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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.
31

Pat Metheny Plays the Blues

Kunovic, Anthony 30 May 2017 (has links)
No description available.
32

Acquisition time in laser inter-satellite link under satellite vibrations

Lee, K., Mai, Vuong, Kim, H. 11 August 2024 (has links)
Yes / Pointing, acquisition, and tracking (PAT) is a major technical challenge of laser inter-satellite links (ISLs). For the fast establishment of laser link and the maximization of communication time, it is of importance to minimize the acquisition time. Satellite vibrations affect the PAT procedure adversely, and thus serve to increase the acquisition time. In this paper, we investigate through theoretical analysis the average acquisition time of laser ISLs in the presence of satellite vibrations. The analytic expression about the time taken from the beginning of spiral scan to the acquisition of the scan beam is provided in the presence of the pointing errors caused by vibrations. We also derive the optimum beam divergence angle for the acquisition time. The analyses are validated by Monte-Carlo computer simulations and a proof-of-concept experiment. The results show that the acquisition time can be minimized by adjusting the beam divergence angle adaptively to the link conditions. / Grant-in-aid of Hanwha Systems
33

Sambandet mellanägaridentitet ochhållbarhetsrevision / The relationship between ownership identity and sustainability reportingassurance

Bellis, Linnea, Jishammar, Karolina January 2018 (has links)
Bakgrund Från och med räkenskapsår som påbörjas efter den 31 december 2016 är det obligatoriskt för stora svenska aktiebolag att upprätta en hållbarhetsrapport. Lagstiftaren har dock inte krävt att hållbarhetsrapporten ska granskas av en revisor. Både publika och kommunala bolag omfattas av den nya lagstiftningen. Utifrån positiv redovisningsteori (PAT) och institutionell teori (IT) kan det tänkas att bolagens olika ägaridentiteter påverkar deras behov av hållbarhetsrevision. Syfte Syftet med studien är att förklara sambandet mellan ägaridentitet och hållbarhetsrevision i svenska aktiebolag. Vidare ska vi analysera vilka faktorer som påverkar kommunala aktiebolags beslut att antingen välja eller avstå från hållbarhetsrevision. Metod Denna kvantitativa studie har ett deduktivt angreppssätt. Utifrån PAT och IT har tre hypoteser formulerats. En tvärsnittsdesign har använts och sekundärdata i form av årsredovisningar från företagens hemsidor har analyserats med logistisk regression. Dessutom har en kompletterande analys i form av fyra semistrukturerade intervjuer genomförts med representanter från kommunala aktiebolag. Slutsats Ägaridentitet var inte statistiskt signifikant, men resultatet bör beaktas med viss försiktighet, eftersom endast tre kommunala bolag valde hållbarhetsrevision. Resultaten från de semistrukturerade intervjuerna visar visst stöd för både PAT och IT. Slutligen visar studiens resultat ett signifikant samband mellan hållbarhetsrevision och kontrollvariablerna storlek och bransch. / Introduction Since the 31th of December 2016, sustainability reporting has been mandatory for big companies in Sweden. The legislation is based on soft regulation, which means that it is not mandatory for companies to apply sustainability reporting assurance (SRA). Both listed and municipal corporations are affected by the new legislation. Based on positive accounting theory (PAT) and institutional theory (IT), it is possible that their different ownership identities will affect their choice of applying SRA. Purpose The purpose this study is to explain the relationship between ownership identity and SRA for Swedish companies. In addition, we will analyse factors that influence municipal corporations’ choice to apply or not to apply SRA. Method This quantitative study is based on a deductive approach. Based on PAT and IT, three hypothesis have been developed. A cross-sectional design has been used together with secondary data from companies’ annual reports in a logistic regression. Finally, we have developed our results from the logistic regression through four semi-structured interviews with employees from municipal corporations that are affected by the new legislation. Conclusion Ownership identity was not statistically significant in the logistic regression. However, our results should be read with some caution, since only three municipal corporations chose SRA. The results from the semi-structured interviews gave us some support for both PAT and IT. Moreover, our findings show a positive relationship between SRA and the control variables firm size and industry belonging.
34

