Engineering Commons^™

Development Of A Multispectral Vis-Swir Imaging Modality For Cutaneous Water Assessment, Quinlan Mcgrath

McKelvey School of Engineering Theses & Dissertations

Inflammatory skin diseases are estimated to impact 20% of the global population and are the fourth leading cause of nonfatal disability worldwide. Diagnosis and management are predominantly based on clinician visual assessment of disease related changes in skin morphology. The qualitative nature of this method can result in misdiagnosis and underdiagnoses of treatable diseases. There persists systematic undertreatment of skin of color patients given the more subtle presentation of erythema against pigmented skin. There exists a clinical need for a quantitative and objective inflammation assessment tool that meets the needs of a diverse patient population. The accumulation of interstitial fluid …

Dual Color Optogenetic Control For Analyzing Cardiac Function In Drosophila, Jiantao Zhu

McKelvey School of Engineering Theses & Dissertations

Prolonged consumption of carbohydrate-rich diets and immobile lifestyles frequently cause metabolic disorders and obesity and, as a result, may lead to progressive heart dysfunction among broad social groups of the population. Drosophila melanogaster serves as an essential model organism in cardiovascular disease research due to conserved physiological and genomic traits shared with humans, its genetic and molecular toolbox versatility, and cost-effective maintenance. Here, we combine optogenetics and optical coherence tomography to study cardiovascular function in D. melanogaster. A new optogenetic pacing system has been developed, employing a transgenic line carrying two opsins: ChR2 and NpHR2.0. A custom-built hardware setup …

Pathformer: Interpretable And Powerful Graph Transformer For Gene Network Analysis, Qihang Zhao, Zehao Dong, Muhan Zhang, Philip Payne, Michael Province, Carlos Cruchaga, Tianyu Zhao, Yixin Chen, Fuhai Li

McKelvey School of Engineering Theses & Dissertations

Understanding which gene/pathway expression profiles are related to specific disease phenotypes has been a critical active research area in Bioinformatics. Although graph neural networks (GNNs) have achieved impressive performance on various graph-based real-world applications such as recommendation systems and social network analysis, applying GNNs in gene-network-based Bioinformatical tasks is still challenging due to the effectiveness issue and lack of interpretation methods. In this paper, we propose PathFormer, an interpretable graph Transformer (i.e. GNN), to effectively analyze gene networks and discover meaningful biomarkers/pathways. PathFormer is composed of a stack of PathFormer encoder layers and two subsequent interpretation machines. The PathFormer encoder …

A Novel Mrna Delivery Strategy Employing Adenovirus Piggyback Mrna Binders Via Catcher/Tag Molecular Glue, Kexin Geng

McKelvey School of Engineering Theses & Dissertations

mRNA-based therapeutics open a new era for the prevention and treatment of a wide range of diseases. However, existing mRNA delivery vehicles have limited repertoires for dendritic cell targeting and intranasal administration which are two paramount delivery pathways of significant advantages for treating cancer and infectious respiratory diseases. Adenovirus (Ad) with well-deciphered viral genomes and intensive-studied structure biology has been developed for DCs-targeted cancer vaccines and intranasal COVID vaccines. In light of these virtues, Ad presents as the “off-the-shelf” tool possessing well-defined manufacturable capabilities and translatable feasibility that perfectly complements the current limitations of mRNA delivery. In this study, we …

3-Dimensional Visualization Of Cardiac Plaque Mapping Data, Phan Ly Vy Nguyen

McKelvey School of Engineering Theses & Dissertations

Atrial Fibrillation (AF) of one of the most prevalent cardiac arrythmia in humans, and also the most studied arrythmias due to its high association with cardiovascular morbidity and mortality. Diagnosis of AF, which is highly dependent on the observation of the irregular signal in the atria, is often challenging since AF is often asymptomatic at the onset. There has been a lot of effort in exploring different cardiac mapping techniques to understand the dynamics of AF for better intervention. This study aims at developing a MATLAB interface that assists the development of a cardiac plaque mapping data acquisition system in …

