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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.
181

Exploiting DNA Repair Vulnerabilities to Modulate Anti-Cancer Immunity : a Study of the Immunological Potential of PARP inhibitors / Exploiter les défauts de réparation de l’ADN pour moduler l’immunité anti-cancéreuse : une étude du potentiel immunologique des inhibiteurs de PARP

Chabanon, Roman 31 January 2019 (has links)
Les inhibiteurs de poly(ADP-ribose) polymérase (PARPi) ciblent sélectivement les cellules porteuses de défauts des voies de réparation de l’ADN tels que les mutations de BRCA1/2 et les défauts d’ERCC1. Sur le plan clinique, plusieurs PARPi ont été approuvés pour le traitement des cancers BRCA-mutés ou platine-sensibles du sein et de l’ovaire, et des essais cliniques sont en cours pour évaluer l’efficacité des PARPi dans le cancer bronchique non-à-petites cellules (CBNPC) platine-sensible. Alors que les PARPi ont un fort potentiel thérapeutique dans les cancers comportant des défauts de réparation de l’ADN, de plus en plus d’essais cliniques évaluent également l’efficacité de ces médicaments en combinaison avec les « inhibiteurs d’immune checkpoints » (ICI) dans diverses populations de patients. Dans ce contexte, il est essentiel de mieux comprendre comment les PARPi modulent la réponse immunitaire anti-tumorale, et d’étudier le potentiel immunologique inhérent de ces médicaments.Dans cette étude, nous avons établi que les cellules de CBNPC déficientes en ERCC1 expriment fortement la signature interféron (IFN) de type I, et que les tumeurs de CBNPC ayant une faible expression d’ERCC1 ont un infiltrat lymphocytaire renforcé. En utilisant des lignées cellulaires isogéniques et des xénogreffes dérivées de patients, nous avons montré que plusieurs PARPi, notamment l’olaparib et le rucaparib, ont des propriétés immunomodulatrices dans les modèles de CBNPC ERCC1-déficients et de cancers du sein triple-négatifs (CSTN) BRCA1-mutés. D’un point de vue mécanistique, les PARPi génèrent des fragments d’ADN cytoplasmiques ayant les caractéristiques de micronoyaux ; ceux-ci activent la voie cGAS/STING et déclenchent une réponse IFN de type I, associée à la sécrétion de la cytokine CCL5. De manière importante, ces effets sont largement diminués dans les cellules de CSTN BRCA1-révertantes et les cellules de CBNPC ré-exprimant ERCC1, ce qui suggère que les défauts de réparation de l’ADN amplifient les phénotypes immunitaires associés au traitement par PARPi. En outre, ces effets sont totalement abrogés dans les cellules de CSTN PARP1-neutralisées, ce qui confirme que les phénotypes observés dépendent d’un effet spécifique des PARPi sur leur cible.Au-delà de leur potentiel d’activation d’une immunité spécifique des cellules cancéreuses via cGAS/STING et la signalisation IFN de type I, nous avons également constaté que les PARPi potentialisent les effets inducteurs de l‘IFN de type II sur l’expression de PD-L1 dans des lignées cellulaires et cellules tumorales fraîches de patients CBNPC, surtout en présence de défauts d’ERCC1. De plus, nous avons montré que certains PARPi, utilisés à des concentrations létales, activent de manière indépendante les éléments moléculaires clés de la mort cellulaire immunogénique, dont l’exposition de la calréticuline à la surface des cellules cancéreuses, la sécrétion d’ATP et le relargage d’HMGB1 en grandes quantités dans le milieu extracellulaire.Dans l’ensemble, ces données précliniques suggèrent que les PARPi ont des propriétés immunomodulatrices intrinsèques qui participent à l’activation de réponses immunitaires anti-tumorales ; ce potentiel pourrait être exploité cliniquement en combinaison avec les ICI dans des populations adéquatement sélectionnées au plan moléculaire. / Poly(ADP-ribose) polymerase inhibitors (PARPi) selectively target cancer cells with DNA repair deficiencies such as BRCA1/2 mutations or ERCC1 defects. Clinically, several PARPi are currently approved for the treatment of BRCA-mutant or platinum-sensitive advanced ovarian and breast cancers, and ongoing clinical trials are investigating the efficacy of PARPi in platinum-sensitive Non-Small Cell Lung Cancer (NSCLC). While PARPi constitute potent targeted therapies for the treatment of DNA repair-deficient malignancies, an increasing number of clinical trials are also evaluating their efficacy in combination with immune checkpoint inhibitor (ICI) in various populations. In this context, it is of critical importance to better understand how PARPi might modulate immune responses against cancer, and to investigate the inherent immunological potential of these agents.In this study, we show that ERCC1-defective NSCLC cells exhibit an enhanced type I interferon (IFN) transcriptomic signature and that low ERCC1 expression correlates with increased lymphocytic infiltration in human NSCLC tumours. Using isogenic cell lines and patient-derived xenografts, we further demonstrate that several clinical PARPi, including olaparib and rucaparib, display cell-autonomous immunomodulatory properties in ERCC1-defective NSCLC and BRCA1-mutant triple-negative breast cancer (TNBC) models. Mechanistically, PARPi generate cytoplasmic chromatin fragments with micronuclei characteristics; this activates the cGAS/STING pathway and elicits downstream type I IFN signalling and CCL5 secretion. Importantly, these effects are suppressed in BRCA1-reverted TNBC cells and ERCC1-rescued NSCLC cells, suggesting that DNA repair defects exacerbate the innate immunity-related phenotypes triggered by PARPi. Similarly, these effects are totally abrogated in PARP1-null TNBC cells, supporting the on-target effect of PARPi in mediating such phenotypes. Besides this potential to activate tumour cell-autonomous immunity through cGAS/STING and type I IFN signalling, we also observed that PARPi synergize with type II IFN to induce PD-L1 expression in NSCLC cell lines and fresh patient tumour cells, especially in the ERCC1-deficient setting. Moreover, we show that lethal concentrations of some PARPi independently activate the key damage-associated molecular patterns dictating the immunogenicity of cancer cell death, including calreticulin exposure at the tumour cell surface, ATP secretion and HMGB1 release in the extracellular compartment.Together, these preclinical data suggest that PARPi have intrinsic immunomodulatory properties that activate anti-cancer immune responses; this could be exploited clinically in combination with ICI in appropriately molecularly-selected populations.
182

