|
|
Substrátem kontrolované fyzikální vlastnosti tenkých vrstev magnetických oxidů pro spintronické aplikace
Maleček, Tomáš ; Veis, Martin (advisor)
As conventional electronics approaches its fundamental limits, new paradigms are re- quired. Integration of new spintronic materials with current silicon technology shows great promise. This thesis demonstrates the possibility of growing textured stress-free La2/3Sr1/3MnO3 (LSMO) thin films on silicon with properties comparable to epitaxi- ally grown layers on SrTiO3 (STO). Growth of LSMO is achieved by a two-dimensional nanosheet (NS) seed layer of Ca2Nb3O10 inducing epitaxial stabilization of LSMO films. Samples of LSMO on NS/Si, prepared by pulsed laser deposition, have been shown to have lower magnetization than samples of LSMO on STO yet also possess a higher Curie temperature by more than 10 K. Spectral dependence of the full permittivity tensor was calculated from optical and magneto-optical measurements. Spectra of the off-diagonal element have been fitted with three diamagnetic transitions located around 1.9, 2.9 and 3.5 eV for samples on NS/Si as well as for samples on STO. Similarities between the samples open the possibility of integration of LSMO into silicon technology using NS. Temperature-dependent optical and magneto-optical properties of a sample of LSMO on STO have been evaluated.
|
|
|
Mercury in soils from mining and smelting districts in Zambia and Namibia
Podolský, Filip ; Ettler, Vojtěch (advisor) ; Vaňková, Maria (referee)
This master thesis is a part of project IGCP No. 594: "Assessment of Impact of Mining and Mineral Processing on the Environment and Human Health in Africa" and its goal is to determine and compare mercury content in 91 soil samples from mining and smelting areas in northern Namibia and 68 soil samples from the Copperbelt province in Zambia. Highest mercury concentrations in soils (with maximum 4.39 mg Hg kg-1 ) were found near the Tsumeb copper smelter in Namibia, whereas Hg concentrations were significantly lower in the Zambian Copperbelt (up to 0.392 mg Hg kg-1 ). Decreasing concentration of contamination corresponding to distance from the source of pollution has been confirmed at both localities. For an estimation of a possible source of contamination, 26 samples from smelting processes and waste were also taken. Highest concentrations of Hg were observed in Tsumeb again (219 mg Hg kg-1 in bag- house residue and 3,5 mg Hg kg-1 in processing wastes on tailing dams). Studies of mercury mobility in soil profile by correlation coefficients has shown Hg dependent on the content of sulfur and organic carbon, which indicates a dependence on the content of organic matter. Among metals and metalloids best correlations between Hg and Cu, As, Sb, Pb, and Zn were calculated. Because mercury is currently...
|
|
|
Development of surface and body musculature of the bird schistosome Trichobilharzia regenti
Bulantová, Jana ; Horák, Petr (advisor) ; Nebesářová, Jana (referee) ; Toledo, Rafael (referee)
Description of Trichobilharzia regenti as a new species of nasal bird schistosome in 1998 was only the first step in our knowledge of this extraordinary parasite. Natural definitive hosts of T. regeni are anseriform birds, but infective larvae - cercariae - are able to penetrate also into mammalian hosts including humans. There they are causative agents of hypersensitive skin immune reaction called cercarial dermatitis or swimmer's itch. Contrary to other schistosomes, miracidia of T. regenti hatch directly inside the definitive host tissue. Schistosomula migrate through the nervous system of vertebrates and, together with adult worms, they have predominantly extravascular localization in definitive hosts. Adult worms have a short lifespan and low degree of sexual dimorphism, connected with lower dependence of adult females on long-term contact with males. During the life cycle, T. regenti can be found within three different environments (freshwater, tissue of intermediate molluscan host and tissue of vertebrate host). Each of the seven developmental stages has a different role in the life cycle which corresponds with different organization of various organ systems. The introductory part of the thesis is focused entirely on ontogenetic changes of surface ultrastructure and body musculature of...
