National Repository of Grey Literature 28 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
The analysis of membrane potential recovery in yeast under CCCP-induced stress
Babuka, David ; Plášek, Jaromír (advisor)
The master's thesis is focused on the study of response of the intracellular pH of the yeast cells on various external environments, primarily in a relation to the protonophore carbonyl cyanide m-chlorophenylhydrazone, CCCP. To measure the intracellular pH of the yeast cells we used a genetically coded fluorescent probe the ratiometric pHluorin. Using the method of synchronously scanned fluorescent spectra we were able to measure the intracellular pH of the cells with high precision. As a part of these experiments we also studied the influence of ionic strength of the cell suspensions buffers on the surface potential as well as the influence of the mineral salt KCl on the depolarization of the yeast membranes and cytosolic acidification induced by the protonophore CCCP. We examined the changes of cytosolic pH as such but we also used the measured pH as an indicator of the processes and the state of environment outside the cell. One of the most notable outcomes of this thesis is a new method of monitoring the value of the surface potential of the yeast cells by measuring the titration curves of cytosolic acidification induced by the protonophore CCCP.
Collagen structures from cell culture to intact tendon
Hadraba, Daniel ; Jelen, Karel (advisor) ; Amler, Evžen (referee) ; Plášek, Jaromír (referee)
CHARLES UNIVERSITY and HASSELT UNIVERSITY / tUL Doctoral dissertation Collagen structures from cell culture to intact tendon ABSTRACT Author: Daniel Hadraba Promoters: Assoc. Prof. Karel Jelen | Charles University Prof. Marcel Ameloot | Hasselt University Co-promoters: Dr. Frantisek Lopot | Charles University Prof. Virginie Bito | Hasselt University Annotation Author: Ing. Mgr. Daniel Hadraba Doctoral thesis title: Collagen structures from cell culture to intact tendon Year: 2010 - 2017 Doctoral program: Doctor of Biomechanics at Charles University Doctor of Biomedical Science at Hasselt University / transnational University Limburg Departments: Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Dept. Biophysics | Hasselt University Promoters: Assoc. Prof. Karel Jelen | Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Prof. Marcel Ameloot | Hasselt University / transnational University Limburg Co-promoters: Dr. Frantisek Lopot | Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Prof. Virginie Bito | Hasselt University / transnational University Limburg Bibliography details: Pages 102 Figures 30 Tables 2 Equations 17 Keywords: tendon, collagen, crimps, orientation, aging,...
The analysis of membrane potential recovery in yeast under CCCP-induced stress
Babuka, David ; Plášek, Jaromír (advisor) ; Sigler, Karel (referee)
The master's thesis is focused on the study of response of the intracellular pH of the yeast cells on various external environments, primarily in a relation to the protonophore carbonyl cyanide m-chlorophenylhydrazone, CCCP. To measure the intracellular pH of the yeast cells we used a genetically coded fluorescent probe the ratiometric pHluorin. Using the method of synchronously scanned fluorescent spectra we were able to measure the intracellular pH of the cells with high precision. As a part of these experiments we also studied the influence of ionic strength of the cell suspensions buffers on the surface potential as well as the influence of the mineral salt KCl on the depolarization of the yeast membranes and cytosolic acidification induced by the protonophore CCCP. We examined the changes of cytosolic pH as such but we also used the measured pH as an indicator of the processes and the state of environment outside the cell. One of the most notable outcomes of this thesis is a new method of monitoring the value of the surface potential of the yeast cells by measuring the titration curves of cytosolic acidification induced by the protonophore CCCP.
Nanofiber scaffolds for incisional hernia regeneration
Plencner, Martin ; Amler, Evžen (advisor) ; Kochová, Petra (referee) ; Plášek, Jaromír (referee)
Incisional hernia is the most common postoperative complication which affects up to 20% of patients after abdominal surgery. Insertion of a synthetic surgical mesh has become the standard for care in abdominal wall hernia repair. However, implementation of a mesh does not reduce the risk of recurrence and the onset of hernia recurrence is only delayed by 2-3 years. Nowadays, more than one hundred surgical meshes are available on the market from which the polypropylene is most widely used for abdominal wall hernia repair. Nonetheless, the ideal mesh does not exist yet - it still needs to be developed. The aim of the present study was to develop a functionalized scaffold for abdominal wall hernia regeneration and in vitro testing of the new microsphere system with potential use as a drug delivery system in tissue engineering. We prepared novel composite scaffolds based on a polypropylene surgical mesh functionalized with polycaprolactone nanofibers and adhered either platelet as a natural source of growth factors or a synthetic growth factor. In extensive in vitro tests, we have proven the biocompatibility of polycaprolactone nanofibers with adhered platelets on a polypropylene mesh. A histological and biomechanical evaluation from in vivo tests revealed better healing capacity of our composite...
