全文获取类型
收费全文 | 1368497篇 |
免费 | 117463篇 |
国内免费 | 8663篇 |
专业分类
耳鼻咽喉 | 16989篇 |
儿科学 | 43377篇 |
妇产科学 | 36883篇 |
基础医学 | 186913篇 |
口腔科学 | 36809篇 |
临床医学 | 125485篇 |
内科学 | 281597篇 |
皮肤病学 | 32283篇 |
神经病学 | 111772篇 |
特种医学 | 56516篇 |
外国民族医学 | 293篇 |
外科学 | 212930篇 |
综合类 | 39056篇 |
现状与发展 | 8篇 |
一般理论 | 418篇 |
预防医学 | 109111篇 |
眼科学 | 28880篇 |
药学 | 97599篇 |
49篇 | |
中国医学 | 4322篇 |
肿瘤学 | 73333篇 |
出版年
2018年 | 14409篇 |
2017年 | 11722篇 |
2016年 | 13760篇 |
2015年 | 15947篇 |
2014年 | 22122篇 |
2013年 | 31840篇 |
2012年 | 39198篇 |
2011年 | 42092篇 |
2010年 | 26790篇 |
2009年 | 25865篇 |
2008年 | 38566篇 |
2007年 | 40925篇 |
2006年 | 41958篇 |
2005年 | 40226篇 |
2004年 | 37797篇 |
2003年 | 36795篇 |
2002年 | 34664篇 |
2001年 | 66675篇 |
2000年 | 68522篇 |
1999年 | 57175篇 |
1998年 | 17082篇 |
1997年 | 15425篇 |
1996年 | 16283篇 |
1995年 | 16478篇 |
1994年 | 15322篇 |
1993年 | 14190篇 |
1992年 | 47176篇 |
1991年 | 45855篇 |
1990年 | 44055篇 |
1989年 | 41856篇 |
1988年 | 38802篇 |
1987年 | 38127篇 |
1986年 | 35885篇 |
1985年 | 34662篇 |
1984年 | 26360篇 |
1983年 | 22076篇 |
1982年 | 13821篇 |
1981年 | 12420篇 |
1980年 | 11669篇 |
1979年 | 23513篇 |
1978年 | 17020篇 |
1977年 | 14336篇 |
1976年 | 13139篇 |
1975年 | 13694篇 |
1974年 | 16067篇 |
1973年 | 15379篇 |
1972年 | 14167篇 |
1971年 | 13023篇 |
1970年 | 11863篇 |
1969年 | 11092篇 |
排序方式: 共有10000条查询结果,搜索用时 484 毫秒
1.
2.
目的了解何首乌致药物性肝损伤(Polygonum multiflorum-associated drug induce liver injury,PM-DILI)的临床病理学特点。方法收集2019年3月1日至2021年3月1日深圳市第三人民医院收治的8例PM-DILI患者临床资料。肝穿组织进行苏木素-伊红染色、网状纤维染色、Masson三色染色、铁、铜特殊染色和免疫组织化学染色,显微镜下观察分析。结果8例PM-DILI患者男女比为1∶1,平均年龄43岁,其中6例为急性PM-DILI,2例慢性为PM-DILI。入院血清学检查异常主要包括转氨酶升高和淤胆均为7例。主要组织病理学改变为点灶状坏死8例、界面炎5例、融合坏死4例,融合坏死以肝腺泡3带为主,不伴或伴少数炎细胞浸润;胆汁淤积5例,为肝腺泡3带的肝细胞、毛细胆管内淤胆,不伴或伴少数炎细胞浸润;中央静脉炎3例;病程长者可发生肝纤维化,甚至肝硬化2例。结论肝腺泡3带为主的急性淤胆和肝细胞坏死是PM-DILI主要组织学表现,严重者可发生静脉炎等血管损伤。 相似文献
3.
4.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses... 相似文献
5.
Qian Zhang Larry D. Mesner Gina M. Calabrese Naomi Dirckx Zhu Li Angela Verardo Qian Yang Robert J. Tower Marie-Claude Faugere Charles R. Farber Thomas L. Clemens 《The Journal of clinical investigation》2021,131(7)
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass. 相似文献
6.
7.
8.
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
9.
10.