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Articles 1 - 30 of 33
Full-Text Articles in Biophysics
Towards Clinical Microscopic Fractional Anisotropy Imaging, Nico Jj Arezza
Towards Clinical Microscopic Fractional Anisotropy Imaging, Nico Jj Arezza
Electronic Thesis and Dissertation Repository
Microscopic fractional anisotropy (µFA) is a diffusion-weighted magnetic resonance imaging (dMRI) metric that is sensitive to neuron microstructural features without being confounded by the orientation dispersion of axons and dendrites. µFA may potentially act as a surrogate biomarker for neurodegeneration, demyelination, and other pathological changes to neuron microstructure with greater specificity than other dMRI techniques that are sensitive to orientation dispersion, such as diffusion tensor imaging. As with many advanced imaging techniques, µFA is primarily used in research studies and has not seen use in clinical settings.
The primary goal of this Thesis was to assess the clinical viability of …
Elucidating The Biomechanics Of Mertk-Mediated Efferocytosis, Brandon Hayato Dickson
Elucidating The Biomechanics Of Mertk-Mediated Efferocytosis, Brandon Hayato Dickson
Electronic Thesis and Dissertation Repository
Macrophages are key mediators of efferocytosis – the phagocytic engulfment and removal of apoptotic cells. During engulfment, the coordinated activity of efferocytic receptors induces the remodeling of the actin cytoskeleton, which facilitates the envelopment of the cell by the plasma membrane. Mer receptor tyrosine kinase (MERTK) is a crucial efferocytic receptor, but its role during actin remodeling is not well understood. Previously, our lab showed that MERTK is an activator of β2 integrins – which are comprised of receptors known to induce the actin polymerization that is required for engulfment. We hypothesized that MERTK is an indirect stimulator of …
Novel 129xe Magnetic Resonance Imaging And Spectroscopy Measurements Of Pulmonary Gas-Exchange, Alexander M. Matheson
Novel 129xe Magnetic Resonance Imaging And Spectroscopy Measurements Of Pulmonary Gas-Exchange, Alexander M. Matheson
Electronic Thesis and Dissertation Repository
Gas-exchange is the primary function of the lungs and involves removing carbon dioxide from the body and exchanging it within the alveoli for inhaled oxygen. Several different pulmonary, cardiac and cardiovascular abnormalities have negative effects on pulmonary gas-exchange. Unfortunately, clinical tests do not always pinpoint the problem; sensitive and specific measurements are needed to probe the individual components participating in gas-exchange for a better understanding of pathophysiology, disease progression and response to therapy.
In vivo Xenon-129 gas-exchange magnetic resonance imaging (129Xe gas-exchange MRI) has the potential to overcome these challenges. When participants inhale hyperpolarized 129Xe gas, it …
Conformational Dynamics And Aggregation Of Thermally Stressed Proteins Studied By Hydrogen/Deuterium Exchange Mass Spectrometry, Nastaran Nosrat Tajoddin
Conformational Dynamics And Aggregation Of Thermally Stressed Proteins Studied By Hydrogen/Deuterium Exchange Mass Spectrometry, Nastaran Nosrat Tajoddin
Electronic Thesis and Dissertation Repository
Proteins perform various biological functions, e.g., as enzymes or transporters. In addition to naturally occurring proteins, the use of protein therapeutic drugs for treating cancer and other diseases is a rapidly growing area. A thorough biophysical characterization of proteins and protein therapeutics opens the door to a more comprehensive understanding of their role in health and disease. This dissertation aims to expand the capabilities of an existing technique (Hydrogen Deuterium Exchange Mass Spectrometry, HDX-MS), which is widely used for probing protein structure and dynamics. Conventionally, HDX-MS experiments are performed as a function of labelling time. Here we aim to establish …
The Hydrophobic Residues In Amino Terminal Domains Of Cx46 And Cx50 Are Important For Their Gap Junction Channel Ion Permeation And Gating, Roa'a Jaradat
Electronic Thesis and Dissertation Repository
