Biomedical Engineering and Bioengineering Commons^™

Evaluation Of Cell Concentration And Viability By Impedance Spectroscopy On Microfluidic Devices, Jason Eades

LSU Master's Theses

This document describes two distinct platforms that implement electrochemical impedance spectroscopy (EIS) within microfluidic devices for rapid, label-free cell analysis. Each study provides proof-of-concept evaluations of these devices for cell counting and viability analysis applications to mitigate some of the challenges associated with conventional methods. Chapter one includes background information on each version of EIS selected and motivations for the studies conducted. Chapter two describes the design and fabrication of a modular, reusable microfluidic device. Additionally, the methodology for and results from the application of this platform for the measurement of zebrafish sperm cell concentrations are presented. Chapter three describes …

Evaluating Stem Course Re-Design Strategies In Light Of Covid-19, Ulises Juan Trujillo Garcia, Krishna Pakala, Samantha Schauer, Diana Bairaktarova, Bhaskar Chittoori

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The COVID-19 pandemic brought on unprecedented challenges to the teaching and learning communities that required faculty to make purposeful changes in their teaching approaches. Many faculty members had to shift rapidly from in-person to online mode of instruction. This study documents perceptions of STEM faculty who made the change to online teaching. It reports on what strategies faculty used to transition to remote/online teaching and how this change impacted student learning. The study results indicated that almost two-thirds of the faculty changed how they evaluated their students. Results also showed that the sudden change to remote learning negatively impacted student …

A Systematic Review And Meta-Analysis On The Efficacy Of Stem Cell Therapy On Bone Brittleness In Mouse Models Of Osteogenesis Imperfecta, Lauren Battle, Shoshana Yakar, Alessandra Carriero

Publications and Research

There is no cure for osteogenesis imperfecta (OI), and current treatments can only partially correct the bone phenotype. Stem cell therapy holds potential to improve bone quality and quantity in OI. Here, we conduct a systematic review and meta-analysis of published studies to investigate the efficacy of stem cell therapy to rescue bone brittleness in mouse models of OI. Identified studies included bone marrow, mesenchymal stem cells, and human fetal stem cells. Effect size of fracture incidence, maximum load, stiffness, cortical thickness, bone volume fraction, and raw engraftment rates were pooled in a random-effects meta-analysis. Cell type, cell number, injection …

Optimization Of Mechanical Properties At The Infarct Border Zone, Kaushik Sunder

LSU Master's Theses

A myocardial infarction (MI) occurs every 39 seconds in the United States. As of 2016, an estimated 550,000 new and 200,000 recurrent episodes of myocardial infarction (MI) occur each year in the United States was. Infarction is often distinguished by a considerable decrease in wall thickness and an increase in heart size or left ventricular volume. This behavior happens when there is a prolonged lack of blood flow, usually due to damage or clotting, which causes cardiomyocytes to die (CMs). The development of non-contractile infarct scarring is the primary pathophysiology of MI. While the infarct scar prevents myocardial rupture during …

Kinematic Analysis Of Gait In An Underwater Treadmill Using Land-Based Vicon T 40s Motion Capture Cameras Arranged Externally, Shreyas L. Raghu, Ryan T. Conners, Chang-Kwon Kang, David B. Landrum, Paul N. Whitehead

PRC-Affiliated Research

Aquatic therapy for rehabilitation can be performed in a variety of environments, which can vary from a traditional swimming pool to a self-contained underwater treadmill. While kinematic analysis has been performed in large volume swimming pools using specific underwater motion capture systems, researchers may only have access to a land-based motion-capture system, which is not waterproof. Additionally, underwater motion capture systems may not fit within the confines of a smaller underwater treadmill. Thus, the purpose of this study was to design and analyze methodology to quantify lower limb kinematics during an aquatic treadmill session, using a land-based motion capture system. …

Kinematic Analysis Of Gait In An Underwater Treadmill Using Land-Based Vicon T 40s Motion Capture Cameras Arranged Externally, Shreyas L. Raghu, Ryan T. Conners, Chang-Kwon Kang, David B. Landrum, Paul N. Whitehead

PRC-Affiliated Research

Aquatic therapy for rehabilitation can be performed in a variety of environments, which can vary from a traditional swimming pool to a self-contained underwater treadmill. While kinematic analysis has been performed in large volume swimming pools using specific underwater motion capture systems, researchers may only have access to a land-based motion-capture system, which is not waterproof. Additionally, underwater motion capture systems may not fit within the confines of a smaller underwater treadmill. Thus, the purpose of this study was to design and analyze methodology to quantify lower limb kinematics during an aquatic treadmill session, using a land-based motion capture system. …

Th2/Th1 Cytokine Imbalance Is Associated With Higher Covid-19 Risk Mortality, Ana B. Pavel, Jacob W. Glickman, James R. Michels, Seunghee Kim-Schulze, Rachel L. Miller, Emma Guttman-Yassky

