|
Synthesis of ceramide and dihydroceramide analogues and evaluation of their effects on the skin barrier properties
Jandovská, Kateřina ; Vávrová, Kateřina (advisor) ; Roh, Jaroslav (referee)
Jandovská, Kateřina: Synthesis of ceramide and dihydroceramide analogues and evaluation of their effects on the skin barrier properties. Ceramides belong to sphingolipids, their molecule is formed by a sphingoid base and long fatty acid. They are known not just as important second messengers playing a significant role in cell differentiation, proliferation and apoptosis, but also as essential part of functional skin barrier. Although these molecules are studied intensively, the exact effect of their structure on barrier function of the skin is poorly understood. The aim of my work was to study the effect of acyl chain length and stereochemistry on C3 of dihydroceramides (ceramides with single bond on C4) on the permeability of model membranes simulating the skin barrier. I have synthetized 3 ceramides with short acyl chain of 4 carbons (derived from dihydrosphingosine (dS), L-threo-dihydrosphingosine (L-dS) and L-threo-sphingosine (L-S)), and prepared model membranes of stratum corneum (SC) containing dihydroceramides with C2, C4, C6, C8 and C24 acyl chain length and stereoisomeres of C4-ceramides and C4-dihydroceramides as well. I have evaluated their electrical impedance and permeability for two model drugs. The effects of the prepared ceramides on the model membrane permeability were evaluated...
|
|
Trace elements in carbonates of the Czech Creataceous Basin
Štěpánková, Anna ; Procházka, Václav (advisor) ; Štaffen, Zdeněk (referee)
The presented work is focused on research of distribution of trace elements in carbonate sediments and fossils in the Bohemian Cretaceous Basin. To obtain maximum information about the composition of the primary carbonate and its crystallization environment, the trace elements were analyzed mainly in fractions soluble in diluted acid. Another objective is the comparison of trace-element abundance in the soluble fraction and in the residue (or in the total mass of the samples). The results show that there are no systematic differences in the chemical composition of the original carbonate between various regions and stratigraphic positions (Cenomanian - upper Turonian). Elements like Sr, Mg and Mn in carbonate were affected by diagenesis, but contents and mutual ratios of the rare earth elements in all carbonates are similar and are characterized by negative cerium anomaly. The Ce-anomaly could be attenuated by elevated content of clastic matter, and in the soluble portions ocassionally via contamination by secondary phosphate. On the other hand, soluble fractions of limonite-rich and calcite-poor sandstones have positive cerium anomaly, which is the effect of Ce-sorbtion on limonite.
|
|
Development and Use of Electrochemical Detector for Analysis of Czech Coal Combustion Products
Sokol, Martin ; Nesměrák, Karel (advisor) ; Vyskočil, Vlastimil (referee)
This work examines an electrochemical determination of mixed nitric and sulphuric acid solution that is formed during calorimetric determination of gross calorific value of coal carried out under the ISO 1928:1995 standard. Knowing the amount of these acids is necessary for calculating net calorific value. The named standard only allows use of volumetric methods which are time-consuming. Conductivity and ion-selective measurements were used here which significantly shortened analysis time. Overall conductivity measurement was taken with a 4-electrode meter while nitric acid was measured with a nitrate ISE by known addition method. Sulphuric acid was then calculated according to actual temperature. This research has defined the calibration relations and temperature effect. Several simulated and real-world samples were analysed and the method was evaluated for a possible use in a future automated analyser.
|
|
Evaluation of positives and negatives of accession of the Czech Republic to the European Monetary Union
Kabešová, Karin ; Korda, Jan (advisor)
This paper is evaluating earnings and costs of the accession of the Czech Republic to the European monetary union. It defines the Theory of Optimal Currency Areas, both classic and modern approach, and brings up arguments for and against the accession to the monetary union. Further it deals with costs and earnings of the membership in the monetary union both in theory and as an approximate enumeration. It evaluates fulfilling of Maastricht criteria by Czech Republic and simulates its stay in the ERM II system. As the conclusion it states the later date of accession as the most favorable solution for the Czech Republic.
|
|
Serological diagnosis of toxoplasmosis
KAASOVÁ, Eliška
Toxoplasmosis caused by the protozoan Toxoplasma Gondii is one of the most widespread parasitic infection in the world, occurring in organism of both warm-blooded animals and humans. The majority of healthy individuals have no symptoms, in some cases there are slight clinical signs. However, serious heath complications or even death may be caused either by infection or reactivation of the latent form of infection among people with immunodeficiencies. Toxoplasmosis can inflict a severe fetal damage when a female is infected for the very first time in the first trimester of pregnancy. This can be prevented by the risk group screening and an early detection of the protozoan. Laboratory diagnostics use two basic methods in order to prove toxoplasmosis, a direct one and an indirect one. The direct methods such as a microscopic evidence of the protozoan or the isolation of Toxoplasma Gondii on laboratory animals are not usually used in practice. In recent years methods of molecular biology focused on the proof of the protozoan?s nuclear acid in the biological material come to the fore. The methods of indirect evidence are based on the detection of specific traces left by the infectious agent in human organism. Among them, serological methods are the most commonly used ones in the routine operation in the majority of laboratories in the Czech Republic. A basic principle is reaction between antigen and antibody. It is possible to determine whether the infection is in acute or chronic phase and what type of infection it is. This test was utilized for serological evidence of toxoplasmosis for the first time. Then other tests were made. That includes intradermal and imunofluorecent tests, complement fixation test, indirect hemaglutination, microprecipitation or imunoenzymatic methods. The mere evidence of the presence of antibodies is not usually sufficient for diagnosis. Determination of the phase of infection is essential, therefore it is needed to prove if the value of each class of immunoglobulins (or titers of all antibodies) increases, decreases or if they have a stable value. In some cases the avidity IgG may be crucial. The aim of this bachelor thesis is to detect antibodies against Toxoplasma Gondii and to evaluate their prevalence by using serological methods. And finally, these methods will be compared. The patient samples originate from the department of parasitology and serology of Fakultní nemocnice Plzeň, therefore there is an evaluation of the incidence of infection in Pilsen region. The complement fixation test is the most commonly used in routine operation for determination of the total level of antibodies or this test is supplemented by determination of levels of individual immunoglobulin classes by using the Enzyme linked immunosorbent assay. If there is the evidence of infection of toxoplasma by using KFR and the antibody titer is 1:8, it is necessary to supplement the determination by ELSA method to ascertain the level of immunoglobulin classes. This diagnosis has gradually developed from demanding and complex procedures towards fast and fully automated diagnosis. In total, 68 samples of patients with suspicion of toxoplasmosis were determined. The monitored group includes men, women and children. After consideration of the factors which may influence the reaction and on the basis of KFR, the infection of 26 persons was eliminated (negative results). The remaining 43 patients had a positive reaction for the presence of antibodies. After comparing the positive results and low titers with the clinical state of the patient or with the values measured in the past, the determination by the method of ELISA was indicated among 41 persons. The final result for August 2012 was the detection of acute toxoplasma infection of 4 people.
