N-alkenylimidazole metal complex derivatives as effective agents for the hypoxic conditions

The therapy of hypoxemic conditions by the substances, which are differing because of their key role in the vital processes of metabolism and also their high pharmacological activity, and which are known to be the regulators of redox systems, can be considered as one of the priority directions of the modern clinical and experimental pharmacology. Metal complexes of essential elements, which are the natural participants of the ligand formation, can be very interesting in this sense. The research goal. Experimental validation of the pharmacological correction of the hypoxic conditions of the N-alkenyl-, Npropargylimidazoles and 3-hydroxypyridine metal complex derivative

Morphological stability diagram for slowly and rapidly solidifying binary systems

A linear morphological stability of the solid-liquid interface is analyzed for a binary alloy in the limit of low and high crystal growth velocities. Using the result of this analysis, a diagram of morphologies is derived for a whole range of solidification rates with indicating critical growth velocities for the transitions planar front ⇔ cellular/dendritic structure. It is specially noted that the speed of solute diffusion in the bulk liquid limits the absolute chemical stability velocity from the high-rate transition cells/dendrites ⇒ planar front. © 2020, The Author(s)

Dermatoprotective activity of a combination of enoxifol with rexod in a reduced form the blood circulation in the skin in diabetes mellitus and hypercholesterinemia

Experiments in rats showed that the 9-diethylaminoethyl-2-(3,4-dioxyphenyl)-imidazo- [1,2-a]-benzimidazole dihydrobromide with the provisional name of enoxifol (0.94 - 15 mg/kg), rexod (recombinant human superoxide dismutase; 0.002 mg/kg) and especially their combination in intravenous administration in a reduced blood circulation in the skin against the background of the normoglycemia and hyperglycemia induced by experimental (alloxanic) diabetes mellitus complicated by exogenous hypercholesterinemia have a pronounced dose-dependent dermatoprotective effect, which may be due to the activation of energy processes and increase the reserve capacity of the antioxidant support network and normalization of carbohydrate and lipid metabolis

Diffuse interface models of solidification with convection: The choice of a finite interface thickness

The thin interface limit aims at minimizing the effects arising from a numerical interface thickness, inherent in diffuse interface models of solidification and microstructure evolution such as the phase field model. While the original formulation of this problem is restricted to transport by diffusion, we consider here the case of melt convection. Using an analysis of the coupled phase field-fluid dynamic equations, we show here that such a thin interface limit does also exist if transport contains both diffusion and convection. This prediction is tested by comparing simulation studies, which make use of the thin-interface condition, with an analytic sharp-interface theory for dendritic tip growth under convection. © 2020, The Author(s)

The boundary integral theory for slow and rapid curved solid/liquid interfaces propagating into binary systems

The boundary integral method for propagating solid/liquid interfaces is detailed with allowance for the thermo-solutal Stefan-type models. Two types of mass transfer mechanisms corresponding to the local equilibrium (parabolic-type equation) and local non-equilibrium (hyperbolic-type equation) solidification conditions are considered. A unified integro-differential equation for the curved interface is derived. This equation contains the steady-state conditions of solidification as a special case. The boundary integral analysis demonstrates how to derive the quasi-stationary Ivantsov and Horvay–Cahn solutions that, respectively, define the paraboloidal and elliptical crystal shapes. In the limit of highest Péclet numbers, these quasi-stationary solutions describe the shape of the area around the dendritic tip in the form of a smooth sphere in the isotropic case and a deformed sphere along the directions of anisotropy strength in the anisotropic case. A thermo-solutal selection criterion of the quasi-stationary growth mode of dendrites which includes arbitrary Péclet numbers is obtained. To demonstrate the selection of patterns, computational modelling of the quasi-stationary growth of crystals in a binary mixture is carried out. © 2018 The Author(s) Published by the Royal Society. All rights reserved.Russian Science Foundation, RSF: 16-11-1009550WM1541Data accessibility. This article has no additional data. Authors’ contributions. All authors contributed equally to the present review paper. Competing interests. The authors declare that they have no competing interests. Funding. This work was supported by the Russian Science Foundation (grant no. 16-11-10095) and the German Space Center Space Management under contract no. 50WM1541

Development perspectives of new generation medications based on the redox system regulators

