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931.
N. A. Malygina A. S. Melent'ev I. V. Kostomarova I. A. Melent'ev R. T. Saigitov Yu. B. Smirnova L. D. Serova 《Molecular Biology》2001,35(5):667-670
Allele and genotype frequencies of the HindIII polymorphism of the lipoprotein lipase (LPL) gene were studied in patients with myocardial infarction (MI) and stable angina of effort (SAE), including long-lived people (over 90). The polymorphism proved to be associated with MI and with the life span, genotype H+/H+ being predisposing to MI and allele H– being protective. The allele and genotype frequencies of long-lived people differed significantly from the Hardy–Weinberg proportions and from those of SAE patients aged up to 90. An excess of heterozygotes in this group suggests a selective pressure which eliminates homozygotes. Possibly, heterozygotes H+/H– have an adaptive advantage, which provides for their longevity. 相似文献
932.
G.?I.?Tsereteli T.?V.?Belopolskaya N.?A.?GruninaEmail author O.?I.?Smirnova A.?Yu.?Romanova 《Biophysics》2017,62(1):43-52
Differential scanning calorimetry (DSC) was used to study the melting and crystallization of frozen water dispersed in humid potato starch. Melting and crystallization temperatures and heats as functions of the degree of hydration of the starch were obtained for native and amorphous starch states. Manifestations of the size effect were observed in the dependences of heat for the processes in both starch states. Crystallization and melting heats of frozen water were found to change nonlinearly with the increasing degree of hydration in all cases. In contrast, a size effect in the dependences of melting and crystallization temperatures of frozen water was detected only for native starch. Reasons responsible for the absence of a size effect in the amorphous state were considered. Hysteresis, which is characteristic of small particles, was observed upon melting and crystallization of frozen water and its manifestation strongly differed in the native and amorphous states of potato starch. 相似文献
933.
S. L. Smirnova I. M. Roshchevskaya 《Journal of Evolutionary Biochemistry and Physiology》2017,53(2):129-134
In psychrophilic and thermophilic fish, significant differences were revealed under an optimal body temperature in the heart rate, initial atrial activity duration and descending slope of the P II wave. Differences were also detected in atrial electric activity during the initial and final periods of depolarization, reflecting different localization of the initial excitation area and the movement of the depolarization front toward the atrioventricular border. 相似文献
934.
A.?Ergeshov S.?N.?AndreevskayaEmail author E.?E.?Larionova T.?G.?Smirnova L.?N.?Chernousova 《Molecular Biology》2017,51(4):526-532
To study the transmissibility of drug resistant mutant clones, M. tuberculosis samples were isolated from the patients of the clinical department and the polyclinic of the Central TB Research Institute (n = 1455) for 2011–2014. A number of clones were phenotypically resistant to rifampicin (n = 829), isoniazid (n = 968), and fluoroquinolones (n = 220). We have detected 21 resistance-associated variants in eight codons of rpoB, six variants in three codons of katG, three variants in two positions of inhA, four variants in four positions of ahpC, and nine variants in five codons of gyrA, which were represented in the analyzed samples with varied frequencies. Most common mutations were rpoB 531 Ser→Leu (77.93%), katG 315 (Ser→Thr) (94.11%), and gyrA 94 (Asp→Gly) (45.45%). We found that the mutations at position 15 of inhA (C→T) (frequency of 25.72%) are commonly associated with katG 315 (Ser→Thr). This association of two DNA variants may arise due to the double selection by coexposure of M. tuberculosis to isoniazid and ethionamide. The high transmissibility of mutated strains was observed, which may be explained by the minimal influence of the resistance determinants on strain viability. The high transmissibility of resistant variants may also explain the large populational prevalence of drug-resistant TB strains. 相似文献
935.
Formulation of organic and inorganic hydrogel matrices for immobilization of β‐glucosidase in microfluidic platform 下载免费PDF全文
Aslihan Kazan Marcel Heymuth Dilan Karabulut Seref Akay Ece Yildiz‐Ozturk Rabia Onbas Cahit Muderrisoglu Sayit Sargin Rene Heils Irina Smirnova Ozlem Yesil‐Celiktas 《Engineering in Life Science》2017,17(7):714-722
The aim of this study was to formulate silica and alginate hydrogels for immobilization of β‐glucosidase. For this purpose, enzyme kinetics in hydrogels were determined, activity of immobilized enzymes was compared with that of free enzyme, and structures of silica and alginate hydrogels were characterized in terms of surface area and pore size. The addition of polyethylene oxide improved the mechanical strength of the silica gels and 68% of the initial activity of the enzyme was preserved after immobilizing into tetraethyl orthosilicate–polyethylene oxide matrix where the relative activity in alginate beads was 87%. The immobilized β‐glucosidase was loaded into glass–silicon–glass microreactors and catalysis of 4‐nitrophenyl β‐d ‐glucopyranoside was carried out at various retention times (5, 10, and 15 min) to compare the performance of silica and alginate hydrogels as immobilization matrices. The results indicated that alginate hydrogels exhibited slightly better properties than silica, which can be utilized for biocatalysis in microfluidic platforms. 相似文献
936.
We examined the organization of microtubule system of interphase cells in roots of Medicago sativa L. during acclimation to salt and osmotic stress at different concentrations of NaCl, Na2SO4, and mannitol. We identified morphological changes of tubulin cytoskeleton in different root tissues during the acclimation to salt and osmotic stress: (1) decreased density of the cortical microtubule network, (2) random orientation of cortical microtubule bundles, (4) thickening of the bundles, (3) nonuniform density of the bundles, (4) fragmentation of the bundles, and (5) formation of microtubule converging centers. Network thinning and thickening of the bundles were observed both under osmotic and salt stress. Random orientation of cortical microtubules was visualized under osmotic stress but not during salt stress. Fragmentation of microtubule bundles took place under salt stress with a high concentration of mannitol. Formation of microtubule converging centers was common under prolonged action of sodium sulfate, less evident under sodium chloride, and not found after mannitol treatment. Our data show that, in alfalfa root cells, cortical microtubules rearrange not only in response to different ions, but also to osmotic pressure. Thus, the signaling pathways and molecular mechanisms inducing reorganization of the microtubule system may be triggered by sodium cations, as well as by sulfate and chloride anions at concentrations that do not cause irreversible cell damage. 相似文献
937.
Stabilization of P53 protein in cells isolated from patients with a grave hereditary disease ataxia-telangiectasia (AT), characterized by strongly enhanced sensitivity to ionizing radiation and impairment of cell cycle control after DNA damage, was studied. The level of expression of these reactions by patients may vary, and it tends to be linked with the severity of the disease. In all AT strains studied, both acquired by the authors and obtained from foreign colleagues, we observed the alteration of timing and character of stabilization of P53 protein, after the action of ionizing radiation in sublethal dosage, as compared to that in cells from healthy donor. 相似文献
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