Examensarbete i industriell teknik vid Scania R&D / Degree project in industrial technology and management at Scania R&D

Löfholm, Birgitta January 2020 (has links)
The study aims to study if it is possible to reduce lead time or resource needs by studying the PD process, Product Development Process linked to the improvement area Unclear requirements from managers on measuring the process. This is done by studying current control, the possibility of using other measuring points and how a measurement system could be established, including Scorecard within Scania R&D, Research and Development. The study is based on the questions What does the product development process look like? What could be measured in the product development process? and How could a measurement system with integrated Scorecard be implemented for better control of the product development process? Theories include the areas of processes, process control, process measurement and process management. Interviews, group interviews, document studies, literature studies and previous research were the basis for studying the problem and opportunities for improvement. All data collection was done remotely as Covid-19 had major impacts. The result of the study shows that R&D does not currently measure the PD process, but measurement is regulated in internal documents. Measurement of lead time, resources and costs was desired by interviewees to measure. Basing the measurement on the current KPI, Key Performance Indicators, and R&D strategic plan 2020 implies established support from the functions that produced the internal documents. The developed measurement system includes the measurement points lead time, cost and resource requirements as well as selected milestones. An introduction of the measurement system would, for Scania R&D, provide an opportunity to control the PD process linked to the measurement points. The measurement system has largely been based on internal documents to increase the relevance of the measurement system and the possibility of an introduction. / Studien syftar till att studera om det går att minska ledtid eller resursbehov genom att studera PD processen, Product Development Process, kopplat till förbättringsområdet Otydliga krav från chefer på mätning av processen. Det utförs genom att studera nuvarande styrning, möjligheten att använda andra mätpunkter samt hur ett mätsystem skulle kunna upprättas inkluderat Scorecard inom Scania R&D, Research and Development. Studien baserar sig på frågeställningarna Hur ser produktframtagningsprocessen ut? Vad skulle kunna mätas i produktframtagningsprocessen? samt Hur skulle ett mätsystem med integrerat Scorecard kunna implementeras för bättre styrning av produktframtagningsprocessen? Teorier berör områdena processer, processtyrning, processmätning och processledning. Intervjuer, gruppintervju, dokumentstudier, litteraturstudier och tidigare forskning låg till grund för att studera problemet och förbättringsmöjligheter. Samtlig datainsamling utfördes på distans då Covid-19 hade stora påverkningar. Studiens resultat visar att R&D i nuläget inte mäter PD processen men mätning finns reglerat i interna dokument. Mätning av ledtid, resurser och kostnader var önskat av intervjupersoner att mäta. Att basera mätningen på nuvarande KPI, Key Performance Indicators, och R&D strategisk plan 2020 innebär ett etablerat stöd hos de funktioner som tagit fram de interna dokumenten. Det framtagna mätsystemet inkluderar mätpunkterna ledtid, kostnad och resursbehov samt utvalda milstolpar. Ett införande av mätsystemet skulle för Scania R&D innebära en möjlighet till att styra PD processen kopplat till mätpunkterna. Mätsystemet har till stor del baserats på interna dokument för att öka mätsystemets relevans samt möjligheten till ett införande.
183

