Vol. 55 No. 1 (254) (2021)

By the example of heterogeneous catalytic oxidation of propane the process of peroxide radicals transfer from the surface of catalysts into the reactor volume is studied. For comparison ZnO/SiO₂ contacts obtained by depositing the active phase on the silica surface by sol-gel and chemical transport reaction (CTR) were used. It was established that for the case both the temperature of the radicals transfer from the surface to the volume and the value of the activation energy are lower than in the case. It was shown that the modification of the silica gel surface with zinc oxide by the CTR method is more effective as compared with the sol-gel method. It is established that in both cases the active phase of the catalyst exhibits paramagnetic properties. On the basis of the given, semi-artificial kinetic method of radical detachment, the obligatory mechanism of activation failed.

By the interaction between N-methylolthiourea and Co²⁺, Mn²⁺ acetates are obtained compounds that were later used for the synthesis of vinyl bifunctional groups containing polymerizable chelate complexes. These compounds are recommended to be used as crosslinkers for obtaining, on the basis of water-based soluble monomers, spatially cross-linked water-swellable copolymers with applied purpose. There are dynamics of water absorption of copolymers from the time of their stay in water.

The amount of tannins in the leaves of stinging nettle was determined depending on the phenological phase (budding phase, mass flowering phase and fruiting phase). UV spectrophotometric and high performance liquid chromatographic (HPLC) methods were used to quantify tannins in the plant. It was found that the maximum accumulation of this group of substances in nettle leaves occurs in the fruiting phase. Based on the results of the study, the chromatographic method is optimal for the analysis of tannins in nettle leaves.

Vibration pathology is in the second place among diseases connected to the profession. The vibration effect both on the protein fraction shifts and on the activities of I type arginase (Arg) IA and IB from white rat liver has been studied in the conditions of 5-, 10- and 15-day vibration state. In the initial state of vibration some decrease of Arg IA and Arg IB activities was revealed as compared to the control without general protein spectrum change of liver extract. Along with vibration effect, the expression level of Arg IA was increased with duration enhancement, which possibly is due to hyperammonemia, in the result of which ureagenesis is stimulated. Stimulation of easy available adaptation reserves were described due to protein catabolism. Analysis of shifts of general and enzyme protein fractions in the conditions of vibration effect allows to reveal their qualitative and quantitative changes and to make important the organism adaptation reactions that result from anabolic and catabolic process relations. It is possible that the revealed changes in the activity of arginase IA and IB are a biologically expedient mechanism for regulating the activity of hepatic arginase during vibration stress.

Adverse effect of oxidative stress is a huge problem in medicine. In several circumstances, exogenous antioxidants are needed to regulate the amount of reactive species in the body. Plants are considered as a promising source for new antioxidant compounds. The goal of this study was to evaluate the antioxidant potential of extracts of the following herbs: Agrimonia eupatoria, Hypericum alpestre, Rumex obtusifolius and Sanguisorba officinalis using different chemical-based tests. GC-MS technique was used for identification of plant’s volatile bio-active constituents. The results revealed good potential of the tested herbs as sources for new antioxidant compounds.

The study of complexes of groove binding ligand Hoechst 33258 (H33258) with Calf Thymus DNA has been carried out. The data obtained revealed that the melting curves of the complexes of H33258 with DNA are monophasic at low ligand concentrations (0 < r ≤ 0.2) and become biphasic at relatively high concentrations (0.2 < r ≤ 0.33). This effect was revealed to depend on the ionic strength of the solution, and can also occur at high concentrations of the ligand. Comparison of the obtained data with the results for poly(rA)-poly(rU) and poly(dA)-poly(dT) shows a coincidence in the case of DNA and poly(rA)-poly(rU), while in the case of poly(dA)-poly(dT) the melting curves become biphasic at low ligand concentrations and actually do not depend on the ionic strength of the solution.

The article reports the results of microscopic studies of the oregano leaf in the pre-blossom period. In particular, the following anatomical and morphological features of the oregano leaf during the pre-blossom period were revealed: sinuous cuticle, multicellular simple trichomes, capitate trichomes, stomata, essential oil glands. The latter were located only in the central part, and were absent at the margins. The essential oil glands were of high density mostly in the central part of the raw materials preparation, which were harvested from the regions of dry climatic conditions as opposed to the raw materials harvested from the region of wet climatic conditions. The results of the investigation were definitely conditioned by the climatic features of the regions.

