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New approaches in drop coating deposition Raman spectroscopy for sensitive molecular detection
Přikryl, Mikuláš ; Kočišová, Eva (advisor) ; Holoubek, Aleš (referee)
in english: Drop coating deposition Raman spectroscopy is a vibrational spectroscopic method based on the principle of Raman scattering. Deposition of a small volume of solution (μl) of a low concentration (μM) on a special hydrophobic substrate and subsequent drying leads to a formation of a deposit from which we can accumulate a higher quality Raman spectrum than in the case of classical Raman spectroscopy. In this thesis, four contaminants (melamine, picloram, thiram, bentazone) were studied on new nanoparticle-based substrates prepared at our faculty. These hydrophobic substrates were compared to commercial substrates and proven to be suitable for further development. Next, artificially prepared mixtures of pairs of contaminants were studied using the commercial substrate. Every contaminant was detected and differentiated in each of these mixtures using factor analysis at relatively low concentrations. Furthermore, the contaminants were separated in some deposits. However, unknown spectra were detected, probably due to chemical reactions between the contaminants. Possibilities of contaminations or interactions with the substrate were eliminated. Finally, a real sample of infant formula artificially contaminated by melamine was studied. The contaminant was detected at concentrations equal to...
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Drop coating deposition Raman spectroscopy of liposomes with different compositions
Antalík, Andrej ; Kočišová, Eva (advisor) ; Holoubek, Aleš (referee)
Method of drop-coating deposition Raman spectroscopy is a special tech- nique that employs deposition of a small droplet of the sample on a hydro- phobic surface with subsequent solvent removal by evaporation. As a result the concentrated material forms a ring at the edge of the droplet. This techni- que has proven to be efficient for liposome studies at low concentrations. We focused on a study of spectral changes and ring formation in phosphatidylcho- line liposomes due to increasing amount of cholesterol. Higher concentration of cholesterol didn't cause significant changes in membrane structure, such as phase transition, however the ring wasn't formed. Second part of this bache- lor thesis concerns with the search for some alternative surface to previously used SpectRIM TM DCDR plates made by Tienta Sciences, Inc. which are no longer available. The polished calcium fluoride glass (CaF2) seems to be the most suitable for the further use from all tested surfaces. Raman signal at the other surfaces was either weak or spectral bands that don't belong to lipid were observed.
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Comparison of sensitivity of drop coating deposition Raman spectroscopy and surface enhanced Raman spectroscopy for study of biologically important molecules
Sayedová, Shirin ; Kočišová, Eva (advisor) ; Hofbauerová, Kateřina (referee)
The main objective of this work was to compare the sensitivity of two Raman spectroscopy methods, namely the method of drop coating deposition Raman spectroscopy and surface-enhanced Raman spectroscopy for selected biologically significant molecules: dipicolinic acid, acetylsalicylic acid, methylene blue and riboflavin. For the DCDR experiments three hydrophobic surfaces were used: commercial substrate Tienta, polished CaF2 substrateand surface with copper nanoparticles with a gradient of hydrophobicity. Two commercial surfaces were used for the SERS method. Both techniques are suitable for sample measurement at low concentrations and with small initial volumes of solutions. The DCDR method, in contrast to the SERS method, allowed to work with higher excitation radiation power. The SERS technique was markedly more sensitive for a selection of suitable SERS active surface. The spectra obtained by the SERS method were influenced by the way of adsorption of the molecules to the surface. By studying the surface with a gradient of hydrophobicity, we have revealed an effect on the shape of dried drops. The dependence on Raman intensity was not found in the case of methylene blue. For both methods we determined the limit concentrations of solutions of measured molecules that can be detected. We have shown that the...
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Improved determination of DNA duplex stability by using UV spectroscopy
Víšová, Ivana ; Štěpánek, Josef (advisor) ; Kočišová, Eva (referee)
This work deals with determination of thermodynamic parameters concerning the temperature induced decomposition of DNA duplexes. Precise temperature dependences of solution UV absorption spectra have been measured for several concentrations. Proposals and tests of various data analysis procedures, with aim to find out optimal way how to determine the thermodynamic potentials changes, represent the core of the work. It has been demonstrated that the combination of a factor analysis and a fit of thermodynamic equations to temperature dependences of obtained coefficient values, enables these parameters to be obtained from a measurement performed for only one concentration and with better precision than by using the so far recommended method based on a melting temperature determination for several concentrations.
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The amount of inforamtion in the information society and its social consequences
Kočišová, Eva ; Duffková, Jana (advisor) ; Lupač, Petr (referee)
This bachelor thesis presents the problematic of quantitative growth of information volume in the contemporary developed societies (with regard to the historical development). It observes the influence of this growth in some areas of the society (particularly media communication, democracy, science and education) and also in a wider social context. It also examines the change of processing information (and its related behaviour) as a form of adaptation to the large information growth.
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Factors underlying parental decisions about childood vaccination
Kočišová, Eva ; Podaná, Zuzana (advisor) ; Hamplová, Dana (referee)
The presented thesis deals with the issue of mothers' decision-making in relation to their child's vaccination against pneumococcal infections. An on-line survey of mothers was conducted (n = 180) in order to obtain data for the theoretical model based on the theory of planned behavior (TPB). A hierarchical logistic regression was then performed in order to analyze the model with the intention to vaccinate as the dependent variable. The results of the regression analyses were supplemented by results of correlation analyses and non-parametric tests. The theory proved itself as a strong predictive instrument and the results suggest that the attitude is the main predictor of the decision in this non-representative sample of mothers. The subjective norm, as the second construct of the TPB, contributes only in certain case and the perceived behavioral control was not found influential at all. The perception of thread of contraindications of the vaccine proves also influential next to the attitude. The beliefs that mothers hold about the vaccine were analyzed according to mothers intentions to vaccinate (n = 70) or not to (n = 110). These results support the idea that mothers, especially those who do not want to vaccinate their children against pneumococcal infections, decide particularly according to...