Makrosäkring : Intressenters attityder till redovisning av dynamisk riskhantering / Macro Hedging : Stakeholders’ attitudes towards Accounting for Dynamic Risk Management

Andersson, Malin, Atterflod, Natalie January 2015 (has links)
Säkringsredovisning används vid redovisning av finansiella instrument som innehas i säkringssyfte. Det är svårt att tillämpa nuvarande regler för säkringsredovisning på makro-säkringar, särskilt när portföljer hanteras dynamiskt. På grund av begränsningarna i nuvarande säkringsredovisning har många företag svårt att tillförlitligt presentera resultatet av dynamisk riskhantering i de finansiella rapporterna. Effekten blir att vissa företag undviker att använda säkringsredovisning medan andra endast tillämpar säkringsredovisning till viss del. En del företag använder istället andra säkringstekniker som inte fullständigt återspeglar den dynamiska riskhanteringen. IASB har publicerat ett diskussionsunderlag (DP) som presenterar en redovisningsmetod för dynamisk riskhantering. Målet med den nya metoden Portfolio Revaluation Approach (PRA) är att uppnå en tillförlitlig presentation samt reducera den nuvarande operativa komplexiteten.Syftet med studien är att undersöka och jämföra IASB:s intressenters attityder till redovisning av dynamisk riskhantering och identifiera deras attityder till den föreslagna redovisnings-metoden PRA. Studien syftar dessutom till att kartlägga intressenternas attityder till hur en framtida metod bör utformas. I studien genomförs en kvalitativ innehållsanalys för att skapa en uppfattning av intressenternas attityder. Studien baseras på 30 remissvar som inkommit från intressenter som svar på IASB:s utgivna DP om makrosäkring. Intressentgrupperna som studien baseras på är normgivare, revisionsbolag och företag.Studien visar att intressenterna anser att det uppstår problem när nuvarande regler tillämpas på dynamiskt hanterade portföljer. IASB bör därför utveckla regler som återspeglar och blir tillämpbara på dynamisk riskhantering. Remissvaren visar dock att åsikterna om makro-säkringsprojektets omfattning och vad dynamisk riskhantering bör innefatta skiljer sig åt. IASB har frångått det initiala målet med projektet och utökat omfattningen. Intressenterna kräver därför att IASB tydliggör målet innan ett utkast (ED) utvecklas.Studien påvisar att åsikterna om PRA är skilda. Intressenterna har dock identifierat fler nackdelar än fördelar med PRA. Enligt intressenterna bör en framtida redovisningsmetod för dynamisk riskhantering endast tillämpas när riskerna har minimerats genom säkring och inte vid all dynamisk riskhantering. Intressenterna anser att en tillämpning på alla dynamiska riskhanteringsaktiviteter skulle öka resultatvolatiliteten och inte resultera i användbar information. Studien visar att en framtida redovisningsmetod för dynamisk riskhantering bör vara frivillig att tillämpa. Intressenterna anser att metoden bör utformas för att kunna tillämpas på alla risker, inte enbart ränterisker. Enligt intressenterna bör IASB inte utveckla en helt ny metod utan istället utforma en metod som bygger på befintliga regler i IFRS 9 Finansiella instrument och IAS 39 Finansiella instrument: Redovisning och värdering. IASB bör dessutom utforma principbaserade regler eftersom att den dynamiska riskhanteringen är föränderlig. IASB måste säkerställa att metoden är praktisk genomförbar. Vår slutsats är att intressenterna förvisso uppmuntrar IASB:s makrosäkringsprojekt men få är tillfredsställda med det som presenteras i DP. / Hedge accounting is used when accounting for financial instruments held for hedging purposes. There are difficulties associated with applying existing hedge accounting requirements to macro hedges particularly when portfolios are managed dynamically. Because of the limitations of existing hedge accounting many entities find it difficult to faithfully present the results of dynamic risk management in the financial statements. As a result, some entities do not apply hedge accounting at all while others only apply parts of hedge accounting. Some entities apply other hedging techniques which do not correctly reflect the dynamic risk management. The IASB has published a Discussion Paper (DP) featuring an accounting method for dynamic risk management. The objective of the new method Portfolio Revaluation Approach (PRA) is to achieve a faithful presentation of dynamic risk management and reduce the existing operational complexity.The purpose of the study is to examine and compare the attitudes of the IASB’s stakeholders towards accounting for dynamic risk management and identify their opinion on the proposed accounting method PRA. The study also aims to identify stakeholders’ views on how a future method should be designed. To obtain an understanding of stakeholders’ views a qualitative content analysis were used. The study is based on 30 comment letters received from stakeholders in response to the issued DP on macro hedging. The stakeholders where categorized into three groups: standard setting bodies, accounting firms and corporations.The study shows that stakeholders consider that problems arise when the current rules is applied to dynamically managed portfolios. The IASB should develop rules that will be applicable and reflect dynamic risk management. The comment letters shows different opinions about the scale of the project and what dynamic risk management should cover. The IASB has modified the initial objective of the project and expanded the scope. Stakeholders therefore require that the IASB clarifies the objective before they develop an Exposure Draft (ED).The study found that opinions on PRA are diverse. Stakeholders have, however, identified more disadvantages than advantages with PRA. According to stakeholders, a future accounting method for dynamic risk management should be applied only when risk mitigation has been undertaken by hedging and not applied on all dynamic risk management. Stakeholders believe that an application on all dynamic risk management activities would increase volatility in profit or loss and not result in useful information. Furthermore, the study shows that a method should be optional to apply. A future accounting method should be designed to be applicable to all risks, not only interest rate risks. Judging by the commentIIletters from the stakeholders, the IASB should not develop a new method but instead design a method based on the existing rules in IFRS 9 Financial instruments and IAS 39 Financial Instruments: Recognition and Measurement. Moreover, the IASB should develop principle-based rules because of the character of dynamic risk management. The IASB must ensure that the method is practicable. Our conclusion is that even though the stakeholders encourage the macro hedging project, few are satisfied with the proposal submitted.(This paper is written in Swedish)
35

