• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 44
  • 7
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 70
  • 28
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 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.
61

Genomic architecture of sickle cell disease clinical variation in children from West Africa : a case-control study design

Quinlan, Jacklyn 08 1900 (has links)
Contexte : L’anémie falciforme ou drépanocytose est un problème de santé important, particulièrement pour les patients d’origine africaine. La variation phénotypique de l’anémie falciforme est problématique pour le suivi et le traitement des patients. L’architecture génomique responsable de cette variabilité est peu connue. Principe : Mieux saisir la contribution génétique de la variation clinique de cette maladie facilitera l’identification des patients à risque de développer des phénotypes sévères, ainsi que l’adaptation des soins. Objectifs : L’objectif général de cette thèse est de combler les lacunes relatives aux connaissances sur l’épidémiologie génomique de l’anémie falciforme à l’aide d’une cohorte issue au Bénin. Les objectifs spécifiques sont les suivants : 1) caractériser les profils d’expressions génomiques associés à la sévérité de l’anémie falciforme ; 2) identifier des biomarqueurs de la sévérité de l’anémie falciforme ; 3) identifier la régulation génétique des variations transcriptionelles ; 4) identifier des interactions statistiques entre le génotype et le niveau de sévérité associé à l’expression ; 5) identifier des cibles de médicaments pour améliorer l’état des patients atteints d’anémie falciforme. Méthode : Une étude cas-témoins de 250 patients et 61 frères et soeurs non-atteints a été menée au Centre de Prise en charge Médical Intégré du Nourrisson et de la Femme Enceinte atteints de Drépanocytose, au Bénin entre février et décembre 2010. Résultats : Notre analyse a montré que des profils d’expressions sont associés avec la sévérité de l’anémie falciforme. Ces profils sont enrichis de génes des voies biologiques qui contribuent à la progression de la maladie : l’activation plaquettaire, les lymphocytes B, le stress, l’inflammation et la prolifération cellulaire. Des biomarqueurs transcriptionnels ont permis de distinguer les patients ayant des niveaux de sévérité clinique différents. La régulation génétique de la variation de l’expression des gènes a été démontrée et des interactions ont été identifiées. Sur la base de ces résultats génétiques, des cibles de médicaments sont proposées. Conclusion: Ce travail de thèse permet de mieux comprendre l’impact de la génomique sur la sévérité de l’anémie falciforme et ouvre des perspectives de développement de traitements ciblés pour améliorer les soins offerts aux patients. / Background: Sickle Cell Disease (SCD) is an important public health issue, particularly in Africa. Phenotypic heterogeneity of SCD is problematic for follow-up and treatment of patients. Little is known about the underlying genomic architecture responsible for this variation. Rationale: Understanding the genetic contribution to the inter-patient variability will help in identifying patients at risk of developing more severe clinical outcomes, as well as help guide future developments for treatment options. Objectives: To characterize genome-wide gene expression patterns associated with SCD clinical severities and to identify genetic regulators of this variation. More specifically, our objectives were to associate gene expression profiles with SCD severity, identify transciptional biomarkers, characterise the genetic control of gene expression variation, and propose drug targets. Methods: A case-control population of 250 SCD patients and 61 unaffected siblings from the National SCD Center in Benin were recruited. Genome-wide gene expression profiles and genotypic data were generated. Results: Genome-wide gene expression patterns associated with SCD clinical variation were enriched in B-lymphocyte development, platelet activation, stress, inflammation and cell proliferation pathways. Transcriptional biomarkers that can discriminate SCD patients with respect to clinical severities were identified. Hundreds of genetic regulators were significantly associated with gene expression variation and potential drug targets are suggested. Conclusion: This work improves our understanding of the biological basis of SCD clinical variation and has the potential to guide development of targeted treatments for SCD patients.
62

