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Full-Text Articles in Biomedical Engineering and Bioengineering

Role Of P-Glycoprotein In Alzheimer’S Disease For Enhanced Brain Elimination Of Amyloid-Β, Hope Holt Apr 2019

Role Of P-Glycoprotein In Alzheimer’S Disease For Enhanced Brain Elimination Of Amyloid-Β, Hope Holt

Theses and Dissertations

Alzheimer’s disease (AD), the most common form of neurodegenerative disorder, is characterized by deposition of amyloid-β (Aβ) plaques in the brain. Aβ monomer undergoes nucleation to form oligomers, then soluble aggregates, then fibrils which make up the plaques. Aβ oligomer species are believed to be the most neurotoxic aggregate species. Currently under investigation is a mechanism for Aβ removal from the brain, across the blood-brain barrier (BBB). P-glycoprotein (P-gp) is a membrane-bound efflux protein located on the apical, or blood, side of the BBB, which transports a wide variety of substrates. Further complicating this potential clearance mechanism is the ...


Experimental Study Of Free-Solution Separation Under Pulsed Electrophoresis In Microchip, Xin Liu Apr 2019

Experimental Study Of Free-Solution Separation Under Pulsed Electrophoresis In Microchip, Xin Liu

Theses and Dissertations

Microchip electrophoresis (MCE) is a promising analytical tool started more than two decades. With the characteristics of short analysis time, trace level sample, high- throughput and easily integration, lots of efforts have been done with the transportation of the applications from capillary to microfabricated devices. However, with the complex designs on microchip rather than a single straight capillary channel, the strategies and approaches have to be figured out under the challenges of sample introduction, the improvement of separation conditions and the detection, for instance.

In miniaturized microchip, the separation channel is reduced to several centimeters or less, fast and quality ...


Rage Expression And Inflammation In Alzheimer’S Disease: In Vitro Model Development And Investigation Of A Potential Peptoid Inhibitor, Lauren Michell Wolf Apr 2019

Rage Expression And Inflammation In Alzheimer’S Disease: In Vitro Model Development And Investigation Of A Potential Peptoid Inhibitor, Lauren Michell Wolf

Theses and Dissertations

Despite the increasing prevalence of Alzheimer’s disease (AD), efforts to establish a definitive treatment or cure have met with little success. Many previous therapeutic strategies for AD have focused on the aggregation and accumulation of amyloid-b (Ab) in the brain, concentrating on its small intermediate aggregates as the primary targets to ameliorate neurotoxicity and damage. This approach has yielded little progress, and more recent discussions have shifted to strategies geared toward a multifaceted pathology, with chronic neuroinflammation emerging as an important factor in the disease etiology and progression.

The receptor for advanced glycation end-products, or RAGE, is ...


Three-Dimensional Collagen Tubes For In Vitro Modeling, Rebecca Jones Apr 2019

Three-Dimensional Collagen Tubes For In Vitro Modeling, Rebecca Jones

Theses and Dissertations

Collagen type I represents a novel material for three-dimensional in vitro models. While two-dimensional models are typically inadequate for recreating the complex processes of the body, collagen provides a three-dimensional basis with a variety of applications, including remodeling of vascular cells under tension and vascular stenosis. Smooth muscle cells reorganize and reconstruct their environment differently under conditions of tensions, such as with sutures, or under conditions without applied external tension. Vascular stenosis, the abnormal narrowing of blood vessels, arises from defective developmental processes or atherosclerosis-related adult pathologies. Stenosis triggers a series of adaptive cellular responses that induces adverse remodeling, which ...


Turning Up Antitumor Immunity Against Breast Cancer, Johnie Hodge Oct 2018

Turning Up Antitumor Immunity Against Breast Cancer, Johnie Hodge

Theses and Dissertations

Breast cancer is the most common cancer in women worldwide, and is the second leading cause of cancer-related death in spite of significant advances in treatment and emphasis on early diagnosis. While treatment of localized disease is often successful, metastatic breast cancer, especially of the triple negative molecular subtype, carries a much poorer prognosis. The significant role of the immune system in the progression from localized to metastatic disease is becoming more and more appreciated. Tumor escape from immune surveillance and immune suppression in the tumor microenvironment have become therapeutic targets in addition to the traditional goals of directly killing ...