Connexins are ubiquitous transmembrane proteins that assemble to form intercellular channels, called gap junctions (GJs). The amino terminal (NT) domain and residues within this domain have been shown to be important for both Vj-gating and single channel conductance (γj) of several GJs including Cx46 and Cx50. High-resolution structures of Cx46 and Cx50 GJs were recently resolved showing that NT domain folds into the inner pore where hydrophobic residues are packed against M1/2 domains stabilizing open-state conformation. We studied functional properties of GJs formed by several point variants at NT (Cx46 L10I, N13E, A14V, Q15N and Cx50 …
Validation Of Arterial Spin Labeling For Longitudinal Monitoring And Differential Diagnosis Of Frontotemporal Dementia, Tracy Ssali
Electronic Thesis and Dissertation Repository
Frontotemporal dementia (FTD) is a devastating neurodegenerative disease characterized by a rapid decline in behavioural, language, and motor abilities. Advances in the understanding of FTD genetics and pathophysiology, and the subsequent development of novel disease modifying treatments have highlighted the need for tools to assess their efficacy. While structural magnetic resonance imaging (MRI) and functional imaging with 18F-flurodeoxyglucose (FDG) positron emission tomography (PET) are used for clinical diagnosis, structural changes are subtle at the early stages and PET imaging is expensive and access limited. Given the coupling of cerebral blood flow (CBF) to energy metabolism, an attractive alternative is …
Phase Imaging For Reducing Macrovascular Signal Contributions In High-Resolution Fmri, Olivia W. Stanley
Phase Imaging For Reducing Macrovascular Signal Contributions In High-Resolution Fmri, Olivia W. Stanley
Electronic Thesis and Dissertation Repository
High resolution functional MRI allows for the investigation of neural activity within the cortical sheet. One consideration in high resolution fMRI is the choice of which sequence to use during imaging, as all methods come with sensitivity and specificity tradeoffs. The most used fMRI sequence is gradient-echo echo planar imaging (GE-EPI) which has the highest sensitivity but is not specific to microvasculature. GE-EPI results in a signal with pial vessel bias which increases complexity of performing studies targeted at structures within the cortex. This work seeks to explore the use of MRI phase signal as a macrovascular filter to correct …
Exogenous Surfactant As A Delivery Vehicle For Intrapulmonary Therapeutics, Brandon J. Baer
Exogenous Surfactant As A Delivery Vehicle For Intrapulmonary Therapeutics, Brandon J. Baer
Electronic Thesis and Dissertation Repository
As an organ system, the lung has unique advantages and disadvantages for direct drug delivery. Its contact with the external environment allows for the airways to be easily accessible to intrapulmonary delivery. However, its complex structure, which divides into more narrow airways with each branch, can make direct delivery to the remote alveoli challenging. The objective of this thesis was to overcome this issue by using exogenous surfactant, a lipoprotein complex used to treat neonatal respiratory distress syndrome, as a carrier for pulmonary therapeutics. It was hypothesized that therapeutics administered with a surfactant vehicle would display enhanced delivery to the …
A Quantitative Assessment Of Hemodynamic And Histological Parameters In The Mdx Mouse Model, Sarah Hakim
A Quantitative Assessment Of Hemodynamic And Histological Parameters In The Mdx Mouse Model, Sarah Hakim
Electronic Thesis and Dissertation Repository
Duchenne muscular dystrophy (DMD) is one of the most commonly inherited musculoskeletal disorders affecting 1 in 3500 boys worldwide. The disorder is due to a lack of functional dystrophin protein, which, in turn, results in a loss of cell membrane integrity in skeletal, cardiac muscle and the brain leading to changes in perfusion. As such, within DMD tissue, necrosis is commonly observed, and it has been previously hypothesized that this may be due to a reduction in regional blood supply. Here, we aim to measure hemodynamic changes during disease progression in DMD (Mdx/Utrn+/+) mice, using dynamic contrast enhanced …
Developing Sodium Mri For Longitudinal Assessment Of Chemotherapy Of Glioma In A Rat Model Of Cancer, Xin Yue Wang
Developing Sodium Mri For Longitudinal Assessment Of Chemotherapy Of Glioma In A Rat Model Of Cancer, Xin Yue Wang
Electronic Thesis and Dissertation Repository