Confined Growth Of Perovskite Stabilized By Strain Engineering, Xucheng Tao

McKelvey School of Engineering Theses & Dissertations

Halide perovskite has been extensively studied for its excellent optoelectronic properties. In this project, we want to explore some range of band gap that conventional 2D materials could not have. To overcome this challenge, we aimed to produce two-dimensional (2D) perovskites with large scale which is suitable for device fabrication and improve its stability using strain engineering. To prepare such 2D perovskite, we tried 2D transformation first and then decided to use confined growth to optimize result. For strain engineering, we employed sputtered nickel as an external stressor.

So far, we have produced multilayer polycrystalline perovskites material close to atomic …

Preparing Non-Human Primates To Study Hand-Eye Coordination In Frontal Eye Fields (Fef) During Delayed Movement Task, Juliusz Cydzik

McKelvey School of Engineering Theses & Dissertations

ABSTRACT OF THE THESIS Preparing Non-Human Primates to Study Hand-Eye Coordination in Frontal Eye Fields (FEF) During Delayed Movement Task by Juliusz Cydzik Master of Science in Biomedical Engineering Washington University in St. Louis, 2023 Professor Lawrence Snyder, Chair Hand-eye coordination enables humans and non-human primates to use their hands and eyes to perform various tasks. We are interested in coordination at the systems level, where saccades and reaches are encoded. The parietal reach region (PRR), situated at the posterior end of the intraparietal sulcus (IPS) and overlapping portions of the medial intraparietal area (MIP) and V6a, is commonly attributed …

Single-Molecule Super-Resolution Imaging Of Geobacter Sulfurreducens Under Anaerobic Conditions, Ziyi Hu

McKelvey School of Engineering Theses & Dissertations

Geobacter sulfurreducens are anaerobic bacteria capable of making electrical contacts with other organisms and extracellular electron acceptors. The challenge of imaging live Geobacter bacteria is maintaining anaerobic conditions during the imaging process. In this thesis, we augment a single-molecule localization microscope (SMLM) with a home-built anaerobic imaging chamber and use constant argon bubbling to maintain oxygen-free imaging conditions. To validate the imaging protocol, we use the transient binding of Nile red to resolve the spherical morphology of lipid-coated glass spheres with nanoscale resolution. However, when imaging Geobacter, the distribution of Nile red localizations is non-uniform, both between different cells …

Development Of Methods To Enhance Stem Cell Derived Islet Survival, Aining Fan

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Synthesis And Characterization Of Sodium Cathode Materials, He Zhou

McKelvey School of Engineering Theses & Dissertations

As sodium batteries hold great promise as a next-generation energy storage device to replace lithium batteries, the development of sodium battery materials has become increasingly urgent. The current study aims to investigate two potential sodium-ion battery cathode materials, Sodium Vanadium Phosphate, and Sodium Manganese Hexacyanoferrate, optimize the experimental procedures, conduct a systematic analysis of material properties and characterization, and ultimately determine the ideal synthesis conditions for these materials.

In the first part of the study, we focused on optimizing the synthesis of Sodium Vanadium Phosphate. By investigating various synthesis conditions, such as annealing temperature, pressure, ascorbic acid content, and material …

Computational Analysis Of Steady Hypersonic Flow Fields Of Nasa Benchmark Geometries Utilizing Ansys Fluent, Aidan Murphy

McKelvey School of Engineering Theses & Dissertations

The Hypersonic International Flight Research Experimentation (HIFiRE) program explores and advances hypersonic aerospace systems by developing a multitude of test flight geometries and conducting experimental test flights to obtain data for use in validation of computational models and results. This study focuses on computational validation of heat flux, and calculation of static pressure profiles, skin friction coefficient profiles, and flow contours. The flow fields studied are for Mach number 7.18 and angles of attack (α) of 0° & 2°. These flow fields include many compressible flow features such as an expansion wave at the intersection of the cone and flat …

