全文获取类型
收费全文 | 198篇 |
免费 | 0篇 |
专业分类
198篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 1篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 11篇 |
2002年 | 13篇 |
2001年 | 12篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1972年 | 7篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1968年 | 3篇 |
1967年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有198条查询结果,搜索用时 15 毫秒
11.
A. A. Dobrovol’skaya G. B. Rodionova A. S. Voronkov L. V. Kovaleva 《Russian Journal of Plant Physiology》2009,56(3):394-401
Sporophyte-gametophyte interactions between anther and male gametophyte were investigated in two (fertile and sterile) clones of petunia (Petunia hybrida L.) with different reproductive strategies. Structural and functional reorganization of sporophyte tissues in the developing anther of fertile clone is closely coordinated with each of the successive stages of male gametophyte development (from meiosis to the formation of binuclear pollen) and comprises not only destruction of tapetum and three middle layers of the wall but also an activation of gas exchange and a rise in the content of sugars (sucrose, fructose, and glucose). In sterile clone, degradation of tapetum and anomalies in the development of sporogenic tissue were simultaneously observed in the prophase of meiosis. The death of microsporocytes and degeneration of tapetum were accompanied by a decrease in the level of sucrose delivered to the anther tissues and changes in the ratio between sucrose and hexoses in favor of glucose. 相似文献
12.
A novel peptide recognition mode revealed by the X-ray structure of a core U2AF35/U2AF65 heterodimer
U2 auxiliary factor (U2AF) is an essential splicing factor that recognizes the 3' splice site and recruits the U2 snRNP to the branch point. The X-ray structure of the human core U2AF heterodimer, consisting of the U2AF35 central domain and a proline-rich region of U2AF65, has been determined at 2.2 A resolution. The structure reveals a novel protein-protein recognition strategy, in which an atypical RNA recognition motif (RRM) of U2AF35 and the U2AF65 polyproline segment interact via reciprocal "tongue-in-groove" tryptophan residues. Complementary biochemical experiments demonstrate that the core U2AF heterodimer binds RNA, and that the interacting tryptophan side chains are essential for U2AF dimerization. Atypical RRMs in other splicing factors may serve as protein-protein interaction motifs elsewhere during spliceosome assembly. 相似文献
13.
N. N. Rodionova E. Z. Bibineyshvili A. R. Brazhe A. I. Yusipovich G. V. Maksimov A. B. Rubin 《Biophysics》2014,59(1):83-85
Using Raman spectrometry and fluorescence microscopy, we studied the rearrangement of carotenoid molecules and membrane-bound Ca mb 2+ in myelinated nerve fibers after K+ depolarization, K+-channel blocking, and altering the membrane protein conformation. We observed a decrease in Ca mb 2+ and an increase of microviscosity in myelin after depolarization. Changes in Ca mb 2+ and microviscosity were registered after blocking the K+ channels and modifying proteins with PCMB. Our results suggest an interconnection between the condition of nerve fiber membrane proteins, Ca mb 2+ distribution, and myelin microviscosity. 相似文献
14.
We studied the effect of the peppermint ambient odor on the performance of routine Russian school language tests by primary-school students in a standard classroom, where a noiseless source of odor provided scenting the air by means of free evaporation of the essential oil at a constant low concentration. It is shown that in the presence of peppermint odor the marks for a word dictation test that is based on the longterm memory are significantly higher than in the absence of the odor, whereas the performance of text copying test (based mainly on attention) is not influenced by the presence of peppermint odor. 相似文献
15.
A. M. Polyanichko T. J. Rodionova V. I. Vorob’ev E. V. Chikhirzhina 《Cell and Tissue Biology》2011,5(2):114-119
Changes in secondary structure of DNA and non-histone chromosomal protein HMGB1 during the formation of the complex have been
studied by circular dichroism and UV spectroscopy. It was demonstrated that the HMGB1 protein is able to change its secondary
structure upon binding to DNA. Based on the assumption that there are two spectroscopically distinguishable forms of the HMGB1
in solution, we estimated the fraction of bound protein. The fraction of bound protein decreases at higher protein to DNA
ratios r from 0.48 at r = 0.13 to 0.06 at r = 2.43. It was shown that HMGB1 is able to induce considerable changes in DNA structure, even when the amount of protein
actually bound is low. 相似文献
16.
Irina A. Rodionova David A. Scott Nick V. Grishin Andrei L. Osterman Dmitry A. Rodionov 《Environmental microbiology》2012,14(11):2920-2934
Thermotoga maritima is a marine hyperthermophilic microorganism that degrades a wide range of simple and complex carbohydrates including pectin and produces fermentative hydrogen at high yield. Galacturonate and glucuronate, two abundant hexuronic acids in pectin and xylan, respectively, are catabolized via committed metabolic pathways to supply carbon and energy for a variety of microorganisms. By a combination of bioinformatics and experimental techniques we identified a novel enzyme family (named UxaE) catalysing a previously unknown reaction in the hexuronic acid catabolic pathway, epimerization of tagaturonate to fructuronate. The enzymatic activity of the purified recombinant tagaturonate epimerase from T. maritima was directly confirmed and kinetically characterized. Its function was also confirmed by genetic complementation of the growth of the Escherichia coli uxaB knockout mutant strain on galacturonate. An inferred novel galacturonate to mannonate catabolic pathway in T. maritima was reconstituted in vitro using a mixture of recombinant purified enzymes UxaE, UxaC and UxuB. Members of the newly identified UxaE family were identified in ~ 50 phylogenetically diverse heterotrophic bacteria from aquatic and soil environments. The genomic context of respective genes and reconstruction of associated pathways suggest that UxaE enzymatic and biological function remains conserved in all of these species. 相似文献
17.
