National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Regulation of lipolysis and re-esterification in white adipose tissue - possible role of FGF21
Špiláková, Blanka ; Zouhar, Petr (advisor) ; Šilhavý, Jan (referee)
Fibroblast growth factor 21 (FGF21) is a unique peptide hormone involved in the energy homeosta- sis, as well as in the regulation of glucose and lipid metabolism. Numerous animal studies suggest that FGF21 may be used as a potential treatment for obesity and type 2 diabetes mellitus. It was found out, that FGF21 counteracts the development of obesity presumably by increasing energy expenditure through activation of thermogenesis in brown and white adipose tissue. FGF21 apparently also inhibits lipolysis. However, the specific mechanism of action of FGF21 is not clear. In our experiments we studied the antiobesogenic effects of FGF21 on mice model of diet-induced obesity at thermoneutrality. It is assumed that this model approach (in contrast to housing mice at standard laboratory temperature) mimics closely the metabolic status of humans. During the 4- to 8-day FGF21 treatment we observed a gradual reduction of lipid content in the brown and white adipose tissue and liver, especially in combination with β3-adrenergic stimulation. We have confirmed that FGF21 inhib- its lipolysis and also stimulates browning in certain adipose tissue depots. Furthermore, we have found that the effect of FGF21 on fatty acid secretion by adipose tissue is not mediated by changes in the fatty acid re-esterification...
Importance of adipose tissue metabolism for whole-body energy balance
Zouhar, Petr ; Flachs, Pavel (advisor) ; Rossmeislová, Lenka (referee) ; Kazdová, Ludmila (referee)
Adipose tissue plays a crucial role in nutrient and energy homeostasis. At the time of worldwide pandemy of obesity and consequent metabolic syndrome, a great effort is made to find new treatments with potential to preserve insulin sensitivity, or even counteract development of obesity and type 2 diabetes. There are three principal possibilities how the adipose tissue biology can contribute to this goal: 1) induction of UCP1-dependent energy dissipation in brown adipose tissue; 2) conversion of white adipose depots to brown-like tissue (i.e. "browning"); and 3) stimulation of UCP1-independent thermogenesis in white adipose tissue. This thesis is based on two published works and one article under preparation. Generaly, it is focused on three different approaches targeting the above mentioned processes in adipose tissue of laboratory mouse: 1) diet supplementation with bile acids; 2) combination treatment of ω-3 polyunsaturated fatty acids and calorie restriction; and 3) cold exposure. In the experiments with administration of bile (specifically chenodeoxycholic) acid to mice, we confirm specific induction of UCP1 in both brown and subcutaneous white adipose tissue, as well as reversion of obesity in the response to the treatment. Nevertheless, most of the acute beneficial effects are mediated by...
The relation between n-3 polyunsaturated fatty acids and cellular sensors of energetic state AMPK and SIRT1
Zouhar, Petr ; Kalous, Martin (referee)
Relation between n-3 polyunsaturated fatty acids and cellular sensors of energetic state Petr Zouhar Abstract The regulatory proteins, which are able to react to energetic state of the cell by feed-back mechanism, are important factors in regulation of metabolic processes. Big attention is focused on the AMP activated kinase (AMPK) and the NAD+ activated deacetylase SIRT1. These enzymes interact together and their stimulation increases mitochondrial biogenesis and fatty acid oxidation. Due to this fact they function beneficially against the onset of obesity, insulin resistance and ageing. Fasting, exercise and some antidiabetogenic drugs act through these regulators. n-3 polyunsaturated fatty acids (PUFA) are also believed to be beneficial because of their stimulative effects on mitochondrial biogenesis and β-oxidation. Our previous work has showed that intake of higher doses of n-3 polyunsaturated fatty acids (PUFA) in diet leads to increase of AMPK activity in white adipose tissue. New results presented in this thesis show that SIRT1 is essential for increase of β-oxidation stimulators (PPARα etc) expression in response to n-3 PUFA in diet. n-3 PUFA also improve the metabolic profile synergistically in combination with calorie restriction. It occurs probably through the activation of SIRT1/AMPK/PGC-1α...
Relation between n-3 polyunsaturated fatty acids and cellular sensors of energetic state
Zouhar, Petr ; Pecina, Petr (referee) ; Flachs, Pavel (advisor)
The important factor in regulation of metabolic processes is regulatory proteins, which are able to react by feed-back to energetic state of the cell. Big attention is focused on the AMP activated kinase (AMPK) and NAD+ activated deacetylase SIRT1. These enzymes interact together and their stimulation increases mitochondrial biogenesis and fatty acid oxidation. Due to this it functions beneficially against the onset of obesity, insulin resistance and ageing. Fasting, exercise and some antidiabetogenic drugs act by these regulators. n-3 polyunsaturated fatty acids (PUFA) are also known because of their stimulative effects on mitochondrial biogenesis and -oxidation. Previous work of our group have showed that intake of higher dose of n-3 polyunsaturated fatty acids (PUFA) in diet lead to increase in activity of AMPK in white adipose tissue. New results presented in this thesis show that SIRT1 is essential for increase in expression of stimulators of -oxidation (PPAR etc) in response to n-3 PUFA in diet. n-3 PUFA futher improve the metabolic profile synergistically with calorie restriction probably through SIRT1.