Glioblastoma (GBM) is an aggressive cancer which presents significant challenges for disease management and treatment. Tissue sodium concentration (TSC) is a sensitive indicator of disease and changes in TSC can be used as a potential biomarker for treatment response. A longitudinal orthotopic C6 GBM model was used to study changes in TSC due to cancer. Animals were imaged with contrast enhanced T1-weighted, T2-weighted and sodium MRI and were either un-treated or received temozolomide (TMZ) treatment. Accurate assessment of TSC was possible for tumour volumes greater than 150mm3 using 3mm isotropic imaging voxels. TSC increased with …
Ischemic Stroke Thrombus Characterization Through Quantitative Magnetic Resonance Imaging, Spencer D. Christiansen
Ischemic Stroke Thrombus Characterization Through Quantitative Magnetic Resonance Imaging, Spencer D. Christiansen
Electronic Thesis and Dissertation Repository
Stroke is a pervasive, devastating disease and remains one of the most challenging conditions to treat. In particular, risk of recurrence is dramatically heightened after a primary stroke and requires urgent preventative therapy to effectively mitigate. However, the appropriate preventative therapy depends on the underlying source of the stroke, known as etiology, which is challenging to determine promptly. Current diagnostic tests for determining etiology underwhelm in both sensitivity and specificity, and in as much as 35% of cases etiology is never determined. In ischemic stroke, the composition of the occluding thrombus, specifically its red blood cell (RBC) content, has been …
Non-Invasive Quantification Of Cerebral Oxygen Metabolism By Hybrid Positron Emission Tomography/Magnetic Resonance Imaging, Lucas Diovani Lopes Narciso
Non-Invasive Quantification Of Cerebral Oxygen Metabolism By Hybrid Positron Emission Tomography/Magnetic Resonance Imaging, Lucas Diovani Lopes Narciso
Electronic Thesis and Dissertation Repository
Although positron emission tomography (PET) remains the gold standard for quantifying cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2), the procedures are invasive and complex, requiring arterial sampling and accounting for blood-borne activity. Non-invasive methods generally require extracting an image-derived input function (IDIF) from the carotid arteries; however, these methods are sensitive to partial volume errors due to the poor spatial resolution of PET. Hybrid PET/magnetic resonance imaging (MRI) offers an alternative non-invasive approach by using MRI to calibrate PET data. PET/MR imaging of oxidative metabolism (PMROx) is a reference-based approach that uses whole-brain (WB) …
Cardiac Modelling Techniques To Predict Future Heart Function And New Biomarkers In Acute Myocardial Infarction, Sergio C. H. Dempsey
Cardiac Modelling Techniques To Predict Future Heart Function And New Biomarkers In Acute Myocardial Infarction, Sergio C. H. Dempsey
Electronic Thesis and Dissertation Repository
Fundamental to treatment planning for patients that have suffered myocardial infarction are predictive biomarkers and risk factors. Important among these in terms of a patient’s treatment plan or prognosis are the contractility of the damaged myofibers, final infarct volume, and poor infarct healing rate. Proposed and developed in this thesis are techniques to predict these biomarkers and risk factors using cardiac biomechanical modelling. One of the developed techniques was a CT compatible shape optimization technique which can predict the contraction force of healthy, and stunned myofibers within 6.3% and the distribution of potentially necrotic myofibers within 10% accuracy. The second …
The Role Of Heat Shock Protein 90 In The Keap1/Nrf2 Mediated Oxidative-Stress Response, Zheng Song
The Role Of Heat Shock Protein 90 In The Keap1/Nrf2 Mediated Oxidative-Stress Response, Zheng Song
Electronic Thesis and Dissertation Repository
Oxidative and proteotoxic stress are common hallmarks of Neurodegenerative diseases (NDs). Cellular proteostasis is maintained through Heat shock protein (Hsp) 90 and Stress-inducible protein 1 (STIP1) modulating the stability of their substrates (clients). Hsp90/heat shock factor (HSF)1 pathway activation attenuates proteotoxicity. Meanwhile, activating the Kelch-like ECH associated protein 1 (Keap1)/ nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway combats oxidative stress. Numerous studies attempted to individually manipulate the expression of Hsp90 or Nrf2 to treat NDs.
