Antiaggregation Activity of Chaperones and Its Quantification

The spacial structure of proteins is rather labile and depends on external conditions. Stress conditions can cause formation of unfolded protein forms that exhibit enhanced tendency to aggregation. During biosynthesis of proteins in cells, folding of the newly synthesized polypeptide chains can be accompanied by formation of non-native protein forms with a tendency to aggregate The family of small heat shock proteins (sHsp) has a special place among the heat shock proteins; the main function of sHsp is suppression of aggregation of nonnative protein forms. Representatives of this family are found in almost all living organisms. The low molecular mass of monomers (from 12 to 43 kDa) and tendency to formation of large oligomers with molecular masses up to 1000 kDa are typical of this protein family sHsp-protein substrate complexes are characterized by a high degree of polydispersity REVIEW 1554 Abbreviations: GAPDH, glycerlaldehyde-3-phosphate dehydrogenase; HP-β-CD, 2-hydroxypropyl-β-cyclodextrin; Phb, glycogen phosphorylase b; sHsp, small heat shock protein

Stochastic Galerkin method for cloud simulation. Part II: a fully random Navier-Stokes-cloud model

This paper is a continuation of the work presented in [Chertock et al., Math. Cli. Weather Forecast. 5, 1 (2019), 65--106]. We study uncertainty propagation in warm cloud dynamics of weakly compressible fluids. The mathematical model is governed by a multiscale system of PDEs in which the macroscopic fluid dynamics is described by a weakly compressible Navier-Stokes system and the microscopic cloud dynamics is modeled by a convection-diffusion-reaction system. In order to quantify uncertainties present in the system, we derive and implement a generalized polynomial chaos stochastic Galerkin method. Unlike the first part of this work, where we restricted our consideration to the partially stochastic case in which the uncertainties were only present in the cloud physics equations, we now study a fully random Navier-Stokes-cloud model in which we include randomness in the macroscopic fluid dynamics as well. We conduct a series of numerical experiments illustrating the accuracy and efficiency of the developed approach

On mechanism of antiarrhythmic action of some dimethylphenylacetamide derivatives

The study aim was to identify essential elements of the antiarrhythmic action mechanism of tertiary and quaternary derivatives of Dimethylphenylacetamide. The study was conducted in albino rats and mice of both sexes; isolated neurons of mollusc Limnea stagnalis; and strips of rats’ right ventricle myocardium. Two compounds of Dimethylphenylacetamide LKhT- 3-00 and LKhT-12-02 were studie

Phase appearance or disappearance in two-phase flows

This paper is devoted to the treatment of specific numerical problems which appear when phase appearance or disappearance occurs in models of two-phase flows. Such models have crucial importance in many industrial areas such as nuclear power plant safety studies. In this paper, two outstanding problems are identified: first, the loss of hyperbolicity of the system when a phase appears or disappears and second, the lack of positivity of standard shock capturing schemes such as the Roe scheme. After an asymptotic study of the model, this paper proposes accurate and robust numerical methods adapted to the simulation of phase appearance or disappearance. Polynomial solvers are developed to avoid the use of eigenvectors which are needed in usual shock capturing schemes, and a method based on an adaptive numerical diffusion is designed to treat the positivity problems. An alternate method, based on the use of the hyperbolic tangent function instead of a polynomial, is also considered. Numerical results are presented which demonstrate the efficiency of the proposed solutions

Two-way multi-lane traffic model for pedestrians in corridors

We extend the Aw-Rascle macroscopic model of car traffic into a two-way multi-lane model of pedestrian traffic. Within this model, we propose a technique for the handling of the congestion constraint, i.e. the fact that the pedestrian density cannot exceed a maximal density corresponding to contact between pedestrians. In a first step, we propose a singularly perturbed pressure relation which models the fact that the pedestrian velocity is considerably reduced, if not blocked, at congestion. In a second step, we carry over the singular limit into the model and show that abrupt transitions between compressible flow (in the uncongested regions) to incompressible flow (in congested regions) occur. We also investigate the hyperbolicity of the two-way models and show that they can lose their hyperbolicity in some cases. We study a diffusive correction of these models and discuss the characteristic time and length scales of the instability

Stabilization of enzymes by dormancy autoinducers as a possible mechanism of resistance of resting microbial forms

Alkyl-substituted hydroxybenzenes (AHBs), autoinducers of microbial dormancy (or d1 factors), were found to stabilize the structure of protein macromolecules, making them metabolically less active and more resistant to stresses. In vitro experiments with the Bacillus intermedius ribonuclease and chymotrypsin showed that the degree of the physical and chemical stability of these enzymes treated with AHBs depends on their concentration and incubation time. Experiments with RNase, which is capable of refolding, i.e., renaturation after heat denaturation, revealed that AHBs efficiently interact with both intact and denatured proteins. The data obtained allow the inference to be made that d1 factors may play the role of natural chemical chaperons, blocking metabolism in dormant cells through the formation of catalytically inactive thermostable complexes with enzymes. © 2000 MAIK "Nauka/Interperiodica"

The role of microbial dormancy autoinducers in metabolism blockade

Alkyl-substituted hydroxybenzenes (AHBs), which are autoinducers of microbial dormancy (d1 factors), were found to stabilize the structure of protein macromolecules and modify the catalytic activity of enzymes. In vitro experiments showed that C6-AHB at concentrations from 10-4 to 10-2 M, at which it occurs in the medium as a true solution and a micellar colioid, respectively, nonspecifically inhibited the activity of chymotrypsin, RNase, invertase, and glucose oxidase. C6-AHB-induced conformational alterations in protein macromolecules were due to the formation of complexes, as evidenced by differences in the fluorescence spectra of individual RNase and C6-AHB and their mixtures and in the surface tension isotherms of C6-AHB and trypsin solutions. Data on the involvement of dormancy autoinducers in the posttranslational modification of enzymes and their inhibition will provide further insight into the mechanisms of development and maintenance of dormant microbial forms. © 2000 MAIK "Nauka/Interperiodica"

Модель архитектуры транспортно-логистического предприятия

The article argues that the fundamental transformations of business processes, characteristic of the era of digital economy, have so far affected Russian motor transport industry to a small extent. Digital transformation assumes a cardinal revision of the role of information technologies in management of the transportation process, based on a deep and comprehensive analysis of data, a fundamental change in approaches to organization of road transport production.To this end, it is proposed to consider the concept of enterprise architecture, covering various aspects of shaping different aspects of a transport and logistics company, as well as methods for modeling system solutions. The article analyzes transportation management system solutions, compares different approaches to the architecture of an enterprise, tools of its development like ER-charts, basic notations, life cycle, business motivation model. The suggested model semantically links real objects, ITand business processes, social aspects, and structure organisation of an enterprise.Коренные преобразования бизнес-процессов, характерные для вступления в эпоху цифровой экономики, пока ещё в незначительной степени затронули автотранспортную отрасль страны. Цифровая трансформация предполагает кардинальный пересмотр роли информационных технологий, основанных на глубоком и всеобъемлющем анализе данных, принципиальное изменение подходов к организации автотранспортного производства. С этой целью рассматриваются концепция архитектуры предприятия, охватывающая различные аспекты формирования облика транспортно-логистической компании, а также методы моделирования системных решений