546 research outputs found

    IMMUNOMODULATORY EFFECT OF SOTALOL HYDROHLORIDE UNDER ACUTE STRESS

    Get PDF
    It was established that acute stress in period induction of the local and systemic immune response to thymus-dependent antigen caused an inhibition of expression of delayed-type hypersensitivity reactions, did not effect on antibody production in the regional lymph node under the local response and suppressed of antibody production in the spleen under the systemic immune response. Administration of sotalol hydrochloride (antagonist of beta-adrenoceptors with peripheral action) canceled these changes, that points to participate in their implementation of immunosuppressive signals from the peripheral beta-adrenergic receptors

    Mutual Fund Theorem for continuous time markets with random coefficients

    Get PDF
    We study the optimal investment problem for a continuous time incomplete market model such that the risk-free rate, the appreciation rates and the volatility of the stocks are all random; they are assumed to be independent from the driving Brownian motion, and they are supposed to be currently observable. It is shown that some weakened version of Mutual Fund Theorem holds for this market for general class of utilities; more precisely, it is shown that the supremum of expected utilities can be achieved on a sequence of strategies with a certain distribution of risky assets that does not depend on risk preferences described by different utilities.Comment: 17 page

    Clinical Experience of Luminescent Diagnostics of Precancerous Diseases and Cervical Cancer

    Get PDF
    The article summarizes the experience of using luminescent diagnostics with the use of ytterbium porphyrin complexes in gynecology and oncology. A pharmaceutical composition based on the Yb complex of 2,4-dimethoxyhematoporphyrin IX was used as the luminescent markers within the infrared range. The determination of luminescence characteristics (luminescence intensity) was carried out using a laserfiber fluorimeter in the range of 900-1100 nm. A new method for diagnosis of cervical disease has been proposed. The method of luminescent diagnostics allows to conduct a survey of a large number of patients in a short time. The method of luminescent diagnostics using the ytterbium complexes of porphyrins is not invasive. The method can be used as a screening. Differences between normal and pathologically altered cervical tissue have been identified and differences between pathological changes in the cervix HSIL (CIN II, CIN III) and cervical cancer are reliable. Keywords: Cervical cancer, squamous cell carcinoma, diagnosis of cervical cancer, squamous intraepithelial lesions of high grade – HSIL, luminescent diagnostics, luminescing in the near infrared (NIR) spectral region, porphyrins, ytterbium complexes of porphyrins

    Therapeutic complement targeting in ANCA-associated vasculitides and thrombotic microangiopathy

    Get PDF
    Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are a group of systemic autoimmune disorders characterized by necrotizing inflammation of medium-to-small vessels, a relative paucity of immune deposits, and an association with detectable circulating ANCAs. AAVs include granulomatosis with polyangiitis (renamed from Wegener's granulomatosis), microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome). Until recently, AAVs have not been viewed as complement-mediated disorders. However, recent findings predominantly from animal studies demonstrated a crucial role of the complement system in the pathogenesis of AAVs. Complement activation or defects in its regulation have been described in an increasing number of acquired or genetically driven forms of thrombotic microangiopathy. Coinciding with this expanding spectrum of complement-mediated diseases, the question arises as to which AAV patients might benefit from a complement-targeted therapy. Therapies directed against the complement system point to the necessity of a genetic workup of genes of complement components and regulators in patients with AAV. Genetic testing together with pluripotent stem cells and bioinformatics tools may broaden our approach to the treatment of patients with aggressive forms of AAV

    Differential Form Valued Forms and Distributional Electromagnetic Sources

    Full text link
    Properties of a fundamental double-form of bi-degree (p,p)(p,p) for p0p\ge 0 are reviewed in order to establish a distributional framework for analysing equations of the form ΔΦ+λ2Φ=S\Delta \Phi + \lambda^2 \Phi = {\cal S} where Δ\Delta is the Hodge-de Rham operator on pp-forms Φ \Phi on R3{\bf R}^3. Particular attention is devoted to singular distributional solutions that arise when the source S {\cal S} is a singular pp-form distribution. A constructive approach to Dirac distributions on (moving) submanifolds embedded in R3{\bf R}^3 is developed in terms of (Leray) forms generated by the geometry of the embedding. This framework offers a useful tool in electromagnetic modeling where the possibly time dependent sources of certain physical attributes, such as electric charge, electric current and polarization or magnetization, are concentrated on localized regions in space.Comment: 40 page

    High frequency magnetic oscillations of the organic metal θ\theta-(ET)4_4ZnBr4_4(C6_6H4_4Cl2_2) in pulsed magnetic field of up to 81 T

    Full text link
    De Haas-van Alphen oscillations of the organic metal θ\theta-(ET)4_4ZnBr4_4(C6_6H4_4Cl2_2) are studied in pulsed magnetic fields up to 81 T. The long decay time of the pulse allows determining reliable field-dependent amplitudes of Fourier components with frequencies up to several kiloteslas. The Fourier spectrum is in agreement with the model of a linear chain of coupled orbits. In this model, all the observed frequencies are linear combinations of the frequency linked to the basic orbit α\alpha and to the magnetic-breakdown orbit β\beta.Comment: 6 pages, 4 figure

