3,918 research outputs found

    Построение асимптотического разложения решения уравнения нейрона, описываемого дифференциальным уравнением с переменным запаздыванием

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    The difference-differential equation with variable delay which describes an impulse neuron model is analyzed. The asymptotic expansion of solution of the equation constructed in the paper has the higher order in comparison with the result of the previous research.Исследуется дифференциальное уравнение с переменным запаздыванием, описывающее динамику биологической нервной клетки. Построено асимптотическое разложение решения уравнения, имеющее более высокий порядок по сравнению с результатами предыдущих работ

    Релаксационные циклы обобщённого уравнения импульсного нейрона

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    In the paper we analyze the generalized model of the V. V. Mayorov and I. Yu. Myshkin pulsed neuron. The neuron equation contains a delay of the sodium conductance with respect to the transmembrane potential as well as the potassium one. We proved the exisence and stability of the periodic solution and obtained its asymptotic expansion.Рассмотрена обобщенная модель импульсного нейрона В. В. Майорова и И. Ю. Мышкина. В уравнение, описывающее нейрон, введено запаздывание не только калиевой, но и натриевой проводимости относительно трансмембранного потенциала. Доказаны существование и устойчивость периодического решения уравнения нейрона, построено асимптотическое разложение решения

    Construction of the Initial Part of a Ion Linear Accelerator from Similar Short Cavities

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    The construction of the initial part of a normally conducting linac for hydrogen ion beams with a pulsed current of ~20 mA up to an energy of ~70 MeV is considered. The RFQ at a frequency of ~160 MHz accelerates ions to an energy of ~4 MeV. Further acceleration is carried out at a doubled frequency by short, up to 5βλ5\beta\lambda, cavities, operating in the TM010 mode, with drift tubes. Focusing is carried out by doublets of quadrupole lenses placed between the cavities. The structure of the accelerating-focusing channel, with given beam parameters, with reserves provides both the conditions for stable longitudinal and transverse motion of particles, and reliable technical implementation. The main results of the simulations of particle dynamics and the main parameters of the elements of the channel are presented. The possibility of constructing an linac with a higher output energy is analyzed.Comment: in Russian languag

    THE USE OF NEW REAGENT KITS FOR DETECTION AND DESCRIPTION OF ADDITIONAL ALLELES

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    During the screening typing of recruited volunteers with Volga Federal District for unrelated hematopoietic stem cell registry on the loci (HLA)-A, B, DRB1, DRB345 in sample No 1758 identified a new allele at locus A. The use of basic kit AlleleSEQR HLA-A Sequencing in combination with HARP – A2F98A allowed to determine the genotype of this sample – А*30:01:01, a new allele А*25, В*13, 44, DRB1*03, 09, DRB3*02, DRB4*01

    Thz range low-noise sis receivers for space and ground-based radio astronomy

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    We report on research in the field of low-noise receiving systems in the sub-terahertz (THz) range, carried out in recent years, aimed at developing receivers with quantum sensitivity for implementation in space and ground-based radio telescopes. Superconductor-Insulator-Superconductor (SIS) mixers based on high-quality tunnel junctions are the key elements of the most sensitive sub-THz heterodyne receivers. Motivations and physical background for technology improvement and optimization, as well as fabrication details, are described. This article presents the results of the SIS receiver developments for the 211–275 GHz and 790–950 GHz frequency ranges with a noise temperature in the double sideband (DSB) mode of approximTELY 20 K and 200 K, respectively. These designs and achievements are implemented in the development of the receiving systems for the Russian Space Agency mission “Millimetron”, and for the ground-based APEX (Atacama Pathfinder EXperiment) telescope

    Reconstruction of recombination sites in genomic structures of the strains of genotype 6 of hepatitis C virus

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    The encoded portion of the complete genomes of 46 strains of the genotype 6 of hepatitis C virus through bioinformatics RDP programs complex group of 6 recombinants strains was identified, in which 7 recombination sites were fixed. Strains correspond to the three-recombinant HCV subtypes: 6a, 6b and 61. For each of the identified recombinant we defined parent strains from which they can be obtained. Three recombinants were obtained from parent strains of the same subtype (homologous inside subgenotypic recombination). For the remaining three recombinants parent strains were members of three different subtypes (between subgenotypic recombination).In one strain we identified a unique recombination site in a highly conservative NS3 gene. Most of the recombination sites occurred in the region of the structural genes C, E1 and E2, and in the area of non-structural genes NS5a and NS5b.In the recombinant strain DQ480518-6a two recombination site were identified. One site is located in the structural and nonstructural genes (E2 + NS1 + NS2), and a second one in non-structural region. Dimensions of recombination sites can vary from 86 to 1072 nucleotide bases. The study identified "hot spots" of recombination in the strains of genotype 6 of hepatitis C virus. The recombinants were found in the population of the three countries: the United States (from the serum of an immigrant), Hong Kong and China

