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This paper contains a survey of some results related to the theory of strongly inhomogeneous media and also new results on the description of finite volume eigen-oscillation spectra whose dynamics is described by effective (averaged) models of such media. UDC 517.957.6, 1. Introduction This paper contains a survey of some results related to the theory of strongly inhomogeneous media and also new results concerning the description of finite volume eigen-oscillation spectra [...]

Byline: S. A. Ivanov (1,2), R. Welz (1), M. B. Gottikh (2), S. Muller (1) Keywords: primer extension; RNA synthesis; transcription; T7 RNA polymerase Abstract: Transcription of RNA molecules from synthetic DNA templates with T7 RNA polymerase is a common procedure for the preparation of long RNA molecules. However, enzymatic synthesis does not allow for site-specific incorporation of modified nucleotides. On the other hand, RNA synthesis by chemical methods can be used for this purpose, but it is limited to RNA fragments of about 80 nucleotides at maximum. We aimed at combining both chemical and enzymatic procedures to synthesise RNA molecules by RNA primed transcription with T7 RNA polymerase. To this end, we have chemically synthesized a fluorescein-labelled RNA primer and studied elongation of this primer by T7 RNA polymerase on a single-stranded DNA template. We have shown that the enzyme is capable of extending the primer to the full-length product. The 34-mer RNA that has been synthesized by RNA primed transcription served as substrate for a twin ribozyme and was successfully cleaved in the expected manner. Author Affiliation: (1) Ruhr-Universitat Bochum, Fakultat fur Chemie, 44780, Bochum, Germany (2) Department of Chemistry and Belozersky Institute of Physicochemical Biology, Moscow State University, Moscow, 119992, Russia Article History: Registration Date: 11/12/2004

Byline: S. A. Ivanov (1,2), Ya. I. Alekseev (2), M. B. Gottikh (1) Keywords: oligodeoxyxylonucleotides; triplexes Abstract: Interactions of oligonucleotides comprising (1-[beta]-D-2'-deoxy-threo-pentafuranosyl)thymine and (1-[beta]-D-2'-deoxy-threo-pentafuranosyl)cytosine residues (oligodeoxyxylonucleotides or OXNs) with complementary single-stranded DNA fragments were investigated. Using nondenaturing gel electrophoresis, footprinting, and melting assays, pyrimidine OXNs were shown to form triplexes with the purine DNA template, which are stable at neutral pH and comparable in heat stability with the corresponding natural polypurine--polypyrimidine DNA duplexes. In such triplexes, the N3 of cytosines in one of the OXNs are protonated. As revealed by CD spectroscopy in the 210--340 nm range, the form of the triple helix depends on the nucleotide composition and sequence of the DNA template, and is intermediate between A and B. Author Affiliation: (1) Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119899, Russia (2) ZAO Sintol, Moscow, 127550, Russia Article History: Registration Date: 09/10/2004

An operation principle based on the field-effect displacement phenomenon of the perpendicularly magnetized ferrite striplines constituting the Y-junction circulator is proposed. The experimental results are in agreement with the idea that the striplines of the junction act as half-wavelength transformers ensuring 5%-8% bandwidth of the investigated circulators in the S-band without external matching. Index Terms - Stripline, Y-junction.

Particular orientations of a magnetic field irreversibly transform the ferroelectric domain structure of paramagnetic rare earth molybdates. Changes in the electric polarization of molybdates correspond to changes in the domain structure. Large magnetostrictive deformations account for the alterations in molybdates. The presence of a positive longitudinal and negative transverse magnetostriction along the crystallographic and planar axes of the applied magnetic field is predicted.

Inverted core-shell nanocrystals (NCs) are studied in which a core of a wide-gap semiconductor (ZnSe) is overcoated with a shell of a narrower gap material (CdSe). It is shown that these heterostructures can be used to significantly increase the absorption cross sections and simultaneously decrease the efficiency of Auger recombination compared to CdSe NCs emitting at the same wavelength.

The magnetic characteristics of ball-milled Cr and Mn powders were investigated using x-ray and electron microscopy and flame atomic absorption spectrometry. The results showed that the main component of the Mn and Cr powder volume was occupied by alpha-Mn and bcc Cr, respectively. The size of the Cr and Mn particles over the critical milling time of 100 minutes were less than 1 mm.