全文获取类型
收费全文 | 27641篇 |
免费 | 2590篇 |
国内免费 | 3535篇 |
出版年
2024年 | 46篇 |
2023年 | 432篇 |
2022年 | 599篇 |
2021年 | 1445篇 |
2020年 | 1048篇 |
2019年 | 1317篇 |
2018年 | 1233篇 |
2017年 | 935篇 |
2016年 | 1236篇 |
2015年 | 1832篇 |
2014年 | 2160篇 |
2013年 | 2250篇 |
2012年 | 2667篇 |
2011年 | 2400篇 |
2010年 | 1581篇 |
2009年 | 1374篇 |
2008年 | 1644篇 |
2007年 | 1432篇 |
2006年 | 1275篇 |
2005年 | 1077篇 |
2004年 | 905篇 |
2003年 | 807篇 |
2002年 | 693篇 |
2001年 | 458篇 |
2000年 | 408篇 |
1999年 | 380篇 |
1998年 | 272篇 |
1997年 | 224篇 |
1996年 | 188篇 |
1995年 | 165篇 |
1994年 | 191篇 |
1993年 | 106篇 |
1992年 | 126篇 |
1991年 | 129篇 |
1990年 | 116篇 |
1989年 | 106篇 |
1988年 | 63篇 |
1987年 | 49篇 |
1986年 | 73篇 |
1985年 | 53篇 |
1984年 | 42篇 |
1983年 | 38篇 |
1982年 | 26篇 |
1981年 | 22篇 |
1980年 | 16篇 |
1979年 | 23篇 |
1978年 | 12篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
FAB1/PIKfyve是介导PI(3,5)P2 (磷脂酰肌醇3,5-二磷酸)生物合成的磷酸肌醇激酶。在动物和酵母(Saccharomyces cerevisiae)中, PI(3,5)P2参与调控胞内膜运输, 但在植物中的研究较少。该文通过分析拟南芥(Arabidopsis thaliana) FAB1的T-DNA插入突变体的表型解析PI(3,5)P2的生物学功能。拟南芥FAB1基因家族包含FAB1A、FAB1B、FAB1C和FAB1D四个基因。研究发现, fab1a/b呈现雄配子体致死的表型。利用遗传杂交获得fab1b/c/d三突变体, 发现FAB1B、FAB1C和FAB1D功能缺失导致根毛相比野生型变短, 经FAB1特异性抑制剂YM201636处理后的野生型中也观察到相似的短根毛表型。此外, fab1b/c/d三突变体中DR5转录水平降低。同时, 外源施加生长素类似物2,4-D和NAA能部分恢复fab1b/c/d植株短根毛的表型, 但fab1b/c/d突变体对生长素转运抑制剂(1-NOA和TIBA)的敏感性与野生型相似。此外, FAB1B/C/D功能缺失使根毛中ROS的含量减少且影响肌动蛋白的表达。上述结果表明, FAB1B/C/D通过调控生长素分布、ROS含量和肌动蛋白的表达影响拟南芥根毛伸长。 相似文献
3.
4.
5.
6.
Tao Tian Danhua Yao Lei Zheng Zhiyuan Zhou Yantao Duan Bin Liu Pengfei Wang Yousheng Li 《Cell death & disease》2020,11(12)
Previously, we confirmed that sphingosine kinase 1 (SphK1) inhibition improves sepsis-associated liver injury. High-mobility group box 1 (HMGB1) translocation participates in the development of acute liver failure. However, little information is available on the association between SphK1 and HMGB1 translocation during sepsis-associated liver injury. In the present study, we aimed to explore the effect of SphK1 inhibition on HMGB1 translocation and the underlying mechanism during sepsis-associated liver injury. Primary Kupffer cells and hepatocytes were isolated from SD rats. The rat model of sepsis-associated liver damage was induced by intraperitoneal injection with lipopolysaccharide (LPS). We confirmed that Kupffer cells were the cells primarily secreting HMGB1 in the liver after LPS stimulation. LPS-mediated HMGB1 expression, intracellular translocation, and acetylation were dramatically decreased by SphK1 inhibition. Nuclear histone deacetyltransferase 4 (HDAC4) translocation and E1A-associated protein p300 (p300) expression regulating the acetylation of HMGB1 were also suppressed by SphK1 inhibition. HDAC4 intracellular translocation has been reported to be controlled by the phosphorylation of HDAC4. The phosphorylation of HDAC4 is modulated by CaMKII-δ. However, these changes were completely blocked by SphK1 inhibition. Additionally, by performing coimmunoprecipitation and pull-down assays, we revealed that SphK1 can directly interact with CaMKII-δ. The colocalization of SphK1 and CaMKII-δ was verified in human liver tissues with sepsis-associated liver injury. In conclusion, SphK1 inhibition diminishes HMGB1 intracellular translocation in sepsis-associated liver injury. The mechanism is associated with the direct interaction of SphK1 and CaMKII-δ.Subject terms: Hepatotoxicity, Sepsis 相似文献
7.
Plant and Soil - To investigate the effects of polystyrene microplastics (PS-beads) on the soil properties, photosynthesis of Flowering Chinese cabbage, the rhizosphere microbial community and... 相似文献
8.
Correlation between bilayer destabilization and activity enhancement by diacylglycerols in reconstituted Ca-ATPase vesicles 总被引:1,自引:0,他引:1
Using the reconstituted Ca-ATPase vesicles as a model system, we demonstrated that the presence of 1,2-dioleoyl-sn-glycerol (diolein) in the membrane introduces a pronounced enhancement in the Ca-transport function of Ca-ATPase, while the 1,2-dipalmitoyl-sn-glycerol (dipalmitin) does not. We also found by both 31P NMR and freeze-fraction electron microscopy that diolein destabilized lipid bilayers to a greater extent than did dipalmitin. We conclude that the tendency of diacylglycerols to destabilize the phospholipid bilayer is related to their capacity to enhance the activity of the membrane calcium pump. 相似文献
9.
10.