Novel interactions of Hsp90 with Nrf2 and Keap1 were discovered via yeast-2-hybrid screening (unpublished data). We analyzed their interactions through NMR spectroscopy, ITC, protein-binding assay, …
Excess No Stabilizes The Luminal Domain Of Stim2 In A Cys-Specific Manner Thereby Regulating Basal Calcium Homeostasis And Store-Operated Calcium Entry, Matthew Novello
Excess No Stabilizes The Luminal Domain Of Stim2 In A Cys-Specific Manner Thereby Regulating Basal Calcium Homeostasis And Store-Operated Calcium Entry, Matthew Novello
Electronic Thesis and Dissertation Repository
Stromal-interaction molecule 2 (STIM2) is an endoplasmic reticulum (ER) membrane-inserted Ca2+-sensing protein which, together with the plasma membrane Ca2+ channel Orai1, regulates basal Ca2+ homeostasis and store-operated Ca2+ entry (SOCE). Recent evidence suggests that S-nitrosylation, which is the covalent attachment of a nitric oxide (NO) moiety to a cysteine thiol, can attenuate the function of the paralog STIM1 protein. Compared to STIM1, STIM2 also functions as a basal Ca2+ homeostatic feedback regulator. Therefore, the objective of my study was to evaluate the susceptibility of STIM2 to S-nitrosylation and the effects that this …
Monocyte Mri Relaxation Rates Are Regulated By Extracellular Iron And Hepcidin, Praveen S.B Dassanayake
Monocyte Mri Relaxation Rates Are Regulated By Extracellular Iron And Hepcidin, Praveen S.B Dassanayake
Electronic Thesis and Dissertation Repository
Monocytes are an important immune cell type in chronic inflammatory conditions like atherosclerosis and heart failure. The increase in number of monocytes released to the peripheral blood circulation, the differentiation of monocytes to macrophages, and the presence of different macrophage subpopulations during pro- and anti-inflammatory stages of tissue injury may provide markers for monitoring inflammation. In particular, changes in monocyte iron metabolism during an inflammatory response may increase the possibility of tracking these immune cells non-invasively using magnetic resonance imaging (MRI). When secretion of the polypeptide hormone hepcidin is stimulated during inflammation, it binds the iron export protein ferroportin (FPN) …
Microvascular Stenosis In Critical Limb Ischemia: Role Of Partial Endothelial To Mesenchymal Transition, Jacqueline M. Chevalier
Microvascular Stenosis In Critical Limb Ischemia: Role Of Partial Endothelial To Mesenchymal Transition, Jacqueline M. Chevalier
Electronic Thesis and Dissertation Repository
Critical limb ischemia (CLI) is a widespread and debilitating manifestation of atherosclerosis. Unfortunately, revascularization strategies are often precluded or unsuccessful, resulting in amputation. A major reason for treatment failure is likely co-existing abnormalities in the microvasculature. However, the specific microvascular defects present in end-stage PAD in humans remain unknown.
The purpose of this study was to delineate abnormalities in the microvascular wall in the critically ischemic skeletal muscle of patients with CLI.
