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Preparation of nanoparticles and their use as contrast agents for in vivo imaging.
Odehnalová, Nikola ; Kratochvílová, Irena (referee) ; Turánek,, Jaroslav (advisor)
This diploma thesis deals with the optimalization of synthesis of gold nanoparticles and their surface modification allowing their use as contrast agents for in vivo imaging by CT. Gold nanoparticles were prepared by the Turkevich method and characterized by TEM, DLS, MADLS and UV -Vis. Their surface was functionalized with polyethylene glycol containing a thiol group forming a bond with the Au atoms in the surface of gold nanoparticles. The terminal end of the polymer was methylated or containing an aminooxy group forming an orthogonal bond with hyaluronic acid using click-chemistry. The eligibility for in vivo application of the prepared nanoparticles was verified with stability and cytotoxicity tests. The nanoparticles modified by methylated polyethyleneglycol were injected intravenously into a mouse and their application potential as contrast agents were verified by CT.
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Sensoric Properties of Organic Materials
Tmejová, Kateřina ; Zmeškal, Oldřich (referee) ; Kratochvílová, Irena (referee) ; Nešpůrek, Stanislav (advisor)
The first part of the work is aimed to the study of changes of electrical properties of substituted phthalocyanines under the influence of humidity. Thin films were prepared by spin coating technique. During the influenece of humidity electrical conductivity increases. Sorption and desorption and the changes in electrical properties under the repated humidity exposure were investigated as well. Impedance spectroscopy was used for the studies. The second part of this work consists of optical studies and changes of optical parametrsunder the influence of different alcohols (methanol, ethanol, 2-propanol) exposures. The investigated samples were prepared by vacuum evaporation a glow-discharge-induced sublimation. The changes of optical reflectances of the films upon exposure to alcoholvapour-containg atmospheres were studied as a function of alcohol concetration and exposure time.
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Optoelectronic Properties of Organic Semiconductors
Navrátil, Jiří ; Boušek, Jaroslav (referee) ; Kratochvílová, Irena (referee) ; Weiter, Martin (advisor)
The main objective of this thesis is the study of the optical and optoelectronic properties of organic semiconducting materials. At the beginning of this thesis is shown the growing interest in these materials and their practical application. The theoretical part presents the current state of knowledge of studied problematic related to optical phenomena and the transport of charge carriers in organic semiconductors, photochormic phenomena of reversible molecular switch and charge transfer in DNA biopolymeric matrix. Experimental section, which consists of selected author’s publications, includes study of the charge transport, photochromic reversible switching and the role of dopant in pi-conjugated organic polymer system. Conductive and semiconductive characteristics of the DNA biopolymer have been aslo studied. Conductive and photoconductive techniques together with measurement of the optical characteristics have been used for organic semiconductors characterization.
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Photogeneration of Charge Carriers in Organic Semiconductors
Heinrichová, Patricie ; Kratochvílová, Irena (referee) ; Cimrová,, Věra (referee) ; Weiter, Martin (advisor)
The interest in the detail knowledge about elementary electronic processes during photogeneration of charge carriers, which allow achieving higher efficiency of organic solar cells, grows with advent of the commercial organic solar cells production. The thesis is focused on study of photogeneration of charge carriers in organic semiconductors, especially in -conjugated polymer materials. First part of the thesis summarized state of the art in studies of photogeneration of charge carriers in polymer solar cells. Subsequent experimental and results part are focused on study of polymeric solar cells prepared from electron donor polymers MDMO-PPV, Tg-PPV, PCDTBT and PCBTDPP and electron acceptor derivates of fullerenes PC60BM and PC70BM. Results of the thesis are divided in tree main parts: 1) study of charge transfer between electron donor and electron acceptor materials by optical methods, 2) study of charge transfer between electron donor and electron acceptor materials by optoelectrical methods and 3) development of organic solar cells on flexible substrates. The last part is focused largely on deposition methods of active materials thin layer.
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Time-lapse monitoring of cell mechanical properties
Přibyl, J. ; Rotrekl, V. ; Pešl, M. ; Jelínková, Š. ; Kratochvílová, Irena
Atomic force microscopy (AFM) is a highly sensitive non-invasive surface method able to provide insight into cells' mechanical parameters. Membrane and sub-membrane development, as well as internal cellular properties, can be monitored. The stiffness of cells is a fundamental phenomenon that reflects changes in cell physiology. More importantly, changes in cell mechanical properties are also often found to be closely associated with various disease conditions. Cell mechanics are mainly dependent on cytoskeletal architecture. The development of cryopreserved cells' mechanical properties (stiffness) after thawing was studied using AFM.\n
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Study of changes on spindle and chromosomes vitrified and in vitro maturated human oocytes
Holubová, Kateřina ; Kratochvílová, Irena (advisor) ; Libusová, Lenka (referee)
The aim of this work is the comparison of cryoprotection methods for human oocytes regarding their survival rate and subsequent success in in vitro fertilization. This work showed the effect of oocyte maturation characterized by the state of the meiotic spindle, chromosomes and polar body on the success of in vitro fertilization of standard (fresh) and vitrified oocytes. The acquired knowledge will lead to a better understanding of the relationships between the state of oocytes and specific in vitro fertilization and cryoprotection procedures. The final, application-interesting goal will be to propose the optimization of methods for working with oocytes so that the probability of their success in the IVF cycle is as high as possible.
