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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Nové modifikované nukleosidy s protivirovou nebo cytostatickou aktivitou / Novel modified nucleosides with antiviral or cytostatic activity

Tokarenko, Anna January 2021 (has links)
A general and modular synthetic approach to 4-substituted phenyl, 2-substituted pyridin- 5-yl and 5-substituted pyridin-2-yl 2′-C-methyl-C-ribonucleosides as potential anti-HCV agents was developed. Addition of halo(het)aryllithium reagents to benzylated 2-C-methyl-D- ribonolactone gave the corresponding hemiketals, which were subsequently converted to the β-anomeric benzyl-protected bromo(het)aryl-C-nucleosides via either direct reduction (in the case of phenyl derivative) or acetylation followed by reduction of the resulting hemiketal acetates (in the case of pyridyl derivatives). The key halogenated (het)aryl-C-nucleoside intermediates were further transformed by Pd-catalyzed cross-coupling, hydroxylation and amination reactions affording series of protected C-nucleosides with small hydrophilic and hydrophobic substituents. The final protecting group removal was rather problematic, and different debenzylation methods, such as hydrogenation on Pd/C or treatment with BCl3, had to be optimized for each derivative to minimize the formation of side-products. The final C- nucleosides were also converted into their 5′-O-triphosphates, and biological activity screenings revealed that none of the free C-nucleosides possesses any antiviral activity in the HCV replicon assay, and none of their NTPs...
132

Vývoj instrumentace a metod s vysokou propustností pro hledání a validaci peptidových ligandů / Development of instrumentation and high-throughput screening methods for peptide ligand discovery and validation

Kryštůfek, Robin January 2021 (has links)
Peptides are used as synthetically available and easily derivatizable scaffold upon which it is possible to develop ligands targeting broad spectrum of biological targets. A time-tested approach to peptide binder identification is the preparation and screening of combinatorial libraries. Bypassing of this complicated procedure is possible by using biological systems for presentation, identification and selection of peptides based on the principle of in vitro evolution - i.e. display techniques. There are two complementary automated solutions for peptide binder identification described in this work. First is the SPENSER parallel peptide synthesizer, developed as a part of this diploma project, which can be used for peptide ligand discovery and optimization as well as validation of ligands identified using display techniques. Several libraries consisting of a total of 1 052 peptides have been prepared and then used to describe its potential applications. A sample of 154 preparations, representing 14.6 % analytical coverage of the prepared libraries, showed an average purity of 67 ± 19 % according to LC-MS. The libraries presented illustrate that SPENSER is a suitable tool for the parallel synthesis of linear and disulfide-cyclized peptides with limited variability, or libraries consisting of short...
133

Akcelerace kompresního algoritmu LZ4 v FPGA / Acceleration of LZ4 Compression Algorithm in FPGA

Marton, Dominik January 2017 (has links)
This project describes the implementation of an LZ4 compression algorithm in a C/C++-like language, that can be used to generate VHDL programs for FPGA integrated circuits embedded in accelerated network interface controllers (NICs). Based on the algorithm specification, software versions of LZ4 compressor and decompressor are implemented, which are then transformed into a synthesizable language, that is then used to generate fully functional VHDL code for both components. Execution time and compression ratio of all implementations are then compared. The project also serves as a demonstration of usability and influence of high-level synthesis and high-level approach to design and implementation of hardware applications known from common programming languages.
134

Inovace barvy marimby pomocí nových kamenů, rezonátorů a přidáním virtuálních rejstříků / The innovation of marimba timbre using new bars, resonators, and adding virtual registers

Nop, Patrik January 2019 (has links)
This diploma thesis focuses on suitable innovation of musical instrument marimba. The chosen problem has been verified by three optoins: new bars, new resonators, virtual registers. The work provides an analysis of the whole issue with verification of some samples and their inclusion or exclusion for further use in the research.
135

Fotorealistické zobrazování 3D scén / Photorealistic Rendering of 3D Scenes

Vlnas, Michal January 2020 (has links)
This thesis proposes a concept of sampling, especially for path tracing like algorithms, for faster convergence of the scene, using a local radiance approximation in the scene with hemispherical harmonics, which allows more effective way of ray casting on the given surface. In the first part, the basics of photorealistic rendering are introduced together with commonly used algorithms for image synthesis. The mathematical apparatus used in this thesis is defined in the second part of the thesis. Subsequently, existing solutions in this area are presented. The following chapter summarizes state-of-the-art methods in this branch. The rest of this thesis is focused on proposal and implementation of already mentioned extension.
136

