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Testung verschiedener Strategien für die Regeneration von Knorpeldefekten im Ex vivo-Testsystem / Evaluation of cartilage regeneration strategies in an osteochondral ex vivo cartilage defect modelBuss, Alexa January 2021 (has links) (PDF)
Die Degeneration des Gelenkknorpels ist Hauptursache für chronische Schmerzen und eine dadurch bedingte Einschränkung der Lebensqualität. Für die Sozialversicherungssysteme ist dies mit steigenden Kosten verbunden. Gegenwärtige Behandlungsoptionen wie die Mikrofrakturierung oder die (matrix-assoziierte) Autologe Chondrozytentransplantation (M-) ACT führen zu einem minderwertigen Reparaturgewebe aus Faserknorpel mit unzureichenden mechanischen Eigenschaften an der Defektstelle. Es besteht ein Bedarf an der Entwicklung und Testung neuer Knorpeltherapien, die ein funktionelles Reparaturgewebe für nachhaltige Beschwerdefreiheit erzeugen. Das hier verwendete kürzlich etablierte osteochondrale Ex vivo-Testsystem (EVTS) eignet sich zur Evaluation unterschiedlicher zellbasierter Behandlungsansätze für die Knorpelregeneration.
Aus der medialen Femurkondyle von Schweinen wurden zylindrische 8 mm große osteochondrale Explantate (OCE) isoliert. Es wurden Knorpel-Knochendefekte und reine Knorpeldefekte kreiert und mit autologen Schweine-Chondrozyten (CZ) bzw. einer Mischung aus CZ und mesenchymalen Stammzellen (MSC) gefüllt, die in Kollagen Typ I Hydrogel eingebettet waren. Nach vierwöchiger Kultivierung wurden die Proben histologisch und immunhistochemisch gefärbt (Safranin-O-Färbung, Kollagen Typ II, Aggrekan), die Zellvitalität (Lebend-Tot-Färbung) überprüft und die extrazelluläre Matrixproduktion analysiert. Nach vierwöchiger Kultur im EVTS in Normoxie und Hypoxie zeigten sich die in Kollagen-I-Hydrogel eingebetteten Zellen lebensfähig. Die Auswertung der verschiedenen Ansätze erfolgte über den standardisierten ICRS-II-Score der International Cartilage Repair Society (ICRS) mit drei unabhängigen Bewertern. Insgesamt resultierten bessere Ergebnisse im Hinblick auf die Matrixsynthese in den Monokulturen aus CZ im Vergleich zu den Co-Kulturen aus CZ und MSCs. Da dieser Unterschied nicht groß war, könnten MSCs zur Einsparung autologer CZ eine Alternative in der Behandlung von Knorpeldefekten darstellen. Hypoxie spielte eine Rolle bei reinen Knorpeldefekten, nicht bei Knorpel-Knochendefekten. Dies bestätigt die Bedeutung des physiologischen hypoxischen Milieus des Gelenkknorpels, das einen niedrigen Sauerstoffgehalt von 2-5
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% aufweist. Die Ergebnisse zeigen, dass die unterschiedlichen Faktoren aus Zellkombination, Knorpeldefektgröße und Kultivierung in Hypoxie oder Normoxie Einfluss auf die Ausbildung der extrazellulären Matrix haben. Weiterhin fehlt jedoch das Verständnis für die genauen Mechanismen des Knorpelregenerationsverhaltens. Ex vivo-Testsysteme können dabei helfen ein weiteres Verständnis zu erlangen und entsprechende Behandlungsstrategien zu evaluieren. / Degeneration of articular cartilage is a major cause of chronic pain - impairing the quality of life and rising health care costs. Current treatment options like microfracture, ACT or MACT result in fibrocartilaginous repair tissue with insufficient mechanical properties at the defect site. Hence, new cartilage therapies generating functional repair tissue need to be developed and tested. Here we used a recently established ex vivo osteochondral model to evaluate the therapeutic potential of several cell-based cartilage regeneration approaches.
Reproducible cylindrical 8 mm osteochondral explants (OCE) were isolated from porcine medial condyles. Full-thickness and cartilage-only defects were created and filled with autologous porcine chondrocytes respectively a mixture of chondrocytes and mesenchymal stem cells, embedded in collagen type I hydrogel. After static culture for four weeks, samples were analyzed for cell viability (live/dead staining) and extracellular matrix production, using immunohistochemical staining (Safranin-O-staining, collagen type II, aggrecan).
Embedded cells remain viable after four weeks culture in ex vivo osteochondral model. Outcome of different cartilage regeneration approaches were compared using the recommended guidelines proposed by the International Cartilage Repair Society (ICRS) and ICRS-II-score with three independent evaluators. Overall, the monocultures from CZ performed better than the co-cultures from CZ and MSCs. Since this difference was not large, MSCs could be an alternative in the treatment of cartilage defects to save autologous CZ. Hypoxia played a role in pure cartilage defects, but not in cartilage-bone defects. This confirms the importance of the physiological hypoxic milieu of the articular cartilage, which has a low oxygen content of 2-5 %. The results show that the different factors from cell combination, cartilage defect size and cultivation in hypoxia or normoxia influence the formation of the extracellular matrix. However, there is still no understanding of the exact mechanisms of cartilage regeneration behavior. Ex vivo test systems can help to gain further understanding and to evaluate appropriate treatment strategies.
