• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 110
  • 32
  • 1
  • 1
  • 1
  • Tagged with
  • 145
  • 124
  • 90
  • 88
  • 38
  • 21
  • 20
  • 19
  • 18
  • 17
  • 15
  • 15
  • 15
  • 14
  • 13
  • 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.
101

Meření CP narušení na experimentu Belle v rozpadech B0 → ŋcK0S metodou tzv. časové analýzy, optimalizace vrcholového detektoru pro expriment Belle II. / Measurement of Time-Dependent CP Violation in B0 → ŋcK0S at Belle Experiment, Optimization Studies of the Belle II Vertex Detector

Drásal, Zbyněk January 2014 (has links)
Title: Measurement of Time-Dependent CP Violation in B0 → ηcK0 S at Belle Experi- ment, Optimization Studies of the Belle II Vertex Detector Author: Zbyněk Drásal Department: Institute of Particle and Nuclear Physics Supervisor: Dr. Zdeněk Doležal, IPNP Supervisor's e-mail address: Zdenek.Dolezal@mff.cuni.cz Abstract: This doctoral thesis deals with two independent topics. In the first part we present a measurement of branching ratio(s) and time-dependent CP violation parame- ters in B0 (B± ) → ηcK0 S(K± ), ηc → p¯p. The values of CP violation parameters have been found as follows: sin 2φ1, denoted as an SCP parameter, equals: SCP = 0.68+0.38 −0.46±0.13syst, the direct CP violation parameter, denoted as an ACP , is: ACP = 0.00+0.23 −0.31 ± 0.08syst. These results have been obtained with the final data sample of 772×106 B ¯B pairs collected at Υ(4S) resonance with a Belle detector at the KEKB e+ e− asymmetric collider machine in Japan. In the second part, we present our approach to the Monte Carlo (MC) simula- tion of Belle II vertex detector and its response to high energy particles. Belle II represents an upgrade of current Belle experiment and its designed vertex detector will consist of 2 layers of Depfet pixel detectors (PXD) and 4 layers of double-sided silicon micro-strip detectors (SVD). The MC...
102

Diagnostický příspěvek k hodnocení intervenčních modelů léčby diabetu mellitu 1. typu / Diagnostic contribution to the evaluation of intervention models in the treatment of type 1 diabetes

Zacharovová, Klára January 2012 (has links)
During treatment of diabetes mellitus by immunointervention or transplantation, it is necessary to monitor the markers of immune destruction or rejection of surviving insulin producing cells. An aim of this thesis is to improve the possibilities of following autoimmunity and to detect the survival of transplanted pancreatic islet in vivo. Partial aims included vitality testing of isolated islets for transplantation by measurement of respiration activity, observing the process of in vitro labeling of isolated islets with superparamagnetic iron oxide (SPIO) contrast agent for subsequent magnetic resonance imaging (MRI) of islets and observing SPIO particles transport after transplantation. We also studied a new dual paramagnetic contrast agent combined with fluorescein intended for identification of the MRI contrast agent in samples for histology. Further, we assessed autoimmune reaction by evaluation of cytokine response to specific stimulation with auto-antigens. We tried to affect beta-cells destruction by polyclonal anti- thymocyte antibodies in a mouse experimental model. A new method of the islet respiration measurement correlated with other methods of islet quality testing and it was suggested as a diagnostic test before clinical transplantation. Results obtained studying the intercellular...
103

Neuromodulace v léčbě vybraných dystonických syndromů / Neuromodulation in treatment of selected dystonic syndromes