Contribution à l'étude de la dépollution de l'air chargé en composés organiques volatils par un procédé associant un plasma de décharge à barrière diélectrique impulsionnelle et des catalyseurs / Removal of volatile organic compounds using pulsed dielectric barrier discharge plasma combined to catalysts

Pham, Huu Thien 29 September 2014 (has links)
Cette thèse s’inscrit dans le cadre général de la dépollution d’effluents gazeux faiblement chargés en Composés Organiques Volatils (COV). L’étude concerne l'oxydation de trois COV cibles (méthane, propène, et toluène) dans l'air à la pression atmosphérique dans d'une part un réacteur plasma de décharge à barrière diélectrique (DBD) pulsée et un réacteur catalytique utilisés séparément et d'autre part, dans un réacteur hybride associant le réacteur plasma aux catalyseurs dans deux configurations: le catalyseur au coeur de la décharge et le catalyseur en post-décharge. Les catalyseurs sont à base de Pd, Mn, Cu, et Co supportés sur des billes de Al2O3. Ils ont été caractérisés par ICP-OES, TEM/EDX, XRD, XPS, et DRIFTS. L’efficacité de conversion des COV, la sélectivité en CO/CO2, ainsi que la nature et les concentrations des produits formés pour les trois molécules avec les trois systèmes ont été étudiées en fonction de la température du gaz, de l'énergie injectée, de la concentration des COV, de la taille du support, du type de métal et sa teneur, et de la vitesse volumique horaire. Dans tous les cas, l’activation des catalyseurs à basse température a été démontrée quand ces derniers sont couplés au plasma et les principaux produits de réaction identifiés et quantifiés par spectroscopie infrarouge à transformée de Fourier. Le couplage plasma-catalyseur améliore de façon significative l’efficacité de conversion du méthane, du propène, et du toluène dans l’air ainsi que la sélectivité en sous-produits. L'effet de synergie entre le plasma et les catalyseurs pour la conversion des COV a été démontré dès lors que le plasma est généré directement au sein du réacteur catalytique. / The focus of this thesis is the application of non-thermal plasma and catalysis in chemical processing, in particular for the removal of Volatile Organic Compounds (VOC) diluted in air. In a first part, the oxidation of three pollutants (methane, propene, and toluene) is studied experimentally in a pulsed dielectric barrier discharge (DBD) reactor and in a catalyst reactor working independently. In a second part, a hybrid plasma-catalyst reactor either in a single-stage or in a two-stages configuration, in which the catalyst is located inside or downstream from the plasma reactor, respectively. Catalyst materials based on Pd, Mn, Cu, and Co supported on alumina beads were tested and characterized by ICP-OES, TEM/EDX, XRD, XPS, and DRIFTS. Products were analyzed and quantified by infrared spectroscopy. Achieved VOCs removal efficiencies and CO/CO2 selectivity, as well as nature and concentrations of the formed products, were evaluated as function of many factors, particularly the specific input energy, the gas temperature, the initial VOCs concentration, the nature of catalyst (size support, metal loading), and the hourly space velocity. It has been successfully demonstrated that the combination of plasma and catalyst in the both configurations has many benefits compared to traditional thermal-catalysis and plasma alone treatment including a lowering of the catalyst operating temperature, an improvement of the conversion of VOCs at similar temperatures, and a better end-products selectivity and energy efficiency. The mutual interaction lead to a synergistic effect in plasma-catalysis especially when the discharge is in direct contact with the catalyst whatever the VOCs studied.
184

