Cachexia is a multifactorial metabolic wasting syndrome that affects a large percentage of cancer patients and results in the involuntary loss of skeletal muscle and adipose tissue. The consequences of this condition include metabolic imbalances and fatigue, which are strongly associated with poor prognosis. While the specific mechanism for skeletal muscle wasting is still undefined, LIF secreted by C26 colon carcinoma cells has recently be found to induce atrophy in treated myotubes. The purpose of this study is to determine the necessity of LIF for inducing atrophy in mouse myotubes by producing a knockout of Lif in C26 cells using CRIPSR-Cas9. Media was collected from these cells and used to treat myotubes. Measurements of myotube diameters were made and atrophy was compared between myotubes that received medium from C26 and C26Lif-/- cells. A dosage of recombinant mouse LIF was also added to LIF-deficient medium in order to determine if LIF alone was sufficient to induce atrophy. At study endpoint, myotubes that were treated with media taken from C26 cells showed significant signs of atrophy compared to myotubes that were treated C26Lif-/- media. LIF was also shown to be sufficient to induce myotube atrophy on its own, with atrophy being rescued in myotubes that received a dosage of LIF added to C26Lif-/- media. These results demonstrate that LIF is required for atrophy to be induced in mouse myotubes treated with media taken from cancer cells, and can do so independent of other secreted factors.

The study analyse presence and distribution of mutation in the LIF and IL-11 genes. The alterations were studied in peripheral blood samples by temperature gradient gel electrophoresis and sequencing.

La façon dont l'industrie pharmaceutique développe et manufacture ses produits a évolué au cours de ces dernières années. L'environnement réglementaire auquel elle est contrainte a provoqué ce changement dans le but de doter de technologies de pointe dans ses différentes activités. L’encouragement pour utiliser les technologies d’analyse de procédé (PAT) afin d’implémenter le concept de « Quality By Design » (QbD) est l’exemple le plus significatif de ce nouveau paradigme. Lentement, les industries implémentent ces technologies pour de nouveaux produits, mais également pour certains produits déjà existants, bénéficiant ainsi de leurs avantages. Pour implémenter des PAT dans un procédé, plusieurs étapes doivent être franchies, de l’étude de faisabilité des instruments jusqu’à l’approbation règlementaire. Cette thèse décrit l’étude initiale (faisabilité et développement de modèles) avant toute demande d’autorisation d’utilisation d’outils PAT (proche infra-rouge (NIR), caméra RGB et fluorescence induite par laser (LIF)) pour suivre le procédé de compression d’un mélange commercial comprenant plusieurs ingrédients. Après avoir établi le potentiel de ces différents outils, des modèles quantitatifs calculés par régression par moindres carrés partiels (PLS) ont été développés pour suivre les composants ayant une concentration aussi faible que 0,1 w/w%, avec un coefficient de détermination (R2) de 0,95. Il a également été démontré que l’utilisation conjointe de données de plus d’un outil améliorait la précision du modèle. La spécificité de chacun des outils a également été évaluée à l’aide de plan d’expériences factoriels complets pour lesquels les modèles ont été construits en faisant varier simultanément la concentration de différents éléments. Même dans ces conditions, les modèles construits ont montré une précision acceptable, en considérant les critères d’acceptation utilisés pour les produits alimentaires comme les multivitamines. Le travail présenté dans cette thèse a contribué à la publication de trois articles et de trois présentations orales. En plus de l’établissement de la preuve de concept, ce qui augmente les opportunités pour tester d’autres sondes, la possibilité de suivre en ligne la composition quantitative dans la ligne d’alimentation de la presse a également été établi. Dans ce dernier cas, tous les outils sont suffisamment précis pour suivre au moins un des composants, même si celui-ci est présent en faible concentration et fait partie d’un mélange de plusieurs composants. Conséquemment, l’industrie peut utiliser ses connaissances pour suivre le procédé de compression de façon plus adéquate en augmentant l’éventail des outils utilisés à cet effet. Une recherche fondamentale pourrait également investiguer les phénomènes tels que la ségrégation afin mieux les comprendre. / Abstract : The way pharmaceutical industry develops and manufactures their products has been changing in recent years. The regulatory environment that they are obligated to comply has been pushing this change in order to endow this activity with state of art technology. The encouragement of the use of process analytical technology (PAT) to build the quality right from the design (QbD) is perhaps the most significant example of the new paradigm. The