Vol. 46 No. 3 (229) (2012)

The formation of porous materials from the link of sulfates groups on the surface of cellulose whiskers by Ca²⁺ and Ba²⁺ cations has been studied. It has been shown that the introduction of this cations in suspension increases the viscosity of the system.

It is shown that in alkaline medium thiamine (TA) results in H₂O₂ decomposition rate decrease, but in acidic medium inhibits H₂O₂ decomposition catalyzed by Fe(II) cations, which occurs mainly by radical-chain mechanism. In our early works it was established that in alkaline medium ap­proximately 16% of H₂O₂ is being decayed with radical formation. So, TA mainly acts in alkaline medium on the rate of H₂O₂ decomposition, which occurs by radical mechanism. TA·HCl also inhibits the cumene initiated auto­oxi­da­tion, which occurs by radical-chain mecha­nism with degenerated bran­ching. During autooxidation R^• and ROO^• free radicals are formed. It is assumed that TA, as well TA·HCl effectively react with free radicals R^• and ROO^•.

The formation of Ni(II)–Leucine (Leu) complex (1:1) is established. It acts as a model homogeneous catalyst on the decay of cumene hydroperoxide (ROOH) in the studied system H₂O–Ni²⁺–Leu–ROOH. ROOH catalytic decay rate law is: W₀ = –d [ROOH]₀/dt=K_cat [Ni²⁺Leu]₀[ROOH]₀=K_eff[ROOH]₀. The temperature dependence of ROOH decay rate effective constant K_eff (K_eff=K_cat[Ni²⁺Leu]₀=const) in the 50–70⁰C temperature range can be expressed by Arrhenius equation (the activation energy is expressed in kJ/mol): K_eff = (1.87 ± 0.02)105 exp[(–46.6 ± 0.20)/RT], min^–1.

Regularity of potassium persulfat+Co²⁺+dimethylaminoethanol reaction has been studied. The rate of the reaction has been determined: W_s=K_eff [Co²⁺]0,4 [P₀–x][A₀–2x], K_eff = 2·10¹² exp^-60/RT l/mol·min. It has been shown that the reaction occurs by two parallel mechanisms: radical and non-radical,  W_s=W_r+W_nr. Possible mechanism of the radical path of the reaction, where Co²⁺–dimethylaminoethanol is catalytic system, is given.

Bromination reaction of 2,2,3,6,6-pentamethyl-1,7-dioxaspiro[4,4]no-nen-3-one-8 with molecular bromine and N-bromsuccinimide has been studied. New derivatives of spirolactones have been synthesized on the base of 3-bromomethyl derivative.

The influence of EMI EHF as well as the joint effect of physical and chemical factors, EMI EHF and C-2 growth stimulator, influences on total peroxidase activity of Amaranth (Amaranthus L.) germs have been investigated. It has been shown that low intensity irradiation of Amaranthus L. seeds by EMI EHF influences on germs’ oxidation processes intensity. The joint effect of stimulator and external physical field results in increasing of influence of external environment factors on biological system.

The dependence of etilendiamintetraacetat (EDTA) effect on the pH medium and temperature for white rat and Rana Ridibunda frog ureotelic arginases was studied. It was shown that arginase of the liver of frogs under the influence of EDTA was inactivated at pH 7.4–9.5 unlike the rat’s arginase, which is inactivated at same conditions accurately at pH 7.4 only. The inhibitory effect of low temperatures in the process of inactivation in both cases was shown also. Significant differences in the process of inactivation in both cases, which is conditioned by interspecific differences of isofunctional proteins were revealed.

Impact of examination stress on psycho-physiological and cardiodynamic indicators of the students of 9–11th grades at school for gifted children of the city of Sari (IRI) was studied. It was determined that pre-examination emotional stress depends on age, gender and physiological characteristics of a person. Increased heart rate was registered for all teenagers, which was most prominent in male participants. This effect lasted after examination period too. Psycho-emotional stress of the examination period also impacted blood pressure with hyper sympathotony domination was registered.

Under conditions of oxygen deficiency the influence of electrical stimulation Bulbus olfactorius on the impulse activity of bulbar respiratory neurons was studied. Under conditions of normoxia both activation and inhibition of impulse activity of bulbar respiratory neurons are observed with predominance activatory action. At the initial stage of oxygen deficiency on the hypoxic activation background the activatory action of Bulbus olfactorius is less expressed than under conditions of normoxia. At the second stage of hypoxia the activatory influence of this nucleus was significant.

During the survey of parents of 276 children enrolled in auxiliary schools of Armenia the increased incidence of birth of children with oligophrenia is shown in case of contact of their mothers or both of the parents with occupational hazards. The correlation of birth of children with oligophrenia in families with father alcohol or drug abuse is detected. The increased frequency of birth of children with oligophrenia is also revealed during long-term use of medications by their parents and in case of their high sickness rate with viral diseases. In the group of parents of children with Down syndrome the role of environmental factors and age of mothers is revealed.

With application of Tradescantia (clon 02) plants test-object was studied the genotoxicity of soil samples’ pollution depending on heavy metals (HM) concentration. At high level of investigating samples pollution by some HM was revealed increase of all studied mutation events frequency in stamen hairs (SH) and the micronuclei in tetrads of microspore (MN) depending on investigating points.

The content of mercury in the main types of fish samples, which are reproduced in RA and in imported frozen ocean fish and in samples of canned fish, was determined. It has been shown that the content of mercury in imported fish samples is higher than in samples, which are reproduced in RA.

It is established that waterbugs play an important role in reducing the number of horseflies in Armenia. The horseflies are particularly vulnerable to attack while watering at the period of their mass flight. Study results allow recommend tо use waterbugs in the organization of biological control against the blood sucking flies.