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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.
71

Drobné prachové částice v plynných produktech spalování / Flue gases aerosol

Chobot, Ivan January 2012 (has links)
Goal of this dissertation is introduce the problem of small dust particles present in the gaseous products of combustion. Further I´m looking technologies cyclone and an electrostatic filter to capture small particles and comparing the effectiveness of separability. Dissertation is concluded by designed cyclone and an electrostatic filter.
72

Polymerní materiály pro řízenou administraci léčiv a řízené uvolňování aktivních látek / Polymeric Materials for the Controlled Drug Delivery and Controlled Release of Active Substances

Chamradová, Ivana January 2015 (has links)
Literární rešerše předložené dizertační práce shrnuje poznatky jak o současně používaných biomateriálech, tak i o tzv. „chytrých“ biomedicínských materiálech mezi které patří termocitlivé kopolymery. Mezi tyto kopolymery, jejichž vodné roztoky gelují při teplotě lidského těla (37 °C), řadíme amfifilní triblokové kopolymery skládající se z hydrofobního laktidu, glykolidu a hydrofilního polyethylen glykolu (PLGA PEG PLGA). Komerčně dostupné termocitlivé kopolymery známé pod názvem ReGel or OncoGel jsou v současné době využívány jako injekčně aplikovatelné nosiče s postupným uvolňováním léčiv, zejména při léčbě cukrovky nebo onkologického onemocnění. Nicméně PLGA PEG PLGA triblokový kopolymer může být použit I jako polymerní nosič anorganického léčiva případně jako biodegradabilní implantát v dentálních či ortopedickýchých aplikacích. Z toho důvodu byl vybrán anorganický biokompatibilní hydroxyapatit (HAp) pro své majoritní zastoupení v tvrdých tkáních. Experimentální část je zaměřena na přípravu HAp/PLGA PEG PLGA kompozitů, ve kterých je HAp buď ve formě nano- (n-HAp) nebo „core-shell“ částic (CS). Nové CS částice, připravené dvouemulzní metodou, jsou složeny z „tuhého“ HAp jádra obaleného termocitlivým kopolymerem, který je navíc funkcionalizován kyselinou itakonovou (ITA/PLGA PEG PLGA/ITA). Funkcionalizace pomocí ITA vnáší do původní struktury kopolymeru jak síťovatelné dvojné vazby, tak i koncové karboxylové skupiny. Volné karboxylové skupiny na koncích ITA/PLGA PEG PLGA/ITA kopolymerního obalu byly dále zesíťovány za vzniku 3D chemické sítě (CS-x), jejíž životnost je řízena a kontrolována. ATR-FTIR spektroskopie prokázala přítomnost „nových“ esterových vazeb vzniklých karbodiimidovou reakcí –OH a –COOH skupin, kterým náleží adsorpční pásy ve vlnové délce 1021 cm-1.. n-HAp a CS-x částice byly přidány do kopolymerní termocitlivé matrice (PLGA PEG PLGA) za účelem charakterizace jejich reologického chování. Bylo zjištěno, že pokud bylo do polymerní matrice přidáno méně než 10 hm. % CS-x částic a jen 5 hm.% n-HAp kompozit si zachoval své termocitlivé vlastnosti. Na druhou stranu, přídavek vyššího množství HAp částic do polymerní matrice zajistil změnu vodného polymerního solu v permanentní gel při teplotě nad 37 °C. Analýza ICP-OES prokázala rychlejší uvolňování CS-x částic z 10 hm/obj. % PLGA PEG PLGA polymerní matrice do inkubačního média (6 % 9. den) než tomu bylo u n-HAp částic (jen 3 %), které jsou vázány více v micelární struktuře kopolymeru. Proto, kompozit na bázi n-HAP částic tvořící tuhý trvalý gel při tělesné teplotě, je vhodný více jako biologicky rozložitelné kostní lepidlo, zatímco kompozit z CS-x částic a termocitlivého kopolymeru je vhodný jako nosič léčiv pro injekční aplikace.
73

Posouzení koncepce nového řešení kluzného kontaktu v elektrických strojích / Assessment of the design of the new solution sliding contact in electrical machines

Záhejský, Petr January 2016 (has links)
The thesis is devoted to assessing the concept of a new solution to the sliding contact in electrical machines. The work is focused mainly on the issue of collector engines, which are almost exclusively used in electric hand tools. Much of the work is devoted to angle grinders, which are usually used in extreme conditions and demands for seamless operation are enormous. In order partial insight into the problems in the introduction are studied phenomena acting on the sliding contact, wear and durability. Then further materials and diagnostic methods for increasing the transfer efficiency brush - commutator brush - ring. The following sections of this thesis is also considered a proposal innovated brush along with the practical verification and evaluation of the suitability of the use of innovative sliding contact.
74

