Background: Aminothiols have been implicated in the pathogenesis of arteriosclerosis, and reliable methods are needed to determine their concentrations in body fluids. We present a comparison of two analytical methods and focus on the reduction of low-molecular weight and protein-mixed disulfides of homocysteine, cysteine, cysteinyl-glycine, and glutathione. Methods: The plasma total aminothiol profile was determined by HPLC with fluorescence detection after derivatization with ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate. Disulfides and protein-bound aminothiols were reduced by either tri-n-butylphosphine (the TBP method) or tris(2-carboxyethyl)phosphine (the TCEP method); the effects of temperature, time of reduction, and concentration of reductants were evaluated. Results: The intraassay imprecision (CV) was <3% for all aminothiols using both methods. The interassay CVs for total cysteine (tCys), total cysteinyl-glycine (tCys-Gly), and total homocysteine (tHcy) were <4% and <8% for the TCEP and TBP methods, respectively, whereas for total glutathione (tGSH) the interassay CV was >12% for both methods. Deming regression and Bland–Altman difference plots showed positive biases for total aminothiol concentrations determined by the TCEP method relative to the TBP method. The mean proportional biases were 65%, 27%, 6%, and 60% for tCys, tCys-Gly, tHcy, and tGSH, respectively. The calculated concentrations of total aminothiols by the TCEP method were less influenced by changes in temperature and concentration of reducing agent or by calibrator matrix. Conclusions: The agreement between the TCEP and TBP methods was considerably lower for the determination of tCys, tCys-Gly, and tGSH than for tHcy. For total-aminothiol determination, the TCEP method yields better reproducibility and is more robust than the TBP method.

The article provides assessment of the significance of the e-learning implementation, as one of the most modern methods of teaching, using information technology in security education. The implementation is based on the main idea of e-learning, it means, that it is necessary to provide free and unrestricted access for students towards their education. If we want the society to take advantage of security education as an intensive factor of economic and social growth, it is important to know the manner of applying such methods, forms and means, the intensity and the circumstances necessary to impact on the learners, in order to achieve the final efficiency of education.

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. He was a Fellow of the IEEE and the Institution of Engineering and Technology. His research interests include mechatronic systems, intelligent robotic systems, dust mass concentration measurement and measurement of non-electric quantities. He has authored more than 150 journal and conference papers on these topics. Ing. Ivan Virgala received M.Sc. degree in mechatronics from Technical University of Košice. He was born in 1983. He is currently working toward the Ph.D. degree in mechatronics at Technical University of Košice, Slovakia. Her research interests include mechatronics systems and robotics. He has authored 7 journal and conference papers on these topics. Ing. Martina Vacková received M.Sc. degree in mechatronics from Technical University of Košice. She was born in 1985. She is currently working toward the Ph.D. degree in mechatronics at Technical University of Košice, Slovakia. Her research interests include mechatronics systems and robotics. She has authored 7 journal and conference papers on these topics. KEY WORDSSnake, Locomotion, Rectilinear, Two-Mass System ABSTRACT A few previous decades the researchers and the designers started to copy the animal motion to the mechanisms. The principal motivations of the snaky locomotion are the environments where the traditional machines are not applicable due their dimensions or shapes and where the accessories like the wheels or the legs fail. The paper deals with the dynamic analysis of the two-mass system imitating the snake rectilinear motion on the level surface. Within the research there were made various modifications of the system and through the simulation was verified the behavior of the kinematic parameters. Based on the mentioned displacements and the speeds depending on Acta Mechanica SlovacaJournal published by Faculty of Mechanical Engineering -Technical University of Košice 75 the time it is possible to determine the optimal parameters of examined dynamic system.

Article deals with the security education in the conditions of universities, the implementation of innovative trends into this process due to increasing its effectivity. When solving the problems in the area of security, the important aspect is education and professional training of the employees of security services, but also workers and managers at different levels in the area of security, where high knowledge demands are required. In the context of education at universities, security awareness of people coming from schools to work may help to increase better conditions in this area. Deepening their knowledge and skills connected with the security, increasing qualification and training of graduates, preparation for solving crisis and emergency phenomena in different areas of security (civil, economic, environmental, technical and technological, logistical, and etc.) may also help to increase better conditions in this area. If we use security education as intensive factors of economic, social growth of the companies to, it is important to know how such methods, forms and means in which the intensity and under what circumstances it is necessary to work on learning to achieve effectiveness of the resulting learning.