Havránková, Petra January 2011 (has links)
Dystonia is a neurological syndrome characterized by the involuntary contraction of opposing muscles, causing twisting movements or abnormal postures (modified by Fahn, 1987). Writer's cramp is the most common form of task-specific focal dystonia. In the first study, patients with writer's cramp were evaluated for differences in cortical activation during movements likely to induce cramps (complex movements) and movements which rarely lead to dystonia (simple movements). Although complex patient movements during fMRI were never associated with dystonic cramps, they exhibited abnormally decreased cortical activity. This was not observed in simple movements and was unrelated to the character of handwriting or the presence/absence of visual feedback. Our results support the theory of dualistic sensorimotor system behavior in writer's cramp. As the somatosensory system is believed to be affected in focal dystonia, we focused on modulation of the primary somatosensory cortex (SI) induced by repetitive transcranial magnetic stimulation (rTMS) in the second study, in order to improve writer's cramp. In conclusion, 1 Hz rTMS of the SI cortex can improve manifestations of writer's cramp while increasing cortical activity in both hemispheres. Handwriting as well as subjective assessment improved in most...
104

Charakterizace glykoforem haptoglobinu v lidském séru / Characterization of hapt oglobin glycoforms in human serum

Darebná, Petra January 2015 (has links)
Characterization of haptoglobin glycoforms in human serum Petra Darebná (Katedra biochemie, Přírodovědecká fakulta, Univerzita Karlova v Praze, Česká republika) Changes in glycosylation of proteins are associated with several types of cancer, including hepatocelular carcinoma and colorectal carcinoma. This project deals with data independent analysis using ion cyclotron resonance with Fourier transform and tandem mass spectrometry with liquid chromatogramy and multiple reaction monitoring to quantify these changes in hepatocelular cancinoma and colorectal carcinoma with liver metastases. In the first part of the project the haptoglobin was enriched from pooled serum samples of pacients with hepatocellular carcinoma, colorectal cancer and colorectal carcinoma with metastases using hemoglobin immobilized on CNBr-activated Sepharose 4B and then purified by high pressure liquid chromatography. Individual haptoglobin glycopeptides were analyzed using ion cyclotron resonance with Fourier transform. In the second part of the project we analyzed changes in glycosylation depending on diferent tumor diseases in partially depleted serum of individual patients using ethanol precipitation. Individual fucosylated glycoforms of N-glycopeptides of serum proteins were compared with their nonfucosylated forms. In...
105

Stabilita a vlastnosti kombinovaných nápojů a ovocných koncentrátů / Stability and properties of combined beverages and fruit concentrates

Klatová, Kamila January 2018 (has links)
This diploma thesis deals with the stability and basic properties of combined beverages and fruit concentrates. The theoretical part describes the production and use of fruit concentrates. Furthermore, the work deals with anthocyanic pigments and phenolic substances. The principle and instrumentation of liquid chromatography and electron paramagnetic resonance were described. In the next subchapter, the methods of determination of total anthocyanins and phenolic substances were described. The experimental part of the thesis described the determination of soluble solids, viscosity and antioxidant activity. The total content of phenolic compounds were determined by the Folin-Ciocalteua method and the total anthocyanins were determined by the pH-differential method. In the samples were determined cyanidine-3-glucoside and cyanidin-3-galactoside by liquid chromatography.
106

Vzájemná interakce tlakových pulsací a kmitání nepřímé trubice / Mutual interaction of pressure pulsations and pulsations of undirect pipe

Hrazdíra, Zdeněk January 2018 (has links)
This thesis deals with mathematical modeling of multiphysics FSI (fluid-structure interaction) problem, describing mutual interaction of pressure pulsations and vibrations of indirect pipe in a 2D region. Firstly, physical partial differential equations are derived separately for both media, which are in turn coupled and solved analytically. Results of mentioned models include natural frequency values, amplitude-frequency characteristics and both natural and driven damped oscillations of pipe and liquid.
107

Excitace a šíření spinových vln v magnonických krystalech připravených přímým zápisem fokusovaným iontovým svazkem / Spin wave excitation and propagation in magnonic crystals prepared by focused ion beam direct writing

