208 research outputs found

    Cyclic nucleotides in tissues during long-term hypokinesia

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    Male Wistar rates were kept hypokinetic by placing them in small containers for 22 days. Blood plasma cAMP content was subsequently found increased, and cGMP content decreased, in the experimental animals. Liver and thymus cAMP content was similar in the control and experimental animals. There was a 20 and 38% decrease of cAMP content in the kidneys and spleen, respectively. Hypokinesia's reduction of cyclic nucleotides seems to inhibit RNA and protein synthesis

    Changes of the body functions during long-term hypokinesia

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    Prolonged hypokinesis (100-170 days) studied in 2000 rats kept in cages limiting their mobility provoked considerable changes in the gaseous and energetic metabolism: an elevation of the total gaseous metabolism and of the rate of O2 requirement by the muscles (in the late periods of hypokinesis) and a change in the intensity of tissue respiration of the liver and myocardium. There also proved to be a reduction in the level of phosphorylation and separation of oxidative phosphorylation in the myocardium, liver, and partially in the skeletal muscle. Prolonged hypokinesia led to changes in tissue metabolism: a disturbance of development of the animals, a marked delay and an increase in the weight of the organism and the muscular system, and disturbances of the mineral and protein metabolism. Prolonged hypokinesis also lead to exhaustion of the hypothalamus-hypophysis-adrenal cortex system

    Polymeric laser-active media: The possibility of lasing and exploitable properties advance

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    Laser-spectroscopic studies of polymeric laser-active media based on Rhodamaine 6G dye incorporated into modified Methylmethacrylate with Methacrylic Acid copolymer samples had been carried out. Absorption and luminescence spectra together with luminescence quantum yield were studied. The basic parameters of the laser oscillation and their stability were obtained. The new potential photostabilizator azotes- and sulphurs-containing organic compounds - Thiourea and Thiazol aromatic derivatives was specially synthesized and their role to dye and polymeric host photochemical stability were studied. In this paper it was shown that these synthesized compounds indeed are high effective photostabilizators. Also it was demonstrated that using of these additives leads to significant increasing of laser action efficiency, from one hand and to rising the working characteristics (operational lifetime) of solid-state laser-active media based on the new synthesized polymer composition materials, from other hand

    Manipulations with early mouse embryos for generation of genetically modified animals

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    Recently, genome-editing technologies have  become more efficient and accessible. The discovery of nucleases for directional genome editing (CRISPR/Cas9, TALEN, ZFNs) significantly accelerated and simplified the production of mice with targeted gene editing in the genome. Until last time, the CRISPR/Cas9 system noticeably simplified the preparation of knockout or transgenic mice. CRISPR/Cas9 technology was successfully applied for gene knockout and knock-in, generation of large deletions or directed insertions in targeted genome regions in embryonic stem cells (ESCs).When injected into blastocysts, such  modified ESCs are able to generate chimeras producing gametes with an identical genotype with ESC. Thus, it can identify animals with modified genomes. More recently, CRISPR/Cas9 technology was successfully applied to mouse zygotes and the birth of genetic modified mice was observed, i. e., the time required for generating genome-modified animals decreased significantly. The CRISPR/Cas9 system allows making gene knockout, large deletions or directed insertions into the target region of the genome by cytoplasm or pronuclear microinjection into zygotes. In addition, this is faster and simpler than similar work with mouse ESCs. Meanwhile, methods of manipulation with early embryos and their transplantation to surrogate mothers may be somewhat tricky. Therefore, it is important to use modern technologies for directional genome editing and perfect mastery in the embryological technics. In this article, we describe the protocols of microinjection into the pronucleus or cytoplasm of zygotes and injection of embryonic stem cells into the blastocyst cavity. We also describe embryological methods, such as superovulation, preparation of early stage  embryos,  surgical operation, production of foster mice. In addition, we describe the assembly and necessary components for the isoflurane anesthetic apparatus and isoflurane anesthesia

    Features of Adaptation of Students with Disabilities at the University

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    Admission to the first year entails significant changes in the life of a freshman her adaptation of a student takes on average one year, adaptation of a student with disabilities can take up to three years. In this article we will consider the factors to which it is necessary to adapt the student in the process of studying at the University.Поступление на первый курс влечет за собой значительные изменения в жизни студента, его адаптация занимает в среднем один год, адаптация студента с ограниченными возможностями может затянуться до трех лет. В данной статье мы рассмотрим факторы, к которым необходимо адаптироваться студенту в процессе обучения в вузе

    Arctic strategies for socio-economic development of circumpolar states: national and regional aspects

