Vol. 51 No. 3 (244) (2017)

Densities and viscosities of diethyl sulfoxide–acetonitrile binary mixtures have been measured over the full range of compositions at temperatures from 298.15 to 323.15 K. Excess molar volumes, apparent molar volumes, partial molar volumes, excess partial molar volumes, partial molar volumes at infinite dilution and thermal expansion coefficients for binary liquid mixtures were calculated. The excess molar volumes are negative over the whole range of composition and become more negative with increasing temperatures from 298.15 to 323.15 K. Viscosity deviations and excess Gibbs energy of viscous flow activation were calculated. The viscosity deviations are negative, but contrary to the excess molar volumes deviations in viscosity become less negative with increasing temperatures. The excess molar volumes and viscosity deviations were correlated by Redlich–Kister equation. Results are discussed in terms of molecular interactions and molecular size and shape in these binary mixtures. The obtained results were interpreted on the basis of dipole-dipole interaction between polar groups of diethyl sulfoxide and acetonitrile.

The synthesis of new 1,2,3-triazoles has been actualized by means of the reaction of dipolar1,3-cycloaddition of organic azides to the $\gamma$-lactones containing terminal triple bond. The synthesized compounds previously were nondescript in literature. High yields of the final products ensured the optimal reaction conditions. 

Тhe antioxidant activity (AOA) and phenolic content of Hypholoma fasciculare, Agaricus bisporus, Pleurotus ostreatus, Trichaptum abietinum, Polyporus squamosus, Schizophyllum commune fungi were investigated. The change in ORP value of [Fe(CN)₆]^3–/[Fe(CN)₆]^4– mediatory system was used to detect AOA. Results concluded that Agaricus bisporus and Pleurotus ostreatus show the highest AOA, while Hypholoma fasciculare has the highest phenolic content. The phenolic content did not show any correlation with AOA, leading us to conclude that there are other antioxidant compounds present in the extracts.

Our study illustrates the histomorphological features of the intestine of frogs living in different surrounding areas of the Hrazdan River characterized by different degrees of pollution. The intestinal epithelium of frogs living near the most polluted parts of the river (villages Darbnik and Geghanist) illustrates phenomena of pyknotic changes and necrosis, the presence of a great number of lymphocytes and lymphoid tissue accumulations in the epithelium. An increasing amount of fibroblasts is observed in the mucous membrane. Our study indicates the increased activation process of the mast cells and the presence of their accumulations in submucosal layers of the intestines of frogs living in the most polluted parts of the river.

Self-association process of mitoxantrone molecules in water-saline solution depending on concentration, temperature and solution ionic strength has been studied. It was shown that in water-saline solutions associates of mitoxantrone molecules are formed and their domination (stacking-like or molecules are bound by hydrogen bonds) strongly depends on not only mitoxantrone concentration, but also temperature and solution ionic strength.

Comparison of values of the binding constant (K) and number of binding sites (n) of methylene blue, ethidium bromide and acridine orange with DNA and RNA has been carried out. It was revealed that values of these parameters do not depend on nucleic acid type. It was shown that in the case of binding of each of these ligands to double-stranded (ds) DNA and ds-RNA the values of K and n are practically similar.

Totally twenty three thermophilic bacilli strains were isolated from Karvachar (70ºC) and Zuar (42ºC) geothermal springs of Nagorno Karabakh. The comparison of generated 16S rDNA sequences of the isolates with the ones available in GenBank database indicates their relations to nine species distributed in four genera: Aeribacillus (A. pallidus), Anoxybacillus (A. flavithermus, A. suryakundensis, A. rupiensis, Anoxybacillus sp.), Bacillus (B. licheniformis, B. simplex, B. cereus) and Geobacillus (G. toebii). Representatives of genus Anoxybacillus was dominated in the Karvachar geothermal spring composing 67% of all detected isolates. Zuar spring was populated by representatives of A. rupiensis and G. toebii.

Hydroecological studies in different parts of the Dzknaget River were carried out in 2015–2017. Based on data of benthic macroinvertebrates spatial and temporal patterns of functioning of different ecotopes through river course have been revealed as well as the differences in sustainability have been discussed. The results of water quality assessment by different bioindication methods have shown that at all seasons water quality in the middlestream part was higher than in the downstream part. Also it’s been proved that the R. Dzknaget has low negative impact on Lake Sevan water quality.

Ecological and agricultural risks of heavy metal pollution of soils in risky areas around Kapan City (RA) were investigated. Soil samples were collected in June 2013 and analyzed for Cr, Mn, Ni, Cu, Zn, As, Mo, Cd, Pb, Co, Hg by the mass spectrometric method. The investigations showed that the soils around Kapan copper-molybdenum combine and Geghanush tailing dump were significantly polluted with heavy metals, which may have posed serious risks not only to soil biological health, but also to agricultural production.

During investigations carried out in “Yerevanyan Lich” reservoir from 2015 to 2016 waterbloom with different groups of algae was registered. The change of dominant groups from dominance by diatoms to cyanobacteria was observed in the phytoplankton community of reservoir during the study period. High quantitative values of diatomic algae were the result of quantitative growth of Melosira varians, Fragilaria crotonensis and Stephanodiscus hantzschii species. High quantitative values of blue-green algae were the result of quantitative qrowth of Anabaena cylindrica and Oscillatoria limnetica species. The values of saprobic index in the reservoir in the study period fluctuated from 1.5 to 1.99. The saprobity in the reservoir was changed from α-oligosaprob to β-mezosaprob level. The highest value of the Shannon biodiversity index was recorded in May of 2015, and the lowest in September of 2016, which shows that there was quantitatively monodominancy of blue-green algae Oscilatoria limnetica, which is pressing diversity of algae in the reservoir.

The analyses of conformational diversity of Aβ(1-42) peptide aggregates by transmission electron microscope (TEM) visualization evidenced the simultaneous presence of non mature small protofibrils, mature fibrils and ribbon-like structural forms. In the presence of extract and phenol glycosides from rose petals, the deformations of aggregates and the amorphous bundles without clear structure were registered. The observations are in line with the ability of plant preparations to hinder the aggregation of Aβ(1-42) and to disaggregate the preformed aggregates. The work manifested that TEM is a reasonable approach in seeking effective agents for treatment of amyloid diseases and evaluating plant medicines as such agents.

Evaluation of the role of genetic factors in the inheritance and the explanation of the inheritance patterns of above mentioned abilities become important connected with learning objectives. This paper refers the patterns of inheritance of motor and spatial visualization abilities. Test systems for the assessment of spatial visualization and motor abilities were studied by us attempting to figure out the patterns of inheritance of above mentioned abilities by implementation of spatial visualization and motor ability tests.

In the article researches on increase of hydrophobic properties of protective clothes are given. This makes it possible to spend, if necessary, a longer time on the territory infected with toxic substances while remaining safe. The results of the research are protected by the corresponding RA patent.