Search Results

You are looking at 1 - 10 of 16 items for

  • Author or Editor: J. B.Nagy x
Clear All Modify Search

The study area is the peaty bed of Navad-patak mire situated in the North-Eastern Alföld, on the Bereg plain, which is slightly investigated area. The purpose of our research was to reconstruct the recent vegetation dynamic processes of the mire from 1950 till 2005. Beside the aerial photos we used the ERDAS Imagination remote sensing program, and made digital photo interpretation. We divided the vegetation history into three parts. In the first period, the nutrient load of the mire was increased, peat decaying and foresting processes started, the open peat-moss dominated associations ( Eriophoro vaginati-Sphagnetum, Carici lasiocarpae-Sphagnetum ) were disappeared. In the second period the expansion of the forest vegetation continued, the species composition transformed, and the characteristic species of the mentioned associations ( Eriophorum vaginatum, E. angustifolium, Carex lasiocarpa, Drosera rotundifolia, Sphagnum magellanicum ) were all disappeared. The third period starts with the artificial flooding in 1994. In the beginning the peat-mosses were all extinct, floating mires appeared immediately and their quick succession started and still runs. The fourth period would be start with the appearance of peat-mosses.

Restricted access

In the microflora of sunflower seeds stored in domestic stores the, Alternaria species dominate, while those of Penicillium, Trichoderma, Stemphylium and Absidia spp. are present in lower numbers. During model tests (cca 20% seed moisture content, 25 °C, 4 weeks storage) the Alternaria species were almost completely eliminated and on the seeds mainly Aspergillus species, characteristic of stores, propagated. The moulds significantly deteriorated the quality of the seed and that of the produced oil and meal (reproductive ability, germinating power, oil content, lipoxygenase enzyme activity, acid value, peroxide value, fatty acid composition, UV absorbance, colour, sensorial properties, as well as the protein content, amino acid composition, colour and the smell of the meal), but no aflatoxin production occurred. The findings offer a comprehensive picture on the multiple destructive effects of incorrect storage.

Restricted access

Abstract  

A sample of 80 Hungarian scientists, authors or co-authors of a total number of 6273 papers—published between 1930–1976—has been analysed. Citation data to eachpaper were collected form the 1964–76 SCI's by manual search. Citation counts were distinguished with respect to the following categories: (I) the set of cited authors has element(s) common with the set of citing authors (self citation), (II) condition I is not satisfied, but the cited author under study and at least one of the citing authors were co-authors prior to the publication of the cited paper, (III) none of the former criteria is satisfied. The yearly average citation frequency of a paper was not corrected for obsolescence, since there is no evidence that the decay of citation frequency with time is independent of the absolute citedness of the paper. Individual performance has been measured (a) by the sum of the vearly average typeIII fractional citation frequencies over all of the author's papers, (b) by the sum of the yearly average citation frequency normalized to one single-authored paper per year over the period of the author's activity, (c) by the same as ina, but summed up only over the most highly cited papers scattering upwards from the individual's own average, (d) by the fractional authorship, and (e) by the number of items in the author's publication list. The first three parameters seem to be applicable in measuring the utility of the individual's scientific contribution with slightly different emphasis on different aspects. These parameters are uncorrelated with those measuring the output of individuals.

Restricted access
Authors: B. Nagy, J. Soós, B. Horvath, M. Kállay, B. Nyúl-Pühra and D. Nyitrai-Sárdy

During the ageing in barrels, the contact with the fine lees triggers several processes in wine. Lees has a reductive effect by absorbing dissolved oxygen and reducing the amount, which will remain in the wine. At present, minimizing the addition of sulphur dioxide is the trend in all viticultural areas. In this study, the effect of various sulphur dioxide levels was monitored in presence of the lees to determine which dose is appropriate to provide the protection of susceptible white wine against oxidation.

Without SO2 protection, the rH and redox potential changed slightly, so the level of dissolved oxygen seemed to be controlled during the ageing period by the lees, though the antioxidant effect of lees in itself was not appropriate to protect the polyphenol content from chemical oxidation, which led to considerable browning. With the addition of a lower amount of SO2 — 40 mg l2, the lees is already able to protect the white wine samples in all aspects.

Restricted access

Background and aims

Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common causes of end-stage renal disease (ESRD). The most important cause of death among ADPKD patients is cardiovascular (CV). The aim of this study was to examine the prognostic significance of arterial stiffness on CV and renal outcomes in ADPKD.

Methods

A total of 55 patients with ADPKD were examined. Pulse wave velocity was determined and stiffness index (SIDVP) was calculated. Combined primary endpoints (CV and renal) were major CV events (myocardial infarction, stroke, and CV intervention) as CV endpoints, and attaining of ESRD or start of renal replacement therapy as renal endpoints. Secondary endpoints were CV or renal endpoints separately.

Results

The mean age of those 55 ADPKD patients was 45 ± 12 years, 21 patients were male. The average value of the SIDVP was 11.11 ± 2.22 m/s. The patients were divided into two groups by the cutoff value of 11 m/s of SIDVP and then outcomes were analyzed. In the higher arterial stiffness group (SIDVP > 11 m/s), occurrence of combined primary endpoint (CV and renal) was significantly higher than in the group with more elastic arteries (p = 0.033). A statistically significant difference was found in the renal endpoints (p = 0.018), but not in the CV endpoints (p = 0.952) between the two groups.

