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Open access

E. Kurin, N. Fakhrudin and M. Nagy

Beneficial effects of red wine polyphenols on cardiovascular health are well known. The aim of our research was an interaction study of four red wine polyphenols – resveratrol (R), quercetin (Q), kaempferol (KF) and isorhamnetin (IR) of their ability to activate endothelial NO synthase (eNOS) promoter when used alone and in equimolar mixtures. To determine their activity, we performed a luciferase reporter gene assay on EA.hy926 cells stably transfected with a luciferase reporter gene construct containing eNOS promoter. The Bradford assay was also performed to account the cytotoxicity and/or the cell number differences. The median effect equation, as an interaction analysis evaluating synergy or antagonism of the combinations was done according to mass-action law principle. Isobolographic method was performed on selected double mixtures and dose reduction index was calculated for all mixtures. All single polyphenols activated eNOS promoter. The EC50 values were in micromolar concentrations ranging from 3.44 μM (R2 = 0.96) for kaempferol to 9.89 μM for isorhamnetin (R2 = 0.94). All mixtures activated eNOS promoter, but their interactions varied from synergy (Q+R, Q+IR+KF, Q+R+KF and Q+R+IR+KF), through additive (R+IR+KF) to antagonistic interaction (R+IR, R+KF, Q+IR, Q+KF, IR+KF and R+Q+IR). In this study, we show for the first time that red wine polyphenols activated eNOS promoter when used alone and in mixtures with different type of interactions.

Open access

Enikő Csifo, Tímea Katona, Juliánna Arseni, E. Nagy, I. Gergely and Ö. Nagy

Abstract

Objectives: Study of circulating and synovial levels of osteocalcin, osteoprotegerin and tumor necrosis factor-alpha (TNF-α) in patients with different stages of knee osteoarthritis and correlation analysis of these parameters with disease severity.

Methods: We enrolled 20 patients with different stages of knee osteoarthritis. The IKDC score (International Knee Documentation Comittee, 2000) was determined for each patient. Based on these data patients were divided into two groups: group I (advanced osteoarthritis) and group II (early osteoarthritis). Serum and synovial fluid levels of osteocalcin, osteoprotegerin, TNF-α were determined.

Results: For the entire group the level of osteocalcin in the serum showed higher values than in the synovial fluid. We found statistically significant differences in the serum levels of osteocalcin between the two groups (group I: 2.18 ± 0.54 ng/ml, group II: 6.07 ± 1.98 ng/ml, p = 0.019). Serum and synovial osteocalcin in the whole study lot could not be correlated with the disease score, however we observed a tendency towards significant negative correlation between the serum osteocalcin and IKDC score for group I and between synovial osteocalcin and IKDC score in group II. In the entire group, synovial osteoprotegerin concentration was six times higher than the serum osteoprotegerin level (p <0.0001) and TNF-α showed higher circulating levels than local concentrations.

Conclusions: In the advanced osteoarthritis group the serum and synovial osteocalcin show lower values than in the early osteoarthritis group, which means that as the disease progresses, bone anabolism decreases. In the case of osteoprotegerin, no significant difference between the two groups was detected.

Open access

E. Nagy, V. Haş, I. Haş, A. Suciu and V. Florian

The influence of Fusarium ear infection on the maize yield and mycotoxin content (Transylvania-Romania)

Maize is the host for a large number of pathogens, which invade all of its organs from the germination until being harvest, ear and grain infection often persistent even during storage. Diseases, through their symptoms reduce significantly the quantity and the quality of yield, estimated between 7-17% but, in the favorable years for this disease, they can be much greater. Fusarium diseases reduce yield value and quality by massive accumulation of Fusarium mycelium biomass (about 85%) on grain and ears and by mycotoxin contamination such as deoxynivalenol (DON), zearalenone (ZEA) and fumonisins (FUM). In this paper are presented aspects regarding the reaction of some maize hybrids under Fusarium spp. natural and artificial infections; the effect of Fusarium ear infection on yield, grain chemical composition, and mycotoxin content; the correlation between ear rot disease degree and yield ability, starch, protein and fat content. ANOVA evidenced the significant influence of experimental factors: infection conditions with Fusarium spp., maize genotypes, and their interaction on expression of the disease degree, yield capacity, protein, starch, fat and DON content. Average yield losses ranged between 7,0-9,3% during the experimental period. The hybrids Turda Star and Turda Favorit were more resistant to Fusarium ear rot, and Turda 165 was the most susceptible one. The artificial infection of ear with Fusarium spp. determined significantly decrease of starch and fat content and increases the protein and DON content for the most part of maize hybrids. Between rot diseased kernels and DON content a positive correlation was determined.

