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Martin Lukac

Abstract

Biodiversity not only responds to environmental change, but has been shown to be one of the key drivers of ecosystem function and service delivery. Forest soil biodiversity is also governed by these principles, the structure of soil biological communities is clearly determined by spatial, temporal and hierarchical factors. Global environmental change, together with land-use change and forest ecosystem management, impacts the aboveground structure and composition of European forests. Due to the close link between the above- and belowground parts of forest ecosystems, we know that soil biodiversity is also impacted. However, very little is known about the nature of these impacts; effects they have on the overall level of biodiversity, the functions it fulfills, and on the future stability of forests and forest soils. Even though much remains to be learned about the relationships between soil biodiversity and forest ecosystem functionality, it is clear that better effort needs to be made to preserve existing soil biodiversity and forest conservation strategies taking soils into account must be considered.

Open access

E. Lukács and M. Polóni

Tuning Mazda B6 Engine for Sports Competitions

Improving output parameters of the Mazda B6 combustion engine from the vehicle Mazda 323 for amateur "hill climb" and "rally" competitions has been analysed. Tuning of such an engine for sport competitions means the optimisation of its parameters at the lowest possible economic costs, within the revolution range 4000 - 6000 min-1, where the engine during competition works most often. With the help of the program Lotus Engine Simulations, the construction of the exhaust manifold has been optimised, together with valve timing and other adjustments, listed in the work, on output parameters of the engine. The optimum combinations of parameters were experimentally verified on a chassis dynamometer. Final adaptations have led within the previously specified range of revolutions to an improvement between 5 and 22% in power and torque.

Open access

M. Lukáč, I. Prokipčák, I. Lacko and F. Devínsky

Abstract

The solubilisation of natural compound, (+)-usnic acid, in micellar solutions of gemini (N,N’-didecyl-N,N,N’,N’-tetramethylethane-1,2-diyldiammonium dibromide) and heterogemini (decyl 2-[decyl(dimethyl)ammonio]ethylphosphate) surfactants and their equimolar mixture has been studied. The highest solubility was found for gemini surfactant. The relationship between synergism in surface properties of mixture of surfactants and their solubilisation properties is also discussed.

Open access

M Vazan, I Kasubova, A Vanochova, P Lukac, L Plank and Z Lasabova

Abstract

Introduction: A clonal population of B-cells is defined as those cells arising from the mitotic division of a single somatic cell with the same rearrangement of immunoglobulin genes. This gives rise to DNA markers for each individual lymphoid cell and its progenies and enables us to study clonality in different B-cell malignancies using multiplex polymerase chain reaction - PCR. The BIOMED-2 protocol has been implemented for clonality detection in lymphoproliferative diseases and exploits multiplex PCR reaction, subsequently analyzed by heteroduplex analysis (HDA) using polyacrylamide gel electrophoresis (PAGE). With the advent of miniaturization and automation of molecular biology methods, lab-on-chip technologies were developed and replace partially the conventional approaches. We tested device for microfluidic chip, which is used for B-cells clonality analysis, using a PCR reaction for three subregions called frameworks (FR) of the immunoglobulin heavy locus (IGH) gene.

Material and Methods: For the implementation and comparison of the two methods we analyzed three unknown B-cell chronic lymphocytic leukemia (B-CLL) samples. As positive control (PK) we used one formalin-fixed, paraffin-embedded (FFPE) sample from B-CLL lymph node. The DNA was extracted from FFPE sections and multiplex PCR was used to amplify IGH gene segments. After PCR, the HDA was performed, the DNA fragments were evaluated on the PAGE and the microfluidic chip electrophoresis as well, and the results were compared.

Results: Using HDA with subsequent PAGE, we were able to confirm the clonality of the positive control and the tested samples. The same results were obtained by the Bioanalyzer 2100. The microfluidic chip electrophoresis was persuasive in all tested samples.

Conclusion: The implementation of microfluidic chip electrophoresis for detection of B-cell clonality by BIOMED-2 protocol on the device Agilent 2100 Bioanalyzer was successful and yielded the same results as the HDA - PAGE. Moreover, chip electrophoresis system is faster for preparation and less laborious than the conventional HDA - PAGE method.