Content repurposing of electrical diagrams for presentation in handheld devices

Papaliakos, Vasilios 12 1900 (has links)
Approved for public release, distribution is unlimited / This thesis proposes a design for content repurposing of electrical diagrams for presentation in small-screen wireless handheld devices. Content repurposing is the on-line adaptation of content to fit device capabilities and user's preferences. The focus of this thesis is on electrical diagrams of the schematic type used for maintenance purposes. Nevertheless, many of the proposed techniques are suitable for other technical drawings as well. A significant amount of work has been done in summarization of Web documents and in diagram recognition, but not for presentation of diagrams in handheld devices. In the design proposed here, techniques are proposed for understanding the semantics of electrical diagrams and for partitioning the drawing images in intelligent ways to formulate coherent units for presentation to the user. / Lieutenant, Hellenic Navy
63

The Second-Hand Society

Cooke, Christina Elizabeth 01 January 2011 (has links)
The Second-Hand Society tells the stories of people in Portland, Oregon who redefine waste by making use of objects others discard. The author spends time in repair shops watching craftsmen hammer and polish broken typewriters, vacuum cleaners and shoes back to life. She follows book scouts, clothes pickers and liquidators as they gather merchandise to resell and spends hours at nonprofits that collect and redistribute unwanted electronics and building supplies. She watches junk artists and fashion designers assemble found objects into display pieces, accompanies Dumpster divers and "freegans" along their regular collection routes and visits the homeless encampment by the airport to see how an entire community of people survives on nothing but reclaimed materials. The members of the second-hand society challenge the traditional conception of things as "broken" or "unwanted" and assert that forward movement and new-new-new is not always optimal. By examining the motivations and practices of the people who make use of our discards and looking at the contradictions they run up against, this thesis develops a more complete understanding of the reality that's possible if we think differently about our waste.
64