The article presents two species of the genus Amauromyza (Diptera, Agromyzidae): A. leonuri (Spencer, 1971) and A. flavifrons (Meigen, 1830), which are widespread in Artsakh Republic. Their biological, ecological and morphological features, prevalence and intensity of infestation, as well as the types of mines are described.

A total of 182 non-typhoid Salmonella enterica (NTS) isolates recovered from patients between 1996 and 2014 were included in the current study focused on class 1 integron detection and its association with multidrug resistance (MDR) phenotype. A high prevalence of isolates displaying MDR and penta-resistance (resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, tetracycline) phenotypes of clinical significance was revealed. Serotype-specific prevalence of antimicrobial resistance as well as class 1 integrons and inserted variable segments was detected in isolates. The results indicated the limitations of current antimicrobial therapy to control infections caused by MDR isolates of NTS, especially belonging to serotype Typhimurium.

This research is focused on the investigation of specific growth rate changes of E. coli  wild type and mutant strains with defect of Hyd, FDH enzymes and FhlA regulatory protein in the presence of N,N'-dicyclohexylcarbodiimide (DCCD) and external formate various concentration during co-fermentation of glucose, glycerol and formate at pHs 5.5-7.5. The highest value of SGR was observed at pH 7.5. It was revealed that SGR depends on external formate concentration at all pHs. DCCD inhibitory effect was shown mainly at pH 7.5 and partially at pH 6.5 and 5.5. In the case of the F₀F₁-ATPase inhibition, FhlA compensatory effect on SGR was revealed.

Patient’s quality of life (QL) measures are endowed with independent predictive value and these factors are considered to be more distinct than patient’s general somatic condition for predicting patient’s health condition. However, the number of researches devoted to QL prediction in the field of medical science is low. The aim of research is evaluation of predictive measure of QL of early aged children. Prospective observational study was carried out. The objects of the research were 2362 early age children (3months-3years old) from pediatric polyclinics of Yerevan. QL of children was evaluated with the international questionnaire “QUALIN”. Wald’s analytical method has been applied for predictive evaluation of QL criteria and formation of risk group. For the analysis and evaluation of the statistical material used SPSS Statistics software package. In social-hygienic factors more important were: family type, conflicts in family, disabled child and frequent morbidity families, presence of artificial nutrition since birthday. Among medico-biological factors the presence of two or more diseases in neonatal period, low and high levels of physical development, weight deficit and obesity, child’s health group and respiratory, nervous and digestive system diseases were more significant. In terms of predictive evaluation of QL, it can be stated that a number of medico-biological and socio-hygienic factors affect the overall formation of QL. By means of predictive evaluation of QL one can originally set apart targeted risk groups and if the score of predictive evaluation is +13 and higher, implement health measures, which may provide with improvements of QL criteria.

Morphofunctional changes in the lungs of rats under the influence of aflatoxin B1 were studied. The data obtained indicate that aflatoxicosis causes marked regressive changes due to pulmonary insufficiency, which are accompanied by massive destruction of lung cells, the presence of altered fields of view of emphysema, diffuse inflammatory foci, as well as an increase in the number of mast cells.

The developmental and behavioral disabilities remain high in children and in adults who were born preterm. In this case assessment of quality of life and development of preterm infants can be very informative and interesting. This is a prospective longitudinal (at 3, 6, 9 and 12 months) study of preterm birth and term control infants selected from pediatric polyclinics of Yerevan. The quality of life (QL) measures were done with QUALIN questionnaire and the developmental measures with Battelle Developmental Inventory. A total of 71 preterm and 105 term control infants underwent study. Among 71 preterm birth infants, who selected on the study at 3 months, 40 infant's score on the BDI was <–1 SD and 1 infants' score on the BDI was <–2 SD. However, at the age of 12 months 32 of these same children showed a BDI score >85. Parents and pediatricians reported worse QL for of preterm infants compared with control group. At same time parents of preterm infants reported better QL for their children compared with pediatricians. The lowest QL and developmental scores among preterm children were detected at 3 months. Improvement of QL and developmental score was observed in the next age groups.