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排序方式: 共有318条查询结果,搜索用时 15 毫秒
1.
A number of motile strains of Azospirillum brasilense, A. lipoferum, and A. irakense, were found to possess tyrosinase activity both on the surface of and inside the cells. A. brasilense Sp245, Sp7, and A. irakense KBC-1 each possessed two forms of tyrosinase of different molecular masses; A. lipoferum 43, A. lipoferum 59b, and A. irakense KA-3 each had a single tyrosinase form of approximately the same molecular mass; and A. brasilense Sp107 possessed a single form of tyrosinase different from all the other forms. 相似文献
2.
A M Sukhorukov A M Ponomareva 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1987,(9):18-22
The capacity of polystyrene carriers used in the enzyme immunoassay (EIA) for adsorbing 131I-labeled human serum albumin under different conditions has been studied, and the comparison of the plates manufactured by Dynatech AG (Switzerland) and by the Leningrad Works of Medical Polymers has been made. At the first stages of the reaction the antigen is separated from the carrier and the amount of the desorbed antigen depends on its initial dose and the dilution of the assayed sera. The irregular desorption of the antigen leads to misinterpretation of the results. Comparison of the polystyrene plates has shown that each plate is characterized by individual adsorption capacity, which impedes at present the standardization of EIA-based test systems. 相似文献
3.
E.A. Ponomareva V.E. Kartuzova E.G. Vlakh T.B. Tennikova 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(5-6):567-574
The effect of different modes of α-chymotrypsin attachment to the surface of methacrylate-based ultrashort monolithic minicolumns on enzyme activity has been studied. The immobilization of protease was carried out via direct covalent binding of chymotrypsin, as well as via its attachment through small and polymer spacers. It was established that the lowest enzyme activity against N-benzoyl-l-tyrosine ethyl ester was found for bioreactor obtained via direct attachment of chymotrypsin to the surface of GMA–EDMA minidisks, whereas the highest parameter close to that determined for dissolved enzyme was found in the case of bioreactor prepared by the introduction of copolymer of 2-deoxy-N-methacryloylamido-d-glucose with N-vinylpyrrolidone and acrolein as a long and flexible polymer spacer. Additionally, the effect of flow rate of substrate recirculation on bioconversion efficiency was examined. Independently on immobilization method, the increase of flow rate led to the raise of biocatalytic efficiency. 相似文献
4.
L N Iashina T A Ponomareva N I Rechkunova V V Zinov'ev E G Malygin 《Bioorganicheskaia khimiia》1986,12(6):764-770
The specificity of DNA X dye binding was studied. Antibiotic distamycin A was bound most strongly to the DNA sequences composed of three or more neighboring A X T pairs. Acrichin and 7-aminoacrichin proved to be weak specific inhibitors binding predominantly within the A X T regions. 相似文献
5.
Nielsen J; Peixoto AA; Piccin A; Costa R; Kyriacou CP; Chalmers D 《Molecular biology and evolution》1994,11(6):839-853
The region of the clock gene period (per) that encodes a repetitive tract
of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran
species both within and outside the Drosophilidae. All the non-
Drosophilidae sequences in this region are short and present a remarkably
stable picture compared to the Drosophilidae, in which the region is much
larger and extremely variable, both in size and composition. The
accelerated evolution in the repetitive region of the Drosophilidae appears
to be mainly due to an expansion of two ancestral repeats, one encoding a
Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and
asparagine or threonine. In some drosophilids the expansion involves a
duplication of the pentapeptide sequence, but in Drosophila pseudoobscura
both the dipeptide and the pentapeptide repeats are present in larger
numbers. In the nondrosophilids, however, the pentapeptide sequence is
represented by one copy and the dipeptide by two copies. These observations
fulfill some of the predictions of recent theoretical models that have
simulated the evolution of repetitive sequences.
相似文献
6.