Pathway-centric approaches to the analysis of high-throughput genomics data

Hänzelmann, Sonja, 1981- 11 October 2012 (has links)
In the last decade, molecular biology has expanded from a reductionist view to a systems-wide view that tries to unravel the complex interactions of cellular components. Owing to the emergence of high-throughput technology it is now possible to interrogate entire genomes at an unprecedented resolution. The dimension and unstructured nature of these data made it evident that new methodologies and tools are needed to turn data into biological knowledge. To contribute to this challenge we exploited the wealth of publicly available high-throughput genomics data and developed bioinformatics methodologies focused on extracting information at the pathway rather than the single gene level. First, we developed Gene Set Variation Analysis (GSVA), a method that facilitates the organization and condensation of gene expression profiles into gene sets. GSVA enables pathway-centric downstream analyses of microarray and RNA-seq gene expression data. The method estimates sample-wise pathway variation over a population and allows for the integration of heterogeneous biological data sources with pathway-level expression measurements. To illustrate the features of GSVA, we applied it to several use-cases employing different data types and addressing biological questions. GSVA is made available as an R package within the Bioconductor project. Secondly, we developed a pathway-centric genome-based strategy to reposition drugs in type 2 diabetes (T2D). This strategy consists of two steps, first a regulatory network is constructed that is used to identify disease driving modules and then these modules are searched for compounds that might target them. Our strategy is motivated by the observation that disease genes tend to group together in the same neighborhood forming disease modules and that multiple genes might have to be targeted simultaneously to attain an effect on the pathophenotype. To find potential compounds, we used compound exposed genomics data deposited in public databases. We collected about 20,000 samples that have been exposed to about 1,800 compounds. Gene expression can be seen as an intermediate phenotype reflecting underlying dysregulatory pathways in a disease. Hence, genes contained in the disease modules that elicit similar transcriptional responses upon compound exposure are assumed to have a potential therapeutic effect. We applied the strategy to gene expression data of human islets from diabetic and healthy individuals and identified four potential compounds, methimazole, pantoprazole, bitter orange extract and torcetrapib that might have a positive effect on insulin secretion. This is the first time a regulatory network of human islets has been used to reposition compounds for T2D. In conclusion, this thesis contributes with two pathway-centric approaches to important bioinformatic problems, such as the assessment of biological function and in silico drug repositioning. These contributions demonstrate the central role of pathway-based analyses in interpreting high-throughput genomics data. / En l'última dècada, la biologia molecular ha evolucionat des d'una perspectiva reduccionista cap a una perspectiva a nivell de sistemes que intenta desxifrar les complexes interaccions entre els components cel•lulars. Amb l'aparició de les tecnologies d'alt rendiment actualment és possible interrogar genomes sencers amb una resolució sense precedents. La dimensió i la naturalesa desestructurada d'aquestes dades ha posat de manifest la necessitat de desenvolupar noves eines i metodologies per a convertir aquestes dades en coneixement biològic. Per contribuir a aquest repte hem explotat l'abundància de dades genòmiques procedents d'instruments d'alt rendiment i disponibles públicament, i hem desenvolupat mètodes bioinformàtics focalitzats en l'extracció d'informació a nivell de via molecular en comptes de fer-ho al nivell individual de cada gen. En primer lloc, hem desenvolupat GSVA (Gene Set Variation Analysis), un mètode que facilita l'organització i la condensació de perfils d'expressió dels gens en conjunts. GSVA possibilita anàlisis posteriors en termes de vies moleculars amb dades d'expressió gènica provinents de microarrays i RNA-seq. Aquest mètode estima la variació de les vies moleculars a través d'una població de mostres i permet la integració de fonts heterogènies de dades biològiques amb mesures d'expressió a nivell de via molecular. Per il•lustrar les característiques de GSVA, l'hem aplicat a diversos casos usant diferents tipus de dades i adreçant qüestions biològiques. GSVA està disponible com a paquet de programari lliure per R dins el projecte Bioconductor. En segon lloc, hem desenvolupat una estratègia centrada en vies moleculars basada en el genoma per reposicionar fàrmacs per la diabetis tipus 2 (T2D). Aquesta estratègia consisteix en dues fases: primer es construeix una xarxa reguladora que s'utilitza per identificar mòduls de regulació gènica que condueixen a la malaltia; després, a partir d'aquests mòduls es busquen compostos que els podrien afectar. La nostra estratègia ve motivada per l'observació que els gens que provoquen una malaltia tendeixen a agrupar-se, formant mòduls patogènics, i pel fet que podria caldre una actuació simultània sobre múltiples gens per assolir un efecte en el fenotipus de la malaltia. Per trobar compostos potencials, hem usat dades genòmiques exposades a compostos dipositades en bases de dades públiques. Hem recollit unes 20.000 mostres que han estat exposades a uns 1.800 compostos. L'expressió gènica es pot interpretar com un fenotip intermedi que reflecteix les vies moleculars desregulades subjacents a una malaltia. Per tant, considerem que els gens d'un mòdul patològic que responen, a nivell transcripcional, d'una manera similar a l'exposició del medicament tenen potencialment un efecte terapèutic. Hem aplicat aquesta estratègia a dades d'expressió gènica en illots pancreàtics humans corresponents a individus sans i diabètics, i hem identificat quatre compostos potencials (methimazole, pantoprazole, extracte de taronja amarga i torcetrapib) que podrien tenir un efecte positiu sobre la secreció de la insulina. Aquest és el primer cop que una xarxa reguladora d'illots pancreàtics humans s'ha utilitzat per reposicionar compostos per a T2D. En conclusió, aquesta tesi aporta dos enfocaments diferents en termes de vies moleculars a problemes bioinformàtics importants, com ho son el contrast de la funció biològica i el reposicionament de fàrmacs "in silico". Aquestes contribucions demostren el paper central de les anàlisis basades en vies moleculars a l'hora d'interpretar dades genòmiques procedents d'instruments d'alt rendiment.
65