Lukashina E Ksenofontov A Fedorova N Badun G Mukhamedzhanova A Karpova O Rodionova N Baratova L Dobrov E 《Molecular Plant Pathology》2012,13(1):38-45
Previously, we have reported that intact Potato virus X (PVX) virions cannot be translated in cell-free systems, but acquire this capacity by the binding of PVX-specific triple gene block protein 1 (TGBp1) or after phosphorylation of the exposed N-terminal segment of intravirus coat protein (CP) by protein kinases. With the help of in vitro mutagenesis, a nonphosphorylatable PVX mutant (denoted ST PVX) was prepared in which all 12 S and T residues in the 20-residue-long N-terminal CP segment were substituted by A or G. Contrary to expectations, ST PVX was infectious, produced normal progeny and was translated in vitro in the absence of any additional factors. We suggest that the N-terminal PVX CP segment somehow participates in virion assembly in vivo and that CP subunits in ST virions may differ in structure from those in the wild-type (UK3 strain). In the present work, to test this suggestion, we performed a comparative tritium planigraphy study of CP structure in UK3 and ST virions. It was found that the profile of tritium incorporation into ST mutant virions in some CP segments differed from that of normal UK3 virions and from UK3 complexed with the PVX movement protein TGBp1. It is proposed that amino acid substitutions in ST CP and the TGBp1-driven remodelling of UK3 virions induce structural alterations in intravirus CPs. These alterations affect the predicted RNA recognition motif of PVX CP, but in different ways: for ST PVX, labelling is increased in α-helices 6 and 7, whereas, in remodelled UK3, labelling is increased in the β-sheet strands β3, β4 and β5. 相似文献
18.
E. U. Poluektova E. Yu. Gagarina I. P. Shilovskii E. A. Fedorina V. Z. Nezametdinova S. A. Rodionova A. A. Prozorov 《Russian Journal of Genetics》2008,44(5):539-545
Two fragments of conjugative plasmid p19 (95 kb) from the Bacillus subtilis 19 soil strain were cloned and sequenced; these fragments carry genes, products of which are indispensable for the conjugative transfer. One of the fragments 4518 bp in size carries five open reading frames and their fragments (ORF1–ORF5). The protein corresponding to ORF4 is homologous to proteins from the family VirD4. Inactivation of ORF4 and ORF1 by insertional mutagenesis caused a three-to-fivefold decrease in the frequency of plasmid p19 conjugative transfer. Another 2932-bp fragment of p19 was shown to possess a rep region homologous to the rep region of plasmid pBS72 from the B. subtilis 72 soil strain and a novel ORF (ORF6); the protein corresponding to this ORF contains the HTH motif typical for DNA-binding proteins. 相似文献
19.
20.
Lyudmila A Baratova Nataliya V Fedorova Eugenie N Dobrov Elena V Lukashina Andrey N Kharlanov Vitaly V Nasonov Marina V Serebryakova Stanislav V Kozlovsky Olga V Zayakina Nina P Rodionova 《European journal of biochemistry》2004,271(15):3136-3145
The primary structures of N-terminal 19-mer peptides, released by limited trypsin treatment of coat protein (CP) subunits in intact virions of three potato virus X (PVX) isolates, were analyzed. Two wild-type PVX strains, Russian (Ru) and British (UK3), were used and also the ST mutant of UK3 in which all 12 serine and threonine residues in the CP N-terminal segment were replaced by glycine or alanine. With the help of direct carbohydrate analysis and MS, it was found that the acetylated N-terminal peptides of both wild-type strains are glycosylated by a single monosaccharide residue (galactose or fucose) at NAcSer in the first position of the CP sequence, whereas the acetylated N-terminal segment of the ST mutant CP is unglycosylated. Fourier transform infrared spectra in the 1000-4000 cm(-1) region were measured for films of the intact and in situ trypsin-degraded PVX preparations at low and high humidity. These spectra revealed the presence of a broad-band in the region of valent vibrations of OH bonds (3100-3700 cm(-1)), which can be represented by superposition of three bands corresponding to tightly bound, weakly bound, and free OH groups. On calculating difference ('wet' minus 'dry') spectra, it was found that the intact wild-type PVX virions are characterized by high water-absorbing capacity and the ability to order a large number of water molecules on the virus particle. This effect was much weaker for the ST mutant and completely absent in the trypsin-treated PVX. It is proposed that the surface-located and glycosylated N-terminal CP segments of intact PVX virions induce the formation of a columnar-type shell from bound water molecules around the virions, which probably play a major role in maintaining the virion surface structure. 相似文献