Analytical And Experimental Investigation Of Interphase And Dispersion Effects On The Mechanical Stiffness Of Cellulose Nanocomposites, Will Goldberg

McKelvey School of Engineering Theses & Dissertations

The effect of dispersion and interphase properties on the elastic behavior of cellulose nanocomposites was investigated using a number of composite models, experimental data and a thorough literature review. Cellulose nanocomposites consisting of soy protein isolate (SPI) and cellulose nanocrystals (CNC) or polydopamine coated cellulose nanocrystals (PD-CNC) were prepared via solution casting method and tested for mechanical stiffness. These outcomes were compared to standard composite models as well as novel methods adapted from the literature that incorporate data regarding dispersion quality and interphase properties. The literature review verified that both dispersion and interphase properties are highly dependent on interfacial chemistry …

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …

Engineered Material Systems For Mimicking Tissue And Disease, Margrethe Ruding

McKelvey School of Engineering Theses & Dissertations

This thesis comprises two studies involving design and application of soft material systems. The goal of the first study was to design, fabricate, and characterize hydrogel lattice structures with consistent, controllable, anisotropic mechanical properties. Lattices, based on four types of unit cells (cubic, diamond, vintile, and Weaire-Phelan), were printed using stereolithography (SLA) of polyethylene glycol diacrylate (PEGDA). In order to create structural anisotropy in the lattices, unit cell design files were scaled in one direction by a factor of two in each layer and then printed. The mechanical properties of the scaled lattices were measured in shear and compression and …

Persistence Of Dna From Biocontained Genetically Engineered Microbes, Wentao Dai

McKelvey School of Engineering Theses & Dissertations

The utilization of genetically engineered microbes in environmental systems requires effective biocontainment mechanisms to ensure their safe operation. CRISPR-based kill switches are a promising solution, inducing cell death through site-specific DNA cleavage under specific environmental conditions. In this study, we aimed to assess the impact of CRISPR-based kill switches on the abundance and persistence of bacterial DNA. Our results revealed that while CRISPR-based kill switches were capable of achieving high reductions in viable Escherichia coli Nissle 1917 (EcN); the DNA largely remained intact. This was observed in two strains of EcN: one enabled with multi-locus genome cleavage, and the other …

Application Of Direct Simulation Monte Carlo Method To Computation Of Rf Signal Degradation During Hypersonic Flight, Andrew Derubertis

McKelvey School of Engineering Theses & Dissertations

In order to further understand the hypersonic blackout problem, the first step is to investigate models to quantify signal degradation and begin implementing these models to representative plasma sheath and flow data. This research is the first attempt at implementing a model to predict RF signal degradation through the plasma sheath surrounding the hypersonic air vehicle. The investigation is performed using a Direct Simulation Monte Carlo (DSMC) based flow solver. The dsmcFoam solver in the OpenFoam library is used to simulate the flow around hypersonic bodies to obtain flow field properties, most importantly the electron number density profile, to aid …

Comparison Of In-Vitro 3d Human Embryoids With Current Models For Gastrulation, Jin Park

McKelvey School of Engineering Theses & Dissertations

Gastrulation is an early morphogenetic process that is conserved across most metazoans and lays out the future body plan through the formation and shaping of the three germ layers: endoderm, mesoderm, and ectoderm. Despite its importance, not much is known about the events surrounding human gastrulation that occurs in utero due to ethical and technical limitations on studying human embryos. Therefore, many researchers have devised protocols for creating in vitro models of gastrulation using embryonic stem cells. Initially starting with mouse embryonic stem cells, the field of in vitro embryo models has advanced rapidly, with protocols using human embryonic stem …

Effect Of Diabetes-Associated Mutations In Kir 6.2/Sur1 On Katp Channel Activities, Yunpeng Li