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Study of angular and time characteristics of suspensions by using of elastic scattering
Peikertová, Pavlína ; Kočišová, Eva (advisor) ; Holoubek, Aleš (referee)
Elastic light scattering represents relatively simple and noninvasive technique to study angular dependencies of the scattered light intensity that contains important information about scattering objects. In the frame of this thesis the data from adapted computer controlled apparatus Photo-gonio-diffusometre type 42.000 were collected. Experimental set-up was upgraded to use it for small sample volumes. Two model systems were studied: polymer and latex suspensions and real systems: liposomal suspension of various sizes, as well. The size estimation by using of Guinier plot was performed from experimental data. This estimation is in good agreement with the defined sizes in case of model systems. For suspensions of liposomes the results are also in relatively good agreement with expected values. Aggregation process and subsequent sedimentation after addition of porphyrin CuTMPyP4 was observed for silver borohydrid colloid. Acquired time and angular dependencies were processed by factor analysis that is able to make a qualitative and temporal separation of both processes
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Study of oligonucleotide penetration through liposomal membrane
Nováková, Jana ; Kočišová, Eva (advisor) ; Holoubek, Aleš (referee)
Modified oligonucleotides, short pieces of nucleic acids, have become potential candidates for treatment of viral, malignant or genetic diseases. Efficient application of modified oligonucleotides requires their sufficient penetration inside the cell through the lipid membrane. Diploma thesis employs liposomes, synthetic vesicles formed by the lipid bilayer, as a model system for the study of interaction of lipid and complex of homooligonucleotides dT15 with cationic porphyrin CuTMPyP4 using Raman spectroscopy. Raman spectra were measured in solution on the slide and using special technique of drop coating deposition Raman spectroscopy (DCDR) on integrated Raman confocal microspectrophotometer. Processes of liposome formation and sample preparation were optimized. Experimental data were analysed using factor analysis based on singular value decomposition (SVD) algorithm. It was observed that interaction of oligonucleotide with porphyrin induces fluorescent background increase. Raman spectra of complex of oligonucleotide with porphyrin exhibit the domination of porphyrin vibrational bands. Stretching vibrations of lipid assigned to hydrogens of fatty acids are observed in the spectra of complex with liposomes. The observed spectral changes show the interaction of lipid with complex of oligonucleotide and...
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Microcalorimetric determination of RNA triplex thermodynamic stability
Říhová, Martina ; Štěpánek, Josef (advisor) ; Kočišová, Eva (referee)
Nazcv prace: Mikrokalorimelricke slanovcni termodynamicke stability triplexu RNA Autor: Martina Rihova Kaledra (ustav): Fyzikalni ustav UK Vcdouci bakalafske prace: Prof. RNDr. Josef Stcpanck, Csc. e-mail vedouciho: stepjosiyj;karlov.mff.cuni.cz Abstrakt: Prace je zamC'fena na urcovani termodynamickych charaktcristik duplexu a triplexu ribonukleove kyscliny. Rozpad a v/nik komplexu hyl sledovan na diferencnim skcnovacim mikrokalorimelru. Jako vzorky byly pouzity smesne ro/toky syntelicky pfipravenych homopolymerii RNA, polyA a polyU, o ruznych stcchiometrickych pomerech. Z namcfenych dal byly urceny termodynamickc paramclry komplexu, tcdy odpovidajici zmeny entalpie AH a entropic AS a teplola tani komplexu. Vysledky ukazaly, /e pfi techto mcfcnich dochazi k systematickc /mene namerenych charakteristik pfi opakovanych scanech. Tento jcv patrnc souvisi s intcrakci RNA s povrchem mefici kyvcty a jc tedy zavazny z hlediska aplikovatclnosli scanovaci mikrokalorimctric pro pfesna kvantitativni tennodynamicka studia ribonukleove kyscliny. Zmcny teploty tani zpusobenc pridanim hofciku do rozloku uka/aly, zc jeho ucinkem so pfi pfipojeni ifctiho vlakna k duplexu RNA komplex stabilizuje. Klicova slova: triplex RNA, duplex RNA, mikrokalorimetric, termodynamickc charakteristiky, teplota tani. Title: Microcalorimetric...
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Drop coating deposition Raman microspectroscopy (DCDR) of carbohydrates
Novák, David ; Kopecký, Vladimír (advisor) ; Kočišová, Eva (referee)
The work is focused on the usage of drop-coating Raman (DCDR) spectroscopy in the study of carbohydrates. DCDR spectroscopy offers a lowering of the detection limits by the coffee-ring effect and minimization of the water signal while keeping similarity to the spectrum obtained from the solution. The similarity is achieved due to the glassy phase, in which molecules have a random orientation and probably retain the first solvation envelope. However, for small molecules, the situation is complicated by both the low efficiency of the coffee-ring effect and the tendency to crystallize. In this work, we studied glucose, galactose, lactose, maltose, trehalose and cyclodextrin to cover the basic structural diversity of sugars - from monosaccharides, disaccharides to oligosaccharides. It was successfully found the concentration range for DCDR spectroscopy of mono and disaccharides (ca. 1-30 mM), while maintaining the glassy phase of the deposit, and to point out the complications associated with the crystallization of polysaccharides. We compared the obtained DCDR spectra with the spectra of polycrystalline samples, from which they clearly differed. Subsequently, we measured the concentration dependences, up to saturated solutions, whose Raman spectra were analysed by factor analysis to capture the...
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