Den (o)synliga Briseis : En komparativ litteraturanalys av relationen mellan Akilles, Patroklos och Briseis i Homeros Iliaden och Pat Barkers The Silence of the Girls

Ignatius, Henni January 2019 (has links)
The (in)visible Briseis. A comparative literary analysis of the relationship between Achilles, Patroclus and Briseis in Homer’s Iliad and Pat Barker’s The Silence of the Girls The purpose of this essay is to compare the relationship between Achilles and Patroclus in Homer’s Iliad (700s BC) and Pat Barker’s The Silence of the Girls (2019), while also looking into the role of Briseis and how the story differs when it is told from her point of view. Through the analysis I find that the relationship between Achilles and Patroclus have always been intense. I argue, however, that the intensity is given more depth and meaning when described from different perspectives, such as that of Briseis and Achilles himself, as is done in The Silence of the Girls. With the help of Kevin Goddard’s theory of the male gaze, the perspective of both Briseis and Achilles become invaluable for interpreting the relationship between the characters, as well as the characters themselves. For Achilles, the gaze of his mother influences him in a negative way in his relationship with Briseis, while the gaze of Patroclus causes changes in his mentality. I argue that this has to do with the Oedipus complex. For once, Briseis is not invisible and even though she continues to be the slave everyone expects her to be, she is, through the gaze, able to create her own story once that of Achilles ends. It is still the story of the great Achilles, but one in which he is also human.
36

Application of Process Analytical Technologies (PAT) tools in perfusion cultures: Development of Raman-based prediction models and optimization of IgG quantification through the ArgusEye® sensor / Tillämpning av Process Analytical Technologies (PAT) verktyg i perfusionskulturer: Utveckling av Raman-baserade prediktionsmodeller och optimering av IgG-kvantifiering genom ArgusEye®-sensorn