ANTIBACTERIAL DRUG DEVELOPMENT TARGETING GUT PATHOGENS

Ahmed A Hassan (8556792) 01 May 2020 (has links)
<p>Over three million infections were reported in the United States of America in 2019. These infections were caused by either antibiotic-resistant pathogens or <i>Clostridioides difficile</i> and resulted in more than 50,000 deaths. Unfortunately, antibacterial agents are rapidly losing their ability to treat infections and the process of discovering new antibiotics is too slow to cope up with bacterial evolution. Repurposing FDA-approved drugs of well-studied safety, pharmacology and pharmacokinetics represents a faster alternative method of antibacterial drug discovery. Repurposing is more successful and less depleting method of drug discovery than classical de novo method in regard to both cost and time. In the following studies, two major pathogens are targeted, vancomycin-resistant <i>Enterococcus</i> (VRE) and <i>C. difficile</i>. Both bacteria are more prevalent in healthcare settings were more vulnerable population of elderly and immunocompromised individuals reside. In addition, healthcare settings are usually associated with higher frequency of receiving antibiotics which in turn, compromises the integrity of normal microbiota responsible for protection against invading pathogens. Furthermore, hospital stays are associated with exposure to bacterial shedding from other patients. Our aim was to identify FDA-approved drugs with novel ability to eradicate these two bacterial pathogens in the gastrointestinal tract (GIT). Notably, the GIT is considered the actual site of infection in case of <i>C. difficile while it is only a transition site for VRE where the bacteria colonize before causing true infections in other tissues. Studies against both bacteria started with an <i>in vitro</i> screening of FDA-approved drugs and clinical molecules to identify potential candidates for further investigation.</i></p><p><i>For VRE, two drugs where identified with potent inhibitory activity and favorable pharmacokinetic profiles, auranofin and ebselen. Auranofin was approved in the 1960s for the treatment of rheumatoid arthritis due to its anti-inflammatory activity. Auranofin was found to exert potent bacteriostatic activity against both vancomycin-sensitive and vancomycin-resistant <i>Enterococcus</i> strains (minimum inhibitory concentration against 90% of the strains, MIC90 = 1 µg/mL). In addition, bacteria could not develop resistant mutants against auranofin upon prolonged exposure. On the other hand, ebselen is an organoselenium compounds currently in clinical trials for several indications. Similarly, ebselen was found to be a potent inhibitor of VRE growth (MIC90 = 2 µg/mL). In addition, ebselen successfully inhibited bacterial biofilm formation and eradicated mature biofilms. In a mouse model of VRE colonization, both drugs inhibited bacterial shedding and reduced bacterial counts in the GIT of the colonized animals.</i></p><p><i>For <i>C. difficile</i>, auranofin was also found to exert potent inhibitory activity against bacterial growth (MIC90 = 2 µg/mL), toxin production and spore formation. Additionally, it was beneficial in protecting colon cells against <i>C. difficile</i> toxin-induced inflammation. Further, auranofin was found to not promote growth of VRE as seen with the current anticlostridial agents. In addition to auranofin, two more antiprotozoal drugs were found to potently inhibit <i>C. difficile</i> growth, ronidazole and secnidazole. Both drugs are 5-nitroimidazoles approved for human (secnidazole) or veterinary (ronidazole) applications. Secnidazole and ronidazole halted <i>C. difficile</i> growth at very low concentrations (MIC90 = 0.5 and 0.125 µg/mL, respectively). Furthermore, both drugs were superior to metronidazole in bacterial killing and had favorable activities against protective gut microbiota. In addition, they demonstrated efficient protection to mice in a <i>C. difficile</i> infection model. </i></p><p><i>Overall, several drugs were presented to possess favorable activities against <i>C. difficile</i> or VRE. These drugs merit more evaluation as potential candidates for the treatment of infection caused by either bacteria. </i></p><div><i><br></i></div>
66

Information Overload: Reading Information-as-Waste in Contemporary Canadian Literature

Speranza, Monica 29 June 2021 (has links)
This thesis investigates three contemporary Canadian texts— Ruth Ozeki’s A Tale for the Time Being, Margaret Atwood’s Oryx and Crake, and Rita Wong’s forage—that treat information as an object that can be wasted and recuperated. Using information theory and a new sub-field of critical waste theory called “Discard Studies,” I explore how the authors studied in this thesis place these two lines of thought alongside one another to examine how the concept of recycling information challenges the material, cultural, and ideological structures that distance humans from their waste. Specifically, I read the event of recycling as an interruptive act that triggers a reassessment of the (im)material connections that tether humans to their waste, vast (inter)national networks of exchange, and environmental crises related to our garbage.
67

