Authors:J. Varga, R. Kiss, T. Mátrai, T. Mátrai, and J. Téren
Ochratoxin A is a mycotoxin produced by Aspergillus and Penicillium species. This mycotoxin is a common contaminant of various food products including cereal products, spices, dried fruits, coffee, beer and wine. Besides cereal products, beer and wine contribute significantly to ochratoxin exposure of humans. We examined the ochratoxin content of Hungarian wines and beers using an immunochemical technique. The detection limit of this technique is 0.01mg l-1. Altogether 65 wine and 25 beer samples were analysed. The presence of ochratoxin A was confirmed by HPLC in positive samples. Ochratoxin A was detected in 97.7% of wines, with ochratoxin concentrations ranging from 0 to 0.533mg l-1. The mean ochratoxin A concentration in wines was 0.110mg l-1. Only one of the Hungarian wines examined contained more than 0.5mg l-1ochratoxin A, the previously suggested EU limit for wine. Our data indicate that red wines are more frequently contaminated, and have higher mean ochratoxin contamination (0.117mg ml-1) than white wines (0.0967mg ml-1), in accordance with previous observations. A North-South gradient in wine ochratoxin concentrations is not evident from our data. For beers, all but one of the samples was found to be contaminated with small amounts of ochratoxin A with a mean concentration of 0.127mg l-1(range: 0.030-0.250mg l-1). Only one of the beers contained ochratoxin A above 0.2mg l-1, the anticipated European Community maximum allowable limit in beer. We could not detect correlation between the type and origin of beer and ochratoxin contamination.
Authors:R. Marinkovic-Neducin, E. Kiss, T. Cukic, and D. Obadovic
The purified bentonite parent clay, fraction ≤; 2 mm of montmorillonite type, has been pillared by various polyhydroxy cations,
Al, AlFe and AlCu, using conventional pillaring methods. The thermal behavior of PILCs was investigated by combination of
X-ray diffraction (XRD), thermal analysis (DTA, TG) and low temperature N2 adsorption/desorption (LTNA). Thermal stability
of Al-, AlFe- and AlCu-PILC samples was estimated after isothermal pretreatment in static air on the temperatures 300, 500,
600 and 900C. Crucial structural changes were not registered up to 600C, but the fine changes in interlayer surrounding
and porous/microporous structure being obvious at lower temperatures, depending on the nature of the second pillaring ion.
AlFe-PILC showed higher thermal stability of the texture, the AlCu-PILC having lower values and lower thermal stability concerning
both overall texture and micropore surface and volume. Poorer thermal stability of AlCu-PILC sample at higher temperatures
was confirmed, the presence of Cu in the system contributing to complete destruction of aluminum silicate structure, by 'extracting'
aluminum in stabile spinel form.
Authors:D. Kiss, R. Zelkó, Cs. Novák, and Zs. Éhen
The purpose of the present
work was to study the compatibility of metronidazole with different pharmaceutical
excipients (hydroxypropyl methylcellulose, poly(ethylene oxide), microcrystalline
cellulose, dicalcium phosphate dihydrate, and anhydrous dicalcium phosphate)
using differential scanning calorimetry and diffuse reflectance spectroscopy.
Dicalcium phosphate dihydrate was the only excipient that showed interaction
with metronidazole even before storage. Changes referring to a possible transition
to dihydrate form were observed in the thermal curves of anhydrous dicalcium
phosphate after four weeks of storage. Although dicalcium phosphate dihydrate
can be replaced by the anhydrous form in pharmaceutical formulations, the
observed transition might negatively influence the stability of dosage forms.