|
|
|
Synthesis of Tetrahydroacridine Inhibitors of Acetylcholinesterase
Korábečný, Jan ; Opletalová, Veronika (advisor) ; Vinšová, Jarmila (referee) ; Mičuda, Stanislav (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Candidate Mgr. Jan Korábečný Supervisor Assoc. prof. RNDr. Veronika Opletalová, Ph. D. Title of Doctoral Thesis Synthesis of tetrahydroacridine inhibitors of acetylcholinesterase Cholinesterase inhibitors have beneficial effects on cognitive, functional, and behavioural symptoms of Alzheimer's disease (AD). Up to date, they represent the only drugs approved by U.S: Food and Drug Administration for AD treatment. These include donepezil, rivastigmine and galantamine. Apart from the above mentioned cholinesterase inhibitors memantine is used for AD treatment as well, acting as N methyl- D-aspartate antagonist drug. Tacrine (9-amino-1,2,3,4-tetrahydroacridine) was the first cholinesterase inhibitor to obtain a marketing authorisation in symptomatic treatment of AD. However, its several side effects (hepatotoxicity and gastrointestinal discomfort) limited tacrine broader usage. Novel tacrine derivatives are extensively investigated in endeavour to find less toxic compounds with "multi-target directed ligand" profile affecting more pathological mechanisms. As a part of these research efforts, 7-methoxytacrine (7-MEOTA) has been prepared as a less toxic derivate compared to tacrine...
|
|
|
Potential contrast agents for MRI based on manganese(II) complexes
Drahoš, Bohuslav ; Lukeš, Ivan (advisor) ; Geraldes, Carlos F. G. C. (referee) ; Toth, Imre (referee)
The thesis is focused on the synthesis and characterization of novel Mn2+ complexes as alternative to Gd3+ chelates which are wide-spread contrast agents in Magnetic Resonance Imaging (MRI). In the perspective to find suitable chelators of Mn2+ , three groups of pentadentate ligands with different size of macrocylic cavity, different donor atoms and number of pendant arms containing various functional groups have been investigated. Coordination numbers of 6 or 7 were found in the crystal structure of the Mn2+ complexes enabling binding of one or two water molecules in the first coordination sphere. The direct water coordination causes a decrease in the complex stability and thus, the thermodynamic stability of investigated chelates is lower than that of polyaminocarboxylate complexes and their dissociation is very fast in comparison to [Mn(nota)] and [Mn(dota)]2- . The studied Mn2+ complexes do not undergo oxidation in air except for complexes with 12-membered ligands which are oxidized to Mn3+ species. The proton relaxivities of the bishydrated complexes are two times higher than those for monohydrated complexes and are comparable to those of commercial contrast agents based on Gd3+ complexes. Variable-temperature 17 O NMR data revealed that the water exchange varies from slow to intermediate or...
|
|
|
Stability and efficiency of a new Mn-oxide based sorbent in contrasting soils
Knytl, Vladislav ; Ettler, Vojtěch (advisor) ; Komárek, Michael (referee)
Metal contamination of soils is one of the most important environmental problems throughout the world. One of the possible remediation technique of contaminated soils is based on chemical stabilization using various amendments. Due to their structure and sorption properties (pHZPC, specific surface, CEC etc.), Fe, Mn and Al oxides are suitable for this remediation technique. The focus of this diploma thesis is to evaluate the stability and the effectivity of the new synthetic amorphous Mn oxide (AOM) in soil samples with contrasting physicochemical parameters, mainly pH: soil N (pH 4,2), soil H (pH 5,4), soil S (pH 7,3). In a 90-day laboratory pot experiment with incubation of AMO in these soils we found that stability of AOM is strictly pH-dependent. Higher dissolution was observed in the most acidic soil N (mass loss up to 18%), whereas in alkaline soil S themass loss attained only 10%. The dissolution of AOM in acidic soils (N, H) was connected with a significant release of Mn into the soil pore water. For soils H and S the massive formation of secondary carbonate phases (rodochrozite - MnCO3, kutnahorite - (Ca,Mn)CO3) was detected on the AOM surfaces by X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Granulometric measurements...
|
|
|
Study of new acetylcholinesterase modulators
Račáková, Veronika ; Opletalová, Veronika (advisor) ; Pohanka, Miroslav (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Candidate: Mgr. Veronika Račáková Consultant: Assoc. Prof. RNDr. Veronika Opletalová, Ph.D. Title of Thesis: Study of new acetylcholinesterase modulators. Organophosphorus compounds are chemically organophosphates or organophosphonates. They have been widely used as a pesticides but because of their high toxicity and relatively cheap and easy synthesis they can be easily misused as chemical weapons - nerve paralytic compounds. Toxic effect of these compounds is based on irreversible inhibition of the enzyme acetylcholinesterase (AChE). In case of intoxication by these compounds anticholinergic drugs (atropin) and reactivators of AChE are usually used as antidots. The effect of the reactivators is based on splitting the complex enzyme-inhibitor. Pralidoxim, trimedoxim, obidoxim and asoxim (HI-6) are still the most often used reactivators all over the world. They are the compounds which contain oxime group and one or two quarternary nitrogens in their molecule, what ensures that their affinity to AChE will be strong enough. Screening and synthesis of new more effective broad-spectrum reactivators of AChE with lower side effects is still very actual and discussed theme. Strategy...