Increasing Drug Delivery Efficacy Of Drug-Coated Balloons, Alexander Galan, Eric Bidinger, Franco Godoy, Shrusti Patel Apr 2018

Increasing Drug Delivery Efficacy Of Drug-Coated Balloons, Alexander Galan, Eric Bidinger, Franco Godoy, Shrusti Patel

Senior Theses

Peripheral artery disease (PAD), the narrowing of peripheral arteries located in areas such as the arms and legs, is a common disease that affects 12% to 20% of people over 65. Numerous therapies have been developed to treat PAD, the most recent technology being drug-coated balloons. Drug-coated balloons release drugs, such as Paclitaxel (PTX), into the arterial wall during balloon angioplasty to locally treat PAD. Current levels of drug transfer from the balloon to the vascular endothelium are at a low 10%-18%. Our Biomedical Engineering Senior Design project aims to increase drug delivery of drug-coated balloons by manipulating the ...


Osteon Mimetic Scaffolding, Janay Clytus Apr 2018

Osteon Mimetic Scaffolding, Janay Clytus

Senior Theses

The purpose of this research is to provide an alternative to naturally derived bone grafts. There is a gap in the supply of donors and the demand of bone tissue. Artificial scaffold creation can work as an implant and decrease the shortage of bone grafts and increase the range of injuries that can be repaired. Current research focuses on optimizing mechanical properties such as porosity, improving vascularization using cells, and generating osteoconductivity. For osteodifferentiation, mesenchymal stem cells (MSCs) can differentiate into mesodermal lineages such as chondrocytes, osteoblasts, adipocytes, and tenocytes by supplementing cultures with lineage-specific soluble factors (Marchetti). Co-culturing ECFCs ...


Integration Of A Sensory Driven Model For Hand Grasp Function In 3d Printed Prostheses, Austin T. Hetherington Apr 2018

Integration Of A Sensory Driven Model For Hand Grasp Function In 3d Printed Prostheses, Austin T. Hetherington

Senior Theses

My Honors Thesis was completed through the Biomedical Engineering senior design project I worked on. Our project took a mechanically operated 3D printed prosthetic hand and automated the process by which it makes a grasp. The purpose of this project was to provide an affordable, automatic prosthetic hand to those either capable and incapable of wrist flexion. The current 3D printed prosthetic models require users to bend their wrist to initiate a simple grasp. However, our design took an alternative approach by using an EMG sensor placed on the ventral side of the forearm to record muscle activity, which, upon ...


Development Of Rule-Based Recognition Systems For Continuous Monitorization Of Pulse Oximetry, Brian Delehanty Apr 2018

Development Of Rule-Based Recognition Systems For Continuous Monitorization Of Pulse Oximetry, Brian Delehanty

Senior Theses

Pulse Oximeters provide a convenient, non-invasive method to quickly gather information about a patient's pulse rate (PR) and arterial blood oxygen saturation (SpO2). Many pulse oximeters lack alert systems that notify caregivers if a patient's readings go outside the healthy range, and pulse oximeters that have these mechanisms are significantly more expensive. This project set out to write a program using LabVIEW that collects pulse oximeter data via Bluetooth and generates an alert when readings persist in the abnormal range for more than fifteen seconds. Due to privacy laws that allow pulse oximeter manufacturers to not disclose ...


Optimization Of Microfluidic Chip Fabrication Via Femtosecond Laser Ablation, Kenneth Aycock Apr 2018

Optimization Of Microfluidic Chip Fabrication Via Femtosecond Laser Ablation, Kenneth Aycock

Senior Theses

Microfluidic devices have become staple tools in biomedical research and have a promising future as low cost, point-of-care (POC) diagnostic devices. Despite the advancements in microfluidic device technology, the manipulation and fabrication of these systems can be tedious and expensive. Repeatable techniques in which computer-aided designs are translated into microfluidic systems in a matter of minutes are highly desirable both for researchers and manufacturers. Laser ablation of tape substrates has shown promise in producing cost-effective, rapidly manipulable devices, but the work done thus far has utilized continuous wave lasers that perform suboptimally due to the relatively short wavelengths used and ...