Strukturell komplexe intermetallische Phasen : Untersuchungen an binären und ternären Phasen der Systeme Ag-Mg und Ag-Ga-Mg

Kudla, Christian 16 November 2007 (has links)
Im Rahmen der Dissertation wurden Komplexe Intermetallische Phasen (KIP) in den Systemen Ag-Mg und Ag-Ga-Mg dargestellt und charakterisiert. KIP sind Verbindungen, die sich grundlegend von einfachen Metallen unterscheiden. Große Elementarzellen, ein hierarchisch strukturierter Aufbau und inhärente Fehlordnung sind wesentliche Charakteristika. Empirisch wird zudem eine Häufung von strukturchemisch verwandten KIP (Ähnlichkeitsregel) in der Nähe von definierten Zusammensetzungen beobachtet (Häufungsregel). Obwohl nur wenig über die physikalischen Eigenschaften dieser Verbindungsklasse bekannt ist, zeigen neueste Untersuchungen, dass sie interessante Eigenschaften wie ungewöhnliches plastisches Verhalten und Pseudo-Bandlücken in der elektronischen Zustandsdichte in Höhe der Fermi-Energie aufweisen können. Diese Arbeit zeigt exemplarisch, dass in der Chemie der KIP durchaus einfache Regeln (Häufungs-, Ähnlichkeits-, Valenzelektronenkonzentrationsregel) genutzt werden können, um neue Verbindungen mit vorgegebenen geometrischen Baueinheiten aufzufinden. Vereinfachende Annahmen, wie die Aussage, dass zweikomponentige Mackay-Cluster keine Fehlordnung aufweisen oder dass ein Mackay-Cluster maximal 92 Valenzelektronen enthält, erwiesen sich hingegen als falsch. Die Untersuchungen haben gezeigt, dass eine Kombination verschiedener Synthesemethoden notwendig ist. Insbesondere hat sich das Schmelzspinnverfahren, das zur Darstellung kristalliner magnesiumreicher Legierungen angewandt und modifiziert wurde, bei der phasenreinen Synthese der Verbindungen bewährt. Die Entwicklung von Spritzdüsen aus Tantal ermöglichte die kontaminationsfreie Verarbeitung der Mg-haltigen Legierungen. Die Bestimmung der Kristallstrukturen inklusive der Fehlordnungsphänomene war für das Verständnis der Stabilität der KIP entscheidend. Da häufig zwischen verschiedenen Modellen zur Beschreibung der Fehlordnung entschieden werden musste, waren neben präzisen Beugungsdaten genaue Untersuchungen der Präparate mittels chemischer Analytik, Metallographie und WDX hinsichtlich der Zusammensetzung aller Phasen erforderlich. Der magnesiumreiche Teil des binären Phasendiagramms Ag-Mg wurde neu bestimmt. Dabei wurden zwei bislang unbekannte Phasen dargestellt. Die fünf magnesiumreichen Phasen kristallisieren innerhalb eines schmalen Bereichs von nur 9 At.-% Mg. Die Kristallstrukturen dieser Phasen wurden unter besonderer Berücksichtigung der Fehlordnungsphänomene untersucht. Die Verbindungen sind strukturchemisch verwandt und lassen sich den I3-Cluster-Phasen zuordnen. Ag2Mg5 kristallisiert ohne Fehlordnung im Al5Co2-Typ. Die Kristallstrukturen von Ag7Mg26 und Ag17Mg54 lassen sich als fcc bzw. bcc Anordnungen von Mackay-Clustern beschreiben. Es handelt sich um die ersten bekannten binären Phasen, in denen innerhalb von isolierten Mackay-Clustern Substitutionsfehlordnung auftritt. AgMg4 kristallisiert hexagonal in einem eigenen Strukturtyp. Das I3-Cluster-Netzwerk füllt den gesamten Raum bis auf einen annähernd zylindrischen Bereich um 0, 0, z, in dem eine Atom-Split-Position aus drei Lagen vorliegt. Lokal liegen drei unterschiedliche Koordinationspolyeder vor, deren Stapelabfolge in der Kristallstruktur von AgMg4 zufällig ist, jedoch mit kurzreichweitiger Korrelation. Es konnte gezeigt werden, dass sich AgMg4 in eine Tieftemperaturphase umwandelt, in der die Polyeder vermutlich langreichweitig unter Bildung einer Überstruktur ordnen. Der Phasenbestand des ternären Systems Ag-Ga-Mg wurde untersucht und die Kristallstrukturen von sechs neuen Phasen bestimmt. Des weitern wurde eine Verbindung im System Ga-Mg-Pd charakterisiert. Anhand der Strukturtypen Al3Ir und Cu3P sowie den Verbindungen Ag0,55Ga0,45Mg3, Ga4,62Mg13,38Pd7 und Ag1,31Ga1,89Mg7,80 wurde gezeigt, wie die Variation von Strukturmotiven durch geringe Abweichungen von idealer Symmetrie zu zunehmend komplexeren Kristallstrukturen führt, die sich stets von Packungen des Edshammarpolyeders ableiten lassen. Drei ternäre Phasen vom I3-Cluster-Typ konnten identifiziert werden: Neben ternären Varianten der Phasen Ag7Mg26 und Ag17Mg54 kristallisiert Ag0,59Ga0,41Mg2 metastabil im NiTi2-Typ. In den strukturchemisch verwandten Phasen Ag6Ga12Mg11 und Ag21Ga74Mg44 bilden die Mg Atome Netzwerke mit Clatrath-II- bzw. Clatrath-IV-Topologie, die mit Ikosaedern und Frank-Kasper-Polyedern aus Ag und Ga gefüllt sind. Diese Phasen werden wahrscheinlich durch das e/a-Verhältnis der gesamten Struktur im Sinne einer Hume-Rothery-Regel stabilisiert.
185

