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Complexes of Cationic Porphyrins with Nucleic Acids Studied by Surface Enhanced Resonance Raman Spectroscopy
Lásková, Barbora ; Mojzeš, Peter (advisor) ; Michl, Martin (referee)
Complexes of cationic porphyrins with nucleic acids are interesting from the point of view of delivery of therapeutic oligonucleotides into cells as well as for photodynamic therapy of cancer. Diploma thesis deals with study of the complexes of cationic metalloporphyrin CuTMPyP4 with poly(dG-dC)2, where intercalation of porphyrin within polynucleotide's base pairs is supposed and with poly(dA-dT)2, poly(dA)·poly(dT), in which external groove-binding of CuTMPyP4 on the helix is assumed. The measurements were made by SERRS, RRS and absorption spectroscopies. From the time evolution of the SERRS spectra for each complex it was found, that intensity of SERRS spectra and rate of SERRS kinetics for complexes fall short of intuitive supposition about low SERRS signal and its slow increasing in the case of intercalation of porphyrin, because for complex of CuTMPyP4 with poly(dG-dC)2, the SERRS kinetic are very fast and final SERRS signal is more intense than for poly(dA-dT)2, poly(dA)·poly(dT). Comparing the SERRS and RRS spectra of the complexes it was found that SERRS spectra correspond to the porphyrin molecules released from the complexes rather that to the entire complexes. Study of various colloidal systems used for SERRS measurements revealed that SERRS signal evolves with time of exposition, namely for...
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Electrochemical, photoelectrochemical and spectroelectrochemical characterization of nanomaterials
Pitňa Lásková, Barbora ; Kavan, Ladislav (advisor) ; Šubrt, Jan (referee) ; Krýsa, Josef (referee)
Titanium dioxide (TiO2) and spinel Li4Ti5O12 belong to widely studied semiconducting metal oxides. Nanocrystalline TiO2 and Li4Ti5O12 are attractive materials for applications in Li-ion batteries and the former also for photoelectrochemical solar cells. Moreover, spinel Li4Ti5O12 could be a promising material for Na-ion batteries too, because of possible accommodation of larger Na+ ions (compared to Li+ ). The nanocrystalline TiO2 anatase with a predominant {001} facet was studied electrochemically by cyclic voltammetry of Li+ insertion and by chronoamperometry and compared with anatase materials with dominating {101} facet. Both voltammetric and chronoamperometric diffusion coefficients and activation energies proved higher activity of anatase {001} nanosheets toward Li+ insertion than that of the usual anatase nanoparticles exposing the {101} facet. Subsequently, the flatband potential and electron kinetics of TiO2 anatase nanocrystals with mostly exposed facet {101} or {001} were compared. The anatase {001} nanoplatelets exhibited more negative flatband potential, higher chemical capacitance and longer electron lifetime than anatase {101} nanoparticles. The Li+ insertion into TiO2 anatase nanoparticles was studied by Raman spectroscopy and by in situ Raman spectroelectrochemistry. Four...
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E-books and copyright
Lašková, Barbora ; Císařová, Zuzana (advisor) ; Wünschová Pujmanová, Alexandra (referee)
LAŠKOVÁ, Barbora E-BOOKS AND COPYRIGHT This rigorous thesis consists of eight chapters, while the aims of the first part are to make readers familiar with the concept of e-books and to describe and to explain the copyright aspect of e-books, to offer to publishers, distributors, libraries and users possibilities of how to use copyrighted e-books legally, namely through conclusion of a license agreement, free share or under a license granted by operation of law. The second part of this thesis deals with methods of e-book protection and description of liability for infringement of copyrights. Conclusion of this thesis is then focused on copyright aspects of e-books de lege ferenda. This thesis is also supposed to give answers to some topical questions related to the e-book phenomenon, which can only be inferred by construing and using case law (European, German and Czech), and at the same time, to address legal problems of e-books, the solution of which should be incorporated in legal norms and put into practice in the future.
