158 research outputs found

    The 3d-to-4s-by-2p highway to superconductivity in cuprates

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    High-temperature superconductors are nowadays found in great variety and hold technological promise. It is still an unsolved mystery that the critical temperature T_c of the basic cuprates is so high. The answer might well be hidden in a conventional corner of theoretical physics, overlooked in the recent hunt for exotic explanations of new effects in these materials. A forgotten intra-atomic s-d two-electron exchange in the Cu atom is found to provide a strong (~eV) electron pairing interaction. A Bardeen-Cooper-Schrieffer approach can explain the main experimental observations and predict the correct d_{x^2-y^2} symmetry of the gap.Comment: 4 pages, 3 figures, LaTeX2

    Study of the microcirculation level in bone with osteoporosis and osteoporotic fractures during therapy with recombinant erythropoietin, rosuvastatin and their combinations

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    The experiment was carried out in female white Wistar rats. The effects of recombinant erythropoietin, rosuvastatin and their combination were investigated based on the blood supply to the bone after a modelled experimental osteoporosis. It was found that the studied drugs prevent decrease of bone microcirculation in cases of osteoporosis and in callus tissue in experimental osteoporotic fractures, positively influencing the course of reparative regeneration of bone tissu

    Study of dose-dependent effect of 2-ethyl-6-methyl-3 hydroxypyridine succinate on the contractile function of isolated rat heat

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    In experiments on the isolated rat heart there were studied the effects of different doses (21.43 mg/kg/day and 85 . 72 mg/kg/day) 2-ethyl-6-methyl-3 hydroxypy ridine succinate ("EkoPharmInvest", Russia), on the contractile function of isolated hearts subjected to prior doxorubicin model (20 mg/kg, intraperitoneal) of pathology. The dynamic of the power mechanisms of ion transport was evaluated by imposing high h eart rate (480 BPM) and increase concentration of Са2+ to 5 mmol in perfusat

    Pharmacological correction of retinal ischemia/reperfusion by minoxidil

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    The objective of this paper was to increase the effectiveness of pharmacological correction of retinal ischemia-reperfusion by using minoxidil. Minoxidil at a dose of 0.5 mg/kg of rat mass protects the retina from ischemic-reperfusion injury. Protective effects of minoxidil are carried out by a preconditioning action, as evidenced by the lack of positive effects with the administration of glibenclamid

    Influence mechanisms of mineralocorticoid receptor antagonist (spironolactone) among elderly patients with chronic heartfailure against ischemic disease

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    It was determined that a significant positive dynamics of TNF-synthesis suppression by 67.0% (p 0.0001) was established in the 4th group of patients taking combined therapy with the blocker of mineralocorticoid receptors with spironolacton

    Development and validation of methods of quantitative determination of the new antidiabetic drug in the blood plasma of rats by high performance liquid chromatography with mass spectrometric detection

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    We developed a method of quantification of the new antidiabetic drug 3-(1h-benzimidazole-2-yl)-1,2,2-trimethyl-cyclopentane-carbonic acid (c7070) in the blood plasma of rats by high-performance liquid chromatography with mass-spectrometric detectio

    Centipede ladder at quarter filling

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    We study the ground state and excitation spectrum of a quasi one-dimensional nanostructure consisting of a pole and rungs oriented in the opposite directions ("centipede ladder", CL) at quarter filling. The spin and charge excitation spectra are found in the limits of small and large longitudinal hopping tt_\| compared to the on-rung hopping rate tt_\perp and exchange coupling II_\perp. At small tt_\| the system with ferromagnetic on-rung exchange demonstrates instability against dimerization. Coherent propagation of charge transfer excitons is possible in this limit. At large tt_\| CL behaves like two-orbital Hubbard chain, but the gap opens in the charge excitation spectrum thus reducing the symmetry from SU(4) to SU(2). The spin excitations are always gapless and their dispersion changes from quadratic magnon-like for ferromagnetic on-rung exchange to linear spinon-like for antiferromagnetic on-rung exchange in weak longitudinal hopping limit.Comment: 10 pages, 7 eps figure

    Cerebroprotective effects of 2-ethyl-6-methyl-3-hydroxypyridine-2,6-dichlorophenyl(amino)phenylethanoic acid in the treatment of purulent meningitis

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    The aim of the study was to evaluate the cerebroprotective effects of a new pharmacological compound 2-ethyl-6-methyl-3-hydroxypyridine-2,6-dichlorophenyl(amino)phenylethanoic acid (EMHDPA) on the bacterial purulent meningitis in a model of experimental pneumococcal meningiti

    Integrated evaluation of the endothelioprotective activity of an innovative peptide simulating the alpha-helix of B-erythropoethin in L-name-induced nitrogen oxide deficiency at the late gestation period

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    To study the efficiency of using carbamylated darbepoetin, asialized erythropoietin and an 11-amino acid peptide that simulating the spatial structure of the B-erythropoietin alpha-helix in the correction of L-NAME-induced nitric oxide deficiency in the late gestation perio
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