篇
  1978年   10219篇
  1977年   8629篇
  1976年   8155篇
  1975年   8966篇
  1974年   10719篇
  1973年   10185篇
  1972年   9662篇
  1971年   8917篇
  1970年   8603篇
  1969年   8043篇
  1968年   7699篇
  1967年   7086篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
943.
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   
944.
Rapid voltammetric procedures for the determination of water-soluble vitamins C, B1, and B2, fat-soluble vitamin E (α-tocopherol acetate), and quercetin in bioactive food additives have been developed. The systematic error (i.e., correctness) of the proposed procedures was evaluated using certified reference materials and the additive recovery tests, which gave the following limiting metrological characteristics: relative error, 25 %; reproducibility, 28 %; convergence, 22 %. The full analysis time (with sample preparation) did not exceed 2 hours. Voltammetric determinations under optimum conditions can be performed in the automated regime controlled by a computer according to the specially developed software.__________Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 3, pp. 54 – 56, March, 2005.  相似文献   
945.
946.
947.
The effects of some antirheumatics on the formation and retraction of collagen lattices seeded with fibroblasts have been studied. Among the antirheumatics, diclofenac was the most active inhibitor of lattice retraction, then tropesin and to a lesser extent indomethacin. Ibuprofen which is known as a very slight inhibitor of protein synthesis was able to significantly enhance lattice retraction when 10 micrograms/ml (48.5 microM) and 50 micrograms/ml (242 microM) were used.  相似文献   
948.
The diagnosis of hysteria is often incorrect and must be made with great caution. A retrospective study demonstrates that an erroneous diagnosis of hysteria is most likely to be given to females, the psychiatrically ill, patients who embellish and patients who present plausible psychogenic explanations for their illness. Movement disorders and paralysis are the neurologic disorders most frequently mislabeled as hysteria.  相似文献   
949.
This case report illustrates the magnetic resonance imaging (MRI) appearance of a typically asymptomatic renal oncocytoma as a homogeneous mass of medium signal with a stellate central region of decreased signal, representing the central scar. The MRI was correlated with computed tomography (CT), ultrasound (US), and gross pathologic appearance. The appearance of a central scar is not specific for oncocytoma and does not exclude renal cell carcinoma, as illustrated by a second case.  相似文献   
950.
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