Lobachevsky University

Nizhniy Novgorod, Russia

Lobachevsky University

Nizhniy Novgorod, Russia

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Knyazev A.V.,Lobachevsky University | Somov N.V.,Lobachevsky University | Shipilova A.S.,Lobachevsky University | Gusarova E.V.,Lobachevsky University | And 3 more authors.
Journal of Molecular Structure | Year: 2017

The crystal structures of methylprednisolone aceponate were determined by X-ray diffraction analysis at temperatures 90 K and 150 K: space group P212121, a = 14.8592(2), b = 19.6844(5), c = 26.1626(4) Å, Z = 12; R = 0.0598 (T = 90 K); space group P212121, a = 6.57348(14), b = 14.8295(3), c = 26.2214(5) Å, Z = 4; R = 0.0518 (T = 150 K). Features of structural changes in the phase transition were revealed. The abrupt change in the unit cell parameters in the phase transition was shown by low-temperature X-ray powder. The methods of degree of invariance of crystal electron density and molecular Voronoi−Dirichlet polyhedra were used for the analysis of polymorphism in methylprednisolone aceponate. The atomic structure at 90 K have a translational pseudosymmetry of electron density η = 0.329(1). The decrease of number of intermolecular contacts in the high-temperature modification due to rupture of intermolecular non-valence contacts C/O was observed. © 2017 Elsevier B.V.

Sokolova E.,RAS Shemyakin Ovchinnikov Institute of Bioorganic Chemistry | Guryev E.,Lobachevsky University | Yudintsev A.,Lobachevsky University | Vodeneev V.,Lobachevsky University | And 2 more authors.
Oncotarget | Year: 2017

Immunotoxin 4D5scFv-PE40 is a recombinant protein that comprises 4D5scFv antibody as a targeting module and fragment of Pseudomonas exotoxin A as an effector (toxic) one. The immunotoxin has shown pronounced antitumor effect on cancer cells overexpressing HER2 receptor in vitro and on HER2-positive experimental tumors in vivo. We clarified the mechanism of 4D5scFv-PE40 activity that is of particular importance in the case of targeted therapeutic agent aimed at personalizing treatment of disease in relation to molecular genetic characteristics of each patient. After specific binding to HER2 on the cell surface and clathrin-mediated endocytosis the immunotoxin passes through retrograde trafficking route. During this route the immunotoxin molecule is supposed to undergo enzymatic processing that ends in separation of C-terminal and N-terminal fragments of the immunotoxin. Finally, C-terminal functionally active fragment of 4D5scFv-PE40 arrests protein synthesis in cytoplasm followed by cell death via apoptosis.

Es'kin V.A.,Lobachevsky University | Ivoninsky A.V.,Lobachevsky University | Kudrin A.V.,Lobachevsky University | Popova L.L.,Lobachevsky University
Journal of Experimental and Theoretical Physics | Year: 2017

Electromagnetic radiation from filamentary electric-dipole and magnetic-current sources of infinite length in the presence of gyrotropic cylindrical scatterers in the surrounding free space is studied. The scatterers are assumed to be infinitely long, axially magnetized circular plasma columns parallel to the axis of the filamentary source. The field and the radiation pattern of each source are calculated in the case where the source frequency is equal to one of the surface plasmon resonance frequencies of the cylindrical scatterers. It is shown that the presence of even a single resonant magnetized plasma scatterer of small electrical radius or a few such scatterers significantly affects the total fields of the filamentary sources, so that their radiation patterns become essentially different from those in the absence of scatterers or the presence of isotropic scatterers of the same shape and size. It is concluded that the radiation characteristics of the considered sources can efficiently be controlled using their resonance interaction with the neighboring gyrotropic scatterers. © 2017, Pleiades Publishing, Inc.

Perova T.V.,Lobachevsky University | Kustov T.V.,Saint Petersburg Electrotechnical University l
2015 4th Forum Strategic Partnership of Universities and Enterprises of Hi-Tech Branches (Science. Education. Innovation) | Year: 2015

The article deals with the most current students' career development and employment promotion technologies. The paper describes the experience of the career center Lobachevsky university. The structure and main activities of the student council's Potential activity of the Career Centre. © 2015 IEEE.

Buntov E.,Ural Federal University | Zatsepin A.,Ural Federal University | Slesarev A.,Ural Federal University | Mikhailovich A.,Ural Federal University | Mikhaylov A.,Lobachevsky University
Physica Status Solidi (A) Applications and Materials Science | Year: 2015

SiO2 films, grown on a Si substrate and implanted with Li, Na, and K ions were studied by means of optically stimulated electron emission spectroscopy (OSEE). Interference effects of exciting light were observed in OSEE spectra. Application of original normalization technique allowed to compensate interference fringes in the experimental results. Three categories of defect states were identified and studied: intrinsic luminescent, emission-active silica defect centers, and implanted cation-related localized states. © 2015 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim.

