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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.
61

Copolymérisation plasma : étude des mécanismes de croissance et de la structuration des couches minces copolymères

Chahine, Claudine 24 January 2013 (has links) (PDF)
Le travail présenté dans ce mémoire consiste à élaborer en une seule étape une couche mince organique ayant les propriétés chimiques et/ou morphologiques souhaitées. Cette démarche vise à copolymériser par voie plasma (PECVD) deux monomères antagonistes (apolaire et polaire) afin de contrôler la répartition et la taille des nodules de l'un des polymères dispersé dans l'autre phase et d'obtenir ainsi une structuration chimique et/ou morphologique. Pour ce faire, six précurseurs ont été sélectionnés de façon à couvrir une large gamme de polarité: l'alcool allylique (AA), l'acide acrylique (AAc), l'aniline (ANi), le diéthylèneglycol diméthyl éther (DEGDME), le 1H,1H,2H-perfluoro-1-décène (HDFD) et le 2-(diméthylamino) éthyle méthacrylate (DMAEMA).La première partie de ce travail est centrée sur l'étude des mécanismes de croissance des différents homopolymères par voie plasma pulsé. Les cinétiques de dépôt, les structures chimiques et les morphologies sont plus spécifiquement détaillées pour deux monomères, les HDFD et DMAEMA en fonction des paramètres du procédé plasma, la polymérisation plasma de ces deux précurseurs étant pour la première fois décrite. La caractérisation des couches minces obtenues repose sur la spectroscopie Infrarouge à Transformée de Fourier (FTIR), la spectroscopie de photoélectrons X (XPS) et la microscopie à force atomique (AFM). Cette étude a montré le rôle catalytique des groupements fluorés induisant des vitesses de dépôt plus conséquentes. Même si la croissance est prépondérante durant le temps de décharge, le dépôt est non négligeable pendant la post-décharge. La structure chimique des polymères plasma est fortement dépendante des paramètres de la décharge et notamment la puissance et le temps de décharge. La spectroscopie FTIR s'est révélée comme un outil performant pour l'évaluation de la rétention de la structure chimique de l'entité monomère initiale dans le polymère plasma. Ces homopolymères présentent une morphologie homogène sans rugosité.Dans la deuxième partie, nous abordons la copolymérisation plasma pulsé. Les différents copolymères synthétisés sont p-AA-co-HDFD, p-AAc-co-HDFD, p-ANi-co-HDFD, p-DEGDME-co-HDFD, p-DMAEMA-co-HDFD, p-DMAEMA-co-ANi. La plupart sont issus de comonomères hydrophiles et hydrophobes à l'exception d'un synthétisé à partir de deux précurseurs polaires. Les cinétiques de dépôt, les propriétés chimiques et morphologiques sont discutées en fonction des paramètres plasma tels que la puissance injectée mais aussi des proportions relatives des différents comonomères. Les différentes analyses chimiques entreprises montrent plutôt la formation d'un mélange d'homopolymères ou d'un copolymère à bloc plutôt que la croissance d'un nouveau matériau. Cette hypothèse est étayée par la mise en évidence d'une structuration morphologique correspondant à la présence d'îlots à la surface.
62

A Src-Abl kinase inhibitor, SKI-606, blocks breast cancer invasion, growth and metastasis in vitro and in vivo /

Jallal, Houda. January 2007 (has links)
The central role of Src in the development of several malignancies including breast cancer and the accumulating evidence of its interaction with receptor tyrosine kinases (RTK), integrins and steroid receptors have identified it as an attractive therapeutic target. In the current study we have evaluated the effect of a Src/Abl kinase inhibitor SKI-606, on breast cancer growth, migration, invasion and metastasis. Treatment of human breast cancer cells MDA-MB-231 with SKI-606 caused a marked inhibition of cell proliferation, invasion and migration by inhibiting MAPK and Akt phosphorylation. For in vivo studies MDA-MB-231 cells transfected with the plasmid encoding green fluorescent protein (GFP) [MDA-MB-231-GFP] were inoculated into mammary fat pad of female BALB/c nu/nu mice. Once tumor volume reached 30-50 mm3, animals were randomized and treated with vehicle alone or 150 mg/kg of SKI-606 by daily oral gavage. Experimental animals receiving SKI-606 developed tumors of significantly smaller volume (45-54%) as compared to control animals receiving vehicle alone. Analysis of lungs, liver and spleen of these animals showed a significant decrease in GFP positive tumor metastasis in animals receiving SKI-606 at a dose that was well tolerated. Western blot analysis and immunohistochemical analysis of primary tumors showed that these effects were due to the ability of SKI-606 to block tumor cell proliferation, angiogenesis, growth factors expression and inhibition of Src mediated signalling pathways in vivo. Together the results from these studies provide compelling evidence for the use of Src inhibitors as therapeutic agents for blocking breast cancer growth and metastasis.
63

Propriedades ópticas não-lineares de oligômeros de anilina / Nonlinear optical properties of aniline oligomers