manufacturers are implementing this technology in new and existing products and benefiting from their advantages. To implement PAT in a process, many steps must be taken (from the study of feasibility of the instruments until regulatory approval). This thesis describes the initial study (feasibility and model developments), prior to any submission of authorization, of the use of PAT tools (Near-Infrared (NIR), Red Green Blue (RGB) camera and Light Induced Fluorescence (LIF)) to monitor the compression process of a commercial multi-component blend. After the potential of these tools was assessed, quantitative Partial Least Squares (PLS) models were able to be developed to monitor components with a concentration as low as 0.1 w/w % with a R2 of 0.95. It was also proved that combining data from more than one tool was benefit for the accuracy of the model. The tools were also evaluated to their specificity by using a full factorial design where the models were built with simultaneous variations of concentration of some of the components. Even in this challenging case, the models built remained with an acceptable accuracy, considering the acceptance criteria used for dietary products such as multi-vitamins. The work developed in this thesis contributed to the publication of 3 articles and 3 communications. Along with the proof of concept that it provided - which enlarged the opportunities for testing other probes - it also proved that is possible to monitor in-line the components in the feed frame. In this latter case, all the tools were accurate enough to monitor at least one component even if they are present in low concentration and part of multi-component blends. Therefore, the industry can use this knowledge to monitor the compression process more adequately, increasing the range of tools used for the effect. Fundamental research can also be investigated as phenomena like segregation can be more accurately identified.

This work investigates the influence of one or more OH groups present on the fuel molecule and the resultant formation of NOX emissions. Combustion of oxygenated fuels has been increasing globally and such fuels offer significant potential in the reduction of pollutant emissions. One such emission class is the oxides of nitrogen, which typically form through a combination of two regimes: the thermal and non-thermal mechanisms. While thermal NO formation can be reduced by lowering the combustion temperature, non-thermal NO formation is coupled to the fuel chemistry. An experimental and computational investigation of NOX formation in three different burner configurations and under a range of equivalence ratios and temperature regimes explored the differences in NO formation. Measurements of temperature profiles and in-flame species concentrations, utilizing both probed and non-intrusive laser based techniques, allowed for the investigation of NO formation through non-thermal pathways and the differences that exist between fuels with varying numbers of OH groups. The first burner configuration was composed of a high swirl liquid spray burner with insulted combustion chamber walls designed specifically for the combustion of low energy density fuels. In this system the combustion of alcohols and glycerol (the largest by-product of biodiesel production), along with other fuels with multiple hydroxyl groups, was studied. Measurements of the mean flame temperature and exhaust gas measurements of NOX showed significant reductions in non-thermal NO concentrations with increasing numbers of OH groups. An accompanying modeling study and detailed reaction path analysis showed that fuel decomposition pathways through formaldehyde were shown a preference due to the presence of the OH groups which resulted in reduced contributions to the hydrocarbon radical pools subsequent reductions to the Prompt NO mechanism. Two burner configurations with reduced dimensionality facilitated measurements in premixed flames for temperature and species in high and low temperature flames. These measurements included probed thermocouple temperature measurements, extractive gas sampling for NO and intermediate hydrocarbon species, and planar Laser Induced Fluorescence (LIF) measurements for 2OH-LIF thermometry, semiquantitative CH2O LIF, and quantitative NO LIF. Additionally, the simplified nature of the burner geometries allowed for the modeling of the flames incorporating detailed reaction kinetics for fuel decomposition and NOX formation. Significant reductions in NO formation were observed in comparisons of alcohol and alkane flames, resulting in up to 50% reductions in the pollutant. Computational analyses and nitrogen flux accounting allowed for the identification of the reduction in NO formation through all the known NOX formation pathways. It was observed that all of the known pathways exhibited reductions in contributions to NO formation in the presence of OH functional groups, indicating a complex coupling of fuel and NOX chemistry.