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Influence of freezing and thawing process on cryopreserved cells nuclei and surfaces. Functions and physico-chemical properties of cryoprotectants.
Golan, Martin ; Kratochvílová, Irena (advisor) ; Raška, Milan (referee) ; Schneider, Bohdan (referee)
1 Abstract: Cryopreservation of cells is a complex process with many useful applications in basic biological research, medicine and agriculture. In this work we deepened the current understanding of the cryopreservation process both at physical and biological level. Results include characteristics of selected cryoprotectants (primarily DMSO, trehalose, antifreeze protein ApAFP752) in liquid phase, during phase transition and in solid phase, as well as their impact on cryopreserved cells states. Specifically, the level of cell viability, state of cell membrane and condition of cell nucleus (nuclear membrane, chromatin condensation, DNA strand breaks) are monitored over several time points after thawing. It is shown that S-phase cells (NHDF and MCF7 lines) suffer massive collapse of replication forks during cryopreservation which makes them much less suitable for cryopreservation than cells in other phases of the cell cycle. Several methods (most importantly Atomic Force Microscopy, Confocal Fluorescence Microscopy and Flow Cytometry) were used to examine the post-thaw state of cryopreserved cells. The acquired insights into cryodamage of cells can lead to optimization of current cryopreservation protocols and to more thorough evaluation of efficacy of future novel cryoprotectants.
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Influence of freezing and thawing process on cryopreserved cells nuclei and surfaces. Functions and physico-chemical properties of cryoprotectants.
Golan, Martin ; Kratochvílová, Irena (advisor)
1 Abstract: Cryopreservation of cells is a complex process with many useful applications in basic biological research, medicine and agriculture. In this work we deepened the current understanding of the cryopreservation process both at physical and biological level. Results include characteristics of selected cryoprotectants (primarily DMSO, trehalose, antifreeze protein ApAFP752) in liquid phase, during phase transition and in solid phase, as well as their impact on cryopreserved cells states. Specifically, the level of cell viability, state of cell membrane and condition of cell nucleus (nuclear membrane, chromatin condensation, DNA strand breaks) are monitored over several time points after thawing. It is shown that S-phase cells (NHDF and MCF7 lines) suffer massive collapse of replication forks during cryopreservation which makes them much less suitable for cryopreservation than cells in other phases of the cell cycle. Several methods (most importantly Atomic Force Microscopy, Confocal Fluorescence Microscopy and Flow Cytometry) were used to examine the post-thaw state of cryopreserved cells. The acquired insights into cryodamage of cells can lead to optimization of current cryopreservation protocols and to more thorough evaluation of efficacy of future novel cryoprotectants.
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Study of changes on spindle and chromosomes vitrified and in vitro maturated human oocytes
Holubová, Kateřina ; Kratochvílová, Irena (advisor) ; Libusová, Lenka (referee)
The aim of this work is the comparison of cryoprotection methods for human oocytes regarding their survival rate and subsequent success in in vitro fertilization. This work showed the effect of oocyte maturation characterized by the state of the meiotic spindle, chromosomes and polar body on the success of in vitro fertilization of standard (fresh) and vitrified oocytes. The acquired knowledge will lead to a better understanding of the relationships between the state of oocytes and specific in vitro fertilization and cryoprotection procedures. The final, application-interesting goal will be to propose the optimization of methods for working with oocytes so that the probability of their success in the IVF cycle is as high as possible.
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Preparation of nanoparticles and their use as contrast agents for in vivo imaging.
Odehnalová, Nikola ; Kratochvílová, Irena (referee) ; Turánek,, Jaroslav (advisor)
This diploma thesis deals with the optimalization of synthesis of gold nanoparticles and their surface modification allowing their use as contrast agents for in vivo imaging by CT. Gold nanoparticles were prepared by the Turkevich method and characterized by TEM, DLS, MADLS and UV -Vis. Their surface was functionalized with polyethylene glycol containing a thiol group forming a bond with the Au atoms in the surface of gold nanoparticles. The terminal end of the polymer was methylated or containing an aminooxy group forming an orthogonal bond with hyaluronic acid using click-chemistry. The eligibility for in vivo application of the prepared nanoparticles was verified with stability and cytotoxicity tests. The nanoparticles modified by methylated polyethyleneglycol were injected intravenously into a mouse and their application potential as contrast agents were verified by CT.
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