Využití magnetických nano- a mikro částic při izolaci DNA z vybraných druhů potravin / The application of magnetic nano- and microparticles for the isolation of DNA from selected foods

Ráčková, Lucie January 2017 (has links)
In thesis was verified micromethod for isolation of plant DNA from different vegetable (onion and broccoli) and plant food products in quality for application in polymerase chain reaction (PCR). The micromethod allows isolation DNA using magnetic particles from crude lysates of cells obtained by direct homogenization of plant tissues. Various methods of processing homogenates were compared. Homogenization was performed by lysis buffer containing cetyltrimethylammonium bromide (CTAB). The effect of the organic extraction agents was tested (chloroform-octanol and isopropanol). DNA was purified from homogenates by reversible adsorption on magnetic particles (four different types of magnetic particles were tested). The quality of isolated DNA was verified by UV spectrophotometry. The amplificabilty of DNA was tested by polymerase chain reaction (PCR). Specific primers for plant ribosomal DNA (rDNA) were used. PCR products of lenght 700 and 220 bp were detected by agarose gel electrophoresis. Differences in yield and quality of DNA were depended on the homogenate processing and magnetic particles used. The proposed procedure with two magnetic particles was tested for the isolation DNA from plan food products (spreads). DNA was amplified in PCR. Micromethod is suitable for DNA analysis of foods.
75

Využití technik enkapsulace k přípravě výrobků určených pro dětskou výživu / Use of encapsulation techniques for production of food for infants

Hoová, Julie January 2017 (has links)
The Diploma thesis deals with use of selected probiotic strains Lactobacillus acidophilus and Bifidobacterium breve in different forms in food for infants. The theoretical part is focused on describing probiotics, encapsulation methods and intestinal gut microbiota of infants. Further, characterization of individual periods of infant feeding and food for infants were introduced. In experimental part the possibilities of encapsulation and lyophilisation of probiotic cells were observed. Probiotic cells were encapsulated into alginate particles. The encapsulator was used for preparation of particles and the most appropriate particles were prepared by encapsulation nozzle with size of 300 µm. Moreover, probiotics viability was monitored by Flow Cytometry, Fluorescence Microscopy and by cultivation (CFU method). Viability of probiotics was monitored during long-term storage in selected food for infants. The appropriate shelf life of non-lyophilized alginate particles in real food have been set at 1 to 2 months. Lyophilized alginate particles could be stored for more than 3 months. Finally, the stability of the particles and viability of encapsulated and non-encapsulated cells in the gastrointestinal tract conditions were also examined. The viabilities of lyophilized cells and cells encapsulated in lyophilized particles were also compared. From the results obtained, non-encapsulated probiotic bacteria cells are more susceptible to negative effects of digestive juices, the percentage of dead probiotic cells after digestion was approximately 80 %. On the other hand, alginate particles showed cell protection from digestive juices, after incomplete cell releasing from particles the percentage of dead probiotic cells did not exceed 20 %. After adequate rehydration, similar results were gained with lyophilized alginate particles. Lyophilized alginate particles have been determined to be the most suitable application form for infants’ food.
76

Heterologní exprese onkoproteinu E7 lidského papilomaviru (HVP 16) / Heterologous expression of the E7 oncoprotein from human papillomavirus HVP16

Lidický, Ondřej January 2010 (has links)
Production of vaccines and pharmaceutical proteins in plants is a promising nascent technology with a great potential to provide high-quality, safe and non-expensive production and delivery platform. In this work we studied the experimental vaccine against human papillomavirus based on modified plant pathogen - Potato virus X (PVX). The experimental vaccine is based on PVX virus particles decorated with genetically fused HPV-E7 oncoprotein. These chimeric virus particles should be able to activate strong and specific cellular immune response. However the modification of the PVX coat protein with such relatively large fused protein might influence its ability to form particles. In this work we have characterized some properties of such chimeric virus particles like solubility or ability infect host plant. (In Czech)
77

Analýza protilátkové odpovědi u BK virové infekce / Analysis of antibody response during BK virus infection

Tomanová, Tereza January 2019 (has links)
BK virus is a human polyomavirus which is highly prevalent in the population. The virus is usually not very dangerous to its host, but it may cause complicati- ons in immunosuppressed patients. These complications commonly appear after kidney transplantation because BK virus persists in kidney epithelial cells. There are four subtypes of BK virus and it might be clinically important to screen for the identity of subtypes in matched pairs of donors and recipients of the kidney. This determination of the subtype specific antibodies by simple test could help to manage complications after the surgery. During previous project the ELISA test that could serologically differentiate between two main BK virus subtypes (I and IV) was designed, but its development is complicated by the fact that there is a strong cross-reactivity between the BK virus subtypes and antibodies. The modification of antigen towards better specificity might be required to succeed. Consequently, the main aim of this diploma thesis was to map important spots of major capsid protein VP1 of BK virus, particulary in EF and DE loops, which could participate in binding of antibodies. This aim was addressed by targeted mutagenesis of the gene coding VP1 protein in the region of the respective loop. Nucleotides coding two surface aminoacids...
78