McKelvey School of Engineering Theses & Dissertations

Maturity Onset Diabetes of the Young (MODY) is a type of diabetes, distinct from either type I or type II, that happens before age 25 (MedlinePlus, 2022). Unlike the other two more common forms of diabetes, MODY is classified as a series of monogenetic disorders (American Diabetes Association Professional Practice Committee, 2021), caused by autosomal mutations. MODY is typically characterized by insufficient secretion of insulin, a similar symptom to type I diabetes, classified into 14 different types based on mutations found on different genes. Among them, subtypes 12 and 13, also called neonatal diabetes mellitus (NDM), are caused by gain-of-function …

Three-Component Composite Phase-Change Material For Thermal Regulation, Bidisha Ojha

McKelvey School of Engineering Theses & Dissertations

Phase change materials can increase the efficiency of many energy-intensive applications, such as solar power plants, solar heating and cooling systems, heat recovery systems, photovoltaic electricity systems, and Earth satellite systems. In several proposed thermal management systems for high power electronic equipment, PCMs change phase and absorb latent heat at peak energy loads during operation, then dissipate this energy later to prevent overheating. More specifically, composite PCM’s, consisting of an organic material (e.g., paraffin) and an inorganic material (e.g., metallic alloys or salt hydrates), provide a superior balance of thermal conductivity and latent heat for thermal management. Organic PCMs have …

Investigating Applications Of Deep Learning For Diagnosis Of Post Traumatic Elbow Disease, Hugh James

McKelvey School of Engineering Theses & Dissertations

Traumatic events such as dislocation, breaks, and arthritis of musculoskeletal joints can cause the development of post-traumatic joint contracture (PTJC). Clinically, noninvasive techniques such as Magnetic Resonance Imaging (MRI) scans are used to analyze the disease. Such procedures require a patient to sit sedentary for long periods of time and can be expensive as well. Additionally, years of practice and experience are required for clinicians to accurately recognize the diseased anterior capsule region and make an accurate diagnosis. Manual tracing of the anterior capsule is done to help with diagnosis but is subjective and timely. As a result, there is …

Applying Hls To Fpga Data Preprocessing In The Advanced Particle-Astrophysics Telescope, Meagan Konst

McKelvey School of Engineering Theses & Dissertations

The Advanced Particle-astrophysics Telescope (APT) and its preliminary iteration the Antarctic Demonstrator for APT (ADAPT) are highly collaborative projects that seek to capture gamma-ray emissions. Along with dark matter and ultra-heavy cosmic ray nuclei measurements, APT will provide sub-degree localization and polarization measurements for gamma-ray transients. This will allow for devices on Earth to point to the direction from which the gamma-ray transients originated in order to collect additional data. The data collection process is as follows. A scintillation occurs and is detected by the wavelength-shifting fibers. This signal is then read by an ASIC and stored in an ADC …

Optogenetic Heart Pacing And Heart Arrest In Drosophila Melanogaster Using Integrated Ocm Imaging And Light Stimulation System, Yuxuan Wang

McKelvey School of Engineering Theses & Dissertations

Optogenetics has been widely applied to cardiovascular research using different models. Among them, Drosophila melanogaster (fruit fly) outstands for its similarity of human genes for disease modeling and short life cycle for rapid screening to analyze genetic mechanisms of heart disease. However, most of the current models only allow either activation or inhibition of the heartbeat, which is not sufficient to model complex arrhythmia. Our lab developed a novel Drosophila transgenic model based on a double transgenic line containing two light-sensitive genes, Channelrhodopsin-2 (ChR2) and Halorhodopsin2.0 (NpHR2.0), that enable dual-directional control of the heartbeat rhythm. Real-time optical control of the …

Measuring The Effectiveness Of Light Concentration With The Catoptric Surface, Samatha Kodali

McKelvey School of Engineering Theses & Dissertations

The Catoptric Surface is an array of mirrors arranged on the interior of a large window which serves to manipulate the effects of natural lighting inside the room. The framework for moving the mirrors uses an interface which connects various Raspberry Pis and Arduino Unos to move stepper motors that connect to each mirror and move them as desired by the user. This kind of light manipulation allows the atmosphere of the room to be modified using natural lighting rather than artificial lighting and can be useful for varying the way people interact with a space. The intensity at which …

