全文获取类型
收费全文 | 9846篇 |
免费 | 874篇 |
国内免费 | 843篇 |
专业分类
11563篇 |
出版年
2024年 | 26篇 |
2023年 | 155篇 |
2022年 | 332篇 |
2021年 | 572篇 |
2020年 | 400篇 |
2019年 | 436篇 |
2018年 | 423篇 |
2017年 | 307篇 |
2016年 | 432篇 |
2015年 | 608篇 |
2014年 | 782篇 |
2013年 | 756篇 |
2012年 | 925篇 |
2011年 | 777篇 |
2010年 | 540篇 |
2009年 | 423篇 |
2008年 | 460篇 |
2007年 | 493篇 |
2006年 | 407篇 |
2005年 | 340篇 |
2004年 | 301篇 |
2003年 | 233篇 |
2002年 | 201篇 |
2001年 | 175篇 |
2000年 | 156篇 |
1999年 | 154篇 |
1998年 | 71篇 |
1997年 | 69篇 |
1996年 | 72篇 |
1995年 | 52篇 |
1994年 | 63篇 |
1993年 | 51篇 |
1992年 | 75篇 |
1991年 | 59篇 |
1990年 | 39篇 |
1989年 | 51篇 |
1988年 | 29篇 |
1987年 | 33篇 |
1986年 | 24篇 |
1985年 | 25篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
881.
882.
Molecular cloning of six novel Krüppel-like zinc finger genes from hematopoietic cells and identification of a novel transregulatory domain KRNB 总被引:4,自引:0,他引:4
883.
Synthetic antidepressants in current use for the complex etiopathogeneses of depression have slow response and remission as well as various unpleasant side effects. As a result, it is imperative to develop new antidepressants with more effectiveness and less severe side effects. Recent studies demonstrated that genipin, the aglycon of geniposide, extracted from Gardenia jasminoides Ellis has antidepressive effects. However, knowledge regarding the molecular mechanisms of its antidepressant effects remains limited. Employing a depression-like mouse model, we confirmed that genipin is capable of correcting depressions-like behaviors induced by prenatal stress in offspring from prenatally stressed dams (defined as PRS mice). In further experiments, we found that the effect of genipin on PRS mice occurs through DNA demethylation by inhibiting DNA methyltransferase 1 (DNMT1), normalizing the expression of reduced brain-derived neurotrophic factor (BDNF) in the hippocampus. 相似文献
884.
Ye Chen Feng Hong Hui Chen Rui-Fang Fan Xiao-Li Zhang Yue Zhang Jin-Xia Zhu 《Cell and tissue research》2014,357(3):597-606
Activation of the dopamine (DA) D2 receptor inhibits glucose-stimulated insulin secretion in isolated rodent islets in vitro; however, no information is available regarding the cellular localization of DA receptors (DRs, including D1-D5 receptors) in pancreatic islets in situ. We investigate the protein expression and cellular localization of five types of DRs in pancreatic islets by means of Western blotting and double-labeling immunofluorescence in both normal control and alloxan-induced type 1 diabetes model (T1DM) rats. In control rats, D1 immunoreactivity (-IR) was distributed in the core of the islet and co-localized with insulin-IR, D2-IR was peripherally distributed and found only in somatostatin-immunoreactive cells and D5-IR was co-localized with glucagon-IR and pancreatic polypeptide-IR. No IR for either the D3 or D4 receptor was observed in rat islets. The protein level of the D1 receptor was reduced in T1DM rats (D1/D-glyceraldehyde-3-phosphate dehydrogenase [GAPDH], 0.63?±?0.05 in control rats compared with 0.16?±?0.03 in T1DM rats, n?=?8, P?0.05) but no significant alteration was detected in the protein expression of either the D2 receptor (D2/GAPDH, 0.48?±?0.04 compared with 0.43?±?0.04, n?=?8, P?=?0.42) or the D5 receptor (D5/GAPDH, 0.50?±?0.04 compared with 0.47?±?0.04, n?=?8, P?=?0.58). The present study is the first clear demonstration of the protein expression and cellular localization of the D1, D2 and D5 receptors in rat pancreatic islets and provides crucial morphological evidence for further investigations of the underlying mechanism regarding the DA regulation of pancreatic endocrine function. 相似文献
885.
