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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.
191

Podpůrné měniče v elektrické trakci / Auxiliary inverters for electric traction

Polášek, Petr January 2009 (has links)
This thesis concerns with specified problems of an electric traction. It deals with the concept of module controlling EC motor of the voltage 24V and the current 100A. There are described possibilities and principles of controlling EC motor in detail. For controlling, the single-purpose IO MC33035, which is directly specified for it, is used. The thesis describes implementation of both testing and final versions of converter for a circulating pump drive of a cooling circuit in locomotives. The convertor is partly universal and can be used in other applications. According to the implemented convertor, a laboratory test and a model protocol were made. In the second part, the concept is described as well as the implementation of DC/DC conventor of output voltage of 24V and which is supplied by 12V battery. The specified output current is 4A. It is used for supplying of the controlling traction vehicle unit and is installed as a boost convertor which contains a resonance conventor. The presentation of measured parameters of the complete convertor is either a part of this thesis.
192

Zvýšení průtoku chladící vody pro absorpční chladící agregáty ve stanici zdroje chladu na JE Dukovany / Increasing the flow of cooling water for absorption cooling systems in the nuclear power plant Dukovany

Dvořák, Josef January 2015 (has links)
The thesis focuses on comparison of the original and the new solutions of cooling water circuit of the York cooling units for the purpose of cooling water flow increase for the absorption units in the Dukovany Nuclear Power Plant. The individual parts of the cooling units that were changed and modified within a reconstruction are described here. The aim of the work is also to process and compare the original and the new solutions of the cooling units and the cold source station from the available measured data. The data are processed into illustrative graphs and tables. Based on the obtained data we can observe the changes achieved by the reconstruction that have affected the effectiveness of the cooling units.
193

Laboratorní diagnostiky mikrometastáz u pacientek s karcinomem prsu / Laboratory diagnostics of micrometastases in breast cancer patients

Mikulová, Veronika January 2016 (has links)
Introduction: The presence of circulating tumor cells (CTC) in the peripheral blood has been associated with worse prognosis and early relapse in breast cancer patients. CTC determination in the peripheral blood has been considered as a liquid biopsy. The aim of this project was to analyze the presence of CTC followed by their molecular characterization with the potential use not only as a new biomarker for real-time monitoring of therapy efficacy but also as a suitable tool for patient's stratification and individualization of treatment for breast cancer. Methods: A total of 54 patients with diagnosed early breast cancer were enrolled into a prospective study. Ten millilitres of peripheral blood were sequentially collected to test for the presence and characterization of CTC during the follow-up of patients. CTC isolation and detection was performed by AdnaTest BreastCancer™ (AdnaGen AG, Germany), which is based on the detection of EpCAM, HER2 and MUC1 specific transcripts in enriched CTC- lysates. cDNA from isolated CTC has been further used for newly optimized qPCR assays for breast tumor and therapy resistance associated genes: TOP1, TOP2A, CSTD, ST6GAL, KRT19 and reference gene actin. qPCR results have been analyzed by Genex software (MultiD Analysis). Results: 195 blood samples have been...
194

Multimarker Gene Analysis of Circulating Tumor Cells in Pancreatic Cancer Patients: A Feasibility Study

de Albuquerque, Andreia, Kubisch, Ilja, Breier, Georg, Stamminger, Gudrun, Fersis, Nikos, Eichler, Astrid, Kaul, Sepp, Stölzel, Ulrich January 2012 (has links)
Objective: The aim of this study was to develop an immunomagnetic/real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay and assess its clinical value for the molecular detection of circulating tumor cells (CTCs) in peripheral blood of pancreatic cancer patients. Methods: The presence of CTCs was evaluated in 34 pancreatic cancer patients before systemic therapy and in 40 healthy controls, through immunomagnetic enrichment, using the antibodies BM7 and VU1D9 [targeting mucin 1 and epithelial cell adhesion molecule (EpCAM), respectively], followed by real-time RT-PCR analysis of the genes KRT19, MUC1, EPCAM, CEACAM5 and BIRC5. Results: The developed assay showed high specificity, as none of the healthy controls were found to be positive for the multimarker gene panel. CTCs were detected in 47.1% of the pancreatic cancer patients before the beginning of systemic treatment. Shorter median progression-free survival (PFS) was observed for patients who had at least one detectable tumor-associated transcript, compared with patients who were CTC negative. Median PFS time was 66.0 days [95% confidence interval (CI) 44.8–87.2] for patients with baseline CTC positivity and 138.0 days (95% CI 124.1–151.9) for CTC-negative patients (p = 0.01, log-rank test). Conclusion: Our results suggest that in addition to the current prognostic methods, CTC analysis represents a potential complementary tool for prediction of outcome in pancreatic cancer patients. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
195

