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排序方式: 共有405条查询结果,搜索用时 15 毫秒
101.
Sharova NP Dimitrova DD Abramova EB Dmitrieva SB Mikhailov VS 《Biochemistry. Biokhimii?a》2001,66(2):225-231
DNA polymerase found in an extract from eggs of the teleost fish Misgurnus fossilis (loach) has been identified as an enzyme of the type. The enzyme was purified 4000- to 5000-fold from the extract by liquid chromatography. The DNA polymerase activity was sensitive to the inhibiting action of aphidicolin but resistant to N2-(p-n-butylphenyl)-2´- deoxyguanosine 5´-triphosphate (BuPdGTP). The enzyme activity correlates with the presence of a polypeptide with molecular mass of 120-130 kD that interacts specifically with polyclonal antibodies against calf thymus DNA polymerase as revealed by Western blotting and is presumably the catalytic subunit of the enzyme. The loach DNA polymerase possesses the 3´5´-exonuclease activity specific to single-stranded DNA and catalyzes distributive elongation of primers in primer–template complexes. 相似文献
102.
Sharova NP Abramova EB Dmitrieva SB Dimitrova DD Mikhailov VS 《Biochemistry. Biokhimii?a》2001,66(4):402-409
The interaction of DNA polymerase purified from eggs of the teleost fish Misgurnus fossilis (loach) with DNA duplexes with single-strand gaps of 1-13 nucleotides was studied. In the absence of template-restricting DNA, the enzyme elongated primers on single-stranded DNA templates in a distributive manner. However, in the presence of the proximal 5"-terminus restricting the template, the enzyme activity significantly increased. In this case, the enzyme was capable of processive synthesis by filling gaps of 5-9 nucleotides in DNA duplexes. These data indicate that DNA polymerase can interact with both the 3"- and 5"-termini located upstream and downstream from the gap. Analysis of the complexes formed by DNA polymerase and different DNA substrates by electrophoretic mobility shift assay confirmed the assumption that this enzyme can interact with the proximal 5"-terminus restricting the gap. DNA polymerase displayed much higher affinity in duplexes with gaps of approximately 10 nucleotides compared to the standard template–primer complexes. Maximal affinity was observed in experiments with DNA substrates containing unpaired 3"-tails in primers. The results of this study suggest that DNA polymerase exerts high activity in the cell nuclei during repair of DNA intermediates with single strand gaps and unpaired 3"-termini. 相似文献
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A G Khomenko L I Dmitrieva Kh G Khikkel' S Miuller 《Vestnik rentgenologii i radiologii》1989,(1):14-19
A correlative study of the results of x-ray investigation using routine methods and computerized tomography (CT) was conducted to specify the roentgenomorphological substrate of changes in patients with exogenous allergic alveolitis. The established complex of routine methods is informative enough to interpret the revealed changes. However, at early stages CT helps to specify semiotics and permits obtaining additional information, particularly on quantitative, i.e. densitometric changes. In diffuse and disseminated pulmonary lesions CT can be used as an additional method. 相似文献
106.
The effect on the perception of the emotional prosody of a vocal signal of the acoustic parameters of the stimulus in children of various ages (7–10, 11–13, and 14–17 years) was studied. Considerable differences in recognition of positive and negative valences of the vocal signal against the background of noise and in its absence were demonstrated. The ontogenetic specific features of the dependence of recognition of the emotional valence on the acoustic parameters of a vocal signal were determined. The most important acoustic characters (the fundamental frequency F0 and the frequency of the first formant F1) that ensure the perception of the emotional prosody of a vocal signal against the background of noise at different age stages were found. 相似文献
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109.
Li-Yang Hsu Simon R Harris Monika A Chlebowicz Jodi A Lindsay Tse-Hsien Koh Prabha Krishnan Thean-Yen Tan Pei-Yun Hon Warren B Grubb Stephen D Bentley Julian Parkhill Sharon J Peacock Matthew TG Holden 《Genome biology》2015,16(1)
BackgroundIn the past decade, several countries have seen gradual replacement of endemic multi-resistant healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) with clones that are more susceptible to antibiotic treatment. One example is Singapore, where MRSA ST239, the dominant clone since molecular profiling of MRSA began in the mid-1980s, has been replaced by ST22 isolates belonging to EMRSA-15, a recently emerged pandemic lineage originating from Europe.ResultsWe investigated the population structure of MRSA in Singaporean hospitals spanning three decades, using whole genome sequencing. Applying Bayesian phylogenetic methods we report that prior to the introduction of ST22, the ST239 MRSA population in Singapore originated from multiple introductions from the surrounding region; it was frequently transferred within the healthcare system resulting in a heterogeneous hospital population. Following the introduction of ST22 around the beginning of the millennium, this clone spread rapidly through Singaporean hospitals, supplanting the endemic ST239 population. Coalescent analysis revealed that although the genetic diversity of ST239 initially decreased as ST22 became more dominant, from 2007 onwards the genetic diversity of ST239 began to increase once more, which was not associated with the emergence of a sub-clone of ST239. Comparative genomic analysis of the accessory genome of the extant ST239 population identified that the Arginine Catabolic Mobile Element arose multiple times, thereby introducing genes associated with enhanced skin colonization into this population.ConclusionsOur results clearly demonstrate that, alongside clinical practice and antibiotic usage, competition between clones also has an important role in driving the evolution of nosocomial pathogen populations.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-015-0643-z) contains supplementary material, which is available to authorized users. 相似文献110.
Eike J Steinig Patiyan Andersson Simon R Harris Derek S Sarovich Anand Manoharan Paul Coupland Matthew TG Holden Julian Parkhill Stephen D Bentley D Ashley Robinson Steven YC Tong 《BMC genomics》2015,16(1)