The work described focuses on characterization of fluorescence dye-doped polystyrene latex particles (PSLs) dispersed in air as a candidate for advanced flow diagnostic techniques for applications in wind tunnels. PSLs with mean diameter on the order of 1 μm were provided by collaborators at NASA Langley Research Center and measurements of simultaneous Mie scattering and laser induced fluorescence (LIF) signals were obtained with the goal of providing a capability for velocity and scalar flow measurements. Three organic fluorescent dyes, Rhodamine B (RhB), Dichlorofluorescein (DCF), and Kiton Red (KR), were doped into PSLs and studied in benchtop experiments. A major interest in the present research is the application of safe dyes, thus DCF and KR are of particular interest, while RhB is used as a benchmark. The study is broken up into two major elements: response of the particles to continuous wave (CW) excitation, and response to pulsed excitation. The former was examined for mean LIF imaging and single-point single-shot measurements, the latter for planar single-shot measurements. The LIF signal has several potential uses, though the primary interest herein is the reduction of flare from wind tunnel walls which occurs at the laser excitation wavelength and the use of the fluorescence signal for sensing temperature. It is demonstrated that the LIF signal under CW excitation may be used for velocimetry with the laser-Doppler velocimetry technique, thus effective in filtering out the laser flare in the vicinity of wind tunnel models or walls. A two-band LIF technique was also demonstrated for one of the DCF batches, indicating that the technique effectively removes interfering inputs such as particle diameter and dye concentration variation. Temperature measurement uncertainties are estimated based upon the variance measured for the two-band LIF intensity ratio and the achievable dye temperature sensitivity, indicating that particles developed to date may provide about 12.5 degrees C precision. Pulsed excitation with an Nd:YAG laser at about 200mJ/pulse at 532 nm yield no fluorescence above the detection threshold of the cameras used from the DCF batch examined. However, a batch doped with Kiton Red 620 was shown to provide sufficient intensity of LIF for single-shot planar measurements such as PIV via planar LIF. The KR batch also exhibited highly non-uniform yield of fluorescence signal on a particle-to-particle basis - this despite a highly uniform Mie scattering signal. Given the uniform Mie signal and a relatively narrow Gaussian distribution of the particles size, a possible mechanism is mentioned for the LIF non-uniformity as lasing within individual particles due to whispering gallery mode resonance. / Master of Science

A espectroscopia de emissão atômica de plasma induzido por laser (LIBS, do inglês Laser Induced Breakdown Spectroscopy) é uma técnica multi-elementar que tem ganhado destaque recentemente devido à sua facilidade de uso em diversas aplicações. Entretanto, o limite de detecção da técnica é alto para alguns elementos se comparada com outras técnicas (e.g. ICP). Assim, o objetivo deste trabalho é aperfeiçoar a sensibilidade de um sistema LIBS na configuração de pulso único, através da integração com a técnica de fluorescência induzida por laser (LIF). Isso é feito por meio da inserção de um laser com um comprimento de onda em uma transição ressonante do elemento cuja intensidade de emissão deseja-se ter elevada, visando a redução dos efeitos de matriz das amostras. Para este fim, foram desenvolvidos um laser de diodo contínuo de cavidade estendida e sua eletrônica de controle, almejando um sistema robusto, estável em frequência, com baixo ruído espectral e resistente a estresses mecânicos, elétricos e térmicos. Os mesmos foram integrados a um sistema LIBS para ser feita a comprovação da eficiência da técnica LIBS-LIF. / The laser-induced breakdown plasma spectroscopy (LIBS) is a multi-elemental technique that has been gainning prominence recently due to its easy usability in various applications. However, the limit of detection of this technique is high for some elements compared to other techniques (e.g. ICP). Thus, the objective of this work is to improve the sensitivity of LIBS on the single pulse configuration, through integration with the laser-induced fluorescence (LIF) technique. This is done adding a laser with a wavelength in a resonant transition of the element whose emission intensity needs to be improved, focusing on reducing the matrix effects of samples. To achieve this purpose, a continuous external cavity diode laser was developed and its control driver, aiming to create a robust system, stable in frequency, with low spectral noise and resistant to adverse mechanical, electrical and thermal stresses. Both were integrated with a LIBS system for the evaluation of the LIBS-LIF technique efficiency.