Open access

E. Nagy, F. Kristaly, A. Gyenes and Z. Gacsi

Abstract

Interfacial intermetallic compounds (IMC) play an important role in Sn-Cu lead-free soldering. The size and morphology of the intermetallic compounds formed between the lead-free solder and the Cu substrate have a significant effect on the mechanical strength of the solder joint.

In the soldering process of Sn-Cu alloys, Cu6Sn5 intermetallic compounds are formed. The complex structural behaviour of Cu6Sn5 IMC is temperature- and composition-dependent and it is long since subject to scientific research. The Cu6Sn5 phase basically exists in two crystal structures: hexagonal η-Cu6Sn5 (at temperatures above 186°C) and monoclinic η’-Cu6Sn5 (at lower temperatures). In the presence of Ni in the solder, the η-η’ transformation does not occur, therefore, the η-Cu6Sn5 phase remains stable.

In this study the role of Ni in the (Cu,Ni)6Sn5 intermetallic compound in Sn-Cu lead-free solders was examined. Sn-Cu alloys with different Cu content (0.5 to 1 mass%) were modified through Ni addition. The morphology of the intermetallic compounds of the modified Sn-Cu alloys was investigated by optical microscopy (OM) and scanning electron microscopy (SEM), the IMC phases were examined with X-ray diffraction method (XRD).

Open access

A. Gyenes, M. Benke, N. Teglas, E. Nagy and Z. Gacsi

Abstract

According to the directives (RoHS and WEEE) adopted by the European Union, lead has been banned from the manufacturing processes because of its health and environmental hazards. Therefore, the development of lead-free solders is one of the most important research areas of the electronic industry. This paper investigates multicomponent Sn-Ag-Cu based lead-free solders with different compositions. The properties of the six-component Innolot (SAC+BiSbNi) and two low-Ag containing alloys were compared with the widespread used SAC307 solder. Microstructure investigations and X-ray diffraction measurements were performed to analyze and identify the formed phases, furthermore, tensile tests and microhardness measurements were executed to determine the mechanical properties of the examined solders.

Open access

Tímea Varga-Fekete, Katalin Felvinczi, Emese Kun-Bálint, A Puskás, E Nagy and Z Brassai

Abstract

Aims: The ankle-brachial index is an efficient tool for objectively documenting the presence of lower extremity peripheral artery disease. However, its applicability for detection of critical leg ischemia is still controversial. We proposed to determine the diagnostic accuracy of the ankle-brachial index for critical ischemia.

Materials and methods: Systolic blood pressure measurements for calculation of the ankle-brachial index were obtained in 90 patients with peripheral artery disease. Ankle-brachial index was computed in 3 different ways (using the lowest ankle pressure, the highest ankle pressure, and the mean of the ankle pressures), sensibility, specificity, positive and negative predictive value and overall accuracy for detecting critical ischemia were determined for each method. A value ≤ 0.4 was taken as cut-off point for critical leg ischemia. Prevalence of coronary and cerebrovascular atherosclerosis and conventional risk factors were also noted.

Results: Using the lowest ankle pressure for computing ankle-brachial index provided higher sensitivity, and lower specificity for detecting critical leg ischemia, using the highest pressure was less sensitive, but more specific, and the mean pressure index gave intermediate results. Overall accuracy was highest for the latest method. The prevalence of generalized atherosclerosis was high in peripheral artery disease, but we found no significant difference between the intermittent claudication and the critical ischemia group.

Conclusion: Ankle-brachial index measurements, regardless of the method used for calculation, cannot identify or rule out reliably critical leg ischemia. Peripheral artery disease confers an increased risk of cardiovascular disease regardless of symptom status or lower extremity perfusion severity.

Open access

E. D. Nagy, P. Torma and K. Bene

Abstract

One of the most often-used parameters that describes morphology and runoff from a watershed is the time of concentration (Tc). At gauged watersheds, Tc can be determined using rainfall and a runoff hydrograph, while for ungauged watersheds, empirical equations are used. A good initial estimate of Tc greatly improves the accuracy of runoff predictions. In our study, we applied 14 empirical equations to determine Tc. Tarján Creek, which is located in northeastern Hungary, was selected as the trial gauged watershed. It is located in a mountainous region with an area of 72 km2. The input parameters for the empirical equations were determined using geoinformatical tools. To evaluate the accuracy of the empirical equations, HEC-HMS was used to model the runoff. Using the measured runoff data, both continuous and event-based models were calibrated. For direct runoff, Clark’s unit hydrograph was selected. Tc is one of the input parameters for this model. After the calibration, the estimates from the empirical equations for Tc were compared to the HEC-HMS calibrated values for each subwatershed. The empirical estimates varied greatly. The Wisnovszky-equation, which is most often used in Hungary, underestimated Tc.