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Approximation of static moduli of rocks from dynamic moduli determined by sonic well logging using T-matrix model
Chalupa, František ; Vilhelm, Jan (advisor) ; Rudajev, Vladimír (referee) ; Růžek, Bohuslav (referee)
(EN) Thesis deals with an approximation of static moduli in wells from dynamic moduli determined by acoustic well logging using T-matrix model. Proposed approach makes possible to determine moduli values, which are close to values of static moduli, which would be determined by loading tests. This approach is based on an idea, that an intact rock with sufficiently high compressional strength sc and sufficiently high value of static Young's modulus Es, manifests more or less linear elastic behaviour. In such case, the values of static and dynamic moduli are identical. This fact has been experimentally verified for rocks with values of sc and Es in order of higher tens of MPa and GPa respectively. In case of a rock damage presence in such rock, it's behaviour becomes nonlinearly elastic. The amount of nonlinearity is proportional to increasing amount of rock damage. This results in the difference between values of static and dynamic moduli. T-matrix model is used to quantify this difference. This model is based on an anisotropic rock matrix with ellipsoidal inclusions. These inclusions can affect each other. The result of this model calculation is a group of values of elastic constants, which we call effective moduli. These effective moduli include the effect of porosity in the rock as well and they...
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G pretein-couplad receptors in membrane domains
Rudajev, Vladimír ; Svoboda, Petr (advisor) ; Nováková, Olga (referee) ; Teisinger, Jan (referee)
Conclusions our purposewastoseparďeplasmamembranefractioncharacterisedaslipid rafu (or mernbranedomains)andítndtheextentofG protein coupledreceptors(GPCRs) raft association.Threediffererrttechniqueswere applied- detergontextraction,alkaline treaÍnent wift sonicďion,andhomogenisation'We foundtha on|yTriton X.l00 treatmentledto lipid raffs separďon from bulk membranephase.Many markermoleculeshelpedus to characterise low (sucrose|5.25%)andhigh-density(sucrose40%)membranefractionsseparďedon sucrosederrsitygraďents after cells homogenisation'ďkďine or detergentextraction.Low density,dercrgentresisiantmembranefragnents, were characterisedby presenceof mernbranedomainsproteinscaveolin,flotillin, andGPl-boundalkalinephosphatase,CD55, CD58, andCD59, whereashigh-densitysucrosegradientfractionwereenrichedin non-raft proteinsNA/K-ATPase' MHC l' cDl47' calnexinandtrarsferrinerec€ptoÍ'Using alkaline extractionandhomogenisation(detergent-freemethods)ďd notprovide membranedomains separatedfromnon.raflphaseofplasmamembrane. Inadditiontovariousmarkerproteins,gradientdistributionsof GPCRs andtrimericG proteinGso, GqďGl lo', Gil,2a andGp wereanalysedaswell' Innon.deteÍgent prepaÍations,all monitoredproteinsco.localísedin gradientfractionsrepresenting35-4070 sucÍose.on theotherhand,appIicationof TritonX. l 00 enabledus to...
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New approaches in higt-resolution shallow seismic prospection
Valenta, Jan ; Dohnal, Jiří (advisor) ; Rudajev, Vladimír (referee) ; Bárta, Jaroslav (referee)
This work deals with the application of seismic methods in high-resolution near-surface prospection. Two topics are covered in this text. The first one describes processing and application of 3D shallow seismic refraction, while the second one deals with possible methods of identification and filtration of S-waves. The processing of the 3D seismic refraction data is currently carried out mainly by means of the seismic tomography. Because the tomography method usually works with the gradient model of the subsurface, an approach to the layer-based model was sought. The solution was found in a modification of the time-term method. The time- term method was modified to handle also the lateral variations of velocity in highly heterogeneous media. REFRACT3D computer program for data processing using the time-term method was developed. The modified time-term method was successfully tested during the archaeological prospection of the Děvin Castle and during the pro- spection of the shallow subsurface of the Ostaš seismic station. The results from the time-term method were compared with the results obtained by the first arrival travel time tomography. In the case of the Děvin Castle the time-term results surpass the tomography one, while at the locality of Ostaš the tomography results are better. The imaging...
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The role of G protein-coupled receptor signaling systems in neuroprotection
Hofmannová, Adéla ; Novotný, Jiří (advisor) ; Rudajev, Vladimír (referee)
Nervous tissue, especially the brain, is very sensitive to the lack of oxygen and nutrients. Without supply of these components, the tissue endures only a few minutes and then, after the depletion of all ATP, permanent damage or even cell death occurs in neurons and glial cells. During ischemia or hypoxia, an excessive amount of the excitant neurotransmitter glutamate is released, which is neurotoxic. It causes ion imbalance and also apoptotic signaling pathways may be triggered because of the high level of intracellular calcium. Signaling through G protein-coupled receptors (GPCRs) can be involved in the establishment of increased cell resilience to hypoxic injury. Stimulation of some GPCRs, e.g. adenosine, opioid, cannabinoid and melatonin receptors, can afford neuroprotection. Activation of their cognate G proteins may lead to blockade of ion channels or affect the effector proteins, thus helping the stabilization of ion homeostasis and the inhibition of glutamate release. Moreover, some of the receptor agonists have antioxidant character, whereby they prevent the harmful action of free radicals. Neuroprotective mechanisms promote neuronal survival during harmful conditions and are also able to slow down the processes responsible for the development of neurodegenerative diseases. Key words: G...
