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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.
1

Vitamin E vid prostatacancer

Dobre, Cristina January 2016 (has links)
Sammanfattning Vitamin E är en substans med antioxidanta egenskaper, ett fettlösligt vitamin som kan finnas i naturliga källor såsom vegetabiliska oljor, ägg, grönsaker, spannmål, frukter,kött men också i syntetisk form. I dagsläget är vitamin E också tillgängligt som kosttillskott och används förebyggande och/eller vid behandling av sjukdomar som kardiovaskulära sjukdomar, arterioskleros, diabetes mellitius samt olika former av cancer. Vid intag av vitamin E kan oxidativ stress minskas vilket produceras av fria radikaler (t.ex. joniserande strålning, giftiga föreningar från luft, vatten, mat) som drabbar celler och på det sättet förebyggs och fördröjs uppkomst av sjukdomar. Utöver sin antioxidant effekt och är vitamin E involverat i immunförsvaret, cellsignalering,genreglering samt andra metaboliska processer. Dessa egenskaper har gjort av vitaminE är en intressant kandidat till utredning vid prostatacancer (adenocarcinom), som är den vanligaste tumörformen i Sverige hos män över 50-års ålder. Denna litteraturstudie har för syfte att undersöka det empiriska stödet för tesen omvitamin E kan ha en förebyggande effekt mot prostatacancer och vilka risker som finns vid intag av vitamin E vid prostatacancer. Tidigare forskning har visat att det har enantioxidativ inverkan på kroppens organ och det har därför funnits en tro på att den kan hjälpa förebygga prostatacancer. Litteraturstudien bygger på originalartiklar framförallt från PubMed, Socialstyrelse hemsidan, WebMd, olika medicinska böcker och i Google med sökord som: vitamin E, prostatacancer, tokoferol och prostatacancer,oxidative stress, antioxidant, androgen metabolism och vitamin E, prostatacancer ocharv, androgen och vitamin E. Resultatet av studierna visar att det inte finns ett entydigt empiriskt stöd för att vitaminE (tokoferol) har en förebyggande effekt mot prostatacancer. Vissa studier visar ett stöd för att det finns en förebyggande effekt, andra visar att det inte finns ett stöd och en visar en signifikant ökad risk för prostatacancer vid intag av tokoferol. Prostatacancer kan inte förebyggas med vitamin E (tokoferol) enligt forskningsresultaten i denna studie. Vidare forskning krävs för att se om det kan finnas kombinationer med t.ex. selen för att öka effektiviteten för att förebygga prostatacancer.
2

Analýza biologicky aktivních látek v oleji z meruňkových jader. / Analysis of biologically active substances in apricot oil

Valasová, Denisa January 2017 (has links)
The Master’s thesis is focused on the analysis of biologically active substances in apricot kernel oil. Apricot oil has recently begun to be widely used in the cosmetics industry, particularly as a part of massage oils or as part of moisturizing creams. The aim of this thesis is to characterize and assess the quality of apricot oil, determination of the content of selected active ingredients, through a series of analytical methods, and subsequent use of this oil in cosmetics and food industry. The thesis is based on the comparison of the quality of pure apricot oil and the oil after the fermentation process. It has been found that apricot kernel oil actually contains large amounts of unsaturated fatty acids. The excellent antioxidant activity of apricot kernels was proven too, especially those after fermentation. In addition to antioxidant activity, the samples contain a relatively large amount of tocopherol after the fermentation. Tocopherol is important for the uptake of free radicals in lipid bilayers, thus slowing down aging, protect the membranes and also prevent from possible cardiovascular and oncological diseases. Furthermore, in the Master’s thesis there were confirmed not only the hydration effects of creams with apricot oil, but also their ability of inhibic transepidermal loss of water from the epidermis. Creams were tested on five probands, aged 23–24, with different skin types. After the application of creams to their skin, these properties greatly improved, the skin has been regenerated and hydrated for 24 hours after the treatment.
3

Sledování kvalitativního a kvantitativního zastoupení vitaminů v masozeleninových přesnídávkách určených pro dětskou vyživu