Changes Of Dispersal Ability In An Isolated Population, Connor Bacon Jan 2018

Changes Of Dispersal Ability In An Isolated Population, Connor Bacon

Theses and Dissertations

Dispersal is a core mechanism in the maintenance of metapopulations. It maintains genetic diversity by connecting subpopulations and generates new populations to replace those that die out. However, as populations become more isolated, as occurs in habitat fragmentation, dispersal becomes more difficult. This should lead to selective pressure against dispersive individuals, causing a reduction in dispersal traits. Over time, this can lead to variation in dispersal traits among populations. We examine this idea using an extreme case of isolation in Euphydryas gillettii, a population that has remained completely isolated for forty years. By comparing this population to a baseline established ...


Plants As Biofactories To Produce Mammalian Tumor Suppressor Micrornas, John Lachlan Macarthur Jan 2018

Plants As Biofactories To Produce Mammalian Tumor Suppressor Micrornas, John Lachlan Macarthur

Theses and Dissertations

MicroRNAs (miRNAs) are small noncoding single stranded RNAs that are considered master regulators of gene expression. They are also an emerging class of therapeutic agents with significant potential for the prevention and treatment of many diseases, including cancer. Many different forms of cancer are associated with loss or reduced accumulation of one or more miRNAs that function as tumor suppressors. In animal models, restoration of missing tumor suppressor miRNAs prevents the initiation, progression and/or spread of the disease. However, the current absence of an efficient method for delivery of therapeutic miRNAs is a critical barrier to their use. The ...


Screening Of Novel Active Salicylic Acid Analogs And Identification Of A Bacterial Effector Targeting Key Proteins Involved In Salicylic Acid-Mediated Defense, Ian Palmer Jan 2018

Screening Of Novel Active Salicylic Acid Analogs And Identification Of A Bacterial Effector Targeting Key Proteins Involved In Salicylic Acid-Mediated Defense, Ian Palmer

Theses and Dissertations

The master regulator of salicylic acid (SA)-mediated plant defense, NPR1 (NONEXPRESSER OF PR GENES 1), and its paralogs NPR3 and NPR4 act as SA receptors. After the perception of a pathogen, plant cells produce SA in the chloroplast. In the presence of SA, NPR1 protein is reduced from oligomers to monomers, and translocated into the nucleus. There, NPR1 binds to TGA and WRKY transcription factors to induce expression of plant defense genes. EDS1 and PBS3 are two key proteins involved in SA biosynthesis. Previous research has shown that several plant pathogens produce SA hydroxylases. These pathogen-produced hydroxylases act to ...


Matrix Stiffness Modulates Mesenchymal Stem Cell Sensitivity To Geometric Asymmetry Signals, Maria Eugenia Piroli Jan 2018

Matrix Stiffness Modulates Mesenchymal Stem Cell Sensitivity To Geometric Asymmetry Signals, Maria Eugenia Piroli

Theses and Dissertations

Human stem cells hold significant potential for the treatment of various diseases. However, their use as a therapy is hampered by the limited understanding of the mechanisms by which stem cells respond to environmental stimuli. Efforts to understand extracellular biophysical cues have demonstrated the critical roles of geometric and mechanical signals in determining the fate of stem cells. The goal of this study was to explore the interplay between cell polarity and matrix stiffness in stem cell lineage specification. We hypothesize that confining cells to asymmetric extracellular matrix (ECM) islands will impart polarity at a single-cell level and result in ...


A Comprehensive Reengineering Of The Hospital Emergency Triage System, Nicholas D. Boltin Jan 2018

A Comprehensive Reengineering Of The Hospital Emergency Triage System, Nicholas D. Boltin

Theses and Dissertations

Hospital emergency triage and specifically Mass Casualty Incidents (MCIs) are of major concern with regard to treatment and patient outcomes. Traditional emergency department triage models are oversimplified and often lead to over/under triaging of patients. Furthermore, triage models do not account for the full spectrum of different types of MCIs which often results in misclassification. In this thesis, we begin by looking at traditional triage models currently being used in hospital systems and identify several shortcomings of using these models within the context of a chemical related MCI. I will then move to describe a new approach to creating ...


