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   17871篇
  免费   1347篇
  国内免费   45篇
耳鼻咽喉   148篇
儿科学   665篇
妇产科学   365篇
基础医学   2664篇
口腔科学   290篇
临床医学   1823篇
内科学   4042篇
皮肤病学   253篇
神经病学   1960篇
特种医学   584篇
外国民族医学   3篇
外科学   2286篇
综合类   201篇
一般理论   7篇
预防医学   1148篇
眼科学   657篇
药学   838篇
中国医学   14篇
肿瘤学   1315篇
  2021年   203篇
  2019年   238篇
  2018年   279篇
  2017年   226篇
  2016年   264篇
  2015年   278篇
  2014年   354篇
  2013年   521篇
  2012年   776篇
  2011年   827篇
  2010年   475篇
  2009年   447篇
  2008年   666篇
  2007年   806篇
  2006年   783篇
  2005年   740篇
  2004年   759篇
  2003年   661篇
  2002年   706篇
  2001年   607篇
  2000年   596篇
  1999年   483篇
  1998年   199篇
  1997年   175篇
  1996年   155篇
  1995年   173篇
  1994年   150篇
  1993年   142篇
  1992年   440篇
  1991年   411篇
  1990年   410篇
  1989年   354篇
  1988年   348篇
  1987年   337篇
  1986年   348篇
  1985年   311篇
  1984年   266篇
  1983年   227篇
  1982年   161篇
  1981年   158篇
  1980年   136篇
  1979年   219篇
  1978年   187篇
  1977年   136篇
  1976年   139篇
  1975年   140篇
  1974年   166篇
  1973年   163篇
  1972年   133篇
  1971年   131篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
In two patients with apparent PTO, as diagnosed by HSG and laparoscopy, tubal patency was restored by hysteroscopic cannulation of the tubal ostia, followed by direct lavage. Tubal resection and reanastomosis/reimplantation may not be necessary for all patients with apparent PTO.  相似文献   
53.
This study is comprised of 71 patients with inversion injuries. The purpose of this article is to present a logical and orderly approach in evaluating these injuries. A comprehensive review of the literature concerning diagnostic techniques and mechanisms of injury related to inversion ankle trauma is presented. Inversion ankle injuries are frequently misdiagnosed as simple sprains when frequently there are other pathologies present. The standard approach of evaluating inversion ankle injuries is often inadequate.  相似文献   
54.
78 geriatric patients predominantly suffering from cardiocerebrovascular diseases (stroke, heart insufficiency) and lesions respectively operations of the locomotion system (fractures, arthroses) were admitted in 1987 from acute hospitals for after-treatment (short-term care). 35 (= 45%) of them (average age 80 (61-92) could be discharged after 63.5 days on average, 11 died from intercurrent complications, 9 remained for long-term care as inrehabilitable. Besides other concomiting troubles mainly cardiac and circulation affections were present in the majority of patients. Their identification (a. o. by means of ultrasonic methods) and therapy also means a secondary prevention of cerebral as well as of fall and injuries inducing risk factors. The results confirm the principal rehabilitation chance of multimorbid geriatric patients by use of the diagnostic and therapeutic special potential of geriatrics.  相似文献   
55.
Epidemiological studies have indirectly linked compounds ofchromium, nickel and arsenic to human carcinogenesis. However,there is no evidence that metal compounds can transform humancells to the tumorigenic phenotype in culture. We show herethat exposure to 36 µM NiS04 for 48–96 h resultsin transformation of an immortal, non-tumorigenic, osteoblast-likecell line, HOS TE85, to the tumorigenic phenotype. Continuouspassaging following treatment leads to the formation of a fewdense foci. The cells isolated and expanded from the foci aremorphologically transformed, and form anchorage-independentcolonies of the size and abundance comparable to that formedby Kirsten murine sarcoma virus transformed HOS TE85 cells.The transformed cells from tumors in nude mice, have enhancedlevels of plasminogen activators and have lost the ability toform model bone matrix on extended culture in the presence ofascorbic acid and ß-glycerophosphate. A number ofcell lines have been established from nude mouse tumors. Cytogeneticanalysis reveals 16 marker chromosomes and an aberrant chromosome16. This is the first report of the transformation of a humancell line to tumorigenic phenotype by a metal carcinogen.  相似文献   
56.
Perforation of esophageal malignancy secondary to instrumentation is an uncommon but catastrophic complication. Esophageal perforation at the site of an obstructing esophageal malignancy precludes simple operative repair and mandates esophageal resection with reestablishment of gastro-intestinal tract continuity. In the past the standard surgical approach has involved transthoracic esophageal resection via thoracotomy. We have successfully treated four patients with perforated esophageal neoplasms by transhiatal esophagectomy and cervical esophagogastrostomy, thus avoiding thoracotomy in high-risk patients. We consider transhiatal esophagectomy an advantageous alternative in the management of selected cases of instrumental esophageal perforation adjacent to an esophageal malignancy.  相似文献   
57.
58.
A prospective study of 35 patients in the neonatal intensive care unit was conducted to examine the safety and feasibility of percutaneous Silastic central venous catheters for the provision of prolonged parenteral alimentation. Particular attention was directed to the possibility of maintaining these lines through intercurrent episodes of infection. Catheters were placed in 34 infants (97%). At the time of insertion, 21 patients (62%) weighed less than 1000 gm and 13 patients (38%) weighed less than 750 gm. The average duration of catheterization was 32.0 +/- 18.2 (SD) days; 19 patients (56%) had lines in place for more than 30 days. Mechanical difficulties complicated the course of five patients (15%). Four cases of bacteremia were identified; this represents 3.7 infections/1000 days of catheter use. All infections were caused by methicillin-resistant staphylococci. Two patients required catheter removal to clear their infection, but in two of the four bacteremic patients, the infection was cleared and the line was sterilized by the administration of antibiotic therapy through the central catheter. We conclude that Silastic central venous catheters can be used safely to deliver intravenous nutrition to extremely small preterm infants over a prolonged period of time, and in carefully selected patients, successful treatment of complicating infections may be achieved without catheter removal.  相似文献   
59.
In the past few years there have been numerous publications which have stressed the value of the dexamethasone suppression test (DST) as a diagnostic marker of endogenous depression. Our own studies in 333 psychiatric inpatients and 121 healthy subjects did not reveal a differential diagnostic use for the DST. This result is in good agreement with other results in the literature. Our data demonstrate that intervening variables such as severity of illness, weight loss, sleep disturbances, situational stress, drug and alcohol withdrawal, and the pharmacokinetics of dexamethasone have an important influence on DST results, regardless of the diagnostic classification.  相似文献   
60.
The results with two new enucleation prothesis made of Bioverit are presented. After unilateral enucleation 14 rabbits received bioreactive, 14 rabbits biocompatible and 9 rabbits nylon prostheses. Implantation periods: 1-13 months. The tissue surrounding of the prostheses was studied histologically, the ceramic electron microscopically. Of 28 ceramic prostheses, 26 were adapted very well. Bioverit ist excellently suited as orbital prosthetic material, even half-open implants are possible.  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