45 research outputs found

    Stable σh-adducts in the reactions of the acridinium cation with heterocyclic N-nucleophiles

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    A reaction of NH-heterocycles with the 10-methylacridinium cation in the presence of a base led to 9,10-dihydro-10-methyl-9-substituted acridines, which can be considered as stable intermediates in the aromatic nucleophilic substitution reaction of hydrogen. The structure of the intermediates was studied and their oxidation potentials were determined. Generally, the oxidation potential was found to symbatically change with the changes in the energy of HOMO. © 2013 Springer Science+Business Media New York

    Structural and functional indicators of the heart of patients with ischemic heart disease and type 2 diabetes mellitus. Rhythmoinotropic response isolated myocardium at different levels of glycated hemoglobin

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    BACKGROUND: Adequate glycemic control can significantly reduce the risk of developing cardiovascular events. However, until now, glycaemic targets in aged patients remain a subject of discussion, especially in the conditions of the combined development of Type 2 Diabetes Mellitus (T2DM) and ischemic heart disease (IHD).AIMS: To examine the structural and functional heart parameters in patients with IHD associated with T2DM and the rhythmoinotropic responses of their isolated myocardium depending on glycated hemoglobin level.MATERIALS AND METHODS: The study included 44 patients with a diagnosis of "chronic IHD associated with T2DM", of which 2 groups were formed. Patients with glycated hemoglobin level (HbA1c) <8% were included in the 1st group, and patients with HbA1c ≥8% were included in the 2nd group. The structural and functional heart parameters obtained with ultrasonography, and the rhythmoinotropic responses of myocardium in patients ex vivo were analyzed using the right atrial appendage fragments obtained during elective coronary artery bypass graft. The inotropic response of muscle strips at a basic stimulation frequency of 0,5 Hz to testing influences was assessed. An extrasystolic test and post-rest test were performed.RESULTS: It was found that extrasystolic contractions of isolated myocardial strips in patients of the 2nd group appeared at shorter extrasystolic intervals, which indicates a greater excitability of the myocardium in patients of this group. Postextrasystolic muscle contractions in patients of the 2nd group had significant potentiation. The amplitude of the muscle strips contractions in patients of both groups was potentiative after short rest periods. However, with an increase in the rest duration, potentiation of contractions was observed only in the group with a higher HbA1c level. According to the ultrasonography data, it was found that the values of the endsystolic and diastolic volumes, the interventricular septum thickness and the left ventricular (LV) myocardium mass were significantly lower in the patients of the 1st group compared with the corresponding indicators in the patients of the 2nd group. The early LV filling velocity (peak E) was significantly lower in the patients of the 1st group, which indicates a slower LV relaxation. At the same time, the rapid LV filling velocity did not have a significant intergroup difference, but this indicator exceeded the reference values in both groups.CONCLUSIONS: With a moderately increased glycemic level (9,2 [8,0; 10,3]%), the structural and functional heart parameters are preserved both at the level of the isolated myocardial tissue and at the level of the whole heart

    Surface decoration of silica nanoparticles by Pd(0) deposition for catalytic application in aqueous solutions

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    © 2015 Elsevier B.V.. The work introduces chemical and electrochemical synthetic routes to obtain Pd(0) nanoparticles (PdNPs) deposited onto silica supports in aqueous media. The former route is performed through reduction of Na2[PdCl4] by ascorbic acid in the presence of amino-modified silica nanoparticles (SiO2-NH2). The time-dependent variation of pH and the reductant concentration is the simple synthetic route to get uniform deposition of 215nm sized silica supports by Pd(0) nanoparticles (3-10nm). The methylviologen-mediated electrochemical synthetic route results in small PdNPs (3-9nm) located both onto and beyond the silica supports. Thus, the chemical synthetic route provides more homogeneous Pd(0)-SiO2-NH2 aqueous colloids. The results reveal that attractive interactions of amino/ammonium groups of SiO2-NH2 with both [PdCl4]2- and ascorbate-stabilized Pd(0) seeds are the key reasons for the better Pd(0)-deposition onto silica supports. The chemically deposited Pd(0)-SiO2-NH2 nanoparticles catalyze the chemiluminescence of luminol resulted from the H2O2-facilitated oxidation in alkaline aqueous solutions

    BACTERIAL AND FUNGAL PATHOGENS IN THE TRANSPLANTATION AND DIALYSIS CENTER. ANALYSIS FOR EIGHTEEN YEARS (1998–2015)

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    Aim: to analyze the dynamics of the microflora and its sensitivity to antibiotics in patients of dialysis and transplantation center.Materials and methods. We have examined the bacteriological test results of 1282 patients with chronic kidney disease, stage 5 (renal transplant recipients and dialysis patients) in 1998–2015: 1998–2003 («2003» period), 2008–2011 («2011» period) and 2012–2015 («2015» period). Biomaterial: urine, blood, wound effluent, sputum.Results. The incidence (share of all samples) of gram «–», gram «+» and fungi was 38, 56, 7% for «2003» period; 48, 69, 13% for «2011» period; 61, 54, 18% for «2015» period. The incidence of gram «–» in blood has significantly increased: 22% in «2003», 13% in «2011», and 45% in «2015», respectively. The incidence of Candida fungi is growing in sputum and urine: 15, 33, 41% and 8, 14, 18% (in 2003, 2011, 2015 respectively). The species composition of the fl ora has also significantly changed. In «2003» the shares of Staphylococcus spp. and Enterococcus spp. were 50 and 33%, in «2015» – 34 and 53% respectively. The shares of E. coli, Klebsiella spp., P. aeruginosa and Acinetobacter spp. were in «2003» 32, 21, 15, 11% respectively, and in «2015» – 17, 32, 9, 22%, respectively. The share of a «problem» genus of Candida: C. glabrata and C. krusei has significantly increased. Their combined share increased from 26 to 38% (2003–2015). There was a significant increase in antibiotic resistance, which is mostly pronounced in Enterococcus spp., Klebsiella spp. and Acinetobacter spp. All gram «+» bacteria in «2003» were susceptible to vancomycin and linezolid, but in «2015» 6% of Enterococcus were resistant to vancomycin. Conclusion. Bacterial profile has significantly changed. Regular analysis of the bacterial fl ora is necessary due to the growing antibiotic resistance
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