Une des pistes majeures pour obtenir des turbines à gaz moins polluantes est l'utilisation de chambres de combustion fonctionnant en régime prémélangé pauvre. Cependant, dans de tels régimes de fonctionnement, la flamme obtenue est cependant plus facilement sujette aux instabilités thermo-acoustiques.Dans cette thèse, un brûleur étagé swirlé fonctionnant au propane a été employé pour illustrer une méthode d'analyse de la combustion prémélangée. Cette installation a été étudiée à l'aide de diagnostics classiques (micros, PLIF, film à haute cadence de la flamme).La stratégie de post-traitement développée dans cette thèse utilise par contre des outils eux aussi classiques (PSD, moyenne de phase) mais aussi une méthode d'analyse avancée, la Décomposition en Modes Dynamiques. Celle-ci est notamment étudiée em détail afin d'en cerner les avantages et les limitations dans le cadre de l'analye des instabilités de combustion. / One of the major ways of reducing pollutant emissions in gas turbines is using combustion chambers with lean premixed mixtures. However, in such operating conditions the flame is more susceptible to thermo-acoustic instabilities. In the present work, a propane-fed swirled burner using two injection stages is used to illustrate a post-processing strategy for premixed combustion analysis. This model burner has been studied using classic diagnostics (microphones, PLIF, highspeed imaging).The strategy developed in the present work uses both classic postprocessing tools (PSD, phase averaging) and an advanced method, the Dynamic Mode Decomposition. In particular, this method is studied in detail and compared to more lassic ones in order to clearly point its advantages as well as its shortcomings when used to study combustion instabilities.

La décharge contrôlée par barrière diélectrique est un type de décharge hors-équilibre, fonctionnant à la pression atmosphérique. Normalement, elle est générée en état filamentaire qui se caractérise par une multitude de micro-décharges. Par contre, dans certaines conditions, nous pouvons obtenir une décharge homogène. Par exemple, dans notre étude, une décharge homogène est obtenue en atmosphère principale d’azote à la pression atmosphérique et comme ses caractéristiques électriques sont similaires à celles d’une décharge sombre de Townsend à basse pression, elle est appelée décharge de Townsend à la pression atmosphérique (DTPA). Pour maintenir un claquage de Townsend, un effet mémoire entre deux décharges est nécessaire. Cet effet mémoire conduit à la création d’électrons germes sous faible champ qui, lors de l’inversion de polarité permettent l’obtention d’une décharge homogène. Un marqueur de cet effet mémoire observable par les caractéristiques électriques de la décharge est le saut de courant quand la tension du gaz passe par zéro: plus le saut de courant est grand, plus l’effet mémoire est important. Des études précédentes ont montré l’importance des métastables de l’azote N2(A), qui produisent des électrons par émission secondaire entre deux décharges lors du bombardement des surfaces diélectriques. Néanmoins, nous observons que l’ajout d’une faible quantité de gaz oxydant (ici de l’oxygène) permet d’obtenir une décharge homogène plus stable, malgré la destruction considérable de N2(A) par quenching par des espèces oxydantes. En conséquence, nous proposons un autre processus pour la production des électrons germes en volume, basé sur la réaction d’ionisation associative suivante: N(2P)+O(3P) -->NO++e- où N(2P) est créé par la réaction: N(4S)+N2(A)-->N(2P)+N2(X). Pour vérifier cette hypothèse, nous utilisons la technique de la fluorescence induite par laser (LIF/TALIF), afin de déterminer les densités absolues de N(4S), O(3P) et NO. Les mesures sont faites pour différentes conditions expérimentales pour étudier l’influence du flux de gaz, de la puissance de la décharge et tout particulièrement de la concentration d’oxygène. Avec une augmentation de la concentration en oxygène jusqu’à 200ppm, la densité de N(4S) diminue à cause de sa destruction par les espèces oxydantes. Les densités de O(3P) et NO(X) augmentent puis saturent. Ceci peut être expliqué par le fait que la production de O(3P) et