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Contrast agents for hereronuclear MRI
Koucký, Filip ; Kotek, Jan (advisor) ; Havlík, Jan (referee)
In this thesis the pH dependency of the coordination modes of lanthanide complexes with macrocyclic ligands based on 1,4,7,10-tetraazacyclododecane skeleton was studied. The cyclen-based ligand structures in this work contained three acetate and one aminoethyl group with a N-alkyl-N-methylphosphonate substituent, DO3AN(R)P, where R is an alkyle substituent on the nitrogen atom of the pendant arm (R = methyl, benzyl). Lanthanide complexes of a previously studied prototype ligand DO3ANP with secondary amino group (R = H) have shown interesting properties in the field of 31 P NMR imaging because of their various coordination properties, which allow in situ pH measurement. These complexes can also be used for monitoring the kinetics of the chemical exchange of the amino group proton in 1 H NMR imaging using the chemical exchange saturation transfer (CEST NMR). In this thesis, two new derivatives DO3ANMeP and DO3ANBnP were prepared in order to better understand the coordination modes changes in this ligand series. Also, their coordination behaviour with selected lanthanide ions was studied (Eu3+ , Gd3+ , Dy3+ , Yb3+ ). Based on a series of NMR and luminescence measurements, it was found out, that in acidic conditions the complexes containing DO3ANP motif bind a water molecule in their coordination...
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Design and synthesis of surface architectures on fluorescent nanodiamonds
Havlík, Jan ; Kotek, Jan (advisor) ; Lang, Kamil (referee) ; Štěpánek, František (referee)
anks to their unique properties and high biocompatibilities, fluorescent nanodiamonds are promising representatives of modern carbon nanomaterials with a broad range of applications. Nevertheless, their wider use is limited because of weak fluorescence intensity and low colloidal stability in the biological environment. e optimization of treatment procedures and development of new suitable surface designs is therefore critically needed. In this study, several key steps for fluorescent nanodiamond treatment have been optimized, leading to both a substantial increase in fluorescence intensity and to significantly lower surface damage caused by graphitization. Further, a new high-throughput irradiation technique was developed. e influence of surface chemistry on the fluorescence parameters was studied using partial fluorination of the functional groups on the nanodiamond surface. A novel method which significantly affects the interaction of nanodiamonds with biological systems by increasing of the homogeneity and circularity was developed. e potential of nanodiamonds for future medical and biological research was demonstrated on particles with complex surface architectures that enabled targeting and therapy of tumor cells. Moreover, a strong and highly selective affinity of fibroblast growth factors to diamond...
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Advanced numerical simulations in space plasma physics using Finite Element Method
Kotek, Jan ; Bárta, Miroslav (advisor) ; Varady, Michal (referee)
en.txt After an introduction into current sheet physics, with emphasis to solar physics we showed some formulations of finite element method. We implemented and evaluated new discontinuous finite element with Taylor basis and introduced deal.II library with an example of burgers equation. While the program is dimension independent, we compared our solution with a one-dimensional analytical solution. Finally, using previously derived LSFEM formulation, we solved simple current sheet problem using deal.II. Stránka 1
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Selective complexation of transition metals ions
Beliš, Marek ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
Copper radionuclides possess physical properties suitable for utilization in nuclear medicine. Important part of their preparation is separation from mother elements, usually zinc or nickel. Currently used methods of separation have their limits, what opens field for finding new ways. One part of the Thesis contains preparation of simple ion exchangers and their selectivity study. The other part of the Thesis is dedicated to optimization of synthetic steps leading to new bifunctional ligands in suitable form for binding to macromolecular carriers and preparation of new set of exchangers.
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Ligand design for medicinal applications
Paúrová, Monika ; Kotek, Jan (advisor) ; Trávníček, Zdeněk (referee) ; Řezanka, Pavel (referee)
In recent years, copper radioisotopes have been extensively studied for their suitable coordination and physical properties. Nuclides 61 Cu, 64 Cu and 67 Cu are used in nuclear medicine - in diagnostic as well as in therapeutic applications. The aim of the Thesis is a study of the coordination properties of divalent copper as a stepping stone for the next potential applications. The presented Thesis consists of two thematic parts. The first part deals with the synthesis of cyclam derivatives. Sixteen new macrocyclic ligands with different phosphorus acid coordinating pendant arms (phosphinate, phosphonate, germinal P-C-P) were prepared; an analogous ligand endowed by carboxylic acid pendant arm as well as tetramethylcyclam without coordinating arm were prepared for comparison. The influence of the nature of coordinating acid pendant arms on selectivity and on the rate of copper(II) complexation was studied in detail. The protonation constants of the free ligands and the stability constants of the complexes with selected transition metal ions were determined by potentiometric titrations and by 1 H and 31 P NMR spectroscopy. Kinetic properties - i.e. studies of the formation rate and kinetic inertness of the copper(II) complexes - were performed by UV-Vis spectroscopy. The formation kinetics of the selected...
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