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UV-photochemical generation of volatile selenium compounds for ultratrace analysis by AAS
Rybínová, Marcela
This thesis deals with the study of UV-photochemical generation of volatile compounds (UV-PVG) in connection with atomic absorption spectrometry (AAS). Selenium (Se(IV)) was selected as a model analyte and many experiments were carried out to expand the current sum of knowledge of the topic. The study was commenced by assembling the UV-PVG apparatus in the continuous flow mode. The detection method used was AAS with externally heated quartz furnace atomizer. The focus of the first step of the study was on the construction of the volatile compounds generator (UV-photoreactor) with emphasis on the material used; tubes made of teflon or quartz of different diameters were tested. The construction of the apparatus was followed by optimization of the reaction conditions (the type and concentration of the photochemical agent and other agents, which increase the analytical signal; the carrier gas and the auxiliary hydrogen gas flow rate; the sample flow rate). Eventually, the analytical figures of merit of the selenium determination using the proposed method were found. The results showed that teflon reaction tubes are a good competitor to those made of quartz. The accuracy of the method has been successfully verified by analysis of certified reference material and its applicability has been further tested...
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Use of Nutrition Supplements for the Elderly
Tenglerová, Dana ; Kulhavá, Miluše (advisor) ; Podaná, Jana (referee)
The primary goal of my thesis was to describe the use of food supplements by seniors. Most seniors use medications prescribed by physicians and some of them also use over-the-counter food supplements that are more easily accessible. Seniors, in particular, are susceptible to considering food supplements to be as efficient as medications under the incessant influence of massive advertising on TV and other media, and many of them are willing to spend considerable amounts from their income on such preparations. In the theoretical part of my thesis, I define the term 'senior', describe the traits of ageing, and focus on the topic of nutrition in this age group. Then I focus on food supplements in general and their distinction from medications. The end of the theoretical part is focused on advertising and its impact on seniors. In the research part, which was prepared by means of a quantitative research, I examine the use of food supplements among seniors aged over 65, hospitalised at the Slaný Hospital. A total of 100 respondents were addressed, and 95 questionnaires were used at the end. The research shows that 60 % of the respondents use food supplements regularly or occasionally. One of the sub-goals of the thesis was determining the financial burden for seniors in purchasing the preparations....
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Safety of selected dietary supplements with regard to the content of food additives I.
Rohlíková, Martina ; Pokladníková, Jitka (advisor) ; Marešová, Helena (referee)
Safety of the selected food supplements in terms of the presence of additives Additives are commonly present not only in food, but also in food supplements. Safety of these substances remains a question. The aim of the theses is to evaluate the safety of the best selling supplements in the Czech Republic in the year 2011 from the viewpoint of additives and constituents. Given the scale of researched products, I focused on products strengthening the cardiovascular system containing omega 3 fatty acids , garlic, coenzyme Q 10 and lecithin. As a source of information about the content and the presence of additives, the data from the Ministry of Health and the Information System decision of the Chief Hygienist (IS RoHy) were used. The safety evaluation of additives was carried out on the basis of the available methodology for consumers. Information about adverse effects of additives and content substances were searched using information databases Martindale , Reprotox, AltMedDex, Drugdex, National Center for Complementary and Alternative Medicine (NCCAM), IPCS INCHEM, PubMed independent commission database JECFA Joint FAO / WHO Expert committee on Food additives. Descriptive statistics was used. Of the large number of products (97), 5 products were classified as safe and 92 as products harmful to...
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Nutritional strategy for long-distance cross-country skiers
Opočenská, Tereza ; Česák, Petr (advisor) ; Šimková, Michaela (referee)
Title: Nutritional strategy for long-distance cross-country skiers Objectives: The aim of the bachelor thesis is to answer as the clearest as possible the following research questions: 1. How appropriate diet affects the internal environment of the body long-distance cross-country skiers? 2. What composition of the diet and supplements is most suitable for long-distance cross-country skiers? 3. When to start eating regime that will help competitors prepare the body for the completion of remote cross-country skiing? Methods: We used the research of czech and foreign literature. We searched the scientific studies related to our theme through the service Google Scholar. We also drew from licensed Internet databases (PubMed, SPORTDiscus, Scopus, ProQuest, OvidSP, JSTOR). Results: We found that long-distance cross-country skiers should follow the macronutrients and micronutrients content in connection with food intake. The ratios of nutrients taken depends on whether it is a period before the race, during the race or after its completion. However, a key role in all three phases perform carbohydrates. Optimal nutrition strategy should start no later than 1-3 days before the race. Keywords: sport, exercise, cross-country skiing, nutrition, food supplements, endurance, performance
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Food supplements and nutrition of performance and professional cyclists
Bednář, Michal ; Šafránek, Jiří (advisor) ; Polášková, Marcela (referee)
Title of the thesis: Food supplements and nutrition and performance of professional cyclists The goal of the paper: The aim of my work is to determine differences in the useing of dietary supplements and performance by professional cyclists. I also find out how different are the twosupplementation groups monitored before, during and after exercise. I focused on it also which marks of supplements by professional cyclist and cyclist who prefer performance. Of course I did not neglect to compare the groups surveyed drinks. Methodology: The data I obtained through a questionnaire that I circulated by an e-mail over the Internet.With some athletes I regularly meet in person, that I used for directly answering a questionnaire. The questionnaire used was clear and simple questions. The questionnaire is given below in the Annex. Most of the respondents interviewed were male and the age range was wide. Results: The results show that the greatest differences between groups of respondents are insupplementation before, during and after exercise. Differences are also in used the labeling of dietary suplements. Professional cyclists gather information about supplements from sources other than performance cyclists. Professional cyclists are mostly used by councils traper or learn from the experience of thein team...
