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The effect structural changes in fractal-like multilayered structures with metamaterial inserts have on the stability of the shape of fractal patterns in their optical spectra is investigated. Calculations using the model of approximants allows scaling parameters to be obtained that establish the relationship between structural features and their optical spectra.

Algorithms for constructing dendrites and analyzing their fractal characteristics are considered. Multi-parameter identification that includes the determination of scaling parameters is proposed. Patterns that determine the relationship between the structure features of dendrites and their diffraction patterns are obtained.

A simple method for constructing a 2D fractal cluster of nanodendrities formed in the self-organization process of nanoparticles is presented. The relationship between the structural features of dendrite-type lattices and the fractal characteristics of both studied objects and their diffraction patterns is revealed.

Fractal pattern analysis is performed for aperiodicmultilayer systems with metamaterials. Morphological features of pattern formation in optical characteristics of structures with different geometry are revealed having regard to the manifestation of the phase-compensation effect and presence of metamaterial layers.

Current advances in the development of tools of environmental monitoring for anticholinesterase agents are considered. The aim of this analysis was to substantiate the most promising trends in the development of an up-to-date biosensor based on cholinesterase inhibition with an optimum sensitivity-analytical-signal formation time relation for the monitoring of atmospheric air for organophosphorus warfare agents and insecticides.

Sometimes it is necessary to fine determine the position of the optical axes of the convex-concave lenses, such as eyeglass lenses. If the lens has not yet been processed, and its boundary has the shape of a perfect circle — it's not hard to do. The problem occurs when the lens has already given shape to be installed in the frame. Currently, a mechanical method for determining the thickness of the lens has not a high accuracy. The proposed method for determining the position of the optical axis of the lens uses a double reflection of the laser beam. The reflected beams from the front and rear sides of the lenses create two point light source. These sources create a remote screen system of equal inclination rings. Observe the center of these rings on the screen is possible, if the laser beam falls into the thinnest position diverging lens or in the thickest collecting one. This method is applicable both for scattering as well as for collecting lenses. Lenses can be rotated to the laser beam, both convex and concave side. This method is also applicable to the adjustment lenses located on an optical bench. Since the angular dimensions of the rings are determined radii of curvature of the lens, its thickness and refractive index, the method can be used to determine the curvature of the lens surface.

On the basis of the use of fractal concepts the conditions for the stability of patterning structures in the optical spectra of approximants aperiodic structures are defined. The conditions of the optical characteristics of different types of equivalence approximants are described.

A rapid test for amanitins is proposed on the basis of their complexation with ethydium bromide leading to an intensively fluorescent adduct; the fluorescence band of the product has a shorter wavelength than that of ethydium bromide, which ensures the high specificity of the analysis. The fluorescence intensity in the system of ethydium bromide — amanitin grows linearly with the concentration of amanitin in the range 0.2–1.7 μM at the constant concentration of ethydium bromide, 0.6 μM. The detection limit is 1 μM, the time of the development of the analytical signal is up to 5 s.

A method for determining the structural features of 1D–3D aperiodic diffraction gratings with self-similarity symmetry has been proposed and substantiated. This method is based on the analysis of local patterns in scaling characteristics of diffracted waves. The stability of patterns to changes in grating illumination conditions and the presence of defects in gratings is estimated.

This work is aimed at solving one of the fundamental problems of modern fractal optics. The goal is to establish general laws that relate structural features of fractal-like systems and their associated spectral characteristics. Establishing such laws allows finding new diagnostic approaches for exploration of fractal-like systems and their formation processes. Nanocluster systems and multilayer structures, also with inclusion of metamaterial inserts, were chosen as the objects of research. A wide variety of applications of varying physical nature is enabled as fractal optics successfully penetrate into interdisciplinary technologies and theoretical concepts. In this work, particular interest is paid to scaling properties of structures of the studied systems and their optical characteristics. Based on theoretically obtained amplitude and phase distributions of light waves that diffract or interfere in the analyzed systems, the features of scaling in light fields are determined. When analyzing the obtained modeling results, a comparison is made between the structural features of the studied systems revealed by the scaling parameters in diffraction patterns and transmission spectra.

Modern views on the structure of cholinesterase active sites and the mechanism of their interaction with organophosphorus inhibitors are considered. The attention is focused on the mechanism of the effect of cholinergic receptor blockers, acetylcholine antagonists, on the rate of interaction of acetylcholine esterase with organophosphorus inhibitors.

