National Repository of Grey Literature 82 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
UV-photochemical generation of volatile compounds of selenium and tellurium
Nováková, Eliška
The presented thesis deals with UV-photochemical generation of volatile compounds of Se and Te from various species. The aim of the project was to expand the current state of knowledge by the application of photocatalytic reduction of higher oxidation states of Se and Te for the speciation analysis based on UV-photochemical generation of volatile compounds. The first step of the study was the assembly of the apparatus for the photocatalysed UV-photochemical generation of volatile compounds. The material of reactor and the whole experimental set-up were based on literature survey and previous research done in our research group. Experiments were directed towards finding the optimum conditions for generation of volatile compounds of selected model elements Se and Te. Se was studied as the element most commonly determined by the UV-photochemical generation of volatile compounds. Conversely, Te was selected as a model analyte representing elements forming less stable volatile compounds. The second part was the application of the optimised method of photocatalysed UV- photochemical generation of volatile Se compound to the determination of Se in water matrices, liquid certified reference materials and also samples of dietary supplements. TiO2/UV-photochemical generation was also successfully modified to...
The selenium effect on secondary metabolites production in in vitro cultures of medicinal plants - II
Ošťádalová, Tereza ; Tůmová, Lenka (advisor) ; Kašparová, Marie (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Candidate: Tereza Ošťádalová Supervisor: Doc. PharmDr. Lenka Tůmová, CSc. Title of diploma thesis: The selenium effect on secondary metabolites production in in vitro cultures of medicinal plants - II. Key words: callus, suspension culture, abiotic elicitor, selenium, Fagopyrum In vitro plant cultures usually produce only a small amount of secondary metabolites. The method of elicitation is one of the options how to increase the production of these substances. The effect of selenium as abiotic elicitor on rutin production in callus and suspension culture of Fagopyrum esculentum Moench., variety Pyra was observed in this study. The release of rutin into the nutrient medium was studied as well. The cultivation was performed in Murashige and Skoog (MS) nutrient medium which was enriched with 1 mg/l of 2,4-dichlorophenoxyacetic acid. The solution of selenium in three different concentrations (c1 = 9.012.10-3 mol/l, c2 = 9.012.10-4 mol/l, c3 = 9.012.10-5 mol/l) was used. The samples were taken after 6, 12, 24, 48, 72 and 168 hours of elicitor treatment. The rutin content was determined by high-performance liquid chromatography (HPLC). The elicitation led to increasing of rutin amount in callus and also in suspension...
Comparison of selenium extraction efficiency from food supplements
Molnárová, Lucia ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
The aim of this bachelor thesis was comparison of selenium extraction efficiency from food supplements which contain various declared forms of selenium. The method of atomic absorption spectrometry with flame atomization was used to determine the efficiency of the extraction. The first step for the determination of selenium in four real samples was the experimental finding of optimal conditions for selenium determination by flame AAS technique. Optimized parameters included the flame composition, the fuel flow rate, the angle of burner rotation, the horizontal burner position and the spectral range. During the testing the flame composition, higher responses were measured by using air as an oxidant, and therefore acetylene-air flame was used to other optimize and measure real samples. After optimization of the conditions, the calibration dependence was determined and the basic characteristics of the measurements were calculated. The detection limit and determination repeatability, sensitivity and operating range were determined for selenium determination. The detection limit was 0.12 mg dm-3 . The real samples of the food supplement tablets were mechanically homogenized and transferred to aqueous solutions, which were subsequently analyzed by the optimal conditions. The highest extraction efficiency...
