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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.
31

Stanovení oxidačních produktů bilirubinu / Determination of bilirubine oxidation products

Čepa, Adam January 2013 (has links)
This thesis is focused on protective and antioxidant properties of bile pigment bilirubin. Bilirubin is a potent scavenger of free radicals and reactive oxygen species generated by increased oxidative stress. Mildly elevated systemic levels of bilirubin are actually associated with lower incidence of oxidative stress-mediated diseases, such as cardiovascular disease, atherosclerosis, diabetes and certain types of cancer. The main aim of this thesis was to prepare bilirubin oxidation products in vitro, characterize their physical-chemical properties and thein determine biological impact.
32

Vliv ošetření elicitory na obsah některých biologicky aktivních látek ve vybrané rostlině / The effect of the treatment with elicitors on the content of some biologically active constituents in chosen plant

PETR, Jindřich January 2014 (has links)
The aim of this thesis was to study the effect of the acetylsalicylic acid on the stimulation of plant immunity and thus the influence on the content of the active constituents in Silybum marianum L. plants. The main active constituents of Silybum marianum L. seeds are silybine, silydianine, isosilybine, silycristine, usually expressed as silymarine content, and taxifoline. These constituents have antihepatotoxic effect and many different protective effects on numerous organs and cells. Knowledge about stress and elicitation, origin, botanical characterization, growth, development and cultivation of Silybum marianum L. were summarized before the research.The small-plot experiment was set up in Hluboká nad Vltavou in 2013. Plants of Silybum marianum were divided into four groups and then three goups were treated three times during the vegetation with the acetylsalicylic acid of three different concentrations - 10-3 mol.l-1 (high), 10-4 mol.l-1 (medium) a 10-5 mol.l-1 (low). Every single one group was treated with only one concentration of the acetylsalicylic acid. The last group was treated only with water and served as a control group. The preparation of the extracts was being held with using mixture of acetone, methanol and water. The extracts were determined by High Performance Liquid Chromatography.The effects of each chosen concetration of acetylsalicylic acid (high, medium, low) on the active constituents in seeds were not statistically proven compared to seeds without aplication of the elicitor (control group). The ineffectiveness of the elicitor should have been also caused by nonoptimal condition of plants due to various abiotic and biotic stressors.
33

Extrakce antioxidantů z bezových květů a úchova extraktu pro další možné využití / Extraction of antioxidants from the elderberry blossom and preservation of the extract for further possible use

Krůzová, Sabina January 2018 (has links)
The thesis deals with the extraction of antioxidants from elder flowers and the way of storage obtained extract. The elder flowers which are obtained by cutting trees as a waste product and after their processing it could be used as an ingredient to cosmetics products for body and face skin or in a spa like additive to baths. In theoretical part are information about black elder, its botanical characteristics, utilization and about substances contained in it. There is also a chapter about lyophilization as a method which was used for concentration of extract. The last chapter describes theoretical information about liquid chromatography because this method was used for analysis of contents of extract. Experimental part describes optimalization steps in preparation of extract. It was found that the biggest content of polyphenolic compounds was when the proportion between flower and water was 1:10, optimal temperature of water for extraction is 100 °C and it was also found that the time of extraction don´t have any influence on content of polyphenols. Thanks to the lyophilization it was obtained dry light brown powder which is stable for long time. The lyophilizate was tested for some physical properties like pH, refractive index, solubility etc. There was also determined antioxidant activity by DPPH method and there was found quenching activity is 64,9 %. In determining of heavy metals in sample was found trace amounts of lead and chrome. By liquid chromatography was determined content of polyphenols, caffeic acid was in an amount 59,6 mgl1, chlorogenic acid 398 mgl1 and ferulic acid wasn´t detected. All of analysis was for 1% solution of extract because to cosmetic it could be just this amount to addition. In the last step was prepared a skin lotion with elder flower extract and it was tested for stability also was prepared an ointment from pork lard.
34

Stanovení těžkých polycyklických aromatických uhlovodíků v půdách a sedimentech / Determination of heavy polycyclic aromatic hydrocarbons in soils and sediments

Cáhová, Miroslava January 2008 (has links)
This diploma thesis will be focused on the identification and quantification of PAHs with molecular mass exceeding 278 Da by separation and spectrometric methods available at the laboratories of ICTEP.
35

Sorpce PCP na lignitu / PCP sorption of lignite

Šnédarová, Gabriela January 2008 (has links)
Within the framework of this diploma thesis, the sorptive capability of a lignite as a natural adsorbent was applied on an aqueous solution of pentachlorophenol. The aqueous solution of this substance, which is very dangerous for the environment, was prepared in various concentration ranges according to reached solubility. The solubility is noticed in different literatures variously and then is not applicable. That is why it was necessary to find out the ”real“ solubility. The aqueous solution of pentachlorophenol of given concentration was subsequently put to adsorption with exactly defined quantity of the lignite and as a result the adsorptive isotherms were obtained. These isotherms represent the adsorption capability in dependence on the adsorption duration, quantity of used lignite and concentration of pentachlorophenol solution. By the adsorption with duration longer than one hour, the quantity of adsorbed PCP does not increase markedly.
36