Translation of pharmacometric models from NONMEM to nlmixr2 and RxODE2

Borg, Johan January 2023 (has links)
The gold standard for pharmacometrics modeling, along with its modeling format, is currently NONMEM. In order to use other software, there is often a manual step of converting a model from one format to another, which is both time-consuming and causes manual errors. This project aimed to solve this problem by creating a conversion- and validation tool from NONMEM to two formats: nlmixr2 and RxODE2. These are both, unlike NONMEM, freely available and integrated into R. This was done by integrating the two tools (conversion and validation) into the program Pharmpy, which can extract model information from NONMEM's model format. For conversion, the model was read into Pharmpy and then, part by part, converted to the respective model format. The associated validation compared the predictions of the respective programs to see if they differed significantly from each other. The project showed that this type of conversion is possible, but the programs showed a greater difference than expected. Part of this can be explained by a rounding of parameter values in Pharmpy, but further analysis also indicated fundamental differences in the determination of the predictions between the programs. Larger differences in predictions are for instance oftentimes equidistant from the actual observation, meaning the predictions are presumably calculated differently. While not disproving the converted model, smaller discrepancies between the programs would indicate a more confident validation. In summary, the developed tools are considered useful for models where Pharmpy supports parsing of the model. If not for complete conversion, then at least for partial conversion with manual correction, which is also an improvement over an entirely manual workflow.
186