Rebellato Giordano Martim, Fernanda January 2024 (has links)
Monoklonala antikroppsbaserade läkemedel (mAb) är ett av de snabbast växande segmenten på läkemedelsmarknaden, främst på grund av deras tillämpning inom onkologi, immunologi och hematologi. Traditionellt sker den industriella produktionen av mAb med fed-batch-odling. Detta är en relativt lätthanterlig process med mAb-utbyten på 5-10 g/L, men dess brist på kontroll över kritiska processparametrar (CPP) orsakar höga mAb-förluster på grund av att kvalitetsspecifikationer inte uppfylls. Ökande marknadskrav och regulatoriska förändringar pådriver läkemedelsindustrin iinnovation inom mAb-tillverkningsprocessen, för att nå kontinuerlig tillverkning. För närvarande, som ett övergångssteg till kontinuerlig tillverkning, sker investeringar i intensifierade fed-batch-odlingar. Dessa uppnår högre celldensiteter på cirka 25-30 g/L, men detta är fortfarande mycket lägre än motsvarande mAb-koncentrationer på 130 g/L som kan uppnås med perfusionsprocesser. Andra fördelar med perfusionsprocesser är att de tillåter flexibla produktionsanläggningar och möjliggör en nivå av processkontroll som skulle tillåta realtidstestning av release. För att upprätthålla en perfusionsprocess under de specificerade förhållandena som garanterar den önskade mAb-kvaliteten, måste CPP kontrolleras noggrant. Process Analytical Technologies (PAT) kan mäta CPP i realtid på ett icke-destruktivt sätt. Denna studie undersökte tillämpningen av två PAT, ArgusEye®-sensorerna och Time-gated Raman-spektroskopi, på perfusionsprocesser. Vi visade att ArgusEye®-sensorerna kan användas för att mäta IgG i perfusionsprover med ganska bra korrelation med referensmetoden. Vi har också visat att multivariata Raman-baserade modeller kan konstrueras för att förutsäga flera CPP, baserat på samma spektra. Framförallt belyser denna studie komplexiteten i tillämpningen av dessa PAT för att kontrollera perfusionsprocesser. För ArgusEye® drar vi slutsatsen att för att få exakta mätningar måste vi ta hänsyn till förändringarna i koncentrationen av värdcellsprotein under en perfusionsprocess, eftersom deras ospecifika bindning till sensorerna är den troliga orsaken till variationen i IgG-mätningarna. För de Raman-baserade modellerna, visar denna studie att en stor mängd data krävs för att bygga korrekta prediktionsmodeller, något som rapprterats om i litteraturen. Sammantaget visar denna rapport att dessa PAT har en stor tillämpningspotential, men de måste förbättras ytterligare innan de kan användas som automatiska återkopplingskontrollverktyg. / Monoclonal antibody-based therapeutics (mAb) are one of the fastest-growing segments in the pharmaceutical market, mainly due to their application in oncology, immunology, and hematology. Traditionally, the industrial production of mAb is done with fed-batch cultivation. This is a relatively easy to operate process with mAb yields of 5-10 g/L, but its lack of control over critical process parameters (CPP) causes high mAb losses due to unmet quality specifications. Driven by increasing market demands and regulatory changes, the pharmaceutical industry is innovating in the mAb manufacturing process to reach continuous manufacturing. Currently, as a transition step to continuous manufacturing, the pharmaceutical industry is investing in intensified fed-batch cultivations. They achieve higher cells densities and present yields around 25-30 g/L, but this is still much lower than the equivalent mAb titers of 130 g/L that can be achieved with perfusion processes. Other advantages of perfusion processes are that they allow the existence of flexible production facilities and enable a level of process control that would permit Real-Time Release Testing. To maintain a perfusion process under the specified conditions to guarantee the desired mAb quality, the CPP need to be closely controlled. Process Analytical Technologies (PAT) can measure CPP in real-time and non-destructively. This study evaluated the application of two PAT, the ArgusEye® sensors and Time-gated Raman spectroscopy, on perfusion processes. We showed that the ArgusEye® sensors can be used to measure IgG in perfusion samples with quite good correlation to the reference method. We have also shown that multivariate Raman-based models can be constructed to predict several CPP based on the same spectra. Most importantly, this study highlights the complexity of the application of these PAT to control perfusion processes. For the ArgusEye®, we conclude that to obtain accurate measurements, we need to account for the changes in the concentration of host cell protein during a perfusion process, as their unspecific binding to the sensors is the probable cause for the variation in the IgG measurements. For the Raman-based models, as previously reported in the literature, this study shows that a high volume of data is require to build accurate prediction models. Overall, this report shows that these PAT have a great potential of application, but they need to be further improved prior to their use as automatic feedback control tools.
37

