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21.
K. V. Solovyov N. A. Grudinina E. N. Semernin I. V. Morozova S. A. Smirnova D. S. Polyakov T. D. Aleynikova E. V. Shliakhto A. Ya. Gudkova M. M. Shavlovsky 《Russian Journal of Genetics》2011,47(4):477-482
A search of transthyretin (TTR) gene mutations was performed in patients with cardiomyopathies from St. Petersburg. Mutations H90N, V30M and deletion (del9)
of nucleotides GACTTCTCC in position 6776 from the start codon of the TTR gene (in position 98782 according to reference sequence AC079096 (NCBI) was found. The H90N mutation in the third exon of
TTR gene was detected in a son of a cardiomyopathy patient and in his mother, which lacked any clinical manifestations. Mutation
V30M in exon 2 of TTR gene was found in heterozygous in one of the probands. Deletion (del9) was revealed in a patient with cardiomyopathy and
in his two daughters from different marriages, who had no clinical manifestations of the disease. All the mutations revealed
in this study were previously identified in other populations. 相似文献
22.
Conditions that influence the luminescence of natural and recombinant luminescent bacteria in the presence of blood serum were studied. In general, blood serum quenched the luminescence of the marine Photobacterium phosphoreum and the recombinant Escherichia coli strains harboring the luminescent system genes of Photobacterium leiognathi, but enhanced the luminescence of the soil bacterium Photorhabdus luminescens Zm1 and the recombinant E. coli strain harboring the lux operon of P. luminescens Zm1. The quenching effect of blood serum increased with its concentration and the time and temperature of incubation. The components of blood serum that determine the degree and specificity of its action on bacterial luminescence were identified.__________Translated from Mikrobiologiya, Vol. 74, No. 2, 2005, pp. 191–197.Original Russian Text Copyright © 2005 by Deryabin, Polyakov. 相似文献
23.
Ilya V. Demidyuk Tania Yu. Gromova Konstantin M. Polyakov William R. Melik-Adamyan Inna P. Kuranova Sergey V. Kostrov 《The Journal of biological chemistry》2010,285(3):2003-2013
Protealysin (PLN) belongs to the M4 family of peptidases that are commonly known as thermolysin-like proteases (TLPs). All TLPs are synthesized as precursors containing N-terminal propeptides. According to the primary structure of the N-terminal propeptides, the family is divided into two distinct groups. Representatives of the first group including thermolysin and all TLPs with known three-dimensional structures have long prosequences (∼200 amino acids). Enzymes of the second group, whose prototype is protealysin, have short (∼50 amino acids) propeptides. Here, we present the 1.8 Å crystal structure of PLN precursor (proPLN), which is the first three-dimensional structure of a TLP precursor. Whereas the structure of the catalytic domain of proPLN is similar overall to previously reported structures of mature TLPs, it has specific features, including the absence of calcium-binding sites, and different structures of the N-terminal region and substrate-binding site. PLN propeptide forms a separate domain in the precursor and likely acts as an inhibitor that blocks the substrate-binding site and fixes the “open” conformation of the active site, which is unfavorable for catalysis. Furthermore the conserved PPL motif identified in our previous studies directly interacts with the S′ subsites of the active center being a critical element of the propeptide-catalytic domain interface. Comparison of the primary structures of TLPs with short propeptides suggests that the specific features revealed in the proPLN crystal structure are typical for all protealysin-like enzymes. Thus, such proteins can be considered as a separate subfamily of TLPs. 相似文献
24.
T. V. Fedorova A. M. Chulkin E. A. Vavilova I. G. Maisuradze A. A. Trofimov I. N. Zorov V. P. Khotchenkov K. M. Polyakov S. V. Benevolensky O. V. Koroleva V. S. Lamzin 《Biochemistry. Biokhimii?a》2012,77(10):1190-1198
The gene xylE encoding endo-1,4-β-xylanase from the 10th family of glycosyl hydrolases produced by the mycelial fungus Penicillium canescens has been expressed under the control of the strong promoter of the bgaS gene encoding β-galactosidase from P. canescens. As a result, a strain-producer of endoxylanase XylE was developed. The recombinant enzyme was isolated and purified to homogeneity with specific activity of 50 U/mg. The physicochemical and biochemical properties of the endoxylanase were studied. The maximal enzymatic activity was observed at pH 6.0 and 70°C. Endoxylanase XylE was shown to be a highly thermostable enzyme with half-inactivation period τ1/2 of 7 h at 60°C. The kinetic parameters were 0.52 mg/ml (K m) and 75 μmol/min per mg (V max) using birch xylan as the substrate. Crystals of endoxylonase XylE were obtained, and the 3D structure was solved at 1.47 ? resolution. The 3D structure of an endo-1,4-β-xylanase from the 10th family containing carbohydrate and unique cyclic structure located at the C-terminus of the polypeptide chain was obtained for the first time. 相似文献
25.
N. M. Galeeva S. A. Nenasheva I. S. Kleymenova A. V. Polyakov 《Russian Journal of Genetics》2012,48(11):1148-1157
Hereditary types I and II methemoglobinemia is a rare autosomal recessive disease due to a deficiency of either soluble or soluble and membrane-bound forms of the enzyme NADH-cytochrome b5 reductase. The molecular genetic bases of both types of the disease consist in changes in the CYB5R3 gene. In this study, the novel and, to date, only large deletion in this gene is described, discovered in two unrelated families with types I and II methemoglobinemia. The common founder haplotype on the chromosomes carrying this mutation was identified. A universal approach for searching for the deletion boundaries was developed, and the c.22-1320_633+1224del deletion breakpoints were determined. In addition, a system for identifying the deletion in heterozygous and homozygous states was designed. 相似文献
26.