Utvärdering av biomarkörerna PD-L1 och calretinin i parade histologiska och cytologiska provmaterial från patienter med mesoteliom / Evaluation of the biomarkers PD-L1 and calretinin in paired histological and cytological specimen from patients with mesothelioma

Andersson, Anni January 2023 (has links)
Malignt mesoteliom är en ovanlig och aggressiv cancerform. Den är vanligast i pleura och kallas då pleuralt mesoteliom. Vanligaste orsaken till utveckling av pleuralt mesoteliom är exponering för asbest. Insjuknande patienter har dålig prognos och begränsade behandlingsmöjligheter. Röntgen kan i ett första stadie ge diagnos av sjukdomen. Oftast behövs också en biopsi tas för fastställande av diagnos. Även provtagning av pleuravätskan kan ge värdefull diagnostisk information. Immunhistokemi är en viktig tilläggsanalys för diagnos med biopsier och cellblock. Immunhistokemi innebär färgning med antikroppar. För pleuralt mesoteliom kan exempelvis antikropparna PD-L1 och calretinin användas för diagnostisering. I denna studie färgades 10 parade pleurabiopsier och cellblock från pleuravätska från patienter med malignt mesoteliom. Antikropparna PD-L1 och calretinin användes. Syftet var att utvärdera uttrycket av PD-L1 och calretinin. Alla infärgade glas undersöktes i ljusmikroskop. För PD-L1 ansågs enbart membranfärgning som positivt infärgad och för calretinin ansågs cytoplasmatisk och/eller kärnfärgning som positiv. Procentuellt antal positiva tumörceller undersöktes vid två cutoff värden, ≥1 % och ≥10 %. Procentuellt antal <1 % vid cutoff ≥1 % och procentuellt antal <10 % vid cutoff ≥10 % ansågs negativt. Detta gällde för båda antikropparna. Antal positiva och negativa biopsier samt cellblock och konkordansen redovisades. Overall percentage agreement (OPA), Cohen’s kappa (κ) och konfidensintervall (CI) beräknades också. Resultatet visade på lägre antal positiva färgningar för cellblocken jämfört med biopsierna för båda antikropparna. För konkordansen visades att den vara lika för PD-L1 och calretinin vid cutoff ≥1 % men högre för PD-L1 än för calretinin vid cutoff ≥10 %. / Malignant mesothelioma is a rare and aggressive cancer. It is most common in the pleura, called pleural mesothelioma. The most common reason for developing pleural mesothelioma is exposure to asbestosis. Patients that get sick have a poor prognosis and limited treatment options. X-ray can in a first stadium give diagnose of the disease. A biopsy is often necessary to confirm the diagnosis. Even sampling of pleural fluid can give valuable diagnostic information. Immunohistochemistry is a common additional analysis for diagnosis with biopsy and cell block. Immunohistochemistry implies staining with antibodies. For example, for pleural mesothelioma the antibodies PD-L1 and calretinin can be used for diagnosis. In this study 10 paired pleural biopsies and cell blocks from pleural fluid from patients with malign mesothelioma were immunostained. The study aimed to evaluate expression of PD-L1 and calretinin. All the stained glasses were evaluated by a light microscope. For PD-L1, only membranous staining was considered positive and for calretinin cytoplasmic and/or nuclear staining was considered positive. Percentage number of positive tumor cells were evaluated at two cutoff values, ≥1 % and ≥10 %. Percentage number <1 % at cutoff ≥1 % and percentage number <10 % at cutoff ≥10 % were considered negative. The same criteria were applied for both antibodies. The number of positive and negative biopsies as well as cell blocks and the concordance were reported. Overall percentage agreement (OPA), Cohen’s kappa (κ) and confidence interval (CI) was also calculated. Result showed lower number of positive staining for the cell blocks than for the biopsies for both antibodies. The concordance was shown to be equal for PD-L1 and calretinin at cutoff ≥1 % but higher for PD-L1 than for calretinin at cutoff ≥10 %.
187

Immunomodulatory Effects by Photodynamic Treatment of Glioblastoma Cells In Vitro