Conclusions

Increased arterial stiffness predicts the onset of ESRD in ADPDK. Assessment of SIDVP appears to be a useful method for estimating the renal and CV prognosis in ADPKD.

Restricted access
Authors: Á. Tóth, E. Baka, Sz. Luzics, I. Bata-Vidács, I. Nagy, B. Bálint, R. Herczeg, F. Olasz, T. Wilk, T. Nagy, B. Kriszt, I. Nagy and J. Kukolya

Thermobifidas are thermophilic, aerobic, lignocellulose decomposing actinomycetes. The Thermobifida genus includes four species: T. fusca, T. alba, T. cellulosilytica, and T. halotolerans. T. fusca YX is the far best characterized strain of this taxon and several cellulases and hemicellulases have been cloned from it for industrial purposes targeting paper industry, biofuel, and feed applications. Unfortunately, sequence data of such enzymes are almost exclusively restricted to this single species; however, we demonstrated earlier by zymography that other T. alba and T. cellulosilytica strains encode the same enzyme sets. Recently, the advances in whole genome sequencing by the use of next generation genomics platforms accelerated the selection process of valuable hydrolases from uncharacterized bacterial species for cloning purposes. For this purpose T. cellulosilytica TB100T type strain was chosen for de novo genome sequencing. We have assembled the genome of T. cellulosilytica strain TB100T into 168 contigs and 19 scaffolds, with reference length of 4 327 869 bps, 3 589 putative coding sequences, 53 tRNAs, and 4 rRNAs. The analysis of the annotated genome revealed the existence of 27 putative hydrolases belonging to 14 different glycoside hydrolase (GH) families. The investigation of identified, cloned, and heterologously multiple cellulases, mannanases, xylanases, and amylases may result in industrial applications beside gaining useful basic research related information.

Open access
Authors: J. B.Nagy, J. N. Coleman, A. Fonseca, A. Destrée, Z. Mekhalif, N. Moreau, L. Vast and J. Delhalle

Organic polymers - carbon nanotubes nanocomposites are synthesized either by mechanical mixing of the two components or by covalently linking the nanotubes to the matrix. The various procedures will be overviewed and the determining factors will be identified for the best mechanical properties of the composites. On the other hand, it will be shown that for highest electrical conductivity much smaller amounts of carbon nanotubes are needed if the nanotubes can be aligned. The thermal conductivity of the nanocomposites will also be overviewed. Finally, together with nanoclay particles, nanotubes are inducing remarkable flame retardant properties in the nanocomposites materials.

Restricted access
Authors: Zs. Ürmös, M. K. Singh, B. Pálfalvy, D. Cserhalmi and J. Nagy
Restricted access

Glycine is a mandatory positive allosteric modulator of N-methyl-D-aspartate (NMDA)-type ionotropic glutamate receptors in the central nervous system. Elevation of glycine concentrations by inhibition of its reuptake in the vicinity of NMDA receptors may positively influence receptor functions as glycine B binding site on NR1 receptor subunit is not saturated in physiological conditions. Synaptic and extrasynaptic concentrations of glycine are regulated by its type-1 glycine transporter, which is primarily expressed in astroglial and glutamatergic cell membranes. Alteration of synaptic glycine levels may have importance in the treatment of various forms of endogenous psychosis characterized by hypofunctional NMDA receptors. Several lines of evidence indicate that impaired NMDA receptor-mediated glutamatergic neurotransmission is involved in development of the negative (and partly the positive) symptoms and the cognitive deficit in schizophrenia. Inhibitors of glycine transporter type-1 may represent a newly developed therapeutic intervention in treatment of this mental illness. We have synthesized a novel series of N-substituted sarcosines, analogues of the glycine transporter-1 inhibitor NFPS (N-[3-(4′-fluorophenyl)-3-(4′-phenylphenoxy)-propyl]sarcosine). Of the pyridazinone-containing compounds, SzV-1997 was found to be a potent glycine transporter-1 inhibitor in rat brain synaptosomes and it markedly increased extracellular glycine concentrations in conscious rat striatum. SzV-1997 did not exhibit toxic symptoms such as hyperlocomotion, restless movements, respiratory depression, and lethality, characteristic for NFPS. Besides pyridazinone-based, sarcosine-containing glycine transporter-1 inhibitors, a series of substrate-type amino acid inhibitors was investigated in order to obtain better insight into the ligand-binding characteristics of the substrate binding cavity of the transporter.

Restricted access
Authors: D. Vuono, C. C. Pavel, P. De Luca, J. B. Nagy and A. Nastro

Summary The ETS-10 is a newly formed titano-silicate the structure of which was resolved thanks to the XRD, EDS, HREM and mass NMR. The ETS-10 is a potentially good catalyst. The aim of this research is to study the physicochemical properties of ET(Zr)S-10 obtained from a gel containing different amounts of Zr. The analyses used are XRD, thermal analysis (TG-DSC), SEM, and 29Si NMR.

Restricted access