全文获取类型
收费全文 | 480篇 |
免费 | 43篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 14篇 |
2020年 | 5篇 |
2019年 | 11篇 |
2018年 | 19篇 |
2017年 | 16篇 |
2016年 | 19篇 |
2015年 | 26篇 |
2014年 | 23篇 |
2013年 | 31篇 |
2012年 | 46篇 |
2011年 | 41篇 |
2010年 | 32篇 |
2009年 | 23篇 |
2008年 | 20篇 |
2007年 | 37篇 |
2006年 | 21篇 |
2005年 | 22篇 |
2004年 | 22篇 |
2003年 | 20篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有523条查询结果,搜索用时 46 毫秒
511.
512.
Volker Presser Lifeng Zhang Jun Jie Niu John McDonough Carlos Perez Hao Fong Yury Gogotsi 《Liver Transplantation》2011,1(3):423-430
Nano‐fibrous felts (nano‐felts) of carbide‐derived carbon (CDC) have been developed from the precursor of electrospun titanium carbide (TiC) nano‐felts. Conformal transformation of TiC into CDC conserves main features of the precursor including the high interconnectivity and structural integrity; the developed TiC‐CDC nano‐felts are mechanically flexible/resilient, and can be used as electrode material for supercapacitor application without the addition of any binder. After synthesis through chlorination of the precursor at 600 °C, the TiC‐CDC nano‐fibers show an average pore size of ~1nm, a high specific surface area of 1390 m2/g; and the nano‐fibers have graphitic carbon ribbons embedded in a highly disordered carbon matrix. Graphitic carbon is preserved from the precursor nano‐fibers where a few graphene layers surround TiC nanocrystallites. Electrochemical measurements show a high gravimetric capacitance of 110 F/g in aqueous electrolyte (1 M H2SO4) and 65 F/g in organic electrolyte (1.5 M TEA‐BF4 in acetonitrile). Because of the unique microstructure of TiC‐CDC nano‐felts, a fade of the capacitance of merely 50% at a high scan rate of 5 V/s is observed. A fade of just 15% is observed for nano‐felt film electrodes tested in 1 M H2 SO4 at 1 V/s, resulting in a high gravimetric capacitance of 94 F/g. Such a high rate performance is only known for graphene or carbon‐onion based supercapacitors, whereas binders have to be used for the fabrication of those supercapacitors. 相似文献
513.
514.
The glucosyltransferase Lgt1 is one of three glucosylating toxins of Legionella pneumophila, the causative agent of Legionnaires disease. It acts through specific glucosylation of a serine residue (S53) in the eukaryotic elongation factor 1A and belongs to type A glycosyltransferases. High-resolution crystal structures of Lgt1 show an elongated shape of the protein, with the binding site for uridine disphosphate glucose at the bottom of a deep cleft. Lgt1 shows only a low sequence identity with other type A glycosyltransferases, and structural conservation is limited to a central folding core that is usually observed within this family of proteins. Domains and protrusions added to the core motif represent determinants for the specific recognition and binding of the target. Manual docking experiments based on the crystal structures of toxin and target protein suggest an obvious mode of binding to the target that allows for efficient transfer of a glucose moiety. 相似文献
515.
516.
Andrey G. Tereshchenkov Malgorzata Dobosz-Bartoszek Ilya A. Osterman James Marks Vasilina A. Sergeeva Pavel Kasatsky Ekaterina S. Komarova Andrey N. Stavrianidi Igor A. Rodin Andrey L. Konevega Petr V. Sergiev Natalia V. Sumbatyan Alexander S. Mankin Alexey A. Bogdanov Yury S. Polikanov 《Journal of molecular biology》2018,430(6):842-852
Antibiotic chloramphenicol (CHL) binds with a moderate affinity at the peptidyl transferase center of the bacterial ribosome and inhibits peptide bond formation. As an approach for modifying and potentially improving properties of this inhibitor, we explored ribosome binding and inhibitory activity of a number of amino acid analogs of CHL. The L-histidyl analog binds to the ribosome with the affinity exceeding that of CHL by 10 fold. Several of the newly synthesized analogs were able to inhibit protein synthesis and exhibited the mode of action that was distinct from the action of CHL. However, the inhibitory properties of the semi-synthetic CHL analogs did not correlate with their affinity and in general, the amino acid analogs of CHL were less active inhibitors of translation in comparison with the original antibiotic. The X-ray crystal structures of the Thermus thermophilus 70S ribosome in complex with three semi-synthetic analogs showed that CHL derivatives bind at the peptidyl transferase center, where the aminoacyl moiety of the tested compounds established idiosyncratic interactions with rRNA. Although still fairly inefficient inhibitors of translation, the synthesized compounds represent promising chemical scaffolds that target the peptidyl transferase center of the ribosome and potentially are suitable for further exploration. 相似文献
517.
Yury B. Yurov 《Journal of molecular biology》1980,136(3):339-342
Autoradiography of replicating DNA molecules isolated from individual human cells shows that the rate of DNA replication fork movement within a single cell varies from 0.2 to 1.2 μm/min with an average value of 0.5 to 0.6 μm/min. These data suggest that replication forks move at substantially different rates in different parts of the genome within a single cell. 相似文献
518.
Elena V. Artyukova Marina M. Kozyrenko Peter G. Gorovoy Yury N. Zhuravlev 《Genetica》2009,137(2):201-212
Microbiota decussata Kom. (Cupressaceae) is a subalpine species endemic to the Sikhote Alin Mountains with populations scattered throughout the
range. We used sequence data for four noncoding regions of chloroplast DNA to characterize the genetic diversity in populations
sampled from different parts of M. decussata natural range. No variation was observed in the trnT–trnF region, whereas the trnH–psbA, trnS–trnfM, and trnS–trnG regions showed polymorphisms. At the species level, we found a low nucleotide diversity (π = 0.0009) and high haplotype diversity
(h = 0.981) as well as high differentiation (ΦST = 0.420). N
ST and G
ST values suggested the existence of a phylogeographic structure in M. decussata. The observed patterns of diversity could be explained in part by ecological features of the species and its long-term persistence
throughout the range with population expansion, successive fragmentation and isolation. 相似文献
519.
520.
Dmitry Kaluzhny Anna ShchyolkinaMichael Livshits Yury LysovOlga Borisova 《Biophysical chemistry》2009
Human genome is shown to be enriched with (GT)n stretches of lengths from 8 to 20 dinucleotides. Low temperature (T ≤ 10 °C) conformations of d(GT)n oligonucleotides (n = 7, 8, 12, 16, 20) were studied by means of circular dichroism (CD), thermal melting, ethidium bromide (EtBr) probing and single nucleotide substitutions. Rotational relaxation times for EtBr:d(GT)n complexes confirmed a monomolecular state of the oligonucleotides. CD spectra indicated involvement of all guanines of d(GT)8 and d(GT)16 in G-quartets, while dT(GT)7, d(GT)12 and d(GT)20 were shown to be only partially ordered. The schemes of the d(GT)8 and d(GT)16 folds are suggested. 相似文献