Time filter

Source Type

Terentyev D.A.,Belgian Institute for Nuclear Sciences | Dubinko A.V.,Belgian Institute for Nuclear Sciences | Dubinko V.I.,National Science Center Kharkov Institute of Physics and Technology | Dmitriev S.V.,RAS Institute for Metals Superplasticity Problems | And 2 more authors.
Modelling and Simulation in Materials Science and Engineering | Year: 2015

The interaction of discrete breathers with the primary lattice defects in transition metals such as vacancy, dislocation, and surface is analyzed on the example of bcc iron employing atomistic simulations. Scattering of discrete breathers on the lattice defects induces localized atomic excitations, with intensity and relaxation time depending on the defect structure and breather kinetic energy. The dissipation of the intrinsic breather energy due to the scattering is computed and analyzed. It is concluded that the breather-to-defect energy transfer may stipulate the activation of the lattice defects causing unexpected athermal effects such as enhanced mass transfer or electroplasticity, already experimentally reported but so far not fully understood at the atomic-scale level. © 2015 IOP Publishing Ltd.

Shevkunov S.V.,Peter The Great St Petersburg Polytechnical University
Colloid Journal | Year: 2016

Computer simulation has been employed to study the effect of a confined space of a planar model pore with structureless hydrophobic walls on the hydration of Na+Cl– ion pairs in water vapor at room temperature. A detailed many-body model of intermolecular interactions has been used. The model has been calibrated relative to experimental data on the free energy and enthalpy of the initial reactions of water molecule attachment to ions and the results of quantum-chemical calculations of the geometry and energy of Na+Cl– (H2O)N clusters in stable configurations, as well as spectroscopic data on Na+Cl– dimer vibration frequencies. The free energy and work of hydration, as well as the adsorption curve, have been calculated from the first principles by the bicanonical statistical ensemble method. The dependence of hydration shell size on interionic distance has been calculated by the method of compensation potential. The transition between the states of a contact (CIP) and a solvent-separated ion pair (SSIP) has been reproduced under the conditions of a nanopore. The influence of the pore increases with the hydration shell size and leads to the stabilization of the SSIP states, which are only conditionally stable in bulk water vapor. © 2016, Pleiades Publishing, Ltd.

Tsybin O.,Peter The Great St Petersburg Polytechnical University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

Mechanisms of a fast energetic excitation in a nano-device with an embedded molecular film are discussed herein. Excited intermolecular transport of protons, electrons and other quantum carriers could create communication channels inside a molecular network. We suggest that such channels could be analyzed by means of electron capture dissociation reactions of a protonated peptide, protein or a DNA to reveal the intramolecular pathways of mobile carrier motion in an isolated dehydrated molecule. In general, initial processing stage in a nano-device with a molecular film consists of a target direct activation followed by energy transport from target excitations into a surface molecular film which produces an indirect activation. We analyzed selected indirect molecular excitations produced by a metal or a semiconductor target directly activated by means of a radiofrequency electromagnetic field. Further processing stage after the activation consists of molecular relaxation and transportation phenomena providing nano-electromagnetic field, molecular flow, and communication. © Springer International Publishing Switzerland 2015.

Shevkunov S.V.,Peter The Great St Petersburg Polytechnical University
Russian Journal of Physical Chemistry A | Year: 2016

The hydration of a single-charged chloride anion Cl- in a model plane nanopore with structureless hydrophilic walls in water vapor at room temperature is simulated using the Monte Carlo method. It is established that the adsorption of a fraction of associate molecules Cl-(H2O)N on the walls enhances its thermodynamic stability and simulates the hydration of the ion at low vapor pressures. It is shown that a second stability crisis forms on the curve of the hydration work function in the mode of weak wall hydrophilicity. © 2016, Pleiades Publishing, Ltd.

Lin'kova N.S.,RAS Pavlov Institute of Physiology | Drobintseva A.O.,D O Ott Research Institute Of Obstetrics | Orlova O.A.,St Petersburg Institute Of Bioregulation And Gerontology | Kuznetsova E.P.,Peter The Great St Petersburg Polytechnical University | And 3 more authors.
Bulletin of Experimental Biology and Medicine | Year: 2016

The effect peptides KE, KED, AED and AEDG on proliferation (Ki-67), regeneration and aging (CD98hc), apoptosis (caspase-3), and extracellular matrix remodeling (MMP-9) in skin fibroblasts during their aging in culture were studied by immunofluorescent confocal microscopy. All studied peptides inhibited MMP-9 synthesis that increases during aging of skin fibroblasts and enhanced the expression of Ki-67 and CD98hc that are less intensively synthesized during cell aging. Peptides AED and AEDG suppressed caspase-dependent apoptosis that increases during aging of cell cultures. © 2016, Springer Science+Business Media New York.

Discover hidden collaborations