|
|
|
Applications of capillary electrophoresis in life sciences
Křížek, Tomáš ; Coufal, Pavel (advisor) ; Pacáková, Věra (referee) ; Tůma, Petr (referee)
Tomáš Křížek: Applications of Capillary Electrophoresis in Life Sciences (Dissertation thesis) ABSTRACT This thesis is focused on the applications of capillary electrophoresis in two important areas of life sciences, proteomics and enzyme assays. In the first part, Pluronic F-127 copolymer was studied as a sieving matrix for proteomic applications of capillary gel electrophoresis. The effect of thermoassociation of Pluronic F-127 on the separation selectivity was investigated and no difference in selectivity of the separation below, inside and above the thermoassociation temperature region was observed. The performance of Pluronic F-127 in capillary gel electrophoresis was compared with dextran as a commonly used sieving matrix. The results showed, that Pluronic F-127 offers superior performance for low-molecular-mass proteins because it provides higher separation power than dextran with significantly lower viscosity of the background electrolyte. The lower viscosity makes the polymer easier to replace after each analysis, which leads to remarkably higher repeatability of the experiments. On the other hand, dextran, due to its higher viscosity, was shown to be more convenient for separations of protein digests, where extremely high separation efficiency is required. The second part focuses on...
|
|
|
Self perception, body image and quality of life in overweight and obesity children aged ten to twelve
Antelmanová, Kateřina ; Hrachovinová, Tamara (advisor) ; Šírová, Eva (referee)
The thesis deal with self -perception, body image and quality of life of children suffering from overweight and obesity. The age of children ranges from 10 to 12. In theoretical part thesis deals with definition of the children obesity. The research is of quantitative character and uses several questionnaire methods. For self-perception has been chosen Self-perception profile for children inventory, for quality of life Pediatric quality of life inventory and for Body image Child Figure Scale. The dates were obtained in primary schools, health resorts and sanatorium all over the Czech Republic. In the research participated 211 children (117 girls and 94 boys). On the basis of percentile BMI the children were divided into clinical (N=50) and nonclinical (N=161). We statistically have analysed questionnaire results and we have done the comparison between clinical and nonclinical group. It has been ascertained that the children who suffer from overweight and obesity achieve in all the tests lower average scores than the children with the normal weight. Self-perception, body image and quality of life of children with overweight and obesity is lower than children with the normal weight. On the contrary, the assumption was not confirmed that the girls from a clinical group are more dissatisfied with their...
|
|
|
The potential of aldo-keto reductase 1C3 inhibition as an off-target effect of isocitrate dehydrogenase 2 inhibitor enasidenib in leukemia.
Haddad, Melodie ; Wsól, Vladimír (advisor) ; Macháček, Miloslav (referee)
Univerzita Karlova, Farmaceutická fakulta v Hradci Králové Katedra biochemických věd Kandidát: Melodie Haddad Školitel: Mgr: Ing. Vladimír Wsól, Ph.D. Konzultant: Anselm Morell García, Ph.D. Název diplomové práce: POTENCIÁL INHIBICE ALDO-KETO REDUKTÁZY 1C3 JAKO NECÍLENÉHO ÚČINKU INHIBITORU ISOCITRÁT DEHYDROGENÁZY 2 ENASIDENIBU U LEUKÉMIE Akutní myeloidní leukémie (AML) zahrnuje nadměrnou proliferaci klonálních myeloidních blastů. Studuje se několik léků zaměřených na mutace AML, přičemž enasidenib (ENA) je prvním selektivním inhibitorem mutací izocitrát dehydrogenázy 2 (IDH2) schváleným úřadem FDA. Současná multicentrická klinická studie ukázala povzbudivé výsledky kombinace ENA se standardní intenzivní indukční léčbou, včetně daunorubicinu (Daun). Exprese transportérů ABC (ATP-binding cassette) a aldo-keto reduktázy 1, člena C3 (AKR1C3) v buňkách AML však může vést k extruzi a hydroxylaci Daunu, což snižuje jeho cytotoxické účinky. Cílem této studie bylo zhodnotit vliv ENA na akumulaci a/nebo inaktivaci Daunu v leukemické buněčné linii KG1α. ENA měla synergický účinek na cytotoxicitu Daunu v buňkách KG1α v souvislosti s jeho vyšší akumulací a nižší metabolizací. Kromě toho AKR1C3 také katalyzuje přeměnu prostaglandinu D2 (PGD2) na 9α a 11β-prostaglandin F2α (11β-PGF2α), který indukuje proliferaci...
|
guest ::