Rothe, Friederike, Patties, Ina, Kortmann, Rolf-Dieter, Glasow, Annegret 08 September 2023 (has links)
Multimodal treatment adding immunotherapy and photodynamic treatment (PDT) to standard therapy might improve the devastating therapeutic outcome of glioblastoma multiforme patients. As a first step, we provide investigations to optimize dendritic cell (DC) vaccination by using PDT and ionizing radiation (IR) to achieve maximal synergistic effects. In vitro experiments were conducted on murine glioblastoma GL261 cells, primary DCs differentiated from bone marrow and T cells, isolated from the spleen. Induction of cell death, reactive oxygen species, and inhibition of proliferation by tetrahydroporphyrin-tetratosylat (THPTS)-PDT and IR were confirmed by WST-1, LDH, ROS, and BrdU assay. Tumor cargo (lysate or cells) for DC load was treated with different combinations of THPTS-PDT, freeze/thaw cycles, and IR and immunogenicity analyzed by induction of T-cell activation. Cellular markers (CD11c, 83, 86, 40, 44, 69, 3, 4, 8, PD-L1) were quantified by flow cytometry. Cytotoxic T-cell response was evaluated by calcein AM assay. Immunogenicity of THPTS-PDT-treated GL261 cells lysate was superior to IR-treated lysate, or treated whole cells proven by increased DC phagocytosis, T-cell adhesion, proliferation, cytolytic activity, and cytokine release. These data strongly support the application of PDT together with IR for optimal immunogenic cell death induction in tumor cell lysate used to pulse DC vaccines.
188

Non-intrusive condition monitoring of power cables within the industrial sector / Johannes Hendrik van Jaarsveldt

Van Jaarsveldt, Johannes Hendrik January 2015 (has links)
Condition monitoring (CM) of electrical equipment is an important field in electrical engineering and a considerable amount of research is dedicated to this field. Power cables are one of the most important parts of any electrical network and the variety of techniques available for CM of electrical cables is therefore no surprise. Electrical cables are exposed to operational and environmental stressors which will cause degradation of the insulation material. The degradation will continue to the point where the cable fails. Blackouts caused by failing cables will have an effect on the safety, efficiency and production of an electrical network. It is therefore important to constantly monitor the condition of electrical cables, in order to prevent the premature failure of cables. The research presented in this dissertation sets out to investigate CM techniques for power cables and to design and implement a basic cable CM technique based on the principles of partial discharge (PD) measurements. A comprehensive literature study introduces the fundamental concepts regarding the CM of power cables. The basic construction of electrical cables, as well as the variety of different types is researched in order to lay a foundation for the research that follow. CM techniques for electrical equipment are investigated, with the emphasis on techniques used on cables. Conducted research led to the decision to focus on CM by means of PD measurements. PD as a phenomenon is investigated to be able to better understand the origins and effects of discharge activity. From there the focus shifts to the available techniques for monitoring the condition of electrical cables by means of PD measurements. The research conducted in the literature study chapter forms the basis from which the rest of the study is conducted. Simulation models were used to study PD characteristics. The models are derived from engineering and mathematical principles and are based on the well-known three-capacitor model of PD. The simulations were performed in order to study the effects of discharge activity. The designed simulation models allows for a variety of PD characteristics to be studied. The simulations were performed in the MATLAB® Simulink® environment. The research conducted in the dissertation was used to design an elementary CM technique which can be used to detect the presence of PD within electrical cables. The designed CM technique was used for the practical measurement of PD data. MATLAB® programs were designed in order to analyse the PD data in both the time- and frequency-domain. The analysis of the measured data revealed PD characteristics of the test specimen used for the measurements. The designed CM is used for the detection of PD activity within electrical cables and in combination with other techniques, may be used for complete CM of electrical cables. The experimental setup which was used to take practical PD measurements adds another dimension to the work presented in this dissertation. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
189

Non-intrusive condition monitoring of power cables within the industrial sector / Johannes Hendrik van Jaarsveldt