Modulation Of Amyloid-Β Aggregation Via Small Molecules And Glycine Zipper Alterations, Steven Zebulon Vance Jan 2018

Modulation Of Amyloid-Β Aggregation Via Small Molecules And Glycine Zipper Alterations, Steven Zebulon Vance

Theses and Dissertations

Alzheimer’s disease (AD) is the most common form of neurodegenerative disease. Nationally, AD is the 6th leading cause of death and the only top 10 killer of Americans that cannot be slowed, cured, or prevented. AD is characterized by the deposition of extracellular plaques of aggregated amyloid-β protein (Aβ). Aβ originates from the amyloid precursor protein (APP), a transmembrane protein that is cleaved to form a short and inert protein fragment called Aβ. However, Aβ undergoes a nucleation process wherein aggregates from soluble oligomers to insoluble fibrils are formed. While uncertainty remains as to the exact mechanism, studies have ...


The Visual Ecology Of Speyeria Mormonia, Natalie Sanchez Gonzalez Jan 2018

The Visual Ecology Of Speyeria Mormonia, Natalie Sanchez Gonzalez

Theses and Dissertations

Variations in environmental factors such as temperature, precipitation, and day length during larval development are known to affect morphological traits in butterflies related to their visual ecology, including eye size and wing color. These vision-related traits are important for the ability of diurnal butterfly species to detect mates, especially at long distances. Thus, changes in environmental conditions may result in phenotypic modifications to butterflies which may alter their visual ecology and subsequently, their reproductive fitness. To study the interaction of phenotypic plasticity and visual ecology in the Mormon Fritillary, Speyeria mormonia, I set up a natural-laboratory experiment at the Rocky ...


Association Between Mechanics And Biology In Vascular Graft Remodeling, David Andrew Prim Jan 2018

Association Between Mechanics And Biology In Vascular Graft Remodeling, David Andrew Prim

Theses and Dissertations

Coronary artery bypass grafting (CABG) restores myocardial perfusion in patients with severe coronary artery disease by utilizing autografts – usually at least one of the internal thoracic artery (ITA), radial artery (RA), and great saphenous vein (GSV) – to bypass stenosed regions of coronary arteries. While decades of research and clinical improvements have made CABG an indispensable procedure, tens of thousands of grafts fail each year, which is due, at least in part, to an inability of the source vessels to adapt to the altered stimuli of the coronary circulation. In this dissertation, we first quantify and compare the mechanical deviation experienced ...


Regulation Of Pituitary Progenitor Differentiation By Β-Catenin, Julie Leann Youngblood Jan 2018

Regulation Of Pituitary Progenitor Differentiation By Β-Catenin, Julie Leann Youngblood

Theses and Dissertations

The pituitary gland is a critical organ that is necessary for many physiological processes, including growth, reproduction, and stress response. These vital processes are regulated through the secretion of pituitary hormones from specialized cell types. Pituitary hormone-producing cells arise from a common pool of pituitary progenitors in the developing Rathke’s pouch, and mutations that disrupt the formation and differentiation of pituitary progenitors often result in hypopituitarism, pituitary adenomas, or craniopharyngiomas. Thus, it is necessary to determine the mechanisms of pituitary development in order to understand the ways in which these congenital defects and tumors develop and disrupt pituitary function ...


Evaluation And Modeling Of The Different Material Properties Of The Captive And Wild Diets Of Carnivores, Jill Den Outer, Bethany Janos, Elizabeth Mccourt, William Molair May 2017

Evaluation And Modeling Of The Different Material Properties Of The Captive And Wild Diets Of Carnivores, Jill Den Outer, Bethany Janos, Elizabeth Mccourt, William Molair

Senior Theses

Specific to captive BFFs, the most significant changes in cranial morphology are related to an increase in zygomatic arch width. The zygomatic arch region is the area along which the masseter muscle (a critical muscle of mastication for carnivores) is stretched3 . Mechanical stability of muscular tissues has been shown to be closely related to the structural integrity of the surrounding bones. In mice, mechanical unloading of the hind legs has been shown to induce muscular atrophy, which led to increased porosity and fragmentation in the femur and tibia4. As less force is required for a captive ferret to fully masticate ...