Měření a toxicita nanočástic ze spalovacích procesů / Measurement and toxicity of combustion generated nanoparticles

Sikorová, Jitka January 2020 (has links)
This thesis is focused on nanoparticles produced by internal combustion engines utilized in vehicles. It deals with spatial distribution of nanoparticles within urban areas, impact of alternative fuels usage on particle production and toxicity, and a particle toxicological testing methodology. Monitoring of airborne nanoparticles identified traffic as the main source of airborne nanoparticles in places with heavy traffic load (Prague), as well as in a small city with only local traffic (Čelákovice). Most particles were likely emitted during short episodes of high emissions (e.g. uphill acceleration). During the measurements, high-emission vehicles responsible for a large fraction of the air pollution were also identified. On the other hand, small non-road internal combustion engines, which are not subject to any limit on particle emissions, such as a lawn mower, were operated during the measurement and generated a large number of nanoparticles. The amount and characteristics of the particles produced by combustion depend on the combustion technology and the fuel composition. A large part of the thesis deals with alternative fuels and their effects on the quantity of produced particles and toxicity of organic matter adsorbed on the particles. Hydrotreated vegetable oil (HVO) exhibited the lowest...
79

Peptidové inhibitory imobilizované na magnetické nosiče a Sepharosu aplikované na separaci žaludečních aspartátových proteinas / Peptide inhibitors immobilized on magnetic particles and Sepharose used for separation of stomach aspartate proteinases

Rajčanová, Michaela January 2014 (has links)
IN ENGLISH Human gastric juice contains mainly aspartate proteinases: pepsin A and pepsin C. Both pepsins are produced by gastric mucosa as inactive pepsinogens and they are activated to the corresponding pepsins in the acidic environment of the gastric lumen. The levels of pepsinogens in serum reflect the morphological and functional status of gastric mucosa. A subject of this thesis is a part of a long-term investigation that focuses on the elaboration of methods for separation gastric aspartate proteainases that would be suitable for diagnostic purposes. The preparation of new type ligands was a concrete subject of PhD. thesis that after their immobilization they can enable the separation of aspartate proteinases. Four heptapeptides containing D-leucinyl residue were synthetized (Val-D-Leu-Pro-Phe-Phe-Val- D-Leu, Val-D-Leu-Pro-Tyr-Phe-Val-D-Leu, Val-D-Leu-Pro-Tyr-Tyr-Val-D-Leu and Val-D- Leu-Pro-Phe-Tyr-Val-D-Leu. The prepared heptapeptides immobilized on agarose magnetic particles were used for the study of their interaction with porcine pepsin A and rat pepsin C. While porcine pepsin A was adsorbed to all heptapeptides immobilized to magnetic particles, rat pepsin C was not retarded. Similar results were obtained using heptapeptides immobilized to Sepharose. The situation was more complicated...
80

Rychlá separace výbušnin vysokoúčinnou kapalinovou chromatografií / Fast separation of explosives by high performance liquid chromatography

Šesták, Jozef January 2011 (has links)
The topic of the diploma thesis is fast separation of explosives by HPLC and development of miniaturized liquid chromatograph for application in a handheld explosives detection device. In this work the retention of some nitrated explosives and selectivity in reversed phase system as a function of mobile phase composition is studied while methanol, acetonitrile and acetone as an organic solvent is used. Best selectivity and good retention can be observed in methanol mobile phase. Acetonitrile and acetone are not suitable for fast isocratic separation of mixture containing pentaerythritol tetranitrate because of its strong retention. Efficiency and permeability of monolithic column (Chromolith CapRod RP-18e) and columns filled with superficially porous particles are compared (Kinetex 2,6 µm C-18, Poroshell 120 SB-C18). Monolithic column with satisfying efficiency and high column permeability is the most suitable solution for fast separation of explosives. Assuming use of explosives detection device in different conditions the separation was optimized on temperature 50 °C. Under these conditions the 35% v/v methanol gives good retention and selectivity. For very fast scan analysis of pentaerythritol tetranitrate or other nitroaromatics use of 70% v/v acetone mobile phase is suitable. Construction of miniaturized liquid chromatograph that enables preconcentration of explosives from aqueous solutions and fast separation in less than 1 minute is described. This concept will be incorporated into the handheld explosives detection device where the explosives vapor will be absorbed into the water and after the separation detected by chemiluminescence.

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