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Crosslinking of thermosensitive functionalized copolymers by blue light
Křivánková, Nikola ; Michlovská, Lenka (referee) ; Vojtová, Lucy (advisor)
Cílem mé bakalářské práce byla příprava hydrogelu s hybridní sítí pouze z jednoho typu biodegradovatelného kopolymeru. Nový degradabilní hydrogel, obsahující jak fyzikální interakce (vznikající při fyziologické teplotě 37 °C), tak i chemické vazby iniciované modrým světlem by mohl být využit jako resorbovatelný kryt ran nebo jako injektovatelný nosič s postupným a velice dobře řízeným uvolňováním léčiv. Termocitlivý PLGA–PEG–PLGA kopolymer syntetizovaný živou polymerací za otevření kruhu byl následně funkcionalizován anhydridem kyseliny itakonové za vzniku ITA/PLGA–PEG–PLGA/ITA makromonomeru citlivého jak na světlo, tak i na změnu teploty. Při teplotě 37 °C tvoří kopolymer díky hydrofobním interakcím micelární síť. Dvojné vazby kyseliny itakonové, která je navázaná na koncích kopolymerního řetězce, umožňují fotochemické zesítění micel a zvýšení tak hydrolytické stability hydrogelu. Syntetizované kopolymery byly charakterizované metodami GPC a 1H NMR. Vznik fyzikální sítě při fyziologické teplotě byl potvrzen reologickou analýzou. Fyzikálně zesítěný ITA/PLGA–PEG–PLGA/ITA hydrogel byl následně, v přítomnosti hydrofilního fotoiniciátoru LiTPO, ozářen modrým světlem (o vlnové délce 430–490 nm) a chemicky charakterizován pomocí ATR-FTIR. Vzniklý hydrogel byl transparentní, ohebný, absorboval až 1176 % vody a ve fyziologickém roztoku při 37 °C byl stabilní 20 dní. ITA/PLGA–PEG–PLGA/ITA hydrogel s hybridní sítí byl rovněž připraven v přítomnosti síťovadla, které výrazně snížilo dobu potřebnou na zesítění hydrogelu, nicméně další analýzy jsou potřeba k podrobnějšímu pochopení principů nových typů hydrogelů.
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Dynamics of yeast colony differentiation: New approaches
Jurečková, Gabriela ; Palková, Zdena (advisor) ; Zimmermannová, Olga (referee)
The yeast Saccharomyces cerevisiae when growing on solid medium forms structured colonies. During its development, two subpopulations of cells are formed, termed as U cells ("upper cells") and L cells ("lower cells"). This nomenclature derives from their position within the colony. These cells differ from each other considering their morphology, metabolism, physiology and are characterized by varying degrees of resistance to stress. This diploma thesis deals with new methodological approaches that can be used in further research of yeast differentiation. The first part deals with yeast differentiation and de-differentiation. In the experimental part, the development of mechanically mixed yeast colonies was monitored. The development was monitored in situ in the colony section using fluorescence and "wide-field" microscopy. The ability to de-differentiate of already specialized cells was evaluated mainly according to the nature of the expression of the fluorescently labeled protein Ato1p, which serves as a protein marker of U cells. The second part deals with the optogenetic system EL222 and its possible use in yeast. Many optogenetic tools have been described to control various cellular processes using light. One of these optogenetic tools is the EL222 system, which allows the induction of...
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The effect of evening exposure to blue light on sleep quality
Baumová, Nikola ; Šteffl, Michal (advisor) ; Bunc, Václav (referee)
Title: The effect of evening exposure to blue light on sleep quality Objective: The main aim of this bachalar thesis is to compare and determine the effect of exposure to blue light in the evening on the quality and parameters of sleep using the results obtained from previous studies dealing with evening exposure to blue light on sleep quality. Methods: The bachalar thesis was carried out as a systemastic review. The source of information were scientific articles and studies from the electronic database PubMed and scientific literature related to the issue. Results: Exposure to blue light in the evening decreased the quality and parameters of sleep. These negative effects were eliminated by using blue light blocking glasses. Keywords: Blue light, sleep, blue light blocking glasses, melatonin
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Design of the morning sun simulator
Suský, Stanislav ; Krbal, Michal (referee) ; Štěpánek, Jaroslav (advisor)
This work deals with the introduction of the influence of electromagnetic radiation on circadian rhythms and their influence on the organism. The work describes circadian rhythms and their influence on the organism, the location and description of functions of important organs and the influence of electromagnetic radiation on these organs. There are described light sources and their influence on circadian rhythms.
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The effect of the blue light on the human body
Dvořák, Petr ; Krbal, Michal (referee) ; Štěpánek, Jaroslav (advisor)
This thesis explains the term „blue light“. It deals with the sources of blue light and the effects of this type of electromagnetic radiance on human body. The focus is concentrate especially on problems, which are evocated of blue light. The biggest danger is the desynchronization of circadian rhythm and photochemical damage of retina – photoretinitis („blue light hazard“). The basic principles of biological processes and the visual system are described here. These processes are controlled by properties of incident light onto the retina of eye. The basic information about artificial sources of blue light commonly used in households and in industry are mentioned in the second half of work. These light sources were measured and elaborated. The electromagnetic spectrums of sources are portrayed and there is a comparison of sources due circadian effect too.
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