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   7733篇
  免费   539篇
  国内免费   51篇
耳鼻咽喉   45篇
儿科学   312篇
妇产科学   123篇
基础医学   939篇
口腔科学   89篇
临床医学   742篇
内科学   1628篇
皮肤病学   104篇
神经病学   801篇
特种医学   354篇
外科学   1227篇
综合类   49篇
预防医学   535篇
眼科学   116篇
药学   574篇
中国医学   16篇
肿瘤学   669篇
  2024年   14篇
  2023年   97篇
  2022年   122篇
  2021年   204篇
  2020年   169篇
  2019年   212篇
  2018年   260篇
  2017年   235篇
  2016年   216篇
  2015年   261篇
  2014年   328篇
  2013年   426篇
  2012年   608篇
  2011年   622篇
  2010年   322篇
  2009年   290篇
  2008年   489篇
  2007年   498篇
  2006年   506篇
  2005年   413篇
  2004年   412篇
  2003年   371篇
  2002年   372篇
  2001年   52篇
  2000年   38篇
  1999年   58篇
  1998年   70篇
  1997年   59篇
  1996年   58篇
  1995年   51篇
  1994年   41篇
  1993年   45篇
  1992年   28篇
  1991年   27篇
  1990年   22篇
  1989年   28篇
  1988年   16篇
  1987年   20篇
  1986年   25篇
  1985年   26篇
  1984年   14篇
  1983年   33篇
  1982年   19篇
  1981年   21篇
  1980年   11篇
  1979年   14篇
  1978年   12篇
  1977年   8篇
  1975年   10篇
  1967年   9篇
排序方式: 共有8323条查询结果,搜索用时 15 毫秒
11.

Background  

Previous publications indicate that acupuncture is efficient for the treatment of pelvic girdle pain, PGP, in pregnant women. However, the use of acupuncture for PGP is rare due to insufficient documentation of adverse effects of this treatment in this specific condition. The aim of the present work was to assess adverse effects of acupuncture on the pregnancy, mother, delivery and the fetus/neonate in comparison with women that received stabilising exercises as adjunct to standard treatment or standard treatment alone.  相似文献   
12.
The long half-life and stability of human serum albumin (HSA) make it an attractive candidate for fusion to short-lived therapeutic proteins. Albuferon (Human Genome Sciences [HGS], Inc., Rockville, MD) beta is a novel recombinant protein derived from a gene fusion of interferon-beta (IFN-beta ) and HSA. In vitro, Albuferon beta displays antiviral and antiproliferative activities and triggers the IFN-stimulated response element (ISRE) signal transduction pathway. Array analysis of 5694 independent genes in Daudi-treated cells revealed that Albuferon beta and IFN-beta induce the expression of an identical set of 30 genes, including 9 previously not identified. In rhesus monkeys administered a dose of 50 microg/kg intravenously (i.v.) or subcutaneously (s.c.) or 300 microg/kg s.c., Albuferon beta demonstrated favorable pharmacokinetic properties. Subcutaneous bioavailability was 87%, plasma clearance at 4.7-5.7 ml/h/kg was approximately 140-fold lower than that of IFN-beta, and the terminal half-life was 36-40 h compared with 8 h for IFN-beta. Importantly, Albuferon beta induced sustained increases in serum neopterin levels and 2',5' mRNA expression. At a molar dose equivalent to one-half the dose of IFN-beta, Albuferon beta elicited comparable neopterin responses and significantly higher 2',5'-OAS mRNA levels in rhesus monkeys. The enhanced in vivo pharmacologic properties of IFN-beta when fused to serum albumin suggest a clinical opportunity for improved IFN-beta therapy.  相似文献   
13.
