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Plasmid DNAs interactions with lanthanoide compounds
Budko, Kateryna ; Horák, Daniel (referee) ; Rittich, Bohuslav (advisor)
Recently much attention is given to lanthanides and their complexes as excellent catalysts for cleavage of nucleic acids. The thesis has been focused on the cleavage of plasmid and bacterial DNA by ions Nd3+ and Y3+ and by different carriers containing the lanthanide compounds. The creation of single-stranded nicks and double-stranded ones in the plasmid DNA molecules was studied by agarose gel electrophoresis. Verification of the cleavage of bacterial DNA was made by polymerase chain reaction using primers specific for the domain Bacteria and genus and species-specific primers. The results will be used in the development of the method that will allow perfect carriers`s coverage verification with the magnetic perovskit nucleus and other carriers with the lanthanide compounds.
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Methods of insect body and food marking and their utilization in bees (Anthophila)
Macháčková, Lenka
Marking methods represent often an essential part of many studies which target on insect biology. These marking techniques sometimes represent the only possible way to obtain new and important informations. In the first part of the thesis I deal with individual insect labeling, which was used for marking of solitary bees and their nests as a tool of obtaining informations about nesting bee dynamics in aggregation. Our study show that nest owner replacements are very common in all four species. However, a large percentage of the nests were abandoned by the female owners before owner change. Only a part of all the nests were trully usurped on the nesting site. The true usurpations thus represent rather minor part of observed nest owner replacement situations. The bees surprisingly often abandon their nests and found the new ones. The frequent contacts of the females on a nesting site occur as a result of common nest owner replacements. High tolerance of bees to each other together with tolerance of usurpations and low level of aggression may thus represent one of the possible ways towards communality and other types of social behaviour. In the second part of the thesis I focus on the possibilities of food marking in bees. Effectivity of sugar and pollen utilization are not yet fully understood in...
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MRI contrast agents for modern applications
Kotková, Zuzana ; Hermann, Petr (advisor) ; Pinkas, Jiří (referee) ; Drahoš, Bohuslav (referee)
Zuzana Kotková - Ph.D. Thesis: MRI Contrast Agents for Modern Applications 1 Abstract Over the last few decades, Magnetic Resonance Imaging (MRI) has become one of the most powerful medicinal methods for the diagnosis of various diseases (Fig. A1a ). In several types of examinations, contrast agents (CAs) are used to increase the quality of images (Fig. A1b ). These contrast agents are usually based on paramagnetic metal complexes of macrocyclic ligands. In dependence on the measured nuclei, two basic groups of CAs are considered - 1 H MRI CAs and, recently, also 19 F "hot-spot" CAs. The 1 H MRI CAs are based on Gd3+ complexes of macrocyclic ligands with one water molecule coordinated to the central metal ion (Fig. A1c ) and the effect of the CAs is to shorten the relaxation times of water protons. (a) (b) (c) Fig. A1: Illustrative pictures for Magnetic Resonance Imaging (MRI) method; (a) whole body MRI tomograph,* (b) an example of MR head scans with the use of MRI CA** and (c) schematic general structure of a contrast agent based on Gd3+ complex of macrocyclic ligands (for more details see the Thesis, section 1.3.3, Fig. 18). * https://www.ottawaheart.ca/test-procedure/cardiac-mri (Accessed 25 Febr. 2023) ** https://affordablemri.com/mri-explained (Accessed 25 Febr. 2023) The shortening of relaxation...
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Bioakumulace vzácných kovů z červeného kalu
NÁHLÍK, Vít
This study deals with the bioaccumulation of scarce metals, especially lanthanides, contained in red mud. The effect of red mud is studied on cultures of La4 mutant of the green alga Desmodesmus quadricauda and on red microalga Galdieria sulphuraria under different metabolic regimes with the addition of acidic extract of red mud.
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Responsive Contrast Agents for Magnetic Resonance Imaging (MRI)
Krchová, Tereza ; Kotek, Jan (advisor) ; Marek, Radek (referee) ; Platas-Iglesias, Carlos (referee)
ABSTRACT This work is focused on the synthesis of a family of new macrocyclic ligands with exchangeable protons on coordinating groups that could potentially serve (after complexation with suitable paramagnetic lanthanide(III) ions) as responsive contrast agents (CAs) for magnetic resonance imaging (MRI). It is expected that measurement of extracellular pH should bring information for tumorous disease diagnoses and/or for suggesting the most efficient treatment. Therefore, our attention was focused on pH-dependent CAs based on a PARAmagnetic Chemical Exchange Saturation Transfer (PARACEST) mechanism capable of reporting pH changes in tissue. The PARACEST-related properties of a series of Ln(III) complexes with the CEST effect caused by amino groups coordinated to the central Ln(III) metal ions were investigated. Such a kind of PARACEST CA is new and has had no precedent in the literature. It was shown that these Ln(III) complexes produce a pH-sensitive PARACEST effect in the pH region relevant for living systems. The study brings proof-of-principle for utilization of complexes with a linear diamine pendant arm, i.e. complexes with two exchanging proton pools, for ratiometric pH determination by MRI independently on the probe concentration. In addition, to ensure a higher kinetic inertness of the...