Authors:Andrea Bistyák, S. Kecskeméti, R. Glávits, I. Tischler, S. Nagy, G. Kardos, and I. Kiss
An epizootic of Pacheco’s disease is reported from a zoo bird population. The infection was introduced by wild-captured Patagonian conures (
) despite 61 days of quarantine. The disease affected several parrot species and, interestingly, three out of seven bearded barbets (
). The mortality rate was 30.93%. Autopsy revealed abdominal hyperaemia with liver haemorrhages and, in less rapid cases, yellowish discoloration and fragility of the liver. Death was caused by the collapse of circulation. Histopathology demonstrated liver cell necrosis, disintegration of the lobular structure, and a few intranuclear inclusion bodies. Icosahedral virions were detected by electron microscopy. The virus was isolated in the allantoic cavity of embryonated chicken eggs as well as in chicken embryo fibroblast cell culture. A 281-bp-long fragment of psittacid herpesvirus DNA was detected by PCR in cell culture material and liver samples of the affected birds. To our knowledge this is the first report of Pacheco’s disease in bearded barbets as well as the first occurrence of Pacheco’s disease in Hungary.
Authors:G. Ripka, G. Princzinger, I. Zsellér Hatala, László Vasas, B. Tóth, J. Kiss, and C. R. Edwards
The Hungarian plant protection organization has been performing western corn rootworm moni- toring over the past four years.In 1998 three different trapping activities were carried out at 150 monitoring sites.Hungarian pheromone traps and Multigard ®(yellow sticky)traps were used from July 1 to September 30.The number of catches and the average catches/trap in 1998 were lower than the catch numbers in 1997. In 1998,the pest spread to a lesser degree than in 1997.
Authors:Gy. Barna, J. Kiss, C. Gerber, L. W. Bledsoe, and C. R. Edwards
WCR adults generally lay their eggs in maize and their larvae feed almost exclusively on maize roots (Smith,1966,Branson and Ortman,1967,1971,Branson and Krysan,1981,Levine and Oloumi- Sadeghi,1991).For this reason,farmers have accepted growing maize in rotation with soybean to manage WCR larval populations without the use of soil insecticides.Recently,in Northwest Indiana and East Central Illinois in the USA,western corn rootworm has adapted to the above management system (Gerber et al., 1997).A portion of WCR eggs is laid in soybean and in other crops like alfalfa.This behavioral change increases the potential for survival of WCR larvae the following year since most soybean fields are rotated to maize.During the summers of 1996,1997,and 1998 field studies related to this behavioral shift were conducted in northwestern Indiana.Eleven pairs of maize/soybean fields were selected for the study.During these sampling periods,WCR beetles were present in both maize and soybean.Empirical observations show that there were higher numbers of females in soybean when compared to maize.
Authors:R.V Salamon, É. Vargáné-Visi, Cs.D. András, Zs. Csapóné Kiss, and J. Csapó
The addition of synthetic CLA is a possible way in order to compose foods enriched with conjugated linoleic acids (CLAs). The most environmental friendly methods for CLA synthesis are based on microbial biosynthesis. With homogeneous catalysis using organometallic catalysts (Ru and Rh complexes) high (approximately 80%) yields were obtained with high selectivity related to bioactive isomers. The heterogeneous catalysis has the advantage that at the end of the reaction there is no need for a supplementary separation operation or recycling of the catalyst. In heterogeneous process, the maximum yield may even be higher than 90% and the selectivity remains quite high as the reaction conditions are optimized. The substrates for obtaining CLAs are, in general, linoleic acid or alkyl linoleates and the catalysis is acidic. The yield and the selectivity depend on the strength and the type of acidic sites, as well as on the size distribution of the particles. Beside the existing catalytic methods, a photocatalytic process with UV and visible light irradiation with iodine promoter can be applied.
