Thesis (Ph.D.). / Written for the Dept. of Biomedical Engineering. Title from title page of PDF (viewed 2009/06/18). Includes bibliographical references.

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 156-165). Also available in electronic version. Access restricted to campus users.

Thesis (M.S.)--University of Michigan, 1988.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2006. / Steven Danyluk, Committee Chair ; David Sanborn, Committee Member ; Shreyes Melkote, Committee Member. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 11, 2006) Includes bibliographical references.

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2006. / Steven Danyluk, Committee Chair ; Thomas Kurfess, Committee Member ; Peter Hesketh, Committee Member ; Jiri Janata, Committee Member ; Ajeet Rohatgi, Committee Member.

Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2006. / Fahrni, Christoph, Committee Chair ; Doyle, Donald, Committee Member ; Wilkinson, Angus, Committee Member ; Zhang, Z. John, Committee Member ; Radhakrishna, Harish, Committee Member.

Thesis (M.Sc.Eng.) / The use of implantable neural probes has become common, both for stimulation and recording, and their applications range from chronic pain treatment to implementation of brain machine interfaces (BMI). Studies have shown that signal quality of implanted electrodes decays over time mainly due to the immune response. Characterization of the tissue-electrode interface is critical for better understanding of the physiological dynamics and potential performance improvement of the electrode itself and its task. This work describes the fabrication of an implantable electrode with optical measurement capabilities for providing means to characterize the tissue-electrode interface using optical spectroscopy. The electrode has a set of waveguides embedded in its shanks, which are used to inject white light into tissue and then collect the light reflected from the tissue surrounding the shanks. The collected light was analyzed with a spectrometer and the spectra processed to detect changes in optical properties, information that allows to track physiological changes. It is believed that the immune response can be correlated to changes in scattering as more cells are recruited to the injury site. The increased cell density in local injury/implantation sites increases the amount of scattering due to the increased number of cell nuclei and membranes that light encounters in its path. Investigation of scattering and absorption coefficients in such interface and their change over time can provide useful data for modeling and determining physiological parameters like blood oxygenation while the actual shape of the acquired spectra might highlight particular phenomena that can be indicative of scaring process or hemorrhaging. Validation of this system was done using optical phantoms based on polystyrene spheres and solutions with various concentrations of fat emulsion, which yielded scattering coefficients similar to those of brain tissue. Results suggest that the developed optrodes are able to detect differences between samples with different scattering coefficients. Improvements of fabrication process are discussed based on experimental results and future work includes attempting to perform fluorescence measurements of voltage reporters for optogenetic applications. The ultimate goal of this project was to create a novel device that is capable of satisfying the unmet need of tissue characterization at the implanted electrode interface as well as a tool for the optogenetics field suitable for greater depths than those a microscope can achieve.

Several methods have been used for the characterisation of minerals in powders and in rocks. Particular emphasis has been directed towards the use of chemical probes to elucidate the surface mineralogy in order to provide detection profiles suitable for both qualitative and quantitative chemometric analysis. The first probe evaluated was cyclohexylamine (CHA). Ni[2+]- and Al[2+]-exchanged montmorillonite (SWy-2 -Wyoming, USA), were exposed to cyclohexylamine vapour (CHA). The samples were characterised by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and evolved gas analysis (EGA), which included TGA, real time gas phase FTIR (RT-GP-FTIR), real time mass spectrometry (RT-MS) and organic trap module-gas chromatography-mass spectrometry (OTM-GC-MS). CHA decomposed along different routes via interrelated mechanisms that were cation dependent. Over Al[3+]-SWy-2 hydrodenitrogenation via the Hofmann degradation was the predominant route whereas ring dehydrogenation to aniline either directly from CHA or possibly via cyclohexylimine was significant over Ni[2+]-SWy-2. Very little unmodified cyclohexylamine was detected in the evolved gases which means that the desorption of CHA cannot be used as a quantitative measure of the acidity of cation-exchanged clays. Nonetheless, as a qualitative probe, CHA has the potential to distinguish the difference between Ni[2+] and Al[3+]-SWy-2.The second probe evaluated was 3-cyanopyridine (3CYP). TGA has shown that temperature programmed desorption (TPD) of 3CYP is capable of distinguishing between the Ni[2+]- and Al[3+] exchanged forms of SWy-2. 3CYP was found to be unsuitable for a variety of reasons highlighted by its ability to condense within the EGA system and the long incubation times necessary to produce detectable thermal events. The most suitable probe used so far is Dimethylformamide (DMF), being able to intercalate quickly and showing no evidence of modification. Principal component analysis (PCA) and partial least squares (PLS) modelling techniques were applied to the EGA DMF detection profiles of four clay mineral groups. Each group was successfully characterised and provided valuable information about intra and inter group relationships. The use of RT-MS detection profiles for ions m/z =18 and 73 (DMF parent ion) were shown to have the most potential for more sensitive quantitative applications. Application of quantitative PLS modelling to mixed mineral standards has shown that it is possible to estimate the clay mineral constituents in both powders and rocks. The use of the ion m/z = 73 provided an R[2] value of 0.98. Use of ion m/z =18 (H[2]O) has perhaps shown most potential, due to its ability to produce training sets with excellent correlation coefficients of 0.95 for SWy-2, 0.97 for KGa-2 and 0.95 for CCa-1. However, because SWy-2 and 1-Mt (illite) demonstrate overlapping detection of DMF (where uptake of DMF by 1-Mt is comparatively small), it is impossible to directly separate their relative contributions at the concentration levels under study. The use of mass spectrometry has shown that it is possible to detect to levels of 1% with considerable scope for detecting smaller levels. Environmental scanning electron microscope (ESEM) and energy dispersive X-ray analysis (EDX) of cation exchanged SWy-2 and a sandstone rock exposed to 2-bromopyridine (2BPY) have shown the potential of using the bromine functional group as a tag to locate the presence of swelling minerals in rocks by EDX.

Matrix Metalloproteinase-13 (MMP-13) belongs to a large family of proteolytic enzymes which are characterized by their ability to degrade the extracellular matrix components. MMP-13 appears to have a critical role in tumor invasion and metastasis. In this study, several fluorogenic probes specific for MMP-13 were designed and characterized. These synthesized probes could be modified with chelators to be applied for imaging MMP-13 in breast cancer and/or multiple myeloma models. The activity and selectivity of MMP-13 and other MMPs against these probes were studied through two approaches. It was found that these probes were cleaved by all MMPs, but MMP-13 showed the highest activity and selectivity towards these peptides. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection