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Biodegradable polyurethanes based on poly(ethylene glycol)
Kupka, Vojtěch ; Žídek, Jan (referee) ; Vojtová, Lucy (advisor)
Predložená diplomová práce se zabývá syntézou biodegradabilních polyuretanu (bio-PU) na bázi polyethylenglykolu (PEG-u) a polykaprolaktonu (PCL) pro využití k medicínským úcelum. Cílem práce bylo vyvinout metodiku prípravy elastomerního polyuretanu, ze kterého by se dal v budoucnu pripravit skafold (nosic bunek) použitelný v tkánovém inženýrství pro humánní regenerativní medicínu. Teoretická cást práce shrnuje informace o materiálech využitelných pro zamýšlenou aplikaci. Zahrnuty jsou také techniky prípravy skafoldu, jejich biokompatibilita a charakterizace vlastností výsledného materiálu. Praktická cást je pak zamerena na navržení vhodné metodiky pro prípravu funkcních vzorku obsahujících PEG, PCL, hexamethylen-diisokyanát (HMDI) a ethylhexanoát cínatý jako katalyzátor. U pripravených vzorku byl zjištován vliv jejich složení (predevším ruzný obsah a molekulová hmotnost PEG-u) na botnání a hydrolytickou stabilitu spolecne s testováním mechanických vlastností, sledováním kinetiky sítování a stanovením stupne konverze. Morfologie vzorku byla sledována pomocí optické mikroskopie, chemické složení bylo potvrzeno infracervenou spektroskopií a tepelné vlastnosti byly urceny diferencní kompenzacní kalorimetrií. Vývoj v metodice prípravy ukázal, že je nezbytné odstranit pred syntézou z výchozích látek veškeré necistoty, predevším vodu a kyslík, jinak vznikaly nedokonale zreagované vzorky s velkým obsahem póru ruzných velikostí. Syntéza všech vzorku probíhala pod dusíkovou atmosférou ve dvou krocích, kdy v prvním se pouze homogenizovaly oba polyoly (PEG i PCL) na vakuové lince pri 130 °C a ve druhém pak vznikaly výsledné bio-PU za pridání HMDI pri 65 °C v inertní atmosfére manipulacního boxu. Vzorky pak byly dopolymerovány ve forme pri 65 °C pod dobu 48 hodin v sušárne. Ruzné fyzikální podmínky metodiky vedly k príprave jak nepruhledných bílých filmu, tak i vzorku s viditelnou separací fází až po flexibilní transparentní filmy. Pozorování optickým mikroskopem vzorku s fázovou separací prokázalo prítomnost sférolitické struktury krystalické fáze PCL v amorfní fázi matrice PEG-u. Sledování kinetiky sítování pomocí soxhletovy extrakce potvrdilo maximální konverzi polymerace (96 %) již za 4 h dopolymerování v sušárne. Testování zkouškou v tahu ukázalo, že výrazný vliv na pevnost v tahu má isokyanátový index (pomer NCO/OH skupin). Molekulová hmotnost PEG-u ovlivnovala pevnost v tahu jen u vzorku zcela zesítovaných. Merení botnání vzorku ve vode prokázalo, že s rustem molekulové hmotnosti PEG-u roste i obsah vody (od cca 28 až po 58 hm.%) ve vzorcích. Také degradace filmu ve vode pri 37 °C probíhala dle predpokladu rychleji u vzorku s vyšší molekulovou hmotností PEG-u. V predložené diplomové práci bylo potvrzeno, že množstvím a molekulovou hmotností polyethylenglykolu je možné rídit hydrolytickou stabilitu výsledných biodegradabilních polyuretanových elastomeru.
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Microbial characterization of yoghurts and probiotic foods.
