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Design And Synthesis Of Nanomaterials For Surface-Enhanced Raman Scattering, Fuel Cell Technology, And Photonics, Pedro Camargo
Design And Synthesis Of Nanomaterials For Surface-Enhanced Raman Scattering, Fuel Cell Technology, And Photonics, Pedro Camargo
All Theses and Dissertations (ETDs)
In the first part of my dissertation, I developed two approaches for selectively probing the SERS activities of individual hot spots, i.e., experimentally detect the SERS signals only for the molecules that are trapped within the hot-spot region in individual Ag nanoparticle dimers. Then, I performed a systematic investigation on the SERS activity of individual dimers composed of two closed spaced Ag nanoparticles. By utilizing Ag nanoparticles displaying a variety of well-defined shapes, sizes and orientations to construct the dimers, I were able to precisely correlate the detected SERS signals to the specific geometry of individual hot spots. In the …
Growth Factor Delivery From Fibrin Matrics Containing Affinity-Based Delivery Systems To Treat Peripheral Nerve Injury, Matthew Wood
Growth Factor Delivery From Fibrin Matrics Containing Affinity-Based Delivery Systems To Treat Peripheral Nerve Injury, Matthew Wood
All Theses and Dissertations (ETDs)
This thesis work sought to develop a biomaterial to further the understanding of affinity-based delivery and to serve as a potential treatment for peripheral nerve injury. The use of an affinity-based delivery system: ABDS) with growth factors in a nerve guidance conduit: NGC) was hypothesized to promote nerve regeneration and functional recovery following a critical nerve defect. Evaluation of affinity-based delivery using peptides with varying binding affinity for heparin determined that peptide binding affinity for heparin affected the release rate and biological activity of nerve growth factor: NGF) in vitro. The ABDS presented biologically active NGF, which promoted neurite extension …
Engineering The Optical Properties Of Gold Nanostructures For Biomedical Applications, Leslie Au
Engineering The Optical Properties Of Gold Nanostructures For Biomedical Applications, Leslie Au
All Theses and Dissertations (ETDs)
This research investigated the synthesis and optical properties of Au nanostructures with an aim to use them as imaging agents and photothermal transducers for the diagnosis and treatment of cancer. I have produced Au nanocages with hollow interiors and porous walls using the galvanic replacement reaction between Ag nanocubes and AuCl4-. I have engineered these Au nanocages to have localized surface plasmon resonance: LSPR) peaks in the near-infrared region with strong absorption. These optical properties allow for the imaging of biological tissues at deeper penetration and the photoablation of cancer. By replacing AuCl4- with AuCl2 …
Electrocorticographic Neural Correlates Of Arm Movements And Associated Goal Orientation In Humans, Nicholas Anderson
Electrocorticographic Neural Correlates Of Arm Movements And Associated Goal Orientation In Humans, Nicholas Anderson
All Theses and Dissertations (ETDs)
This thesis analyzed the cortical representation of arm kinematics, target encoding, and goal encoding using subdural electrocorticographic: ECoG) recordings in humans. Using a joystick-based visuomotor task, subjects performed both a standard, delayed match-to-sample center-out task as well as a circular tracing task. Spectral analyses of the ECoG signals clearly showed significant cosine tuning for hand velocity, direction, position and speed throughout the cortex. In particular, velocity tuning was best represented spectrally in a high gamma band from around 90-150 Hz in the primary motor cortical regions. In dorsolateral prefrontal cortex: DLPFC), cortical activity in the 150-250 Hz band of the …
Investigations Into The Ulnar Response To Mechanical Stimuli Activating Lamellar And Woven Bone Formation, Jennifer Mckenzie
Investigations Into The Ulnar Response To Mechanical Stimuli Activating Lamellar And Woven Bone Formation, Jennifer Mckenzie
All Theses and Dissertations (ETDs)
Woven and lamellar bone formation can be stimulated using mechanical loading. Woven bone forms rapidly in response to damaging loading in a disorganized manner with low mineral density. In contrast, lamellar bone formation can be induced in the absence of damage, and is characterized by its slow, organized deposition and high density. In this dissertation, we first examined the molecular response to woven and lamellar bone formation using damaging and non-damaging dynamic loading protocols, respectively. We observed a significant increase in gene expression related to angiogenesis, cell proliferation and osteogenesis prior to woven bone formation, with significantly lower levels of …
Development And Implementation Of Fully 3d Statistical Image Reconstruction Algorithms For Helical Ct And Half-Ring Pet Insert System, Daniel Keesing
Development And Implementation Of Fully 3d Statistical Image Reconstruction Algorithms For Helical Ct And Half-Ring Pet Insert System, Daniel Keesing
All Theses and Dissertations (ETDs)