An increased ethidium bromide fluorescence at 610 nm was observed in the presence of cholinesterases from some natural sources, and a new fluorescence band appeared in the 500–570 nm region. The data obtained suggest a resonance energy transfer from the cholinesterase-ethidium bromide complex to a free ethidium bromide molecule. The structure of the peripheral ligand binding sites in the active center of bovine erythrocyte acetylcholinesterase, horse serum butyrylcholinesterase, and squid ganglia propionylcholinesterase proved essentially similar.

We studied fluorescence of 9-amino-1,2,3,4-tetrahydroacridine hydrochloride (tacrine) in the presence of serum cholinesterase. Quenching of tacrine fluorescence dependent on cholinesterase activity has been revealed. A quenching mechanism is proposed; it includes formation of a complex and charge transfer mediated by excited tacrine molecule as well as indole of tryptophan residue from the periphery of cholinesterase active site.

Enzyme assay is proposed for improving the selectivity of the determination of an organophosphorus (carbamate) insecticide in the presence of a heavy-metal salt in a sample (exemplified by a model system containing proserine and mercuric bromide). The method involves the use of a substrate–indicator system based on acylthiocholine and Ellman's reagent (or its derivative).

The fluorescence intensity of reversible inhibitor ethidium bromide fluorophore complex with equine blood butyryl cholinesterase decreases in the presence of inhibitor (tacrine) not fluorescing in the visible spectrum. An express method for tacrine evaluation is developed.

We present the results of spectral studies of the interactions between butyrylcholinesterase and ethidium bromide fluorophore inhibitor. The ethidium bromide fluorescence selectively increased in the presence of butyrylcholinesterase. A rapid method for evaluation of serum butyrylcholinesterase activity is developed.

Modern views on the structure of cholinesterase active sites and the mechanism of their interaction with organophosphorus inhibitors are considered. The attention is focused on the mechanism of the effect of cholinergic receptor blockers, acetylcholine antagonists, on the rate of interaction of acetylcholine esterase with organophosphorus inhibitors.

Spectral studies of the interaction between amanitine and ethidium bromide fluorophore showed the appearance of a new intensive fluorescence band after addition of amanitine to ethidium bromide solution, caused by the formation of a charge-transfer complex. The new fluorescence band is located in a shorter wave region of the spectrum compared to ethidium bromide fluorescence band. Based on the results, a rapid fluorescent method for detection of amanitines was developed.

An increased ethidium bromide fluorescence at 610 nm was observed in the presence of cholinesterases from some natural sources, and a new fluorescence band appeared in the 500-570 nm region. The data obtained suggest a resonance energy transfer from the cholinesterase-ethidium bromide complex to a free ethidium bromide molecule. The structure of the peripheral ligand binding sites in the active center of bovine erythrocyte acetylcholinesterase, horse serum butyrylcholinesterase, and squid ganglia cholinesterase proved essentially similar.

The peripheral binding site of horse serum cholinesterase (EC 3.1.1.7) for quaternary ligands was investigated by fluorescent probing with the use of ethidium bromide. Spectral evidence for the participation of the tryptophan indole group of the peripheral site of horse serum cholinesterase in the formation of a cholinesterase complex with ethidium bromide is presented. The mechanism of cholinesterase effect on ethidium bromide fluorescence is proposed.

We studied fluorescence of 9-amino-1,2,3,4-tetrahydroacridine hydrochloride (tacrine) in the presence of serum cholinesterase. Quenching of tacrine fluorescence dependent on cholinesterase activity has been revealed. A quenching mechanism is proposed; it includes formation of a complex and charge transfer mediated by excited tacrine molecule as well as indole of tryptophan residue from the periphery of cholinesterase active site.

Fluorescence intensity of thioflavin T fluorogenic label increased significantly as a result of formation of enzyme-inhibitory complex with acetylcholinesterase of human blood erythrocytes. Thioflavin T is a reversible inhibitor, selectively reacting with acetylcholinesterase. Thioflavin T fluorescence intensity is proportional to acetylcholinesterase activity for the studied interval of enzyme activities. A rapid fluorescent method for measuring acetylcholinesterase activity is proposed.

The sensitivity of detection of anticholinesterase compounds (e.g. tacrine) by the biochemical method significantly increased when fluorogenic compound N-(4-(7-diethylamino-4-methylcoumarine-3-yl)phenyl)maleimide was used instead of Ellman's reagent. A kinetic fluorescent method for evaluating cholinesterase inhibitors is proposed.

It has been shown that a fast increase in pH of myosin solution leads to ATP formation de novo from ADP and Pi (about one ATP molecule per one myosin molecule). The obligatory condition for ATP synthesis was that the value of pH 7.9-8.0 should be crossed in the course of pH-jump. The data obtained are explained in terms of the concept of conformational relaxation in enzyme catalysis.