Studia Universitatis Moldaviae. Stiinte reale si ale naturii

14-19

Authors: Denis BULAT, Victor CIORNEA, Dumitru BULAT

In the present paper are reflected the peculiarities of ichtyofauna of the river Bâc in 2018. Compared to the results of the research conducted in 2004-2009 there was a substantial worsening the status of ihtiocenosis as a result of massive diversification of pollutants downstream the Călăraşi and Chişinău municipality treatment plants.

25-34

Authors: Alexandru DASCALIUC, Petru CUZA

The summary activity of oxidases, catalases and antioxidant substances in extracts from buds taken for analysis in autumn, winter and spring from pedunculate oak (Quercus robur), sessile oak (Q. petraea) and pubescent oak (Q. pubescens) trees, which grow in the immediate vicinity of the Zloti forest, as well as of the buds of pubescent oak of the trees from other Floristries in the South of Republic Moldova was determined. In winter, the antioxidant activity in the apical and lateral buds of the pubescent oak and of the sessile oak trees noted that the metabolic processes in the buds of the mentioned species are displaced from the biodynamic equilibrium compared to those carried out in the pedunculate oak buds. This proves that pubescent and sessile oak are less resistant to winter conditions compared to pedunculate oak, which is a species better adapted to frost. In spring, in extracts from the buds of pubescent oak there is a tendency to increase the overall oxygen utilization capacity due to the high reductive potential of phenolic substances and oxidases activity along the north-south positive temperatures gradient, in line with the territorial location of the Floristries. An opposite trend was evident in the overall oxygen elimination activity due to catalases activity, which increases earlier in extracts from buds of trees located in the southern part of the country. It turns out that the processes of eliminating the pubescent oak buds dormancy during transition from the winter to spring season are associated with the consecutive increase in the catalases and only after that the activity of the oxidases and of the antioxidant substances from the buds are manifested.

39-44

Authors: Lazăr CHIRICĂ

Due to its location within the sea-shore area of the Black Sea, the Kuialnic Estuary has a genesis almost similar to all the seaside estuaries. Thus, it has undergone through the following phases: of a river, deep valley, bay, lagoon and of an estuary. All of the above-mentioned phases occurred within the post-glacial period and were influenced by the regressive-transgressive character of the Black Sea. The Kuialnic Estuary has definitively separated from the Black Sea by the end of 17th century, through the creation of a coastline.

51-58

Authors: Mihai MÂRZA, Gheorghe NOVAC, Iulian MAMAI, Natalia BURACINSCHI, Dorina BULICANU, Eliza MÎRZA

The analysis of the bibliographic materials and those collected in the field indicate that on the rocks around the Buteşti-Cubani localities, there are 23 species of archegonious plants and 384 species of antofit plants, and on the Stânca-Ştefăneşti: there are 417 species of antofit plants and 17 species of archegonious plants. The anthropic action on the vegetal surface of the Prut river rocks becomes more evident for the last century. 311 species are common for both territories. That is why we recommend the creation of a national park, with the inclusion of the already protected areas with the annexation of the new areas, which will ensure the preservation of these unique territories in Europe.

65-69

Authors: О.И. ЦУРКАН, С.И. БУРЫКИНА, Я.М. БИЛАНЧИН, А.В. ПЯТКОВА

The changes under the influence of irrigation and fertilization systems of the fractional potassium composition of the soils in the Southern Ukraine, Chernozem ordinary and Chernozem southern are considered. The amount of groups of potentially available potassium in the layer 0-30 cm are growing up under the influence of irrigation on 40,3% and 57,5% compared with bogarne conditions in the Chernozem ordinary. The rate of fertilizer (manure 200 t/ha + N200P200K60) is made under the basic treatment of the first rotation crop in the aftereffect for 11th year provides a positive balance of exchange potassium in the Chernozem ordinary even if the original content is reduced by 2,1 times more.

77-88

Authors: Vladilena GÎRBU

Selective functionalization of complex scaffolds is a promising approach to increase the pharmacological profiles of natural products and their derivatives. Various C-H functionalizations of the natural compounds: azidation, halogenation, trifluoromethylation and electrochemical oxidation - will be discussed in this review.

97-104

Authors: Maria SANDU, Anatol TĂRÎŢĂ, Raisa LOZAN, Viorica GLADCHI*, Gheorghe DUCA*, Elena MOŞANU, Sergiu ŢURCAN

Assessing the springs and pumps water quality (in the Nistru basin) it was found that in most of the districts there are sources of unpolluted water (8-58%), poorly polluted (10-56%) and moderately polluted (4-42%) waters with nitrates. Springs with significantly polluted water were found in Causeni district (33%) and with very significant pollution were identified in Ialoveni districts (26%), Anenii Noi (20%), Criuleni (15%), Rezina (14%) and Soldanesti (12%) districts, demonstrating the impact of the landfills on the accumulation of nitrates in the groundwater.