Finite Alternation Theorems and a Constructive Approach to Piecewise Polynomial Approximation in Chebyshev Norm

Set-Valued and Variational Analysis - One of the purposes in this paper is to provide a better understanding of the alternance property which occurs in Chebyshev polynomial approximation and...     

Asymmetric hydrogenation ofN-acetyldehydrodipeptide complexes with Mg(II) and Ca(II) ions

N-Ac--Phe-AA form labile complexes with Mg(II) ions. Potentiometric titration data show that the carboxyl group of the dehydrodipeptide in them scarcely participates in complexation, unlike the complexes with Ca(II) ions. The hydrogenation of these complexes over Pd/C occurs asymmetrically, the diastereomeric excess being as high as 58%.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 601–602, March, 1993.     

Interface between an optically isotropic medium and a one-dimensional magnetoelectric photonic crystal as a controlled frequency-selective surface

The effect a constant external magnetic field has on the magnitude and direction of an energy flux carried by evanescent TM or TE wave in a two-component one-dimensional magnetic photonic crystal of the centroantisymmetric antiferromagnetic type (a nonmagnetic insulator) is investigated.     

Sets of Unique Continuation for Heat Equation

We study nodal lines of solutions to the heat equations. We interested in the global geometry of nodal sets, in the whole domain of definition of the solution. The local structure of nodal sets is a well understander subject, while the global geometry of nodal lines is much less clear. We give a detailed analysis of a simple component of a nodal set of a solution of the heat equation. Our results are motivated by some applied problems. They related to classical problems of the unique continuation and the backward uniqueness for parabolic equations.     

Reversible conformational transitions of a polymer brush containing boronic acid and its interaction with mucin glycoprotein

Reversible changes of the height of a polymer brush containing phenylboronic acid were studied. The polymer brush thickness underwent reversible changes of 0.5–1 nm, in response to the changes in composition of the contacting aqueous phase from deionized water to bicarbonate buffer and vice versa, apparently due to the conformational transition of the weak polyelectrolyte to the more extended electrically charged state. Adsorption of mucin glycoprotein to the polymer brush took place due to boronate/sugar interactions between the glycoprotein and the graft copolymer and resulted in further increase of the brush height by ca. 1.5 nm, as observed by means of spectral correlation spectroscopy and ellipsometry.

     

Discrete diffraction in a cascade-induced anisotropic lattice

The features of anisotropic discrete diffraction in a cascade-induced lattice formed by two crossed pump waves in a quadratically nonlinear medium have been studied. The transition from the diffraction of a signal beam in free space to discrete diffraction with the further capture in a waveguide in a defocusing lattice by the increasing of the pump wave intensity has been traced.     

Bivariate rational approximations of the general temperature integral

Journal of Mathematical Chemistry - The non-isothermal analysis of materials with the application of the Arrhenius equation involves temperature integration. If the frequency factor in the...     

Sequence-specific predictive chromatography to assist mass spectrometric analysis of asparagine deamidation and aspartate isomerization in peptides

Deamidation of asparagine and spontaneous isomerization of aspartic acid in proteins and peptides occur frequently. These modifications result in a mixture of peptide variants containing all three residues in the sequences. Identification and isomer quantification for these systems are challenging tasks for tandem mass spectrometry commonly utilized in protein analysis. Chromatographic data provide a set of sequence-specific information complementary to mass spectrometry. In order to compare measured retention times (RTs) with those calculated from the sequences derived from protein databases, it is necessary to develop chromatographic models and tools allowing the prediction of RT and elution order for peptides with modified residues. In this work we extended recently introduced critical liquid chromatography of biomacromolecule model for prediction of RTs for peptides containing asparagines, aspartic acid, and isoaspartic acid residues.