Formirovanie poverhnostnih sloev pri lasernoij naplavke s ispolzovaniem moshhnih volokonnih lazerov

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The study of antimicrobial activity of stonecrop extracts (Sedum maximum (L.) Hoffm., S. telephium I.)

The purpose of the work is to investigate the antimicrobial activity of aqueous alcoholic extract of large stonecrop and purple stonecrop. Material and Methods. The effects of large stonecrop (Sedum maximum (L.) Hoffm.) and purple stonecrop (S. telepium L.) on aqueous solution of alcoholic extracts on Staphylococcus aureus АТС С 209R, Pseu-domonas aeruginosa ATCC 27835, Escherichia coli ATCC 25922 have been studied by the method of double serial dilution followed by seeding on solid culture media. As a result of the work the minimum inhibitory concentrations for all extracts to all the studied cultures have been found. Stonecrop extracts have bactericidal action. Conclusion. Antimicrobial activity has been determined for the extracts of both species for all researched samples of microbial strains

Reactions of 7-nitropyrido[1,2-a]benzimidazolium salts with hydrazines and hydroxylamine

We are the first to show that quaternary 7-nitropyrido[1,2-a] benzimidazolium salts are cleaved by hydrazine, phenylhydrazine, and hydroxylamine to form 2-pyrazolinemethyl- and 2-isoxazoline-methyl-6- nitrobenzimidazoles. © 2010 Springer Science+Business Media, Inc

Reactions of 7-nitropyrido[1,2-a]benzimidazolium salts with hydrazines and hydroxylamine

We are the first to show that quaternary 7-nitropyrido[1,2-a] benzimidazolium salts are cleaved by hydrazine, phenylhydrazine, and hydroxylamine to form 2-pyrazolinemethyl- and 2-isoxazoline-methyl-6- nitrobenzimidazoles. © 2010 Springer Science+Business Media, Inc

Plasma methionine depletion and pharmacokinetic properties in mice of methionine γ-lyase from Citrobacter freundii, Clostridium tetani and Clostridium sporogenes

PK studies were carried out after a single i.v. administration of 500 and 1000 U/kg by measuring of MGL activity in plasma samples. L-methionine concentration was measured by mass spectrometry. After single i.v. injection of 500 U/kg the circulating T1/2 of enzymes in mice varies from 73 to 123 min. The AUC0-tinf values determined for MGL 500 U/kg from C. freundii, C. tetani and C. sporogenes are 8.21 ± 0.28, 9.04 ± 0.33 and 13.88 ± 0.39 U/(ml × h), respectively. Comparison of PK parameters of three MGL sources in the dose of 500 U/kg indicated the MGL C. sporogenes to have better PK parameters: clearance 0.83(95%CI: 0.779–0.871) – was lower than C. tetanii 1.27(95%CI: 1.18–1.36) and C. freundii 1.39(95%CI: 1.30–1.49). Mice plasma methionine decreased to undetectable level 10 min after MGL 1000 U/kg injection. After MGL C. sporogenes 500 U/kg injection plasma methionine level completely omitted after 10 min till 6 h, assuming the sustainability of negligible levels of methionine ( < 5 μM) in plasma of mice for about 6 h. The recovery of methionine concentration showed the advantageous efficiency of MGL from C. sporogenes: 95% 0.010–0.022 vs 0.023–0.061 for MGL C. freundii and 0.036–0.056 for MGL C. tetani. There are no significant differences between methionine cleavage after MGL C. tetani and MGL C. sporogenes i.v. injection at all doses. MGL from C. sporogenes may be considered as promising enzyme for further investigation as potential anticancer agent. © 2017 Elsevier Masson SA

Plasma methionine depletion and pharmacokinetic properties in mice of methionine γ-lyase from Citrobacter freundii, Clostridium tetani and Clostridium sporogenes

PK studies were carried out after a single i.v. administration of 500 and 1000 U/kg by measuring of MGL activity in plasma samples. L-methionine concentration was measured by mass spectrometry. After single i.v. injection of 500 U/kg the circulating T1/2 of enzymes in mice varies from 73 to 123 min. The AUC0-tinf values determined for MGL 500 U/kg from C. freundii, C. tetani and C. sporogenes are 8.21 ± 0.28, 9.04 ± 0.33 and 13.88 ± 0.39 U/(ml × h), respectively. Comparison of PK parameters of three MGL sources in the dose of 500 U/kg indicated the MGL C. sporogenes to have better PK parameters: clearance 0.83(95%CI: 0.779–0.871) – was lower than C. tetanii 1.27(95%CI: 1.18–1.36) and C. freundii 1.39(95%CI: 1.30–1.49). Mice plasma methionine decreased to undetectable level 10 min after MGL 1000 U/kg injection. After MGL C. sporogenes 500 U/kg injection plasma methionine level completely omitted after 10 min till 6 h, assuming the sustainability of negligible levels of methionine ( < 5 μM) in plasma of mice for about 6 h. The recovery of methionine concentration showed the advantageous efficiency of MGL from C. sporogenes: 95% 0.010–0.022 vs 0.023–0.061 for MGL C. freundii and 0.036–0.056 for MGL C. tetani. There are no significant differences between methionine cleavage after MGL C. tetani and MGL C. sporogenes i.v. injection at all doses. MGL from C. sporogenes may be considered as promising enzyme for further investigation as potential anticancer agent. © 2017 Elsevier Masson SA

Molecular properties of hybrid macromolecular antioxidants: Dextran hydrophobically modified by sterically hindered phenols

The conformation properties of clinically relevant hybrid macromolecular antioxidants (dextran hydrophobically modified by sterically hindered phenols) in aqueous solution were characterized by a combination of dynamic light scattering (DLS), size exclusion chromatography (SEC), and small-angle neutron scattering (SANS). We were able to split and analyze separately two different types of polydispersity —polydispersity over molecular weights and the one over substitution degree. The properties of the hybrid macromolecules are determined by the number of hydrophobic antioxidants in a single molecule. An insertion of hydrophobic groups into a hydrophilic chain changes the conformation of a single conjugate macromolecule. We have established that with the increasing of a number of hydrophobic antioxidant groups, a conformational transition occurs where a single conjugate undergoes a transition from a Gaussian coil conformation to a more compact structure

1-R-2-[(1E,3E)-4-Aminobuta-1,3-dien-1-yl]-1H-benzimidazoles. Synthesis and some transformations

7-Nitropyridobenzimidazolium salts are cleaved with secondary amines to form 2-[(E,E)-4-aminobuta-1,3-dienyl]-1H-benzimidazoles. The latter react with dimethyl acetylene-dicarboxylate to yield 4a-[(E,Z,E)-6-amino-4,5- dimethoxycarbonylhexa-1,3,5-trien-1-yl]-1,2,3,4-tetra(methoxycarbonyl)-4a, 5-dihydropyrido[1,2-a]benzimidazoles. © 2010 Springer Science+Business Media, Inc

1-R-2-[(1E,3E)-4-Aminobuta-1,3-dien-1-yl]-1H-benzimidazoles. Synthesis and some transformations

7-Nitropyridobenzimidazolium salts are cleaved with secondary amines to form 2-[(E,E)-4-aminobuta-1,3-dienyl]-1H-benzimidazoles. The latter react with dimethyl acetylene-dicarboxylate to yield 4a-[(E,Z,E)-6-amino-4,5- dimethoxycarbonylhexa-1,3,5-trien-1-yl]-1,2,3,4-tetra(methoxycarbonyl)-4a, 5-dihydropyrido[1,2-a]benzimidazoles. © 2010 Springer Science+Business Media, Inc