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Classification, structure and function of α-adrenergic receptors.
Makarova, Anna-Marie ; Hejnová, Lucie (advisor) ; Rudajev, Vladimír (referee)
Adrenergic receptors are ones of the most investigated receptors today. Signal transduction by adrenergic receptors is involved in stress response. Stress activates the sympathicus and the hypothalamic-pituitary-adrenal axis of autonomic nervous system. Understanding effects of this activation on adrenergic signalisation is important for affection of the "fight of flight" reaction. Affecting the activity of sympathetic nerve sis important subject of interest in pharmacology and many drugs are developed using this actions. This thesis deals with a group α-adrenergic receptors and its subtypes. One part is devoted to structure which is subject of many explorations recently especially. Next chapter focuses on signal transduction mediated by α-adrenergic receptors. The last section refers to multitude of physiologic functions induced by these receptors. Powered by TCPDF (www.tcpdf.org)
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The effect of morphine on the distribution of signaling molecules of the opioid system in lipid rafts prepared from rat heart
Ladislav, Marek ; Novotný, Jiří (advisor) ; Rudajev, Vladimír (referee)
Morphine is an opioid agonist, which can exert cardioprotective effects under certain conditions. Lipid rafts are considered important platforms for membrane organization of signaling proteins and, therefore, these structures could play a role in the effects of morphine, which acts through the opioid receptors. The aim of this thesis was to investigate the distribution of the main components of the opioid receptor and Gi/o-mediated signaling pathway in lipid rafts isolated from rat myocardium, which was affected by various doses of morphine. Because we used different isolation techniques with different solubilization agents (Triton X-100, CHAPS, cholate and sodium carbonate) for preparation of lipid rafts, it was of interest to characterize more closely these preparations. Another aim of this study was to investigate how different methods of isolating these structures affect activity of the key target enzyme of the opioid signaling pathway, i.e. adenylyl cyclase. The presence of signaling molecules of the Gi/o/AC pathway of the opioid system in membrane rafts was confirmed and the distribution of selected proteins was dependent on the type of extractant. We also observed the effect of morphine on the localization of proteins in lipid rafts. Different extractants provided different degree of...
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Effect of chronic morphine treatment of rats on myocardial signaling systems regulated by trimeric G-proteins
Škrabalová, Jitka ; Novotný, Jiří (advisor) ; Rudajev, Vladimír (referee)
It has recently been discovered that the effect of morphine can significantly reduce the tissue damage that occurs during myocardial ischemia. The molecular mechanisms by which morphine acts on the heart are still little understood. The aim of this thesis was to monitor the effect of chronic 27-day and 10-day administration of low (1 mg/kg/day) and high (10 mg/kg/ day) doses of morphine on the expression of selected G-protein-coupled receptors (GPCR) and on the expression and activity of adenylyl cyclase (AC). Chronic (27 days) morphine treatment reduced the expression of к-opioids receptors, but 10-day morphine exposure did not influence the expression of these receptors. Assessment of β1- and β2-AR by immunoblot technique did not show any significant change in the expression, but the more accurate determination of β-AR expression using the saturation binding studies revealed that 27-day treatment with high doses of morphine appreciable increased the total number of these receptors. Administration of high doses of morphine led to marked up-regulation of adenylyl cyclase (AC) isoforms V/VI, and the amount of AC decreased proportionally with the time of discontinuation of morphine administration. Low doses of morphine up- regulated AC only during 27-day administration. Chronic morphine exposure did...
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Potential role of opioids in neuroprotection
Gebauer, Martin ; Novotný, Jiří (advisor) ; Rudajev, Vladimír (referee)
The opioids have been used by mankind for more than two millennia, but effect and mechanism of their action on the cells has been unveiling in the last few decades. The mechanism itself is often still unknown, but its effect is observed only. There are several groups of opioid receptors which are able to bind opioids. These groups are characterized by their differe nt affinity to opioids, in some cases by their different effects on cells and by their representation in the various areas in the CNS. Thus, the effects induces by these opioid are very different in many cases. This thesis summarizes the current knowledge about coronary heart disease and the potential of opioids for the prevention and their effect during ischemia, also summarizes the effects of morphine on the CNS. During ischemia δ-opioid receptors play a major role, because they inhibit or block the proapoptotic effects of ischemia on many levels. These receptors are also involved in inducing and maintaining the animal hibernation and protect animal's body against very harmful effects of hibernation, e.g lack of oxygen and nutrients. Morphine is opioid which has been used as anesthetic for longest time. It is well-known opioid and it has the most known derivates. This thesis also summarizes most significant effects of morphine on...
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Endogenous opioids and their physiological significance
Jandová, Gabriela ; Novotný, Jiří (advisor) ; Rudajev, Vladimír (referee)
This study examines the influence of endogenous opioid system on physiological processes. Opioid substances and their receptors are located not only in central but also in peripheral nervous systems, as well as in other tissues. Endogenous opioids are produced in the body and influence a wide-range of physiological functions. They are regulators of pain, emotions, breathing, memory, homeostatic functions, etc. Due to their diversity and variety of effects, they may have many possible medical uses, whether in the field of cardiology, anesthesiology or psychiatry. Since the opioid system influences many physiological processes, the understanding of its properties and functioning is prerequisite for deeper study of those processes. Therefore, the study of opioid system and new discoveries in this field receive a great deal of attention nowadays. Key words: Opioid system, endogenous opioids, receptors, nervous system, physiological functions, pain, emotions, breathing, memory, homeostasis
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