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Nanopages
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.

Open access
Nanopages
Authors:
A. Szabo
,
A. Fonseca
,
L. P. Biro
,
Z. Konya
,
I. Kiricsi
,
A. Volodin
,
C. Van Hasendonck
, and
J. B.Nagy

Some recent results on the synthesis of coiled carbon nanotubes (CNTs) are summarized. Several supported catalysts can lead to the formation of coiled CNTs. Interestingly, certain domains of the coil pitch and coil diameter are favoured, and two “stability islands”are found in the 3D representation of the number of coiled CNTs as a function of both coil pitch and coil diameter. It is emphasized that these nanotubes are formed either by introducing pairs of five-membered ring - seven-membered ring or by forming haeckelite structures. The coiled CNTs could be used in nanocomposite reinforcement as well as special sensors based on their remarkable mechanical and electrical properties.

Open access
Interventional Medicine and Applied Science
Authors:
K. Szakszon
,
Z. L. Veres
,
M. Boros
,
S. Sz. Kiss
,
B. Nagy
,
E. Bálega
,
á. Papp
,
E. Németh
,
I. Pataki
, and
T. Szabó

Abstract

We report a case of an infant with spontaneous chylothorax due to the congenital malformation of a small lymph vessel of the chest wall. Conservative therapy with omitting long-chain fatty acids from the diet, fat-free nutrition, total parenteral nutrition and intravenous somatostatin did not result in the decrease of pleural effusion. Thoracic surgical intervention performing thoracic duct ligation and using fibrin sealants was applied after 10 days of unsuccessful conservative therapy, and resulted in the complete recovery of the patient. Our experience support the already existing observations, that in cases where the daily loss of chyle exceeds 100 ml per age years and/or lasts longer than 2 weeks, early surgical intervention is recommended.

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Abstract

Purpose

Intensive exercise significantly lowers the pH of muscle and blood; beta-alanine supplementation can increase carnosine levels, the absence of which leads to an early acidosis and fatigue. The aim of our work is to investigate the effect of a single dose of beta-alanine supplementation on well-trained rowing athletes.

Materials/Methods

The spiroergometric parameters of the participants (n = 28) were examined a total of four times (T1,T2,T3,T4). After measurement (T3), participants received a beta-alanine supplementation at a dose of 50 mg/kg−1 body weight. We compared the results of the four measurements as well as the blood lactate values obtained from the fingertip before and after the tests.

Results

The different load physiological parameters and the lactate values measured after the tests did not show any significant difference. The mean lactate value prior to test (T4) was 1.8 (mmol*L−1), which is significantly higher than the mean-value of the two previous studies: T1 = 1.6 (mmol*L−1); (P = 0.00), T3 = 1.55 (mmol*L−1); (P = 0.04).

Conclusions

The higher lactate value measured before test (T4) was probably due to the longer time to return to the baseline values after the series load. In conclusion, a single dose of beta-alanine supplementation has no effect on performance. In order to elicit the ergogenic effect of beta-alanine, the use of short, intermittent diet therapy intervention is not recommended.

Open access
Acta Alimentaria
Authors:
E. Horvath-Szanics
,
J. Perjéssy
,
A. Klupács
,
K. Takács
,
A. Nagy
,
E. Koppány-Szabó
,
F. Hegyi
,
E. Németh-Szerdahelyi
,
M.Y. Du
,
Z.R. Wang
,
J.Q. Kan
, and
Zs. Zalán

The increasing consumer demand for less processed and more natural food products – while improving those products’ quality, safety, and shelf-life – has raised the necessity of chemical preservative replacement. Biopreservation refers to extended storage life and enhanced safety of foods using the natural microflora and (or) their antibacterial products. Chitinolytic enzymes are of biotechnological interest, since their substrate, chitin, is a major structural component of the cell wall of fungi, which are the main cause of the spoilage of food and raw plant material. Among the several organisms, many bacteria produce chitinolytic enzymes, however, this behaviour is not general. The chitinase activity of the lactic acid bacteria is scarcely known and studied.

The aim of the present study was to select Lactobacillus strains that have genes encoding chitinase, furthermore, to detect expressed enzymes and to characterise their chitinase activity. Taking into consideration the importance of chitin-bindig proteins (CBPs) in the chitinase activity, CBPs were also examined. Five Lactobacillus strains out of 43 strains from 12 different species were selected by their chitinase coding gene. The presence of the chitinase and chitin-biding protein production were confirmed, however, no chitinolytic activity has been identified.

Open access
Acta Botanica Hungarica
Authors:
Cs. Molnár
,
Zs. Molnár
,
Z. Barina
,
N. Bauer
,
M. Biró
,
L. Bodonczi
,
A. Csathó
,
J. Csiky
,
J. Deák
,
G. Fekete
,
K. Harmos
,
A. Horváth
,
I. Isépy
,
M. Juhász
,
J. Kállayné Szerényi
,
G. Király
,
G. Magos
,
A. Máté
,
A. Mesterházy
,
A. Molnár
,
J. Nagy
,
M. Óvári
,
D. Purger
,
D. Schmidt
,
G. Sramkó
,
V. Szénási
,
F. Szmorad
,
Gy. Szollát
,
T. Tóth
,
T. Vidra
, and
V. Virók

The first version of the map of the Hungarian vegetation-based landscape regions were prepared at the scale of 1: 200,000 (1 km or higher resolution). The primary goal of the map was to provide an exact background for the presentation and evaluation of the data of the MÉTA database. Secondly, we intended to give an up-to-date and detailed vegetation-based division of Hungary with a comprehensive nomenclature of the regions. Regions were primarily defined on the basis of their present zonal vegetation, or their dominant extrazonal or edaphic vegetation. Where this was not possible, abiotic factors that influence the potential vegetation, the flora were taken into consideration, thus, political and economical factors were ignored. All region borders were defined by local expert botanists, mainly based on their field knowledge. The map differs in many features from the currently used, country-wide, flora-or geography-based divisions in many features. We consider our map to be temporary (i.e. a work map), and we plan to refine and improve it after 5 years of testing.

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