E. A. Arifulin E. E. Bragina V. A. Zamyatnina E. G. Volkova E. V. Sheval’ S. A. Golyshev L. N. Kintsurashvili G. I. Kir’yanov A. N. Prusov V. Yu. Polyakov 《Russian Journal of Developmental Biology》2012,43(2):121-130
Changes in chromatin structure at different stages of differentiation of human spermatids were studied. It was shown that,
in nuclei of early spermatids, chromatin is loosely packed and its structural element is an 8-nm fiber. This “elementary”
fiber is predominant at the initial stages of differentiation; in the course of maturation, it is replaced by globular elements
approximately 60 nm in diameter. In intermediate spermatids, these globules start to condense into fibrillar aggregates and
reduce their diameter to 30–40 nm. At all stages of spermatid maturation, except the final stages, these globules are convergence
centers for elementary fibers. This remodelling process is vectored and directed from the apical (acrosomal) to the basal
pole of the nucleus. In mature spermatids, the elementary 8-nm fibers are almost absent and the major components are 40-nm
fibrillar aggregates. The nuclei of mature spermatids are structurally identical with the nuclei of spermatozoa with the so-called
“immature chromatin,” which are commonly found in a low proportion in sperm samples from healthy donors and may prevail over
the normal cells in spermiogenetic disorders. The cause of this differentiation blockade remains unknown. Possibly, the formation
of intermolecular bonds between protamines, which are required for the final stages of chromatin condensation, is blocked
in a part of spermatids. The results of this study are discussed in comparison with the known models of nucleoprotamine chromatin
organization in human spermatozoa. 相似文献
27.
28.
V. A. Vavilin N. F. Salakhutdinov Yu. I. Ragino N. E. Polyakov M. B. Taraban T. V. Leshina E. M. Stakhneva V. V. Lyakhovich Yu. P. Nikitin G. A. Tolstikov 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2008,2(4):373-380
A molecular complex of simvastatin (SV) and glycyrrhizic acid (GA) (at their ratio of 1 : 4) has been synthesized. The complex named “simvaglyzin” (SVG) was stable in aqueous and aqueous-alcohol solutions at GA concentrations exceeding 0.2 mM. In vitro SVG acted as an uncompetitive inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA (3-HMG-CoA) reductase (Ki of 94 nM). Appearance of this inhibitory activity is associated with cytochrome P450-dependent conversion of SVG, because the addition of 1 mM metyrapone to the incubation medium fully prevented the inhibition of 3-HMG-CoA reductase. SV and SVG (used at 300 nM concentration) inhibited mevalonate synthesis rate by 39.15±8,27 and 38.85±3,04%, respectively. In vivo SVG showed a dose-dependent cholesterol lowering effect. In rats the cholesterol lowering effect of SVG used at daily doses equivalent to 66 and 100 mg/kg of SV was the same as the effect of SV administered at the daily dose of 200 mg/kg. The decrease in total cholesterol of blood serum was 7% and 9% (p < 0.05) and 8%, respectively. Myotoxicity of these SVG doses estimated by blood serum creatine phosphokinase (CPK) activity was lower than that of SV. In rats treated with SV the activity of CPK increased by 79% (p < 0.01), while in SVG treated rats it decreased by 30% and 36% (p < 0.05). Any increase of the hepatotoxicity markers alanine aminotransferase or aspartate aminotransferase in blood serum was not observed. The data suggest pharmacological synergism attributed to the SV-GA complex formation and increased safety of the resultant complex compared with a parent compound. 相似文献
29.
Kordyukova LV Serebryakova MV Polyakov VY Ovchinnikova TV Smirnova YA Fedorova NV Baratova LA 《Protein and peptide letters》2008,15(9):922-930
Influenza A virus matrix M1 protein is membrane associated and plays a crucial role in virus assembly and budding. The N-terminal two thirds of M1 protein was resolved by X-ray crystallography. The overall 3D structure as well as arrangement of the molecule in relation to the viral membrane remains obscure. Now a proteolytic digestion of virions with bromelain was used as an instrument for the in situ assessment of the M1 protein structure. The lipid bilayer around the subviral particles lacking glycoprotein spikes was partially disrupted as was shown by transmission electron microscopy. A phenomenon of M1 protein fragmentation inside the subviral particles was revealed by SDS-PAGE analysis followed by in-gel trypsin hydrolysis and MALDI-TOF mass spectrometry analysis of the additional bands. Putative bromelain-digestion sites appeared to be located at the surface of the M1 protein globule and could be used as landmarks for 3D molecular modeling. 相似文献
30.
A. V. Polyakov 《Plasma Physics Reports》2004,30(7):605-615
The acceleration of solar-wind protons in a current sheet in the Earth's magnetotail, in which the geomagnetic field lines
reconnect, is investigated numerically using the dynamic current sheet model proposed by S.I. Syrovatski
$\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{
. The dynamics of current sheets in the Earth's magnetotail is analyzed. In addition to the known solutions, the solution
describing a contracting current sheet is derived. The time evolution of the magnetic field structure in Syrovatski
$\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{
's model is calculated numerically. The energy spectrum of the protons that are accelerated in the sheet by induction electric
fields during rapid changes in the sheet topology is calculated and analyzed. A study is made of proton acceleration up to
the time when the current sheet ruptures in the course of its evolution. 相似文献