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   819篇
  免费   78篇
  国内免费   39篇
耳鼻咽喉   10篇
儿科学   40篇
妇产科学   55篇
基础医学   78篇
口腔科学   8篇
临床医学   100篇
内科学   224篇
皮肤病学   8篇
神经病学   19篇
特种医学   121篇
外科学   92篇
综合类   28篇
预防医学   19篇
眼科学   16篇
药学   79篇
中国医学   6篇
肿瘤学   33篇
  2023年   1篇
  2021年   14篇
  2020年   10篇
  2019年   30篇
  2018年   25篇
  2017年   27篇
  2016年   22篇
  2015年   33篇
  2014年   39篇
  2013年   55篇
  2012年   52篇
  2011年   38篇
  2010年   48篇
  2009年   37篇
  2008年   35篇
  2007年   66篇
  2006年   32篇
  2005年   22篇
  2004年   31篇
  2003年   18篇
  2002年   24篇
  2001年   15篇
  2000年   14篇
  1999年   6篇
  1998年   21篇
  1997年   25篇
  1996年   28篇
  1995年   12篇
  1994年   22篇
  1993年   13篇
  1992年   13篇
  1991年   8篇
  1990年   10篇
  1989年   13篇
  1988年   8篇
  1987年   6篇
  1986年   10篇
  1985年   11篇
  1984年   7篇
  1983年   7篇
  1982年   7篇
  1981年   8篇
  1980年   2篇
  1978年   1篇
  1977年   4篇
  1976年   1篇
  1975年   2篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
排序方式: 共有936条查询结果,搜索用时 15 毫秒
1.
2.
3.
Beckmann  CF; Roth  RA; Luedke  MD 《Radiology》1986,159(3):643-645
In 44 patients with one or more calculi in the upper two-thirds of the ureter, single-stage percutaneous nephrolithotomy was performed through a middle or upper calyceal nephrostomy after cystoscopic placement of an occlusion balloon catheter distal to the calculus; in 42, the procedure was successful. The occlusion balloon catheter permitted retrograde opacification of all systems for enhanced renal puncture. In the last 30 patients an attempt was made either to push the calculus upward mechanically or to flush it upward into the renal pelvis with carbon dioxide or dilute contrast material. This was successful in 24 of these patients. Prior overnight occlusion of the ureter by means of ureteral dilatation further facilitates dislodgment of the calculus, which was successful in 12 of 13 patients.  相似文献   
4.
5.
6.
7.
Although computed tomography (CT) and magnetic resonance imaging scans often appear normal after mild head trauma, many patients experience attentional or other cognitive disturbances that are difficult to quantify by neuropsychological testing in the absence of a premorbid profile. Within 2 days of mild head trauma, 14 patients with normal-appearing brain CTs were studied with single-photon emission computed tomography (SPECT). They were compared to 15 normal control subjects and to 12 patients with mild human immunodeficiency virus (HlV) encephalopathy. Ten of 14 head trauma patients were separated from the normal control subjects by both independent readers, blinded to the clinical diagnosis. None of the SPECT results from normal control subjects were ‘read’ as trauma. Trauma could not be differentiated from HlV encephalopathy. The observed percentage agreement between raters was 0.83 (K = 0.72). SPECT is more sensitive than CT in detecting brain injury after mild head trauma.  相似文献   
8.
9.
By utilizing a strain of cultivable simian rotavirus (SA-11) as an immunizing antigen, we prepared 4 clones of mouse-mouse hybridoma, namely C127, C139, C172, and C214 which secreted monoclonal antibodies against the immunogen itself, SA-11 and also against other group A strains such as Wa and S2. Western blot analyses revealed that all of these antibodies are directed against VP6, a 42 kDa major inner capsid protein of group A rotavirus. Competitive experiments suggested that C127, C172 and C214 recognized three distinct epitopes on VP6, while C139 appeared to react with an epitope at or near the same epitope recognized by C172. We developed a two-step ELISA with excellent sensitivity and specificity for rotavirus detection by utilizing C127 and/or C214 as a capture antibody and rabbit anti-rotavirus conjugated with horseradish peroxidase as a probe. Also, when both monoclonal C127 capture antibody and polyclonal rabbit anti-rotavirus-HRP were incubated with rotavirus simultaneously in a one-step assay, equivalent sensitivity and specificity were observed. The data show that these generated anti-rotavirus antibodies can be utilized effectively as reagents for the detection of human rotaviruses in stool specimens.  相似文献   
10.
Elevated blood pressure is an important risk factor for renal-, cerebro- and cardiovascular diseases. We used an efficient discordant sib-pair ascertainment scheme to investigate the impact of the distal end of the long arm of human chromosome 5 (chromosomal region 5q31.1-qter) containing genes for the alpha1B and beta2 adrenergic receptors and the dopamine receptor type 1A on variation of systolic blood pressure in young Caucasians. We measured eight highly polymorphic markers spanning this positional candidate gene-rich region in 427 individuals from 55 three-generation pedigrees containing 69 discordant sibling pairs, and calculated multipoint identity by descent (MIBD) probabilities. The results of genetic linkage and association tests indicate that the region between markers D5S2093 and D5S462 is significantly linked to one or more polymorphic genes influencing interindividual variation in systolic blood pressure levels. Since the alpha1B adrenergic receptor and dopamine receptor type 1A genes are located close to these markers, these data suggest that genetic variation in one or both of these G protein-coupled receptors, which participate in the control of vascular tone, plays an important role in influencing interindividual variation in systolic blood pressure levels.   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