Vol. 53 No. 1 (248) (2019)

Densities and electrical conductivities for copper(II) chloride solutions in DMSO and water–DMSO equimolar mixture have been measured at different temperatures. Apparent molar volumes, partial molar volumes and transfer molar volumes of the solvated copper(II) cations were derived and interpreted in terms of ion-solvent interactions. The ligand-field and temperature effects on the partial molar volumes and electrical conductivities were discussed as well.

The esterification reaction of erythritol, 1,2,3-butanetriol and 1,2,4-butanetriol with carboxylic acids of sunflower, olive and corn oils has been used to synthesize non-glyceride analogues of the corresponding edible oils. Effective methods for the preparation of tetraacyl erythritol, triacyl erythritol and triacyl butanetrioles have been developed. The physicochemical properties of the obtained compounds are defined.

In the work the joint effect of millimeter range electromagnetic waves and heavy metal cadmium ions on the intensity of lipid peroxide oxidation and catalase activity in wheat seedling cells has been studied. The obtained data were compared with the results received at separate influence of each of these factors. It was shown that the joint effect of electromagnetic waves and heavy metal results in improving of criteria of free-radical processes and antioxidant system activation. It was also shown that acting separately the aforementioned factors lead to sharp changes of these criteria.

The antimicrobial activity of essential oils (EO) from several plants of Lamiaceae family (Ziziphora clinopodioides Lam., Thymus vulgaris L., Ocimum × citriodorum, O. basilicum var. purpureum, O. basilicum var. thyrsiflora, Origanum vulgare L.), spread in Armenia, was studied using agar diffusion method. As test-organisms the ampicillin-resistant Escherichia coli dp5α-pUC18 and non-resistant E. coli VKPM M-17 were used. Dimethyl sulfoxide was used as the solvent and negative control; gentamicin was applied as the positive control. O. × citriodorum, O. basilicum var. purpureum and T. vulgaris EO expressed the strongest activity against E. coli dpα-pUC18; minimal inhibitory concentrations (MIC) was 6.25 μL·mL^–1. MIC of the O. basilicum var. thyrsiflora EO was 12.5 μL·mL^–1. Z. clinopodioides and O. vulgare EO MIC was 50 μL·mL^–1. Thus, EO from the Lamiaceae family plants could be recommended as antimicrobial agents against antibiotic-resistant bacteria.

As a result of studies macromycetes of Shikahogh State Reserve 436 species of macroscopic fungi are now recorded in the study area. Of all macromycetes found, to the best of our knowledge, 12 species and 2 genera are recorded in Armenia for the first time.

e present study was conducted in Mazandaran Province of Northern Iran. A total of 76 species and 2 variations of macrofungi belonging to phyla Basidiomycota and Ascomycota have been collected and identified. Among described species, 54 are edible, 24 possess only medicinal properties, 15 are reported for the first time for Mazandaran Province and 3 Russula species – for mycobiota of Iran. From them 42 species grow on northern slopes, 12 – on southern slopes, and 29 – on all facing slopes. They belong to xylotrophs (37), coprotrophs/xylotrophs (3), humus/litter saprotrophs (17) and mycorrhizal (20) species.

n the article changes in evoked potentials (EP) resulting from the execution of creative verbal tasks have been studied. Analysis of amplitude characteristics of evoked potentials caused by light stimuli revealed a significant increase in the amplitude of N200 component in frontal and prefrontal areas of the left hemisphere. An increase in the amplitude of N200 component in the temporo-parieto-occipital areas of the right hemisphere was also revealed. The obtained data lead us to the assumption that implementation of creative tasks with expressed elements of complexity is accompanied with significant activity of the frontal and temporoparieto- occipital areas of the cerebral cortex.

A modern study of the Arpa River and its tributaries allows evaluating the ecological state of the ecosystem according to phytoplankton development indicators and comparing it with previous data. It is known that modified control of hydrosystems for hydropower stations changes quantitative and qualitative indicators of water, which increases anthropogenic impact on the diversity of hydrobionts. In order to mitigate the environmental risks and improve the ecosystem self-cleaning it is necessary to carry out continuous monitoring and rapid assessment of the change in the composition of microalgae indicators.

Comparative study of yeast growth and morphology of cells in nitrogen containing medium and under nitrogen starvation conditions has not been done before. The aim of this study was to investigate the ultrastructural changes in yeasts C. guilliermondii NP-4 cultivated with and without nitrogen. The yeast biomass cultivated under nitrogen starvation conditions has been twice lower, than in case of growth in nitrogen containing medium. Ultrastructural analysis of cells, carried out with scanning electron microscope, showed morphological changes in cells. A negative correlation of biomass and cell size was observed.

Plantago major L. is a popular medicinal herb, which has been being used for treatment of various diseases in traditional health systems. The aim of present study was to examine the antibacterial and anti-phage activity of P. major ethanol extract. P. major fresh raw material extract was possessed of moderate antibacterial activity against Escherichia coli VKPM-M17, Salmonella typhimurium TA 100 and Staphilococcus aureus MDC 5233 bacterial strains. Anti-phage activity was evaluated by double overlay plaque assay against T4 phage of E. coli C-T4. Fresh, dried and frozen raw materials showed moderate antiviral activity: 1 mg/mL concentration of fresh row material ethanol extract caused 0.927Log₁₀ reduction of phage units, while the frozen and dried plant ethanol extracts caused 0.875 Log₁₀ and 0.821 Log₁₀ reductions, respectively. Fresh raw material contains the highest concentration of vitamin C.