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Rheological properties of modified polymer-composite bone pastes
Hlináková, Kristýna ; Vojtová, Lucy (referee) ; Michlovská, Lenka (advisor)
Předložená diplomová práce je zaměřená na studium viscoelastického chování kostních past na bázi fosforečnanu vápenatého a vodného roztoku termosenzitivního triblokového kopolymeru, zlepšujícího tokové vlastnosti pasty. V teoretické části je zpracována stručná charakteristika cementů na bázi fosforečnanu vápenatého. Rovněž se zabývá charakteristikou reologických vlastností injektabilních kostních past. Součástí je také stručný přehled aditiv ovlivňujících právě reologické a mechanické vlastnosti past. Experimentální část je zaměřena na charakterizaci triblokového kopolymeru pomocí nukleární magnetické rezonanční spektroskopie a reologie. Dále byly připravovány modifikované fosfátové cementy, u kterých byly posléze studovány viskoelastické vlastnosti. Kostní pasta byla modifikována přídavkem adhezivních sloučenin (dopamin a jodičnan sodný) a antibakteriálním činidlem (selenové nanočástice). Analýza viskoelastických vlastností byla provedena reologickou analýzou, během níž byl primárně sledován proces vytvrzování a tixotropní chování jak nemodifikovaných, tak modifikovaných fosfátových past. Proces vytvrzování probíhal při teplotě 23 °C a 37 °C, imitující fyziologické prostředí. Morfologie fosfátové keramiky byla charakterizována pomocí rastrovací elektronové mikroskopie a velikost částic byla zjištěna pomocí laserového analyzátoru částic. Bylo prokázáno, že výše zmíněná aditiva mají pozitivní vliv na kinetiku procesu vytvrzování kostních past. Selenové nanočástice navíc vylepšily tixotropní chování polymer-fosfátových past. Z tohoto důvodu jsou tyto nové injektabilní kompozitní pasty vhodné pro miniinvazivní chirurgii. Díky aditivům, vykazujících adhezivní vlastnosti, mají potenciál uplatnit se při léčbě zlomenin. Stejně tak se nabízí možnost využít pasty při léčbě osteomyelitidy, a to díky možnému uvolňování antibakteriálních nanočástic.
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Modification of thermosensitive copolymer with bioactive substances for medical applications
Debnárová, Simona ; Vojtová, Lucy (referee) ; Michlovská, Lenka (advisor)
Biodegradabilné syntetické polyméry nesú vlastnosti, ktoré ich zvýhodňujú oproti iným materiálom používaným na poli regeneratívnej medicíny a tkanivového inžinierstva. Najdôležitejšie výhody zahŕňajú schopnosť prispôsobovať mechanické a chemické vlastnosti aj kinetiku degradácie. Obzvlášť polyestery sú zaujímavé z pohľadu na ich biodegradáciu. Podliehajú hydrolýze, počas ktorej dochádza k štiepeniu esterových väzieb a degradačné produkty sú metabolizované bez akýchkoľvek škodlivých účinkov. Diplomová práca je zameraná na syntetické biodegradabilné triblokové kopolyméry PLGA-PEG-PLGA s obsahom kyseliny polymliečnej (PLA), kyseliny polyglykolovej (PGA) a polyetylénglykolu (PEG), ktoré patria do skupiny biodegradabilných polyesterov. Obsah hydrofilnej a hydrofóbnej zložky polymérneho reťazca spôsobuje amfifilný charakter kopolyméru. Pripravené triblokové kopolyméry sú schopné tvoriť hydrogél pomocou fyzikálneho sieťovania v dôsledku ich amfifilného charakteru. Tieto materiály zaznamenali významný záujem vo vedeckej oblasti. Teoretická časť diplomovej práce všeobecne popisuje hydrogély, bližšie sa venuje fyzikálnemu sieťovaniu amfifilných blokových kopolymérov a mechanizmom degradácie. Podrobný popis triblokového kopolyméru PLGA-PEG-PLGA je rozdelený na PLGA kopolyméry, PEG a ich fyzikálno-chemické vlastnosti. Zahrnuté sú aj poznatky o chemickej funkcionalizácii anhydridom kyseliny jantárovej, anhydridom kyseliny itakonovej a kyselinou listovou. Dopamín je prezentovaný ako spájací faktor a spomenuté sú taktiež najdôležitejšie bioaktívne látky. Experimentálna časť sa zaoberá konkrétnymi metódami syntézy, ktoré viedli k funkcionalizácii a modifikácii triblokových kopolymérov PLGA-PEG-PLGA. Funkcionalizáciou anhydridom kyseliny itakonovej bol získaný kopolymér s oboma koncami obohatenými o reaktívne dvojité väzby a karboxylové funkčné skupiny. Dvojité väzby umožňujú chemické sieťovanie a koncové karboxylové skupiny ponúkajú možnosť modifikácie kopolyméru biologicky aktívnymi látkami. Modifikácia bioaktívnymi látkami L-lyzínom a butylamínom obohacuje polymérnu sieť a dopamín v roli spojovacieho faktoru poskytuje univerzálnosť v naväzovaní bioaktívnych látok, stabilizuje ich a zabezpečuje zachovanie biologickej aktivity naviazaných bioaktívnych látok predĺžením reťazca. Výsledné produkty boli charakterizované pomocou 1H NMR, FTIR a DRA analýz. Funkcionalizácia anhydridom kyseliny itakonovej bola prevádzaná v tavenine. Podarilo sa dosiahnuť vyššieho množstva naviazanej kyseliny itakovovej s hodnotou 79,4 mol % a následné modifikácie boli prevádzané vo vodnom roztoku, organickom roztoku a taktiež v tavenine. Bolo zistené, že najefektívnejšia metóda modifikácie bola syntéza v organickom roztoku s rozpúšťadlom N,N-dimetylformamidom a aktivačným systémom dicyklohexylkarbodiimid/4-(dimetylamino)pyridínom. Najvyššie množstvo naviazaného dopamínu bolo 18,6 mol %, najvyššie množstvo naviazaného butylamínu bolo 7,8 mol % a L-lyzín sa naviazať nepodarilo.
