Biological control against microbial infections has a great potential as an alternative approach instead of fungicidal chemicals, which can cause environmental pollution. The pigment producer Metschnikowia andauensis belongs to the antagonistic yeasts, but details of the mechanism by which it inhibits growth of other microbes are less known. Our results confirmed its antagonistic capacity on other yeast species isolated from fruits or flowers and demonstrated that the antagonistic capacity was well correlated with the size of the red pigmented zone. We have isolated and characterized its red pigment, which proved to be the iron chelating pulcherrimin. Its production was possible even in the presence of 0.05 mg/ml copper sulphate, which is widely used in organic vineyards because of its antimicrobial properties. Production and localisation of the pulcherrimin strongly depended on composition of the media and other culture factors. Glucose, galactose, disaccharides and the presence of pectin or certain amino acids clearly promoted pigment production. Higher temperatures and iron concentration decreased the diameter of red pigmented zones. The effect of pH on pigment production varied depending of whether it was tested in liquid or solid media. In addition, our results suggest that other mechanisms besides the iron depletion of the culture media may contribute to the antagonistic capacity of M. andauensis.

A new indirect method has been developed for the determination of sulphuric acid and sulphur dioxide by flame atomic absorption spectrometry, thereby extending the range of application of AAS to some non-metallic substances. Under certain atomization conditions in air-acetylene flame, the absorbance signal of some alkali earth metal salts, such as magnesium shows significant dependence from the anions present. For instance, Mg(ClO4)(2) produces almost ten times higher absorbance than MgSO4 in the same concentration, and this phenomenon is due to the thermal differences of these alkali earth salts. When sulphuric acid is added to Mg(ClO4)(2) solutions, a continuously decreasing FAAS calibration series is obtained. Using this method unknown sulphuric acid concentration can be determined in samples. The presence of other acids - except phosphoric acid - does not interfere, since they are evaporated during the dry aerosol formation in the flame. The limit of detection for sulphuric acid and sulphur dioxide is 22 mu g/m(3) and 14 mu g/m(3) The limit of detection for the obtained solution is 0.11 mg/L and 0.07 mg/L for sulphuric acid and sulphur dioxide using 50 min sampling time at 1 L/min air suction rate into 10 ml appropriate liquid, respectively (enrichment factor = 5000 with respect to volume). The linear range is 0.5 - 5.0 mg/L. The recovery of spiked samples are 98%. The SO2 and SO32- salts can be similarly determined by this method based on the quantitative absorption of SO2 in H2O2 which yields sulphuric acid. The sulphate content of the solutions was determined by turbidimetric and ion chromatographic methods and the results were in good agreement with the developed method.

The lysis of red blood cells was shown to occur in human ruptured atherosclerotic lesions and intraventricular hemorrhage (IVH) of the brain. Liberated cell-free hemoglobin was found to undergo oxidation in both pathologies. We hypothesize that hemoglobin-derived peptides are generated during hemoglobin oxidation both in complicated atherosclerotic lesions and IVH of the brain, triggering endothelial cell dysfunction. Oxidized hemoglobin and its products were followed with spectrophotometry, LC–MS/MS analysis and detection of the cross-linking of globin chains in complicated atherosclerotic lesions of the human carotid artery and the hemorrhaged cerebrospinal liquid of preterm infants. The vascular pathophysiologic role of oxidized hemoglobin and the resultant peptides was assessed by measuring endothelial integrity, the activation of endothelial cells and the induction of proinflammatory genes. Peptide fragments of hemoglobin (VNVDEVGGEALGRLLVVYPWTQR, LLVVYPWTQR, MFLSFPTTK, VGAHAGEYGAELERMFLSFPTTK, and FLASVSTVLTSKYR) were identified in ruptured atherosclerotic lesions and in IVH of the human brain. Fragments resulting from the oxidation of hemoglobin were accompanied by the accumulation of ferryl hemoglobin. Similar to complicated atherosclerotic lesions of the human carotid artery, a high level of oxidized and cross-linked hemoglobin was observed in the cerebrospinal fluid after IVH. Haptoglobin inhibited hemoglobin fragmentation provoked by peroxide. The resultant peptides failed to bind haptoglobin or albumin. Peptides derived from hemoglobin oxidation and ferryl hemoglobin induced intercellular gap formation, decreased junctional resistance in the endothelium, and enhanced monocyte adhesion to endothelial cells. Enhanced expression of TNF and the activation of NLRP3 and CASP1 followed by the increased generation of IL-1β and nuclear translocation of the NF-κβ transcription factor occurred in response to hemoglobin-derived peptides, and ferryl hemoglobin in endothelium was upregulated in both pathologies. We conclude that the oxidation of hemoglobin in complicated atherosclerotic lesions and intraventricular hemorrhage of the brain generates peptide fragments and ferryl hemoglobin with the potential to trigger endothelial cell dysfunction.