This survey paper describes the necessity of the development of new medications influencing the body redox-potential. It supports the most pressing branch of pharmacology, which coincides with logically relevant attempts to shift paradigm of pharmacology from molecular to electronic, quantum-wave. This article covers and logically assorts research results of recent years and opinions of wide range of scientists from various countries. The authors also give their own assessment of the possibility to influence body redox potential. It is reported that some biophysical achievements regarded undoubtedly put a new spin in pharmacology of the biophysical leve

Trajectory and smooth attractors for Cahn-Hilliard equations with inertial term

The paper is devoted to a modification of the classical Cahn-Hilliard equation proposed by some physicists. This modification is obtained by adding the second time derivative of the order parameter multiplied by an inertial coefficient which is usually small in comparison to the other physical constants. The main feature of this equation is the fact that even a globally bounded nonlinearity is "supercritical" in the case of two and three space dimensions. Thus the standard methods used for studying semilinear hyperbolic equations are not very effective in the present case. Nevertheless, we have recently proven the global existence and dissipativity of strong solutions in the 2D case (with a cubic controlled growth nonlinearity) and for the 3D case with small inertial coefficient and arbitrary growth rate of the nonlinearity. The present contribution studies the long-time behavior of rather weak (energy) solutions of that equation and it is a natural complement of the results of our previous papers. Namely, we prove here that the attractors for energy and strong solutions coincide for both the cases mentioned above. Thus, the energy solutions are asymptotically smooth. In addition, we show that the non-smooth part of any energy solution decays exponentially in time and deduce that the (smooth) exponential attractor for the strong solutions constructed previously is simultaneously the exponential attractor for the energy solutions as well

Diffuse-interface model for rapid phase transformations in nonequilibrium systems

A thermodynamic approach to rapid phase transformations within a diffuse interface in a binary system is developed. Assuming an extended set of independent thermodynamic variables formed by the union of the classic set of slow variables and the space of fast variables, we introduce finiteness of the heat and solute diffusive propagation at the finite speed of the interface advancing. To describe the transformation within the diffuse interface, we use the phase-field model which allows us to follow the steep but smooth change of phases within the width of diffuse interface. The governing equations of the phase-field model are derived for the hyperbolic model, model with memory, and for a model of nonlinear evolution of transformation within the diffuse-interface. The consistency of the model is proved by the condition of positive entropy production and by the outcomes of the fluctuation-dissipation theorem. A comparison with the existing sharp-interface and diffuse-interface versions of the model is given.Comment: 15 pages, regular article submitted to Physical Review

The Hodograph Equation for Slow and Fast Anisotropic Interface Propagation

Using the model of fast phase transitions and previously reported equation of the Gibbs-Thomson-type, we develop an equation for the anisotropic interface motion of the Herring-Gibbs-Thomson-type. The derived equation takes the form of a hodograph equation and in its particular case describes motion by mean interface curvature, the relationship 'velocity - Gibbs free energy', Klein-Gordon and Born-Infeld equations related to the anisotropic propagation of various interfaces. Comparison of the present model predictions with the molecular-dynamics simulation data on nickel crystal growth (obtained by Jeffrey J. Hoyt et al. and published in Acta Mater. 47 (1999) 3181) confirms the validity of the derived hodograph equation as applicable to the slow and fast modes of interface propagation. This article is part of the theme issue 'Transport phenomena in complex systems (part 1)'. © 2021 The Authors.Data accessibility. Electronic supplementary material on asymptotic analysis of the hyperbolic phase field model are attached to the main text of the manuscript. Authors’ contributions. Both authors contributed to the derivation, analytical treatments and analysis of results. A.S. carried out calculations for comparison of the analytical equation with data of molecular dynamics simulations. Competing interests. We declare we have no competing interests. Funding. The funding has been made for P.K.G. by German Science Foundation (DFG-Deutsche Forschungsgemeinschaft) under the Project GA 1142/11-1. Acknowledgements. Authors thank Jeffrey J. Hoyt for his valuable explanations about molecular dynamic simulation data of Ni. P.K.G. acknowledges financial support of German Science Foundation (DFG-Deutsche Forschungsgemeinschaft). A.S. thanks M. Bennai for hosting the present work in the research activities of LPMC