69 research outputs found

    The methodological problems of “human-sizedness” of modern cosmological theories

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    The article is picking up new methodological approaches to the study of the Cosmos and the understanding of the place of a human being in the Universe. The article has a methodological character and is presented in the form of the analysis and synthesis of various aspects of the study of this problem. The article considers theoretical and methodological aspects of cosmology, the analysis of modern scientific theories, the scope of their applicability. The obtained outputs can be used in cosmological modeling and in the studies of anthropological and existential aspects of cosmologyyesБелгородский госуниверсите

    Realizations of the Lie superalgebra q(2) and applications

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    The Lie superalgebra q(2) and its class of irreducible representations V_p of dimension 2p (p being a positive integer) are considered. The action of the q(2) generators on a basis of V_p is given explicitly, and from here two realizations of q(2) are determined. The q(2) generators are realized as differential operators in one variable x, and the basis vectors of V_p as 2-arrays of polynomials in x. Following such realizations, it is observed that the Hamiltonian of certain physical models can be written in terms of the q(2) generators. In particular, the models given here as an example are the sphaleron model, the Moszkowski model and the Jaynes-Cummings model. For each of these, it is shown how the q(2) realization of the Hamiltonian is helpful in determining the spectrum.Comment: LaTeX file, 15 pages. (further references added, minor changes in section 5

    Highly wear-resistant and biocompatible carbon nanocomposite coatings for dental implants

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    Diamond-like carbon coatings are increasingly used as wear-protective coatings for dental implants, artificial joints, etc. Despite their advantages, they may have several weak points such as high internal stress, poor adhesive properties or high sensitivity to ambient conditions. These weak points could be overcome in the case of a new carbon nanocomposite coating (CNC) deposited by using a C60 ion beam on a Co/Cr alloy. The structure of the coatings was investigated by Raman and XPS spectroscopy. The wear resistance was assessed by using a reciprocating tribotester under the loads up to 0.4 N in both dry and wet sliding conditions. Biocompatibility of the dental implants was tested in vivo on rabbits. Biocompatibility, bioactivity and mechanical durability of the CNC deposited on a Co/Cr alloy were investigated and compared with those of bulk Co/Cr and Ti alloys. The wear resistance of the CNC was found to be 250e650 fold higher compared to the Co/Cr and Ti alloys. Also, the CNC demonstrated much better biological properties with respect to formation of new tissues and absence of negative morphological parameters such as necrosis and demineralization. Development of the CNC is expected to aid in significant improvement of lifetime and quality of implants for dental applications

    Super duality and irreducible characters of ortho-symplectic Lie superalgebras

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    We formulate and establish a super duality which connects parabolic categories OO between the ortho-symplectic Lie superalgebras and classical Lie algebras of BCDBCD types. This provides a complete and conceptual solution of the irreducible character problem for the ortho-symplectic Lie superalgebras in a parabolic category OO, which includes all finite-dimensional irreducible modules, in terms of classical Kazhdan-Lusztig polynomials.Comment: 30 pages, Section 5 rewritten and shortene

    PREP1 tumor suppressor protects the late-replicating DNA by controlling its replication timing and symmetry

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    The synthesis of middle-to-late-replicating DNA can be affected independently of the rest of the genome by down-regulating the tumor suppressor PREP1 (PKNOX1). Indeed, DNA combing shows that PREP1 down-regulation affects DNA replication rate, increases the number of simultaneously firing origins and the asymmetry of DNA replication, leading to DNA damage. Genome-wide analysis of replication timing by Repli-seq shows that, upon PREP1 down-regulation, 25% of the genome is replicated earlier in the S-phase. The targeted DNA sequences correspond to Lamin-Associated Domains (LADs), and include late-replicating (LRRs) and temporal transition regions (TTRs). Notably, the distribution of PREP1 DNA binding sites and of its target genes indicates that DNA replication defects are independent of the overall PREP1 transcriptional activity. Finally, PREP1 down-regulation causes a substantial decrease in Lamin B1 levels. This suggests that DNA is released from the nuclear lamina earlier than in the control cells and is available for replication, thus explaining timing defects and DNA damage.This is the first evidence that the replication timing of a specific fraction of the human genome is affected by PREP1 tumor suppressor. This previously unknown function might significantly contribute to the genomic instability observed in human tumors

    Characters of the Positive Energy UIRs of D=4 Conformal Supersymmetry

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    We give character formulae for the positive energy unitary irreducible representations of the N-extended D=4 conformal superalgebras su(2,2/N). Using these we also derive decompositions of long superfields as they descend to the unitarity threshold. These results are also applicable to irreps of the complex Lie superalgebras sl(4/N). Our derivations use results from the representation theory of su(2,2/N) developed already in the 80s.Comment: 81 pages, input files: harvmac, amssym.def, amssym.tex; corrected presentation on odd reflection

    New Nanostructured Carbon Coating Inhibits Bacterial Growth, but Does Not Influence on Animal Cells

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    An electrospark technology has been developed for obtaining a colloidal solution containing nanosized amorphous carbon. The advantages of the technology are its low cost and high performance. The colloidal solution of nanosized carbon is highly stable. The coatings on its basis are nanostructured. They are characterized by high adhesion and hydrophobicity. It was found that the propagation of microorganisms on nanosized carbon coatings is significantly hindered. At the same time, eukaryotic animal cells grow and develop on nanosized carbon coatings, as well as on the nitinol medical alloy. The use of a colloidal solution as available, cheap and non-toxic nanomaterial for the creation of antibacterial coatings to prevent biofilm formation seems to be very promising for modern medicine, pharmaceutical and food industries
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