Vascular calcification is a life-threatening clinical condition in chronic kidney disease (CKD) and is associated with reduced zinc serum levels. Anemia is another frequent complication of CKD. Hypoxia-inducible factor (HIF) stabilizers, also known as HIF prolyl hydroxylase inhibitors (PHI), are promising candidates to treat CKD-associated anemia by increasing erythropoietin synthesis. Recent evidence suggests that HIFs play a pivotal role in vascular calcification. Our study explored feasible impacts of HIF PHI on phosphate (Pi)-induced calcification of vascular smooth muscle cells (VSMCs) and tested whether zinc might inhibit this mineralization process. Treatment of VSMCs with PHI aggravated Pi-induced calcium deposition and Pi uptake. PHI promoted Pi-induced loss of smooth muscle cell markers (ACTA-2, MYH11, SM22α) and enhanced osteochondrogenic gene expression (Msx-2, BMP-2, Sp7) triggering osteochondrogenic phenotypic switch of VSMCs. These effects of PHI paralleled with increased pyruvate dehydrogenase kinase 4 (PDK4) expression, decreased Runx2 Ser451 phosphorylation, and reduced cell viability. Zinc inhibited Pi-induced mineralization of VSMCs in a dose-dependent manner and also attenuated the pro-calcification effect of PHI in Pi-induced mineralization. Zinc inhibited osteochondrogenic phenotypic switch of VSMCs reflected by lowering Pi uptake, decreasing the expressions of Msx-2, BMP-2, and Sp7 as well as the loss of smooth muscle cell-specific markers. Zinc preserved phosphorylation state of Runx2 Ser451, decreased PDK4 level, and restored cell viability. PHI alone reduced the expression of smooth muscle markers without inducing mineralization, which was also inhibited by zinc. In addition, we observed a significantly lower serum zinc level in CKD as well as in patients undergoing carotid endarterectomy compared to healthy individuals. Conclusion - PHI promoted the loss of smooth muscle markers and augmented Pi-induced osteochondrogenic phenotypic switch leading to VSMCs calcification. This mineralization process was attenuated by zinc. Enhanced vascular calcification is a potential risk factor during PHI therapy in CKD which necessitates the strict follow up of vascular calcification and zinc supplementation.

A chromium speciation and preconcentration method was developed for graphite furnace atomic absorption spectrometry (GFAAS). This method was based on a continuous liquid-liquid extraction technique. For the separation and enrichment of the chromium species, an ion-pair forming quaternary ammonium compound was used. The sample and chloroform with the ion-pair forming agent were introduced into a patented extraction glass device. After the extraction, the Cr(VI) content of real water samples was determined by GFAAS. The optimized extraction conditions were as follows: the detection limit (S/N = 3) of 0.01 mu g L-1, linear range of 0.04-5.00 mu g L-1 and precision (RSD, n = 3) <= 3.0%. The advantages of this method are its simplicity, cost efficiency, the high enrichment factor of chromium species and easy usage with the GFAAS technique. Thus, the concentration of the chromium species can be determined at sub mu g L-1 level.

Our research group have been contributing to the development of speciation analytical techniques with the elaboration of various chromium speciation methods since 1990. In the past period 20 divers techniques have been developed for the separation, enrichment and determination of toxic chromium (VI) and essential chromium (III) forms in environmental samples. The aim of present work is to compare the analytical performance of introduced chromium speciation techniques, and to get an overall picture about the limit of detection and range of quantification of the on-line and off-line techniques, and to present the optimal experimental arrangements to achieve the best possible analytical performances using the latest analytical tools. The analytical performance of on-line chromium speciation techniques can be improved by the appropriate enrichment of chromium forms, by using interface connecting the separation/enrichment unit and the element selective detector with the highest sample introduction efficiency, and by using a detector with the best possible sensitivity. The lowest limit of detection (3 sigma) for Cr (VI) (20 pg/mL) could be achieved by using C-18 chromatographic separation/enrichment column, hydraulic high pressure nebulizer (HHPN) and acetylene - nitrous oxide flame emission detection unit. The10 pg/mL (3 sigma) limit of detection of off-line chromium speciatron method was reached by 50-fold enrichment using liquid-liquid extraction (LLE) and graphite furnace atomic absorption spectrometry (GFAAS). These techniques are suitable for the chromium speciation analysis of natural samples with various matrices.

