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Mechanisms of membrane protein quality control in the endoplasmic reticulum
Jirout, Matěj ; Stříšovský, Kvido (advisor) ; Bařinka, Cyril (referee)
Integral membrane proteins (IMPs) undergo extensive quality control (QC) within the endoplasmic reticulum (ER) to maintain ER proteostasis and the integrity of the ER proteome. ER-associated ribosome quality control (ER-RQC) responds to ribosome stalls during translocation and helps "de-clog" blocked translocon. ER-associated degradation (ERAD) targets misfolded IMPs for proteasomal degradation. ERAD-resistant IMPs are degraded by different ER-phagic pathways, collectively referred to as ELRAD (ER-to-lysosome associated degradation). Coordination of these mechanisms is facilitated by the unfolded protein response (UPR), although UPR receptors are most likely not activated by aberrant IMPs, as all these mechanisms function in the QC of ER-luminal proteins.
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Determination of active substances and possible degradation products in a historical sample of Algena from 1981
Bauerová, Markéta ; Nesměrák, Karel (advisor) ; Kozlík, Petr (referee)
The Algena tablet was an over-the-counter drug in the second half of the twentieth century in Czechoslovakia. Algena was mainly used against pain. The tablet contains four active substances: aminophenazone, aprobarbital, phenacetin, and caffeine. The aim of this thesis was to analyse the active substances in the Algena tablet from 1981,determinate theircontent,and possible degradation products.To complete these goals the RP-HPLC method with UV detection had to be involved and optimized.HPLC-MS was used to detect possible degradation products. Separation was performed on the XBridge® BEH C18 column (150×3.0 mm; 2.5 µm), binary elution was used. The first component of the mobile phase was0.1% aqueous solution of acetic acid and the second component was methanol. The determined contents of active substances (decelerated by the manufacturer) were: amino- phenazone 97.0%,aprobarbital89.2%, phenacetin 96.0% and caffeine 93.2%.Degradation products of the active substances were not detected by HPLC with MS detection. Key words: Algena, aminophenazone, aprobarbital, caffeine, degradation, phenacetin, RP-HPLC
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Characterisation of proteins whose degradation is necessary for normal course of embryonic genome activation in mammals
Svobodová, Nika ; Toralová, Tereza (advisor) ; Krejčová, Tereza (referee)
Early embryonic development is controlled by maternal mRNAs and proteins synthesized during oogenesis. A key period for preimplantation development is the transition from maternal control of development to embryonic control. This process, known as maternal-to-zygotic transition (MZT), requires the coordinated degradation of accumulated maternal mRNAs and proteins and subsequent embryonic genome activation (EGA). Maternal mRNAs are gradually removed from the embryo, but the degradation of maternal proteins is not well understood yet. In mammals, only a few proteins are known whose degradation is necessary for normal course of EGA. The activation of the embryonic genome is closely related to the reorganization of chromatin structure. The initiation of gene expression requires the loosening of chromatin at the gene region and the presence of appropriate transcription factors. Maternal proteins that need to be degraded for the normal course of EGA are involved in regulating chromatin structure and the translocation of necessary factors. This thesis aims to characterize selected proteins (PIASy, CBX5, TAB1 and H1FOO) and describe the role they play during the transition from maternal to embryonic control of development. While PIASy, CBX5, and H1FOO need to be degraded to loosen the chromatin structure...
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Effect of pollutants and concrete quality on durability and service life of reinforced concrete structures
Mazán, Tomáš ; Láník, Jaromír (referee) ; Hrabová, Kristýna (advisor)
The thesis describes the effects of an aggressive environment on structures in infrastructure that are exposed to adverse influences. The theoretical part of the thesis deals with the classification of different aggressive environments and the chemistry by which they cause degradation of concrete and structures. A substantial part is devoted to the interaction of degradation mechanisms, i.e. the synergistic effect. The practical part describes the experimental procedure, the test methods used and the experiment by which the thesis verifies the theoretical ideas. Based on the theoretical background, the thesis develops a model that simulates the effect of the environment. The execution of the experiment consists in simulating aggressive environments and detecting their influence on the investigated properties. After obtaining the results from the tests in the practical part, the risks that may reduce the durability of the structure are subsequently evaluated with respect to the different phases of the life cycle of the structure. Furthermore, the risks that have a significant impact on durability are evaluated and once arranged, measures are proposed. Finally, the thesis discusses the achieved results of the whole experiment and evaluates how to achieve the reduction of the adverse effects in the different phases of the life cycle of the structure.
