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  • Author or Editor: A. Mészáros x
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In this study sap flow dynamics of mature sessile oak trees (Quercus petraea) in a marginal sessile oakturkey oak forest was investigated in 2009. That year spring was dry without significant rain in April and May and the driest month was August. Due to the extreme weather conditions the volumetric soil water content (SWC) of upper 30 cm was low on experimental days in May (0.13–0.14 cm3 cm−3) but it reached the lowest value in August (0.08 cm3 cm−3). Sap flow was measured in a dominant and a co-dominant tree by heat dissipation method from 26 March till 30 October. In the present paper several three-day long periods of the continuous seasonal recordings were chosen to represent the effects of typical weather conditions and different stages of canopy development on sap flow dynamics. The daily maximum sap flow density values of dominant and co-dominant trees were similar (0.30–0.32 cm3 cm−2 min−1) in moist period (July). Rains and transient increase of SWC after proceeding drought resulted in change of diurnal course of sap flow in experimental days of July. In this period dominant trees also showed considerable sap flow (0.19 cm3 cm−2 min−1) during night hours and short sap flow peaks in early morning (6:00 to 8:00 a.m.) indicating the refilling of desiccated tissues. After the progressive drought in August the daily maximum sap flow density decreased to 0.07 cm3 cm-2 min-1 in dominant tree and to 0.12 cm3 cm−2 min−1 in the co-dominant. Both trees exhibited gradual stomatal closure from morning hours.

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Acta Physiologica Hungarica
Authors:
G Mészáros
,
Cs Orbán
,
A Kaposi
,
G Toldi
,
B Gyarmati
,
T Tulassay
, and
Prof. Barna Vásárhelyi

Mitochondrial functions have a major impact on T-cell functionality. In this study we characterized whether mitochondrial function in the neonatal T-cells differs from that in the adult T-cells during short T-cell activation. Methods: We used fow cytometry methods to test mitochondrial mass and to monitor mitochondrial Ca2+ levels, mitochondrial potential and superoxide generation in parallel with cytoplasmic Ca2+ levels during phythohaemagglutinine-induced activation of CD4+ and CD8+ T-cells of 12 term neonates and 11 healthy adults. Results: Baseline mitochondrial mass of CD4+ and CD8+ cells was lower in the neonate than in the adult. In comparison with the adult, neonatal resting CD4+ T-cells had lower cytoplasmic Ca2+ levels and this was associated with normal activation induced Ca2+-response. During short-term activation cytoplasmic Ca2+-response was lower in neonatal than in adult CD8+ T-cells. Mitochondrial Ca2+ uptake was increased in CD4+ neonatal T cells while it decreased in CD8+ T-cells. Mitochondrial depolarization was increased in CD4+ and decreased in CD8+ neonatal T-cells compared to adults. Superoxide generation was higher and equal in neonatal CD4+ and CD8+ cells, respectively, compared to the adult ones. Conclusion: Our data suggest that neonatal T-cells exhibit marked differences in mitochondrial function and superoxide generation compared to adult T-cells.

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Acta Alimentaria
Authors:
Á. Koncz
,
L. Mészáros
,
J. Farkas
,
K. Pásztor-Huszár
,
R. Helt
, and
N. Lechner

Thermal and HHP treatments were compared. We established that the applied HHP treatments reduced the total cell count more significantly than thermal treatments. For example, the 10 min 600 MPa/10 min HHP treatment was equivalent to about 10 min thermal treatment at 70 °C. This combination of temperature and time is not used in the pasteurisation practice of the dairy industry. The various thermal treatments reduce the phosphatase enzyme activity to between one-third and one-hundredth of the original activity. The HHP treatments yielded similar results. Six hundred MPa pressure caused 10 to 70% decrease in the enzyme activity, while 700 MPa pressure led to a decrease of one log cycle.In the second year we tried to investigate the kinetics of the effect of HHP treatment. The 5, 10, 20, 40 min holding times were systematically applied in the range of 400 to 700 MPa. According to the results, 600 and 700 MPa HHP treatments effectively assured a decrease in the total cell count and the alkaline phosphatase enzyme activity. No organoleptic changes occurred.

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Acta Alimentaria
Authors:
Y. Hassan
,
L. Mészáros
,
A. Simon
,
E. Tuboly
,
Cs. Mohácsi-Farkas
, and
J. Farkas

The total viable cell count of bacteria in vacuum-packaged chilled minced beef has been decreased equally, by approx. two log-cycles, as an effect of 1.5-2.0 kGy gamma radiation or 200-300 MPa high hydrostatic pressure (UHP) treatment for 20 min. Coliform bacteria could be eliminated to non-detectable levels by the same treatments. The shelf-life of both untreated and non-thermally pasteurised samples were limited mainly by growth of lactic acid bacteria. At about equal bactericidal effect, more drastic changes of texture and colour occurred in UHP-pasteurized minced beef samples than in the radiation-pasteurized ones. Whereas radiation pasteurisation caused minimal changes in appearance, texture and DSC-thermograms of minced beef, UHP-pasteurisation of the raw samples proved to be strongly discolouring by denaturing the muscle pigments and causing extensive denaturation of the myofibrillar proteins. The water holding capacity of irradiated samples decreased, while that of high pressure treated ones increased as compared to the untreated control. Near infrared spectrometry and electronic nose measurements gave promising results to make distinctions non-destructively on changes of various physical-chemical changes and quality parameters as a function of pasteurising treatments and/or storage.

