全文获取类型
收费全文 | 1543940篇 |
免费 | 32157篇 |
国内免费 | 8323篇 |
专业分类
化学 | 672199篇 |
晶体学 | 20456篇 |
力学 | 75116篇 |
综合类 | 105篇 |
数学 | 242618篇 |
物理学 | 376368篇 |
无线电 | 197558篇 |
出版年
2021年 | 14825篇 |
2020年 | 17404篇 |
2019年 | 17541篇 |
2018年 | 14968篇 |
2017年 | 13235篇 |
2016年 | 30428篇 |
2015年 | 21939篇 |
2014年 | 32860篇 |
2013年 | 78758篇 |
2012年 | 40936篇 |
2011年 | 38692篇 |
2010年 | 40681篇 |
2009年 | 45540篇 |
2008年 | 41402篇 |
2007年 | 38929篇 |
2006年 | 44080篇 |
2005年 | 36869篇 |
2004年 | 37964篇 |
2003年 | 35550篇 |
2002年 | 36327篇 |
2001年 | 36076篇 |
2000年 | 31748篇 |
1999年 | 29045篇 |
1998年 | 27528篇 |
1997年 | 27402篇 |
1996年 | 26910篇 |
1995年 | 24686篇 |
1994年 | 24177篇 |
1993年 | 23536篇 |
1992年 | 23379篇 |
1991年 | 23547篇 |
1990年 | 22357篇 |
1989年 | 21976篇 |
1988年 | 21142篇 |
1987年 | 19908篇 |
1986年 | 18739篇 |
1985年 | 25258篇 |
1984年 | 26396篇 |
1983年 | 22329篇 |
1982年 | 23708篇 |
1981年 | 22895篇 |
1980年 | 22165篇 |
1979年 | 22094篇 |
1978年 | 23314篇 |
1977年 | 22886篇 |
1976年 | 22474篇 |
1975年 | 21118篇 |
1974年 | 20740篇 |
1973年 | 21236篇 |
1972年 | 15404篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
241.
Dr. Liat Avram Dr. Václav Havel Ronit Shusterman-Krush Dr. Mark A. Iron Dr. Moritz Zaiss Prof. Vladimír Šindelář Dr. Amnon Bar-Shir 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(7):1687-1690
The accumulated knowledge regarding molecular architectures is based on established, reliable, and accessible analytical tools that provide robust structural and functional information on assemblies. However, both the dynamicity and low population of noncovalently interacting moieties within studied molecular systems limit the efficiency and accuracy of traditional methods. Herein, the use of a saturation transfer-based NMR approach to study the dynamic binding characteristics of an anion to a series of synthetic receptors derived from bambusuril macrocycles is demonstrated. The exchange rates of BF4− are mediated by the side chains on the receptor (100 s−1<kex<5000 s−1), which play a critical role in receptor-anion binding dynamics. The signal amplification obtained with this approach allows for the identification of different types of intermolecular interactions between the receptor and the anion, something that could not have been detected by techniques hitherto used to study molecular assemblies. These findings, which are supported by a computational molecular dynamic study, demonstrate the uniqueness and added value of this NMR method. 相似文献
242.
Jasmin Kuhn Philipp M. Klein Nader Al Danaf Joel Z. Nordin Sren Reinhard Dominik M. Loy Miriam Hhn Samir El Andaloussi Don C. Lamb Ernst Wagner Yoshitsugu Aoki Taavi Lehto Ulrich Lchelt 《Advanced functional materials》2019,29(48)
Phosphorodiamidate morpholino oligomers (PMOs) are oligonucleotide analogs that can be used for therapeutic modulation of pre‐mRNA splicing. Similar to other classes of nucleic acid‐based therapeutics, PMOs require delivery systems for efficient transport to the intracellular target sites. Here, artificial peptides based on the oligo(ethylenamino) acid succinyl‐tetraethylenpentamine (Stp), hydrophobic modifications, and an azide group are presented, which are used for strain‐promoted azide‐alkyne cycloaddition conjugation with splice‐switching PMOs. By systematically varying the lead structure and formulation, it is determined that the type of contained fatty acid and supramolecular assembly have a critical impact on the delivery efficacy. A compound containing linolenic acid with three cis double bonds exhibits the highest splice‐switching activity and significantly increases functional protein expression in pLuc/705 reporter cells in vitro and after local administration in vivo. Structural and mechanistic studies reveal that the lipopeptide PMO conjugates form nanoparticles, which accelerate cellular uptake and that the content of unsaturated fatty acids enhances endosomal escape. In an in vitro Duchenne muscular dystrophy exon skipping model using H2K‐mdx52 dystrophic skeletal myotubes, the highly potent PMO conjugates mediate significant splice‐switching at very low nanomolar concentrations. The presented aminoethylene‐lipopeptides are thus a promising platform for the generation of PMO‐therapeutics with a favorable activity/toxicity profile. 相似文献
243.
244.
245.
246.
247.
248.
249.
250.