Multimarker Analysis of Circulating Tumor Cells in Peripheral Blood of Metastatic Breast Cancer Patients: A Step Forward in Personalized Medicine

Albuquerque, Andreia de, Kaul, Sepp, Breier, Georg, Krabisch, Petra, Fersis, Nikos January 2012 (has links)
Aim: To develop an immunomagnetic assay for the isolation of circulating tumor cells (CTCs) followed by the analysis of a multimarker panel, which will enable the characterization of these malignant cells with high accuracy. Patients and Methods: Peripheral blood (PB) was collected from 32 metastatic breast cancer patients and 42 negative controls. The antibodies BM7 and VU1D9 were used for immunomagnetic tumor cell enrichment. A real-time reverse transcription-polymerase chain reaction (RT-PCR) approach for the markers KRT19, SCGB2A2, MUC1, EPCAM, BIRC5 and ERBB2 was used for CTC detection and characterization. Results: The positivity rates for each marker were as follows: 46.9% for KRT19, 25.0% for SCGB2A2, 28.1% for MUC1, 28.1% for EPCAM, 21.9% for BIRC5, and 15.6% for ERBB2. After the creation of individualized cutoffs, the sensitivity and specificity of the combined marker gene panel increased to 56.3% and 100%, respectively. Interestingly, 27.0% of the HER2-negative tumor patients showed ERBB2 mRNA-positive CTCs. Conclusions: The described technique can be used to measure CTCs with great accuracy. The use of a multimarker panel for the characterization of CTCs may provide real-time information and be of great value in therapy monitoring. / Ziel: Entwicklung eines immunomagnetischen Verfahrens zur Isolierung zirkulierender Tumorzellen (CTCs) in Kombination mit einer molekularen Multimarkeranalyse für die hochspezifische Identifizierung maligner Zellen. Patientinnen und Methoden: Peripheres Blut (PB) von 32 Patientinnen mit metastasiertem Mammakarzinom und von 42 gesunden Kontrollen wurde für die immunomagnetische Tumorzellanreicherung mit den Antikörpern BM7 und VU1D9 genutzt. Eine Real-Time Reverse Transkription Polymerase-Kettenreaktion (RT-PCR)-Methodik mit den Markern KRT19, SCGB2A2, MUC1, EPCAM, BIRC5 und ERBB2 wurde für den CTC-Nachweis und die Tumorzellcharakterisierung entwickelt. Ergebnisse: Für die einzelnen Marker wurden die folgenden Positivitätsraten ermittelt: 46,9% für KRT19, 25,0% für SCGB2A2, 28,1% für MUC1, 28,1% für EPCAM, 21,9% für BIRC5 und 15,6% für ERBB2. Nach der Bestimmung individualisierter Cut-off-Werte ergab sich für den kombinierten Multimarkernachweis eine Sensitivität und Spezifität von 56,3% bzw. 100%. Bemerkenswert war der Befund, dass 27,0% der HER2-tumornegativen Patientinnen ERBB2-mRNA-positive CTCs aufwiesen. Schlussfolgerung: Die hier beschriebene Methodik bestimmt CTCs mit hoher Spezifität. Die molekulare Multimarkeranalyse liefert wertvolle Real-Time-Informationen für personalisierte Behandlungsmodalitäten. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
196

