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   2961篇
  免费   161篇
  国内免费   80篇
耳鼻咽喉   3篇
儿科学   192篇
妇产科学   57篇
基础医学   287篇
口腔科学   73篇
临床医学   340篇
内科学   748篇
皮肤病学   81篇
神经病学   124篇
特种医学   410篇
外科学   336篇
综合类   63篇
一般理论   1篇
预防医学   139篇
眼科学   25篇
药学   132篇
  2篇
肿瘤学   189篇
  2023年   8篇
  2022年   13篇
  2021年   29篇
  2020年   24篇
  2019年   27篇
  2018年   44篇
  2017年   32篇
  2016年   33篇
  2015年   50篇
  2014年   78篇
  2013年   80篇
  2012年   86篇
  2011年   97篇
  2010年   119篇
  2009年   113篇
  2008年   97篇
  2007年   134篇
  2006年   95篇
  2005年   107篇
  2004年   60篇
  2003年   48篇
  2002年   64篇
  2001年   65篇
  2000年   60篇
  1999年   45篇
  1998年   133篇
  1997年   165篇
  1996年   145篇
  1995年   129篇
  1994年   141篇
  1993年   113篇
  1992年   65篇
  1991年   51篇
  1990年   49篇
  1989年   73篇
  1988年   55篇
  1987年   54篇
  1986年   59篇
  1985年   54篇
  1984年   34篇
  1983年   24篇
  1982年   31篇
  1981年   31篇
  1980年   33篇
  1979年   19篇
  1978年   15篇
  1977年   27篇
  1976年   29篇
  1975年   17篇
  1970年   7篇
排序方式: 共有3202条查询结果,搜索用时 250 毫秒
11.
12.
13.
14.
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.  相似文献   
15.
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs.  相似文献   
16.
17.
A crescentic osteotomy of the first metatarsal is unstable during the preliminary healing stage. The authors present a modification in the direction of the cut of the osteotomy. This alteration increases stability at the first metatarsal base.  相似文献   
18.
19.
Current clinical staging, which includes the use of serum tumor markers and imaging techniques, fails to identify the 30–40% of clinical stage I (CS I) nonseminomatous germ cell testicular tumor (NSGCT) patients who have occult metastatic disease. Therefore, there is a real clinical need to evaluate new biological parameters of the primary tumor that might be useful as predictors of occult metastatic disease. This study was undertaken to compare quantitative DNA measurements by flow cytometry and image analysis in CS I NSGCT, and to analyze the relevance of these parameters for predicting occult lymph node involvement. Different blocks of formalin-fixed, paraffin-embedded NSGCTs of 62 CS I patients who underwent retroperitoneal lymph node dissection between 1985 and 1989 were prepared according to the Hedley technique, and analyzed by quantitative cytometry. Thirty-six (58.1%) patients had histologically proven lymph node involvement (pathological stage II), whereas 26 (41.9%) patients (pathological stage I) had neither lymph node metastases according to retroperitoneal lymph node dissection (RPLND) specimens nor tumor recurrence during follow-up. Concordant results were found in 76.5% of the samples by both cytometric techniques. For flow cytometry, the percentages of aneuploid cells in the S- and the G2M+S-phase were the most robust predictive parameters for lymph node involvement, whereas for image analysis the 5c exceeding rate (5cER) had the most predictive significance. Based on the experience obtained in this study, both cytometric techniques provide additional information on tumor aggressiveness that might be useful in therapeutic selection of early stage NSGCT patients for either RPLND or surveillance only.  相似文献   
20.
This study evaluated the short-term effectiveness of a mixed-gender sexual assault prevention program developed for college students. Program participants (n = 177) were compared to non-program participants (n = 132) prior to the program and during a 2-week follow-up period on measures of rape myths, victim empathy, perceived negative consequences and estimated likelihood of committing rape, sexual communication, sexual assault awareness, and risky dating behavior. The prevention program was effective at increasing men’s victim empathy and decreasing their adherence to rape myths but ineffective at changing women’s assault-related knowledge, participation in risky dating behaviors, and sexual communication strategies. Limitations of the study and directions for future research in sexual assault prevention are addressed. Editors’ Strategic Implications: This study provides an important example of the limitations of a single session prevention programming approach (even if it is well designed and executed) in addressing a systemic and pervasive problem like sexual assault on college campuses.  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