    Luminescence in anion-deficient hafnia nanotubes

    Full text link
    Hafnia-based nanostructures and other high-k dielectrics are promising wide-gap materials for developing new opto- and nanoelectronics devices. They possess a unique combination of physical and chemical properties such as insensitivity to electrical and optical degradation, radiation damage stability, a high specific surface area, and an increased concentration of the appropriate active electron-hole centers. The present paper aims to investigate the structural, optical, and luminescent properties of anodized non-stoichiometric HfO2HfO_2 nanotubes. As-grown amorphous hafnia nanotubes and nanotubes annealed at 700{\deg}C with a monoclinic crystal lattice served as samples. It has been shown that the bandgap EgE_g for direct allowed transitions amounts to 5.65±0.055.65\pm0.05 eV for amorphous and 5.51±0.055.51\pm0.05 eV for monoclinic nanotubes. For the first time, we have studied the features of the intrinsic cathodoluminescence and photoluminescence of the obtained nanotubular HfO2HfO_2 structures with an atomic deficiency in the anion sublattice at temperatures of 10 and 300 K. A broad emission band with a maximum of 2.3-2.4 eV has been revealed. We have also conducted an analysis of the kinetic dependencies of the observed photoluminescence for synthesized HfO2HfO_2 samples in the millisecond range at room temperature. It showed that there are several types of optically active capture and emission centers based on vacancy states in the O3fO_{3f} and O4fO_{4f} positions with different coordination numbers and a varied number of localized charge carriers (V0V^0, VV^-, and V2V^{2-}). The uncovered regularities can be used to optimize the functional characteristics of developed-surface luminescent media based on nanotubular and nanoporous modifications of hafnia.Comment: 15 pages, 6 figures, 3 tables, 50 reference

    Quantum oscillations in the linear chain of coupled orbits: the organic metal with two cation layers theta-(ET)(4)CoBr(4)(C(6)H(4)Cl(2))

    Full text link
    Analytical formulae for de Haas-van Alphen (dHvA) oscillations in linear chain of coupled two-dimensional (2D) orbits (Pippard's model) are derived systematically taking into account the chemical potential oscillations in magnetic field. Although corrective terms are observed, basic (alpha) and magnetic breakdown-induced (beta and 2beta - alpha) orbits can be accounted for by the Lifshits-Kosevich (LK) and Falicov-Stachowiak semiclassical models in the explored field and temperature ranges. In contrast, the 'forbidden orbit' beta - alpha amplitude is described by a non-LK equation involving a product of two classical orbit amplitudes. Furthermore, strongly non-monotonic field and temperature dependence may be observed for the second harmonics of basic frequencies such as 2alpha and the magnetic breakdown orbit beta + alpha, depending on the value of the spin damping factors. These features are in agreement with the dHvA oscillation spectra of the strongly 2D organic metal theta- theta-(ET)(4)CoBr(4)(C(6)H(4)Cl(2)).Comment: to be published in Europhysics Letters (2012

    Diffuse-Charge Dynamics in Electrochemical Systems

    Full text link
    The response of a model micro-electrochemical system to a time-dependent applied voltage is analyzed. The article begins with a fresh historical review including electrochemistry, colloidal science, and microfluidics. The model problem consists of a symmetric binary electrolyte between parallel-plate, blocking electrodes which suddenly apply a voltage. Compact Stern layers on the electrodes are also taken into account. The Nernst-Planck-Poisson equations are first linearized and solved by Laplace transforms for small voltages, and numerical solutions are obtained for large voltages. The ``weakly nonlinear'' limit of thin double layers is then analyzed by matched asymptotic expansions in the small parameter ϵ=λD/L\epsilon = \lambda_D/L, where λD\lambda_D is the screening length and LL the electrode separation. At leading order, the system initially behaves like an RC circuit with a response time of λDL/D\lambda_D L / D (not λD2/D\lambda_D^2/D), where DD is the ionic diffusivity, but nonlinearity violates this common picture and introduce multiple time scales. The charging process slows down, and neutral-salt adsorption by the diffuse part of the double layer couples to bulk diffusion at the time scale, L2/DL^2/D. In the ``strongly nonlinear'' regime (controlled by a dimensionless parameter resembling the Dukhin number), this effect produces bulk concentration gradients, and, at very large voltages, transient space charge. The article concludes with an overview of more general situations involving surface conduction, multi-component electrolytes, and Faradaic processes.Comment: 10 figs, 26 pages (double-column), 141 reference

    Anomalous terahertz photoconductivity caused by the superballistic flow of hydrodynamic electrons in graphene

    Full text link
    Light incident upon materials can induce changes in their electrical conductivity, a phenomenon referred to as photoresistance. In semiconductors, the photoresistance is negative, as light-induced promotion of electrons across the band gap enhances the number of charge carriers participating in transport. In superconductors, the photoresistance is positive because of the destruction of the superconducting state, whereas in normal metals it is vanishing. Here we report a qualitative deviation from the standard behavior in metallic graphene. We show that Dirac electrons exposed to continuous wave (CW) terahertz (THz) radiation can be thermally decoupled from the lattice by 50~K which activates hydrodynamic electron transport. In this regime, the resistance of graphene constrictions experiences a decrease caused by the THz-driven superballistic flow of correlated electrons. We analyze the dependencies of the negative photoresistance on the carrier density, and the radiation power and show that our superballistic devices operate as sensitive phonon-cooled bolometers and can thus offer a picosecond-scale response time. Beyond their fundamental implications, our findings underscore the practicality of electron hydrodynamics in designing ultra-fast THz sensors and electron thermometers.Comment: 7 pages, 3 figure
    corecore