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Complexes of Cationic Porphyrins with Nucleic Acids Studied by Surface Enhanced Resonance Raman Spectroscopy
Lásková, Barbora ; Mojzeš, Peter (advisor) ; Michl, Martin (referee)
Complexes of cationic porphyrins with nucleic acids are interesting from the point of view of delivery of therapeutic oligonucleotides into cells as well as for photodynamic therapy of cancer. Diploma thesis deals with study of the complexes of cationic metalloporphyrin CuTMPyP4 with poly(dG-dC)2, where intercalation of porphyrin within polynucleotide's base pairs is supposed and with poly(dA-dT)2, poly(dA)·poly(dT), in which external groove-binding of CuTMPyP4 on the helix is assumed. The measurements were made by SERRS, RRS and absorption spectroscopies. From the time evolution of the SERRS spectra for each complex it was found, that intensity of SERRS spectra and rate of SERRS kinetics for complexes fall short of intuitive supposition about low SERRS signal and its slow increasing in the case of intercalation of porphyrin, because for complex of CuTMPyP4 with poly(dG-dC)2, the SERRS kinetic are very fast and final SERRS signal is more intense than for poly(dA-dT)2, poly(dA)·poly(dT). Comparing the SERRS and RRS spectra of the complexes it was found that SERRS spectra correspond to the porphyrin molecules released from the complexes rather that to the entire complexes. Study of various colloidal systems used for SERRS measurements revealed that SERRS signal evolves with time of exposition, namely for...
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Value added tax burden on low-income households
Lásková, Barbora ; Zídková, Hana (advisor) ; Pavel, Jan (referee)
The aim of this Bachelor thesis is to analyse the tax burden low-income households endured in comparison to the richer ones in relation to the development of value added tax rates from 2007 to 2013, both in absolute and relative terms. The first chapter focuses on the description of developments in VAT, and on setting principles for the subsequent analysis. The second chapter summarizes data from the Household consumption expenditure - National accounts and presents methodology used for the data analysis for the period 2007-2013. The third chapter analyzes the tax burden of low-income and richer households in absolute as well as relative terms and describes the structure of their expenditures and the ratio of paid VAT to their net cash income.
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Electrochemical and spectroelectrochemical study of nanocrystalline TiO2 anatase with exposed (001) faces
Lásková, Barbora ; Zukalová, Markéta ; Bouša, Milan ; Kavan, Ladislav ; Liska, P. ; Grätzel, M.
The electrochemical and spectroelectrochemical behavior ot TiO2 anatase with a predominant (001) face was studied and compared to a reference anatase material with dominating (101) face. The electrochemical measurements indicate that Li-ion insertion/extraction is facilitated for TiO2 anatase with (001) faces as compared to (101) one. The performance of both different crystal morphologies as a photoanode material in DSC (dye sensitized solar cell) was tested too. The (001) face adsorbed smaller amount of the used dye sensitizer (C101) but provides larger open circuit voltage (Uoc) of the solar cell. The different band energetics of both particular morphologies was suggested to be the reason for the voltage enhancement of the device employing (001) anatase. To prove our hypothesis and determine their flatband potential, a spectroelectrochemical study of transparent films of nanocrystalline (001) and (101) anatase on coaducting glass was carried out. UV/Vis spectra were measured at potentials between 0 and -1.4V vs SCE and confirmed the negative shift of flatband potential for (001) anatase as compared to (101) one.
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Modification of TiO2 electronic properties by means of chemical treatment (doping)
Zukalová, Markéta ; Lásková, Barbora ; Procházka, Jan ; Bastl, Zdeněk ; Havlíček, D. ; Kavan, Ladislav
The product of the reaction of nanofibrous anatase with ammonia in gas phase is nanofibrous cubic titanium oxynitride, c-TiO2N3. In contrary to the preparation of cubic titaniurn oxynitride from microcrystalline TiO2, requiring temperatures above 800°C, the conversion of nanofibrous TiO2 to TiO2N3 is completed at about 500°C due to its enhanced chemical reactivity. This conversion is fully reversible; the product of the back reaction is again nanofibrous Ti02. By the thermal treatment of nanofibrous anatase in H2 flow at 800°C for 2 hours the mixture of black disordered anatase, rutile and titanium suboxides was prepared. Evidently, particular phases can be synthesized simply by tuning the temperature of the treatment, which is a subject of the further research.
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