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  • Author: Mária Szabó x
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Quantitative Assessment of Landscape Load Caused by Mining Activity

Abstract

In Hungary, not only the aftermath of the extraction in the past nearly 150 years, but also the economic changes taking place in the past two decades have had significant environmental consequences manifested, above all, in the landscape. It is, however, not sufficient to investigate the landscape components separately; it is necessary to explore connections within the landscape. Accordingly, the chief aim of this presentation has been, on the one hand, to work out the method of landscape load index, based on a quantitative database of mining claims and deposits of mining waste, which has revealed their impacts on the landscape as well. On the other hand, we have also aimed at developing the method of the mining load index of certain geographical landscape units. By calculating and analysing the indices, we have intended to build a quantitative database suitable for investigating the impacts of mining activities on the landscape. On the basis of the indices, the impacts and consequences could be ranked, and it was also possible to compare the impacts of different mining claims and waste deposits in three different landscape categories. With the main result of our examination, this will make it possible to investigate concrete problems and landscape conflicts caused by the landscape use of mining or its aftermath in different landscape units with a high load index.

Open access
Antibacterial activity of selected snake venoms on pathogenic bacterial strains

Abstract

Snake venoms are aqueous solutions containing peptides and proteins with various biochemical, physiological, and pathophysiological effects. Several snake venom components are used as lead molecules in the development of new active substances for the treatment of cardiovascular diseases, clotting disorders, cancer or pain.

Antibacterial activity has also been attributed to snake venoms and proteins isolated from snake venoms. This study provides information regarding the antibacterial activity of venoms obtained from various snake species from the Elapidae and Viperidae families. Minimum inhibitory and bactericidal concentrations of snake venoms were determined for three Gram-positive (Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 29213, and Methicillin-resistant Staphylococcus aureus ATCC 43300) and three Gram-negative (Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, and Pseudomonas aeruginosa ATCC 27853) pathogenic bacteria. The observed effects were correlated with the protein content of each venom, determined using SDS-PAGE analysis and comparison with data available in the literature. Our findings represent a starting point for the selection of snake venoms containing components with potential use as lead molecules in the development of new antibacterial agents, targeting multidrug resistant bacterial strains.

Open access
Preparation and investigation of mefenamic acid – polyethylene glycol – sucrose ester solid dispersions

Abstract

Mefenamic acid (MA) is a widely used non-steroidal antiinflammatory (NSAID) drug. The adverse effects typical of NSAIDs are also present in the case of MA, partly due to its low water solubility. The aim of this study was to increase the water solubility of MA in order to influence its absorption and bioavailability. Solid dispersions of MA were prepared by the melting method using polyethylene glycol 6000 and different types (laurate, D-1216; palmitate, P-1670; stearate, S-1670) and amounts of sucrose esters as carriers. The X-ray diffraction results show that MA crystals were not present in the products. Dissolution tests carried out in artificial intestinal juice showed that the product containing 10 % D-1216 increased water solubility about 3 times. The apparent permeability coefficient of MA across human Caco-2 intestinal epithelial cell layers was high and, despite the difference in solubility, there was no further increase in drug penetration in the presence of the applied additives.

Open access
Trophic Status and Phytoplankton Limitation Conditions in a Few Bulgarian and Hungarian Danube River Wetlands

Abstract

The phytoplankton limitation conditions in a few Bulgarian and Hungarian wetlands and in two more sampling sites, one for each Danube stretch, were investigated by means of trophic state index of Carlson (1977) for phytoplankton chlorophyll-a (CHL), Secchi disk depths (SD), total phosphorus (TP), and total nitrogen (TN) concentrations. Phytoplankton of both river sites was not limited by non-algal turbidity, nor was they phosphorus and nitrogen limited. In summer months the studied wetlands were predominantly nitrogen limited, while in spring and autumn limitation by non-algal turbidity prevailed.

Open access
Bacterioplankton from Two Hungarian Danube River Wetlands (Beda-Karapancsa, Danube-Drava National Park) and its Relations to Environmental Variables

Abstract

Seasonal and spatial distribution of bacterioplankton from two Hungarian oxbow lake type wetlands, Mocskos-Danube and Riha, was studied. They were both covered by macrophytes and they had different hydrological connectivity to the Danube. The six sampling campaigns from April to October 2014 included parallel samples from the Danube River at Mohács, Hungary. Bacterial abundance was the highest in spring and in Mocskos-Danube, followed by Mohács and Riha. Positive relationships existed between bacterioplankton and temperature on one hand and suspended solids, pH, PO4-P and chl-a on the other. Negative correlations were with DOC, dissolved oxygen and NH4-N.

Open access