Evaluation of the Financial Situation in the Firm and Proposals to its Improvement
Zapletalová, Gabriela ; Zouhar, Petr (referee) ; Karas, Michal (advisor)
The bachelor thesis is focused on the assessment of the financial situation of the selected company through financial analysis methods. For this purpose was chosen company EKO-SYSTÉM, s.r.o. Based on the results of financial analysis are set out proposals and actions that could improve financial situation of the company.
Fatigue crack front shape estimation
Zouhar, Petr ; Klusák, Jan (referee) ; Hutař, Pavel (advisor)
The presented master’s thesis deals with fatigue crack front shape estimation. The aim of this thesis is to create an iterative process leading to the real fatigue crack front shape. Thesis is solved using finite element method. The work is divided into two logical parts. The first part of the thesis describes the basic concepts of linear elastic fracture mechanic (LEFM), methods used for estimation of stress intensity factor and stress singularity exponent. The first part further describes some phenomenon’s accompanying the mechanism of fatigue crack growth as for example crack tip curving and crack closure. In the second part of the thesis there is studied an affect of the free surface on the fracture parameters, especially the affected distance from the free surface is determined. Based on the assumption of a constant stress intensity factor and stress singularity exponent along the crack front, an iterative process leading to fatigue crack front shape is presented. The accuracy of the result is discussed by comparing of obtained crack front shapes with experimental data at the end of the thesis.
Systems for checing electronic texts
Zouhar, Petr ; Malý, Jan (referee) ; Pfeifer, Václav (advisor)
The work deals with the possibility of control of electronic texts. Whether it is a source codes or standard text documents. The first chapter is devoted to a brief explanation of the term plagiarism and its characters. Sequentially we describe the methods and metrics used to detect plagiarist. Then we pay attention to detect plagiarism in the free text and source codes. We describe the way of preprocessing of a file and choice of basic units, which represent the document in the comparing. Source codes have a exact syntax. Therefore we attend to the syntax and semantic analysis in the chapter, which describes the check of source codes. The second half of the work is focused on the practical part, particularly on programs intended to control the source codes. The programs are divided to the freely available and the commercial. This is followed by their brief description and if it is a free trial possible we mention the results from this comparing. So we created a corpus of source codes. At the end of the work we focus on design of a program, which compares two source codes on the basis of statistical similarities.
Random number generator
Zouhar, Petr ; Martinásek, Zdeněk (referee) ; Sobotka, Jiří (advisor)
The thesis deals with issues of random numbers, their generating and use in cryptography. Introduction of work is aimed to resolution of random number generators and pseudo--random number generators. There is also included often used dividing generators on software and hardware. We mention advantages and disadvantages of each type and area of their use. Then we describe examples of random and pseudorandom numbers, mainly hardware based on physical phenomenon such as the decay of radioactive material or use atmospheric noise. The following part is devoted to suggestion own random number generator and a description of its functionality. In the second half of the work we devote to the field of cryptography. We know basic types of cryptographic systems, namely symmetric and asymmetric cryptosystems. We introduce a typical representant the various type and their properties. At the end of the work we again return to our random number generator and verify the randomness generated numbers and obtained cryptograms.
Possibilities of estimation of selected fracture parameters under conditions of LEFM
Zouhar, Petr ; Hutař, Pavel (referee) ; Ševčík, Martin (advisor)
The presented bachelor´s thesis deals with possibilities of estimation of selected fracture parameters under conditions of linear elastic fracture mechanic (LEFM). The aim of this thesis is to quantify the accuracy of specific methods for the estimation of fracture parameters from a known stress and strain field obtained using numerical methods. Thesis is solved using finite element method. The work is divided into two logical parts. The first part of the thesis describes the basic concepts of LEFM and selected methods used for estimation of fracture parameters, namely the stress intensity factor, strain energy release rate and J-integral. A detailed description of the numerical model, a sensitivity analysis of the FEM mesh density and obtained results are described in the second part, focused on the solution of the problem,. The accuracy of each method is expressed by comparing with a known reference value of stress intensity factor. The applicability of selected methods for estimation of the stress intensity factor is shown on a practical example of three-dimensional body containing a crack.

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