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    In the presented paper, the authors have revealed some key priorities of the state Arctic policies of circumpolar countries on the base of the analysis of political and programmatic documents. The analysis of political and programmatic documents has shown that the state Arctic policies of the circumpolar countries are focused on expanding external interaction in the Arctic and maintaining the sustainable development of their own Arctic territorie

    Features of Adaptation of Students with Disabilities at the University

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    Admission to the first year entails significant changes in the life of a freshman her adaptation of a student takes on average one year, adaptation of a student with disabilities can take up to three years. In this article we will consider the factors to which it is necessary to adapt the student in the process of studying at the University.Поступление на первый курс влечет за собой значительные изменения в жизни студента, его адаптация занимает в среднем один год, адаптация студента с ограниченными возможностями может затянуться до трех лет. В данной статье мы рассмотрим факторы, к которым необходимо адаптироваться студенту в процессе обучения в вузе

    On the Issue of Improving the Legal Regulation of the Work of Teaching Staff

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    Повышение внимания общества к системе образования, к возникающим в этой системе правоотношениям, к участникам этих отношений обусловили необходимость анализа правовых норм регулирования труда педагогических работников. В статье представлен краткий анализ изученного состояния, даны предложения по изменению действующего законодательства, направленные на совершенствование правового регулирования труда педагогических работников образовательных организаций.The increased attention of society to the education system, to the legal relations arising in this system, to the participants in these relations necessitated the analysis of legal norms regulating the work of teaching staff. The article presents a brief analysis of the studied state, offers proposals for changing the current legislation aimed at improving the legal regulation of the work of teaching staff of educational organizations

    Genome editing using CRISPR/ Cas9 system: a practical guide

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    Over the past few years, the CRISPR/Cas techniques have become a revolution in genome editing. Since the original paper on CRIPSR/Cas9 genome editing, researches have proposed numerous modifications of the key components of the CRISPR/Cas9 system to make it extremely efficient. Nowadays, CRISPR/Cas systems can be used not only to modify genomes, but also to control expression levels of defined genes, visualize loci of interest in the space of living cell nuclei, change methylation status of mammalian CpG sites, and to serve many other purposes. Due to an extremely high efficacy and ease of usage, the CRISPR/ Cas system has been employed in a large number of studies in various areas of biology and biotechnology. We have recently published a review describing various CRISPR/Cas systems, mechanisms of their functioning, and applications of the techniques in details. Despite the broad range of potential applications of CRISPR/Cas systems, they are mostly used for genome editing. And, however simple the system may be, there is a number of potential pitfalls on the way towards its use in CRISPR/Cas- naïve laboratory settings. In this article, we describe protocols of CRISPR/Cas9 system generation. We start with a short description of theoretical aspects underlying Cas9-mediated genome editing. Next, we describe a step-by-step protocol of guide RNA vector design and assembly, and several ways of qualitative and quantitative evaluations of the system. Finally, we report protocols of genome editing for modification of embryonic stem cells and zygotes

    A hypomorphic mutation in the mouse Csn1s1 gene generated by CRISPR/Cas9 pronuclear microinjection

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    Caseins are major milk proteins that have an evolutionarily conserved role in nutrition. Sequence variations in the casein genes affect milk composition in livestock species. Regulatory elements of the casein genes could be used to direct the expression of desired transgenes into the milk of transgenic animals. Dozens of casein alleles have been identified for goats, cows, sheep, camels and horses, and these sequence variants are associated with altered gene expression and milk protein content. Most of the known mutations affecting casein genes’ expression are located in the promoter and 3’-untranslated regions. We performed pronuclear microinjections with Cas9 mRNA and sgRNA against the first coding exon of the mouse Csn1s1 gene to introduce random mutations in the α-casein (Csn1s1) signal peptide sequence at the beginning of the mouse gene. Sanger sequencing of the founder mice identified 40 mutations. As expected, mutations clustered around the sgRNA cut site (3 bp from PAM). Most of the mutations represented small deletions (1–10 bp), but we detected several larger deletions as well (100–300 bp). Functionally most mutations led to gene knockout due to a frameshift or a start codon loss. Some of the mutations represented in-frame indels in the first coding exon. Of these, we describe a novel hypomorphic Csn1s1 (Csn1s1c.4-5insTCC) allele. We measured Csn1s1 protein levels and confirmed that the mutation has a negative effect on milk composition, which shows a 50 % reduction in gene expression and a 40–80 % decrease in Csn1s1 protein amount, compared to the wild-type allele. We assumed that mutation affected transcript stability or splicing by an unknown mechanism. This mutation can potentially serve as a genetic marker for low Csn1s1 expression
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