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  • Author or Editor: István Farkas x
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This article presents an analysis and catalogue of Roman stamped tiles discovered in Dunaszekcso (Baranya county, Hungary) and serves as a preliminary report on the excavation conducted on the kilns in September 2012.

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The efficiency of photovoltaic modules and their performance depends on the value of irradiation and on the temperature of the module. The temperature of the modules can be reduced with the suitable set-up of the modules giving an opportunity to the natural (buoyancy driven) flows for cooling the PV modules. Present work is aimed at defining the heat transfer coefficients of the modules, using the methods of the computational fluid dynamics. The heat transfer coefficients are defined at the typical placements of modules and in the case of average wind speeds typical in Hungary. Such values could be used to define the accurate working temperature.

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There is a clear need for application of proper methods for measuring food quality and safety in the globalized food-webs. Numerous instrumental methods have been established in the course of the 20th century and are developing further, together with data analysis techniques, for such purposes. Among them, near-infrared and fluorescence spectroscopic methods and chemical sensor arrays called electronic noses show particular promise for rapid, non-destructive, non-invasive and cost-effective ways for assessing changes and enhancing control during processing and storage of foods. Their key advantages as analytical tools are 1) their relatively high speed of analysis, 2) the lack of a need to carry out complex sample preparation or processing, 3) their relatively low cost, and 4) their suitability for on-line monitoring or quality control. The present survey attempts to demonstrate examples from the above areas, limiting itself mainly to monitoring some quality indices which contribute to the functionality or acceptability of foods as affected by alternative processing technologies, or loss of freshness/microbial safety, or developing spoilage during storage and marketing. These instrumental methods are correlative techniques: they must be calibrated first against (traditional) reference properties, and the instrumental data are evaluated with the help of chemometric methods. Near-infrared (NIR) spectroscopy can be used in either the reflectance or the transmittance mode. NIR spectra transformed to mathematical derivatives allows subtle spectrum changes to be resolved. Selected examples from the extensive NIRS literature relate to assessment of the quality of frozen fish, predicting cooking loss of chicken patties, detecting complex physico-chemical changes of minced meat as a function of the intensity of high hydrostatic pressure treatment, comparing changes of NIR spectrometric “fingerprints” caused by gamma radiation or high pressure pasteurization of liquid egg white. Changes of NIR spectra reflect several parameters which suit the evaluation of loss of freshness, and onset of spoilage of various foods. NIR spectroscopy shows an application potential for rapid detection of bacterial or mould contamination. It may serve as a tool for detecting initial stages of mobilization processes during germination of cereal grains, or even for GMO screening. Spectrofluorometic measurements have shown potential, e.g. to monitor lipid oxidation and development of meat rancidity, to differentiate between raw and processed milks, and to monitor fish and egg freshness. Electronic noses containing chemical sensor arrays offer a rapid method for evaluation of head-space volatiles of food samples, important for characterizing quality and safety. Such gas sensors may be able to classify storage time, and determine spoilage, either earlier or at the same time as the human senses, or “sniffing out” bacterial pathogens or (toxigenic) fungal growth on certain foods. Electronic nose sensing is also a promising method for detecting quality changes of fruit- and vegetable products non-destructively. In relation to some examples to be presented in the paper, certain software developments as qualitative classification tools made by Hungarian scientists will be pointed out.

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Authors: István Háber, István Kistelegdi, Tamás Bötkös and István Farkas

The most common way to measure solar radiation is the horizontal global irradiation measured by a pyranometer. To use the collected data in photovoltaic energy-yield prediction a mathematical model can be made from average data’s of more years. These global horizontal values to be used on tilted surfaces like a solar module, should be transformed, according to the incident angle of the solar beam. But there is a diffuse component also, which has to be determined, because it should be transformed in different way. This work is a case study, where data modeling and the transformation process will be shown using the data collected for Pecs/Hungary, and transformed for an existing site on Komlo, the RATI Ltd’s zero energy factory and also a LabView program has been made based on these data, to be used in the complete ‘heat transfer based photovoltaic-yield model’.

