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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Analýza esterů kyseliny ftalové v zemědělských půdách ČR

Grossová, Lucie January 2019 (has links)
The thesis on the topic "The analysis of phthalic acid esters in agricultural soils in the Czech Republic" describes the properties of phthalic acid esters, the occurrence and the negative effects related to the environment and human health. The aim of this diploma thesis was to monitor phthalic acid esters, especially di-2- (ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) in agricultural soil samples. Monitoring of phthalates was carried out in cooperation with the Central Control and Testing Institute of Agriculture in Brno as part of their annual monitoring of phthalates and other organic contaminants in soils. During March 2018, a total of 40 soil samples were collected in 12 regions of the Czech republic. Before phthalate analysis, samples were extracted with a mixture of acetone-hexane (1:1). Using ultrasound was performed using high performance liquid chromatography with UV detection. Determined concentrations for DBP were from 0.13 to 1.07 mg.kg-1 dry weight and for DEHP from 0.13 to 1.02 mg.kg-1 dry weight.
202

Studium metabolického sydromu na myším modelu:úloha lipidů v potravě, tukové tkáně a AMP-aktivované proteinovékinázy / Study of metabolic syndrome in mice model: roles of dietary lipids, adipose tissue and AMP-activated protein kinase

Medříková, Daša January 2011 (has links)
Obesity and associated metabolic disorders, e. g. metabolic syndrome, represent a considerable health threat for modern society. Due to sedentary lifestyle, high caloric intake and changes in composition of diet, prevalence of obesity is increasing worldwide. One of the possible causes contributing to higher prevalence of obesity in recent population could be the change of fatty acids (FA) composition of dietary lipids, with the shift in the content of n-6 and n-3 FA toward n-6 FA. In contrast to n-6 FA, n-3 FA are known for their anti-atherogenic, anti-obesogenic and anti-inflammatory properties. In our experiments in mice, the capability of naturally occurred and chemically modified n- 3 long chain polyunsaturated fatty acids (LC-PUFA) in prevention and reversal of specific parts of metabolic syndrome was demonstrated. A specific chemical derivative of docosahexaenoic acid was proven to be very effective in preventing and improving metabolic conditions of animals exposed to high-fat (HF) diet challenge. Further, the involvement of AMP-activated protein kinase (AMPK), a master regulator of lipid metabolism, in skeletal muscle thermogenesis induced by HF-feeding was investigated. Activation of AMPK in the HF-fed mice is most possibly caused by increased leptin levels and represents an important link...
203

Vliv mastných kyselin na lipidový metabolismus a redukci tělesné hmotnosti / Effect of fatty acids on lipid metabolism and weight reduction

Hlavatý, Petr January 2011 (has links)
Fat tissue plays a main role in the development of the metabolic syndrome. Many components of the metabolic syndrome may be improved by dietary arrangements, including an increased intake of n-3 PUFA. In addition to the positive effect of n-3 PUFA, a possible effect of a higher calcium intake on influencing weight loss and energy metabolism has also been discussed for a long time. In addition to nutritional factors, genetic factors significantly contribute to influencing weight and lipid and glucose metabolism. In study A, 40 obese women were observed during three weeks of weight reduction management. Women were randomly divided into two groups. The first group received yogurt enriched with n-3 PUFA, and the second group consumed yoghurt without the supplementation. The results show that low-dose supplementation with n-3 PUFA in yogurt in combination with a reduced energy intake increases n-3 PUFA content in serum lipids and prevents adverse changes in the composition of FA in serum after a short-term low-calorie diet. In study B, we monitored the influence of n-3 PUFA supplementation on short-term weight management with VLCD in 20 women with severe obesity, who were randomly divided into two groups. The first group received VLCD enriched with n-3 PUFA, the second group VLCD with a placebo. The addition of...
204

Studium metabolického sydromu na myším modelu:úloha lipidů v potravě, tukové tkáně a AMP-aktivované proteinovékinázy / Study of metabolic syndrome in mice model: roles of dietary lipids, adipose tissue and AMP-activated protein kinase

Medříková, Daša January 2011 (has links)
Obesity and associated metabolic disorders, e. g. metabolic syndrome, represent a considerable health threat for modern society. Due to sedentary lifestyle, high caloric intake and changes in composition of diet, prevalence of obesity is increasing worldwide. One of the possible causes contributing to higher prevalence of obesity in recent population could be the change of fatty acids (FA) composition of dietary lipids, with the shift in the content of n-6 and n-3 FA toward n-6 FA. In contrast to n-6 FA, n-3 FA are known for their anti-atherogenic, anti-obesogenic and anti-inflammatory properties. In our experiments in mice, the capability of naturally occurred and chemically modified n- 3 long chain polyunsaturated fatty acids (LC-PUFA) in prevention and reversal of specific parts of metabolic syndrome was demonstrated. A specific chemical derivative of docosahexaenoic acid was proven to be very effective in preventing and improving metabolic conditions of animals exposed to high-fat (HF) diet challenge. Further, the involvement of AMP-activated protein kinase (AMPK), a master regulator of lipid metabolism, in skeletal muscle thermogenesis induced by HF-feeding was investigated. Activation of AMPK in the HF-fed mice is most possibly caused by increased leptin levels and represents an important link...
205

Studium biomolekulárních interakcí pomocí optických biosenzorů s povrchovými plasmony / Study of Biomolecular Interactions with Surface Plasmon Resonance Biosensors