Optoelectronic Devices: Low‐Temperature Combustion‐Synthesized Nickel Oxide Thin Films as Hole‐Transport Interlayers for Solution‐Processed Optoelectronic Devices (Adv. Energy Mater. 6/2014) 下载免费PDF全文
886.
887.
Huifang M. Zhang Ye Qiu Guangze Zhao Hua Wang Yankuan T. Chen Sana Aghakeshmiri Paul Hanson Decheng Yang 《Cellular microbiology》2020,22(7)
Our previous study of coxsackievirus B3 (CVB3)‐induced unfolded protein responses (UPR) found that overexpression of ATF6a enhances CVB3 VP1 capsid protein production and increases viral particle formation. These findings implicate that ATF6a signalling benefits CVB3 replication. However, the mechanism by which ATF6a signalling is transduced to promote virus replication is unclear. In this study, using a Tet‐On inducible ATF6a HeLa cell line, we found that ATF6a signalling downregulated the protein expression of the endoplasmic reticulum (ER) degradation‐enhancing α‐mannosidase‐like protein 1 (EDEM1), resulting in accumulation of CVB3 VP1 protein; in contrast, expression of a dominant negative ATF6a had the opposite effect. Furthermore, we found that EDEM1 was cleaved by both CVB3 protease 3C and virus‐activated caspase and subsequently degraded via the ubiquitin‐proteasome pathway. However, overexpression of EDEM1 caused VP1 degradation, likely via a glycosylation‐independent and ubiquitin‐lysosome pathway. Finally, we demonstrated that CRISPR/Cas9‐mediated knockout of EDEM1 increased VP1 accumulation and thus CVB3 replication. This is the first study to report the ER protein quality control of non‐enveloped RNA virus and reveals a novel mechanism by which CVB3 evades host ER quality control pathways through cleavage and degradation of the UPR target gene EDEM1, to ultimately benefit its own replication. 相似文献
888.
Xiaoli Hu Rui Li Yanqing Wu Yi Li Xingfeng Zhong Guanyinsheng Zhang Yanmin Kang Shuhua Liu Ling Xie Junming Ye Jian Xiao 《Journal of cellular and molecular medicine》2020,24(14):8166-8178
The application of growth factors (GFs) for treating chronic spinal cord injury (SCI) has been shown to promote axonal regeneration and functional recovery. However, direct administration of GFs is limited by their rapid degradation and dilution at the injured sites. Moreover, SCI recovery is a multifactorial process that requires multiple GFs to participate in tissue regeneration. Based on these facts, controlled delivery of multiple growth factors (GFs) to lesion areas is becoming an attractive strategy for repairing SCI. Presently, we developed a GFs‐based delivery system (called GFs‐HP) that consisted of basic fibroblast growth factor (bFGF), nerve growth factor (NGF) and heparin‐poloxamer (HP) hydrogel through self‐assembly mode. This GFs‐HP was a kind of thermosensitive hydrogel that was suitable for orthotopic administration in vivo. Meanwhile, a 3D porous structure of this hydrogel is commonly used to load large amounts of GFs. After single injection of GFs‐HP into the lesioned spinal cord, the sustained release of NGF and bFGF from HP could significantly improve neuronal survival, axon regeneration, reactive astrogliosis suppression and locomotor recovery, when compared with the treatment of free GFs or HP. Moreover, we also revealed that these neuroprotective and neuroregenerative effects of GFs‐HP were likely through activating the phosphatidylinositol 3 kinase and protein kinase B (PI3K/Akt) and mitogen‐activated protein kinase/extracellular signal‐regulated kinase (MAPK/ERK) signalling pathways. Overall, our work will provide an effective therapeutic strategy for SCI repair. 相似文献
889.
890.