Operation of Parallel Connected Converters as a Multilevel Converter

Kannan, Vijay 11 January 2018 (has links)
The still increasing demand of electrical energy and the rising popularity of renewable energy sources in today's world are two important developments that necessitate the need for innovative solutions in the field of power electronics. Parallel operation of converters is one possible method in trying to bridge an increased current demand. The classical two-level converters, which are the standard in low voltage applications, are rarely adopted in medium and high voltage applications due to the voltage limits on power semiconductor devices. That is one reason for the growing popularity of multilevel converter topologies in medium and high-voltage applications. Although an increase in the number of voltage levels of a multilevel converter has its advantages, there are also challenges posed due to the increased number of switching devices. This has resulted in three-level converters being the most popular compared to converters of higher voltage levels. In this dissertation, the unified operation of parallel connected three-level converter units as a multilevel converter of higher voltage levels is proposed. The mathematical basis for operating parallel connected converter units as a single multilevel converter and the governing equations for such systems are derived. The analysis and the understanding of these equations are important for assessing practicality of the system and devising appropriate control structures. Parallel operation of converter units operating as multilevel converter have their own set of challenges, the two foremost being that of load-sharing and the possibility of circulating and cross currents. Developing solutions to address these challenges require a thorough understanding of how these manifest in the proposed system. Algorithms are then developed for tackling these issues. The control structures are designed and the developed algorithms are implemented. The operation of the system is verified experimentally. / Die weiterhin steigende Nachfrage nach elektrischer Energie und die zunehmende Verwendung erneuerbarer Energiequellen in der heutigen Welt sind zwei wichtige Entwicklungen, die die Notwendigkeit innovativer Lösungen im Bereich der Leistungselektronik erfordern. Der Parallelbetrieb von Stromrichtern ist eine mögliche Methode, um einen erhöhten Strombedarf zu decken. Der klassische Zweipunkt-Spanungszwischenkreisstromrichter, der bei Niederspannungsanwendungen weit verbreitet ist, wird aufgrund der Spannungsgrenzen für Leistungshalbleiterbauelemente zunehmend weniger in Mittel- und Hochspannungsanwendungen eingesetzt. Die begrenzte Spannungsbelastbarkeit der Leistungshalbleiterbauelemente ist ein Grund für die wachsende Beliebtheit von Mehrpunkt-Stromrichtertopologien in Mittelund Hochspannungsanwendungen. Obwohl eine Erhöhung der Anzahl der Spannungsstufen eines Mehrpunkt-Stromrichters Vorteile hat, gibt es auch Herausforderungen und Nachteile aufgrund der erhöhten Anzahl von Leistungshalbleitern. Dies hat dazu geführt, dass der Dreipunkt-Stromrichter die verbreiteste Topologie im Vergleich zu anderen Stromrichtern mit einer höheren Anzahl von Spannungsstufen ist. In dieser Dissertation wird der Betrieb von parallel geschalteten Dreipunkt-Stromrichtereinheiten als ein Mehrpunkt-Stromrichter mit erhöhter Anzahl an Spannungsstufen vorgeschlagen. Die mathematische Basis für den Betrieb von parallel geschalteten Stromrichtereinheiten als ein Mehrpunkt-Stromrichter und die beschreibenden Gleichungen eines solchen Systems werden abgeleitet. Die Analyse und das Verständnis dieser Gleichungen sind wichtig für die Beurteilung der Praktikabilität des Systems und die Erarbeitung geeigneter Regelstrukturen. Der parallele Betrieb von Stromrichtereinheiten hat seine eigenen Herausforderungen, wobei die beiden wichtigsten die Lastverteilung und die Möglichkeit von Kreis- und Querströmen sind. Die Entwicklung von Lösungen zur Bewältigung dieser Herausforderungen erfordert ein gründliches Verständnis dafür, wie sich diese Phänomene in dem vorgeschlagenen System manifestieren. Algorithmen zur Lösung dieser Probleme werden anschlieend entwickelt. Die Regelstrukturen werden entworfen und die entworfenen Algorithmen implementiert. Die Funktionsweise des Systems wird experimentell überprüft.
197

Možnosti predikce a imunointervence u diabetu 1. typu / Possibilities of prediction and immunointervention in type 1 diabetes

Sklenářová, Jana January 2020 (has links)
Type 1 diabetes mellitus (T1D) is an organ-specific autoimmune disease characterised by autoimmune destruction of insulin-producing beta cells in the islets of Langerhans. It is a long-term process initiated months or even years prior to the clinical onset. The main role in the pathogenesis is played by T lymphocytes but other cell types are involved as well. The presence of autoantibodies in the circulation is typical even before the disease onset. Nowadays, intensive research is focused on finding individuals at risk and developing an effective prevention. During my postgraduate studies I was involved mainly in the research of T1D prediction and prevention. We investigated the relationship of established autoimmune markers - autoantibodies - and the cellular reactivity to GAD65 and IA2 autoantigens. We discovered that the reaction to autoantigens is very individual and it is influenced by the patient's autoantibody profile. These results could be relevant in planning antigen-specific immunointervention studies and improving their efficacy. We also made an attempt to improve specificity and sensitivity of a beta cell destruction marker (specifically demethylated DNA), which would enable better understanding of the beta cell decline and identification of individuals at risk of T1D development. In...
198

Affinity Based Capture of Circulating Tumour Cells Using Designed Ankyrin Repeat Proteins (DARPins) in a Microfluidic System