Systemic lupus erythematosus (SLE) and Sjögren’s syndrome (SS) are systemic autoimmune diseases with complex symptoms and pathogenesis that are still not completely understood. Several studies showed that the trace element homeostasis and also the levels of antioxidant plasma proteins are changed in autoimmune disorders; however, these results are controversial. In this study, the potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), and iron (Fe) concentrations of the serum and proteins—immunoglobulin G (IgG), transferrin (Trf), albumin (Alb), and ceruloplasmin (Cp)—separated from serum samples by affinity chromatography were determined in patients with SLE and SS. Ca and K levels were found to be decreased in the case of both disorders compared to the control group, and the competitive antagonism of Cu and Zn was also observed: elevated Cu concentration together with a lower Zn concentration was measured in the sera of patients with autoimmune diseases. After fractionation, the trace element concentration of protein containing fractions altered to that of the control group. In case of the autoimmune disorders, the highest Cu concentration was determined in the Alb-containing protein fractions while the Zn level decreased in the Alb and increased in the Cp as well as in the IgG- and Trf-containing fractions compared to the healthy samples. Changes have also been found in the level and distribution of K and Ca.

We have developed a chromium speciation and preconcentration method with the use of the graphite furnace atomic absorption spectrometry (GFAAS) technique. This method is based on single-drop microextraction (SDME) technique. Nowadays the microextractions have become popular, because low amount of organic solvent needs to be used for the separation. The sample was introduced into the extraction cell with a single chloroform droplet. For the separation and enrichment of chromium species, an ion-pair forming compound was used. After the extraction, the chromium content of the droplet was determined by GFAAS. The analytical sensitivity of the standard SDME technique was improved by increasing the volume of organic phase and by sample recirculation. Because of the increased contact area and the developed extraction device, the stability of droplet was markedly increased. As an application we have determined the r(VI) content of sea water by the GFAAS technique using these separation/enrichment methods. Under the optimized extraction conditions, the linear range, detection limit (S/N = 3) and precision (RSD, n = 3) for Cr(VI) were 0.14 - 5.00 μg/L, 0.042 μg/L, and ≤ 3.0%, respectively. The advantages of this method are the following: cost efficiency, the high enrichment of chromium species and easy usage with the GFAAS technique. Therefore the concentration of the chromium species can be determined at the ng/L level.

In the present paper we suggest a novel calibration method of the model for hydrodynamic and contaminant transport using the example of a sewage disposal site set up uninsulated in a sandy environment. With the hydrodynamic model we applied time-dependent model calculations in order to fit the individual hydrodynamic parameters. For the calibration of the transport model, sodium was chosen, which has a negligible retardation factor. We demonstrated that this approach is suitable for creating a model that provides calculated results comparable to the actually measured, experimental ones. The created model proved to be appropriate for use in the estimation of the maximal spatial extension of the contamination, which—in the case of the investigated sewage disposal site—was found to be 0.1 km 2 in the near-surface (1–3 m deep) layers, whereas it was three times higher at a depth of 40–60 m.

Many social celebrations in urban areas are followed by fireworks show. The organic and inorganic pollutants emitted during detonations are expected to affect the ambient air quality of these celebration sites. The environmental aspects of fireworks events are usually investigated by analyzing the concentration and composition of airborne particulate matter, while there is limited information regarding the effect of fireworks on the elemental concentration of deposited dust. In this study, foliage dust samples were collected in the city of Debrecen (Hungary) before and after the fireworks show, organized on the 20th of August for the celebration of a historical event. Leaf samples (Tilia tomentosa) were collected around the location of the area of festivities. The sampling sites were further divided into five areas: city center (center), Southeast (SE), Southwest (SW), Northeast (NE), and Northwest (NW). We found that the amount of deposited dust particles increased significantly after the fireworks show compared to the background; we also found significant differences in the amount of dust deposition between the different locations of the city. A statistically higher level of Ca, Mg, and Sr was detected in samples collected after the display compared to those collected during the previous days, while the concentration of other studied elements were not statistically different from the background level. Our study confirmed previous findings that the relatively high altitude of detonations allows chemicals to disperse in the fine and ultrafine aerosol fractions; thus, the emitted pollutants by fireworks shows do not increase the level of elements as markedly in deposited dust as in the inhalable fraction.

