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   1684篇
  免费   106篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   94篇
妇产科学   33篇
基础医学   180篇
口腔科学   80篇
临床医学   139篇
内科学   357篇
皮肤病学   33篇
神经病学   121篇
特种医学   428篇
外科学   107篇
综合类   40篇
预防医学   62篇
眼科学   14篇
药学   59篇
  1篇
肿瘤学   37篇
  2023年   13篇
  2022年   8篇
  2021年   16篇
  2020年   18篇
  2019年   24篇
  2018年   22篇
  2017年   25篇
  2016年   24篇
  2015年   31篇
  2014年   44篇
  2013年   55篇
  2012年   51篇
  2011年   57篇
  2010年   50篇
  2009年   62篇
  2008年   41篇
  2007年   51篇
  2006年   39篇
  2005年   39篇
  2004年   29篇
  2003年   31篇
  2002年   20篇
  2001年   28篇
  2000年   16篇
  1999年   17篇
  1998年   80篇
  1997年   81篇
  1996年   80篇
  1995年   65篇
  1994年   40篇
  1993年   61篇
  1992年   6篇
  1991年   14篇
  1990年   25篇
  1989年   57篇
  1988年   41篇
  1987年   50篇
  1986年   54篇
  1985年   67篇
  1984年   38篇
  1983年   29篇
  1982年   29篇
  1981年   32篇
  1980年   38篇
  1979年   9篇
  1978年   18篇
  1977年   23篇
  1976年   21篇
  1975年   20篇
  1914年   1篇
排序方式: 共有1794条查询结果,搜索用时 15 毫秒
991.
992.
993.
Early detection of stress fractures using 99mTc-polyphosphate   总被引:3,自引:0,他引:3  
  相似文献   
994.
Towbin  R; Han  BK; Kaufman  RA; Burke  M 《Radiology》1986,158(3):735-737
Thirteen orbital computed tomographic (CT) scans were obtained in 12 patients with postseptal (orbital) cellulitis. Sinus radiographs, which were also obtained, were not helpful in diagnosis or management. The location and extent of the inflammatory process was accurately demonstrated with axial CT scans in all cases. A protocol using CT in the management of postseptal cellulitis is proposed.  相似文献   
995.
996.
Miller  RA; Lowder  JN; Gralow  J; Meeker  T; Levy  R 《Blood》1987,69(4):1249-1254
The presence of circulating tumor idiotype interferes with the in vivo effectiveness of anti-idiotype antibodies. We developed two assays that permit identification of patients with high levels of serum idiotype without the need for first producing an anti-idiotype antibody. A cell suspension made from the tumor was cultured for seven days with or without phytohemagglutin (PHA) and/or phorbol myristic acetate (PMA). Ig secretion in vitro by patients' tumor cells varied. In 4 patients, no secretion in vitro occurred, 5 patients had low levels, and 5 patients had high levels of Ig secretion. In three patients, Ig secretion occurred only after stimulation with PHA, PMA, or both. Spontaneous or induced immunoglobulin secretion in vitro is related to the levels of tumor idiotype secretion that exist in vivo. Eight patients with serum idiotype levels greater than 100 micrograms/mL (mean 265 micrograms/mL), had a minimum of 1.0 microgram/10(6) cells of idiotype secretion in vitro. Nine patients with serum idiotype levels less than 30 micrograms/mL (mean 3.7 micrograms/mL), had less than or equal to 0.5 microgram/10(6) cells of idiotype secretion in vitro. In another assay, the levels of IgM kappa and IgM lambda in patients' sera were compared with those in normal serum. An imbalance in the relative amounts of IgM kappa and IgM lambda indicated high levels of circulating idiotype in the serum, but this assay was less sensitive than the in vitro secretion assay and limited to IgM-secreting tumors. These assays will be useful for future clinical studies using anti- idiotype antibodies.  相似文献   
997.
998.
999.
Esophagogastric polyps: radiographic and endoscopic findings   总被引:1,自引:0,他引:1  
Radiographic, endoscopic, and pathological findings were correlated in 20 patients with polypoid esophagogastric lesions. In 16 patients, pathological examination showed chronic inflammatory change and epithelial hyperplasia; the polyp was located on the gastric side of the squamocolumnar junction, usually in association with a prominent gastric fold, and probably represented a localized form of gastritis. In the other 4 patients, the lesion was adenocarcinoma. An inflammatory esophagogastric polyp may be differentiated from polypoid carcinoma when adequate radiographs are available and specific diagnostic criteria are followed. Endoscopic biopsy is recommended if the lesion does not fulfill the criteria of an inflammatory esophagogastric polyp.  相似文献   
1000.
Munk  PL; Burhenne  LW; Buffam  FV; Nugent  RA; Lin  DT 《Radiology》1989,173(3):827-830
Dacryocystography has been widely used in the assessment of the nasolacrimal duct system, particularly in patients with epiphora. Our study was undertaken to evaluate image quality and level of patient discomfort during examinations with water-soluble contrast agents (iohexol [Omnipaque 240], iopamidol [Isovue 200 and 300], and 52.7% diatrizoate meglumine and 26.9% iodipamide meglumine [Sinografin]) compared with the iodized oil-based contrast agent Lipiodol. Fifty-five dacryocystograms were obtained from 41 consecutive patients. The procedure was performed first with a water-soluble contrast agent, then repeated with Lipiodol. A distention technique was used with conventional radiography. Patients were asked to evaluate their level of discomfort (none, mild, moderate, severe). The images were evaluated separately by two radiologists, blinded to which water-soluble agent was employed, and the images were graded on a five-point scale. Images obtained with Lipiodol were significantly better than those with other agents (P less than .02), and image quality deteriorated as iodine concentration decreased. Use of Isovue 300 and Sinografin produced significantly more patient discomfort (P less than .03) than the use of other agents. The authors conclude that, in most instances, Lipiodol is the contrast agent of choice with regard to both highest level of patient comfort and greatest conventional radiographic image quality among the agents compared.  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