NO(X) est liée à la densité de N2(A). Ainsi pour de faibles concentrations en oxygène, l’ajout d’oxygène favorise la production de O(3P) et NO(X), mais pour des concentrations plus fortes, la destruction de N2(A) par quenching par les espèces oxydantes devient plus importante, limitant ainsi la production de O(3P) et NO(X). Avec les densités de N(4S), O(3P) et NO(X) mesurées expérimentalement, et la densité de N2(A) déterminée par Dilecce et al, la densité de N(2P) entre deux décharges peut être estimée par un modèle simple. Il est alors possible d’estimer la production d’électrons germes par les réactions d’ionisation associative et finalement le saut de courant qui en résulte. Un bon accord est observé entre les évolutions du saut de courant mesuré et calculé, même si des écarts quantitatifs subsistent. En conclusion, l’ionisation associative peut être considérée comme une bonne candidate pour expliquer l’augmentation de la création d’électrons germe entre deux décharges lorsqu’une faible quantité d’oxygène est introduite dans l’azote. / Dielectric barrier discharge is a type of non-equilibrium discharge, operating at atmospheric pressure. Normally, it is generated in filamentary mode which is characterized by a multitude of micro-discharges. Nevertheless, under certain conditions, it is possible to obtain a homogeneous discharge. In our study, the discharge is ignited in a nitrogen based atmosphere at atmospheric pressure and since its electrical characteristics are similar to that of a Townsend discharge at low pressure, it is called atmospheric pressure Townsend discharge (APTD). To maintain a Townsend discharge, a memory effect between two successive discharges is necessary. This memory effect is characterized by the creation of seed electrons under low electric field. A marker of this memory effect can be observed on the electrical characteristics: a current jump is observed when the gas voltage polarity reverses. The larger the current jump, the more important the memory effect. Previous investigations showed the importance of the N2(A) metastable molecules, which produce electrons by secondary emission on the dielectrics. Nevertheless, we observe that the addition of a small amount of oxidizing gas (in this case oxygen) results in a more stable homogeneous discharge, despite the considerable destruction of N2(A) by quenching by the oxidizing species. Therefore, we propose another process for the production of seed electrons, based on the following associative ionization reaction: N(2P)+O(3P)-->NO++e- where N(2P) is created by: N(4S)+N2(A)-->N(2P)+N2(X). To verify this hypothesis, laser-induced fluorescence (LIF/TALIF) measurements were done to determine the absolute densities of N(4S), O(3P) and NO(X) between two discharges. The measurements were performed under different experimental conditions to study the influence of the gas flow, the discharge power and more specifically the concentration of oxygen. For increasing oxygen concentration up to 200ppm, the density of N(4S) decreases because of its higher destruction by the oxidizing species. The densities of O(3P) and NO(X) increase and then become nearly constant. It can be explained by the fact that the production mechanisms of O(3P) and NO(X) involve N2(A) molecules. Then, whereas the addition of a small amount of oxygen favors the production of O(3P) and NO(X), a higher oxygen concentration induces a larger destruction of N2(A) by quenching due to the oxidizing species, which finally limits the production of O(3P) and NO(X). Knowing the densities of N(4S), O(3P) and NO(X) from experimental measurements, and the density of N2(A) from the work of Dilecce et al, the density of N(2P) can be estimated using a simple model, as well as the production of electrons due to associative ionizations. Finally the current jump can be calculated. The evolutions of the measured and calculated current jump have the same tendency even if the calculated values are much higher. In conclusion, associative ionization can be considered as a serious candidate to explain the increase of the memory effect and discharge stability when a small amount of oxygen is added to the nitrogen atmosphere of an APTD.

