全文获取类型
收费全文 | 3874篇 |
免费 | 117篇 |
国内免费 | 169篇 |
专业分类
4160篇 |
出版年
2024年 | 4篇 |
2023年 | 59篇 |
2022年 | 76篇 |
2021年 | 75篇 |
2020年 | 71篇 |
2019年 | 81篇 |
2018年 | 49篇 |
2017年 | 47篇 |
2016年 | 58篇 |
2015年 | 89篇 |
2014年 | 209篇 |
2013年 | 258篇 |
2012年 | 195篇 |
2011年 | 156篇 |
2010年 | 122篇 |
2009年 | 155篇 |
2008年 | 189篇 |
2007年 | 152篇 |
2006年 | 163篇 |
2005年 | 141篇 |
2004年 | 146篇 |
2003年 | 140篇 |
2002年 | 136篇 |
2001年 | 99篇 |
2000年 | 87篇 |
1999年 | 73篇 |
1998年 | 101篇 |
1997年 | 77篇 |
1996年 | 86篇 |
1995年 | 98篇 |
1994年 | 98篇 |
1993年 | 79篇 |
1992年 | 59篇 |
1991年 | 71篇 |
1990年 | 72篇 |
1989年 | 43篇 |
1988年 | 44篇 |
1987年 | 43篇 |
1986年 | 23篇 |
1985年 | 49篇 |
1984年 | 41篇 |
1983年 | 28篇 |
1982年 | 41篇 |
1981年 | 21篇 |
1980年 | 19篇 |
1979年 | 13篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 2篇 |
排序方式: 共有4160条查询结果,搜索用时 7 毫秒
201.
《Bioscience, biotechnology, and biochemistry》2013,77(11):1790-1794
We isolated cDNA clones encoding a transglutaminase (TGase: EC 2.3.2.13) from a salmon (Onchorhynchus keta) cDNA library prepared from the liver. In the cDNA sequence combined, an open reading frame coding for a protein of 680 aa was found. The deduced sequence showed a considerable similarity (62.4%) to that of red sea bream TGase. By comparison of sequence similarity to other TGases, the structure of salmon TGase was like tissue type TGases, rather than membrane-associated type or plasma type TGases. As a structural feature of salmon TGase, 3 aa residues were substituted in the 25 aa sequence around the active site Cys residue, which is conserved among several tissue type TGases. The critical residues thought to form the catalytic-center triad (Cys272, His331, and Asp301) were found in the highly conserved region, but the region surrounding Tyr511, which corresponds to the residue participates in hydrogen-bond interactions of active center domain, was less similar to other TGases, except for red sea bream TGase. These findings suggests that the overall structure of fish TGase resembles tissue-type TGases, but has some unique structure. 相似文献
202.
203.
204.
205.
206.
207.
Hélène Malka-Mahieu Isabelle Girault Margot Rubington Melissa Leriche Caroline Welsch Nyam Kamsu-Kom 《Cell cycle (Georgetown, Tex.)》2016,15(18):2405-2409
Activating mutations of the NRAS (neuroblastoma rat sarcoma viral oncogene) protein kinase, present in many cancers, induce a constitutive activation of both the RAS-RAF-MEK-ERK mitogen-activated protein kinase (MAPK) signal transduction pathway and the PI(3)K-AKT-mTOR, pathway. This in turn regulates the formation of the eIF4F eukaryotic translation initiation complex, comprising the eIF4E cap-binding protein, the eIF4G scaffolding protein and the eIF4A RNA helicase, which binds to the 7-methylguanylate cap (m(7)G) at the 5′ end of messenger RNAs. Small molecules targeting MEK (MEKi: MEK inhibitors) have demonstrated activity in NRAS-mutant cell lines and tumors, but resistance sets in most cases within months of treatment. Using proximity ligation assays, that allows visualization of the binding of eIF4E to the scaffold protein eIF4G, generating the active eIF4F complex, we have found that resistance to MEKi is associated with the persistent formation of the eIF4F complex in MEKi-treated NRAS-mutant cell lines. Furthermore, inhibiting the eIF4A component of the eIF4F complex, with a small molecule of the flavagline/rocaglate family, synergizes with inhibiting MEK to kill NRAS-mutant cancer cell lines. 相似文献
208.
Yuji Iwata Noriko Hayashi Kazuki Tabara Kei-ichiro Mishiba 《Bioscience, biotechnology, and biochemistry》2016,80(6):1168-1171
The N-glycosylation inhibitor tunicamycin triggers endoplasmic reticulum stress response and inhibits efficient protein secretion in eukaryotes. Using Arabidopsis suspension cells, we showed that the reduced secretion of mannose-binding lectin 1 (MBL1) protein by tunicamycin is accompanied by a significant decrease in MBL1 mRNA, suggesting that mRNA destabilization is the major cause of the inhibition of protein secretion in plants. 相似文献
209.
目的:应用实时荧光定量PCR(RT-PCR)技术对不同孕周孕妇外周血浆胎盘特异性基因4(PLAC4)m RNA基因进行检测,寻找唐氏综合征产前诊断的可靠生物学标志物,为无创性产前诊断提供新的突破口。方法:按入组标准随机选取健康育龄未妊娠女性5例,正常健康妊娠孕妇60例(早期妊娠20例、中期妊娠20例、晚期妊娠20例),唐氏筛查高危孕妇8例,正常分娩24 h女性5例。共收集外周血浆样本78例。应用RT-PCR技术,检测样本中的PLAC4 m RNA基因含量,并进行相对定量分析。结果:健康育龄未妊娠女性及正常分娩后24 h女性外周血浆中均无游离胎儿PLAC4 m RNA基因的存在;正常健康妊娠孕妇不同孕周标本均检测到PLAC4 m RNA基因,以早期妊娠作为对照,中期妊娠是早期妊娠的1.99倍,晚期妊娠是早期妊娠的3.73倍;唐氏筛查高危孕妇均检出PLAC4 m RNA基因,含量是早期妊娠的6.36倍。结论:PLAC4 m RNA基因有望成为唐氏综合征产前诊断的可靠性生物学标志物。 相似文献