Competitive reactions in solutions of DNA-containing polyelecrtolyte complexes

The reaction of competitive binding of two polyanions - DNA and synthetic fluorescence-tagged poly(methacrylate) (PMA^*) - with the quencher polycation poly(N-ethyl-4-vinylpyridinium) (PEVP) was studied by fluorescence quenching technique. It is found that ability of DNA to displace PMA^* from water-soluble nonstoichiometric interpolyelectrolyte complex (NPEC) formed by PMA^* and PEVP - NPEC(PMA^*-PEVP) - and to form water-soluble NPEC(DNA-PEVP) can be determined by both a parameter Ψ = P_PMA+/P_pevp, where P_pma+ and P_pevp are the degrees of polymerization of PMA^* and PEVP, respectively, and by the nature and concentration of alkali and alkali earth metal cations. According to their ability to shift the equilibrium to the right the cations can be arranged in the series Ca²⁺ > Mg²⁺ >> Na⁺ > K⁺ > Li⁺. The data obtained are in accordance with the differences in the selectivity of alkali and alkali earth cations binding with competitive polyanions.     

Synthesis of phosphorylated 1,3,5‐oxadiazines via N‐acyltrifluoroacetimidoylphosphonates

N‐Benzoyl‐ and N‐methoxycarbonyltrifluoroacetimidoylphosphonates react with dimethylcyanamide in a [4+2]‐cycloaddition to give 4‐phosphorylated 1,3,5‐oxadiazines. The structures of the products were confirmed by NMR (¹H, ¹³C, ¹⁹F, ³¹P) and IR spectra and by XRD analysis. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:22–26, 2002; DOI 10.1002/hc.1102     

Formation of bacteriochlorophyll a coordination states under external high-pressure

The pressure-dependencies up to 1100 MPa of the Q_y, Q_x, and Soret absorption bands for five- and six-coordinate monomeric complexes of bacteriochlorophyll a (Bchl a) in the solutions have been measured and quantitatively analysed. Here we show that the dependencies of the six-coordinate complexes can be accounted for within semiclassical theories, and the additional pressure-shifts in the dependencies of the five-coordinate complexes are caused by the Mg–O sixth axial ligand formation. Thereby the decrease of the Q_x and Soret transitions energies, induced by the Mg–O bond, have been estimated.     

Blind dispersion compensation for optical coherence tomography

We present a numerical method for compensating dispersion effects in optical coherence tomography that does not require a priori knowledge of dispersive properties of the sample. The method yields results equivalent to recently demonstrated quantum-optical coherence tomography, but without exploiting non-classical states of optical radiation. Dispersion compensation is accomplished by processing phase information present in standard interferograms to calculate the generalized autoconvolution function. The operation of the method can be conveniently visualized using the Wigner distribution function formalism.     

Recognition of derivability for the Lambek calculus with one division

A polynomial algorithm for determination of derivability in the Lambek calculus with one division is described in the paper.     

Linear two-phase Venttsel problems

A priori estimates are established for the two-phase boundary value problems with Venttsel interface conditions for linear nondivergent parabolic and elliptic equations. By these estimates, the existence and uniqueness theorems in Sobolev and Hölder spaces are proved.     

Erratum to “A simple analytical model of the angular momentum transformation in strongly focused light beams” by Aleksandr Ya. Bekshaev

The original version of the article was published in Central European Journal of Physics 8, 94–960 (2010), DOI: 10.2478/s11534-010-0011-2. Unfortunately, due to an editorial processing error the original version of this article contains mistakes in Eqs. (23) and (25). Here we display the corrected version of these equations.