Implication du métabolisme de la sérotonine dans les cancers du sein triple négatifs et perspectives cliniques / Implication of Serotonin Metabolism in Triple Negative Breast Cancers and Clinical Perspectives

Marques Pinheiro, Alice 20 September 2019 (has links)
Les cancers triple négatif (TN) représente la forme la plus agressive des cancers du sein, avec un pourcentage de décès importants. Il existe une grande hétérogénéité au sein de cette maladie en termes de présentation clinique initiale, de caractéristiques biologiques, de sensibilité au traitement et d’évolution. Aucun progrès en survie n’a été réalisé depuis l’avènement des protocoles de chimiothérapie standards. En effet, malgré une bonne réponse initiale au traitement, 65% des patientes résistent aux thérapies actuelles et récidivent ce qui leur confère un pronostic particulièrement sombre. Il y a donc urgence à identifier de nouveaux protocoles de traitement et de nouvelles molécules efficaces pour ces patientes.Une stratégie de plus en plus intéressante actuellement est celle du repositionnement de composés médicaux qui n’étaient initialement pas destinés au traitement d’une maladie donnée. Cette approche a pour avantage de profiter de l’effort de recherche et développement initial extrêmement couteux et de profiter des études pharmacologiques déjà disponibles. J’ai ainsi effectué au cours de ma thèse un criblage de composés chimiques à haut débit sur 12 lignées de cancers du sein TN afin de prendre en compte leur hétérogénéité. A l’issue de ce crible, plusieurs composés se sont avérés intéressants de par leur potentiel anti-cancéreux. Plus particulièrement, des molécules psychoactives impliquées dans le métabolisme de la sérotonine (ie antidépresseurs, et notamment les inhibiteurs de recapture de la sérotonine-SSRI) sont apparues comme des « hits » forts.Suite à ces résultats, mon travail de thèse s’est orienté plus particulièrement vers la compréhension de l’activité de ces molécules et du métabolisme de la sérotonine dans nos modèles TN afin de comprendre pourquoi ces composés pouvaient présenter un intérêt dans le traitement de ces cancers. Différents aspects biologiques ont ainsi été investigués pour ces antidépresseurs. J’ai ainsi étudié le rôle exercé par la sérotonine sur mes modèles cellulaires. D’autre part, j’ai entrepris une cartographie des acteurs du métabolisme de la sérotonine afin de caractériser mes modèles. J’ai ainsi découvert deux récepteurs à la sérotonine majoritairement présents, HTR1D et HTR1B, qui ont fait l’objet de recherches approfondies. J’ai ainsi pu démontrer l’intérêt de ces deux récepteurs comme cibles thérapeutiques potentielles dans les cancers triple négatifs. Grace à une étude rétrospective j’ai pu mettre en évidence une corrélation statistiquement significative entre le niveau d’expression de chacun de ces deux récepteurs et la survie des patientes TN. Nous observons ainsi une nette discrimination entre les deux groupes de cancers exprimant peu ou fortement ces gènes. J’ai ainsi pu mettre en évidence que ces deux récepteurs représentent des biomarqueurs pronostics forts des patientes TN. L’étude immunohistochimique, a permis de confirmer la présence de ces récepteurs dans les tumeurs TN. Par ailleurs, j’ai pu identifier un micro ARN régulant l’expression de l’un des récepteurs dans les lignées TN. De façon cohérente, j’ai pu observer un effet pronostic significatif du niveau d’expression de ce micro ARN sur la survie des patientes TN. L’efficacité des composés de type SSRI et d’un antagoniste de nos deux récepteurs a pu être vérifiée sur des cultures ex vivo issues de PDX notamment résistantes aux chimiothérapies. L’évaluation préclinique de ces composés a pu être testée sur un premier modèle murin TN de type PDX mais n’a cependant pas permis de démontrer d’efficacité antitumorale in vivo. En effet, la complexité du métabolisme de la sérotonine, tout comme l’hétérogénéité biologique des TN requièrent des études plus approfondies afin de pouvoir faire la preuve de concept du ciblage thérapeutique