Phenomenological model of the inhomogeneous state of a material under a pulse effect

A model is proposed that takes account of features of the material state under a pulse effect. The characteristic inhomogeneous states for an unstable medium are analyzed. Their correspondence with experimentally detected effects is noted.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 50–55, June, 1990.     

Interference with heme binding to histidine-rich protein-2 as an antimalarial strategy

The erythrocytic growth stage of Plasmodium falciparum involves hemoglobin proteolysis as the primary nutrient source with the concomitant release of free heme. The liberated heme is processed by the parasite into hemozoin, a polymeric porphyrin dimer. Histidine-rich protein binds heme and mediates the formation of hemozoin, which is inhibited by the antimalarial drug chloroquine. Interference with heme binding was determined using a microtiterplate assay. Combinatorial libraries were screened and tested against parasite growth, revealing a good correlation between heme binding interference and the inhibition of parasite growth. Several of these compounds retain their potency against a chloroquine-resistant strain of Plasmodium falciparum. The most potent compounds have IC(50) values less than or equal to 50 nM against chloroquine-resistant and chloroquine-sensitive parasites.     

Self-similar approximants of the permeability in heterogeneous porous media from moment equation expansions

We use a mathematical technique, the self-similar functional renormalization, to construct formulas for the average conductivity that apply for large heterogeneity, based on perturbative expansions in powers of a small parameter, usually the log-variance of the local conductivity. Using perturbation expansions up to third order and fourth order in obtained from the moment equation approach, we construct the general functional dependence of the scalar hydraulic conductivity in the regime where is of order 1 and larger than 1. Comparison with available numerical simulations show that the proposed method provides reasonable improvements over available expansions.     

Extrapolation and interpolation of asymptotic series by self-similar approximants

The problem of extrapolation and interpolation of asymptotic series is considered. Several new variants of improving the accuracy of the self-similar approximants are suggested. The methods are illustrated by examples typical of chemical physics, when one is interested in finding the equation of state for a strongly interacting system. A special attention is payed to the study of the basic properties of fluctuating fluid membranes. It is shown that these properties can be well described by means of the method of self-similar approximants. For this purpose, the method has been generalized in order to give accurate predictions at infinity for a function, whose behavior is known only at the region of its variable close to zero. The obtained results for fluctuating fluid membranes are in good agreement with the known numerical data.     

Self-similar extrapolation from weak to strong coupling

The problem is addressed of defining the values of functions, whose variables tend to infinity, from the knowledge of these functions at asymptotically small variables close to zero. For this purpose, the extrapolation by means of different types of self-similar approximants is employed. Two new variants of such an extrapolation are suggested. The methods are illustrated by several examples of systems typical of chemical physics, statistical physics, and quantum physics. The developed methods make it possible to find good approximations for the strong-coupling limits from the knowledge of the weak-coupling expansions.     

Two-dimensional quantum antiferromagnet in a strong magnetic field

The behaviour of the two-dimensional quantum antiferromagnet of arbitrary spin in a strong transversal magnetic field on a square lattice is studied in terms of the equivalent Bose gas problem. The existence of phase transition from the state characterized by “quasi-long-range” magnetic order to the disordered ferromagnetic state is demonstrated. The expressions for correlation functions, thermodynamical and magnetic characteristics are derived.     

Einige Besonderheiten der Micellenbildung oxy?thylierter aliphatischer Alkohole

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