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Molecularly imprinted polymers as a tool for the isolation of key biologically active molecules
Vodová, Milada ; Jaroslava, Bezděková (referee) ; Nejdl, Lukáš (advisor)
This bachelor thesis is focused on preparation and optimization of molecularly imprinted polymers that are selective for the selected nucleobase(uracil). Molecularly imprinted polymers, which wereused for selective uracil isolation, have been prepared non-covalent imprinting technique. As a function monomer was used in this case dopamine. The detection ofisolated uracil was made by capillary electrophoresis with absorption detection (–260 nm). Conditions for preparation of molecularly imprinted polymers,their binding properties, adsorption kinetics, and selectivity wereinvestigatedin detail. Mentioned polymer materials were as well used for uracil selective isolation and detection from complexsamples. Tomato products were used as complex samples. Uracil in those samples was usedasanindicator ofbacterial contamination.
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Mozkový systém odměny u hmyzu
DVOŘÁČEK, Jiří
Animal behavior is not random; rather, it is primarily determined by the biological significance of environmental stimuli: stimuli essential for a survival are marked by the brain reward system, with a positive hedonic value and their achievement is associated with the pleasure (reward). The concept of the reward system emerged from research of the mammalian brain; early theories held that it was a system present only in the brains of higher animals (the mesolimbic dopaminergic system), and that reward was a manifestation of more complex neural networks and higher brain functions. The brain reward has evolved from a solitary phenomenon to a complex function that is divided into the components of ´liking´, ´wanting´, and ´learning´, and from the predominate role of dopamine to a more sophisticated idea that assigns important functions to other neurochemical systems. While dopamine still plays a significant part in the ´wanting´ function, the opioid system likely plays a larger role in the ´liking´ function. The distinction of stimuli into pleasant/unpleasant (attractive/aversive) has been described in insects, and it is widely believed that this principle applies throughout the animal kingdom. Mushroom bodies have been identified as the critical regions of reward functions in the brains of insects. The exact descriptions of the implicated neurotransmitters and modulators, as well as specific cellular and network structures, were also provided. Although the complexity of the brain networks in mammalian and insect reward systems differs, the general principles are the similar in both. The fly Drosophila melanogaster is a frequent laboratory model for investigating the principles of neural network functioning. When studying the brain reward system, it is not only appealing because it is a relatively simple organism with a transparent brain and a described genome, but it may also have the benefit for us that when thinking about its brain, we do not apply relatively old, complex concepts with unlimited meanings, which are a problem in interpreting the human brain study. In the case of the fruit fly, we can highlight that 1) the brain regions involved in associative learning and brain reward functions are surprisingly complex, despite the fact that it is a relatively simple and short-lived organism, 2) its brain almost certainly has a system that creates a motivational drive (´wanting´), and 3) there are indications of the potential existence of a hedonic component of pleasure or its evolutionary predecessor, based not on endogenous opioids. It is inspiring in many ways to compare the brain structures of two evolutionary distinct animal groupsinsects and mammals/humans. This comparison has several implications for a broad paradigm of animal reward, including: Reward principles are universal, and all species are likely fundamentally motivated by the need for rewards. The brain reward mechanisms appear to be hierarchically structured; rather than being centrally organized, they are distributed among other brain networks and mechanisms. The components of these mechanisms can operate independently of one another and concurrently. While the function of neuropeptides in the reward system is flexible, the function