Web-based virtual microscopy in teaching and standardizing Gleason grading   总被引:6,自引:0,他引:6  
Gleason grading forms the basis of prognostic and therapeutic assessment in prostatic carcinoma despite its subjective nature and substantial interobserver variation. The accuracy of Gleason grading can be improved by the use of educational tools such as reference images. However, conventional microscopy images are of limited educational value because it is neither possible to view the sample at different magnifications nor to navigate into different areas of the specimen. This limitation can be overcome by the use of virtual microscopy, which allows viewing entire digitized microscope slides. We created an interactive Web site ( www.webmicroscope.net/gleason ) featuring a comprehensive set of prostatic needle biopsies as virtual slides, which can be viewed with a standard Web browser (Internet Explorer or Netscape). To evaluate the validity of Web-based virtual microscopy for Gleason grading, an experienced uropathologist (TK) scored a series of 62 biopsies from the original glass slides and 6 weeks later from virtual slides on the Web site using an ordinary desktop computer. The intraobserver agreement was excellent, with identical Gleason scores found in 48 of the 62 cases ( kappa = 0.73). The 14 remaining scores differed only by 1 point on the Gleason scale (2-10). The virtual slides were viewed by 2 other uropathologists (PM and HH), with interobserver kappa coefficients ranging from 0.55 to 0.62, which is within the range of previously reported studies using glass slides. The 3 uropathologists' Gleason scores were included as reference scores on the Web site, which now serves as a publicly open platform for self-testing and learning of Gleason grading. We conclude that Web-based virtual microscopy is a promising new tool for teaching and standardizing Gleason grading.  相似文献   
14.
15.
Anti-IgG; antihodies (anti-IgG) of the IgE class were studied in sera from patients with juvenile rheumatoid arthritis (JRA). rheumatoid arthritis (RA) and patients with Felty's syndrome (FS) by use of an indirect immunofluorescence technique. Forty-two percent of 26 patients with JRA had IgE anti-IgG in serum all in low titers. Positive reactions prevailed in patients with multiple joint involvement. Sixty-three percent of 30 patients with RA and 80% of 20 patients with FS had IgE anti-IgG, the titers found in FS patients being significantly higher. In JRA and FS patients the IgE anti-IgG titers were correlated to the titers of anti-IgG of the IgG class, and for FS patients also with the IgM and IgA classes of anti-IgG. In six of 10 patients with RA the synovial fluid samples from both knees contained IgE anti-IgG. In four of these patients the titers of IgE anti-IgG were higher than in the corresponding serum sample, pointing to a local production. After G-200 Sephadex chromatography IgE anti-IgG were demonstrated in the void volume indicating the presence of these autoantibodies in immune complexes. IgE anti-IgG may be involved in the pathogenesis of JRA and RA by eliciting Type I and III reactions.  相似文献   
16.
17.
Grasp stability during object manipulation is achieved by the grip forces applied normal to the grasped surfaces increasing and decreasing in phase with increases and decreases of destabilizing load forces applied tangential to the grasped surfaces. This force coordination requires that the CNS anticipates the grip forces that match the requirements imposed by the self-generated load forces. Here, we use functional MRI (fMRI) to study neural correlates of the grip-load force coordination in a grip-load force task in which six healthy humans attempted to lift an immovable test object held between the tips of the right index finger and thumb. The recorded brain activity was compared with the brain activity obtained in two control tasks in which the same pair of digits generated forces with similar time courses and magnitudes; i.e., a grip force task where the subjects only pinched the object and did not apply load forces, and a load force task, in which the subjects applied vertical forces to the object without generating grip forces. Thus neither the load force task nor the grip force task involved coordinated grip-load forces, but together they involved the same grip force and load force output. We found that the grip-load force task was specifically associated with activation of a section of the right intraparietal cortex, which is the first evidence for involvement of the posterior parietal cortex in the sensorimotor control of coordinated grip and load forces in manipulation. We suggest that this area might represents a node in the network of cortical and subcortical regions that implement anticipatory control of fingertip forces for grasp stability.  相似文献   
18.
19.
20.
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