Příprava tobermoritu / Preparation of Tobermorite

Dlabajová, Lucie January 2020 (has links)
This doctoral thesis is focused on the study of reactions in the CaO–SiO2–H2O complex system, primarily to the synthesis of crystalline tobermorite. Hydrothermal conditions are necessary for the formation of crystalline tobermorite, whereas the course of the reaction is influenced by several factors. The main studied factor was the choice of the silica sources differing in means of solubility, crystallinity, particle size distribution, specific surface area, and purity. The water-to-solid ratio turned to be also an important factor as the length of the hydrothermal reaction. The influence of the mechanochemical pretreatment of starting materials to the final phase composition of samples was studied as well. The obtained results show that the crystallinity of the silica source is the main factor influencing the reaction rate and the purity of the synthesized tobermorite. While using the crystalline silica source the shorter silicate chains are formed and the formation of tobermorite structure is easier. Using the amorphous silica sources and the mechanochemical pretreatement of starting materials prolong the hydrothermal reaction. The prepared samples are always the mixture of crystalline or semicrystalline calcium hydrosilicates instead of the phase pure tobermorite.
137

GPU-akcelerovná syntéza pravděpodobnostních programů / GPU-Accelerated Synthesis of Probabilistic Programs

Marcin, Vladimír January 2021 (has links)
V tejto práci sa zoberáme problémom automatizovanej syntézy pravdepodobnostných programov: majme konečnú rodinu kandidátnych programov, v ktorej chceme efektívne identifikovať program spĺňajúci danú špecifikáciu. Aj riešenie tých najjednoduchších syntéznych problémov v praxi predstavuje NP-ťažký problém. Pokrok v tejto oblasti prináša nástroj Paynt, ktorý na riešenie tohto problému používa novú integrovanú metódu syntézy pravdepodobnostných programov. Aj keď sa tento prístup dokáže efektívne vysporiadať s exponenciálnym rastom rodín kandidátnych riešení, stále tu existuje problém spôsobený exponenciálnym rastom jednotlivých členov týchto rodín. S cieľom vysporiadať sa aj s týmto problémom, sme implementovali GPU orientované algoritmy slúžiace na overovanie kandidátnych programov (modelov), ktoré danú úlohu paralelizujú na stavovej úrovni pravdepodobnostých modelov. Celkové zrýchlenie doshiahnuté týmto prístupom za určitých podmienok potom prinieslo takmer teoretický limit možného zrýchlenia syntézneho procesu.
138

Studium přípravy a katalytické aktivity dopovaných ABO3 perovskitů pro syntézu vodíku. / The study of preparation and catalytic activity of doped ABO3 perovskites for hydrogen synthesis

Dobeš, Jiří January 2015 (has links)
The Master´s thesis deals with the preparation of perovskite oxides by glycine synthesis with following characterization and analysis of catalytic activity. Especially is discussed crystallographic structure. In the theoretical part were first summarized the available information of the properties and usage of perovskite oxides. In the experimental part of the work was carried out the preparation of perovskite oxides and were made chemical analysis. Moreover a catalytic activity of selected perovskites has been studied and have been illustrated their crystal structure.
139

Komunikační systémy s digitálními modulacemi / Communication Systems with Digital Modulations

Spáčil, Jan January 2008 (has links)
The purpose of this semestral project is to explain the basic issues of simple digital modulations through the creation of simple digital modulations using direct digital synthesis. It begins with a short review of digital modulation theory and the theory about direct digital synthesis. All the technical documentation is attached, including schematics and boards of functional modulator.
140

Přímý číslicový frekvenční syntezátor / Direct digital frequency synthesizer

Svoboda, Josef January 2009 (has links)
Direct Digital Frequency Synthesis (DDFS) is a method of producing an analog waveform, usually a sine wave, by generating a time varying signal in digital form a then performing a digital to analog conversion. Because operations within a DDFS device are primarily digital, it can offer fast switching between output frequencies, fine frequency resolution and operation over a broad spectrum of frequencies.

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