Atherosclerotic Plaque Adhesion Strength And Its Role In Plaque Rupture, Bilal Merei Jan 2017

Atherosclerotic Plaque Adhesion Strength And Its Role In Plaque Rupture, Bilal Merei

Theses and Dissertations

Cardiovascular diseases are disorders affecting the blood vessels and the heart. According to the World Health Organization, cardiovascular diseases are one of the leading causes of death worldwide. They are responsible for over 17.1 million deaths per year worldwide, representing 31.5% of deaths 1, 2. Atherosclerosis, a chronic inflammatory disorder affecting large arteries, is the underlying cause of many cardiovascular diseases. Plaque rupture is a serious complication of advanced atherosclerosis, often leading to life-threatening clinical consequences such as myocardial infarction (heart attack) or stroke. 75% of newly developed myocardial infarction cases are caused by atherosclerotic plaque rupture. It ...


Far-Field Optical Microscopy Based On Stimulated Emission Depletion, Yunxia Wang Jan 2017

Far-Field Optical Microscopy Based On Stimulated Emission Depletion, Yunxia Wang

Theses and Dissertations

Conventional lens-based (far-field) fluorescence microscopy is a widely used imaging technique with spatial resolution up to 150–350 nm. However, this technology cannot discern very small structural features, because the spatial resolution is limited by diffraction to about half of the wavelength of light (λ/2,λ is the wavelength of light). Hence, most of the developments in microscopy aim at improving resolution. In the past decades, stimulated emission depletion (STED) microscopy has been developed to bypass the diffraction limit for the application in biological imaging with resolution approaching the nanoscale. The basic principle of STED microscopy is to employ ...


Advancing Automated Methods For Microrna Profiling, Kia N. Zellars Jan 2017

Advancing Automated Methods For Microrna Profiling, Kia N. Zellars

Theses and Dissertations

The widespread influence of miRNAs in many biological processes and characteristic changes in expression profiles make them potential biomarkers for a range of diseases. With recent discoveries highlighting the enrichment of particular circulating miRNAs in plasma under pathological conditions, there has been a push for technological advances in miRNA profiling studies as a diagnostic tool. A standardized, automated, high-throughput method for miRNA isolation from human plasma samples was developed in this study. Samples were subject to full miRNome profiling utilizing RT-qPCR. These unique findings demonstrate that developing a distinct miRNA biomarker profile for heart failure patients is feasible and holds ...


Enabling Studies To Optimize Biomaterials For The Treatment Of Myocardial Infarction, Eva Adriana Romito Jun 2016

Enabling Studies To Optimize Biomaterials For The Treatment Of Myocardial Infarction, Eva Adriana Romito

Theses and Dissertations

The canonical mechanism of wound healing is disrupted following a myocardial infarction (MI), manifesting as an unregulated response that negatively impacts left ventricular (LV) function. This mechanism, termed post-MI remodeling, culminates in an outcome that favors progression to a systolic heart failure state and death for the patient. Therapeutic approaches following the occurrence of a MI are designed to modulate the natural remodeling process and mitigate the loss of cardiac function. The mechanics and structure of the healing infarct have been the focus of numerous pre-clinical and clinical investigations, leading to the impending clinical introduction of material injections as a ...


Orthopedic Drill System With Screw Length Measurement And Heat Sink System, Hunter Wilcox Rafoth, John Patrick Metz May 2016

Orthopedic Drill System With Screw Length Measurement And Heat Sink System, Hunter Wilcox Rafoth, John Patrick Metz

Senior Theses

Most orthopedic drills currently on the market are rudimentary tools that serve only one purpose: to drill holes through bone. Biosphinx envisions a more versatile orthopedic drill that could serve multiple purposes in the operating room. This report outlines Biosphinx’s solution to design a new orthopedic drill system that would include several key features to improve bone screw length measurement, increase patient safety, and reduce time spent in the operating room.


