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   1143篇
  免费   91篇
  国内免费   16篇
耳鼻咽喉   4篇
儿科学   74篇
妇产科学   17篇
基础医学   147篇
口腔科学   13篇
临床医学   121篇
内科学   240篇
皮肤病学   25篇
神经病学   120篇
特种医学   151篇
外科学   111篇
综合类   43篇
一般理论   1篇
预防医学   79篇
眼科学   8篇
药学   51篇
肿瘤学   45篇
  2021年   19篇
  2019年   12篇
  2018年   8篇
  2017年   8篇
  2016年   12篇
  2015年   27篇
  2014年   17篇
  2013年   31篇
  2012年   21篇
  2011年   56篇
  2010年   34篇
  2009年   50篇
  2008年   43篇
  2007年   62篇
  2006年   47篇
  2005年   57篇
  2004年   48篇
  2003年   49篇
  2002年   35篇
  2001年   35篇
  2000年   34篇
  1999年   23篇
  1998年   27篇
  1997年   42篇
  1996年   31篇
  1995年   32篇
  1994年   22篇
  1993年   8篇
  1992年   25篇
  1991年   11篇
  1990年   23篇
  1989年   26篇
  1988年   17篇
  1987年   27篇
  1986年   24篇
  1985年   18篇
  1984年   15篇
  1983年   17篇
  1982年   12篇
  1981年   15篇
  1980年   15篇
  1978年   9篇
  1977年   11篇
  1976年   11篇
  1975年   9篇
  1974年   8篇
  1973年   6篇
  1968年   7篇
  1967年   7篇
  1966年   9篇
排序方式: 共有1250条查询结果,搜索用时 15 毫秒
1.
2.
3.
Anogenital trauma in sexually abused children   总被引:3,自引:0,他引:3  
M A Finkel 《Pediatrics》1989,84(2):317-322
Physical findings, when identified, lend powerful support to the validation and prosecution in child sexual abuse cases. Because of the frequent delay between the alleged molestation, disclosure, and examination, there is a need for a systematic method of identifying and interpreting the residual of anal and genital trauma after the acute signs have disappeared. The case findings of seven children who experienced acute genital and anal trauma and were observed until their injuries healed are reported.  相似文献   
4.
Abstrakt 1. Nimmt ein Patient einen ihm von seinem (Zahn-)Arzt einger?umten Exklusiv-Termin nicht wahr, obwohl er auf dessen Eigenschaft ausdrücklich hingewiesen wurde, so hat er dem (Zahn-)Arzt den Behandlungsausfall abzüglich eines angemessenen Eigenanteils des (Zahn-)Arztes zu ersetzen. 2. Die Ersatzpflicht tritt auch dann ein, wenn der Patient den Termin nicht in der in dem Behandlungsvertrag vorgesehenen Frist absagt. Eine hierfür seitens des (Zahn-)Arztes bestimmte Frist von zwei Tagen vor Behandlungsbeginn stellt sich für den Patienten grunds?tzlich auch nicht als unangemessene Benachteiligung i.S. des § 307 BGB dar. 3. Ein Anspruch des Arztes entf?llt auch bei nur mündlicher Vereinbarung nicht unter dem Gesichtspunkt des § 4 Abs. 5b BMV-Z, denn diese Vorschrift ist teleologisch dahin zu reduzieren, dass nur zahn?rztliche Honoraransprüche aus erfolgten Behandlungen schriftlich vereinbart werden müssen. Soweit es jedoch um einen vertraglichen Anspruch wegen einer Leistungsst?rung geht, vermag das Schriftformerfordernis des § 4 Abs. 5b BMV-Z grunds?tzlich nicht einzugreifen. (Leits?tze des Bearbeiters)  相似文献   
5.
6.
7.
8.
Early during rat thymus ontogeny, an important proportion of thymocytes expresses IL-2R and contains IL-2 mRNA. To investigate the role of the IL-2-IL-2R complex in rat T cell maturation, we supplied either recombinant rat IL-2 or blocking anti-CD25 mAb to rat fetal thymus organ cultures (FTOC) under several experimental conditions. The IL-2 treatment initially stimulated the growth of thymocytes and, as a result, induced T cell differentiation, but the continuous addition of IL-2 to rat FTOC, as well as the anti-CD25 administration, resulted in cell number decrease and inhibition of thymocyte maturation. These results indicate that immature rat thymocytes bear functional high- affinity IL-2R and that IL-2 promotes T cell differentiation as a consequence of its capacity to stimulate cell proliferation. Modifications in TCR alpha beta repertoire and increased numbers of NKR- P1+ cells, largely NK cells, were also observed in IL-2-treated FTOC. Furthermore, IL-2-responsiveness of different thymocyte subsets changed throughout thymic ontogeny. Immature CD4-CD8-cells responded to IL-2 in two stages, early in thymus development and around birth, in correlation with the maturation of two distinct waves of thymic cell progenitors. Mature CD8+ thymocytes maximally responded to IL-2 around birth, supporting a role for IL-2 in the increased proliferation of mature thymocytes observed in vivo in the perinatal period. Taken together, these findings support a role for IL-2 in rat T cell development.   相似文献   
9.
A computer model based on visual cortex has been constructed to analyze how the operations of multiple, functionally segregated cortical areas can be coordinated and integrated to yield a unified perceptual response. We propose that cortical integration arises through the process of reentry--the ongoing, parallel, recursive signaling between separate maps along ordered anatomical connections. To test the efficacy of this reentrant cortical integration (RCI) model, we have carried out detailed computer simulations of 3 interconnected cortical areas in the striate and extrastriate cortex of the macaque. The simulated networks contained a total of over 222,000 units and 8.5 million connections. The 3 modeled areas, called VOR, VOC, and VMO, incorporate major anatomical and physiological properties of cortical areas V1, V3, and V5 but are vastly simplified compared with monkey visual cortex. Simulated area VOR contains both orientation and directionally selective units; simulated area VMO discriminates the direction of motion of arbitrarily oriented objects; and simulated area VOC responds to both luminance and occlusion boundaries in the stimulus. Area VOC is able to respond to illusory contours (Kanizsa, 1979) by means of the same neural architecture used for the discrimination of occlusion boundaries. This architecture also generates responses to structure-from-motion by virtue of reentrant connections from VMO to VOC. The responses of the simulated networks to these illusions are consistent with the perceptual responses of humans and other species presented with these stimuli. The networks also respond in a consistent manner to a novel illusion that combines illusory contours and structure-from-motion. The response synthesized to this combined illusion provides a strong argument supporting the need for a recursive reentrant process in the cortex. Functional integration of the simulated areas in the RCI model were found to depend upon the combined action of 3 reentrant processes: (1) conflicting responses among segregated areas are competitively eliminated, (2) outputs of each area are used by other areas in their own operations, and (3) outputs of an area are "reentered" back to itself (through lower areas) and can thus be used iteratively to synthesize responses to complex or illusory stimuli. Transection of the reentrant connections selectively abolished these integrative processes and led to failure of figural synthesis. The proposed model of reentry suggests a basis for understanding how multiple visual areas as well as other cortical areas may be integrated within a distributed system.  相似文献   
10.
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