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   46059篇
  免费   3497篇
  国内免费   148篇
耳鼻咽喉   468篇
儿科学   1243篇
妇产科学   898篇
基础医学   6715篇
口腔科学   797篇
临床医学   4986篇
内科学   9770篇
皮肤病学   971篇
神经病学   4785篇
特种医学   1649篇
外国民族医学   11篇
外科学   6038篇
综合类   503篇
一般理论   31篇
预防医学   3805篇
眼科学   845篇
药学   3191篇
中国医学   133篇
肿瘤学   2865篇
  2023年   381篇
  2022年   586篇
  2021年   1349篇
  2020年   924篇
  2019年   1160篇
  2018年   1366篇
  2017年   1075篇
  2016年   1247篇
  2015年   1336篇
  2014年   1751篇
  2013年   2209篇
  2012年   3416篇
  2011年   3527篇
  2010年   1989篇
  2009年   1674篇
  2008年   2706篇
  2007年   2785篇
  2006年   2666篇
  2005年   2448篇
  2004年   2265篇
  2003年   1913篇
  2002年   1803篇
  2001年   653篇
  2000年   642篇
  1999年   592篇
  1998年   407篇
  1997年   297篇
  1996年   289篇
  1995年   257篇
  1994年   223篇
  1993年   168篇
  1992年   332篇
  1991年   309篇
  1990年   317篇
  1989年   256篇
  1988年   263篇
  1987年   282篇
  1986年   289篇
  1985年   276篇
  1984年   237篇
  1983年   187篇
  1982年   143篇
  1981年   125篇
  1980年   126篇
  1979年   241篇
  1978年   171篇
  1977年   144篇
  1975年   129篇
  1974年   130篇
  1973年   142篇
排序方式: 共有10000条查询结果,搜索用时 640 毫秒
201.
During myogenesis in Drosophila embryos, a prominent adhesive structure is formed between precursor cells and fusion-competent myoblasts (fcms). Here, we show that Duf/Kirre and its interaction partners Rols7 (found in founder myoblasts and growing myotubes) and Sns (found in fcms) are organized in a ring-structure at the contact points of fcms with precursor cells, while cytoskeletal components like F-actin and Titin are centered in this ring in both cell types. The cytoplasmic protein Blow colocalizes with the actin plugs in fcms after cell adhesion. Furthermore, the requirement of additional as yet unidentified components was demonstrated by using mammalian C2C12 myoblasts. In this study, we propose that the fusion-restricted myogenic-adhesive structure (FuRMAS) is pivotal in linking cell adhesion as well as local F-actin assembly and dynamics to downstream events that ultimately lead to plasma membrane fusion. Moreover, we suggest that the FuRMAS may restrict the area of membrane breakdown.  相似文献   
202.

Background  

It is often stated that external validity is not sufficiently considered in the assessment of clinical studies. Although tools for its evaluation have been established, there is a lack of awareness of their significance and application. In this article, a comprehensive checklist is presented addressing these relevant criteria.  相似文献   
203.
204.
205.
In the present study, we measured the striatal serotonin content of weaver and control mice at different ages. Overall, weaver mutant mice exhibited 50% more striatal serotonin than controls. Neither a rostrocaudal gradient nor an age effect was found for either genotype. An analysis of serotonin content across the dorsoventral extent of the striatum revealed that in the dorsal striatum of the weaver, serotonin content was increased 200%, and in the ventral striatum, the increase amounted to 50% relative to control mice. Serotonin immunocytochemistry also revealed an increase in the dorsal striata of weaver mice. The major increase in striatal serotonin content seen in the weaver striatum occurs in the same region that exhibits the severest dopamine depletion. This observation is consistent with the notion that the increase in serotonin levels may be secondary to the decrease in dopamine content and may play an adaptive or compensatory role.  相似文献   
206.
We report on a 45-year-old man with a history of multiple psychiatric admissions for a gait disorder and episodic weakness thought to be psychogenic who was subsequently diagnosed with status cataplecticus due to narcolepsy. The gait difficulties resolved with venlafaxine. This case demonstrates that status cataplecticus can be misdiagnosed as a psychogenic gait disorder.  相似文献   
207.
Partial k-space sampling is frequently used in single-shot diffusion-weighted echo-planar imaging (DW-EPI) to reduce the TE and thereby improve the SNR. However, it increases the sensitivity of the technique to bulk rotational motion, which introduces a phase gradient across the tissue that shifts the echo in k-space. If the echo is displaced into the high spatial frequencies, conventional homodyne reconstruction fails, causing intensity oscillations across the image. Zero-padding, on the other hand, compromises the image resolution and may cause truncation artifacts. We present an adaptive version of the homodyne algorithm that detects the location of the echo in k-space and adjusts the center and width of the homodyne filters accordingly. The adaptive algorithm produces artifact-free images when the echo is shifted into the high positive k-space range, and reduces to the standard homodyne algorithm in the absence of bulk motion.  相似文献   
208.
Digital dermatoglyphics of a sample from the Basque Valley of Salazar, situated in the West of the Pyrenees, were analysed. The results showed bimanual differences in both sexes, and also sexual differences for both hands. The comparative study with other Basque valleys showed that, in spite of their supposed common origin, the geographic barriers and the isolation have generated a genetic/dermatoglyphic and linguistic differentiation.  相似文献   
209.
Seven systems for the diagnosis of schizophrenia were compared in their ability to predict short-term outcome at follow-up: with each other, with selected specific symptoms, and with a simple additive composite symptom score. None of the systems nor the symptoms predicted strongly, but DSM-III and Schneiderian First Rank Symptoms and the composite score performed somewhat better than the other predictors.  相似文献   
210.
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