Křižáková, Viola January 2018 (has links)
Paramagnetické niklem stabilizované tenké vrstvy plošně centrovaného kubického Fe, epitaxně narostené na monokrystalickém substrátu Cu(100) jsou známy svou schopností strukturní a magnetické fázové přeměny při ozáření iontovým svazkem, a to do prostorově centrované kubické struktury charakteristické feromagnetickými vlastnostmi. Monokrystalický Cu(100) substrát je možné také nahradit Si(100) s mezivrstvou Cu(100). Pomocí fokusovaného iontového svazku lze dále snadno lokálně modifikovat magnetické vlastnosti ozařované vrstvy. Tato metoda přímého zápisu magnetických struktur je alternativou k běžným litografickým technikám, nabízející nové jimi nedosažitelné možnosti. Připravené magnetické struktury následně využíváme k propagaci spinových vln. V práci je představen celý proces od růstu vrstev, přes přípravu mikrostruktur, až po studium jejich struktury a statických i dynamických magnetických vlastností. S využitím vektorového síťového analyzátoru studujeme ve vrstvách a v mikrostrukturách připravených fokusovaným iontovým svazkem feromagnetickou rezonanci a propagující se spinové vlny. Zdrojem spinových vln o definovaných vlnových vektorech jsou litograficky připravené koplanární vlnovody, sloužící také k induktivní detekci vln. Pomocí feromagnetické rezonance kvantitativně určujeme materiálové charakteristiky jako jsou saturační magnetizace a parametr útlumu a ze spekter propagujících módů následně určujeme charakteristiky spinových vln, které porovnáváme s dalšími feromagnetickými materiály.
108

Pokročilé metody perfuzní analýzy v MRI / Advanced Methods of Perfusion Analysis in MRI

Macíček, Ondřej January 2020 (has links)
This dissertation deals with quantitative perfusion analysis of MRI contrast-enhanced image time sequences. It focuses on two so far separately used methods -- Dynamic contrast-enhanced MRI (DCE-MRI) and Dynamic susceptibility contrast MRI (DSC-MRI). The common problem of such perfusion analyses is the unreliability of perfusion parameters estimation. This penalizes usage of these unique techniques on a regular basis. The presented methods are intended to improve these drawbacks, especially the problems with quantification in DSC in case of contrast agent extravasation and instability of the deconvolution process in DCE using advanced pharmacokinetic models. There are a few approaches in literature combining DCE and DSC to estimate new parameters of the examined tissue, namely the relaxivity of the vascular and of the interstitial space. Originally, in this scheme, the 2CXM DCE model was used. Here various models for DCE analysis are tested keeping in mind the DCE-DSC combination. The ATH model was found to perform better in this setting compared to 2CXM. Finally, the ATH model was used in alternating DCE-DSC optimization algorithm and then in a truly fully simultaneous DCE-DSC. The processing was tested using simulated and in-vivo data. According to the results, the proposed simultaneous algorithm performs better in comparison with sequential DCE-DSC, unleashing full potential of perfusion analysis using MRI.
109

Vliv vodivých vzorků na vznik deformací vf magnetického pole / Impact of conductive material on RF magnetic field deformation

Vondra, Petr January 2009 (has links)
The work analyses formation of deformations of RF magnetic field within the environment of electrically and magnetically conductive materials. An analytic solution of the problem is created and the problems of numerical modeling are solved. In theoretical way, the work also familiarize with the use of magnetic resonance imaging method - the spin echo method (SE), with its features and possibilities of its use within the aim of the project. This method is used for experimental measurements of electrically conductive materials in the NMR laboratory in ISI AV Czech Republic. Results of the simulation are compared with results of the experimental measurement.
110

Magnetická pole pro biomedicínské experimenty / Magnetic fields for biomedical experiments

Otýpka, Jan January 2010 (has links)
In this work deals with magnetic fields for use in biomedicine. This solution involves the choice of the correct geometric arrangement of coils for generating magnetic field with a homogeneous distribution of magnetic induction of the widest possible area. The paper compares thre traditional types of coils, solenoid, toroid and Helmholtz coil. For Helmholtz and solenoid coil and is then carried out an analysis of the magnetic flux density in the inner space. Next part is devoted to electrical resonance in the LC circuit. This is then utilized for the development of pulsed magnetic field in the Helmholtz coil. It summarizes the theoretical and practical knowledge to design and construction of resonant converters. The end is devoted to the measurement of circuit parameters and verification of theoretical knowledge.

Page generated in 0.0767 seconds