R S Dreizin V Strizová T I Ponomareva L Syr?cek E M Vikhnovich N M Borovkova G V Geine E V Klimanskaya M Br?cková L Kuncová V Berkovicová 《Journal of hygiene, epidemiology, microbiology, and immunology》1979,23(2):174-185
Virological, serological and immunofluorescence studies revealed circulation of rhinoviruses of the strains 1A, 1B, 2, 3, 7, 9, 10, 12, 13, 14, 16-23, 27, 29-33, 42, 48, 53, 56, 60 and 69 on the territory of Czechoslovakia and the Soviet Union. According to virological results, type 48 predominated and was followed in frequency of occurrence by types 27, 14 and 16 in the USSR and 30, 1A and 31 in the CSSR. RV infection in adults with ARD diseases was the aetiology in 28.5% of cases. Among the causative agents of acute rhinitis, rhinosinusitis and otitis, rhinovirus infection makes up a large proportion. Interrelation has been found between rhinovirus infection and chronic inflammation of the mucosa of the nose, the accessory sinuses and the ears. Prolonged course of rhinovirus infection and isolation of the virus in the late stages of disease (1-4 months after its onset) support the presumption that rhinoviruses promote chronicity of inflammation. RV was isolated from patients with chronic pneumonia from the lower respiratory passages (bronchial secretion). Rhinoviraemia was found in a child who died of ARD. 相似文献
7.
T I Tikchonenko N M Chaplygina T I Kalinina A L Gartel T I Ponomareva B S Naroditsky R S Dreizin 《Gene》1981,15(4):349-359
The integration of DNA of highly oncogenic simian adenovirus type 7 (SA7) and non-oncogenic human adenovirus type 6 (Ad6) into the genome of newborn rat kidney cells transformed by fragmented DNA preparations was studied using reassociation kinetics and spot hybridization. Transforming DNA was fragmented with the specific endonuclease SalI (SA7) and BglII (Ad6). In contrast to the cell transformation by intact viral DNA, transformation by fragmented DNA resulted in integration into the cellular genome of not only the lefthand fragment with the oncogene but also of other regions of the viral genome. Additionally integrated fragments were stable and preserved during numerous passages of cells lines, although they were no expressed, at least in the case of the Ad6-transformed cell line. The integration of the fragments of SA7 DNA was accompanied by loss of 25-50% of the mass of each fragment. Adding the linear form of the pBR322 plasmid to the preparation of transforming Ad6 DNA also contributed to its cointegration into the genome of the transformed cell. This technique of cell cotransformation with any foreign DNAs together with the viral oncogens may be used as an equivalent of an integration vector for eukaryotic cells. 相似文献
8.
Vorobjeva L Leverrier P Zinchenko A Boyaval P Khodjaev E Varioukhina S Ponomareva G Gordeeva E Jan G 《Antonie van Leeuwenhoek》2004,85(1):53-62
Propionibacterium freudenreichii subsp. shermanii is known to prevent mutations caused by various agents such as N-methyl-N'-nitro-N-nitrosoguanidine, 9-aminoacridine, 4-nitro-quinoline-1-oxide and by UV radiation in both prokaryotic and eukaryotic cells. It was also shown to prevent or repair damage caused by H(2)O(2) or UV radiation in Salmonella typhimurium and Escherichia coli, a characteristic previously designated as reactivative effect. In order to characterise this effect at the molecular level, we have purified the active component from a P. freudenreichii cell-free extract using a combination of ammonium sulfate precipitation, anion-exchange and size-exclusion chromatography. The isolated 35 kDa protein was then identified using both N-terminal and internal peptide sequencing as a cysteine synthase. The latter was localised in the P. freudenreichii proteomic map. It is constitutively expressed but also clearly induced during adaptation to detergent and heat, but not acid, stresses. The biological meaning of cysteine synthase in the context of adaptation to oxidative and non-oxidative stresses is discussed. 相似文献
9.
L. P. Rapoport L. P. Kondratenko L. M. Orlova Kh. Kh. Nuriev V. N. Burtseva V. A. Ponomareva 《Entomological Review》2007,87(1):82-88
The species composition of fleas in the Moiynkum Desert (Chu-Talas interfluve) and indices of their domination on different hosts was established on the basis of long-term observations (1973–2000). The most significant and prolonged changes in the population density of mass flea species (Xenopsylla gerbilli minax and Coptopsylla lamellifer, parasites of the great gerbil) occur in association with changes of the population density of rodents. Changes in the population density of rodents are usually observed year after similar changes in the population density of hosts. The leading role in the transmission of the plague vector belongs to the flea X. gerbilli minax. 相似文献
10.
Vedyaykin A. D. Ponomareva E. V. Khodorkovskii M. A. Borchsenius S. N. Vishnyakov I. E. 《Microbiology》2019,88(3):245-260
Microbiology - Despite numerous studies, gaps still remain in our understanding of bacterial cell division. This review describes the basic mechanisms responsible for division of the bacterial cell... 相似文献