Defined folding pattern of poly(rG) supports inherent ability to encode biological information.

The RNA World hypothesis posits that RNA can represent a primitive life form by reproducing itself and demonstrating catalytic activity. However, this hypothesis is incapable of addressing several major origin-of-life (OoL) questions. A recently described paradox-free alternative OoL hypothesis, the Quadruplex (G4) World, is based on the ability of poly(dG) to fold into a stable architecture with an unambiguous folding pattern using G-tetrads as building elements.

Structure of Tetrahelical DNA Homopolymers Supports Quadruplex World Hypothesis.

We previously reported a tetrahelical monomolecular architecture of DNA, tmDNA, which employs G-quartets and an all-parallel GGGTGGGTGGGTGGG (G3T) quadruplex as the repeating unit. Based on thermodynamic and kinetic studies, we proposed that covalently joined (G3T) units formed an uninterrupted programmable homopolymer; however, structural evidence for the tmDNA architecture was lacking. Here, we used NMR spectroscopy of wild-type and single-inosine-substituted constructs to characterize both monomolecular (G3T) and bimolecular quadruplex-Mg-coupled versions of tmDNA.

A Chimeric DNA/RNA Antiparallel Quadruplex with Improved Stability.

Nucleic acid quadruplexes are proposed to play a role in the regulation of gene expression, are often present in aptamers selected for specific binding functions and have potential applications in medicine and biotechnology. Therefore, understanding their structure and thermodynamic properties and designing highly stable quadruplexes is desirable for a variety of applications. Here, we evaluate DNA→RNA substitutions in the context of a monomolecular, antiparallel quadruplex, the thrombin-binding aptamer (TBA, GGTTGGTGTGGTTGG) in the presence of either K or Sr .

LASER INDUCED FLUORESCENCE OF SKIN: SUPERPOSITION OF SPECTRAL INTENSITIES.

The aim of the work was to determine the possibility of assessing the state of human health by the method of optical spectroscopy of skin and nail. To achieve this goal, Laser-Induced Fluorescence (LIF) spectroscopy was used. A special probe was designed, which makes it possible to record differential spectra and, as a result, to compare the shapes of spectral fluorescence lines.

APPLICATION OF ANTIBIOTIC-CONTAINING EAR DROPS IN TREATMENT OF ACUTE OTITIS MEDIA.

Otitis is a serious and noteworthy disease. Only timely and adequate treatment guarantees to cure it and prevent complications. The present study involved 250 patients, raining in age from 2 to 64 years.