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Design and Research of a FPGA Based Universal Liquid Crystal Display Module Function Test SystemYao, Cheng-liang 12 August 2007 (has links)
The subject of this paper is to the research and develop Liquid Crystal Display Module(LCM) test system for LCM factories.We prpose an FPGA,built in an NiosII soft CPU,as the control core with peripheral circuits to form a flexible SOPC¡]System on Programmable Chip¡^. Using this digital circuit being synthetic with the hardware description language, one can further integrate analog and digital peripheral devices by software control to establish a universal of medium and small LCM tester, and can conduct display function verification on such system. This system has been proved effectively to perform functional test for multi type LCM, and meanwhile it further demonstrates the advantage in its flexibility for configuration change due to its SOPC design.
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Evaluation of FPGA based Test SystemsStavström, Marcus January 2015 (has links)
This master thesis report covers an investigation of how FPGA based hardware can be used to create customizable measurement instruments, for test of electrical equipment in JAS 39 Gripen. The investigation is done at Saab Support and Services in Arboga. Electrical equipment are gradually replacing functions, which previously have been obtained by other systems, in safety critical environments. Since the functions are safety critical, they require regular testing in order to verify proper operation. The aircraft JAS 39 Gripen, which is manufactured and developed by Saab, is an example of such system. Proper operation of the avionics in it are essential in order to maintain flying safety. There already exist systems today that can verify the functionality of electronics in JAS 39 Gripen. However, there are a number of scenarios where those test systems are somewhat inflexible. More flexible test systems are often desired. This flexibility can be obtained by using congurable hardware, suggestively with FPGAs. This approach is investigated in this master thesis.
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Testsystem av kontrollsystem för klystronmodulatorer / Test system of the control system of klystron modulatorsFällman, Oscar, Jönsson, Daniel January 2016 (has links)
The company, ScandiNova Systems, has had a need for a test system that can automate and optimize fault detection of the digitizer circuit in the control system of their klystron modulators. This thesis work is intended for this need with the aim of constructing a test system built in LabVIEW, and a pulse generator to generate stimulation for the digitizer circuit board. The test system has been tested and the results have shown that it works well for the given circumstances. The analysis of how the digitizer circuit reads an analog signal works almost perfectly, given an 5%-tolerance interval from the reference value of how the pulse should be. However, not all of the digital outputs of the digitizer can be checked for faults with the current configuration of the circuit board. If the FPGA-code on the digitizer circuit is revised with the pulses of the pulse generator the Boolean error outputs of the FPGA can be correctly checked. If a test system is to be created for other circuits in the control system based on the work done in this thesis project, the parts specified for the present circuit shall be removed from the LabVIEW-program. For example, almost all parts of the GUI that are specified for the digitizer circuit, the stepping of the DIP-switches etc,, shall be removed. Stimuli for the circuits shall also be created according to their specifications.
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The Design and Construction of a UHV Test System to Evaluate A Magnetron Pump-Gauge (Part B)Cuthbert, John Richard 09 1900 (has links)
Second project report of two. Part A is available at http://hdl.handle.net/11375/17551 / <p> The design, construction, and initial operation of an ultra high vacuum testing system was undertaken. The final UHV system is equipped with a residual gas analyser (RGA). </p> <p> The system was used to test a National Research Council of Canada magnetron pump-gauge. The pumping action of the device was adequate with speeds of litres/second for hydrogen and other chemically active species. A speed of ≃0.3 L/S was measured for methane (CH₄). The pressure measuring capabilities of this particular pump may be in question due to the presence of surface leakage currents. </p> / Thesis / Master of Engineering (ME)
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Advanced Test Range Verification at RF Without FlightsWilliams, Steve 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / Flight and weapons test ranges typically include multiple Telemetry Sites (TM Sites) that receive telemetry from platforms being flown on the range. Received telemetry is processed and forwarded by them to a Range Control Center (RCC) which is responsible for flight safety, and for delivering captured best source telemetry to those responsible for the platform being flown. When range equipment or operations are impaired in their ability to receive telemetry or process it correctly, expensive and/or one-of-a-kind platforms may have to be destroyed in flight to maintain safety margins, resulting in substantial monetary loss, valuable data loss, schedule disruption and potential safety concerns. Less severe telemetry disruptions can also result in missing or garbled telemetry data, negatively impacting platform test, analysis and design modification cycles. This paper provides a high level overview of a physics-compliant Range Test System (RTS) built upon Radio Frequency (RF) Channel Simulator technology. The system is useful in verifying range operation with most range equipment configured to function as in an actual mission. The system generates RF signals with appropriate RF link effects associated with range and range rate between the flight platform and multiple telemetry tracking stations. It also emulates flight and RF characteristics of the platform, to include signal parameters, antenna modeling, body shielding and accurate flight parameters. The system is useful for hardware, software, firmware and process testing, regression testing, and fault detection test, as well as range customer assurance, and range personnel training against nominal and worst-case conditions.
