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Testing of the possible applications of the flow-through dual amperometric detector
Vikartovský, Andrej ; Dejmková, Hana (advisor) ; Baluchová, Simona (referee)
In this work, the possibilities of using an electrochemical dual detector in a flow arrangement were investigated using flow injection analysis. The dual detector was first tested for potassium ferrocyanide for its reversible oxidation at the generation electrode and subsequent reduction at the detection electrode. The possibilities of determination of nitro substances were explored, when hydroxylamine was formed by the reduction of nitro groups on the generation electrode, which was subsequently oxidized on the detection electrode. Thanks to determination in the oxidation potentials, it was possible to avoid the noise caused by oxygen reduction and the detection limit for dinitrophenol 0.47 μmol∙dm−3 was achieved. The possibilities of using a dual detector for detection in reduction potentials by minimizing the influence of oxygen, by reducing it on the generation electrode, were verified. Furthermore, the possibility of using a dual detector for the determination of dopamine in the presence of ascorbic acid based on the reversible oxidation of dopamine and the irreversible oxidation of ascorbic acid was investigated. The limits of dopamine detection using reduction on the detection electrode were 0.31 μmol∙dm−3 in the presence of ascorbic acid with a concentration of 0.1 mmol∙dm−3 . In the...
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Physiological and neurobiological correlates of personality traits
Kubelková, Klára ; Nekovářová, Tereza (advisor) ; Jonáš, Juraj (referee)
This paper seeks to provide an overview of the molecular, genetic, as well as structural and functional correlates of personality traits known to date, focusing primarily on typology according to the extensively used "NEO PI-R" ("Big Five") classification. It also attempts to discuss, at least briefly, the methodology for obtaining both neurobiological and psychological data and its validity. Finally, it aims to highlight the strengths and weaknesses of the neurobiological approach to personality, its potential benefits and pitfalls. It does not aim to establish the exact proportion of biological and sociological factors, but to elucidate the mechanisms involved in this biological conditioning. Although there is now a vast amount of research on the biological substrate of personality, there is considerable inconsistency among these studies, both in terms of methodology and the results provided. Moreover, only a small number of them attempt to explain their findings in terms of possible mechanisms of their effect and thus to integrate them into the broader picture of the brain-personality connection. These and many other limitations of neurobiological research on personality, which receive considerable attention in this thesis, are only a proof of the immense complexity of the human brain and human...
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Digital Detox at Brno University of Technology
Kozlovský, Dominik ; Šťastná, Dagmar (referee) ; Ellederová, Eva (advisor)
Cílem této bakalářské práce je popsat závislost na digitálních technologiích a digitální detox a provézt výzkum zabývající se závislostí na digitálních technologiích a zkušenostmi s digitálním detoxem u studentů a učitelů na Vysokém učení technickém v Brně. Práce zahrnuje rešerši literatury na téma digitální závislosti, digitálního detoxu a výzkum prostřednictvím dotazníku, který byl distribuován studentům a učitelům. Výsledky dotazníkového šetření ukázaly, že více než 70 % respondentů stráví více než dvě hodiny denně na telefonu, přičemž nejpoužívanější aplikace jsou Facebook a Instagram. Současně téměř 70 % respondentů přiznalo, že používají telefon více, než původně zamýšleli, což naznačuje možné symptomy digitální závislosti. Povědomí o digitálním detoxu mělo téměř 90 % respondentů a téměř 50 % respondentů mělo zkušenost s nějakou formou digitálního detoxu. Většina respondentů doporučila digitální detox, což naznačuje jejich povědomí o jeho pozitivních účincích.
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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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Obranné reakce včel vůči přírodním toxinům
KAINZOVÁ, Klára
The aim of this master thesis was to describe the effect of honeybee venom on several physiological characteristics in the honeybees Apis mellifera themselves. They included the expression and level of vitellogenin in selected organs, AKHs production in CNS, level of dopamine in brain, fat body and Malpighian tubules, oxidative stress (the activity of catalase) and the structure of thoracic muscles in workers and drones. Results showed that the bee venom did not change the AKH level in CNS. However, the envenomation decreased the expression of vitellogenin in fat body, as well as the level of vitellogenin proteins both in fat body and haemolymph. Catalase activity was increased in the gut of workers but decreased in the gut of drones. The venoms application slightly increased dopamine levels in the fat body, brain and Malpighian tubules, but only in the fat body the rise was significant. Honeybee venom damaged the structures of myofibrils and mitochondria in the thoracic muscles of workers, however, co-application of the venom with AKH generally abolished this effect; situation in drones remains unknown.
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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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