This thesis presents the development of a novel, targeted, lipid-based, microbubble ultrasound contrast agent (UCA) for assessment of coronary heart disease (CHD) with high frequency intravascular ultrasound (IVUS). The targeting mechanisms assessed for microbubble attachment include a streptavidin-biotin mechanism, electrostatic mechanism and antibody targeting. The microbubble has been optimized for use with 40MHz IVUS through an investigation into the effect of various production methods on the echogenicity of the agent. Echogenicity has been assessed from quantification of the RF data and determination of the mean ultrasound backscatter. Agitation was found to be the optimal method of production resulting in a 3.94(±1.14)dB increase in the mean backscatter. The stability of the agent has also been assessed over time and optimal storage of the agent determined. A novel flow chamber has been developed for assessment of microbubble detachment under very high WSS. The flow chamber has been calibrated to 50Pa wall shear stress (WSS) using laser Doppler anemometry (LDA). Higher WSS was achieved through the use of higher viscosity fluids. The streptavidin-biotin bond has been assessed within the flow chamber and was found to be 75 times stronger than an electrostatic control. Antibody attachment to the microbubbles via a streptavidin-biotin bridge has been optimised with 91.20(±0.02)% of the microbubbles having antibodies attached. A flow system has also been developed for assessment of microbubble attachment to cells under very low WSS. Microbubbles have been successfully targeted to SK-Hep-1 cells using acoustic radiation force. In addition attachment of the microbubbles to SK-Hep-1 cells has been observed under 0.03Pa WSS in the Ibidi μ-slides.

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Thesis (Ph. D.)--University of Hong Kong, 2007. / Also available online.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

Thesis (Ph. D.)--Biomedical Engineering, Georgia Institute of Technology, 2007. / Committee Chair: Nie, Shuming; Committee Member: Lyon, L. Andrew; Committee Member: McIntire, Larry V.; Committee Member: Murthy, Niren; Committee Member: Prausnitz, Mark R.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 187-217) Also available in print.

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Cette thèse regroupe un ensemble de quatre articles analysant la conduite de la politique monétaire dans les économies émergentes qui ont adopté un régime de ciblage d'inflation. La première partie de ce travail est basée sur une approche positive, qui s'appuie sur l'expérience des 19 économies qui se sont dotées de ce cadre institutionnel. Nous examinons quel régime de change ces économies ont choisi, ainsi que les déterminants de leur choix. Ainsi, un premier chapitre propose une nouvelle méthode de classification des régimes de change par l'estimation de mixtures de Gaussienne, alors qu'un second chapitre privilégie l'économétrie de panel pour analyser les déterminants des régimes observés. Puis, dans une démarche normative, nous analysons dans la seconde partie de cette thèse comment définir la politique monétaire optimale. Notre approche s'appuie alors sur la modélisation d'équilibre général dynamique et stochastique. Nous étudions quelle politique doit être menée par les autorités monétaires d'économies émergentes confrontées à des chocs sur le prix des matières premières et alimentaires, et à des inégalités d'accès au crédit. / This PhD dissertation is made of four papers on central banking in inflation-targeting emerging economies. The first part of the dissertation is dedicated to two empirical works, based on the experiences of the 19 emerging economies that have adopted an inflation-targeting framework. I examine what exchange rate arrangement these economies are implementing together with the inflation targeting strategy, and what can explain their choice. ln the first chapter, I propose a new method to build up taxonomies of exchange-rate regimes. My approach is based on Gaussian mixture estimates. ln the second chapter, the choices for exchange-rate arrangements are explained though panel econometrics analysis. The second part of the dissertation is about the theory of optimal monetary policy. ln the first chapter, I propose an original dynamic stochastic general equilibrium model to study what should monetary policy do when food price hikes, in a small open emerging economy. ln the last chapter, a similar modeling approach is used to analysis how credit constraints impact monetary policy in financially venerable emerging economies.