The overall goal of this work was to develop and utilize microfluidic models for investigating bacterial chemotaxis and biofilm formation - phenotypes that play key roles in bacterial infections. Classical methods for investigating chemotaxis and biofilm formation have many limitations and drawbacks. These include being unsuitable for investigating the effect of chemorepellents, non-quantitative readouts, and not accounting for interaction between hydrodynamics and biofilm formation. The novel microfluidic model systems for chemotaxis and biofilm formation developed in this study addresses these drawbacks. Chemotaxis model system development was done in three stages. We first developed two static chemotaxis model systems - the two fluorophore chemotaxis agarose plug assay and the mu Plug assay - for rapidly determining the extent of chemotaxis in a qualitative manner. A key feature of these model systems was the incorporation of dead cells and differential labeling with green and red fluorescent proteins for partitioning the effects of movement due to fluid flow from chemotaxis. The static systems were used to rapidly screen a wide range of conditions for use in the flow-based mu Flow chemotaxis model system. The effect of four major variables - cell preparation method, gradient strength, flow rate in the device, and imaging position - that influence the chemotactic response in the mu Flow was characterized using the repellent taxis from Ni^2 gradients as the model chemoeffector. Using the mu Flow chemotaxis device, we investigated the chemotaxis of Escherichia coli RP437 to different signals that are present in the human gastrointestinal tract and are likely to be mediators of infection through their effect on chemotaxis. Our data show that the bacterial signal indole is a repellent, while the signals autoinducer-2 (AI-2) and isatin are attractants for E. coli RP437. However, cells exposed to a competing gradient of indole and either AI-2 or isatin, attracts E. coli. The ?Flow device was also used to refute a long-standing view on how the repellent Ni2 is sensed in E. coli. Our data show that only the Tar chemoreceptor is needed for sensing Ni^2 and the nickel binding protein, NikA, and the Ni^2 transport system proteins, NikB and NikC, are not required for repellent taxis from nickel. A microfluidic biofilm model was also developed in this study and used in conjunction with a mathematical model to investigate biofilm formation and quorum sensing in closed systems (where biofilm growth and hydrodynamics are interdependent). The mathematical model predictions were experimentally validated using Pseudomonas aeruginosa PA14 in a microfluidic biofilm system at various flow rates.

A series of nickel(II) and Pt(II) complexes supported by the bis(2-diphenylphosphinophenyl)amide ligand, [PNP]¢w have been prepared. In Nickel(II) chemistry, the halide complexes are both air and water stable. The nickel(II) alkyl and aryl derivatives were presented including those in which the alkyl contains

­^¤åºK­n Chapter 1 A new chelating N,N ligand family incorporating an anilido-phosphinimine donor set has been designed. The ligand1-(NHAr)-2-(PPh2=NAr¡¦)C6H4(iPr[NN]DippH: Ar = 2,6-iPr2-C6H3, Ar¡¦ = 2,6-iPr2-C6H3; iPr [NN]MesH: Ar = 2,6-iPr2-C6H3, Ar¡¦ = 2, 4, 6-Me3C6H2; Me[NN]MesH: 2,6-Me2-C6H3, Ar¡¦ = 2, 4, 6-Me3C6H2) were synthesized via a route of reacting amido phosphine ligands with aryl azides. We observed different behaviors of adding n-BuLi in different solvents. In 31P NMR, we found the changed of chemical shift upon the different Ar¡¦ substituents. When substituent on Nphosphinimine was Dipp, there are larger chemical shift change. Addition of [NN]H to ZnMe2 or ZnEt2 in toluene or Et2O at -35oC generated the monomeric, three-coodinate [NN]ZnR (R = Me, Et)(schem 1), while the metathesis reaction of Zn(OAc)2 with iPr[NN]DippLi(Et2O) in THF at -35oC produced iPr[NN]DippZnOAc. But in the same condition, we made the iPr[NP] iPrLi(DME) produced homoleptic {iPr[NP] iPr}2Zn. All of the complexes were characterized by multinuclear NMR spectroscopy or X-ray crystallography. We used [NN]ZnR catalyzed ring-opening polymerization of £`-Caprolactone . The results of catalysis had good yields in 90 to 100% and narrow PDI around 1.5. But they are not a living polymerization catalysis. Chapter 2 We use {[NP]NiCl}2 catalyzed Kumada reactions of alkyl halide or aryl halide with Grignard reagent. In the result, Used {iPr[NP]iPr}2NiCl catalyzed aryl halide with Grignard reagent is better than other {[NP]}2NiCl, but not good catalyzed alkyl halide with Grignard reagent. We do kinetic studies of benzene C-H bond activation by nickel complexes of amido phosphine ligand. By the result, We can defind the benzene C-H bond activation was association rection.

Reproduction de : Thèse de doctorat : Toxicologie : Metz : 1978. / Titre provenant de l'écran-titre. Notes bibliographiques. Index.

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on Jan. 21, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.

Thesis (M.S. in M.S.E.)--School of Materials Science and Engineering, Georgia Institute of Technology, 2004. Directed by W. Steven Johnson. / Includes bibliographical references (leaves 141-148).

Thesis (Ph. D.)--Lehigh University, 2001. / Includes vita. Includes bibliographical references (leaves 212-218).

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 2002. / Thesis advisor(s): Terry R. McNelley. Includes bibliographical references (p. 53-55). Also available online.

Thesis (Ph. D.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 116-125).

Thesis (Ph. D.)--Lehigh University, 2003. / Includes vita. Includes bibliographical references (leaves 100-104).