of monoamines in the reward system is likely to be conservative in evolutionary terms (the function of endogenous opioids in mammals may be at least partially regulated by another neuropeptide in insects). The neurotransmitter identity of dopaminergic neurons in the reward system is likely to be very context-dependent. Two other interesting concepts can be found in the bee: the sublimation of reward functions in individuals in favor of collective pleasure, and the implied integrated function connecting reward functions and social behavior into one continuum. The comparative study gives new scope for understanding disorders of the reward system, especially addiction, and may also have significant philosophical consequences.
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Designer drugs derived from phenethylamine in relation to the dopaminergic system
Leová, Mara ; Hejnová, Lucie (advisor) ; Lapka, Marek (referee)
The focus of this thesis is on designer drugs structurally derived from phenylethylamine, a trace amine that is a component of dopamine's structure and plays a crucial role in its functioning within the human organism. The dopaminergic system, in general, is vital for regulating mood, motivation, and, last but not least, the mechanisms of addiction. The ratio by which different substances affect the concentration of dopamine and serotonine in the synaptic cleft serves as a significant marker for determining the likelihood of developing addiction to a particular substance. The main body of this thesis comprises groups of phenylethylamine derivatives, their structural descriptions, metabolism, and their potential for abuse. Key words: dopamine, dopaminergic system, phenethylamine, designer drugs, novel psychoactive substances
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Electrochemical behaviour of {110}-oriented single crystal boron-doped diamond electrode for electroanalysis
Poláková, Jana ; Schwarzová, Karolina (advisor) ; Fischer, Jan (referee)
This bachelor thesis deals with the study of the electrochemical behavior of the neurotransmitter dopamine on mechanically polished single crystal boron-doped diamond electrodes with crystal orientation {110} and the boron-to-carbon (B/C) ratio in the gas phase during the chemical vapor deposition process at 250, 500, 1000 and 2000 ppm. Measurements were carried out on mechanically polished, O-terminated and H-terminated electrodes. The redox inner-sphere markers [Fe(CN)6]3−/4− and dopamine/dopamine-o-quinone and the outer- sphere marker [Ru(NH3)6]3+/2+ were used for electrochemical characterization of the polished electrode surface by cyclic voltammetry. As the B/C ratio increases for inner-sphere redox systems, ΔEp values decrease due to the acceleration of heterogeneous electron transfer kinetics. The high values of potential differences indicated that DA behaves quasi-reversibly at BDD electrodes. The ΔEp values for [Ru(NH3)6]3+/2+ showed no trend, confirming the independence of this marker at the doping level. Repeatability was further investigated when several measurements are performed in succession, with the DA solution being stirred before each measurement. It was found that when the solution is stirred, the current response does fluctuate (sr = 9.20), but the potential shows very low...
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Testing of the electrochemical properties of flow-through diamond detector
Pecák, Jakub ; Dejmková, Hana (advisor) ; Vyskočil, Vlastimil (referee)
In the presented bachelor thesis, the functionality of a flow-through multitubular boron- doped diamond electrode (mtBDDE) was verified on two selected neurotransmitters, DA and NE, using the HPLC technique with isocratic elution. An aqueous solution of Britton-Robinson (B-R) buffer was chosen as the mobile phase and a Kinetex EVO C18 reverse column (150 x 4.6 mm) as the stationary phase. The flow rate of the mobile phase was set at 1 ml/min. For electrochemical detection, mtBDDE was used and UV detection at 280 nm was applied as an assistant to the main detector. The electrochemical response of the DA and NE solution (cΘ = 1.10-4 mol/dm3 ) was investigated in the form of hydrodynamic voltammograms over a potential range from 0.1 V to 1.3 V in different pH ranges of the mobile phase (2.5; 4.0; 6.0; 8.0 and 10.0). It was found that the potential wave shifts to lower potentials with increasing pH of the mobile phase, while the response of individual analytes does not change significantly with pH. Under optimal conditions, i.e., mobile phase B-R buffer at pH = 6 and a potential loaded on the mtBDDE of 0.6 V, the repeatability and reproducibility of the measurement results were verified. The electrode gave repeatable results (RSD < 4 %) comparable to the UV detector used (RSD ≤ 4 %) over the series of...