Développement d'une méthode PAT basée sur la technique NIR pour le suivi de l'uniformité d'un mélange particulaire pharmaceutique et l'évaluation de la taille moyenne des particules

Lapointe-Garant, Pierre-Philippe January 2009 (has links)
En 1992, le cas de Barr Laboratories vs. US Food and Drug Administration (FDA) est le sujet de l'heure dans l'industrie pharmaceutique. La FDA poursuit le manufacturier contractuel de produit pharmaceutique pour ses mauvaises pratiques de validation de procédés et de tests de routine. Le mélange des matières premières est particulièrement visé. Les procédures de validation y sont en effet négligées et les contrôles et évaluations de la qualité du produit fini sont alors restreints aux tests de quelques comprimés sur un lot parfois de plusieurs millions de comprimés. Un besoin est ainsi identifié : mettre en place un nouveau système d'évaluation de la qualité ou de contrôle de la production plus représentatif. C'est ainsi qu'en 2004 est lancée l'initiative des technologies d'analyse des procédés, ou"Process Analytical Technologies" ou PAT. Cette initiative, chapeautée par la FDA, prend rapidement de l'ampleur bien que restant à ce jour une recommandation plus qu'une loi. Dans la même veine, le projet de Recherche et Développement Coopératif (RDC) entre l'Université de Sherbrooke et Wyeth Pharmaceutiques sur l'étude des phénomènes granulaires d'écoulement et de ségrégation identifie ce même besoin important pour la continuation des travaux. C'est ainsi que naquit ce présent projet de maîtrise. Afin de faire suite aux recommandations de la FDA et afin de continuer les études sur les systèmes particulaires, un outil de suivi de la qualité en ligne doit être développé pour les mélangeurs utilisés dans l'industrie pharmaceutique. Cet outil devra éventuellement être viable pour la production de l'entreprise et servira de critère de relâche des produits finis. La technologie de la spectroscopie en proche infrarouge (NIR) a rapidement été identifiée pour ce besoin. Cette technologie possède les avantages nécessaires afin d'être installée sur le mélangeur et suivre la qualité de mélange en temps réel. Les travaux ici présentés ont été effectués entre janvier 2006 et septembre 2008 sur une véritable formulation pharmaceutique et ont été appliqués à l'échelle laboratoire tout comme à l'échelle de production conventionnelle. Les travaux ont permis d'identifier trois techniques d'analyse statistique viables pour le suivi de l'homogénéité de mélange en ligne : l'analyse de la variance, l'analyse de la distance et l'analyse quantitative. Ces trois techniques possèdent toutes leurs avantages et désavantages et le choix d'une de ces techniques dépend de la formule visée et du besoin du client. De plus, grâce à l'application d'un Design d'Expérience (DoE), les paramètres critiques ayant une influence sur le spectre NIR ont été évalués. La distribution de tailles de particules est un de ces facteurs ayant une influence importante. Son influence a été évaluée grâce à l'application du modèle de Kubelka-Munk. Les recommandations de ces travaux ont été transmises à l'entreprise Wyeth Pharmaceutiquess à Montréal et seront appliquées pour la future implantation de la technologie NIR pour le suivi de l'homogénéité de mélange lors des procédés de mélanges granulaires pharmaceutiques.
38

Calibration of multivariate predictive models the study of factors influencing the prediction ability of Raman spectroscopy applied to pharmaceutical tablets / Calibration des modèles prédictifs multivariés : étude des facteurs influant sur la prédiction de concentration de comprimés pharmaceutiques avec la spectroscopie Raman