Authors:Péter Rózsa, Gyula Szö?r, Zoltán Elekes, Bernard Gratuze, Imre Uzonyi, and Árpád Z. Kiss
Obsidian samples from different localities of various geologic settings (Armenia, Hungary, Iceland, Mexico, Slovakia and Turkey) were analyzed by particle induced gamma-ray emission (PIGE) technique and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Samples from Mexico and Iceland show higher alkali and REE content as well as higher Nb and Ta abundances than the other samples. Discrimination diagrams show samples from Mexico and Iceland to belong to WPG. The position of the samples from the Tokaj Mts is also definite, and it corresponds to the expectation (VAG or VAG+syn-COLG fields). Using a Li-B diagram the obsidian samples can be distinguished according to their geographic distribution. By means of a Ce-Ti diagram, obsidian from the Tokaj Mts can be divided into three groups that may correspond to the archeometrical C2E, C2T and C1 groups. Phenocrysts in the obsidian samples from the Tokaj Mts, and the Aragats Mts (Armenia) were detected and analyzed by micro-PIXE (proton induced X-ray emission) method. In this way silicate minerals (zircon, pyroxene, biotite, plagioclase feldspars), ore minerals (chalcopyrite, pyrrhotite, pyrite), and other non-silicate mineral (anhydrite) were identified.
Authors:R. Bažok, I. Sivčev, T. Kos, J. Igrc Barčić, J. Kiss, and S. Jankovič
Pherocon AM (PhAM) trapping and visual counting are two commonly used methods for identifying maize fields in the USA that contain a sufficient number of adult western corn rootworms (WCR), Diabrotica virgifera virgifera LeConte to cause economic root damage by larvae the following year. Therefore, the estimation of adult WCR population plays an important role in management decisions (rotation or treatment). The goals of this study were (1) to compare adult WCR data obtained by PhAM trapping to “whole plant count” data in different maize developmental stages, (2) to determine the period in which the data obtained by both methods show the highest correlation, (3) to determine the regression curve between capture of WCR on PhAM as an independent variable and number of WCR observed by visual plant count, and (4) to determine if the “whole plant count” method can serve as a substitution for PhAM trapping under European conditions. Three samplings were conducted in 2006 in 38 fields in Croatia and one sampling was conducted in 22 fields in Serbia. Sampling in Croatia was conducted when maize plants were in the R 65-69, R 73-77 and R 79-85 developmental stages according to BBCH identification keys of maize. Sampling in Serbia was conducted when maize plants reached R 69-71 developmental stages. Three to six PhAM traps were placed in each 0.5 to 4 ha maize field seven days prior to sampling. Visual counts were conducted on the same day as trap inspections. Adult WCR densities in the PhAM traps were correlated to adult densities on whole plants. Statistical analyses comparing the results of PhAM trapping with the visual “whole plant count” method showed that there is a significant medium to strong correlation between them. Correlation coefficients varied depending on the data used in the analysis. When sampling was conducted in the first half of August (maize developmental stages R 69-77), the correlation coefficients were the highest (r(R 6971) = 0.8677 and r(R 73-77) = 0.706). Coefficients of determination were the highest as well [r2(R 69-71) = 0.753; r2(R 73-77) = 0.4984]. Therefore, the most appropriate period for sampling is during the first half of August. At that time, the majority of the maize plants were between the R 69 and R 77 developmental stages. According to the results, 0.5–1 visually determined adult/plant corresponds to 40 adults/trap/week. This shows that both methods are equally useful for estimating the population densities of WCR in the Central European region.
Authors:E. Koltay, I. Rajta, Zs. Rajta, I. Uzonyi, J.R. Morales, and Á. Kiss
Aerosol samples collected around the Chilean site Lonquimay during major volcanic activities in January 1989 have been subjected to microPIXE measurements of 1 mm lateral resolution in the Debrecen Institute. Elemental concentrations relative to calcium have been determined for Al, Si, P, S, K, Sc, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Ba in 187 individual aerosol particles with the particle sizes between 15 mm and 1 mm. On the basis of a cluster analysis performed on the data set we defined eight clusters. Scatter plots for selected pairs of elements as Si/Al, K/Si, S/Cl, and Al/S elemental ratios that are considered as signatures characterizing types and mechanisms in volcanic eruption - have been compared with published data available in the literature for various volcanic sites.