Deconvolution fluorescence microscopy of yeast cells
Štec, Tomáš ; Plášek, Jaromír (advisor) ; Heřman, Petr (referee)
Title: Deconvolution fluorescence microscopy of yeast cells Author: Tomáš Štec Department: Institute of Physics of Charles University Supervisor: prof. RNDr. Jarmoír Plášek, CSc., Institute of Physics of Charles Uni- versity Abstract: Fluorescence microscopy presents an fast and cheap alternative to more advanced imaging methods like confocal and electron microscopy, even though it is subject to heavy image distortion. It is possible to recover most of the original distortion-free image using deconvolution in computer image processing. This al- lows reconstruction of 3D structure of studied objects. Deconvolution procedure of NIS Elements AR program undergoes an thorough inspection in this diploma the- sis. It is then applied on restoration of 3D structure of calcofluor stained cell wall of budding yeast Saccharomyces cerevisiae. Changes of the structure of the cell wall during cell ageing are being examined. Cell wall of aged cells shows increased surface roughness and even ruptures at the end of cell life. Keywords: fluorescence, microscopy, deconvolution, NIS Elements AR, calcofluor, yeast, cell wall, ageing
Enhanced emission on metal nanostructures
Alt, Václav ; Heřman, Petr (advisor) ; Plášek, Jaromír (referee)
Today, fluorescence is a broadly used phenomenon. It is known, that in presence of metal nanostructures the fluorescence emission rate can be extensively enhanced. In this thesis we study the preparation of such nanostructures, specifically in the form of a thin film made of many silver islands, followed by measuring the expected enhancement. We try several methods for enhancement evaluation, two of which lead to usable results. Thesis contains description of nanostructures preparation, explanation of used methods and measured emission and excitation spectra of used fluorophores. Powered by TCPDF (www.tcpdf.org)
Response of plasma membrane potential and intracellular pH of yeast to changes in the concentration of extracellular K+
Babuka, David ; Plášek, Jaromír (advisor) ; Heřman, Petr (referee)
The bachelor thesis is focused on studying yeast cells and their response to various external conditions. Main focus was on the study of intracellular pH and membrane potential change under the condition of varying extracellular concentration of K+ ions. In particular we studied to what extent are the yeast cells able to compensate these changes. The ability of yeasts to resist the changes of external pH of the cell medium was studied in an experiment complementary to the measurements of intracellular pH. To measure the intracellular pH a genetically encoded fluorescent probe ratiometric pHluorin was used and to measure the changes of membrane potential a fluorescent probe diS-C3(3) was used. Also we successfully applied a method of synchronously scanned fluorescence to supress the cell autofluorescence.
Changes of intracellular pH in yeast cells under stress conditions
Divín, Radek ; Plášek, Jaromír (advisor) ; Krůšek, Jan (referee)
Title: Changes of intracellular pH in yeast cells under stress conditions Author: Radek Divín Department: Institute of Physics of Charles University Supervisor: prof. RNDr. Jaromír Plášek, CSc. Abstract: Specific values of intracellular pH (pHi) can affect all biochemical processes in a cell and this phenomenon is closely connected with the degree of importance of changes in the intracellular pH under the stress conditions. In the Master Thesis, the yeast cells Saccharomyces cerevisiae were used as a model of organism eukaryotic cells. Monitoring of intracellular pH of the cells was performed by the method of synchronous fluorescence scan technique of genetically encoded fluorescent probes pHluorin which was located in the cytosol of the cells. The cells were exposed to stress conditions due to the chemical changes in the environment. Consequently, their ability to maintain a stable value of the intracellular pH in various acidic environments was studied in more detail. The attention was also focused on the impact on optimizing of glucose cytosolic pH. The work was centered on the changes in intracellular pH under the influence of the presence of KCl in suspension. Furthermore, the decrease of cytosolic pH of monitored cells by protonophore CCCP was investigated. The effect of stress environment on the...
Raman Microspectroscopy and Mapping of Single Cells
Gregorová, Šárka ; Mojzeš, Peter (advisor) ; Plášek, Jaromír (referee)
Raman microspectroscopy enables one to acquire spectra of Raman scattering with a spatial resolution in the order of a few μm3 and thus to study the natural composition of biological objects such as tissues, single cells and cellular organelles in a non-invasive way. In this work, we used Raman microspectroscopy to investigate vacuoles of the opportunistic human yeast pathogen Candida albicans. Large sets of Raman spectra of vacuoles were collected based on different cultivation protocols. The sets of the spectra were evaluated using the multivariate statistical method of singular value decomposition. Based on the spectral analysis, we characterized the chemical composition of the vacuoles. We found out that the vacuoles of cells cultured differently or in different media vary particularly in the concentration of polyphosphate, represented in the spectra by the peak near 1155 cm-1 . Interestingly, the wavenumber position of the polyphosphate peak may also be shifted by several cm-1 . We studied these shifts in vitro with sodium hexametaphosphate as a model of vacuolar polyphosphate. Based on these experiments, we suggest that the peak position is significantly influenced by the concentration of divalent cations.
Imaging of fluorescently labelled mitochondria using Biplane_FPALM microscopy
Dostál, Marek ; Plášek, Jaromír (advisor) ; Valenta, Jan (referee)
Title: Imaging of fluorescently labelled mitochondria using Biplane FPALM microscopy Author: Bc. Marek Dostál Department: Fyzikální ústav UK Supervisor: prof. RNDr. Jaromír Plášek, CSc. Consultants: RNDr. Petr Ježek, DrSc. Mgr. Hana Engstová, Ph.D. Abstract: In this thesis the results are presented of a search for suitable PCFP markers for a visualization inner and outer mitochondrial membranes by unique biplane FPALM microscope. We participated in debugging the measuring software for the purpose of 3D vizualization mitochondrial nets and determine their parameters. For this purpose were developed two methods. The first one can be applied to determine the parametrs of outer membranes and the second one is applicable to determine parametrs of inner membranes. On smaller statistical file we managed to confirm dependence quality of mitochondrial net on the cell culture conditions. Under stress conditions e.g. hypoxia the quality of mitochondrial net is changed. Keywords: mitochondria, Biplane FPALM, GFP, 3D visualization.

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1 Plášek, Jan
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