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   4307篇
  免费   281篇
  国内免费   42篇
耳鼻咽喉   62篇
儿科学   136篇
妇产科学   100篇
基础医学   369篇
口腔科学   56篇
临床医学   432篇
内科学   904篇
皮肤病学   142篇
神经病学   300篇
特种医学   808篇
外科学   501篇
综合类   54篇
一般理论   2篇
预防医学   193篇
眼科学   241篇
药学   119篇
中国医学   5篇
肿瘤学   206篇
  2021年   29篇
  2019年   40篇
  2018年   52篇
  2017年   43篇
  2016年   42篇
  2015年   53篇
  2014年   65篇
  2013年   145篇
  2012年   134篇
  2011年   126篇
  2010年   103篇
  2009年   111篇
  2008年   130篇
  2007年   136篇
  2006年   159篇
  2005年   182篇
  2004年   159篇
  2003年   134篇
  2002年   145篇
  2001年   130篇
  2000年   124篇
  1999年   128篇
  1998年   134篇
  1997年   109篇
  1996年   98篇
  1995年   90篇
  1994年   89篇
  1993年   73篇
  1992年   82篇
  1991年   100篇
  1990年   87篇
  1989年   120篇
  1988年   111篇
  1987年   139篇
  1986年   109篇
  1985年   90篇
  1984年   67篇
  1983年   45篇
  1982年   43篇
  1981年   39篇
  1979年   61篇
  1978年   33篇
  1977年   45篇
  1976年   51篇
  1975年   45篇
  1974年   36篇
  1973年   41篇
  1972年   31篇
  1971年   34篇
  1970年   33篇
排序方式: 共有4630条查询结果,搜索用时 15 毫秒
31.
32.
33.
Rupture of an intra-aortic balloon counterpulsator (IABCP) demands immediate removal. We report a case of thrombus formation within a Datascope IABCP secondary to IABCP rupture, necessitating surgical exploration for removal. There is a disturbing pattern of balloon ruptures with this type of IABCP.  相似文献   
34.
A series of O-acyl derivatives of 6-hydroxybenzothiazole-2-sulfonamide (4, L-643,799) was prepared and the potential utility of each series member as a topically active inhibitor of ocular carbonic anhydrase was determined. In vitro studies showed these esters to be substrates for ocular esterases which liberate 4 during corneal translocation. The most interesting series member, 2-sulfamoyl-6-benzothiazolyl 2,2-dimethylpropionate (22, L-645,151), acting as a prodrug form of 4, was found to enhance delivery through the isolated albino rabbit cornea by 40-fold when compared to the parent phenol 4. Studies in rabbits revealed that 22 is a potent topically active ocular hypotensive carbonic anhydrase inhibitor.  相似文献   
35.
The authors investigated the effect of liposome encapsulation on the pharmacokinetics of gentamicin after intravitreal injection in albino rabbits, using immunofluorescent assay. Gentamicin was encapsulated into liposomes of phosphatidylcholine, phosphatidic acid, and alpha-tocopherol. The final liposomal suspension contained gentamicin, 10 mg/ml, 95% encapsulated. One eye of each rabbit received an intravitreal injection (100 mg gentamicin per 0.1 ml) of either liposome-encapsulated gentamicin (LEG) or gentamicin in phosphate-buffered saline (Gs). Equilibrium dialysis separated free from encapsulated drug in vitreous samples. The peak free drug concentration was significantly less (P less than .01, unpaired t-test) with LEG than with Gs. Concentrations of free and total gentamicin were significantly greater (P less than .05) with LEG than with Gs at 24, 72, 120, and 192 hr. LEG gave a twofold increase in area under the drug concentration time curve for total drug, and a 1.5-fold increase for free drug when compared to Gs.  相似文献   
36.
37.
38.
A new computed tomographic and sonographic appearance of renal metastatic melanoma is described. Bilateral cystic masses with thick walls, many with mural nodules, were noted. Sonography also demonstrated complex echopenic masses with irregularly thickened walls and mural nodules.  相似文献   
39.
McLellan  GL; Scalapino  MC 《Radiology》1988,169(1):264-265
A modified technique for catheterization of the pulmonary artery was developed. It involves the passage of a tapered, movable-core, J-tipped guide wire across the right ventricle into the pulmonary artery followed by the advancement of a straightened Grollman pigtail catheter. The technique was successful in 34 of 34 pulmonary artery catheterizations. The method avoids prolonged catheter manipulation within the right ventricle. In addition, since the catheter does not cross the tricuspid valve until the guide wire has been advanced, the occasional complication of the pigtail "hooking" on a tricuspid valve leaflet or chordae tendineae during catheter withdrawal and manipulation is prevented.  相似文献   
40.
Although well defined pathologically, alveolar cell carcinoma can be difficult to diagnose because of its many clinical presentations. In a retrospective study of 45 cases, we reviewed the radiologic, pathologic, and clinical features of this neoplasm. Forty-one patients had a single peripheral mass that measured between 8 mm and 7 cm. Three patients had multiple nodules, and one had diffuse involvement of the right lung. Other prominent radiologic features included air bronchograms in eight cases, a "tail sign" in ten cases, and universal absence of calcifications. Pathologic examination showed an associated scar in 12 patients. There was a relatively high frequency (16%) of metachronous malignancies, including two osteosarcomas, three basal cell carcinomas, and one case each of chronic lymphocytic leukemia and thymoma. All but one of the associated tumors were diagnosed six months to two years before the diagnosis of alveolar cell carcinoma.  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