Kocourková, Hana ; Burdychová, Radka (referee) ; Španová, Alena (advisor)
Zvýšená konzumace fermentovaných mléčných výrobků v posledních letech vede k zavádění nových výrobků na trh. Funkční a probiotické produkty jsou v dnešní době také hojně rozšířeny. Cílem diplomové práce bylo posoudit mikrobiální kvalitu komerčních jogurtů a nefarmakologických probiotických výrobků. Bylo zkoumáno 24 vzorků jogurtů a 8 vzorků probiotických mléčných výrobků. Pozornornost byla zaměřena zvláště na kvantifikaci mikroorganismů v jednotlivých výrobcích a na sledování viability buněk. Většina mléčných produktů obsahovala počty odpovídající minimální požadované hodnotě 1x107cfu/ml. Nicméně byly objeveny produkty, které neobsahovaly živé bakterie nebo obsahovaly jen jejich menší množství. To platí zejména pro běžné jogurty. Probiotické mléčné výrobky v zásadě obsahovaly větší množství bakterií než jogurty, protože je u nich navíc požadováno 1x106cfu/ml minimálního množství specifických bakterií jiných než jogurtových startovacích kultur. Isoláty z fermentovaných mléčných výrobků byly identifikovány jako Streptococcus thermophilus and Lactobacillus spp. Isoláty byly poté rozlišeny na jednotlivé kmeny pomocí RAPD použitím tří různých primerů. Byla zjištěna velká různorodost mezi kmeny rodu Lactobacillus spp. používaných různými podniky.
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Cutting materials of sintered Carbides end their heat Resistance
Doležalová, Petra ; Bumbálek, Bohumil (referee) ; Osička, Karel (advisor)
One of the fundamental properties of cemented carbides is their resistance to forming and spreading cracks under the thermal stress. The bachelor’s thesis is focused on description of known technological methods that are used for testing of thermal fatigue of materials made by cemented carbides. Part of the bachelor’s thesis is also the description of the thermal fatigue, characterization of the appearance and orientation of cracks that occur in cemented carbides, according to the distribution of the thermal field. Last but not least, the bachelor’s thesis contains the information concerning the problematic of cemented carbides and about their constituents, technology of production and their application.
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Marketing plan proposal for chosen company
Rysová, Markéta ; Průša, Přemysl (advisor) ; Štědronská, Petra (referee)
The diploma thesis focuses on creation of marketing plan for specific project, which offers the services of extreme yachting. The main idea of the project called Evelyna Expeditions is to offer the possibility to participate on the expedition of yacht Evelyna on her journey around the world. Yachting is getting more popular among Czech tourists, but some of them desire even bigger adventure and want to exploit the potential of boat to explore places on the earth which are accessible only from the sea. The project is designed especially for these people. Theoretical part of the thesis explains the different stages of marketing plan (situation analysis, marketing objectives, marketing strategy, budget, action plan) and gives recommendations how to work with them. The practical part of the thesis brings more specific characterization of the project Evelyna Expeditions, for which is subsequently developed the specific marketing plan based on the recommendations outlined in the theoretical part.
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Elementary Children's Practical Knowledge of First-Aid
Hrunková, Lenka ; Kuhnová, Věra (referee) ; Pokorný, Ladislav (advisor)
Providing non-professional first aid to someone in need is part of each human's system of moral and civil obligations. This inspired me largely in the choice of a topic for my diploma thesis. Children of younger school age constitute a group of citizens with moral, but especially civil obligations, and the issues of delivery of nonprofessional first aid also apply to them. Since I study teaching for primary schools, the goal of my thesis is to find out the level of knowledge of first aid among children of younger school age. I chose several conditions which I think children in primary schools should recognize and handle correctly. My thesis is divided into three parts. In the theoretical part 1 deal with educational programs at schools, always with focus on sections dealing with elementary first aid. I used the obtained findings to set up a test that became one of the key tools of my empirical survey. I also characterize the selected conditions, describe their correct handling and list the most frequent handling errors. In the practical part I deal with the first aid test and the implementation of model situations in which children should theoretically and practically demonstrate their knowledge of non-professional first aid for the selected conditions, such as bruises, collapse, anti-shock positions and...