Next Generation Electrode, Joseph Daniel Bivona, Samuel Scott Dacus, Mary Harrell, James Frederick Weber Pike May 2016

Next Generation Electrode, Joseph Daniel Bivona, Samuel Scott Dacus, Mary Harrell, James Frederick Weber Pike

Senior Theses

This senior thesis involves the results of a biomedical engineering senior design project where the group worked with Rhythmlink International LLC. The project involved the improvement of the manufacturing process of the Invisa Electrode, a CT compatible electrode sold and manufactured by Rhythmlink. The design of the electrode pin was altered to have a hollow center, where the lead wire can be inserted and heat welded, eliminating two key components of the original design and reducing production time and cost. The type of plastic used in the electrodes was also altered to be a 40% carbon loaded conductive plastic.


Automated Image Analysis And Spatial Computational Modeling Of Nf-Kb In Cerebrovascular Endothelial Cells, Kasey Catalfomo Jan 2016

Automated Image Analysis And Spatial Computational Modeling Of Nf-Kb In Cerebrovascular Endothelial Cells, Kasey Catalfomo

Theses and Dissertations

Cerebrovascular endothelial cells play a key part in the inflammatory response of the blood-brain barrier in pathological conditions such as Alzheimer’s disease. Specifically, the NF-κB signaling pathway plays a central role. Better understanding of the factors in inflammatory disease progression can lead to more effective treatments for such devastating illnesses like Alzheimer’s, asthma, arthritis, cancer, diabetes and many more inflammatory diseases. The proposed approach analyzes spatial NF-κB distribution contained in multispectral stacked micrograph images of cerebrovascular endothelial cells indexed based on dose of the activating protein and the length of activation. Image analysis code identifies the location of ...


A Mechanical Approach To The Characterization Of Material Failure Of Atherosclerotic Lesions, Lindsey A. Davis Jan 2016

A Mechanical Approach To The Characterization Of Material Failure Of Atherosclerotic Lesions, Lindsey A. Davis

Theses and Dissertations

Failure of atherosclerotic plaques can lead to potentially life threatening clinical events such as myocardial infarction (MI), stroke, or transient ischemic attack (TIA). The most frequently described plaque failure mechanism is tensile rupture of the fibrous cap; however, often during angioplasty another plaque failure mechanism occurs in which the atherosclerotic plaque separates from the internal elastic lamina (IEL). This study aims assess the material strength of atherosclerotic lesions using mechanical concepts.

To assess likelihood of plaque dissection at the vessel wall, adhesion strength was assessed in both mouse and human specimens using plaque delamination experiments. Measuring plaque adhesion in transgenic ...


Therapeutic Potential Of Catechins And Derivatives For The Prevention Of Alzheimer’S Disease, Shelby Elaine Chastain Jan 2016

Therapeutic Potential Of Catechins And Derivatives For The Prevention Of Alzheimer’S Disease, Shelby Elaine Chastain

Theses and Dissertations

Alzheimer’s disease (AD) is a neurodegenerative condition that affects 1 in 9 people over the age of 65, an estimated 5.4 million Americans. It is the only disease among the top 10 that cannot be prevented, cured, or treated. Based on the lack of a viable therapeutic for the prevention or cure of AD, it is vital that therapeutic research for AD continues. AD is characterized by the deposition of extracellular neuritic plaques comprised of insoluble amyloid-β (Aβ) fibrils. These plaques are formed from the amyloidogenic aggregation of Aβ monomer, generated from the cleavage of the amyloid precursor ...


A Theoretical Study Of Polymer Based Drug Delivery Systems, Ebtisam Abdullatif Aldaais Jan 2016

A Theoretical Study Of Polymer Based Drug Delivery Systems, Ebtisam Abdullatif Aldaais

Theses and Dissertations

Polymer nanostructured materials for drug delivery applications have witnessed tremendous progress in recent years due to their vast potential. One-end-grafted polymers can form grafted micelles with specific mechanical properties. Biological conditions can alter these properties resulting in the protection or release of drugs. Charged surfactants can also form micelles in an aqueous solution, which can also be manipulated through special conditions. On the micellar surface, self-organized polyelectrolytes can be stimulated to extend their attached ligands and thus increase the probability of binding to targeted receptors. This thesis focuses on modeling polymer-based drug delivery systems by studying the physical interactions between ...