Nutrition in thermic injury
Zemanová, Markéta ; Zajíček, Robert (advisor) ; Novák, František (referee)
Výživa u termických úrazů [Nutrition in Thermic Injury]. Bc. ZEMANOVÁ, Markéta, DiS. Praha, 2017. Počet stránek 84, 2. Diplomová práce (Mgr.) Univerzita Karlova, 1.lékařská fakulta Obor: Nutriční specialista Vedoucí práce MUDr. Robert Zajíček, Ph.d Abstract Aim of the thesis is summarizing current knowledge about clinical nutrition of patients with severe thermal injuries. Special emphasis is given to specifics of pediatric patients, who in many aspects react differently. The introduction focuses on history of burn medicine including nutrition, classification of burn injuries, prehospital care and role of individual members of the therapeutical multidisciplinary team logically centring on role of the dietitian. Extreme hypermetabolism, persisting a year or longer after the insult, influences nutritional recommendations including energy, macronutrients (protein, fats and carbohydrates) and micronutrients (minerals, vitamins and trace elements). Mode of administration is influenced as well. Specific facts are shown how these characteristics are reflected in daily dietetic therapy at the Clinic of Burn Medicine of the Prague Vinohrady Faculty Hospital (FNKV). In the investigative part we compare two groups of adult patients with extensive burn injuries. Inclusion criteria were age of 18-65 years, extent of...
UV-photochemical generation of volatile compounds of selenium and tellurium
Nováková, Eliška ; Hraníček, Jakub (advisor) ; Komárek, Josef (referee) ; Šíma, Jan (referee)
The presented thesis deals with UV-photochemical generation of volatile compounds of Se and Te from various species. The aim of the project was to expand the current state of knowledge by the application of photocatalytic reduction of higher oxidation states of Se and Te for the speciation analysis based on UV-photochemical generation of volatile compounds. The first step of the study was the assembly of the apparatus for the photocatalysed UV-photochemical generation of volatile compounds. The material of reactor and the whole experimental set-up were based on literature survey and previous research done in our research group. Experiments were directed towards finding the optimum conditions for generation of volatile compounds of selected model elements Se and Te. Se was studied as the element most commonly determined by the UV-photochemical generation of volatile compounds. Conversely, Te was selected as a model analyte representing elements forming less stable volatile compounds. The second part was the application of the optimised method of photocatalysed UV- photochemical generation of volatile Se compound to the determination of Se in water matrices, liquid certified reference materials and also samples of dietary supplements. TiO2/UV-photochemical generation was also successfully modified to...
Vliv dotace mikroprvků u masného skotu na parametry užitkovosti a koncentraci mikroprvků v krvi telat
Kořínek, Matěj
Aim of this thesis was to evaluate influence of inorganic selenium given, in a form of mineral supplement compound, to cows and their calves in order to supply their organism with selenium and also for the utilitarian traits. These were divided into two groups of six and supplemented with two different forms of selenium: group A was given inorganic sodium selenite, group B was given organic selenomethionine. Cows that were examined before the start of supplementation had average activity GPX in blood samples from group A 847,06 +- 170,77 ukat/l and group B 791,30 +- 91,20 ukat/l and concentration of Se of group A: 136,70 +- 27,97 ug/l and group B 95,77 +- 20,05 ug/l. It was found that cows postpartum had higher activity of GPx by 26% in group A and by 45% in group B. Difference between groups was statistically inconclusive (p < 0,28). Increase in concentration of selenium in blood of cows in group A was 7,5% and in group B 5%. In blood of newborn calves of both groups was not found conclusive difference of GPx (p < 0,43). Concentration of selenium in group calves A 160,18 +- 18,07 ug/l and group B 105,30 +- 24,26 ug/l. Difference in concentration of selenium in blood of cows and calves was statistically conclusive (p < 0,05), but because this difference was conclusive already before the supplement compound was given both inorganically and organically bound selenium, this result cannot be interpreted as conclusive influence of different forms of selenium supplemented. Weight and weight gain of calves were balanced between groups and statistically did not differ (p < 0,39). It can be concluded that both forms of selenium had analogical biological effect on focused parameters.In blood of newborn calves no conclusive difference in GPx was found
Uplatnění vybraných forem selenu při pěstování máku setého (Papaver somniferum L.)