Solčány, Veronika January 2016 (has links)
This thesis deals with the qualitative and quantitative representation of vitamins in the meat-vegetables based infant food. The work is divided into the theoretical and the experimental part. The theoretical part describes a child nutrition and the vitamins. In the chapters, dealing with vitamins, is a description of particular vitamins, their biological functions in the body, the recommended daily dose and their stability during food processing. These chapters concern fat-soluble vitamins (vitamin A, D, E and K) and water-soluble vitamins (B-group vitamins and vitamin C) as well. The work deals with nutrition of infants, toddlers and young children under age of 10 years too. For the each age group there is given the daily recommended dose of vitamins. Experimental part deals with the quantification of vitamins (retinol, ascorbic acid, A-tocopherol and B-carotene) by the HPLC analysis in the samples of the meat-vegetables based infant food. The influence of storage time and conditions (exposure to daylight vs storage in the dark) was measured on concetration of the examined vitamins in the samples. The results were statistically analyzed using software Statistica 12 (Wilcoxon signed-rank test, linear regression, p<0,05) and showed, that all monitored vitamins degrades during storage. The concetration of vitamins in the product is also influenced by the storage conditions (the faster degradation of vitamins occurred in samples exposed to daylight).
4

Sledování obsahu vitaminu E ve vzorcích obilovin / Monitoring of vitamin E content in the samples of cereals

Cibulcová, Pavla January 2017 (has links)
Thesis deals with the analysis of vitamin E in cereal samples, namely barley and wheat and malt produced from them. Selected samples were treated with low-temperature plasma, fungicide and biological treatment to elimination fungus and mycotoxins. The aim of the thesis was to find out the influence of the treatment, the combination of several types of treatment on vitamin E content in grain and malt. If the content of health-positive substances is not reduced and grain can be used for food, malt, or for feed purposes. The theoretical part focuses on the properties, occurrence, biochemistry and importance of vitamin E for living organisms. It also focuses on the properties of cereals that are a significant source of vitamin E. Malt production and sample treatment are also described. The experimental part describes the field experiment, individual types of treatment, extraction of vitamin E from the samples and determination of vitamin E content by high performance liquid chromatography with fluorescence detection. The results are compared with the current literature. It was found that the treatment did not have a significant negative effect on vitamin E content.
5

Vlastnosti komplexů aminojílu a biologicky aktivních látek / Properties of aminoclay complexes and biologically active substances

Dušek, Jakub January 2020 (has links)
This paper builds on previous research of aminoclay complexes in undergraduate studies. Theoretical part deals with study of current problems of aminoclay complexes with bioactive substances and the choice of substances for complexing with aminoclay. The experimental part consists of preparation of aminoclay complexes with selected bioactive agents at various concentrations. Verification of binding of bioactive agents to the aminoclay matrix was performed by Elemental Analysis (EA) and Fourier-transform infrared spectroscopy (FT-IR). For finding of the bound amount of bioactive substance were used the Ultra Performance Liquid Chromatography (UPLC®) and analysis of the cytotoxic properties of the formed complexes by used by the MTT assay. The main motivation of this study is to create new complexes with improved characteristics that would replace existing forms of substances used in pharmaceutical and biomedical applications.
6

Interakce hyaluronanu s hydrofobními soluty / Hyaluronane interactions with hydrophobic solutes

Slezáková, Dagmar January 2008 (has links)
The diploma thesis is based on the study of hydrophobic interactions of the native hyaluronan with selected solutes. On the basis of a literature search were chosen fluorescent probes and fluorescing biologically active substances, which are useful for investigation of colloids as 6-(p-toluidino)-2-naphthalenesulfonic acid (polarity probe), lipophilic vitamin (±)-alpha-tocopherol, pyrene (polarity probe) and finally hydrophilic vitamin riboflavin. In the experimental part of this thesis was studied the influence of solvents with different polarities, or more precisely dielectric constant, on the emission spectra, as well. There were investigated interactions of native hyaluronan with TNS and then interactions, which were influenced by the ionic strength. Such influenced interactions were not observed, that was probably due to the strong solvation´s wrapping of the hyaluronan. Interactions were observed after the process of lyophilisation followed-up by the rehydratation of the samples. For the next study of interactions the riboflavin was chosen and was investigated the REES effect in the native hyaluronan in different concentrations of its different molecular weights. In this case were not observed any shifts in the emission maximum with the excitation wavelenght shift and that is why the interactions of hyaluronan with riboflavin were not demonstrated in the field of chosen concentrations. By using another probe alpha-tocopherol was investigated the associative behaviour of hyaluronan and moreover was observed anisotropy of alpha-tocopherol in different concentrations of different molecular weights of native hyaluronan. The anisotropy reached high values in contrast to the reference solute that was the mixture of glycerol and ethanol. The anisotropy depended more on the molecular weight than on the concentration of hyaluronan. Interactions of hyaluronan were also studied by using the polarity probe pyrene in different concentrations of different molecular weights of the hyaluronan. The pyrene 1:3 ratio did not show the concentration dependence within the chosen concentrations except for the molecular weight 253.9 kg mol–1. Both probes alpha-tocopherol and pyrene were performed by the process of lyophilisation followed-up by the rehydratation, which improved interactions of these probes with hyaluronan.

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