Paulo Licênio Franzen 29 October 2002 (has links)
Apresentamos os resultados do estudo das não-linearidades ópticas de origem eletrônica de duas moléculas da classe dos oligômeros de anilina: o dímero e o tetrâmero. Foram medidas quatro concentrações de tetrâmero, puras e também dopadas em 33 e 100%; uma de dímero pura e outra dopada em 100%. As soluções foram preparadas usando dimetil-sulfóxido (DMSO) como solvente e a dopagem foi realizada com ácido clorídrico. As amostras foram caracterizadas por medidas de absorção linear e fluorescência antes das medidas não-lineares. Obtivemos os valores da primeira hiperpolarizabilidade (?) para todas as amostras, o índice de refração não-linear (n2) do tetrâmero dopado e não dopado, e a absorção não-linear em função da intensidade e da concentração do tetrâmero. As medidas foram realizadas através das técnicas de Varredura-Z, absorção não-linear e espalhamento Hiper-Rayleigh. Os resultados foram interpretados em termos da comparação entre diferentes estados de dopagem e da variação da seção de choque do estado fundamental para o primeiro excitado. / We report on the study of electronic optical non linearities in two aniline oligomers: dimer and the tetramer. Four tetramer concentrations were measured, pure and also 33 and 100% doped; one of dimer non doped another 100% doped. The solutions were prepared using dimethyl sulfoxide (DMSO) as solvent and the doping was performed with hydrochloric acid. The samples were characterized by measurements of linear absorption and fluorescence. We obtained the values of the first hyperpolarizability (?) for all samples, the non linear index of refraction (n2) for non doped and doped tetramer, and the non linear absorption in function of intensity and concentration of the tetramer. The measurements were accomplished through the techniques of Z-Scan, non linear absorption and Hyper-Rayleigh Scattering. The results were interpreted in terms of the comparison among different doping states and of the variation of cross-section for the transition from ground to the first excited states.
64

Synthese von N-Benzhydryl-anilinen und Untersuchungen zu Struktur-Eigenschafts-Zusammenhaengen hinsichtlich der Photoleitung in Polymermatrizen

Mais, Silvio 01 August 1995 (has links)
Bibliographische Beschreibung und Referat Mais, Silvio Synthese von N-Benzhydryl-anilinen und Untersuchungen zu Struktur- Eigenschafts-Zusammenhaengen hinsichtlich der Photoleitung in Polymermatrizen Technische Universitaet Chemnitz-Zwickau, Fakultaet fuer Naturwissenschaften, Dissertation, 1995, 134 Seiten Es erfolgen zum gegenwaertigen Kenntnisstand der Elektrophotographie kurze Abrisse bezueglich Wirkungsweise, Messprinzipien, Theorie der Photoleitfaehigkeit und Struktur-Eigenschafts-Zusammenhaengen. Synthesen von N-Benzhydryl-anilinen und substituierten N,N'-Dibenzhydryl-4,4'-diamino-biphenyle werden vorgestellt und diskutiert. Im Mittelpunkt steht die Substituentenvariation von Akzeptoren bis Donatoren. Vergleichende elektrophotographische Empfindlichkeitsmessungen dieser Verbindungen in polymeren Bindemittelschichten zeigen eine Abhaengigkeit der Photoleitung von der Substitution, welche sich mit den entsprechenden Hammett- Konstanten beschreiben laesst. NMR-Untersuchungen belegen die Abhaengigkeiten der chemischen Verschiebungen und Kopplungskonstanten bestimmter 1H-, 13C- und 15N-Kerne von der Substituentenvariation, welche sich ebenfalls mit grosser Korrelationsguete durch Hammett- oder Taft-Konstanten linear beschreiben lassen. Die elektrophotographische Empfindlichkeit der untersuchten Schichtsysteme laesst sich durch Farbstoffsensibilisierung und Erhoehung der Photoleiterkonzentration in praktisch interessierender Groessenordnungen steigern.
65

Salicylic Acid-Catalyzed Radical Arylations from In-situ Formed Arenediazonium Salts

Felipe-Blanco, Diego 22 July 2020 (has links)
In this thesis, it has been studied the deamination of aromatic amines, through in situ formed diazonium salts as reaction intermediates, catalyzed by salicylic acid, a nontoxic, eco-friendly and economic catalyst. In the early part of the thesis (Chapter I) it has studied the deamination process using THF as solvent as hydrogen donor and anilines as radical source, to carry the hydrodeamination reaction, as well as the process in its deuterodeamination manner using deuterated solvent. Following with this study in Chapter II and Chapter III, it has been studied the addition of the aromatic radicals, generated with the methodology employed in the first chapter, to different types of double bond, to form α-arylketones (Chapter II) and γ-aryl lactones, throw a following intramolecular cyclization (Chapter III). Finally, in Chapter IV was studied the construction of arylphosphonates, starting from anilines as radical source, and triphenylphosphite, and in this case specially, mechanism was hard explored. In every work, the methodologies could be scaled-up above 1 g, reaction mechanisms were proposed and studied through control and mechanistical experiments, and follow reactions were carried out.
66

A Src-Abl kinase inhibitor, SKI-606, blocks breast cancer invasion, growth and metastasis in vitro and in vivo /

Jallal, Houda. January 2007 (has links)
No description available.

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