Development Of Optical Coherence Tomography Angiography System For Mouse Eye Imaging And Measurement Of Vasodilation, Yilin Li

McKelvey School of Engineering Theses & Dissertations

Optical coherence tomography angiography (OCTA) is broadly known as a non-invasive technology that allows examining the retinal and choroidal vasculatures, alternative to fluorescein angiography. In this study, we have developed an optical coherence tomography (OCT) system for imaging the mouse eye. We measure the retinal thickness, which is 216.53um. We apply OCTA to characterize the quantitative change in vessel diameter and the perfusion density of the retina after the wild-type mice are administered the adenosine or inhale carbon dioxide. Comparing the images acquired one minute and 5 minutes after the injection or CO₂ inhalation with the baseline, distinct changes …

Computational Fluid Dynamics Modeling Of Hemodialysis In Patients With An Arteriovenous Fistula, Maximilian Roth

McKelvey School of Engineering Theses & Dissertations

With the advent of arteriovenous fistula (AVF) for use in hemodialysis, the anastomosis built for such use has become a central point of the study to understand the flow and wall shear stresses in such a system since very large wall shear stresses can lead to arterial/vein rupture. Considering the commonly used creation site of an anastomosis as connecting the radial artery to the cephalic vein, a model is created to calculate the wall shear stresses across various components of the system. The model depicts a connection of the specified vein and artery bridged together allowing the increase in blood …

The Influence Of Electrical Stimulation Pulse Frequency Of Macro-Sieve Electrode On Rat Sciatic Nerve Detection Threshold, Jingyuan Zhang

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Validation And Verification Of The Wray-Agarwal Turbulence And Algebraic Transition Models For 2d External Airfoil Flows, Dean Ryan-Simmons

McKelvey School of Engineering Theses & Dissertations

Validation and verification benchmark test cases are employed in computational fluid dynamics (CFD) to determine the best practices in application of various CFD tools. These cases focus on the geometry modeling, mesh generation, numerical algorithms, and turbulence models to ensure consistent and accurate numerical simulation of physical phenomena. Assessing model accuracy is essential to identify areas of improvement in various turbulence models. Flow past several symmetric NACA airfoils, namely NACA 0012, NACA 0015 and NACA 0018 are standard test cases for validating and evaluating turbulence models’ accuracy since the experimental data is available for these airfoils. Available wind tunnel data …

Speeding Up The Quantification Of Contrast Sensitivity Functions Using Multidimensional Bayesian Active Learning, Shohaib Shaffiey

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Parametric Design Of A Manifold For A Hollow Micropillar Evaporator For Use In High Heat Flux Applications, Alex Dutton

McKelvey School of Engineering Theses & Dissertations

With the failure of Dennard Scaling and changes in electronics packaging leading toward 2.5 and 3D packages, the current methods of thermal management are failing to keep up with rising heat fluxes. In order to manage these rising heat fluxes, engineers and scientists are looking towards two phase cooling and microchannel flows.

Many forms of novel thermal management are currently being investigated as means to address the thermal challenges present in modern microelectronics, including flow boiling, pool boiling, and direct liquid cooling. One technology of interest is evaporative cooling using continuously fed micro-droplets. High evaporation rates can be achieved by …

Modeling Solvent Extraction Of Lignin From Hardwoods, Su Pan

McKelvey School of Engineering Theses & Dissertations

This study interprets the observed behavior of solvent extraction of lignin from hardwoods by adapting the framework of the FLASHCHAIN theory (Niksa and Kerstein, 1991; Niksa, 2017). A constitution submodel specifies distributions of molecular weight and reactive sites for native lignin. The model simulates delignification as depolymerization of lignin macromolecules into fragments small enough to be soluble. This process competes with intrachain condensation that consumes labile bridges without forming new fragments, and with recombination that forms larger chains and inhibits further depolymerization. After the soluble fragments are transported from the particle into the bulk solvent, all chemistry continues as long …