To elucidate the microvascular landscape in CLI, we studied human tibialis anterior and gastrocnemius muscles harvested from below-knee amputations of 10 individuals with CLI. Control muscles are from …
Investigation Of Flow Disturbances And Multi-Directional Wall Shear Stress In The Stenosed Carotid Artery Bifurcation Using Particle Image Velocimetry, Amanda L. Dicarlo
Investigation Of Flow Disturbances And Multi-Directional Wall Shear Stress In The Stenosed Carotid Artery Bifurcation Using Particle Image Velocimetry, Amanda L. Dicarlo
Electronic Thesis and Dissertation Repository
Hemodynamics and shear forces are associated with pathological changes in the vascular wall and its function, resulting in the focal development of atherosclerosis. Flow complexities that develop in the presence of established plaques create environments favourable to thrombosis formation and potentially plaque rupture leading to stroke. The carotid artery bifurcation is a common site of atherosclerosis development. Recently, the multi-directional nature of shear stress acting on the endothelial layer has been highlighted as a risk factor for atherogenesis, emphasizing the need for accurate measurements of shear stress magnitude as well direction. In the absence of comprehensive patient specific datasets numerical …
Investigating The Cortical, Metabolic And Behavioral Effects Of Transcranial Direct Current Stimulation In Preparation For Combined Rehabilitation, Kayla N. Ryan
Electronic Thesis and Dissertation Repository
The goal of this thesis was to determine the cortical reorganization that occurs in patients with cervical spondylotic myelopathy (CSM) after surgical decompression and to implement this knowledge into a new rehabilitation strategy. Transcranial direct current stimulation (tDCS) is a non-invasive technique to modulate human behavior. Due to the novel electrode montage used, it was first pertinent that we determine how tDCS would modulate cortical, metabolic and motor behavior in healthy individuals.
We observed the longitudinal functional adaptations that occur in patients with CSM using functional MRI. Enhanced excitation of supplementary motor area (SMA) was observed following surgical decompression and …
First-Order Statistical Speckle Models Improve Robustness And Reproducibility Of Contrast-Enhanced Ultrasound Perfusion Estimates, Matthew R. Lowerison
First-Order Statistical Speckle Models Improve Robustness And Reproducibility Of Contrast-Enhanced Ultrasound Perfusion Estimates, Matthew R. Lowerison
Electronic Thesis and Dissertation Repository
Contrast-enhanced ultrasound (CEUS) permits the quantification and monitoring of adaptive tumor responses in the face of anti-angiogenic treatment, with the goal of informing targeted therapy. However, conventional CEUS image analysis relies on mean signal intensity as an estimate of tracer concentration in indicator-dilution modeling. This discounts additional information that may be available from the first-order speckle statistics in a CEUS image. Heterogeneous vascular networks, typical of tumor-induced angiogenesis, lead to heterogeneous contrast enhancement of the imaged tumor cross-section.