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New ligands for applications in medicine
Holá, Kateřina ; Kotek, Jan (advisor) ; Holzhauser, Petr (referee)
The aim of this Thesis was the preparation of macrocyclic ligands (Figure 1) for the complexation of lantanoides 3+ . Their complexes can be used in nuclear medicine (in case of ligand L1) or as MRI contrast agents (in case of ligand L2). Ligand L1 was designed to increase the rate of complexation due to the weakly binding pendant group based on iminodiacetic acid (IDA). The complexation mechanism was spectrophotometrically studied with Ce3+ . Spectrophotometric kinetic measurements proved that ligand L1 not only shown no improvement in the complexation rate but its complexation is rather noticeable slowed. Ligand L2 contains amino group whose protonization/coordination could be influenced by pH or temperature. It can be utilized in determination of physical status of different tissues. However, it is difficult to obtain the ligand L2 in sufficient purity for further studies N N NN COOHHOOC HOOC N COOH COOH P OH O L1 N N NN COOHHOOC HOOC NH2 L2 Figure 1: Ligands prepared in course of this Bc Thesis
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Macrobicyclic ligands for use in MRI
Pniok, Miroslav ; Kotek, Jan (advisor) ; Veselý, Jan (referee)
4 Title: Macrobicyclic ligands for use in MRI Author: Bc. Miroslav Pniok Department: Department of Inorganic Chemistry, Faculty of Science Supervisor: doc. RNDr. Jan Kotek, Ph.D. Supervisor's e-mail address: modrej@natur.cuni.cz Abstract: The aim of this project is to synthesize new kind of macrobicyclic ligands for Ln3+ ions, especially Gd3+ ion. Gadolinium(III) complexes are widely used in the clinical practice as contrast agents for MR imaging and an improvement of their properties is in the center of interest of many scientific teams. The macrobicyclic ligands have been designed to make possible coordination of two water molecules in the first coordination sphere with fast water exchange. The macrocyclic core (cyclen) is combined with a linking phosphinate chain in N1 ,N4 - and N1 ,N7 -positions forming a cryptand-like structure. The N1 ,N7 -isomer Et2L1 was synthesized in a small amount so only the N1 ,N4 -isomer H2L3 has been studied. The protonation constants have been determined by pH 31 P NMR titration. Keywords: cyclen, chelating agent, cryptand, MRI, phosphinate
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New ligands for magnetic resonance imaging; pH-sensitive probes
Táborská, Zdeňka ; Kotek, Jan (advisor) ; Kubíček, Vojtěch (referee)
TÁBORSKÁ, Z. New ligands for magnetic resonance imaging; pH-sensitive probes. Prague: Charles University in Prague, Faculty of Science, Department of Inorganic Chemistry, 2011, 32 pages. Supervisor: doc. RNDr. Kotek J., Ph.D. Magnetic resonance imaging is a modern method used in diagnostic for assessing morphology and pathology of soft tissues. This thesis briefly outlines the principles of magnetic resonance imaging, including instrumentation. In many cases intravenously administered contrast agents are used, which are used for diagnostic purposes. At present, the most applied are CAs based on Gd(III) complexes. The experimental part of the thesis is focused on preparation of a derivative of DTPA with aminomethylphosphinate pendant group for using as a potential ligand for CAs for the magnetic resonance imaging. KEYWORDS: magnetic resonance imaging, contrast agents, lanthanides, phosphinates
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Methods of insect body and food marking and their utilization in bees (Anthophila)
Macháčková, Lenka ; Straka, Jakub (advisor) ; Bogusch, Petr (referee) ; Hanus, Robert (referee)
Marking methods represent often an essential part of many studies which target on insect biology. These marking techniques sometimes represent the only possible way to obtain new and important informations. In the first part of the thesis I deal with individual insect labeling, which was used for marking of solitary bees and their nests as a tool of obtaining informations about nesting bee dynamics in aggregation. Our study show that nest owner replacements are very common in all four species. However, a large percentage of the nests were abandoned by the female owners before owner change. Only a part of all the nests were trully usurped on the nesting site. The true usurpations thus represent rather minor part of observed nest owner replacement situations. The bees surprisingly often abandon their nests and found the new ones. The frequent contacts of the females on a nesting site occur as a result of common nest owner replacements. High tolerance of bees to each other together with tolerance of usurpations and low level of aggression may thus represent one of the possible ways towards communality and other types of social behaviour. In the second part of the thesis I focus on the possibilities of food marking in bees. Effectivity of sugar and pollen utilization are not yet fully understood in...
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Synthesis of unsymmetric DOTA derivatives and study of their complexes
Obuch, Jakub ; Hermann, Petr (advisor) ; Drahoš, Bohuslav (referee)
Lanthanide(III) complexes are compounds with both diagnostic and therapeutic applications. For diagnostic applications, they are used as contrast agents for imaging techniques such as MRI, PET or SPECT. In therapy, complexes of beta or alpha particle- emitting radionuclides are used. If the complexes contain protonable groups, their behaviour is dependent on pH of the solution. Protonation of these groups should occur close to the physiological pH. If the efficiency (relaxivity) of the MRI contrast agent is dependent on protonation state, this method can be used for determination of pH of tissues in vivo. For radiopharmaceuticals, fast complexation of short-lived metal radionuclides is important and protonation might significantly accelerate the complex formation. For therapeutic applications, possibility of labelling at low temperatures when heat-sensitive biovectors (e.g. antibodies) do not decompose. To assess the effect of protonation of amino group in the vicinity of the metal ion, amino-bis(phosphinate) pendant arm was proposed, where the dissociation constant of the amino group below the physiological pH can be expected. Three ligands containing this group and DO3A fragment were prepared and their complexes were studied to assess aforementioned possible uses in medicine. Their structure and...
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