2. Articole
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Item ASSESSMENT OF KINETIC PARAMETERS IN THE WATERS OF THE NISTRU COURSE IN THE SECTION NASLAVCEA – DUBASARI(2006) Bunduchi, Elena; Duca, Gheorghe; Gladchi, Viorica; Goreaceva, Nelli; Mardari, IgorThe current work represents the results of a monitoring executed on Nistru River waters between October 2003 and September 2005. The water quality was evaluated on the basis of such kinetic indicators as redox state and capacity of inhibition. The obtained results shows that Nistru River water in the segment Naslavcea village – Dubasari barrage are continuously polluted with reducing substances that diminish the H2O2 content, that actually determines the redox state of natural waters and the content of free radicalsItem THE STUDY OF REDOX CONDITIONS IN THE DNIESTER RIVER(2008) Gladchi, Viorica; Goreaceva, Nelli; Duca, Gheorghe; Bunduchi, Elena; Romanciuc, Lidia; Mardari, Igor; Borodaev, RuslanThe work presented in the paper discusses the contribution of the Novodnestrovsc water system to the formation of redox conditions in the lower Dniester. The conclusions were drawn on the basis of a long-term protocol of analyses that included the analysis of the oxygen regime, evaluation of the content of hydrogen peroxide,rH2, biological oxygen demand as well as other additional parameters.Item ESTIMATION OF THE NATURAL WATER SELF-PURIFICATION CAPACITY FROM THE KINETIC STANDPOINT(2008) Duca, Gheorghe; Bunduchi, Elena; Gladchi, Viorica; Romanciuc, Lidia; Goreaceva, NelliThe current paper contains a synthesis of the processes of chemical auto-purification that take place in natural waters; examples of mechanisms of such processes occurring with participation of dissolved organic matter, oxidants of the biogeochemical cycle of oxygen and of transition metals including copper and iron are presented. The kinetic indicators of natural water quality are presented as well.Item CU(II) COMPLEXES WITH 4-ALLYLTHIOSEMICARBAZONE AS POSSIBLE ANTIOXIDANT AGENTS(2022) Ulchina, Ianina; Celac, Marina; Graur, Vasilii; Tsapkov, Victor; Garbuz, Olga; Gulea, AurelianOxidation is an essential part of aerobic metabolism in living organisms. In this process, free radicals are constantly generated. It is widely known that free radicals play a dual role in vivo as both beneficial and adverse compounds. In order to maintain the balance of the activity of the free radicals in living cells, the organism has evolved antioxidant defense systems, protecting against free radical damage. However, when our endogenous defense system has incomplete efficiency, or a rise in free radicals under special conditions like smoking, chemical air pollutants, radiation, and inflammation, the imbalance between free radicals and antioxidants results in oxidative stress, which is now believed to be one of the important factors in the occurrence of certain human diseases including atherosclerosis, rheumatoid arthritis, cancer, and neurodegenerative diseases. So, the search of possible antioxidants agents is of interest, because they protect the body against damage by harmful free radicals. For this purpose two copper(II) coordination compounds of 1-(morpholin-4-yl) propane-1,2-dione 4- allylthiosemicarbazone (HL) with 1,10-phenantroline (1,10-Phen) and 2,2’-bipyridyl (2,2’- Bpy) were synthesized. On the first stage of the experiment the ethanolic solution of Cu(NO3)2⸱3H2O reacts with 4-allylthiosemicarbazone HL and on the second stage the ethanolic solution of the prepared precursor Cu(L)NO3 reacts with bidentate amines forming crystalline coordination compounds. The composition of these compounds was determined using elemental analysis for copper: Cu(1,10-Phen)(L)NO3, Cu(2,2’-Bpy)(L)NO3. The molar conductivity values of the synthesized coordination compounds are in the range 82-98 Ω- 1∙cm2∙mol-1 that indicates that these complexes are 1:1 electrolytes. A standard ABTS•+ method has been used to determine the antioxidant properties of synthesized compounds and trolox was used as a reference. The pro-ligand HL is less active than trolox, its coordination to copper(II) atom decreases antioxidant activity. The introduction of bidentate amines into the internal sphere of precursor increases the activity of complexes, that become 4 times more active than pro-ligand HL, 6 times more active than precursor, and also more active thanItem STUDY OF THE ANTIOXIDANT PROPERTIES OF SOME METHYLPHENYLTHIOSEMICARBAZONES(CEP USM, 2022-09-29) Erhan, Tatiana; Gulea, Aurelian; Garbuz, OlgaItem THE STUDY OF REDOX CONDITIONS IN THE DNIESTER RIVER(Academia de Știinițe a Moldovei, 2008) Gladchi, Viorica; Goreaceva, Nelli; Duca, Gheorghe; Bunduchi, Elena; Romanciuc, Lidia; Mardari, Igor; Borodaev, RuslanThe work presented in the paper discusses the contribution of the Novodnestrovsc water system to the formation of redox conditions in the lower Dniester. The conclusions were drawn on the basis of a long-term protocol of analyses that included the analysis of the oxygen regime, evaluation of the content of hydrogen peroxide, rH2, biological oxygen demand as well as other additional parameters.Item ESTIMATION OF THE NATURAL WATER SELF-PURIFICATION CAPACITY FROM THE KINETIC STANDPOINT(Academia de Știinițe a Moldovei, 2008) Duca, Gheorghe; Bunduchi, Elena; Gladchi, Viorica; Romanciuc, Lidia; Goreaceva, NelliThe current paper contains a synthesis of the processes of chemical auto-purification that take place in natural waters; examples of mechanisms of such processes occurring with participation of dissolved organic matter, oxidants of the biogeochemical cycle of oxygen and of transition metals including copper and iron are presented. The kinetic indicators of natural water quality are presented as well.Item ASSESSMENT OF KINETIC PARAME TERS IN THE WATERS OF THE NISTRU COURSE IN THE SECT ION NASLAVCEA – DUBASARI(Academia de Știinițe a Moldovei, 2006) Bunduchi, Elena; Duca, Gheorghe; Gladchi, Viorica; Goreaceva, Nelli; Mardari, IgorThe current work represents the results of a monitoring executed on Nistru River waters between October 2003 and September 2005. The water quality was valuated on the basis of such kinetic indicators as redox state and capacity of inhibition. The obtained results shows that Nistru River water in the segment Naslavcea village – Dubasari barrage are continuously polluted with reducing substances that diminish the H2O2 content, that actually determines the redox state of natural waters and the content of free radicals