Shumakovich G.P.,RAS A.N. Bach Institute of Biochemistry |
Vasil'eva I.S.,RAS A.N. Bach Institute of Biochemistry |
Morozova O.V.,RAS A.N. Bach Institute of Biochemistry |
Khomenkov V.G.,RAS A.N. Bach Institute of Biochemistry |
And 6 more authors.
Journal of Applied Polymer Science | Year: 2010
A comparative study of chemical and enzymatic methods of aniline polymerization was carried out. Fungal laccase from Trametes hirsuta was used in the synthesis of polyaniline nanoparticles made with poly(2-acrylamido-2- methyl-1-propanesulfonic acid) (PAMPS). Template polymerization of aniline was carried out in aqueous buffer. It was shown that the laccase had high long-term and operating stabilities under acidic condition favorable for synthesis of conducting polyaniline. UV-vis, FTIR spectroscopy, and cyclic voltammetry analysis are used for the characterization of the polyelectrolyte complexes of polyaniline and PAMPS. The incorporation of the polymeric acid in polyaniline has been demonstrated by atomic force microscopy. The size and morphology of the nanoparticles of the polyaniline-PAMPS complexes depended on the method of the synthesis. A comparison of some physical and chemical properties of water dispersible conducting polyaniline-PAMPS was performed under production by enzymatic and chemical methods. It was found a difference in structures and some physicochemical properties of polyaniline colloids prepared by chemical and laccase-catalyzed methods. © 2010 Wiley Periodicals, Inc.
Sazonova M.A.,Institute of General Pathology and Pathophysiology |
Sinyov V.V.,Russian Cardiology Research and Production Complex |
Barinova V.A.,Russian Cardiology Research and Production Complex |
Ryzhkova A.I.,Ki Skryabin Moscow State Academy Of Veterinary Medicine And Biotechnology |
And 3 more authors.
Experimental and Molecular Pathology | Year: 2015
Mitochondrial genome mutations are associated with different pathologies. Earlier the authors of the study found an association of some mitochondrial genome mutations with atherosclerosis. In the present study, an attempt to analyze a connection of detected mutations with the age of patients with atherosclerosis was made. The investigated sample included 700 individuals, examined by ultrasonography in polyclinics of Moscow and the Moscow region. The sample was divided approximately into two equal parts. The first part included patients with carotid atherosclerosis. The second part included conventionally healthy study participants. In PCR-fragments of individuals' DNA the heteroplasmy level of investigated mutations was quantitatively measured by the method, developed by members of our laboratory on the basis of pyrosequencing technology. According to the obtained results mutations G12315A, G14459A and G15059A were significantly associated with the age of the study participants. The same time one nucleotide replacements A1555G and G14846A correlated negatively with the age at a high level of significance. Thus, in the present study an association of atherogenic mitochondrial genome mutations with age was found. Antiatherogenic mutations were correlated with the age negatively. This prompts a suggestion about common mechanisms of atherogenesis and aging. © 2015 Elsevier Inc.
Tsarkova M.S.,Ki Skryabin Moscow State Academy Of Veterinary Medicine And Biotechnology |
Zaitsev S.Y.,Ki Skryabin Moscow State Academy Of Veterinary Medicine And Biotechnology |
Zaitsev I.S.,Ki Skryabin Moscow State Academy Of Veterinary Medicine And Biotechnology |
Krutikov A.A.,Kazan Federal University |
Shtyrlin V.G.,Kazan Federal University
Macroheterocycles | Year: 2014
The preparation of compositions comprising multifunctional compound is one of the key directions for design of chemosensoring materials that are important for the determination of particular ions in solutions. These compounds are characterized by ionophoric and photosensitive parts with reliable optical response and ion-selectivity. Their structures suggest the possibility of the complex formation with particular metal cations. The main goals of this study are as following: a) to investigate the absorption spectra of the novel derivative of the dithiacrown ethers (DTCE), synthesized in the laboratory of Professor S.P. Gromov (Photochemistry Center RAS), both: in salt solutions and in monolayers; b) to study the DTCE interaction with various metal cations, including mercury, as well as to carry out quantum-chemical calculations of their possible complexes. Spectral characteristics were examined in the DTCE acetonitrile solutions and their changes in the presence of some cations were found. The pronounced changes were obtained in the case of Hg2+ which are expressed as a hypsochromic shift on 22 nm. Absorption spectra of aqueous solutions of DTCE and perchlorates of alkali, alkaline earth, and heavy metals (lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, copper, zinc, lead, cadmium, and mercury) at various concentrations were obtained. When the DTCE concentration equals to 10–5 M, the absorption intensity is low, and DTCE absorption maximum shifts in the presence of all the salts are rather small. The greatest shift (by 6 nm) of the DTCE absorption maximum to shorter wavelengths was observed for the mercury(II) perchlorate only. In order to select the DTCE concentration for further research the spectral dependence of the optical density vs. DTCE concentration was obtained (10 M was the most appropriate value of the DTCE concentration). Based on these results the DTCE extinction coefficient in aqueous solutions was determined (ε = 9329 M–1cm–1). Assuming the formation of the DTCE-cation complexes as 1:1, the metal perchlorates with lack and excess of the cations in the aqueous solutions were chosen. The absorption spectra had minor differences at DTCE concentration of 10–4 M and metal perchlorates concentration of 10–5 M (lack of the metal cations). Maximum hypsochromic shift by 4 nm was observed in the presence of mercury(II) perchlorate. It appeared that the lack of concentration of the metal salt does not allow the formation of complexes between the crown ether ring and a cation. The absorption intensity in the presence of most of salts was slightly reduced up to 85–95 % from baseline. The absorption spectra showed significant shifts of the absorption maxima to shorter wavelengths by 29 nm only in the presence of mercury(II) perchlorate at high concentrations (10–3 M). This fact proves a DTCE selectivity for mercury(II) cation. Moreover, the value of the shift depends on the salt concentration. An additional confirmation of these results was obtained in the study of the absorption spectra of the DTCE monolayers transferred from bidistilled water and aqueous solutions of Hg(ClO4)2 at constant surface pressure (about 10 mN/m). In all cases, the broad absorption maxima in the region of 350–450 nm were found. The main feature was that the maximum absorption for DTCE monolayer transferred to 10–5 M solution of Hg(ClO4)2 was 0.00575 a.u. at 406 nm. This is by 209% higher than those for the DTCE monolayer transferred from the water. Thus, the shift of the absorption maximum of DTCE monolayer in the presence of mercury salt was 23 nm to shorter wavelengths. This is further evidence of complex formation between DTCE (in monolayer) and mercury(II) cations from the aqueous subphase. For visualization and confirmation of the possibility of complex formation between DTCE and mercury(II) cation the quantum-chemical calculations of their structural models were carried out. The total energy of the optimized structure of the complex between DTCE cation and mercury(II) (with 2 perchlorate counter-anions) is set to E0 = –565.1231 a.u. It can be compared with the energies of individual species: the DTCE cation (E0 = –250.5477 a.u.) and Hg(ClO4)2 (E0 = –314.4877 a.u.). Thus, the change in energy (ΔE) upon complex formation is about –0.0877 a.u. (–230 kJ/mol). High energy of complex formation and high covalency of the Hg–S bonds explain the significant blue shift of the maximum in the absorption spectra of the solutions of DTCE with Hg(ClO4)2. © ISUCT Publishing.