Atomization of cadmium compounds (acetate, chloride, nitrate, perchlorate, sulfate, formate, propionate) was studied using flame atomic absorption spectrometry. Our goal was to study processes influencing atomization separately, the focus was on the contribution of thermal properties of substances to atomization. For this purpose new techniques and equipment have been developed, such as a special separated three-slot burner, quartz flame furnace, and an electrically heated thermospectrometer. According to quartz flame furnace and thermospectrometric measurements, cadmium salts do not atomize below 600 °C in an inert atmosphere. We found that in the thermospectrometer the atomization of cadmium compounds follows at least two different reaction courses. At lower temperatures (650–700 °C) a slower mechanism is dominant at higher regions of the furnace, while at 800 °C a faster mechanism demanding less residence time in the furnace becomes dominant. Under inert atmosphere the degree of atomization strongly depends on the thermal properties of substances.

Cobalt is a naturally occurring element in the aquatic environment and is essential for many living functions of vertebrates. The role, retention and interactions of cobalt with other trace elements in the marine fish nutrition have been poorly documented. In this study the accumulation and effect of cobalt was investigated on the survival and larval growth of barramundi, Lates calcarifer, when fed individually and combined with zinc and manganese through a nourishment organism. Barramundi larvae from 14 to 30dph were fed with Artemia nauplii in nine treatments (n=3): without enrichment (control), enriched with 50mgL−1 and 100mgL−1 CoCl2 (Co-1 and Co-2), MnCl2 (Mn-1 and Mn-2), CoCl2 along with MnCl2 (CoMn-1 and CoMn-2) as well as CoCl2 along with ZnSO4 (CoZn-1 and CoZn-2) respectively. All treatments had significant effect on the cobalt, manganese and zinc level of Artemia. The concentration of these elements increased in parallel with the dose of supplementations. Our results show that a significantly higher growth performance of barramundi larvae can be achieved when cobalt and manganese supplementation is applied. No interaction occurred between the retention of zinc and cobalt, but a competitive type of interaction is assumed between the deposition of cobalt and manganese in barramundi larvae. Combined treatments of cobalt and manganese increased cannibalism and mortality significantly, while other treatments had no significant effect on the survival of barramundi. Redundancy analysis showed a strong correlation between the cobalt and manganese concentration of Artemia and barramundi larvae, as well as a total agreement between the zinc concentration of the zooplankton and the larvae.

Highly forsteritic olivine (Fo: 99.2–99.7) in the Kaba meteorite emits bright cathodoluminescence (CL). CL spectra of red luminescent forsterite grains have two broad emission bands at approximately 630 nm (impurity center of divalent Mn ions) in the red region and above 700 nm (trivalent Cr ions) in the red–IR region. The cores of the grains show CL blue luminescence giving a characteristic broad band emission at 400 nm, also associated with minor red emissions related to Mn and Cr ions. CL color variation of Kaba forsterite is attributed to structural defects. Electron probe microanalyzer (EPMA) analysis shows concentrations of Ca, Al, and Ti in the center of the forsterite grain. The migration of diffusible ions of Mn, Cr, and Fe to the rim of the Kaba meteoritic forsterite was controlled by the hydrothermal alteration at relatively low temperature (estimated at about 250 °C), while Ca and Al ions might still lie in the core. A very unusual phase of FeO (wüstite) was also observed, which may be a terrestrial alteration product of FeNi‐metal.

