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Surface structures of implants produced by 3D printing
Koutný, Michael ; Rebenda, David (referee) ; Ranuša, Matúš (advisor)
The additive technology is currently also used in endoprosthetics, in which the damaged or diseased part of the joint is replaced with artificial endoprosthesis implants. The problem lies in the spaces of articulating surfaces, where microstructures created by manufacturing can affect tribological properties. This work is concerned with assessing the effect of microstructure defects on the surface of endoprostheses, with an assessment of lubrication and friction properties at the points of contact using a reciprocal tribometer and an optical profilometer. Additively manufactured Ti6Al4V titanium alloy samples with different microstructures were tested, observing the size and number of albumin and globulin from high-speed camera recordings. The results obtained were further compared with texturing. The results obtained can be used as a basis for subsequent studies.
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Fluorescent nanoparticles based on organic chromophores
Čekal, Josef ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This study aims to create Host-Guest nanoparticle systems exhibiting white light emission (WLE) using organic molecules, achieved through Förster resonance energy transfer (FRET) mechanisms. Substituted stilbene-based compounds were utilized for the preparation of nanoparticle systems, with CA-DPS-V (H2) and CA-DPS-CHO (H1) used as donor/matrix materials, and CA-DPS-DCV (G1) and DPA-DXS-IOO (G2) as acceptor/dopant materials. Three nanoparticle systems were synthesized via nanoprecipitation from common solutions of the compounds in THF: system 1 (H1+G1), which did not achieve WLE, system 2 (H2+G1), and system 3 (H2+G2). Systems 2 and 3 were characterized using fluorescence spectroscopy and FRET parameter calculations. It was found that the Förster distance in system 2 is shorter than in system 3. This variation in Förster distance affects the composition ratios capable of WLE. The closest proximity to the white point (0.33, 0.33) was observed in system 2 at molar ratios of 110:1 (0.32, 0.38) and 164:1 (0.29, 0.32), and in system 3 at ratios of 340:1 (0.34, 0.30) and 476:1 (0.31, 0.28). Thus, the goal of the study was achieved, demonstrating that nanoparticles capable of WLE can be prepared in this manner. However, a drawback of the prepared nanoparticles was their low photostability. Future work could focus on synthesizing more stable nanoparticles from structurally similar compounds. These particles could then be further characterized in terms of structure and other properties for potential applications.
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Laser treatment of the surfaces of small human joints
Křístek, Mikuláš ; Odehnal, Lukáš (referee) ; Ranuša, Matúš (advisor)
Nowadays, in osteoarthritis of small joints, total endoprostheses are used to ensure physiological movement; unfortunately, the durability of these joint implants is very limited. The most frequent wear occurs in the contact area of the implants with the articulating surface. The use of microtextures appears to be beneficial in influencing tribological properties, but this issue is not well described. This bachelor thesis investigates the effect of different microtextures on the coefficient of friction, the movement of proteins in the synovial fluid in the contact area, wear, and the surface topography. Measurements were made using a reciprocal tribometer, optical profilometry and fluorescence observation. The textured samples achieved an increase in the coefficient of friction in the contact region. The results show that surface texturing can significantly affect the coefficient of friction in the contact region, which contributes to the reduction of wear and extension of endoprosthesis life.
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Chromophores based on push-pull substituted stilbenes
Ševčíková, Veronika ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This bachelor thesis deals with the examination of the relationship between the structure and optical properties of organic luminophores based on push-pull substituted stilbene and the determination of their emission in the solid state and in solution - dual state emission (DSE). Four newly synthesized luminophores based on push-pull substituted diphenylaminodibromostilbene and diphenylaminodi(2,6-xylil)stilbene containing different electron acceptor groups were selected for measurements. Due to the limited amount of samples, only solutions of the luminophores in dichloromethane were prepared. Emission spectra, quantum yields and fluorescence lifetime were measured for these luminophores in solid state. For solutions of these luminophores in DCM, all described optical properties were measured along with the absorption spectra. Determined optical properties were related to the structure of the luminophores. For the diphenylamine-dibromostilbene-based luminophores, fluorescence of the NIR radiation was detected, while the fluorescence of these luminophores was found to be weakened due to the presence of Br substituents. The investigated diphenylaminodi(2,6-xylil)stilbene-based luminophores show relatively weak push-pull effect. The fluorescence of these luminophores was found to be intense in solution, but weakened in the solid phase, which was attributed to the weak push-pull effect. According to the measured results, it was concluded that the investigated luminophores based on diphenylaminodi(2,6-xylil)stilbene are suitable candidates for further research and potential applications considering their properties.
