Formation of High-quality Aluminum Oxide under Ion Beam Irradiation

In this work we used the radiation–induced technique of selective association of atoms (SAA) to create the aluminum oxide layer on the surface of metallic Al under oxygen ion beam irradiation. Optimal conditions for carrying out the radiation-induced aluminum oxidation process were established to minimize the target sputtering. An aluminum oxide layer of 20 nm thickness was obtained after irradiation of aluminum target with oxygen ions with 0.2 keV energy up to a dose of ∼2.6 ⋅ 1018 ions/cm2 at room temperature. HRTEM and EELS techniques were used to characterize the chemical compositional changes after irradiation. It was found that aluminum oxide layer after irradiation contained an excessive amount (∼10 at.%) of implanted oxygen. Keywords: ion beam irradiation, aluminum thin films, EELS, HRTE

Glycyrrhetinic acid and its derivatives as inhibitors of poly(ADP-ribose)polymerases 1 and 2, apurinic/apyrimidinic endonuclease 1 and DNA polymerase β

Aim. For strengthening the efficiency of monofunctional alkylating antineoplastic drugs it is important to lower the capacity of base excision repair (BER) system which corrects the majority of DNA damages caused by these reagents. The objective was to create inhibitors of the key BER enzymes (PARP1, PARP2, DNA polymerase β, and APE1) by the directed modification of glycyrrhetinic acid (GA). Methods. Amides of GA were produced from the GA acetate by formation of the corresponding acyl chloride, amidation with the appropriate amine and subsequent deacylation. Small library of 2-cyano substituted derivatives of GA methyl esters was obtained by the structural modification of GA framework and carboxylic acid group. The inhibitory capacity of the compounds was estimated by comparison of the enzyme activities in specific tests in the presence of compounds versus their absence. Results. None of tested compounds inhibits PARP1 significantly. Unmodified GA and its morpholinic derivative were shown to be weak inhibitors of PARP2. The derivatives of GA containing keto-group in 11 triterpene framework were shown to be moderate inhibitors of pol β. Compound 3, containing 12-oxo-9(11)-en moiety in the ring C, was shown to be a single inhibitor of APE1 among all compounds studied. Conclusions. The class of GA derivatives, selective pol β inhibitors, was found out. The selective inhibitor of APE1 and weak selective inhibitor of PARP2 were also revealed

Creation of thin superconducting MoCN covering by cathode sputtering technique as a basis film for functional cryogenic nanoelements

The work was supported by the NRC “Kurchatov Institute” (№1639)

The rotation curve and mass-distribution in highly flattened galaxies

A new method is developed which permits the reconstruction of the surface-density distribution in the galactic disk of finite radius from an arbitrary smooth distribution of the angular velocity via two simple quadratures. The existence of upper limits for disk's mass and radius during the analytic continuation of rotation curves into the hidden (non-radiating) part of the disk is demonstrated.Comment: 13 pages, 2 figure

Low temperature resistive elements integrated into superconductive NbN nanowires produced under ion beam irradiation

The work was supported by the NRC “Kurchatov Institute” (№1639)

Collapse of Incoherent Light Beams in Inertial Bulk Kerr Media

We use the coherent density function theory to show that partially coherent beams are unstable and may collapse in inertial bulk Kerr media. The threshold power for collapse, and its dependence on the degree of coherence, is found analytically and checked numerically. The internal dynamics of the walk-off modes is illustrated for collapsing and diffracting partially coherent beams