全文获取类型
收费全文 | 2208084篇 |
免费 | 174591篇 |
国内免费 | 7647篇 |
专业分类
耳鼻咽喉 | 29301篇 |
儿科学 | 73773篇 |
妇产科学 | 62397篇 |
基础医学 | 316571篇 |
口腔科学 | 60538篇 |
临床医学 | 201786篇 |
内科学 | 432188篇 |
皮肤病学 | 50756篇 |
神经病学 | 179140篇 |
特种医学 | 84249篇 |
外国民族医学 | 776篇 |
外科学 | 327525篇 |
综合类 | 58020篇 |
现状与发展 | 14篇 |
一般理论 | 819篇 |
预防医学 | 174511篇 |
眼科学 | 50975篇 |
药学 | 158377篇 |
30篇 | |
中国医学 | 6719篇 |
肿瘤学 | 121857篇 |
出版年
2021年 | 17820篇 |
2019年 | 18246篇 |
2018年 | 25459篇 |
2017年 | 19804篇 |
2016年 | 22148篇 |
2015年 | 25234篇 |
2014年 | 35093篇 |
2013年 | 51748篇 |
2012年 | 69654篇 |
2011年 | 73985篇 |
2010年 | 43787篇 |
2009年 | 41395篇 |
2008年 | 67774篇 |
2007年 | 71753篇 |
2006年 | 72708篇 |
2005年 | 70304篇 |
2004年 | 67167篇 |
2003年 | 64215篇 |
2002年 | 61930篇 |
2001年 | 106233篇 |
2000年 | 108898篇 |
1999年 | 91000篇 |
1998年 | 26058篇 |
1997年 | 23644篇 |
1996年 | 23527篇 |
1995年 | 22442篇 |
1994年 | 20559篇 |
1993年 | 19114篇 |
1992年 | 69666篇 |
1991年 | 67144篇 |
1990年 | 65071篇 |
1989年 | 62317篇 |
1988年 | 56882篇 |
1987年 | 56374篇 |
1986年 | 52641篇 |
1985年 | 50419篇 |
1984年 | 38182篇 |
1983年 | 32212篇 |
1982年 | 19577篇 |
1979年 | 34404篇 |
1978年 | 24479篇 |
1977年 | 20489篇 |
1976年 | 19332篇 |
1975年 | 20067篇 |
1974年 | 24327篇 |
1973年 | 23434篇 |
1972年 | 21734篇 |
1971年 | 19992篇 |
1970年 | 18887篇 |
1969年 | 17489篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Patrick W. Keeley Mikayla C. Lebo Jordan D. Vieler Jason J. Kim Ace J. St. John Benjamin E. Reese 《The Journal of neuroscience》2021,41(1):103
Amacrine cells of the retina are conspicuously variable in their morphologies, their population demographics, and their ensuing functions. Vesicular glutamate transporter 3 (VGluT3) amacrine cells are a recently characterized type of amacrine cell exhibiting local dendritic autonomy. The present analysis has examined three features of this VGluT3 population, including their density, local distribution, and dendritic spread, to discern the extent to which these are interrelated, using male and female mice. We first demonstrate that Bax-mediated cell death transforms the mosaic of VGluT3 cells from a random distribution into a regular mosaic. We subsequently examine the relationship between cell density and mosaic regularity across recombinant inbred strains of mice, finding that, although both traits vary across the strains, they exhibit minimal covariation. Other genetic determinants must therefore contribute independently to final cell number and to mosaic order. Using a conditional KO approach, we further demonstrate that Bax acts via the bipolar cell population, rather than cell-intrinsically, to control VGluT3 cell number. Finally, we consider the relationship between the dendritic arbors of single VGluT3 cells and the distribution of their homotypic neighbors. Dendritic field area was found to be independent of Voronoi domain area, while dendritic coverage of single cells was not conserved, simply increasing with the size of the dendritic field. Bax-KO retinas exhibited a threefold increase in dendritic coverage. Each cell, however, contributed less dendrites at each depth within the plexus, intermingling their processes with those of neighboring cells to approximate a constant volumetric density, yielding a uniformity in process coverage across the population.SIGNIFICANCE STATEMENT Different types of retinal neuron spread their processes across the surface of the retina to achieve a degree of dendritic coverage that is characteristic of each type. Many of these types achieve a constant coverage by varying their dendritic field area inversely with the local density of like-type neighbors. Here we report a population of retinal amacrine cells that do not develop dendritic arbors in relation to the spatial positioning of such homotypic neighbors; rather, this cell type modulates the extent of its dendritic branching when faced with a variable number of overlapping dendritic fields to approximate a uniformity in dendritic density across the retina. 相似文献
15.
16.
Kara S. Tanaka MD Veronica R. Andaya BA Steven W. Thorpe MD Kenneth R. Gundle MD James B. Hayden MD Yee-Cheen Duong MD Raffi S. Avedian MD David G. Mohler MD Lee J. Morse MD Melissa N. Zimel MD Richard J. O'Donnell MD Andrew Fang MD Robert Lor Randall MD Tina H. Tran BS Christin New BA Rosanna L. Wustrack MD other members of Study Group FORCE 《Journal of surgical oncology》2023,127(1):148-158
17.
Major depressive disorder and other neuropsychiatric disorders are often managed with long-term use of antidepressant medication. Fluoxetine, an SSRI antidepressant, is widely used as a first-line treatment for neuropsychiatric disorders. However, fluoxetine has also been shown to increase the risk of metabolic diseases such as non-alcoholic fatty liver disease. Fluoxetine has been shown to increase hepatic lipid accumulation in vivo and in vitro. In addition, fluoxetine has been shown to alter the production of prostaglandins which have also been implicated in the development of non-alcoholic fatty liver disease. The goal of this study was to assess the effect of fluoxetine exposure on the prostaglandin biosynthetic pathway and lipid accumulation in a hepatic cell line (H4-II-E-C3 cells). Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes (Ptgs1, Ptgs2, and Ptgds), PPAR gamma (Pparg), and PPAR gamma downstream targets involved in fatty acid uptake (Cd36, Fatp2, and Fatp5) as well as production of 15-deoxy-Δ12,14PGJ2 a PPAR gamma ligand. The effects of fluoxetine to induce lipid accumulation were attenuated with a PTGS1 specific inhibitor (SC-560), whereas inhibition of PTGS2 had no effect. Moreover, SC-560 attenuated 15-deoxy-Δ12,14PGJ2 production and expression of PPAR gamma downstream target genes. Taken together these results suggest that fluoxetine-induced lipid abnormalities appear to be mediated via PTGS1 and its downstream product 15d-PGJ2 and suggest a novel therapeutic target to prevent some of the adverse effects of fluoxetine treatment. 相似文献
18.
Deitelzweig Steve Luo Xuemei Nguyen Jennifer L. Malhotra Deepa Emir Birol Russ Cristina Li Xiaoyan Lee Theodore C. Ferri Mauricio Wiederkehr Danny Reimbaeva Maya Barnes Geoffrey D. Piazza Gregory 《Journal of thrombosis and thrombolysis》2022,54(4):696-696
Journal of Thrombosis and Thrombolysis - 相似文献
19.
Boffa Joseph W. Tock Jamie L. Morabito Danielle M. Schmidt Norman B. 《Cognitive therapy and research》2022,46(5):1016-1029
Cognitive Therapy and Research - Despite interest in psychological inflexibility as a marker of suicide risk, no measure of psychological inflexibility specific to SI exists. The present study... 相似文献
20.