Quantitative structure-affinity relationship of 5-HT1A receptor ligands by the classification tree method

The influence of molecular structure of 346 ligands on their affinity for 5-HT1A receptors was investigated. It was shown that the effectiveness of the proposed novel approach for interpretation of decision tree models compared favourably with the PLS method. In the context of the proposed approach, molecular fragments and their values of the relative influence on the affinity for 5-HT1A receptors were defined.     

Novel enhanced applications of QSPR models: Temperature dependence of aqueous solubility

A model developed to predict aqueous solubility at different temperatures has been proposed based on quantitative structure–property relationships (QSPR) methodology. The prediction consists of two steps. The first one predicts the value of k parameter in the linear equation , where S_w is the value of solubility and T is the value of temperature. The second step uses Random Forest technique to create high‐efficiency QSPR model. The performance of the model is assessed using cross‐validation and external test set prediction. Predictive capacity of developed model is compared with COSMO‐RS approximation, which has quantum chemical and thermodynamic foundations. The comparison shows slightly better prediction ability for the QSPR model presented in this publication. © 2016 Wiley Periodicals, Inc.     

Experimental investigation of the dielectric strength of the H 011 and E 111 oscillation modes in a cylindrical resonator using compressed gas

It is shown experimentally that in order to increase the stored energy in storage resonators using compressed gas, it is preferable to have oscillation modes in which the electrical components of the fields do not interact with the inner surfaces of the resonator. Zh. Tekh. Fiz. 68, 98–100 (December 1998)     

Features of charge density waves in quasi-one-dimensional conductors at low temperatures

The reported study of charge density waves at low temperatures is based on a microscopic theory. One feature of a charge density wave at low temperatures is a large shift in the chemical potential near its defects, such as solitons, dislocations, and pinning centers, which leads to a higher conductivity of material along chains when the charge density wave is immobile, and the wave dynamics is controlled by this shift. Equations describing the dynamics of a charge density wave have been derived and used to estimate the velocity of 2π-solitons along conducting chains. The resulting soliton mobility has proved to be low and makes a small contribution to the conductivity. The large shift in the chemical potential near strong pinning centers can lead to a considerable increase in linear conductivity along conducting chains. Zh. éksp. Teor. Fiz. 111, 1494–1512 (April 1997)     

Formation of nanosecond RF pulses in an autogenerator by resonance compression of microwave energy

We study the possibility of forming powerful nanosecond rf pulses by accumulation of electromagnetic field energy in the autogenerator oscillatory circuit, followed by a rapid extraction of this energy to an external load. The pulse generation in a monotron is considered as an example. A functional link between the electrophysical characteristics of the autogenerator oscillating system and the parameters of the output rf pulses is established. The efficiency and gain of such devices are analyzed. Institute of Nuclear Physics of the Polytechnical University, Tomsk, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 7, pp. 913–925, July, 1998.     

Novel natural peptides from Hyla arborea schelkownikowi skin secretion

Hyla arborea schelkownikowi is one of the leaf frog species inhabiting the southern territories of Russia and the former USSR. This frog species is a member of the Hylidae Rafinesque, 1815 batrachians family. The present study deals with the previously uninvestigated peptidome of the Hyla arborea schelkownikowi skin secretion. Nano‐electrospray ionization Fourier transform mass spectrometry (nanoESI‐FTMS) of the skin secretion, in the intact form and after acetylation, was selected as the general method of analysis. Electron‐capture dissociation (ECD) and collision‐induced dissociation (CID) fragmentation were both employed, while de novo sequencing was performed by manual interpretation of the MS data. The suppression of the cyclization of b‐ions in the mass spectrometer by the acetylation reaction proved to be very efficient for the de novo sequencing of short peptides. Ten skin peptides were found and all of them, except for bradykinin, had not previously been reported. Six of the peptides belong to the tryptophyllins and related peptides, while three peptides are similar to the aureins. Copyright © 2010 John Wiley & Sons, Ltd.     

Energy extraction from an oversized cavity through a package of interference switches with summation of the output signals

It was shown experimentally that the pulse power output of a resonant microwave compressor with an oversized cavity and an interference switch used for energy extraction could be increased using a package of interference switches with summation of the output signals instead of a single switch. The use of two switches for energy extraction provided an almost twofold increase in the output signal power and a corresponding (almost twofold) decrease in the signal duration. It is shown that energy extraction through four switches with signal summation is possible.