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Studies of signal and noise properties of perpendicular recording mediaChooruang, Komkrit January 2010 (has links)
Areal densities of perpendicular hard-disk drives over 500Gb/in2 have already been demonstrated, with 1Tb/in2 densities being forecasted in the near future. However, at these high areal densities the information bearing units on the magnetic storage medium are magnetically unstable at temperatures expected in hard-disk drives. To extend or bypass this limit, new developments in head and media technologies and understanding of their record, readout and noise performances are necessary. The aim of this project was to study the record, readout and noise properties of conventional and future perpendicular magnetic recording media, heads and their related technologies. The objectives were therefore to develop a flexible and robust experimental recording platform to test the performance of different heads and media, and develop the necessary readout theory to predict the replay performance. In line with the project objectives, a high-precision open contact recording tester was developed with 1nm resolution. The open nature of this system allows different heads and media combinations to be tested. A second, closed system was also developed based on a commercial perpendicular hard-drive, modified to serve as a spin-stand to provide signal and noise measurements in practical drive conditions. The readout process in perpendicular recording was modelled based on the reciprocity principle for a shielded TMR head to study the parameters that affect the readout signal performance, and for comparison with the experimental measurements. Measured signal roll-off curves showed a practical linear density of 450KFCI for the commercial perpendicular disk medium, and indicated that non-linear effects happen at linear densities approaching 550KFCI. These results were in agreement with the theoretical calculations of the replay process. Two-dimensional readout scans were found have similar or higher resolution than Magnetic Force Microscopy (MFM) images of the same recorded regions – indicating the versatility and precision of the developed contact tester. Inverse filtering employing the Wiener filter was used to extract the magnetic transition. The extracted transition profiles and transition extents from the replay signals had much higher resolution than MFM images measured for the same transition region, thus showing the applicability of the developed testers for in situ magnetic characterisation. The developed contact and non-contact testers allowed the investigation of a new proposed recording scheme, Shingled Magnetic Recording (SMR). Measured signal roll-off curves of shingled tracks indicated a rise in the signal amplitude at low densities. At higher linear densities the signal performance was the same as conventionally written tracks with guardbands. It was found that a 30% reduction in track width in SMR, increase the areal density by a factor of 1.58 above that in existing hard drives.
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The Effect of the Note-test System of Teaching Basic College Chemistry on Student Achievement, Attitude, and Critical Thinking AbilityCollier, Donald Davis 12 1900 (has links)
The problem of this study was to determine the relative effectiveness of the note-test system and the traditional lecture system of teaching basic college chemistry.
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Drug Testing: Technology, Tricks and the Two-Test SystemBrown, Stacy D. 01 September 2013 (has links)
No description available.
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Syntetiska InstrumentBorg, Daniel, Mantling, Ulf January 2009 (has links)
<p>This thesis aims to investigate SAAB AB´s possibilities to use synthetic instruments in their test systems. The reason for this is reducing costs and the risk of obsolescence which is common when test systems operate for several decades.</p><p>The market around synthetic instruments has been explored in the search for suitable hardware and software. Software has been developed in LabVIEW and synthetic instruments have been created with the help of IVI-drivers. The hardware consisted of PXI-instruments (Waveform generator and Digitizer), connected to a computer using a fiber optic link and PXI-chassi. The created instruments was then compared to common instruments used today, and the comparison turned out well. Advantages, disadvantages and the theory surrounding synthetic instruments is also covered. This thesis is only an introduction and further work will be necessary to implement synthetic instruments at SAAB.</p><p>The thesis also purposes suitable hardware and further development based on the test systems used today, and how it is possible to solve the layer structure.</p> / <p>Detta examensarbete har som mål att undersöka möjligheterna för SAAB AB att börja använda sig av syntetiska mätinstrument i sina testsystem. Anledningen till detta är att SAAB AB vill minska kostnaderna och riskerna för obsolescens som finns när testsystem är i drift i flera decennier. Detta har inneburit att marknaden har sonderats efter lämplig hårdvara och mjukvara för tillämpningen. Förutom detta har mjukvara tagits fram i LabVIEW och syntetiska instrument skapats med hjälp av IVI-drivrutiner. Som hårdvara användes PXI-instrument (vågformsgenerator och digitizer) med tillhörande chassi och fiberoptisk länk från National Instruments. De framtagna instrumenten har jämförts med vanliga reella instrument och visat sig fungera väl, men även fördelar och nackdelar belyses samt teori kring hur syntetiska instrument fungerar. Examensarbetet är endast en introduktion i ämnet och kräver ytterligare arbete innan det är praktiskt genomförbart. Förutom detta ges även förslag på lämplig hårdvara och vidareutveckling baserat på hur testsystemen ser ut i dag, och förslag på hur lageruppbyggnaden skulle kunna lösas.</p>
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