全文获取类型
收费全文 | 185809篇 |
免费 | 14812篇 |
国内免费 | 13183篇 |
出版年
2024年 | 72篇 |
2023年 | 2089篇 |
2022年 | 2543篇 |
2021年 | 8662篇 |
2020年 | 6011篇 |
2019年 | 7489篇 |
2018年 | 7424篇 |
2017年 | 5554篇 |
2016年 | 7812篇 |
2015年 | 11232篇 |
2014年 | 13284篇 |
2013年 | 14096篇 |
2012年 | 16913篇 |
2011年 | 15461篇 |
2010年 | 9486篇 |
2009年 | 8581篇 |
2008年 | 9967篇 |
2007年 | 8713篇 |
2006年 | 7651篇 |
2005年 | 6196篇 |
2004年 | 5382篇 |
2003年 | 4745篇 |
2002年 | 4072篇 |
2001年 | 3617篇 |
2000年 | 3287篇 |
1999年 | 3320篇 |
1998年 | 1903篇 |
1997年 | 2050篇 |
1996年 | 1802篇 |
1995年 | 1688篇 |
1994年 | 1599篇 |
1993年 | 1211篇 |
1992年 | 1708篇 |
1991年 | 1406篇 |
1990年 | 1100篇 |
1989年 | 940篇 |
1988年 | 781篇 |
1987年 | 645篇 |
1986年 | 595篇 |
1985年 | 600篇 |
1984年 | 354篇 |
1983年 | 323篇 |
1982年 | 198篇 |
1981年 | 144篇 |
1980年 | 136篇 |
1979年 | 139篇 |
1978年 | 84篇 |
1977年 | 69篇 |
1974年 | 79篇 |
1972年 | 73篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Li Zhang Mark Morrison Páraic ó Cuív Paul Evans Claire M. Rickard 《Journal of bacteriology》2012,194(23):6639
In recent years, Staphylococcus epidermidis has become a major nosocomial pathogen and the most common cause of intravascular catheter-related bacteremia, which can increase morbidity and mortality and significantly affect patient recovery. We report a draft genome sequence of Staphylococcus epidermidis AU12-03, isolated from an intravascular catheter tip. 相似文献
22.
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
23.
24.
Comment on: Rokavec M, et al. Mol Cell 2012; 45:777-89. 相似文献
25.
The effect of estradiol on the brain concentration of immunoreactive beta-endorphin (beta-EP) and C-terminal ACTH (CLIP) was studied in ovariectomized rats. Dopamine, a known inhibitor of pituitary intermediate lobe pro-opiomelanocortin (POMC), was examined as a possible mediator of the estradiol induced changes in brain POMC. Animals were treated for 1 or 3 weeks with either 1) saline; 2) silastic estradiol implants; or 3) estradiol implants plus haloperidol 1 mg/kg/day. After one week of treatment no significant change in hypothalamic beta-EP content was noted in any group compared to the control level of 4.13 +/- .33 (SEM) pmoles although in the neurointermediate lobe beta-EP increased from 566 +/- 72 to 942 +/- 73 pmoles after haloperidol (p less than .005). After 3 weeks, however, hypothalamic beta-EP decreased from 3.96 +/- .28 to 2.74 +/- .19 pmoles (p less than .005) and C-terminal ACTH decreased from 3.78 +/- .33 to 2.82 +/- .18 pmoles (p less than .02) in the estradiol treated rats. This estradiol induced decrease in the hypothalamic content of beta-EP and C-terminal ACTH was not blocked by haloperidol. We conclude that estradiol lowers the hypothalamic content of beta-EP and CLIP and that this effect does not appear to be mediated by dopamine. 相似文献
26.
27.
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
28.
Jin Wei Mia Madel Alfajaro Peter C. DeWeirdt Ruth E. Hanna William J. Lu-Culligan Wesley L. Cai Madison S. Strine Shang-Min Zhang Vincent R. Graziano Cameron O. Schmitz Jennifer S. Chen Madeleine C. Mankowski Renata B. Filler Neal G. Ravindra Victor Gasque Fernando J. de Miguel Ajinkya Patil Huacui Chen Craig B. Wilen 《Cell》2021,184(1):76-91.e13
29.
30.
We isolated a recombinant H9N2 avian influenza virus (AIV) from fresh egret feces in the Ardeidae protection region of the Dongting Lake wetland area in China, and it was designated A/Egret/Hunan/1/2012(H9N2). This is the first report of isolating H9N2 AIV from wild birds in the Dongting Lake wetland. Its eight gene segments are generated by reassortment of gene segments of different AIV subtypes. These results are helpful for understanding the epidemiology and evolution of AIV in wild birds during migration. 相似文献