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Authors: Erika Orosz, Ágnes Farkas and István Kucsera

Acanthamoeba species are free-living amebae that can be found in almost every range of environments. Within this genus, numerous species are recognized as human pathogens, potentially causing Acanthamoeba keratitis (AK). AK is a corneal disease that is predominantly associated with contact lens use, the epidemiology of which is related to the specific genotype of Acanthamoeba. This study reports seven (7/16; 43.75%) positive cases. Detection of Acanthamoeba in corneal scrapings is based on cultivation and polymerase chain reaction (PCR) combined with the molecular taxonomic identification method. By PCR, seven samples were positive; cultivation was successful for five samples, probably because of the low quantity of samples. Genotype identification was carried out with a real-time fluorescence resonance energy transfer PCR assay based on sequence analysis of the 18S rRNA gene, and sensitivity and specificity were evaluated in comparison with traditional parasitological techniques. All seven detected Acanthamoeba strains belonged to the T4 genotype, the main AK-related genotype worldwide. These results confirmed the importance of a complete diagnostic protocol, including a PCR assay, for the clinical diagnosis of AK from human samples. Genotyping allowed the identification of all isolates in the T4 group, thus demonstrating the prevalence of this genotype in Hungary.

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Authors: Erika Orosz, Katalin Perkátai, Beatrix Kapusinszky, Ágnes Farkas and István Kucsera

Simple real-time PCR assay with one set of primer and probe for rapid, sensitive qualitative and quantitative detection of Entamoeba histolytica has been used. Consensus sequences were used to amplify a species-specific region of the 16S rRNA gene, and fluorescence resonance energy transfer hybridization probes were used for detection in a LightCycler platform (Roche). The anchor probe sequence was designed to be a perfect match for the 16S rRNA gene of Entamoeba species, while the acceptor probe sequence was designed for Entamoeba histolytica, which allowed differentiation. The performed characteristics of the real-time PCR assay were compared with ELISA antigen and microscopical detection from 77 samples of individuals with suspected clinical diagnosis of imported E. histolytica infection. Stool and liver abscess pus samples were examined with analytical sensitivity of 5 parasites per PCR reaction. The melting curve means Tms (standard deviation) in clinical isolates were 54°C. The real-time assay was 100% sensitive and specific for differentiation of Entamoeba histolytica, compared with conventional ELISA or microscopy. This real-time PCR assay with melting curve analysis is rapid, and specific for the detection and differentiation of Entamoeba histolytica. The suitability for routine use of this assay in clinical diagnostic laboratories is discussed.

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Authors: Mária Papp, Anikó Farkas, Miklós Udvardy and István Tornai

A bakteriális infekciók a májcirrhosis jól ismert szövődményei, jelentősen emelik a mortalitást. A májelégtelenség súlyossága és a gastrointestinalis vérzés fontos hajlamosító tényezők. A leggyakoribb fertőzések a spontán bakteriális peritonitis, a húgyúti és légúti fertőzések, valamint a sepsis. A kórokozók között azonos arányban fordulnak elő Gram-negatív és -pozitív baktériumok. Gastrointestinalis vérzés esetén (varix vagy nem varix eredetű) az ascites meglététől vagy hiányától függetlenül rövidtávú profilaktikus antibiotikus kezelés (per os norfloxacin vagy ciprofloxacin) javasolt (primer prevenció) . A kórházi kezelés ideje alatt gastrointestinalis vérzés hiányában is megfontolandó a norfloxacin adása alacsony ascites proteintartalom esetén. A spontán bakteriális peritonitis empirikus kezelésében iv. III. generációs cephalosporin adása javasolt, mely a tenyésztési lelet alapján célzott antibiotikus kezelésre váltható. A kezelés időtartama 5–8 nap. Jó alternatíva lehet az amoxicillin/klavulánsav kombináció, valamint korábban spontán bakteriális peritonitis profilaxisban nem részesülő betegek esetén valamely kinolonszármazék is. Az iv. megkezdett antibiotikus kezelés megfelelő klinikai javulás mellett 2 nap múlva per os kezelésre váltható. Veseelégtelenség társulása esetén kiegészítő albuminkezelés szükséges. Hosszú távú antibiotikum-profilaxis a spontán bakteriális peritonitis epizód lezajlását követően a gyakori kiújulás veszélye miatt minden betegnél indokolt (szekunder prevenció) . A „szelektív intestinalis dekontaminációra” leginkább a per os adott, elsősorban rosszul felszívódó fluorokinolonszármazék, a norfloxacin javasolt. A per os adott ciprofloxacin vagy méginkább a levofloxacin, ez utóbbi Gram-pozitívak ellen is hatékony, megfelelő alternatíva lehet. Trimetoprim/sulfamethoxazole adása csak abban az esetben jön szóba, ha a beteg nem kaphat kinolonszármazékot. A kezelést az ascites eltűnéséig; az ascites perzisztálása esetén a beteg élete végéig vagy a májtranszplantációig kell folytatni. A rezisztens törzsek kialakulásának veszélye miatt hosszútávú profilaxis spontán bakteriális peritonitisen még át nem esett asciteses cirrhosisos betegekben nem javasolt, akkor sem, ha az ascites terápia refrakter, vagy pedig fehérjetartalma alacsony.

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