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   33252篇
  免费   1772篇
  国内免费   307篇
耳鼻咽喉   484篇
儿科学   879篇
妇产科学   1674篇
基础医学   4850篇
口腔科学   489篇
临床医学   2926篇
内科学   6370篇
皮肤病学   1007篇
神经病学   2900篇
特种医学   1397篇
外国民族医学   8篇
外科学   5446篇
综合类   283篇
一般理论   13篇
预防医学   2153篇
眼科学   728篇
药学   2139篇
中国医学   113篇
肿瘤学   1472篇
  2021年   374篇
  2019年   350篇
  2018年   480篇
  2017年   403篇
  2016年   560篇
  2015年   574篇
  2014年   664篇
  2013年   892篇
  2012年   1312篇
  2011年   1372篇
  2010年   816篇
  2009年   738篇
  2008年   1174篇
  2007年   1306篇
  2006年   1390篇
  2005年   1391篇
  2004年   1305篇
  2003年   1247篇
  2002年   1277篇
  2001年   1096篇
  2000年   974篇
  1999年   869篇
  1998年   385篇
  1997年   341篇
  1996年   319篇
  1995年   355篇
  1994年   297篇
  1993年   307篇
  1992年   574篇
  1991年   542篇
  1990年   568篇
  1989年   578篇
  1988年   517篇
  1987年   595篇
  1986年   487篇
  1985年   540篇
  1984年   400篇
  1983年   348篇
  1982年   322篇
  1981年   280篇
  1980年   269篇
  1979年   395篇
  1978年   330篇
  1977年   315篇
  1976年   279篇
  1975年   309篇
  1974年   302篇
  1973年   287篇
  1972年   283篇
  1967年   270篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
21.
Functional evaluation of sacral nerve root integrity. Report of a technique   总被引:4,自引:0,他引:4  
R A Schmidt  E Senn  E A Tanagho 《Urology》1990,35(5):388-392
We report our technique of direct stimulation of the sacral roots governing voiding by which the functional and anatomic integrity of these nerve roots can be assessed in patients with voiding dysfunction. The muscular responses to stimulation of each sacral root are described, as are the landmarks and approach used to achieve stimulation.  相似文献   
22.
23.
24.
Percutaneous nephrolithotomy (PCN) enables the urologist to remove upper urinary tract stones through a percutaneous nephrostomy tract. The principal advantages of PCN are the low morbidity, shortened hospital stay and rapid recovery. Percutaneous puncture failed in 5 (11%) of the first 44 patients with upper tract urolithiasis treated by PCN at Tygerberg Hospital. In 35 patients (80%) PCN cleared the kidney of stones but in 4 patients (9%) all stone fragments were not removed during the procedure. If the puncture and dilatation was successful, then 90% of patients were stone-free after PCN. Complications were minimal except for a diabetic who died of septicaemia. PCN is an alternative to open renal surgery in the management of most upper urinary tract stones. The technique is readily mastered by any urologist experienced in endoscopic surgery.  相似文献   
25.
The Ammann filter test is a subjective method of differentiating functional amblyopia from the organic type. An attempt was made to verify this subjective method by means of visual evoked responses. Good correlation was found with the results described in the literature, obtained by psychophysical examination.  相似文献   
26.
Laparoscopic appendicectomy has been the subject of several encouraging reports, but has not as yet gained widespread acceptance. We present a series of 159 consecutive laparoscopic appendicectomies performed, over a 4 yr period, in both adults and children. We find the procedure as safe as its open counterpart, with patients fit to leave hospital within the same time period. Perforated appendices were amenable to this procedure, and the location of the appendix did not alter the outcome. Children responded as well as adults post-operatively. Obesity may be an indication for this form of treatment. Removal of displaced faecoliths associated with perforated appendicitis is a difficult technical problem in less than 5 per cent of patients.  相似文献   
27.
The heterogeneity of cells capable of metastasation has proved to be the greatest obstacle to successful treatment or to prevention of metastatic diseases. This variety appears to be attributable to processes of selection. Cytobiological investigations which are helpful in casting some light at selective mechanisms of metastasation may, perhaps, make substantive contributions to cancer therapy.  相似文献   
28.
Cultured bovine corneal endothelial cells were labeled with either [35S]sulfate or a combination of [3H]glucosamine and [35S]methionine. The medium proteoheparan sulfate (HS-PG) and cell-associated HS-PG were isolated and identified as heparan sulfate-containing proteoglycans by the susceptibility of their glycosaminoglycan component to specific enzymatic and chemical degradation. The native medium HS-PG has an apparent Mr of about 300,000 and an Mr of its protein core of 64,000, while the native cell-associated HS-PG had a lower molecular weight (approx. 100,000) and an Mr of its protein core of 33,000. The protein core of both HS-PG types consisted of a single polypeptide chain. After beta-elimination reaction of the native HS-PGs the resulting heparan sulfate side chains of medium HS-PG had an Mr of about 60,000, and those of cell-associated HS-PG an Mr of about 30,000. The different molecular parameters of medium HS-PG and cell-associated HS-PG refer to different functional roles. The medium HS-PG secreted by the endothelial cells is regarded as a metabolic precursor of the Descemet's membrane, while the cell-associated HS-PG might represent a cell membrane-integrated proteoglycan.  相似文献   
29.
Iatrogenic damage to the orbital fascial system during strabismus surgery may lead to adherences with resulting problems of motility. To prevent new adherences in revisional surgery, several materials were tried, with varying degrees of success. The authors tested Polyglactin 910, popular as a suture material in strabismus surgery, in the form of a net. The material is hydrolytically soluble. Since the tissue response is finished before dissolution of the implant, it seemed that Polyglactin would be a suitable barrier to the formation of adhesions in Tenon's capsule. The implant was applied in 11 patients, some of whom had already undergone several strabismus operations and had adhesions at the surgical site. In one case the implant was used in a primary procedure. In one patient revisional surgery was needed four weeks after surgery because of overeffect, and this provided an opportunity to investigate the implanted area histologically.  相似文献   
30.
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