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Introducing of method of pyridoxine determination by liquid chromatography in food products and resources
Nechyba, Ondřej ; Benešová, Karolína (referee) ; Vespalcová, Milena (advisor)
This master‘s thesis deals with quantification of vitamin B6 in beverages, food supplements and raw materials in food industry. The literature retrieval part summarizes general information about vitamines, vitamine B6, nicotine acid and vitamine B1. Further on in this part there is described principle of high pressure liquid chromatography and quantification of individual vitamines. In the experimental there are listed used tools, apparatus and chemicals. There is described preparation of idividual samples of food supplements, energy drinks, multivitamine drinks, beers and brewer’s malts. This chapter also contains information about chromatographic separatory systems Shimadzu and SpectraSystem. The quantification was performed by high pressure liquid chromatography on a reverse phase with gradient elution and two ways of detection, fluorescent and spectrofotmetric. The result of experimental activities and vitamine content in analysed samples are presented in the next chapter. In the final contains summarization of results obtained in experimental part. The maser’s thesis was measured in the laboratory of Institute of Food Science and Biotechnology, Faculty of Chemistry, Brno University of Technology.
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Meaning and resource of selenium in human nutrition
KRATOCHVÍLOVÁ, Zuzana
Bachelor's thesis concentrates on functions of selenium in human nutrition. Selenium is an essential trace element of importance to human health. Its availability depends on the concentration of selenium in the soil. The average income of selenium in the Czech population are usually 36 g/day per individuals. Excess or insufficient selenium intakes can result in adverse effects on human health. The most important sources of selenium in the diets of most people are meat, fish, eggs, milk, cereals and nuts. Selenium plays an important role in a number of metabolic functions including antioxidant systems, thyroid hormone metabolism, immune function and reproduction. Low selenium status are associated with increased risk of mortality, poor immune function, and cognitive decline, while high selenium status cause garlic breath, hair and nail loss, disorders of the nervous system and skink and poor dental health. Amount of selenium and its need changes during life. Recommended doses of selenium for women are 55 g/day and for men 70 g/day. Pregnant and lactating women require an average of 65-75 g selenium/day. Selenium deficiency in women causes problems with pregnancy, fetal malformations or postnatal complications. Newborn baby receives in breast milk about 10 g selenium/day. The recommended doses for children are in the range of 20-30 g selenium/day. The lack of selenium in seniors causes loss of muscle mass and strenght. Conversely sufficient doses of selenium can prevent the development of osteoporosis and various health complications. During sport aktivity, in the body there arise a large amount of free radicals and that is why it is necessary to suply the body of a sufficient amount of selenim, which helps prevent with its antioxidant effect oxidative damage of the muscles. The population exposed to low levels of selenium, the lack can be increased by use of dietary supplements with selenium.
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The market of food supplements and their trustworthiness
Hroudová, Martina ; Chylíková, Hana (advisor) ; Turnerová, Lenka (referee)
The bachelor thesis deals with the market of food supplements and their trustworthiness. The aim of this thesis is to inform about the current situation on the market of food supplements in the Czech Republic and abroad, to highlight the importance of consumption of food supplements and to present conclusions obtained during a personal survey. The work could be divided into two parts, the first part is theoretical and the second one practical. The purpose of the first part is primarily to introduce the topic of food supplements and to provide information about the market of the food supplements as well as about the food supplements themselves. The practical part provides information about shopping behavior of customer and about his general knowledge in this area.
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COMPARATIVE STUDY OF FOOD SUPPLEMENTS USED ON THE ACTIVITY OF KINETIC ENDURANCE CHARAKTER APPLIED AS A CARDIOVASCULAR DISEASES PREVENTION
DIČE, Michal
The aim of this thesis is to compare food supplements used on the activity of endurance character and their influence on the cardiovascular system. The teoretical part is pursued to the basic food components and their metabolism and to kinetic activities splitting. The practical part gives information about splitting of sports supplements used on the activity of endurance character, their usage and effects. It deals with the question of human organism behaviour during the strain of endurance character and how the food supplements help to regenerate the human body. Further, it presents a food supplements overview according to their focus and their effect on the human organism during the strain of endurance character. Finally, the summary states which of the specific food supplements are the most optimal for the strain of endurance character.
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