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DNA Visualization with Regard to High School Biology Education
Špačková, Lucie ; Ehler, Edvard (advisor) ; Vojíř, Karel (referee)
This bachelor's thesis explores in detail the issue of DNA visualization and its use in the teaching of biology in high schools. It is based on the description of technological methods for DNA visualization, including gel electrophoresis, polymerase chain reaction (PCR), DNA sequencing, fluorescence microscopy and molecular hybridisation. Emphasis is placed on the study of the structure and properties of DNA, including the process of DNA replication, which is essential for the understanding of the function of DNA. It also compares the different types of visualization dyes available for staining DNA, providing a comprehensive overview of their properties and potential. Emphasis is placed on the potential applications of these methods and dyes in the context of high school biology education. Overall, the thesis attempts to provide a comprehensive view of DNA visualization and its use in high school education.
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Use of advanced fluorescence methods in the study of aggregation
Uhrínová, Alžbeta ; Enev, Vojtěch (referee) ; Venerová, Tereza (advisor)
The diploma thesis deals with the use of advanced fluorescence techniques in the study of aggregation of selected aggregation models (casein and sodium dodecyl sulfate). At the beginning of the research, fluorescent probes Atto 488 and Rhodamine 6G (RH6G) were characterized using a spectrofluorometry, UV-VIS spectrometry, time-resolved fluorescence, and fluorescence correlation spectroscopy (FCS). Aggregation models with the addition of fluorescent probes were characterized using the same advanced fluorescence techniques. The interaction between the fluorescent probe Atto 488 and the aggregation models was not confirmed. The excitation maximum of Atto 488 was at 500 nm and the emission maximum at 520 nm. The lifetime of the fluorescent probe Atto 488 was from 4,20 to 4,82 ns and the hydrodynamic radius was determined to 0,6 nm. Rhodamine 6G had an excitation maximum at 525 nm and an emission maximum at 555 nm. The lifetime of the fluorescent probe RH6G was from 3,99 to 5,27 ns. The intensity of RH6G was found to decrease upon addition of a higher concentration of casein, resulting in quenching. The hydrodynamic radius of the RH6G probe was determined to 0,6 nm. With the addition of casein using the maximum entropy method (MEM) evaluation was from 0,5 to 534 nm. Stable SDS micelles had a hydrodynamic radius by MEM evaluation of 2,4 nm.
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Isolation of photosystem II particles and their characterization
Svitačová, Denisa ; Pekař, Miloslav (referee) ; Venerová, Tereza (advisor)
This master's thesis deals with the isolation and characterization of spinach thylakoid membranes and photosystem II particles. Based on the research, two procedures were chosen for the isolation of spinach thylakoid membranes and photosystem II particles with an emphasis on preserving their native properties. Subsequently, the characterizations were carried out, focusing on the spectroscopic properties of the isolated samples. UV-VIS spectrometry was used to determine the ratio of chlorophyll a to chlorophyll b in samples of thylakoid membranes and photosystem II particles. The success of the isolations was confirmed by fluorescence methods. The excitation and emission spectra of the samples were measured by the steady-state fluorescence spectroscopy, and the fluorescence lifetimes of the samples of thylakoid membranes and photosystem II particles were determined by time-resolved fluorescence. The isolated samples were afterwards visualized with a fluorescence microscope with a CCD camera and the FCS technique.
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Influence of plasma treated water on the plant growth and vitality
Vozár, Tomáš ; Zahoranová, Anna (referee) ; Kozáková, Zdenka (advisor)
This diploma thesis deals with the effect of plasma activated water on plant growth and vitality. By interaction of plasma with water, water acquires new unique properties that can be used in agriculture. The theoretical part deals with the basic properties of plasma, possibilities of preparation of plasma activated water in laboratory conditions, its physico-chemical characterization, and possibilities of its use in agriculture. In the next part, plant photosynthesis is discussed in connection with chlorophyll fluorescence, which measures the activity of photosystem II. Activity is an indicator of plant vitality, under environmental changes. At the end of the theoretical part, there are listed further possibilities for the analysis of plant material and food, such as elemental analysis, sensory analysis, and determination of dry matter content. Within the experimental part, plasma activated water (PAW) was prepared using plasma nozzle with introduced gas mixture that was immersed in the treated liquid. Further, plasma activated water was characterized and applied to radish plants. The effect of PAW on the plant growth and vitality was observed. The effect on the growth was observed through determination of fresh weight and dry matter content, the effect on vitality was assessed through chlorophyll fluorescence and the NDVI index. In the end, the effect on the content of stored elements C, H, O, and N in plants was determined and a sensory analysis was performed. The results show positive effects of plasma activated water on the plant growth and its sensory parameters such as appearance, taste, or spiciness. The results further show that PAW does not adversely affect plant vitality. This experiment should be continued by further indoor replication of the experiment to confirm obtained results and then, by moving the experiment to exterior in a form of field experiments.