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Laboratory tests of the degradation of selected sedimentary rocks as a result of their water saturation
Nagyová, Noémi ; Havlíček, Jaroslav (referee) ; Chalmovský, Juraj (advisor)
The work deals with laboratory tests of selected sedimentary rocks and consists of two parts, theoretical and practical. The first part describes the process of "slaking," in which geomaterials disintegrate during repeated cycles of wetting and drying. Than the appearances and types of "slaking," are described as same as the possible main causes of degradation, and the various methods for measuring this phenomenon are described. In the practical part, one-dimensional compressibility tests and grain size analyses were carried on. Compressibility tests were performed in the standard way until the prescribed pressure. In the next loading step, the sample was saturated while maintaining constant pressure, and the volumetric changes were continuously measured. Loading continued when the values were stabilized and for the rest of the test, the sample was kept submerged under the water surface. Within the proposed testing program several tasks were evaluated. One of them wasthe influence of the pressure during saturation, as same as the duration of saturation, the initial porosity number and the sample dimensions. Grain size analyses were performed before and after the compressibility tests. After all this it was possible to determine the structural changes performing by particle disintegration due to the "slaking" effect.
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Microscopic and spectroscopic analysis of elementary 2D materials
Jeřábek, František ; Procházka, Pavel (referee) ; Kolíbal, Miroslav (advisor)
Tato práce se zabývá analýzou struktur tvořených při depozici fosforu na monokrystal mědi Cu(111) za podmínek ultravysokého vakua. Součástí práce je komplexní shrnutí aktuálního pokroku v oblasti syntézy černého a modrého fosforenu. Kromě samotných metod přípravy je diskutována také předpovězená stabilita těchto struktur. V práci jsou prezentovány výsledky analýzy tří struktur pomocí skenovací tunelové mikroskopie a spektroskopie, prokazující možnost přípravy jednovrstvého modrého fosforenu na měděném substrátu. In-situ analýza stability připravených struktur pomocí skenovací tunelovací mikroskopie prokazuje velmi rychlou degradaci modrého fosforenu i za podmínek ultravysokého vakua.
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Effect of enzymes on the degradation of thermosensitive copolymers for controlled release of drugs
Dávidíková, Anna Mária ; Michlovská, Lenka (referee) ; Vojtová, Lucy (advisor)
Termocitlivé hydrogély, ktoré sa používajú ako nosiče liečiv v dnešnej dobe zažívajú obrovský záujem v spoločnosti. Používajú sa ako spôsob dopravy liečiva na predom určené miesto a po dosiahnutí určeného miesta slúžia ako dlhodobé úložisko liečiv v tele. Vlastnosti hydrogélov môžu byť upravované tak, aby dokázali naviazať rôzne druhy liečiv, aby boli citlivé na rôzne vonkajšie impulzy a aby degradovali pomalšie, čo predĺži životnosť liečiv v tele. Aby sme vedeli, ako upraviť vlastnosti hydrogélov a ako sa budú správať, musíme poznať ich degradačný proces a chovanie v rôznych degradačných médiách. Práve preto sú degradačné štúdie veľmi dôležitou súčasťou štúdií hydrogélov. Táto bakalárska práca je zameraná na sledovanie degradácie rôznych roztokov termocitlivého hydrogélu vo viacerých degradačných médiách. Teoretická časť práce zahrňuje krátky prehľad o tom, čo sú to termocitlivé hydrogély, ich charakterizácia a popis vlastností spolu s použitím hydrogélov ako nosičov liečiv. Ďalej sa teoretická časť venuje degradácií hydrogélov celkovo ako aj degradácií konkrétne použitého hydrogélu v tejto bakalárskej práci. V prvom rade bol syntetizovaný živou polymeráciou za otváraním kruhu v inertnej atmosfére termocitlivý PLGA-PEG-PLGA kopolymér, tvorený poly(mliečnou-co-glykolovou