1,283 research outputs found

    Test system for evaluation of the influence of the biological activity of substances on the signal system of NF-κB: focus on the derivatives of 3- hydroxypyridine

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    At the first stage of our study, 11 pharmacological agents-inhibitors of NF-κB in vitro were screened with an estimate of the activity of the p65 subunit in mononuclear cells stimulated by bacterial lipopolysaccharide. The most active substances were: mexidol, ethoxidol and the agent under the code XS-9. Further inhibitory activity against NF-κB pharmacological agents was studied on 4 models: L-NAME-induced endothelial dysfunction, staphylococcal sepsis, acute toxic liver damage and acute pancreatiti

    Pleiotropic effects of erythropoietin. Influence of erythropoietin on processes of mesenchymal stem cells differentiation

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    The article notes that рuman recombinant erythropoietin is characterised as a factor which stimulates differentiation and proliferation of erythroid precursor cells, and as a tissue protective factor. Erythropoietin is one of the most perspective humoral agents which are involved in the preconditioning phenomeno

    Nuclear factor kappa B as a potential target for pharmacological correction endothelium-associated pathology

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    The nuclear factor kappa B (NF-κB) is one of transcription factors. A high interest in studying the biological role of the signal system and its contribution to the development of cardiovascular, oncological and autoimmune diseases is obvious. A number of stimuli (proinflammatory cytokines: tumor necrosis factor α, interleukin 1β, ligand CD40 and others) trigger the canonical and non-canonical pathways of NF-κB signaling, which increase the expression of genes regulating synthesis of cytokines and chemokines, cell proliferation and differentiation, angiogenesis, immune reactions and apoptosis. However, pathological activation of NF-κB violates the balance of substances participating in the normal activity of the cardiovascular system. This leads to the development and progression of endothelium-associated pathology and comorbidit

    Test-system for estimation of activity of GSK-3 inhibitors as antihypoxants and differentiation of endothelial progenitors in vitro

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    A model test-system was developed for validation in vitro of antihypoxic and endothelio-differentiating activity of newly created glycogen synthase kinase-3 inhibitors in comparison with the reference drug β4-thymosi

    Pharmacological modulation of cell functional activity with valproic acid and erythropoietin

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    Valproic acid (VA) is carboxylic acid with a branched chain, which is used as an antiepileptic drug. VA, which is an antiepileptic drug, is also a teratogen, which causes defects of a neural tube and an axial skeleton, although the mechanisms are not yet fully clear. It is shown that valproic acid reduces the intracellular level of oxygen active form

    Effect of the secretome of multipotent mesenchymal stromal cells induced by dexamethasone in vitro on the expression of phospho-NF-κB p65 and Ki-67 in mononuclear cells

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    To investigate the influence of secretomes from native and dexamethasone-treated adipose-derived multipotent mesenchymal stromal cells (MMSC) on the proliferation of mononuclear cells (MNCs) and on their expression of phospho-NF-κB p65 in vitr

    Creation and luminescence of size-selected gold nanorods

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    Fluorescent metal nanoparticles have attracted great interest in recent years for their unique properties and potential applications. Their optical behaviour depends not only on size but also on shape, and will only be useful if the morphology is stable. In this work, we produce stable size-selected gold nanorods (aspect ratio 1-2) using a size-selected cluster source and correlate their luminescence behaviour with the particle shape. Thermodynamic modelling is used to predict the preferred aspect ratio of 1.5, in agreement with the observations, and confirms that the double-icosahedron observed in experiments is significantly lower in energy than the alternatives. Using these samples a fluorescence lifetime imaging microscopy study observed two photon luminescence from nanoparticle arrays and a fast decay process (<100 ps luminescence lifetime), which are similar to those found from ligand stabilized gold nanorods under the same measurement conditions, indicating that a surface plasmon enhanced two-photon excitation process is still active at these small sizes. By further reducing the nanoparticle size, this approach has the potential to investigate size-dependent luminescence behaviour at smaller sizes than has been possible before

    Comments on QED with background electric fields

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    It is well known that there is a total cancellation of the \emph{factorizable} IR divergences in unitary interacting field theories, such as QED and quantum gravity. In this note we show that such a cancellation does not happen in QED with background electric fields which can produce pairs. There is no factorization of the IR divergences.Comment: 14 pages, 1 figur

    Large Deviations of the Maximum Eigenvalue in Wishart Random Matrices

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    We compute analytically the probability of large fluctuations to the left of the mean of the largest eigenvalue in the Wishart (Laguerre) ensemble of positive definite random matrices. We show that the probability that all the eigenvalues of a (N x N) Wishart matrix W=X^T X (where X is a rectangular M x N matrix with independent Gaussian entries) are smaller than the mean value =N/c decreases for large N as exp[β2N2Φ(2c+1;c)]\sim \exp[-\frac{\beta}{2}N^2 \Phi_{-}(\frac{2}{\sqrt{c}}+1;c)], where \beta=1,2 correspond respectively to real and complex Wishart matrices, c=N/M < 1 and \Phi_{-}(x;c) is a large deviation function that we compute explicitly. The result for the Anti-Wishart case (M < N) simply follows by exchanging M and N. We also analytically determine the average spectral density of an ensemble of constrained Wishart matrices whose eigenvalues are forced to be smaller than a fixed barrier. The numerical simulations are in excellent agreement with the analytical predictions.Comment: Published version. References and appendix adde

    Zero-range process with open boundaries

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    We calculate the exact stationary distribution of the one-dimensional zero-range process with open boundaries for arbitrary bulk and boundary hopping rates. When such a distribution exists, the steady state has no correlations between sites and is uniquely characterized by a space-dependent fugacity which is a function of the boundary rates and the hopping asymmetry. For strong boundary drive the system has no stationary distribution. In systems which on a ring geometry allow for a condensation transition, a condensate develops at one or both boundary sites. On all other sites the particle distribution approaches a product measure with the finite critical density \rho_c. In systems which do not support condensation on a ring, strong boundary drive leads to a condensate at the boundary. However, in this case the local particle density in the interior exhibits a complex algebraic growth in time. We calculate the bulk and boundary growth exponents as a function of the system parameters
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