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The influence of Mozart's effect on basketball shooting accuracy in professional basketball players.
Kranjčevič, Stefan ; Pánek, David (advisor) ; Pavlů, Dagmar (referee)
Title: Mozart effect on shooting accuracy of professional basketball players Aims: The aim of this thesis is to demonstrate whether the Mozart effect impacts the success rate of free throws in young premier league basketball players compared to shooting without music. Methods: As this is a pilot study, the data acquisition on this topic first started by examining the previously written text on the Mozart. The project is an experimental pilot study involving 21 probands who were randomized into three groups. The experiment is divided into 2 parts. In the first part participants are asked to shoot one hundred free throws in five blocks of twenty. In the second part, the participants are exposed to different types of acoustic stimulus during which they throw another hundred free throws. All measurements were taken after conditioning or shooting practice for the most authentic replication of the game situation. The process of the practical part was carried out in accordance with the CRISP-DM methodology, which is one of the most widely used methodologies for knowledge capture from databases (KCD). Results: The results show a borderline low correlation between shooting with and without music, according to Pearson's correlation coefficient, with a value of 0.33. The aim of using this statistical function...
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Graphene dopamine biosensor and gate effect
Krajíčková, Kateřina ; Šimšíková, Michaela (referee) ; Bartošík, Miroslav (advisor)
This bachelor’s thesis focuses on investigating the interaction between biochemical substances (dopamine solutions) and graphene, using field effect transistor (FET) based sensors. Graphene possesses unique properties, including biocompatibility, high charge carrier mobility, and surface sensitivity, making it an ideal material for biosensing devices. In these sensors, graphene is employed as the conductive sensing channel within fieldeffect transistors. By utilizing sensors with an FET arrangement, the doping of graphene induced by adsorbed atoms or molecules can be experimentally determined through the observation of the shift in the position of the Dirac point. The measurements can be performed using either the bottom-gated or electrolytic top-gated configuration of the FET sensor, and the thesis explores the differences between the two setups. Furthermore, it investigates the impact of the distance between the graphene and top-gate electrode on the sensor’s response. The results of these measurements are represented by transfer curves, which exhibit characteristic peaks indicating the charge neutrality point, known as the Dirac point, of graphene.
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Optimization of anodic and cathodic pre-treatments of boron doped diamond electrode surfaces for electroanalysis
Baudisová, Kateřina ; Fischer, Jan (advisor) ; Dejmková, Hana (referee)
This bachelor thesis deals with the optimization of anodic and cathodic pretreatment of BDD electrodes and subsequent comprehensive characterization and comparison of electrochemical parameters of unmodified, O-terminated and H-terminated BDD electrodes. The study was carried out using cyclic voltammetry of two model inner sphere redox systems [Fe(CN)6]4−/3− and dopamine/dopamine-o-quinone. Boron concentrations in the BDD films ranged from 500 ppm to 8000 ppm. O-termination of the electrode surface was most effectively achieved when an activation potential of Eakt = +3.0 V was inserted for 10 min into 0.5 mol l−1 H2SO4. For the dopamine/dopamine-o-quinone system, the O-terminated BDD electrodes caused deceleration of electron transfer compared to the unmodified BDD electrodes, which was accompanied by an increase in the potential difference with the highest ΔEp at 500 ppm BBD electrode (ΔEp = 711 mV). To achieve the H-terminal surface, single and cumulative reduction was tested by inserting Eakt = −3.0 V. A sufficient single reduction time for the [Fe(CN)6]4−/3− system was determined to be 60 s, whereas in the case of dopamine, the electrochemical parameters did not stabilize at the selected reduction times, but the cathodic and anodic peak signal at the H-terminated 1000 ppm BDD electrode was up...
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