de ces récepteurs et de la modulation du métabolisme de la sérotonine dans ces cancers. Ce travail fait l’objet d’un manuscrit en préparation pour publication dans le cadre de cette thèse. / Triple negative breast cancer (TNBC) is the most aggressive form of breast cancers. It accounts for 15-20% of breast cancers. No progress in survival has been achieved since the advent of standard chemotherapy protocols. TNBC is an important clinical challenge. They have the worst outcome among breast cancer subgroups. Given their poor prognosis, their assumed hetetogeneity, and absence of any alternative specific targeted therapy, chemotherapy remains the only TNBC treatment. Despite an often good initial response to treatment, more than a half of patients do not achieve a pathological complete response, with a frequent and fast tumor relapse. Several therapeutic approaches have been identified preclinically, but none of these molecules have been shown to be effective on all of these patients. There is a urge for the identification of new treatments.An interesting strategy is the repurposing of medical compounds that were initially not intended for the treatment of a given disease. This strategy takes advantage of the extremely expensive initial research and development effort. This process is potentially efficient and cost-effective as previous clinical trials have been performed and pharmacokinetics/pharmacodynamics and toxicity have been already explored. In order to develop new treatment schemes we addressed the following question: Is there available drugs with strong activity in TNBC? To do so, we performed a high-throughput drug screening on 12 TNBC cell lines to reflect the dramatic heterogeneity of the disease. From this drug discovery program, several interesting compounds were identified with significant anti-tumor potential against TNBC. More particularly, psychoactive compounds regulating serotonin metabolism (ie antidepressant drugs and notably serotonin selective reuptake inhibitors-SSRIs) were found to be highly effective “hits”.My thesis work turned to the comprehension of serotonin implication in TNBC physiopathology to understand if modulating its metabolism could be of therapeutic interest for TNBC management. Different biological aspects were investigated concerning serotonin effects on TNBC cellular models (serotonin adjunction in vitro or endogenous synthesis inhibition). In addition, I established a comprehensive map of the serotonergic landscape in TNBC (biosynthetic capacity, transporters, receptors) that led to the identification of therapeutic targets that would be of interest in the treatment of cancer: HTR1D and HTR1B. Indeed, by blocking these promising targets (with chemical inhibitors or siRNA knockdown) we observed a strong reduction in cell viability in our large panel of TNBC cell lines. Remarkably, we found that their expression levels were associated to poor prognosis in breast cancer, and notably in TNBC subtype with huge dichotomy observed in the outcome, allowing future stratification of TNBC patient management and selection for further targeted therapies. These results pinpoint HTR1D and HTR1B as strong prognosis biomarkers in TNBC. Immunohistochemistry staining was also conducted to confirm the presence of these targets at the protein level in tumor samples. Moreover, I could identify a microRNA regulating one of these receptors: has-miR-599. Consistently, expression levels of this microRNA demonstrated a prognostic impact on TNBC survival. While ex vivo data of one SSRI and the dual antagonist of HTR1D/HTR1D receptors shown encouraging efficacy, their preclinical evaluation assessed in a TN PDX model could not allow to demonstrate any significant effect on tumor growth in vivo. As a matter of fact, serotonin metabolism is a complex system and TNBC heterogeneity does not permit to conclude on the therapeutic proof of concept of the serotonergic modulation in TNBC with this first attempt. A scientific manuscript of this work is being prepared for publication.
68

