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   202673篇
  免费   1668篇
  国内免费   101篇
耳鼻咽喉   1929篇
儿科学   7553篇
妇产科学   5178篇
基础医学   20377篇
口腔科学   2640篇
临床医学   13462篇
内科学   35203篇
皮肤病学   1543篇
神经病学   18972篇
特种医学   9333篇
外科学   31601篇
综合类   2444篇
一般理论   2篇
预防医学   19979篇
眼科学   3866篇
药学   12650篇
中国医学   669篇
肿瘤学   17041篇
  2021年   224篇
  2020年   177篇
  2019年   323篇
  2018年   22450篇
  2017年   17717篇
  2016年   19945篇
  2015年   1398篇
  2014年   1525篇
  2013年   1878篇
  2012年   8125篇
  2011年   22261篇
  2010年   19571篇
  2009年   11885篇
  2008年   20192篇
  2007年   22565篇
  2006年   1626篇
  2005年   3184篇
  2004年   4459篇
  2003年   5397篇
  2002年   3396篇
  2001年   1117篇
  2000年   1230篇
  1999年   879篇
  1998年   410篇
  1997年   286篇
  1992年   453篇
  1991年   462篇
  1990年   525篇
  1989年   525篇
  1988年   544篇
  1987年   507篇
  1986年   497篇
  1985年   484篇
  1984年   381篇
  1983年   299篇
  1979年   556篇
  1978年   335篇
  1977年   280篇
  1976年   273篇
  1975年   370篇
  1974年   541篇
  1973年   521篇
  1972年   433篇
  1971年   414篇
  1970年   417篇
  1969年   450篇
  1968年   390篇
  1967年   292篇
  1966年   307篇
  1965年   192篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
The effect of ferritins from horse (FH) and bovine (FB) spleen and murine liver (FM) on the survival rate of CFW mice lethally infected with Escherichia coli (strain 8440-78 K 80/B) was evaluated. Ferritins given intravenously 24 h before intravenous inoculation of bacteria, protected mice most effectively from death due to infection. The effect was dose dependent. At 500 micrograms of ferritin per mouse, the maximum survival rates were 86% (FH), 81% (FM) and 79% (FB), while only 5% of the control mice survived up to the 30th day. The survival rates of animals injected with bovine serum albumin (BSA) and heat-inactivated FB were 8 and 25%, respectively. Intraperitoneal injection of FB was as effective as intravenous in enhancing the resistance of mice against bacteria. These data provide evidence for the beneficial role of tissue ferritins in nonspecific antibacterial resistance.  相似文献   
82.
83.

Background  

The telomeric region of mouse chromosome 12 has previously shown frequent allelic loss in murine lymphoma. The Bcl11b gene has been identified and suggested as a candidate tumor suppressor gene within this region. In this study, we aimed to elucidate whether Bcl11b is mutated in lymphomas with allelic loss, and whether the mutations we detected conferred any effect on cell proliferation and apoptosis.  相似文献   
84.
85.
Abstract 10 embalmed cadaver forearms and wrists were dissected to determine the anatomical course of the superficial branch of the radial nerve in the distal forearm. The superficial radial nerve bifurcated in two branches at a mean of 54,7 mm proximal to the radial styloid. From the styloid process of the radius, the mean distance to the closest dorsal branch of the superficial radial nerve was 3,5 mm and the mean distance to the closest volar branch was 9,8 mm. The mean distance between the closest branch of the superficial radial nerve and Lister?s tubercle was 16,4 mm. The crossing point between the nerve and the cephalic vein was located at a mean of 54,3 mm proximal to the styloid process. At the level of styloid process the mean distance between the closest dorsal branch of the superficial radial nerve and the first dorsal compartment was 15,2 mm and between the closest volar branch and the first dorsal compartment 4,4 mm. Detailed knowledge of anatomic characteristics of the superficial branch of the radial nerve may help prevent injury during operations and treat traumatic lesions of the nerve. Because of great variations in the course of the superficial radial nerve we could not define an absolute safe zone for surgical procedures on the distal forearm. Iatrogenic lesions of the superficial radial nerve are described complications of percutaneous procedures. Therefore open surgical approaches are recommended. Daniela Klitscher and Lars Peter Müller contributed equally to this work.  相似文献   
86.
87.
Benign schwannoma of the pancreas   总被引:2,自引:0,他引:2  
Reported cases of intrapancreatic schwannomas have recently increased in the literature. However, none of these cases were diagnosed clearly as schwannoma preoperatively. We herein describe the clinicopathologic findings of a solitary benign schwannoma occurring in the head of the pancreas. Additionally, the differential diagnosis versus other cystic- and solid-appearing pancreatic masses is briefly discussed.  相似文献   
88.
Genetic studies on spontaneous mouse mutants with hearing defects have provided important insights into the function of genes expressed in inner ear hair cells. Here we report on our genetic analyses of the deaf mutants varitint-waddler (Va) and jerker (Espnje). A high-resolution genetic map localizes VaJ to a 0.14 ± 0.08 cM region between D3Mit85 and D3Mit259 on distal chromosome 3. By comparative mapping, the human ortholog resides at 1p22.3 between markers D1S3449 and D1S2252. To study the effect of different genetic backgrounds on the hearing phenotype, Espnje and VaJ were crossed to various inbred strains. Auditory-evoked brainstem response tests on F2 progeny demonstrate that expression, inheritance, and penetrance of the hearing phenotype are solely controlled by the mutant allele. To test for a genetic interaction between Espnje and Cdh23v, auditory function was analyzed in double heterozygotes; no significant increases of thresholds of sound pressure levels were observed. The results establish the framework for cloning the Va gene and provide valuable insights into the genetics of deafness mutations in the mouse.  相似文献   
89.
Abstract Surgical treatment of proximal humeral fractures still remains a challenge. This is primarily due to the fact that sufficient implant fixation in humeral head fractures is often not achieved due to substantial bone tissue loss with increasing age. In the last few years the locking plates and locking nails have been introduced into clinical practice with varying results. The biomechanical studies have focused on locking plate osteosynthesis as well. The following paper focuses on bone quality, biomechanical studies and biology of proper osteosynthesis and reviews the most recent literature.  相似文献   
90.
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