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Studies of nanocrystalline silicon colloidal suspensions
Fučíková, Anna ; Valenta, Jan (advisor) ; Chaloupka, Roman (referee)
This diploma thesis deals with optical and biophysical properties of colloidal suspensions of porous nanocrystalline silicon (por-Si) in different media, conditions necessary to create por-Si with different luminescence peaks and their optical characterization (emission and excitation spectra). The lifetime excited state = (28,6±0,9) us on emission wavelength 600 nm for orange emitting por-Si is measured by the time resolved fluorescence. The behaviour of por-Si and grinded silicon (crystals of size about 1um) in biological environment (L929 mouse fibroblast) is studied with optical transmission microscopy, time-lapse microphotography of cell culture evolution, fluorescent microscopy, and scanning electron microscopy (SEM). Transmission pictures prove an aggregation in presence of por-Si in media. This aggregates are going to internal environment of cells. At high concentration of grinded silicon we see meronecrosis. Por-Si has had also mildly negative effect on evolution of cell culture at very high concentrations, but cells are viable and cell division proceeds normally - next cell generation shows normal behaviour. Fluorescence microscopy used on orange emitting por-Si shows that por-Si is concentrated probably on cell membranes and its presence in internal cell environment is also proved. SEM proved...
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Multicultural Education from the Perspective of Students of Secondary Schools in South Bohemian Region
KAŠPÁRKOVÁ, Michaela
Today's society is characterized by its multicultural diversity. Within the European Union you can travel and work freely in other countries, the same is true on the other hand, when in the Czech Republic there are still more foreigners who are trying to find a new home. Because of the ever increasing cultural pluralism may arise conflicts that may arise from disparities and the unknown. It was one of the reasons why schools introduced multicultural education. This thesis is called "Multicultural Education from the Perspective of Students of Secondary Schools in South Bohemian Region" and is divided into two parts. The first is the theoretical and the second part is practical. The theoretical part discusses the basic concepts of multicultural education such as the multiculturalism, ethnic group, nation, race, prejudice, etc., without which it would be difficult to orient in the area of multicultural education. The second half of the theoretical part deals with multicultural education in Czech schools, where the emphasis is on the curricula of multicultural education which came with us, talking about what should a teacher be, who is trying to implement multicultural education, etc. The practical section discusses the stated objectives of work and mentions the methodology used in the research and describes the research file. In the practical part it presents the results of the data obtained. This work has established two goals and two research questions. The aim of this study was to determine whether and how it is implemented multicultural education in secondary schools in South Bohemia and the second objective was to determine the attitudes and knowledge of students in the first and fourth years of school with the issue of multiculturalism in our country and the world. To achieve the objectives of qualitative the research was used in which eighteen semi-structured interviews with teachers who work at eleven secondary schools in South Bohemia were carried out. Interview questions were divided into four categories for better evaluation. To achieve the second objective it was compiled the questionnaire with mainly open-ended questions which were designed for students of the first and fourth years of four year schools. The questionnaire was completed so that the data could then be used to evaluate 130 first-year students and 130 fourth grade students on eleven secondary schools in South Bohemia. The results of interviews showed that to implement the education is not an easy task even though all respondents try to fulfill the Framework educational program for secondary school, which says that multicultural education should go throughout all the subjects. Teachers in the implementation of this education face difficulties. In most cases respondents, who teach social science, agreed that they have lack of time for teaching. This is precisely this subject in which multicultural education is crucial and should be implemented. Another problem is that teachers at all or poorly attend courses related to this cross-cutting theme. It is precisely at these seminars where the teachers can draw ideas on how to incorporate multicultural education into their lessons. Also they could obtain guidance documents, which all respondents are missing, at these seminars and perhaps this is the reason why multicultural education is little integrated. The results of the questionnaires helped to clarify that multicultural education is beneficial, at least in terms of knowledge and awareness of students with this issue. The fourth grade students in this area are more familiar and have larger insight than the first-year students. In the area of attitudes minor differences are seen when students of the first and fourth grades in most cases correspond to different views and attitudes.