Impact of the EU Battery Regulation on Circular Economy of EV Batteries- barriers and opportunities for battery repurposing

Chun Lin, Yi January 2023 (has links)
This thesis presents a comprehensive exploration of the impact of EU battery regulations, Regulation (EU) 2023/1542, on end-of-life batteries, focusing on repurposing within the supply chain. We used both surveys and interviews to gather qualitative data from the stakeholders in the battery supply chain. These interviews dug deeper into aspects that the survey couldn´t fully capture, helping us better understand how EU regulations affect the supply chain. Results revealed a nuanced reality where EU regulations offer advantages by defining producer responsibilities, enhancing safety standards, and enabling data sharing. However, unintended consequences include competitive dynamics that may favor recycling over repurposing. Technical and organizational challenges, such as non-standardized battery designs and uncertainties regarding repurposed battery lifespans, also emerged. Various circular business models were explored under this environment, each requiring a functional value network and effective coordination among stakeholders. Overall this research contributes valuable insights as the EU seeks circularity in the battery supply chain. By addressing barriers, seizing opportunities, and fostering collaboration, it supports a sustainable and circular future in the EV battery chain, maximizing the value of initial investment and aligning with the goals of the energy transition. / Detta examensarbete presenterar en undersökning av effekten av EU:s batteriförordningar, förordning (EU) 2023/1542 som reglerar batterier vid livscykelns slut med fokus på återanvändning inom försörjningskedjan. Både enkäter och intervjuer använder för att samla in kvalitativa data från intressenter i batteriförsörjningskedjan. Intervjuerna gick djupare in på aspekter som enkäten inte kunde fånga fullt ut, vilket hjälpte oss att bättre förstå hur EU-förordningar påverkar försörjningskedjan. Resultaten avslöjade en nyanserad verklighet där EU-förordningarna erbjuder fördelar genom att definiera producentansvar, förbättra säkerhetsstandarder och möjliggöra datadelning. Dock uppstår oavsiktliga konsekvenser såsom konkurrensdynamik som kan främja återvinning framför återanvändning. Tekniska och organisatoriska utmaningar, såsom icke-standardiserade batteridesign och osäkerheter angående återanvända batteriers livslängd, framkom också. Olika cirkulära affärsmodeller utforskades i denna kontext, som alla förutsätter ett fungerade värdenätverk och effektiv samordning mellan intressenterna. Sammanfattningsvis bidrar denna forskning med värdefulla insikter i EU:s fortsatta strävan efter cirkularitet i batteriförsörjningskedjan. Genom att uppmärksamma hinder, utnyttja möjligheter och främja samarbete, stödjer forskningen en hållbar och cirkulär framtid i försörjningskedjan för elbilsbatterier. Detta maximerar värdskapandet från de ursprungliga investeringarna och ligger i linje med målen för energiövergången.
69

Återbruk och återgivning : Om att finna det nya i det gamla och det imaginära ur det materiella

Hillborg, Linus January 2021 (has links)
Detta arbete består av ett antal verk skapade med olika återbrukade teknologier och de kompositionsmetoder som uppstår till följd av deras begränsningar, samt en text som behandlar verken utifrån några definitioner av mediearkeologisk konstnärlig praktik som föreslagits av medieteoretikern Jussi Parikka. Verken – Orphan Works, Magelungsverket och Temporal Canons: No. 1 - 3 – utgör den konstnärliga delen av arbetet. Texten tar även upp tankar om bl.a. mitt eget användande av teknik och betydelsen det haft för mitt skapande, att finna det suggestiva genom att utforska det materiella i skapandet, sociala och ekologiska aspekter av automatisering och moderna musikteknologier, olika nivåer av återbruk i konstnärligt syfte, alternativa historier och imaginära medier, konstverks livslängd under snabb teknikutveckling samt ljudåtergivning i relation till dessa.
70

Caractérisation des activités épigénétiques et anticancéreuses de la proscillaridine A dans les cancers pédiatriques