Van Jaarsveldt, Johannes Hendrik January 2015 (has links)
Condition monitoring (CM) of electrical equipment is an important field in electrical engineering and a considerable amount of research is dedicated to this field. Power cables are one of the most important parts of any electrical network and the variety of techniques available for CM of electrical cables is therefore no surprise. Electrical cables are exposed to operational and environmental stressors which will cause degradation of the insulation material. The degradation will continue to the point where the cable fails. Blackouts caused by failing cables will have an effect on the safety, efficiency and production of an electrical network. It is therefore important to constantly monitor the condition of electrical cables, in order to prevent the premature failure of cables. The research presented in this dissertation sets out to investigate CM techniques for power cables and to design and implement a basic cable CM technique based on the principles of partial discharge (PD) measurements. A comprehensive literature study introduces the fundamental concepts regarding the CM of power cables. The basic construction of electrical cables, as well as the variety of different types is researched in order to lay a foundation for the research that follow. CM techniques for electrical equipment are investigated, with the emphasis on techniques used on cables. Conducted research led to the decision to focus on CM by means of PD measurements. PD as a phenomenon is investigated to be able to better understand the origins and effects of discharge activity. From there the focus shifts to the available techniques for monitoring the condition of electrical cables by means of PD measurements. The research conducted in the literature study chapter forms the basis from which the rest of the study is conducted. Simulation models were used to study PD characteristics. The models are derived from engineering and mathematical principles and are based on the well-known three-capacitor model of PD. The simulations were performed in order to study the effects of discharge activity. The designed simulation models allows for a variety of PD characteristics to be studied. The simulations were performed in the MATLAB® Simulink® environment. The research conducted in the dissertation was used to design an elementary CM technique which can be used to detect the presence of PD within electrical cables. The designed CM technique was used for the practical measurement of PD data. MATLAB® programs were designed in order to analyse the PD data in both the time- and frequency-domain. The analysis of the measured data revealed PD characteristics of the test specimen used for the measurements. The designed CM is used for the detection of PD activity within electrical cables and in combination with other techniques, may be used for complete CM of electrical cables. The experimental setup which was used to take practical PD measurements adds another dimension to the work presented in this dissertation. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
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Physiologically Based Pharmacometric Models for Colistin and the Immune Response to Bacterial Infection

Bouchene, Salim January 2016 (has links)
Antibiotic treatment failure might be due to bacterial resistance or suboptimal exposure at target site and there is a lack of knowledge on the interaction between antimicrobial pharmacodynamics (PD) and the immune response to bacterial infections. Therefore, it is crucial to develop tools to increase the understanding of drug disposition to better evaluate antibiotic candidates in drug development and to elucidate the role of the immune system in bacterial infections. Colistin is used as salvage therapy against multidrug resistant Gram-negative infections. In this work, a whole-body physiologically based pharmacokinetic model (WBPBPK) was developed to characterize the pharmacokinetics (PK) of colistin and its prodrug colistin methanesulfonate (CMS) in animal and human. The scalability of the model from animal to human was assessed with satisfactory predictive performance for CMS and demonstrating the need for a mechanistic understanding of colistin elimination. The WBPBPK model was applied to investigate the impact of pathophysiological changes commonly observed in critically ill patients on tissue distribution of colistin and to evaluate different dosing strategies. Model predicted concentrations in tissue were used in combination with a semi-mechanistic PKPD model to predict bacterial killing in tissue for two strains of Pseudomonas aeruginosa. Finally, a toxicokinetic (TK) model was constructed to describe the time course of E. coli endotoxin concentrations in plasma and the effect on pro-inflammatory cytokine release. The model adequately described the concentration-time profiles of endotoxin and its stimulation of IL-6 and TNF-α production using an indirect response model combined with a transit compartment chain with a tolerance component to endotoxemia. The WBPBPK model developed in this work increased the knowledge on colistin tissue exposure under various conditions and could be used in drug development process to assess antibiotic efficacy or to test new drug combinations. The model describing endotoxin TK and its effect on cytokines is a new tool to be further applied in longitudinal studies to explore the immune response cascade induced by bacterial infections. The methodology applied in this thesis contributes to the development of an integrated modeling framework including physiology, drug distribution, bacterial growth and killing as well as the immune response to infection.

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