Les carcinomes évoluent dans un microenvironnement inflammatoire composé de cellules stromales (fibroblastes, cellules endothéliales et immunitaires) immergées dans une matrice extracellulaire (MEC). Les fibroblastes associés aux carcinomes (FACs) déposent et remodèlent la MEC dans le but de la rendre permissive à la croissance et l’invasion tumorale. Parmi les facteurs pro-inflammatoires responsables de l’activation des fibroblastes résidents, la cytokine Leukemia Inhibitory Factor (LIF) détient un rôle capital. En régulant l’activité de la chaîne légère de la myosine II (MLC-II), LIF induit la contractilité du cytosquelette d’actomyosine, générant des forces de tension et le remodelage de la MEC par les FACs. En revanche, les gènes régulés par LIF impliqués dans le phénotype pro-invasif des FACs ne sont pas connus. A l’aide d’un criblage phénotypique en trois dimensions, nous avons identifiés ICAM-1 comme régulateur majeur du remodelage de la MEC par les FACs. Nous démontrons qu’ICAM-1 est nécessaire et suffisant pour induire la réorganisation de la MEC indispensable à l’invasion collective des cellules de carcinome squameux. En effet, ICAM-1 est un régulateur de la contractilité cellulaire dépendante de la voie de signalisation RhoA-ROCK et de la kinase Src. De plus, la contractilité cellulaire régule l’expression d’ICAM-1, menant ainsi à une boucle de régulation positive. Nous proposons alors qu’ICAM-1 représente une cible thérapeutique afin de lutter contre l’invasion tumorale et la dissémination métastatique. / Acto-myosin contractility in carcinoma-associated fibroblasts leads to the assembly of the tumor extracellular matrix. The pro-inflammatory cytokine LIF governs fibroblast activation in cancer by regulating the myosin light chain 2 activity. So far, however, how LIF mediates cytoskeleton contractility remains unknown. Using phenotypic screening assays based on knock down of LIF-dependent genes in fibroblasts, we identified ICAM1 as a crucial regulator of stroma fibroblast proinvasive matrix remodeling. We demonstrate that ICAM1 is necessary and sufficient to promote inflammation-dependent extracellular matrix organization, which leads to cancer cell invasion. Indeed, ICAM1 mediates generation of acto-myosin contractility downstream of the Src kinases in stromal fibroblasts. Moreover, acto-myosin contractility regulates ICAM1 expression, establishing a positive feedback signaling. Thus, targeting stromal ICAM1 might constitute a possible therapeutic mean to counteract tumor cell invasion and dissemination.

Cette thèse s'intéresse à l'écoulement convectif induit par une paroi chauffante isotherme. La couche limite turbulente qui s'établit le long de celle-ci s'apparente à un panache, bien que les conditions de paroi en modifient significativement certaines caractéristiques typiques. Dans l'étude présentée, l'environnement est un milieu clos. Puisque le fluide de moindre densité s'accumule dans la partie haute de l'enceinte, une stratification en température s'établit. Afin de mieux comprendre les mécanismes qui entrent en jeu dans ce type de panache et son interaction avec le fluide ambiant, nous déployons une approche à la fois expérimentale et théorique. Sur le plan expérimental, une technique combinant Velocimétrie par Images de Particules (PIV) et Fluorescence Induite par Laser (LIF) est mise au point, et permet d'acquérir simultanément la vitesse et la température du fluide dans un plan de mesure qui couvre l'ensemble de l'écoulement. Sur le plan théorique, un modèle numérique mono-dimensionnel est développé. Il est basé sur la théorie d'entraînement de Morton et al (1956) pour la partie turbulente du panache, et tient compte de son caractère laminaire initial grâce à des solutions de similarité. Les comparaisons détaillées entre ce modèle et les résultats expérimentaux montrent les limites des modèles classiques et la pertinence des améliorations introduites. Nous évaluons notamment la contribution de la portion laminaire, et mettons en évidence le fait que le coefficient d'entraînement varie en fonction de la stratification ambiante. / This thesis focuses on the convective flow induced by a heated isotherm wall. A turbulent boundary layer develops along this wall, and resembles to a plume unlike its typical characterics are significantly modified by the boundary condition at the wall. In this study the environment is a closed box in which the lighter fluid continuously accumulates in the upper part, thus producing a temperature stratification in the interior. In order to better understand the dynamics of such a plume as well as its interaction with the ambient fluid, we deploy an approach that is both experimental and theoretical. Concerning the experiments, we developed a technique which combines Particle Image Velocimetry (PIV) with Laser Induced Fluorescence (LIF). This technique allows to simultaneously acquire the velocity and the temperature of the fluid in a plane which covers the entire flow. As concerning the theory, a one-dimensional numerical model is developed. It is based on the entrainment theory by Morton et al (1956) as for the turbulent part of the plume, and it takes into account the initial laminar character of the plume thanks to similarity solutions. The detailed comparisons between this model and the experimental results show the limits of the classical models and the relevance of the introduced improvements. In particular we evaluate the contribution of the laminar part and we highlight that the entrainment coefficient varies as a function of the ambient stratification.