PubMed | Lobachevsky University and RAS Institute of Macromolecular Compounds
Type: | Journal: Journal of biophotonics | Year: 2016

Efficient drug delivery can be assigned to tasks that attract the most acute attention of researchers in the field of anticancer drug design. We have reported the first case of using amphiphilic polymer brushes as nanocontainers for photosensitizer delivery to cancer cells. Regular graft-copolymers of hydrophobic polyimides with hydrophilic polymethacrylic acid side chains were loaded with photosensitive dye tetra(4-fluorophenyl)tetracyanoporphyrazine (Pz) providing a sufficiently stable homogeneous fraction of fluorescent Pz-loaded nanoparticles with a size of 100-150 nm. Pz-loaded polymer brushes were substantially more efficient for Pz delivery into cells compared with other types of particles examined, Pz-polyethyleneglycol and Pz-methylcellulose. In vivo, an efficient Pz delivery to tumor can also be expected since the Pz-PB particle size is in the optimal range for passive targeting. Pz-PB showed pronounced photodynamic activity, while, that is important, in the absence of irradiation the PB carrier itself was significantly less toxic than the dye itself. Summing up, water-soluble polymer brushes with polyimide backbones and polymethacrylic acid side chains can be regarded as a novel type of nanocontainers providing efficient intracellular drug delivery for photodynamic therapy of cancers.

Agrba P.D.,Lobachevsky University | Kirillin M.Y.,RAS Institute of Applied Physics
Photonics and Lasers in Medicine | Year: 2016

Optical coherence tomography (OCT) is a modern technique for imaging of internal structures of biotissue of up to several millimeters in depth with a resolution of several micrometers. However, various external conditions can distort the diagnostic capabilities of an OCT image. Mechanical compression and temperature regime are the two conditions which mostly affect the diagnostic OCT images obtained with a contact probe. It is shown here that the application of compression to human skin induces a decrease in contrast of the stratum corneum-epidermis junction and an increase in contrast of the epidermis-dermis junction. With regard to these junctions, a preliminary change of biotissue temperature induces additional changes in the contrast, with opposing effects in case of heating and cooling. © 2016 by De Gruyter 2016.

Konakov A.A.,Lobachevsky University | Filatov D.O.,Lobachevsky University | Korolev D.S.,Lobachevsky University | Belov A.I.,Lobachevsky University | And 3 more authors.
AIP Advances | Year: 2016

Using the envelope-function approximation, the single-particle states of electrons and holes in spherical GaN nanocrystals embedded in different amorphous dielectric matrices (SiO2, Al2O3, HfO2 and Si3N4) have been calculated. Ground state energies of electrons and holes in GaN nanocrystals are determined using the isotropic approximation of the k · p -Hamiltonian. All the ground state energies are found to increase with lowering the nanocrystal size and are proportional to the R-n, where R is the nanocrystal radius, n =1.5-1.9 for electrons and 1.7-2.0 for holes. The optical gap of GaN nanocrystals changes from 3.8 to 5 eV for the nanocrystal radius ranging from 3 to 1 nm. © 2016 Author(s).

Kudrin A.V.,Lobachevsky University | Kudrina O.A.,Lobachevsky University | Petrov E.Y.,Lobachevsky University
Journal of Experimental and Theoretical Physics | Year: 2016

We consider electromagnetic nonlinear normal modes in cylindrical cavity resonators filled with a nonlinear nondispersive medium. The key feature of the analysis is that exact analytic solutions of the nonlinear field equations are employed to study the mode properties in detail. Based on such a nonperturbative approach, we rigorously prove that the total energy of free nonlinear oscillations in a distributed conservative system, such as that considered in our work, can exactly coincide with the sum of energies of the normal modes of the system. This fact implies that the energy orthogonality property, which has so far been known to hold only for linear oscillations and fields, can also be observed in a nonlinear oscillatory system. © 2016, Pleiades Publishing, Inc.

Bareev D.D.,Lobachevsky University | Gavrilenko V.G.,Lobachevsky University | Grach S.M.,Lobachevsky University | Sergeev E.N.,Lobachevsky University
Advances in Space Research | Year: 2016

It is shown experimentally that the relaxation time of the stimulated electromagnetic emission (SEE) after the pump wave turn off decreases when frequency of the electromagnetic wave, responsible for the SEE generation (pump wave f0 or diagnostic wave fdw) approaches 4th harmonic of the electron cyclotron frequency fce. Since the SEE relaxation is determined by the damping rate of plasma waves with the same frequency, responsible for the SEE generation, we calculated damping rates of plasma waves with ω∼ωuh (ω is the plasma wave frequency, ωuh is the upper hybrid frequency) for frequencies close to and distant from the double resonance where ωuh∼4ωce (ωce=2πfce). The calculations were performed numerically on the base of linear plasma wave dispersion relation at arbitrary ratio between |Δ|=ω-4ωce and |k|||VTe (VTe is the electron thermal speed and k|| is the projection of the wave vector onto the magnetic field direction. A comparison of calculation and experimental results has shown that obtained frequency dependence of the SEE decay rate is similar to the damping rate frequency dependence for plasma waves with wave vectors directed at the angles 60-70° to the magnetic field, and gives a strong hint that oblique upper hybrid plasma waves should be responsible for the SEE generation. © 2015 COSPAR.

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