Tobek, Ladislav
Selenium is an essential element for human organism. One of the possible ways to increase its quantity in food is a biofortification of crops. Czech Republic is the largest producer of poppy seeds in the world, it could be therefore viable to increase the nutritional value of selenium in this crop. The goal of this thesis was a recognition of suitability of selected forms of selenium for biofortification of seeds of opium poppy (Papaver somniferum). Aside from the distribution of selenium in the plant of poppy and its accumulation in the harvested seeds this study also investigates the effect of its soil and foliar application on the yield and weight of a thousand of seeds. The selenium was applied into the soil in 150, 300, and 600 g Se.ha-1 doses in the form of SeO32- and SeO42- in our one-year container experiment. The same forms of selenium were also applied foliarly in the 20 and 40 g Se.ha-1 doses in our one-year small-plot experiment. It is evident from the analysis of the distribution of selenium in the individual parts of the plant that selenite was accumulated primarily in the lower part of the plant (stalk and leafs) and only a maximum of 25.1% of the total was integrated in the capsule. Selenium, in the form of selenate, was contained in the capsule at a rate of 39.9 to 62.6% of the overall weight of the selenium contained in the whole plant. Soil and foliar application did not influence the yield and weight of a thousand of seeds. In both the container and field experiment the application of an increasing amount of selenium in the form of both selenite and selenate has significantly increased its presence in the harvested seed. Our results suggest that selenate is a better form of selenium for the biofortification of poppy.
Metabolismus mikroprvků ve vztahu matka - mládě u přežvýkavců
Zającová, Karolína
The main aim of my bachelor thesis, was execute literary recherche about the most famous trace elements: selenium, zinc, copper and manganese, which are the most important trace elements in metabolism and also in relationship between mothers and kids. In my bachelor thesis I described their functions in many metabolic processes. Also the deficiency and redundancy was described in this topic. The second part of this bachelor thesis, I described differences between concentration in mother´s and kid´s blood in ruminants and tried to propose the right diagnostic changes, for evaluate the status of these elements in kid´s blood system.
Efekt selenu na antioxidační status organismu po porodu
Wronková, Sabina
The aim of this thesis was to develop a literature search and experimentally determine the effect of organic forms of selenium levels (0.3 and 0.6 mg/kg FM) of selenium on the antioxidant status in postpartum sows. Experiment included 18 sows in the postpartum period, which were divided into three groups according to age. The model animals were divided into three groups. The first group (Se1) sows (n = 6) served as a control, wherein the addition of selenium has not been increased. The second group (Se2) sows (n = 6) were fed 0.3 mg Se/kg FM. Third group (Se3) sows (n = 6) were fed 0.6 mg Se/kg FM. Premix was dosed in the morning feeding. To supplement selenium were used selenium enriched yeast (Sel-Plex - Alltech's). The results show that the dose of selenium in an amount of 0.30 and 0.60 mg/kg FM, increase the activity of antioxidant enzymes, glutathione peroxidase and superoxide dismutase. Glutathione peroxidase (GPx) after supplementation with 0.3 mg/kg selenium increased from the second sampling, but the third sampling was statistically significant (P <0.05). Doses of 0.6 mg/kg selenium also visibly increased level of glutathione, but these results can not be statistically demonstrated. Superoxide dismutase (SOD) at both doses (0.3 and 0.6 mg/kg) appeared selenium statistically not detectable visible growth. We also found an increase of antioxidant activity measured by the methods ABTS, FRAP and FR, although the methods ABTS and FR showed slight fluctuations. The amount of reduced and oxidized glutathione were also significantly (P <0.05) higher in both experimental groups. The selenium content of selenium supplementation significantly affected when the results of both experimental groups were statistically significant (P <0.05) higher. Level malonyldialdehydu (MDA) after supplementation with 0.3 mg/kg selenium statistically proven (P <0.05) increased in the third collection at 0.6 mg/kg selenium, we observed statistically demonstrable (P <0.05) increase from the second collection. We can therefore conclude that selenium supplementation in organic form, can reduce oxidative stress in confinement of sows and overcome this stressful period for the organism.

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