X-ray computed tomography: CT) and positron emission tomography: PET) have become widely used imaging modalities for screening, diagnosis, and image-guided treatment planning. Along with the increased clinical use are increased demands for high image quality with reduced ionizing radiation dose to the patient. Despite their significantly high computational cost, statistical iterative reconstruction algorithms are known to reconstruct high-quality images from noisy tomographic datasets. The overall goal of this work is to design statistical reconstruction software for clinical x-ray CT scanners, and for a novel PET system that utilizes high-resolution detectors within the field of view of a whole-body PET scanner. …
Contributions To The Methodology Of Electrocardiographic Imaging (Ecgi) And Application Of Ecgi To Study Mechanisms Of Atrial Arrhythmia, Post Myocardial Infarction Electrophysiological Substrate, And Ventricular Tachycardia In Patients, Yong Wang
All Theses and Dissertations (ETDs)
ABSTRACT OF THE DISSERTATION Contributions to the Methodology of Electrocardiographic Imaging: ECGI) and Application of ECGI to Study Mechanisms of Atrial Arrhythmia, Post Myocardial Infarction Electrophysiological Substrate, and Ventricular Tachycardia in Patients by Yong Wang Doctor of Philosophy in Biomedical Engineering Washington University in St. Louis, 2009 Professor Yoram Rudy, Chair Electrocardiographic Imaging: ECGI) is a noninvasive imaging modality for cardiac electrophysiology and arrhythmia. ECGI reconstructs epicardial potentials, electrograms and isochrones from body-surface electrocardiograms combined with heart-torso geometry from computed tomography: CT). The application of a new meshless method, the Method of Fundamental Solutions: MFS) is introduced to ECGI with …
Expression Analysis And Stem Cell Engineering, Cara Rieger
Expression Analysis And Stem Cell Engineering, Cara Rieger
All Theses and Dissertations (ETDs)
The overall goal of the thesis was to develop tools to advance Investigations of stem cells in tissue engineering therapeutics for neurodegenerative disease and spinal cord injury. Two tools to characterize cell fate and a tool to separate a subset of neural cells were developed and evaluated. In the first study, a digital PCR technology, called polonies, was applied to measure mRNA from several key stem cell genes in small numbers of ES cells. Due to its properties, we hypothesized that polonies would be uniquely poised to profile stem cells. Polonies were counted for Oct3 in a sample of 10 …
Improving Biocompatibility By Controlling Protein Adsorption: Modification And Design Of Biomaterials Using Poly(Ethylene Glycol) Microgels And Microspheres, Evan Scott
All Theses and Dissertations (ETDs)
Guided by the clinical needs of patients and developments in biology and materials science, the primary focus of the biomaterials field remains at the solid/liquid interface between biomaterial surfaces and biological fluids. For blood-contacting devices, biological responses are initially elicited and directed by proteins that adsorb from this multicomponent solution to form thin films on their surfaces. The identity, conformation, and quantity of adsorbed proteins are related to the properties of a material's surface. For example, hydrophobic surfaces tend to be thrombotic via interactions between platelets and adsorbed fibrinogen, while surface-activation of specific enzymes initiates the coagulation cascade on hydrophilic …
A Framework For Temperature Imaging Using The Change In Backscattered Ultrasonic Signals, Yuzheng Guo
A Framework For Temperature Imaging Using The Change In Backscattered Ultrasonic Signals, Yuzheng Guo
All Theses and Dissertations (ETDs)
Hyperthermia is a cancer treatment that elevates tissue temperature to 40 to 43oC. It would benefit from a non-invasive, safe, inexpensive and convenient thermometry to monitor heating patterns. Ultrasound is a modality that meets these requirements. In our initial work, using both prediction and experimental data, we showed that the change in the backscattered energy: CBE) is a potential parameter for TI. CBE, however, was computed in a straightforward yet ad hoc manner. In this work, we developed and exploited a mathematical representation for our approach to TI to optimize temperature accuracy. Non-thermal effects of noise and motion confound the …
Feature Topography And Sound Intensity Level Encoding In Primary Auditory Cortex, Paul Watkins
Feature Topography And Sound Intensity Level Encoding In Primary Auditory Cortex, Paul Watkins
All Theses and Dissertations (ETDs)
The primary auditory cortex: A1) in mammals is one of the first areas in the neocortex that receives auditory related spiking activity from the thalamus. Because the neocortex is implicated in regulating high-level brain phenomena, such as attention and perception, it is therefore important in regards to these high-level behaviors to understand how sounds are represented and transformed by neuronal circuits in this area. The topographic organization of neuronal responses to auditory features in A1 provides evidence for potential mechanisms and functional roles of this neural circuitry. This dissertation presents results from models of topographic organization supporting the notion that …