Salvas, Joanny January 2010 (has links)
The use of Process Analytical Technology (PAT) is nowadays well spread throughout the pharmaceutical industry, mostly because they allow gaining useful process insight, better monitoring throughout the manufacturing steps, lowering costs associated with the use of wet-chemistry based testing method, and increasing overall efficiency. Most of the PAT methods are based on multivariate predictive models (MVPM).The calibration of such MVPM is a step crucial to the success of the MVPM-based PAT method development. From what could be gathered of today's practices in MVPM calibration, the current trends are aligned on the mantra"the more the better". This means that best-practices suggest that using more calibration points, with more samples, manufactured as closely as possible to the commercial samples, with more precise measuring reference methods, will lead to a more precise, better performing MVPM-based PAT methods. Obviously, it also leads to a costlier and longer to develop method, thus limiting the potential applications as well as lowering the overall gain to expense ratio of these methods.The aim of this work was to investigate the development protocol of MVPM-based PAT methods in order to identify the factors that were most susceptible to influence the performances of the developed method, with the ultimate goal to propose an optimized protocol. A base case of MVPM-based PAT method was used to perform the assessment: the use of Raman spectra collected from intact pharmaceutical tablets to predict their content in 4 minerals and 1 vitamin. From this development case study, two minerals were chosen to be part of the investigation: one that was in high concentration in the product and one that was in low concentration. Eight (8) factors were identified and tested separately on the two data sets created.The tests were guided by a design of experiment that allowed optimizing the total number of predictive models that needed to be made, all the while retaining sufficient data to allow minimal confusions within second-order factorial interactions. Analysis of results gathered from more than 85 multivariate predictive models allowed identifying factors that had an influence on both type of calibration (high and low raw material concentration).The type of equipment and batch size used for calibration samples manufacturing, as well as the number of points and replicates use (to a certain extent) or the calibration algorithm and reference method did not influence the MVPM accuracy when dealing with highly concentrated raw material. For a low-concentration raw material, the significant factors were the type of equipment and number of calibration points used. In both cases, the distribution of the calibration points along the chosen concentration span showed a significant influence on the method performances. Having identified the factors influencing the MVPM-based PAT method, an optimized protocol for future development could be proposed. Using this alternate approach should reduce the required invested man- and lab-time by approximately 30 %. A 31 % reduction in development-related costs is also expected. These results can be achieved with a manageable accuracy decrease varying between 0 and less than 2 % (absolute values), depending on the type of raw material concentration monitored. This study fills a gap in the published literature. No extensive and comprehensive studies had been made, to the author's knowledge, regarding the overall development process of such MVPM-based methods. Several hints for future research and developments are also proposed to follow-up with this project.
39

Optimisation de l'utilisation d'un spectromètre proche infrarouge pour le suivi de l'humidité d'une poudre pharmaceutique lors du séchage dans un lit fluidisé

