全文获取类型
收费全文 | 297篇 |
免费 | 26篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 16篇 |
2014年 | 18篇 |
2013年 | 18篇 |
2012年 | 20篇 |
2011年 | 22篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 13篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1990年 | 6篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 1篇 |
1972年 | 6篇 |
1970年 | 1篇 |
1968年 | 3篇 |
1967年 | 2篇 |
1965年 | 1篇 |
1961年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有323条查询结果,搜索用时 400 毫秒
71.
72.
Dawid Lewandowski Marta Lewandowska Piotr Ruszkowski Anita Pińska Grzegorz Schroeder 《PloS one》2015,10(5)
Novel zidovudine derivatives, able to be covalently conjugated to silica surface, have been obtained and grafted to SBA-15 mesoporous silica. Cytotoxic activity of the hybrid organic-inorganic (zidovudine derivatives-silica) systems against HeLa and KB cell lines has been analyzed. Addition of folic acid had a positive influence on the cytotoxicity. Up to 69% of HeLa and 65% of KB tumor cells growth inhibition has been achieved at low silica concentration used (10 μg/mL). 相似文献
73.
I B Dawid 《Journal of molecular biology》1972,63(2):201-216
74.
We have performed the molecular dynamics simulations for the free cholesterol cluster and the same cluster located near the carbon nanotube. We have found that the cholesterol molecules quite evenly cover the surface of single walled armchair (10, 10) carbon nanotube, forming the molecular layer. Moreover, the characteristic alignment of cholesterol molecules within the layer (along the nanotube) is observed. The comparison of the structural and dynamical observable characterizing cholesterol molecule is presented and discussed, both for the cluster with and without the presence of the nanotube. 相似文献
75.
Roksana Wałęsa Dariusz Man Grzegorz Engel Dawid Siodłak Teobald Kupka Tomasz Ptak Małgorzata A. Broda 《化学与生物多样性》2015,12(7):1007-1024
Electron spin resonance (ESR), 1H‐NMR, voltage and resistance experiments were performed to explore structural and dynamic changes of Egg Yolk Lecithin (EYL) bilayer upon addition of model peptides. Two of them are phenylalanine (Phe) derivatives, Ac‐Phe‐NHMe ( 1 ) and Ac‐Phe‐NMe2 ( 2 ), and the third one, Ac‐(Z)‐ΔPhe‐NMe2 ( 3 ), is a derivative of (Z)‐α,β‐dehydrophenylalanine. The ESR results revealed that all compounds reduced the fluidity of liposome's membrane, and the highest activity was observed for compound 2 with N‐methylated C‐terminal amide bond (Ac‐Phe‐NMe2). This compound, being the most hydrophobic, penetrates easily through biological membranes. This was also observed in voltage and resistance studies. 1H‐NMR studies provided a sound evidence on H‐bond interactions between the studied diamides and lecithin polar head. The most significant changes in H‐atom chemical shifts and spin‐lattice relaxation times T1 were observed for compound 1 . Our experimental studies were supported by theoretical calculations. Complexes EYL? Ac‐Phe‐NMe2 and EYL? Ac‐(Z)‐ΔPhe‐NMe2, stabilized by NH???O or/and CH???O H‐bonds were created and optimized at M06‐2X/6‐31G(d) level of theory in vacuo and in H2O environment. According to our molecular‐modeling studies, the most probable lecithin site of H‐bond interaction with studied diamides is the negatively charged O‐atom in phosphate group which acts as H‐atom acceptor. Moreover, the highest binding energy to hydrocarbon chains were observed in the case of Ac‐Phe‐NMe2 ( 2 ). 相似文献
76.
Lionnet T Dawid A Bigot S Barre FX Saleh OA Heslot F Allemand JF Bensimon D Croquette V 《Nucleic acids research》2006,34(15):4232-4244
Helicases and translocases are proteins that use the energy derived from ATP hydrolysis to move along or pump nucleic acid substrates. Single molecule manipulation has proved to be a powerful tool to investigate the mechanochemistry of these motors. Here we first describe the basic mechanical properties of DNA unraveled by single molecule manipulation techniques. Then we demonstrate how the knowledge of these properties has been used to design single molecule assays to address the enzymatic mechanisms of different translocases. We report on four single molecule manipulation systems addressing the mechanism of different helicases using specifically designed DNA substrates: UvrD enzyme activity detection on a stretched nicked DNA molecule, HCV NS3 helicase unwinding of a RNA hairpin under tension, the observation of RecBCD helicase/nuclease forward and backward motion, and T7 gp4 helicase mediated opening of a synthetic DNA replication fork. We then discuss experiments on two dsDNA translocases: the RuvAB motor studied on its natural substrate, the Holliday junction, and the chromosome-segregation motor FtsK, showing its unusual coupling to DNA supercoiling. 相似文献
77.
Krokowski D Boguszewska A Abramczyk D Liljas A Tchórzewski M Grankowski N 《Molecular microbiology》2006,60(2):386-400
The ribosome has a distinct lateral protuberance called the stalk; in eukaryotes it is formed by the acidic ribosomal P-proteins which are organized as a pentameric entity described as P0-(P1-P2)(2). Bilateral interactions between P0 and P1/P2 proteins have been studied extensively, however, the region on P0 responsible for the binding of P1/P2 proteins has not been precisely defined. Here we report a study which takes the current knowledge of the P0 - P1/P2 protein interaction beyond the recently published information. Using truncated forms of P0 protein and several in vitro and in vivo approaches, we have defined the region between positions 199 and 258 as the P0 protein fragment responsible for the binding of P1/P2 proteins in the yeast Saccharomyces cerevisiae. We show two short amino acid regions of P0 protein located at positions 199-230 and 231-258, to be responsible for independent binding of two dimers, P1A-P2B and P1B-P2A respectively. In addition, two elements, the sequence spanning amino acids 199-230 and the P1A-P2B dimer were found to be essential for stalk formation, indicating that this process is dependent on a balance between the P1A-P2B dimer and the P0 protein. 相似文献
78.
79.
Małgorzata A. Broda Aneta Buczek Dawid Siodłak Barbara Rzeszotarska 《Journal of peptide science》2009,15(7):465-473
Dehydroamino acids are non‐coded amino acids that offer unique conformational properties. Dehydrophenylalanine (ΔPhe) is most commonly used to modify bioactive peptides to constrain the topography of the phenyl ring in the side chain, which commonly serves as a pharmacophore. The Ramachandran maps (in the gas phase and in CHCl3 mimicking environments) of ΔPhe analogues with methyl groups at the β position of the side chain as well as at the C‐terminal amide were calculated using the B3LYP/6‐31 + G** method. Unexpectedly, β‐methylation alone results in an increase of conformational freedom of the affected ΔPhe residue. However, further modification by introducing an additional methyl group at C‐terminal methyl amide results in a steric crowding that fixes the torsion angle ψ of all conformers to the value 123°, regardless of the Z or E position of the phenyl ring. The number of conformers is reduced and the accessible conformational space of the residues is very limited. In particular, (Z)‐Δ(βMe)Phe with the tertiary C‐terminal amide can be classified as the amino acid derivative that has a single conformational state as it seems to adopt only the β conformation. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
80.
Hsp90 chaperones wild-type p53 tumor suppressor protein 总被引:6,自引:0,他引:6
Walerych D Kudla G Gutkowska M Wawrzynow B Muller L King FW Helwak A Boros J Zylicz A Zylicz M 《The Journal of biological chemistry》2004,279(47):48836-48845