Spåre, Emil January 2021 (has links)
Designade ankyrinupprepningsproteiner (DARPiner) är små, mycket stabila antikroppsmimetiska proteiner. I det här projektet användes anti-EpCAM-DARPiner tillsammans med mikrofluidik för att avgära om de kunde fånga upp HCT116-celler mer effektivt än anti-EpCAM-antikroppar. Ytorna på insidan av mikroffluidikkanaler förändrades genom bindning av N-γ-maleimidobutyryl-oxysuccinimidester (GMBS) och merkaptopropyltrietoxysilan (MPTES) för anti-EpCAM-antikroppar och GMBS och (3-aminopropyl)trietoxysilan (APTES) för DARPiner. Båda kanaltyperna testades genom inflöde av cancerceller och helblod blandat med cancerceller. Ingen effektiv och konsekvent celluppfångst åstadkoms trots att det visades att antikropparna och DARPinerna kunde binda till cellerna direkt och att test med fluorescenta DARPiner och antikroppar visade att ytförändringskemin var fungerande. Slutsatsen blev att de mest troliga orsakerna till misslyckandena var att ytförändringskemin påverkade proteinernas bindningsförmåga negativt eller att proteinerna bands till kanalernas yta i fel riktning. DARPiner är fortfarande intressanta för tillämpningar inom mikrofluidik, men vidare förbättring av det experimentella protokollet behövs. / Designed ankyrin repeat proteins (DARPins) are small and highly stable antibody mimetics. In this project, anti-EpCAM DARPins were used in conjunction with microfluidics to determine if they could capture HCT116 cells more effectively than anti-EpCAM antibodies. The inside surfaces of microfluidic chips were modified using N-γ-maleimidobutyryl-oxysuccinimide ester (GMBS) and mercaptopropyltriethoxysilane (MPTES) for anti-EpCAM antibodies, and surface modifications for anti-EpCAM DARPins were made using GMBS and (3-aminopropyl)triethoxysilane (APTES). Both chip types were tested using cancer cells and whole blood mixed with cancer cells. No effective and consistent cell capture was achieved, despite the antibodies and DARPins being shown to be able to bind to the cells directly and tests with fluorescently labelled DARPins and antibodies showing that the surface modification chemistry used was functional. It was concluded that the most likely causes of the failures were surface modifications interfering with the binding ability of the proteins, or improper orientation of the bound proteins. The DARPin remains a protein of interest for microfluidic applications, but further changes and optimisation of the experimental protocol is necessary.
199

Laboratorní diagnostiky mikrometastáz u pacientek s karcinomem prsu / Laboratory diagnostics of micrometastases in breast cancer patients

Mikulová, Veronika January 2016 (has links)
Introduction: The presence of circulating tumor cells (CTC) in the peripheral blood has been associated with worse prognosis and early relapse in breast cancer patients. CTC determination in the peripheral blood has been considered as a liquid biopsy. The aim of this project was to analyze the presence of CTC followed by their molecular characterization with the potential use not only as a new biomarker for real-time monitoring of therapy efficacy but also as a suitable tool for patient's stratification and individualization of treatment for breast cancer. Methods: A total of 54 patients with diagnosed early breast cancer were enrolled into a prospective study. Ten millilitres of peripheral blood were sequentially collected to test for the presence and characterization of CTC during the follow-up of patients. CTC isolation and detection was performed by AdnaTest BreastCancer™ (AdnaGen AG, Germany), which is based on the detection of EpCAM, HER2 and MUC1 specific transcripts in enriched CTC- lysates. cDNA from isolated CTC has been further used for newly optimized qPCR assays for breast tumor and therapy resistance associated genes: TOP1, TOP2A, CSTD, ST6GAL, KRT19 and reference gene actin. qPCR results have been analyzed by Genex software (MultiD Analysis). Results: 195 blood samples have been...
200

Detekce minimální reziduální choroby v kostní dřeni a periferní krvi u pacientek s karcinomem prsu. / Detection of minimal residual disease in bone marrow an peripheral blood in patients with breast cancer.

Čabiňaková, Michaela January 2015 (has links)
Introduction: Simultaneous detection of disseminated tumor cells (DTCs) and circulating tumor cells (CTCs) was shown to be associated with an especially poor prognosis and increased incidence of disease-related deaths in non-metastatic breast cancer patients. We analyzed the occurance of DTCs in bone marrow and CTCs in peripheral blood in patients with primary breast cancer, we evaluated the correlation of their presence with other prognostic markers and we investigated the changes in DTCs/CTCs number at different time points during treatment. Materials and methods: Blood of 50 patients with primary breast cancer were used for immunomagnetic separation and detection of circulating tumor cells using the commercial available system the AdnaTest Breast Cancer™ (AdnaGen GmbH, Langenhagen, Germany). Bone marrow aspirates from 50 patients were analyzed for DTCs by immunocytochemistry using the pancytokeratin antibody conjugated with FITC (Monoclonal Anti-Cytokeratin antibody F3418, Sigma Aldrich, USA). Results: DTCs were identified in 30% (15/50) and CTCs in 22% (11/50) of patients. We found that DTC positivity could point to a significantly high risk of larger primary tumor size (p- value 0.011) and significantly higher risk of lymph node involvement (p- value 0.002). For CTC positivity, no such...

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