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Pharmacokinetics of Intramuscularly Administered Thermoresponsive Polyacrylamides
Groborz, Ondřej
6 Pharmacokinetics of Intramuscularly Administered Thermoresponsive Polyacrylamides Author: Ondřej Groborz Supervisor: doc. Mgr. Martin Hrubý, Ph.D., DSc. Institute of Macromolecular Chemistry, Czech Academy of Sciences Advisers: Ing. Pavel Švec RNDr. Lenka Loukotová, PhD. Abstract Polymer solutions with lower critical solution temperature (LCST) undergo a phase separation when heated above their cloud point temperature (TCP). These thermoresponsive polymers have numerous promising medicinal applications, such as in situ depot-forming radiotherapy (brachytherapy), controlled drug-release, immuno-radiotherapy, injectable thermogelling for tissue engineering and cell culture and magnetic resonance imaging (MRI), among others. Yet, despite extensive research on medicinal applications of thermoresponsive polymers, their fate after their administration remains largely unknown. Thus, in our study, we synthesized and thoroughly characterized four different thermoresponsive polyacrylamides, namely poly(N-(2,2-difluoroethyl)acrylamide), poly(N- isopropylacrylamide), poly(N,N-diethylacrylamide) and poly(N-acryloylpyrrolidine) under physiologically relevant conditions. Subsequently, we determined their biodistribution kinetics in mice and proposed a data-based pharmacological model to describe their in vivo behaviour,...
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Fluorescent Methods in Research of Eukaryotic Cells
Chmelíková, Larisa ; Babula, Petr (referee) ; Pešl,, Martin (referee) ; Provazník, Ivo (advisor)
Tato práce zkoumá aplikaci fluorescenčních metod používaných v in vitro studiích v oblasti regenerace srdeční tkáně. Konfokální fluorescenční mikroskopie je vhodnou mikroskopickou technikou pro výzkum v této oblasti, protože umožňuje vizualizaci 3D struktur a distribuce buněk ve 3D modelech. Používané fluorescenční markery by měly být dlouhodobě stabilní, biokompatibilní a netoxické pro živé buňky. V současné době je použití nanočástic jako superparamagnetické nanočástice oxidu železa (SPION) velmi populární; velké množství studií ukazuje, že jsou vhodné pro dlouhodobé experimenty. Tento výzkum využívá superparamagnetické maghemitové nanočástice svázaným rhodaminem na jejich povrchu (SAMN-R) a popisuje jejích excitační a emisní spektrum, velikost a lokalizaci vbuňkách. Stanovení toxicity bylo provedeno měřením reaktivních forem kyslíku (ROS) a nekvantitativním měřením pomocí fluorescenční mikroskopie bylo zjištěno, že hodnota dávky 20 µg·cm-2 je optimální pro aplikaci na živé buňky. Dále byl zkoumán vliv aplikace SAMN-R na buněčnou proliferaci a motilitu, kdy ve studii buněčné proliferace a scratch assay byla použita buněčná linie fibroblastů 3T3. Poté byla studována migrace jednotlivých buněk s použitím mezenchymálních kmenových buněk (MSCs), izolovaných zlidské tukové tkáně. Následná statistická analýza nepotvrdila, že by aplikace SAMN-R měla významný vliv na buněčnou proliferaci, kolektivní migraci nebo na migraci jednotlivých buněk. Lze tedy předpokládat, že SAMN-R jsou vhodným fluorescenčním markerem pro výzkum živých buněk, včetně experimentů voblasti regenerace tkáně. MSC buňky izolované z tukové tkáně mají velký potenciál v regeneraci srdeční tkáně. Jejich interakce s buněčnou linií srdečních svalových buněk HL-1 byly studovány pomocí scratch assay, kdy se tento model jeví jako nadějný a vhodný pro studium buněčných kontaktů a jejich roli přiregeneraci buněk.
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