To address this, a linear (B-mode) processing approach was developed to quantify the change in the first-order speckle statistics of B-mode cine …
Assessment Of Post-Treatment Imaging Changes Following Radiotherapy Using Magnetic Susceptibility Techniques, Jean-Guy Belliveau
Assessment Of Post-Treatment Imaging Changes Following Radiotherapy Using Magnetic Susceptibility Techniques, Jean-Guy Belliveau
Electronic Thesis and Dissertation Repository
Radiation therapy (RT) is a common treatment for brain neoplasms and is used alone or in combination with other therapies. The use of RT has been found to be successful in controlling tumors and extending the overall survival of patients; however, there are many unanswered questions regarding radiotherapy effects in the normal brain surrounding or infiltrated by tumor. Changes to the vascular and parenchyma have been documented, and more recently inflammatory mechanisms have been postulated to play a role in radiation injury. Traditional imaging techniques used within the clinic (CT and MRI) are often lacking in their ability to differentiate …
Hyperpolarized 129xe Magnetic Resonance Imaging Of Radiation-Induced Lung Injury, Ozkan Doganay
Hyperpolarized 129xe Magnetic Resonance Imaging Of Radiation-Induced Lung Injury, Ozkan Doganay
Electronic Thesis and Dissertation Repository
Lung cancer is the largest contributor to cancer-related mortality worldwide. Only 20% of stage III non-small cell lung cancer patients survive after 5-years post radiation therapy (RT). Although RT is an important treatment modality for lung cancer, it is limited by Radiation-Induced Lung Injury (RILI). RILI develops in two phases: (i) the early phase (days-weeks) referred to radiation pneumonitis (RP), and (ii) the late phase (months). There is a strong interest in early detection of RP using imaging to improve outcomes of RT for lung cancer. This thesis describes a promising approach based on 129Xe gas as a contrast …
Resting And Functional Magnetic Resonance Spectroscopy Of Glutamate In Schizophrenia At 7 Tesla, Reggie E. Taylor
Resting And Functional Magnetic Resonance Spectroscopy Of Glutamate In Schizophrenia At 7 Tesla, Reggie E. Taylor
Electronic Thesis and Dissertation Repository
Schizophrenia is a debilitating disease that affects about 1% of the population. Current therapeutic interventions mostly target dopaminergic neurotransmission but are not effective in treating all symptoms. There is growing evidence to support involvement of glutamatergic neurotransmission, which may better account for the symptomatology of schizophrenia.
Glutamate concentrations can be measured in vivo using magnetic resonance spectroscopy (MRS). Stronger MRIs provide benefits for MRS, but they also present challenges. Simulations were designed to examine how MRI field strength influences metabolite quantification. Glutamate and its metabolic precursor, glutamine, were more reliably and independently quantified with higher MRI field strengths, showing a …
Novel Techniques For Investigating The Regulation Of Skeletal Muscle Hemodynamics, Baraa K. Al-Khazraji
Novel Techniques For Investigating The Regulation Of Skeletal Muscle Hemodynamics, Baraa K. Al-Khazraji
Electronic Thesis and Dissertation Repository
The effect of the sympathetic nervous system (SNS) on blood flow distribution within skeletal muscle microvasculature is conditional upon regional activation of SNS receptors. Due to a lack of appropriate experimental models and techniques, no study has systematically evaluated the effect of SNS receptor activation in continuously branching skeletal muscle arteriolar trees. In line with previous work, we hypothesize that there will be a spatially-dependent distribution of sympathetic receptor activation along the arteriolar tree. Specifically, we anticipate a progressive decrease of adrenergic activation and a progressive increase of peptidergic and purinergic activation with increasing arteriolar order. We developed a novel …
Towards The Development Of A Maga Reporter Gene Expression Construct For Magnetic Resonance Imaging, Karina Quiaoit
Towards The Development Of A Maga Reporter Gene Expression Construct For Magnetic Resonance Imaging, Karina Quiaoit
Electronic Thesis and Dissertation Repository
Development of methods to monitor cellular activity with magnetic resonance imaging (MRI) provides a powerful tool for studying disease progression and monitoring therapy. This thesis investigates components necessary for development of reporter gene expression for MRI, to track Nkx2.5 transcription factor activity during tumour growth and, in the future, to calibrate MR contrast against a well-known optical reporter gene, like firefly luciferase. In human MCF-7 breast cancer cells, Nkx2.5 is induced by all-trans retinoic acid (tRA) and activates a minimal promoter of the rat sodium iodide symporter (rNISmin) gene. Here, we used firefly luciferase reporter gene expression to examine a …
Acquisition And Reconstruction Techniques For Fat Quantification Using Magnetic Resonance Imaging, Abraam S. Soliman
Acquisition And Reconstruction Techniques For Fat Quantification Using Magnetic Resonance Imaging, Abraam S. Soliman
Electronic Thesis and Dissertation Repository
Quantifying the tissue fat concentration is important for several diseases in various organs including liver, heart, skeletal muscle and kidney. Uniquely, MRI can separate the signal from water and fat in-vivo, rendering it the most suitable imaging modality for non-invasive fat quantification. Chemical-shift-encoded MRI is commonly used for quantitative fat measurement due to its unique ability to generate a separate image for water and fat. The tissue fat concentration can be consequently estimated from the two images. However, several confounding factors can hinder the water/fat separation process, leading to incorrect estimation of fat concentration.