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The secreted aspartic proteases of Candida parapsilosis.
Marečková, Lucie ; Dostál, Jiří (advisor) ; Novotný, Marian (referee)
Candida parapsilosis is an opportunistic fungal pathogen of humans causing a variety of infections. Immunocompromised individuals represent the most threatened group of patients. The increasing frequency of infections and occurrence of drug resistant strains are the main reasons for research focused on novel antimycotic compounds. Inhibition of secreted aspartic proteases (Sap) of pathogenic Candida spp. appears to be a potential target of therapeutic intervention. The genome of C. parapsilosis contains at least three genes coding for secreted aspartic proteases, denominated SAPP1-3. Protease Sapp1p has been well biochemically and structurally characterized, whereas Sapp2p and Sapp3p have been given less attention. The first part of the thesis is focused on structural analysis of Sapp1p complexes with selected peptidomimetic inhibitors binding to the active site of the enzyme. In addition, complex of the isoenzyme Sapp2p with the well-known secreted aspartate inhibitor Pepstatin A has been analyzed. The second part is related to the fact that C. parapsilosis belongs to the Candida spp. with the unique ability to translate standard leucine CUG codon mostly as serine. Even though it is a non-conservative substitution of hydrophobic amino acids for a hydrophilic one, this unique ability is maintained for more...
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Interactions of microscopic fungi and testate amoebae in Norway spruce litter
Konvalinková, Tereza ; Koukol, Ondřej (advisor) ; Nováková, Alena (referee)
Both testate amoebae and fungi are common inhabitants of coniferous litter. Their interactions in this environment were rarely studied, although they reach high biodiversity and can play a significant role in nutrient cycling in this environment. In this study, a cultivation of litter needles in the damp chambers was used to investigate interactions between fungi and testate amoebae. Observation of spruce litter needles in environmental scanning electron microscope was used to better characterize testate amoebae communities directly on the needles. Additionally, two experiments changing the biotic conditions in the microcosm were used to follow a principle of the interactions. Three species of testate amoebae from litter needles were able to colonize the filter paper on the bottom of the damp chambers. Occurrence of Phryganella acropodia and Assulina muscorum on the filter paper was significantly fuelled by the presence of mycelium. Assulina muscorum was associated with the fungal spores and Arcella discoides was attracted by sporulating colonies of Cladosporium spp. in the damp chambers. By contrast, no association of putatively mycophagous Phryganella acropodia with fungal spores was observed. Arcella discoides was attracted both by live and death mycelium in additional experiment. Interestingly, the...
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Alternative dispute resolutions in trade relations
Štávorská, Zuzana ; Kotoučová, Jiřina (advisor) ; Švarc, Zbyněk (referee)
This thesis discusses the alternative dispute resolution methods in trade relations. The main objective of this thesis is to describe and analyze ADR as a group of methods used to resolute disputes with focus on two main methods - mediation and arbitration. My objective is to describe the main principles of ADR, to compare their main advantages and disadvantages and to analyse the process of resoluting disputes by these methods. Another objective is to evaluate and analyze the development of ADR in the Czech Republic, their legal regulation and its current status. A short part of the thesis concerns about regulation of mediation in the EU and the analysis of implementation of the European Parliament and Council Directive 2008/52/EC dated May 21, 2008 to national legislation. Thesis is divided into five separate chapters. The first, introductory chapter only briefly discusses about dispute and conflict and ways they can be solved. The second chapter already characterizes ADR as a group methods of dispute resolution, its main principles, advantages and disadvantages and finally briefly describes some of the ADR. The third and fourth chapter focuses on the mediation, its principles, advantages, disadvantages, the mediation process and mediator. It monitors the development of mediation in the Czech republic and the current situation in the legal regulation of mediation in the country. The last chapter deals with arbitration. It describes its basic principles, advantages and disadvantages again. The conclusion discusses the czech Arbitration law and the forthcoming amendment.
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