Šípová, Hana January 2014 (has links)
Surface plasmon resonance (SPR) biosensors represent one of the most advanced sensing technologies for real-time studies of biomolecular interactions. In this thesis, methods for functionalization of SPR substrates were optimized and studied via spectroscopic methods. Effects related to the SPR sensor microfluidic interface on the measured biomolecular interactions were analyzed, and furthermore, means to decrease mass-transport limitations were proposed. Several SPR-based assays regarding the detection of nucleic acids were developed, which allow for the detection of physiologically relevant concentrations of nucleic acids as well as point mutations in a nucleic acid sequence. Assays for the determination of the enzymatic activity of HIV integrase and ribonuclease H were developed. These assays can be employed for the design and synthesis of molecules that function either as antiviral drugs or as gene-regulating agents.
206

Studium struktury a interakcí nukleových kyselin pomocí rezonančního Ramanova rozptylu / Study of nucleic-acid structure and interactions by resonance Raman scattering

Klener, Jakub January 2021 (has links)
Despite the decades of intensive research, nucleic acids represent still a permanent object of structural studies. Within the framework of the doctoral work, the apparatus for measurement of UV excited resonance Raman spectra (UV RRS) was built up and optimized. A realistic and complex interpretation table was prepared based on analysis of published data and extensive series of UV RRS measurements on NA model structures, mononucleotides, and polynucleotides. The established methodology was verified when applied in several structural studies of nucleic acids, mainly the study of the influence of magnesium ions on the equilibrium between duplexes and triplexes formed by PolyA and PolyU homopolynucleotides, a study of temperature-induced structural changes in DNA double helix and DNA hairpin, and investigation of slow structural transitions of guanine quadruplexes induced by the presence of potassium ions. The results of the test measurements and the above-mentioned studies have shown that the created methodology for studying UV RRS of nucleic acids brings most of the expected benefits of the resonance excitation: the possibility of Raman scattering measurements at the same concentrations as in the case of UV absorption, high sensitivity to fine temperature-induced structural changes and good interpretability...
207

Studium reaktivity biopolymerů v gelové fázi / Reactivity-mapping studies on biopolymers in hydrogel forms

Smilek, Jiří January 2012 (has links)
The diploma thesis is focused on the study of interactions between biopolymers and model probes in a hydrogel media utilizing diffusion processes. The main aim was to test and to optimize selected combination of diffusion methods (diffusion cells and unsteady diffusion) in study of interactions between biopolymers and organic dyes. Anionic (humic acids) and cationic (chitosan) representatives of biopolymers were utilized and methylene blue and methylene orange were used as a reactivity probe in the case of humic acids and chitosan, respectively. Another appreciable part of the work is represented by in-depth characterization of applied biopolymers and hydrogel samples by a wide range of analytical and physico-chemical methods (rheometry, UV-VIS, FT-IR etc.). Besides particular experimental results on studied systems, the diploma thesis provides both theoretical and practical background for subsequent applications of the innovative and full-automated method for reactivity mapping of biopolymers.
208

Nové přístupy k ochraně srdce před postischemickým selháním / Novel Approaches To Protect The Heart Against Postischemic Failure

Hrdlička, Jaroslav January 2021 (has links)
Ischemic heart disease and resulting heart failure (HF) belong to the leading causes of death in developed countries. In order to prevent HF and improve clinical outcome in patients with myocardial infarction, novel therapies are required to protect the heart against the detrimental effect of ischemic injury. Due to the failure to translate numerous available experimental cardioprotective strategies into clinical practice, the need for novel protective treatments persists. We have, therefore, tried to apply a novel approach to cardiac protection against the postischemic HF induced in rats by ligation of the coronary artery. For this purpose, we have studied (i) the preventive and therapeutic effects of adaptation to continuous normobaric hypoxia (CNH; 12% O2) and exercise training (ExT; treadmill running), and (ii) the possible cardioprotective potential of epoxyeicosatrienoic acid (EET)-based therapy in order to attenuate the postischemic HF in rats. Adaptation to CNH and ExT is known for their cardioprotection in acute ischemia/reperfusion (I/R) injury manifested as reduction of infarct size. EETs exert antihypertensive effects and thus seem to be perspective for the research in clinically relevant models of cardioprotection in hypertensive animals. Our results have revealed that: - CNH prior to...
209

Analýza reologických vlastností rostlinných olejů a jejich složek / Analysis of the rheological properties of vegetable oils and their components

Divílek, Petr January 2014 (has links)
This Master’s thesis is dealing with theoretical analysis of vegetable, mineral oils and synthetic fluids, and with measuring of density and viscosity of selected samples of electric insulating fluids. The main part of the thesis is focused on vegetable oils and their elements called fatty acids. Those are more detail described in separate capitols. In those capitols is described their utilization in engineering practice with focus on energetics, where vegetable oils are used in larger scale. In experimental part of the work is measurement of density and dynamic viscosity. Viscosity was measured on two different machines, first the Hoppler viscometer and on vibrating viscometer. Results of these measurement are evaluated in tables and graphs.
210

Vztah n-3 polynenasycených mastných kyselin a buněčných senzorů energetického stavu AMPK a SIRT1 / Relation between n-3 polyunsaturated fatty acids and cellular sensors of energetic state

Zouhar, Petr January 2010 (has links)
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.

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