Barramundi (Lates calcarifer) is a predatory fish species native in Southeast Asia and Australia. Based on the geothermal potentiality of Hungary the high market potential warm-water fish barramundi can be produced economically. Living nourishment organisms such as Artemia nauplii play an essential role in the larval rearing of barrramundi. However, zooplanktons in natural aquatic enviroments contain minerals in a higher concentration than the usually fed newly hatched Artemia. Therefore the goal of recent study was to investigate the effect of cobaltchloride on the larval growth and survival of barramundi when fed individually and combined with Zn and Mn supplemented Artemia. In our experiment a 24 hours period was used for the enrichment of newly hatched Artemia nauplii with cobalt chloride in itself, as well as in combination with zinc sulphate and manganese chloride. A total of 1900 barramundi larvae from 15–30 day post hatching were fed with supplemented Artemia in 9 groups of treatments in duplicate. The growth performance and elemental concentration of 40 larvae from each group was determined. All the groups produced significantly improved growth compared to the control (p<0.05). The lower concentration of individual Co supplementation resulted in a higher growth performance while the opposite dose relation occured when combined the Co with Mn. Cobalt had a significant negative effect on the Mn uptake of the larvae – significantly higher Mn accumulation compared to the control group was only observed when Mn was fed in itself (p<0.05). In case of Co-Zn-1 and Co-Zn-2 treatments significantly higher Zn concentration was measured than in the others (p<0.05).

A novel procedure for the determination of Cr(VI) using electrothermal atomic absorption spectrometry with Zeeman background correction was developed. The method is based on the reaction of Cr(VI) with dimethyl indocarbocyanine (DIC) in acidic medium in the presence of chloride ion followed by liquid-liquid extraction of the ion associate formed and subsequent GFAAS detection. The optimum conditions (pH, concentrations of chloride ion and DIC) were determined for the extraction of Cr(VI) into toluene. Furthermore, the effect of temperature on the separation, the stability of the complex formed, possibilities of preconcentration and possible interference of Fe, Cd, Co, Ba, Al, Hg, Zn, Ni, Cu, V, Mn and Pb were studied as well. The detection limit (LOD) of the method for Cr(VI) was found to be 0.25 mu g L-1 and RSD was mostly better than 5% using a 1 : 1 ratio for the organic and water phases.

Dust samples needed for the research was put at our disposal in great amount by the DKCE power station of Debrecen. In the station dust filtration of air takes place in more steps, which provides us strained of on the coarse filters in the range of 2000 μm to 10 μm, while between 10 μm to 1 μm on the fine filters. Those particles that manage to get across the filter system can be collected by the off-line washing of the turbine area. This fraction will contain fragments which are particular concern to human health as they can not only get into the lung but can attach to the alveoli. Dust sample collected in the city centre, nearby a railway station and a congested vehicular bridge contains all the contaminants that are imposed on the inhabitants of a typical big city. It is established from the size range distribution of samples collected from the coarse filters that almost 90% of the particles are under 63 μm. We determined the chemical composition of dust by using highly sensitive analytical methods after setting aside the most appropriate sampling and preparatory processes. By the side of the inorganic components, dust samples contain pollen and smut particles in higher amount, as well as spherules.

A reaction based on ion associate formation between dimethylindodicarbocyanine polymethine dye 1,3,3-trimethyl-2-[5-(1,3,3-trimethyl-1,3-dihydroindol-2-ylidene)-penta-1,3-dienyl]-3H-indolium (DIDC) and Cu(I) in the presence of chloride ions as ligand is used to develop a liquid-liquid extraction procedure for the separation and preconcentration of copper with subsequent graphite furnace atomic absorption spectrometric detection. The optimum reaction conditions for ion associate formation and extraction were found to be: pH 3-5, 0.24-0.36 mol L(-1) of chloride, 0.05-0.12 mmol L(-1) of DIDC, amyl acetate as extraction solvent, an aqueous to organic phase ratio of 5 : 1 mL : mL. A linear response was obtained in the range 0.4-4.8 mu g L(-1) of Cu, and the limit of detection, calculated from a regression equation based on three times the standard deviation of the blank, was 0.10 mu g L(-1). The method was applied to the determination of Cu in real samples. It is important to note that the presented method can also be applied to the determination of Cu(I) in the presence of a 125-fold excess of Cu(II), thus enabling the speciation analysis.

We have worked out several chromium speciation and pre-concentration methods with the use of the GFAAS technique. These methods were based on classical and continuous liquid-liquid extraction techniques using a patented continuous extraction device. For the separations and enrichments of chromium species was used ion-pair compound. As an application we have determined the Cr(III) and Cr(VI) content of water using these separation/enrichment methods and the GFAAS technique. The advantage of these methods is the cost effectiveness, high chromium species enrichment and easy use with GFAAS technique, therefore the concentration of the chromium species can be determined at the ng/L level.