Da Costa, Elodie 11 1900 (has links)
Les glycosides cardiotoniques sont des inhibiteurs des pompes sodium / potassium utilisés pour le traitements des insuffisances cardiaques, qui détiennent également des activités anticancéreuses et épigénétiques récemment caractérisées. Toutefois, dans l’objectif de repositionner ces médicaments comme traitement anticancéreux, les mécanismes sousjacents aux activités anticancéreuses et épigénétiques des glycosides cardiotoniques restent à être déterminés. Dans nos travaux, nous révélons que la proscillaridine A est le glycoside cardiotonique qui détient des activités anticancéreuses et épigénétiques les plus puissantes dans des lignées de cancer du côlon, de leucémies et de sarcomes pédiatrique. De plus, nous avons identifié que l’activité anticancéreuse de la proscillaridine A corrèle positivement avec le niveau d’expression protéique du proto-oncogène MYC dans un panel de 14 lignées cellulaires cancéreuses. Dans les lignées cellulaires exprimants un haut niveau de MYC telles que les lignées leucémiques, la proscillaridine A agit comme un inhibiteur de MYC et module sa stabilité protéique ainsi que la régulation transcriptionnelle et translationnelle de ces cibles. Cette inhibition est induite par la baisse significative de l’expression des enzymes épigénétiques les lysines acétyltransférases (KATs), qui contrôlent l’ajout des résidus d’acétylcoenzyme A sur les histones et sur d'autres protéines dont MYC. La baisse d’expression des KATs résultent à une baisse de l’acétylation des résidus de l’histone 3 et à une reprogrammation de l’acétylome des cellules cancéreuses surexprimant MYC. Ces changements au niveau de la chromatine induisent une reprogrammation transcriptionnelle et phénotypique des cellules surexprimant MYC, qui se traduit par une perte de la transcription des programmes oncogéniques et l’induction des programmes associés à la différenciation cellulaire. Pour finir, nous avons évalué le potentiel synergique anticancéreux et épigénétique de la proscillaridine A avec le médicament épigénétique la décitabine dans des lignées cancéreuses exprimants des niveaux différentiels de MYC. Dans une lignée résistante à la proscillaridine A et exprimant de faible niveau de MYC (lignée de cancer de côlon), la décitabine et la proscillaridine A démontrent des activités épigénétiques synergiques tandis que dans une lignée sensible à la proscillaridine A et surexprimant MYC (lignée de sarcome pédiatrique), la décitabine et la proscillaridine A démontrent des activités antiprolifératives synergiques. Dans ces travaux, nous avons donc démontré le potentiel de repositionner la proscillaridine A dans les cancers surexprimant MYC. Également, nous démontrons le potentiel synergique anticancéreux et épigénétique de la proscillaridine A avec la décitabine et nous suggérons d’étudier cette combinaison de médicaments dans les cancers plus résistants à la proscillaridine A. / Cardiac glycosides are sodium/potassium pomps’ inhibitors used for the treatment of heart failure, and whose anticancer and epigenetic activities have been recently characterized. However, in order to repurpose cardiac glycosides as anticancer drugs, mechanistic studies are required to identify the anticancer and epigenetic mechanism of actions. In our experiments, proscillaridin A exhibited the most powerful anticancer and epigenetic activities in colon cancer, leukemia, and sarcoma cell lines. Moreover, we demonstrated that in a panel of 14 cancer cell lines, proscillaridin A anticancer activities positively correlated with MYC protooncogene expression level. In high MYC expressing cell lines such as leukemia, proscillaridin A inhibited MYC expression through protein destabilization and through transcriptomic and translational regulation of MYC targets. Theses inhibitions are induced by the loss of lysine acetylatransferase (KAT) expressions, which are epigenetic enzymes controlling the addition of acetyl-coenzyme A on histones and other proteins such as MYC. KAT inhibitions are responsible for the global loss of histone 3 acetylation and acetylome reprogrammation in high MYC expressing cancer cells. These chromatin changes induced transcriptomic and phenotypic reprogrammation, defined by a loss of the transcription of oncogenic programs and the induction of cell differentiation. To finish, we evaluated the anticancer and epigenetic synergic potential of proscillaridin A in combination with the epigenetic drug the decitabine in cancer cell lines expressing different MYC levels. In a cancer cell line resistant to proscillaridin A treatments and expressing low MYC level (colon cancer cell line), the combination of decitabine and proscillaridin A demonstrated synergistic epigenetic activity although, in a cell line sensitive to proscillaridin A treatments and expressing high MYC level (sarcoma cell line), the combination of decitabine and proscillaridin A exhibited synergistic anti-proliferative activity. To conclude, we highlighted the potential of repurposing proscillaridin A as an anticancer treatment in high MYC expressing cells. Furthermore, we demonstrated the anticancer and epigenetic synergistic potential of proscillaridin A in combination with decitabine and we propose to study the drug combination in cancers that are resistant to proscillaridin A treatment.

Page generated in 0.064 seconds