kyselinou)-b-poly(ethylen glykolom)-b-poly(mliečnou-co-glykolovou kyselinou). Následne bol kopolymér charakterizovaný na protónovej nukleárnej magnetickej rezonancii a na gélovej chromatografii. Z nasyntetizovaného kopolyméru boli pripravené tri vodné roztoky hydrogélu o rôznych koncentráciách a to 10, 15 a 20 hm %. Vzorky pripravených hydrogélov za teploty 37 , boli degradované v rôznych degradačných roztokoch (UPW (ultra čistá voda), NaCl, PBS (fosfátový pufr) a roztok PBS s enzýmom). Degradačná štúdia bola hlavným cieľom tejto bakalárskej práce. Jednotlivé vzorky boli odobrané v konkrétne stanovené časy a to po 1, 2, 3, 7, 9, 14, 16, 21, 23 a 30 dňoch. Pri vzorkách s enzýmom bola predpokladaná rýchlejšia degradácia vzoriek, tak tieto odbery boli nastavené po 1, 2 a 3 dňoch. Ďalším cieľom tejto práce bola analýza odobraných vzoriek hydrogélov po degradácií na gélovej chromatografii a analýza degradačných médií na kvapalinovej chromatografií s hmotnostným spektrometrom. Počas degradácie vzoriek bola prevedená taktiež gravimetrická analýza a pri odoberaní degradačných roztokov bolo merané ich pH. Následne boli všetky získané dáta vyhodnotené a bolo sledované, či enzým urýchľuje PLGA-PEG-PLGA hydrolytickú degradačnú kinetiku. Výsledky poukazujú na to, že enzým má nízky vplyv na rýchlosť degradácie. Výsledky tejto práce poslúžia ako základy pre budúce degradačné štúdie.
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Study on biodegradation of synthetic biobased polyesters
Guziurová, Pavlína ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
Tato práce se zabývá degradačními vlastnostmi polyesterových polymerů (PBS s inkorporovaným dilinoleovým sukcinátem v různých hmotnostních procentech) v simulovaných tělních tekutinách a odhaluje menší změny vlastností. Byla zkoumána také bakteriální degradace a analýza ukazuje významnější rozdíly ve výsledcích gelové permeační chromatografie (GPC) a skenovacího elektronového mikroskopu (SEM). Zatímco převažuje abiotická degradace, bakteriální prostředí vede k vyšším úrovním degradace než simulované tělní tekutiny, což naznačuje potenciální využití v obalové technice nebo zemědělství. Nižší náchylnost na abiotickou degradaci však otevírá nové možnosti pro další výzkum mechanismů bakteriální a enzymatické degradace pro ekologicky udržitelné alternativy v různých průmyslových odvětvích.
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Determination of climatic factor on the degradation of various solar cells types
Peroutka, Tomáš ; Jandová, Kristýna (referee) ; Vaněk, Jiří (advisor)
In this work are discussed photovoltaic cells. There are also discussed basic concepts of radiation source for solar cells. Also mentioned the issue of semiconductors and even the history and evolution of the solar cells. A large part deals with possibilities of photovoltaic cells degradation. In one chapter is an attempt to bring some types of photovoltaic cells and a description of the production of these modules.The practical part deals with photovoltaic modules degradation and its evaluation. Following part compares measured values with the values provided by producer of photovoltaic modules.
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Degradation of Photovoltaic Modules
Poledník, Tomáš ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
The bachelor diploma thesis is focused on the constructional technology of the solar modules as well as on the problems of the induced degradation under the influence of the potential. It specifies the key issues and possible elements that influence the effect of environment with regard to possible causes of the origin of degeneration. The thesis includes the description of measuring of the polycrystalline and monocrystalline technologies that are resistant to the leading potential. Furthemore, the measuring was carried out on the chosen testing pieces that had been affected by the degradation of the output
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