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Purpose

Reduced functional mobility is a risk factor for falls. The Timed Up and Go test is a complex measurement tool for functional mobility. Our aims were to assess the functional mobility of: (a) community-living elderly who were participating in an exercise programme (n = 40; mean age = 73.7 years), (b) community-living elderly who were physically inactive (n = 40; mean age = 74.1 years), and (c) institutionalized elderly (n = 40; mean age = 73.5 years) and to compare the results with cut-off values for risk of fall.

Materials and methods

After measuring functional mobility, one-way independent ANOVAs and sample t-tests were used for analysis.

Results

The functional mobility of the active participants was better than that of the inactive (p < .001) and institutionalized participants (p < .001). There was no significant difference between the inactive and institutionalized participants (p = .990). The functional mobility of the active participants was better, whereas the functional mobility of the inactive participants was worse than the cut-off value of 13.5 s for risk of fall for community-living elderly. The functional mobility of the institutionalized participants did not differ from the 15-s reference value for predicting risk of fall.

Conclusion

The results indicate that regular physical activity has a positive effect on maintaining functional mobility among both community-living and institutionalized elderly individuals.

Open access
Acta Physiologica Hungarica
Authors:
Krisztina Rusai
,
A. Prokai
,
C. Juanxing
,
K. Meszaros
,
B. Szalay
,
K. Pásti
,
V. Müller
,
U. Heemann
,
J. Lutz
,
T. Tulassay
, and
A. Szabo

Previous experimental data suggest that steroids might have protective effects during hypoxic/ischemic injury of various organs. In this study, the association between dexamethason (Dexa) treatment and the anti-apoptotic SGK-1 was tested in ischemic renal injury. In vitro, HK-2 cells were exposed to 24 h hypoxia, and the effect of Dexa incubation on SGK-1 expression / activation and on cell death was studied. In an in vivo rat model of unilateral renal IR, animals were treated with Dexa, and serum renal function parameters, tissue injury and SGK-1 expression and localization were examined after different reperfusion times (2 h, 4 h and 24 h). Dexa at a dose of 2 mg/L exerted a protective effect on cell survival assessed by LDH release and vital staining paralleled by marked up-regulation of SGK-1. In rats, 2 mg/kg Dexa treatment 24 h prior to ischemia resulted in less severe tissue injury and ameliorated urea nitrogen levels 24 h after reperfusion. Furthermore, SGK-1 expression and phosphorylation were higher in Dexa animals demonstrated by Western blot and immunofluorescence technique. Our results provide novel data on the signalling mechanism of Dexa under hypoxia / ischemia and further support that Dexa emerges as an attractive pharmacological agent for the prevention of ischemic injury.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Z. Németh
,
Z. Homonnay
,
F. Árva
,
Z. Klencsár
,
E. Kuzmann
,
J. Hakl
,
K. Vad
,
S. Mészáros
,
K. Kellner
,
G. Gritzner
, and
A. Vértes

Abstract  

In this paper we present 57Co emission Mössbauer and AC magnetic susceptibility studies of La0.8Sr0.2CoO3-δ perovskite. The observed coexistence of paramagnetic and magnetic subspectra in the 57Co emission Mössbauer spectra, as well as the difference of their isomer shifts support the existence of electronic phase separation in this perovskite, in good agreement with the double exchange based cluster model.

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Acta Phytopathologica et Entomologica Hungarica
Authors:
Á. Szabó
,
G. Ripka
,
Zs. Hajdu
,
B. Tempfli
,
M. Varga
,
I. Mészáros
,
Cs. Kutasi
,
T. Németh
, and
B. Pénzes

The authors give account of 7 new species, viz. Proctolaelaps striatus (Westerboer, 1963), Hypoaspis kargi Costa, 1968, Hypoaspis fishtowni Ruf and Köhler, 1993, Neoseiulus zwölferi (Dosse, 1957), Euseius stipulatus (Athias-Henriot, 1960), Neoseiulus subtilisetosus (Beglyarov, 1962), Neoseiulus pepperi (Specht, 1968) belonging to the order Mesostigmata, which have not been recorded so far in the Hungarian fauna.

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Cereal Research Communications
Authors:
T. Tóth
,
T. Németh
,
A. Bidló
,
F. Dér
,
M. Fekete
,
T. Fábián
,
Z. Gaál
,
B. Heil
,
T. Hermann
,
E. Horváth
,
G. Kovács
,
A. Makó
,
F. Máté
,
K. Mészáros
,
Z. Patocskai
,
F. Speiser
,
I. Szűcs
,
G. Tóth
,
Gy. Várallyay
,
J. Vass
, and
Sz. Vinogradov
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