Demers, Anne-Marie January 2011 (has links)
Le contrôle de la qualité est une étape critique lors de la fabrication de produits pharmaceutiques. Pour accomplir cette tâche, différentes méthodes de laboratoire peuvent être utilisées, mais celles-ci sont habituellement coûteuses et exigent beaucoup de temps. Une alternative suggérée par l'agence réglementaire Food and Drug Administration est l'utilisation d'outils permettant l'analyse en continu, dont entre autres les outils spectroscopiques comme le proche infrarouge par exemple. Une des applications de cette technologie est le suivi de l'humidité d'une poudre pharmaceutique lors de son séchage dans un lit fluidisé. Une sonde à réflectance, qui est attachée au spectromètre, est insérée dans le bol du lit fluidisé et des spectres sont acquis tout au long du procédé. L'interprétation des spectres obtenus nécessite toutefois l'application de l'analyse multivariée et l'utilisation de plusieurs tests statistiques. Une courbe de calibration peut ainsi être construite et être utilisée au lieu des tests réalisés au laboratoire. Néanmoins, les paramètres critiques du spectromètre peuvent influencer la performance de la courbe de calibration bâtie. Par ailleurs, les articles publiés sur le sujet d'intérêt mentionnent que l'emplacement de la sonde, c'est-à-dire son angle et sa hauteur dans le bol, est critique pour l'obtention d'une acquisition spectrale de qualité. Or, aucun article n'a été publié sur la détermination de cet emplacement optimal et aussi sur le type d'embout à utiliser pour s'assurer d'une bonne lecture spectrale. Tout d'abord, des courbes de calibration ont été construites pour deux produits différents, soient un supplément vitaminé et un anti-inflammatoire. La méthodologie utilisée pour ces modélisations chimiométriques était innovatrice, car seulement des échantillons provenant de l'usine étaient utilisés et les spectres acquis avec le spectromètre étaient répliqués pour chaque échantillon collecté. Par la suite, un embout permettant une acquisition spectrale de qualité a été conçu et le nombre moyen de scans/spectre a été déterminé. En ayant fixé ces deux paramètres, la performance de la courbe de calibration construite pour le supplément vitaminé a été évaluée dans le lit fluidisé dans un environnement de production. Enfin, des plans d'expériences réalisés dans le lit fluidisé au laboratoire avec les deux produits ont permis d'évaluer l'effet des paramètres critiques du spectromètre sur les performances des courbes de calibration. Les tests statistiques effectués sur les deux courbes de calibration montrent de bonnes corrélations entre les prédictions par le spectromètre et les valeurs de référence. Par ailleurs, les essais réalisés dans un environnement de production ont démontré qu'un embout comportant une cavité permettant à la poudre de se stabiliser ainsi qu'un faible nombre de scans/spectre assurent une acquisition spectrale de qualité. Uniquement la courbe de calibration construite pour le supplément vitaminé a été évaluée dans un environnement de production ; le modèle chimiométrique réussit à bien prédire la fin de séchage. Enfin, les conclusions obtenues suite aux plans d'expériences réalisés dans le lit fluidisé au laboratoire ne peuvent pas être généralisées à différents produits. Il a aussi été démontré qu'il est difficile d'acquérir des spectres en mode dynamique et d'interpréter les résultats associés aux réplicas d'essais. Des travaux futurs sont suggérés pour investiguer certaines questions suscitées par cette recherche.
40

Process monitoring and control using live cell imaging for the manufacturing of cell therapies

Smith, David January 2014 (has links)
Regenerative medicine (RM) represents a promising enabling technology to revolutionize healthcare. This said there are still major gaps between the commercial promise and the reality of the cell therapy sector of regenerative medicine. There is consensus to develop high through-put, automated technologies for the manufacture of RM products. Imaging methods will have the capacity to contribute to this technological gap for cell therapies and are particularly attractive to provide non-destructive monitoring with high spatial and temporal resolution. This work applied an automated, non-invasive phase contrast imaging platform (Cell-IQ) to measure, analyse and ultimately quantify image derived metrics for human embryonic stem cells (hESCs) and haematopoietic stem cells (HSCs) as part of the colony forming unit (CFU) assay. This work has shown through thresholding and machine vision identification technology, imaging has the ability to improve the precision of current evaluation methods for cell culture, providing novel information regarding culture state and show image derived metrics to be predictive of future culture state. Building on this, differentiation through the addition of a growth factor cocktail highlighted how in-process monitoring enables protocol optimisation. After equilibrating the Cell-IQ incubator to a standard incubator, the progress of the CFU assay was monitored and image metrics representative of colony phenotype were analysed. Cell count, distance between cells and cell migration within individual colonies were identified to be informative and provide a degree of colony phenotype separation. Quantitative, novel, image derived metrics were identified that improve reliability through computer automation, cost by removing user verification and time by reducing the assay time from 14 days to 7 days. Non-invasive imaging provides a fantastic opportunity to create bespoke sampling frequencies to achieve desired precision for manufacturing cell therapies, this work has developed and shown improvement and a level of control to current culture process for ESCs and HSCs.

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