|
|
Vývoj zkušebních metod pro testování pevnosti a trvanlivosti nábytku během jeho namáhání při dopravě
Hlavatý, Josef
The work focuses on the methods of testing the adhesive bonded joint, where the furniture in logistics operations stressed by the extreme temperatures in both the positive and negative direction. This factor has a major influence on the choice of appropriate adhesives that their resistance will correspond to the required properties. Research is extended to new methods of stress glued joints in conditions simulating stress in everyday practice transport logistics. Research is the starting point of the test materials, adhesives and furniture coverings which current manufacturing processes used. The methods are evaluated and designed mainly of mechanical properties and practical utility in the manufacture of furniture. At the same verification testing methodology is the basis for the implementation of these methods in the field of material testing in sections furniture testing and testing of adhesives and plastics. Their initial and explanatory description of the experimental part of the work.
|
|
Software Estimation
Surňák, Peter ; Buchalcevová, Alena (advisor) ; Stanovská, Iva (referee)
This thesis deals with software estimation, describes individual methods which may be used for constructing estimates in terms of effort, time and costs. It also deals with quality of estimate, the way it is used, the process of selection of the right method and other consequences. The main goal of thesis is creating a compact overview of currently known and used methods and approaches to constructing estimates. As a secondary target comes an example of practical use of estimate on a simulated project, where the way of choosing estimating method is presented, based on project attributes such as size, current stage of project or project type. For achieving these intentions, it is important to first set up basic framework of basic terms such as estimate, estimating, project and software project. Apart from just defining these terms, there are some necessary interrelations which must be explained before anything else. Another step is creating categorization of particular methods, their description, restrictions and suitable uses. The quality of an estimate, including factors which may bias, degrade or improve it, is another step towards final goal. Consequences, which may arise when wrong estimate has been provided, are one more piece of mosaic to this work. Lastly, case study demonstrate how to choose from estimating methods and use them on particular project. The expected benefits of the thesis are mainly in summarizing of existing approaches to the art of estimating broken down to categories, as well as list of principles and factors which affects an estimate and the ways estimates influence the project (in either positive or negative direction).
|
|
Control Techniques of Grid Connected PWM Rectifiers under Unbalanced Input Voltage Conditions
Bejvl, Martin ; Šimek, Petr ; Škramlík, Jiří ; Valouch, Viktor
Current-controlled voltage source converters are widely used in grid-connected applications,for example at ac drives with indirect frequency converters.The structure and parameters of the PLL are developed and proposed in order to cope with the grid containing both the positive and the negative sequence component, and minimize the wrong frequency transients during phase angle steps and also in the start-up stage. The DSC technique was realised. There is also necessary to compensate the negative sequence component in the grid voltage. The negative sequence component of the grid voltage causes ripple of the dc voltage in the intermediate circuit. Several sophisticated topologies of converter current controller were developed, simulated and tested for this purpose. Results of simulation and experimental tests are provided to evaluate different current control schemes and phase locked loop techniques.
|
|
The effect of pressure on the electrode system in lead acid batteries with experimental electrodes
Gerják, Rastislav ; Zimáková, Jana (referee) ; Bača, Petr (advisor)
Lead acid battery is nowadays one of the most used secondary source of energy, especially in automotive industry. One of the most important parameters is battery life, which is result of quality of its design, proper handling and minimizing of degradation mechanisms. This bachelor’s thesis deals with premature capacity loss of lead acid batteries of hybrid electric vehicles in a partial state of charge. Assumed solution is adding additives to negative active mass and suitable adjustment of pressure on the electrode system.
|
|
Mathematical modelling diffusion of metal ions in humic gel
Masár, Lukáš ; Ing. Eva Gregorová,CSc. (referee) ; Klučáková, Martina (advisor)
The subject of this bachelor thesis was simulation of diffusion processes proceeding in the reactive gelous media using the COMSOL Multiphysics software. The aim of this study was to develop a comprehensive set of models available for the interpretation of experimental data obtained in the study of metal ions transport in the humic acids hydrogel. The main consideration was given to the influence of porosity modelling and chemical interactions on the diffusion characteristics (mainly diffusion flow). Within the simulation of the influence of chemical reactions, different kinetic models were used (one-way reaction of first and second order and reverse reaction).
|
guest ::