    Immunogenetic characteristics of unrelated hematopoietic stem cell donors recruited in the Sverdlovsk, Saratov, Yaroslavl and Vladimir regions

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    Aim of the study was to investigate the distribution features of HLA alleles and multilocus haplotypes in potential donors of hematopoietic stem cells recruting in the Sverdlovsk, Saratov, Yaroslavl and Vladimir regions. Material and methods. Sequence Based Typing technology was used to identify human leukocyte antigen (HLA)-A, -B, -C, -DRB1 alleles from 2683 Russian unrelated bone marrow volunteers living in the Sverdlovsk (n = 1018), Saratov (n = 825), Yaroslavl (n = 604) and Vladimir (n = 236) regions. HLA allele and haplotype frequencies were estimated via maximum-likelihood analysis from genotypic data through an expectation-maximization (EM) algorithm for unknown gametic phase. Results and discussion. In all studied populations, 16 HLA-A, 13 HLA-C, 13 HLA-DRB1 alleles were selected. In the locus HLA-B, 28 alleles were detected in the populations of the Sverdlovsk and Yaroslavl regions, 27alleles – in the Saratov region, 25 alleles – in the Vladimir. Seventeen alleles, HLA-A*02, HLA-A*03, HLA-A*01, HLA-A*24, HLA-B*07, HLA-B*35, HLA-С*07, HLA-С*06, HLA-С*04, HLA-С*03, HLA-С*12, HLA-DRB1*15, HLA-DRB1*07, HLA-DRB1*01, HLA-DRB1*13, HLA-DRB1*04, HLA-DRB1*11 exhibit frequencies over 10 %. The highest frequency extended haplotype in the all studied populations HLA-A*01-B*08-C*07-DRB1*03, was observed frequencies of 4,4 % – in the Sverdlovsk region, 3,2 % – in the Saratov region, 4,9 % – in the Yaroslavl region and 4,2 % – in the Vladimir region. Routine HLA typing allowed us to define four new HLA alleles in the populations of the Sverdlovsk and Saratov region

    IZOENZYME STRUCTURE OF POPULATIONS OF TICKS IXODES PERSULCATUS SCHULZE (ACARI: IXODIDAE) IN RECREATION AREAS OF IRKUTSK CITY

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    Allozyme structure of the population of ticks Ixodes persulcatus in 8 enzyme systems is shown in two samples of ticks from the recreational areas in suburbs of Irkutsk. From the total of 13 loci, which encode these enzymes, eight were polymorphic. Based on allozyme analysis of populations of mites, it is found that most of them show intrapopulation heterogeneity and. the lack of difference between the two populations from different foci. A similar pattern may indicate a large rate of migration of genes between populations and. their close relatives

    Comorbid disease in children and adolescents with perinatal HIV infection: A pilot study

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    Background. With the increased use of combination antiretroviral therapy, the mortality of people living with HIV has decreased significantly, which has led to an increase of comorbidity and secondary HIV-related pathology in both adults and also in children and adolescents living with HIV infection. The incidence of children and adolescents with HIV infection and those in the general population varies significantly.The aim. To assess the frequency and range of chronic comorbidities in children and adolescents with perinatal HIV infection Methods. We carried out an observational study. Data on the incidence of 161 children with perinatal HIV infection registered in the Irkutsk Regional AIDS Center were copied.Results. Overall incidence of tuberculosis (18633.5 per 100 000 children), diseases of the digestive system (24844.7 per 100 000 children), diseases of the eye and adnexa (28571.4 per 100 000 children), diseases of the nervous system (18012.4 per 100 000 children), mental and behavioral disorders (13,664.6 per 100 000 children) in children with perinatal HIV infection is the higher than in children of comparable age. The overall incidence values of the endocrine system diseases, eating and metabolic disorders, diseases of the ear and mastoid process, diseases of the circulatory system, diseases of the genitourinary system, as well as congenital disorders and chromosomal disorders in children and adolescents with and without perinatal HIV infection are comparable.Conclusion. The prevalence of diseases of the circulatory, respiratory and genitourinary systems in children with perinatal HIV infection is comparable to that in the corresponding population. Prevalence of tuberculosis, anemia, diseases of the gastrointestinal tract, diseases of the eye and adnexa, diseases of the nervous system, mental and behavioral disorders is higher compared to children not exposed to HIV
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