Benzen v benzinech z hlediska ochrany zdraví / Benzene in petroleum-derived products and health protection

Bílková, Karolina January 2008 (has links)
Benzene is very toxic compound, which has carcinogenic and mutagenic effects. Result of these effects is significant reduction of its use and also low hygienic limits in occupational environment and environment. The aim of this diploma thesis was to map out possible exposure to benzene and checking of clasification correctness of motor gasoline and benzine (cleaners, thinners etc.). Determination of benzene was carried out by gas chromatography with flame ionisation detector (GC/FID) and high performance liquid chromatography with diod array detector (HPLC/DAD). Marginally, the diploma thesis was focused on determination of toluene (in june 2007 became effective ordinance no.284/2006 Sb., which forbid to sell products that contain more than 0,1 % of toluene to small consumers). Toluene was determined by same methods as benzene.
37

Stanovení vybraných fytofarmak a jejich metabolitů v odpadních vodách / Determination of selected phytopharmaceuticals and their metabolites in waste waters

Nevědělová, Klára January 2008 (has links)
This diploma thesis will be focused on the identification and quantification of selected phytopharmaceuticals ant theri transformation products using separation and spectrometric methods available in the laboratories of ICTEP.
38

Posouzení kontaminace kalů z čistíren odpadních vod rezidui léčiv / Assessment of contamination of sewage sludge from wastewater treatment plant by drug residuals

Dvořáková, Petra January 2009 (has links)
The aim of diploma thesis was finding of the method for the determination of drug residua in sewage sludge from wastewater treatment plant. Selected sulfonamide and diaminopyrimidine antibiotics, which are used in human and veterinary medicine, were selected as target comopounds. They are discharged to the sewer systems together with the urine and faeces and enter the sewage treatment plant, where they are not completely removed. They can be found in treated waste water or in sewage sludge. They can enter to the environment, where they can induce negative effects on organisms in soil and water ecosystem. An optimized method was used for identification and determination of these antibiotics in real samples from the large-scale waste water treatment plant in Brno-Modřice and from the waste water treatment plant situated in the area of Veterinary and Pharmaceutical University Brno. Antibiotics were extracted from sewage sludge by ultrasonic and by pressure solvent extraction (PSE). Waste water and sewage sludge real samples were concentrated and cleaned by solid phase extraction (SPE). For determination these antibiotics high performance liquid chromatography with diode array detector (HPLC - DAD) was used.
39

Změny ve složení mléka po dotaci dojnic vybraným aditivem / Milk composition changes after fortification milch cow feed with selected additive

Tůmová, Michaela January 2010 (has links)
This thesis is dealing with effect of supplement limiting aminoacid histidin, that was applied as duodenal infusion, on yield and composition of high production dairy cows milk. The theoretical part describes overview about milk composition and metabolism of dairy cows. There are described nutrition requirements of dairy cows for esential aminoacids. In this part are also presented principles of analytical methods used for analysis of milk. For determination of basic components of milk were used infrared spectroscopy and enzymatic-conductometry. Aminoacid profile of casein was determined by ion exchange liquid chromatography. In the experimental part is described method of experiment. There is described technique of acid and oxidative hydrolysis of lyofilized casein and technique of determination aminoacids in this hydrolyzated casein. Results of analysis were interpreted and discussed with literature. This diploma thesis was made as a cooperation between the Institute of Food Science and Biotechnology, the Faculty of Chemistry, University of Technology, Brno and the Research Institute for Cattle Breeding, Department of Animal Physiology and Nutrition, Pohorelice.
40

Analýza nápojů slazených extrakty stévie cukerné / Analysis of drinks sweetened with stevia extracts

Procházka, Václav January 2013 (has links)
The steviolglycosides are the natural, sweet substances from Stevia rebaudiana Bertoni. It affect human health positively and its sweetness is 300x stronger than the sweetness of sucrose. That's why it's used to sweetening the commercial products. Because of its potential properties it's good to have an appropriate method to isolate it. High performance liquid chromatography ( HPLC) is based on the separation of analyte between two immiscible phases with high pressure pump and appropriately chosen stationary phase in the column. Than the analytes come out from the column in different retention times. This master´s thesis follows up selection of the best HPLC system for isolation of the main steviolglycosides and its analysis in commercial products. In the theoretical part of the thesis is described the origin, basic characteristics, botanical description, cultivation and affect to the human health of Stevia rebaudiana Bertoni and its use in food industry. There are also concisely characterized the sweet substances contained in the plant, so called steviolglycosides. Than there are given the theoretical basics of high performance liquid chromatography, HPLC instrumentation and its specific applications at sleviolglycosides with the basic chromatographic parameters. The object of the first experimental part was to research the optimum conditions for time and separation effective chromatographic analysis and select the best chromatographic system for isolation of steviolglycosides. In the second experimental part, I have compared and defined the main steviolglycosides (stevioside, rebaudioside A) in nine selected products, commercially available in Czech republic, with the best chromatographic method. In these products was the contain of the stevioside or rebaudioside A confirmed or refused.

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