The inhomogeneities of the main …
Oriented Collagen And Applications Of Waveguide Evanescent Field Scattering (Wefs) Microscopy, Qamrun Nahar
Oriented Collagen And Applications Of Waveguide Evanescent Field Scattering (Wefs) Microscopy, Qamrun Nahar
Electronic Thesis and Dissertation Repository
In this thesis, Waveguide Evanescent Field Scattering (WEFS) microscopy is developed as a non-invasive, label-free live cell imaging technique. This new high-contrast imaging can be employed to study the first hundred nanometers from the surface as it utilizes the evanescent field of a waveguide as the illumination source. Previously, waveguide evanescent field fluorescence (WEFF) microscopy was developed as a fluorescence imaging technique comparable to the total internal reflection fluorescent (TIRF) microscopy. Both the WEFF and WEFS technique utilizes the same fundamental concepts except in WEFS microscopy imaging is accomplished without the application of any fluorescent labeling. In this work, bacterial …
Metabolic Imaging Of Early Radiation-Induced Lung Injury Using Hyperpolarized 13c-Pyruvate In Rodent Lungs, Kundan Thind
Metabolic Imaging Of Early Radiation-Induced Lung Injury Using Hyperpolarized 13c-Pyruvate In Rodent Lungs, Kundan Thind
Electronic Thesis and Dissertation Repository
Lung cancer is the leading cause of cancer related death. Radiation therapy is a prominent treatment method but leads to adverse consequences. Radiation-Induced Lung Injury (RILI) is the primary adverse consequence that limits further radiation therapy and develops in 5-37% of the treated patients. RILI proceeds in two distinct phases: a) early and reversible Radiation Pneumonitis (RP), and b) late and irreversible radiation fibrosis. Clinically, Dose Volume Histogram (DVH) parameters derived from radiation therapy planning stage are used to determine outcome and severity of RP but have been demonstrated to possess a very low predictive power. Computed Tomography (CT) is …
Fabricating Cost-Effective Nanostructures For Biomedical Applications, Erden Ertorer
Fabricating Cost-Effective Nanostructures For Biomedical Applications, Erden Ertorer
Electronic Thesis and Dissertation Repository
In this thesis we described inexpensive alternatives to fabricate nanostructures on planar substrates and provided example applications to discuss the efficiency of fabricated nanostructures.
The first method we described is forming large area systematically changing multi-shape nanoscale structures on a chip by laser interference lithography. We analyzed the fabricated structures at different substrate positions with respect to exposure time, exposure angle and associated light intensity profile. We presented experimental details related to the fabrication of symmetric and biaxial periodic nanostructures on photoresist, silicon surfaces, and ion-milled glass substrates. Behavior of osteoblasts and osteoclasts on the nanostructures was investigated. These results …
Imaging Breast Cancer Progression And Lymph Node Metastases In Murine Models Using Mri And Magnetic Nanoparticles, Vasiliki Economopoulos
Imaging Breast Cancer Progression And Lymph Node Metastases In Murine Models Using Mri And Magnetic Nanoparticles, Vasiliki Economopoulos
Electronic Thesis and Dissertation Repository
Most breast cancer related deaths are caused by the spread or metastasis of the primary tumor to distant sites in the body. The lymph nodes are one of the first places where metastases can be detected and are frequently examined for macroscopic metastases to help determine course of treatment for patients. However, little is known about the significance of microscopic metastases and disseminated individual cancer cells within the nodes. The goal of this work was to use MRI to monitor the development of primary tumors and lymphatic metastases in models of breast cancer.
In this thesis, we examined the MRI …