Vol. 38 No. 1 (203) (2004)

The perchlorate and nitrate anions, and also ion pairs Li⁺ClO$^–_4$ and Li⁺NO$^–_3$ have been studied by ab initio quantum chemical methods. Calculation of geometry and vibrational frequencies for the free anions and for monodentate, bidentate and tridentate structures of ion pairs has been performed at the RHF/6-31+G(d) and B3LYP/6-31+G(d) levels.

The influence of saturated with tetraphenylhydrazine (TPhH) micelles on the rate of diphenylamine reaction with potassium persulfate has been studied. It is shown that the rate of accumulation of a reaction product in presence of preliminary saturated with TPhH micelles decreases less in comparison with non- treated with TPhH micelles. Obtained results confirm our early assumption that located in a hydrophobic nucleus of micelles TPhH is spatially separated with persulfate, and the process of diphenylamine oxidation stops on stage 1.

Complexation of Re(VII), Mo(VI), V(V) and W(VI) ions on «Fixion-50» cationite fixed layers has been studied using oxalic, tartaric and citric acids solutions as mobile phases. The row of relative stability of complexes of indicated ions with appropriate acids has been revealed. The obtained date of using the two versions of ion-exchange chromatography (column and thin-layer) do not differ, and it confirms their reliability and accuracy. It is expedient to apply the ion-exchange thin-layer chromatography method more widely for the study of complexation in solutions, because this version of chromatography is more express and does not suppose the use of complicated and expensive instruments.

An interaction of perrhenat-ions with Methyl Violet and Crystal Violet triphenylmethanic basic dyes has been studied by amperometric titration method. Titration has been carried out by dyes oxidation current on the platinum indicating electrode at +1.4 V potential. It has been estimated that equivalent point of the chemical reaction is observed at 1 : 1 molar ratio of the reacting components. Acidity optimal for the determination of rhenium(VII) corresponds to the 0.1–1.0 mol/L and 0.1–1.5 mol/L phosphoric acid solutions, correspondingly for Methyl Violet and Crystal Violet. Submission to the amperometry’s main law observed within 2·10^-4–4·10^-3 mol/L rhenium(VII) concentration range. It is also studied the influence of the series of accompanying elements on the amperometric determination of rhenium(VII). Mathematical treatment of experimental data obtained has been done.

New derivatives of unsaturated γ-lactones containing tetrazole ring have been synthesized by the interaction of substituted cyanobutenolids with inorganic azids.

Isolation and fractionation of total methanol extract, obtained from Hypericum perforatum L. flowers, using the method of gel-chromatography on columns, containing sephadex LH-20, were performed. Absorption and fluorescent spectroscopy, as well as the method of TLC have shown the high purity of obtained hypericin preparations. Interaction between hypericin and DNA was investigated. It was shown that hypericin interacts with purine and pyrimidine sequences of DNA selectively and in different ways.

Aftereffects of high temperature on the kinetics of slow induction of chlorophyll a fluorescence were studied in Chlorella. Heating of alga at the temperature over 45°C caused decrease of induction curve parameters P and M. Changes of these parameters indicated a suppression of photosystem 2 activity. Photosystem 1 was more stable to the high temperature effect. The results suggest that an algae thermosensitivity may be evaluated by changes in the induction curves of slow fluorescence in the preheated objects. The pattern of changes in kinetic curves may indicate disturbances in particular sites of photosynthetic electron transport chain.

Curves of Etidium Bromide binding with single and double stranded polynucleotide poly[d(A-T)]-poly[d(A-T)] were obtained in Scatchard coordinates. It was revealed that EtBr binds to double stranded poly[d(A-T)]-poly[d(A-T)] in two ways. Furthermore, EtBr may form two type complexes with one stranded poly[d(A-T)]. Values of K – binding constant and n – number site size for these complexes were obtained. Parameters of EtBr binding with single stranded and double stranded polynucleotide poly[d(A-T)J coincide with those for EtBr–B–DNA complexes.

L-lysine production is based on the use of Corynebacterium glutamicum strains. With the cloning of the genes involved in lysine biosynthesis it is possible to investigate the influence of particular gene or group of genes on the yield of lysine. PEP carboxylase coding ppc gene and dihydrodipicolinate synthase coding dapA gene are the key genes in lysine biosynthesis. In the present work the plasmid pPPC:DAP has been constructed, containing ppc and dapA genes of Brevibacterium lactofermentum and the effect of this plasmid on lysine production increase with strain B. lactofermentum has been shown.

The changes of statistical characteristics of heart rhythm during carrying out of maze-model tasks on the computer are investigated. Two groups of probationers were allotted by their reaction to the loading: the first group is characterized by the decreasing of strain index (SI); the second group – by the increasing of SI. It is shown, that at the most of probationers, carrying out the tasks with high efficiency, the heart rhythm regulation is realized by the level of autonomous contour, while at the most of probationers carrying out the tasks with low efficiency – by the level of central contour.

Twenty four species of agaricoid and gasteroid basidiomycetes from different geographical regions of Armenia are recorded for the first time. The list includes the species, which belong to the division Eumycota, subdivision Basidiomycotina, classes Homobasidiomycetes and Gasteromycetes, 9 families and 18 genera.

Electrochemical behavior of N,N-diphenyl- and N,N'-diphenylthioureas, as well as Te (IV) has been studied in sulphuric and hydrochloric acids media. It has been shown that amperometric titration can be carried out both by the reagents oxidation and Te (IV) restoration current. Optimal conditions for amperometric titration: acidity, concentrations of reagents, range of Te (IV) determined concentrations have been revealed. Mathematical treatment of experimental data has been done. The method has been applied for tellurium determination in the Te containing ore.

We studied cultured peripheral blood (PB) and/or bone marrow (BM) cells of 48 patients with chronic myeloid leukemia from Hematological Center of Armenia. There were 29 women (age 10–82 years) and 19 men (age 20–82 years). On the basis of clinical and hematological data all patients are divided into 2 groups; in the 1-st group 41 patients are involved (in chronic phase), in the 2-nd group – 7 patients (in blast crisis phase). 38 patients (93%) of 41 from the 1-st group have typical chromosome translocation t(9;22) (q34, q11) (Philadelphia chromosome) in bone marrow and/or peripheral blood cells. There was no correlation between obtained results on Ph+ with age and sex in the investigated group. In the 2-nd group together with Ph-chromosome in 7 (17%) patients is indicated extra Ph-chromosome, i(17q), trisomy 8, trisomy 19, marker.

It has been shown that after the recovery of nitrogene nutrition of starved yeasts the amount of water soluble proteins sinthesied by endogene nitrogene source is 2 times higher than the amount of proteins sinthesied by exogene nitrogene source.

In vegetative experiments the influence of salts of heavy metals and organic fertilizer on crop of green weight of com and spring crop barley in conditions of forest brown soils is investigated. It is established that of heavy metals the manganese positively influences the crop of green weight of above mentioned culture and copper and lead influence negatively.