全文获取类型
收费全文 | 286篇 |
免费 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 13篇 |
2014年 | 10篇 |
2013年 | 25篇 |
2012年 | 26篇 |
2011年 | 26篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 13篇 |
2003年 | 13篇 |
2002年 | 5篇 |
2001年 | 12篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有301条查询结果,搜索用时 15 毫秒
1.
2.
C A Lunn J Fossetta N Murgolo P J Zavodny D Lundell S K Narula 《Protein engineering》1992,5(3):249-252
We have identified a mutation of human gamma-interferon (IFN gamma) causing a temperature-sensitive phenotype. We used a randomized oligonucleotide to mutagenize a synthetic human IFN gamma gene, then screened the resulting mutants produced in Escherichia coli for proteins with altered biological activity. One mutant protein selected for detailed characterization exhibited less than 0.3% of the specific biological activity of native IFN gamma in an antiviral activity assay performed at 37 degrees C. However, the protein bound the human IFN gamma receptor with native efficiency at 4 degrees C. Sequencing the plasmid DNA encoding this protein showed that the mutation changed the lysine residue at amino acid 43 to glutamic acid (IFN gamma/K43E). Site-specific mutagenesis at amino acid 43 showed that this protein's phenotype resulted from positioning a negative charge at position 43. Structural characterization of IFN gamma/K43E using CD demonstrated that the protein had native conformation at 25 degrees C, but assumed an altered conformation at 37 degrees C. IFN gamma/K43E in this altered conformation bound poorly to the IFN gamma receptor at 37 degrees C, providing a rationale for the mutant's decreased antiviral activity. 相似文献
3.
4.
5.
Anubhav P. S. Narula 《化学与生物多样性》2014,11(10):1629-1638
There is a constant need for developing new fragrance ingredients in the flavor and fragrance industry, as it allows perfumers to create unique and differentiating perfumes for fine as well as functional products. Among all the categories of notes used in perfume creation, amber notes are indispensible and ubiquitous in their presence in all perfumes. Not only amber notes impart high performance and substantivity to fragrances, but they are paramount in the development of classic and legendary fragrances. This article is based on the plenary lecture delivered at the flavor & fragrance 2013 conference of the German Chemical Society in Leipzig, Germany. The strategy, rationale, and the various synthetic approaches that led to the discovery of two new very powerful, woody, amber materials, Amber Xtreme® ( 1 ) and Trisamber® ( 2 ), are delineated. 相似文献
6.
Summary Heavy metal, antibiotic resistance and hydrocarbon utilization properties were studied inAzotobactor
chroococcum to investigate the nature and role of plasmids in different soil isolates. There is wide prevalence of heavy metal resistance, antibiotic resistance and utilization of hydrocarbons; the heavy metal resistance property seems to be conferred by plasmids. 相似文献
7.
8.
9.
Abstract The self-association of puromycin has been studied using proton magnetic resonance spectroscopy. The concentration, temperature and pH dependence studies of the proton chemical shifts of the adenine protons indicate that puromycin in aqueous solution at pD 7.4 self associates predominantly through adenine-adenine interaction. At this pD, the amino group of the aminoacyl segment of puromycin has been demonstrated to exist in a equilibrium blend of protonated and non-protonated forms. At pD 2.6, PM is found to exist predominantly in the monomeric from in which the methyl groups of the 6N-dimethyladenine are found to be non-equivalent due to hindered rotation about the C6-N6 bond. 相似文献
10.
François Bilodeau Murray D. Bailey Punit K. Bhardwaj Josée Bordeleau Pat Forgione Michel Garneau Elise Ghiro Vida Gorys Ted Halmos Eric S. Jolicoeur Mélissa Leblanc Christopher T. Lemke Julie Naud Jeff O’Meara Peter W. White Montse Llinàs-Brunet 《Bioorganic & medicinal chemistry letters》2013,23(14):4267-4271
In this report we describe the synthesis and evaluation of diverse 4-arylproline analogs as HCV NS3 protease inhibitors. Introduction of this novel P2 moiety opened up new SAR and, in combination with a synthetic approach providing a versatile handle, allowed for efficient exploitation of this novel series of NS3 protease inhibitors. Multiple structural modifications of the aryl group at the 4-proline, guided by structural analysis, led to the identification of analogs which were very potent in both enzymatic and cell based assays. The impact of this systematic SAR on different drug properties is reported. 相似文献