Faculty and Student Publications

A major component of COVID-19 severe respiratory syndrome is the patient’s immune response to the SARS-CoV-2 virus and the consequential multi-organ inflammatory response. Several studies suggested a potential role of CD4+ T cells in COVID-19 severe respiratory syndrome. We first hypothesized that there is a type 2 helper (Th2)/type 1 helper (Th1) imbalance in older age, male, asthma, smokers, and high ACE2 expression phenotype in the airway of non-infected patients. Next, we hypothesized that a Th2/Th1 imbalance may predict higher mortality in COVID-19 infected hospitalized patients with and without patient reported current asthma. We first analyzed publicly available gene expression …

Computational Investigation Of Biological Membranes, Allyson Karmazyn

Theses - ALL

Lipids are the building blocks of biological membranes, and the types of lipids that compose these cellular envelopes influence the physicochemical properties of the chemicals that can enter or exit the cell across the membrane. This work focuses on the lipid membrane compositions of eukaryotic (red blood cells) and prokaryotic (Pseudomonas aeruginosa) membranes. By analyzing the lipid-lipid and lipid-protein interactions results of the computational simulations, insights into lipid aggregation, bilayer leaflet behavior, membrane asymmetry, and small molecule transport through protein channels were obtained. The differences between prokaryotic and eukaryotic cell membranes are qualitative known; however, this work provides these concepts …

Optical Printing Of Multiscale Hydrogel Structures, Zheng Xiong

Dissertations - ALL

Hydrogel has been a promising candidate to recapitulate the chemical, physical and mechanical properties of natural extracellular matrix (ECM), and they have been widely used for tissue engineering, lab on a chip and biophotonics applications. A range of optical fabrication technologies such as photolithography, digital projection stereolithography and laser direct writing have been used to shape hydrogels into structurally complex functional devices and constructs. However, it is still greatly challenging for researchers to design and fabricate multiscale hydrogel structures using a single fabrication technology.

To address this challenge, the goal of this work is the design and develop novel multimode …

The Development Of An Instrument To Measure Transdermal Hydrogen Sulfide As A Way To Evaluate Microvascular Health In Humans, Benjamin Thomas Matheson

Biomedical Engineering ETDs

Hydrogen sulfide (H₂S) is a gasotransmitter critical in maintaining microcirculation homeostasis. Impaired microcirculation occurs in multiple disease states such as peripheral vascular disease, diabetes mellitus (DM), and hypertension. Early detection and identification of patients with DM who are at risk for heart attack, stroke and amputation due to microvascular disease is crucial. Human skin is an accessible vascular bed that provides an opportunity to non-invasively measure H₂S, which could be used as a biomarker to evaluate microvascular health.

In this work, a novel H₂S gas sensor, called the transdermal arterial gasotransmitter sensor (TAGS^{TM …}

Pathcnn: Interpretable Convolutional Neural Networks For Survival Prediction And Pathway Analysis Applied To Glioblastoma, Jung Hun Oh, Wookjin Choi, Euiseong Ko, Mingon Kang, Allen Tannenbaum, Joseph O. Deasy

Computer Science Faculty Research

Motivation: Convolutional neural networks (CNNs) have achieved great success in the areas of image processing and computer vision, handling grid-structured inputs and efficiently capturing local dependencies through multiple levels of abstraction. However, a lack of interpretability remains a key barrier to the adoption of deep neural networks, particularly in predictive modeling of disease outcomes. Moreover, because biological array data are generally represented in a non-grid structured format, CNNs cannot be applied directly. Results: To address these issues, we propose a novel method, called PathCNN, that constructs an interpretable CNN model on integrated multi-omics data using a newly defined pathway image. …

Correlating Diffusional Dynamics And Receptor Tyrosine Kinase Function Using Single Quantum Dot Tracking, Irais Ortiz Caraveo

Biomedical Engineering ETDs

Epidermal growth factor receptor (EGFR) signal transduction is initiated via ligand (EGF) binding, followed by dimerization, autophosphorylation of the C-terminal tails, and recruitment of proteins that form a larger signaling complex to propagate the signal. We explored the relationship between receptor mobility and signaling using single-particle tracking (SPT) by examining the diffusional dynamics of EGFR and two truncation mutants to understand whether mobility changes are correlated with signaling. Results revealed that phosphorylation of the C-terminal tail of EGFR is required for maximal reduction in mobility that occurs with EGF stimulation, indicating that receptor mobility is a read-out for receptor signaling. …

Mutational Analysis Of Latency Associated Peptide For Therapeutic Application, Johnny Will Stephens

USF Tampa Graduate Theses and Dissertations

TGF-β is an important protein for regulation of the immune system, and has been linked to promotion of tumor progression and cancer growth. Inhibiting TGF-β has been shown to be an effective therapeutic technique for fighting multiple cancer types. Engineering TGF-β’s natural inhibitor, Latency Associated Peptide (LAP), to improve its biophysical properties has potential to increase therapeutic efficacy.

Rosetta and FoldX can be used in concert to engineer stabilizing mutations of proteins. In accordance with this, PyRosetta and FoldX were used to predict stabilizing mutations of LAP. The most stabilizing mutations from each program were combined with mutually predicted mutations. …

Acute Effect Of High‑Definition And Conventional Tdcs On Exercise Performance And Psychophysiological Responses In Endurance Athletes: A Randomized Controlled Trial, Daniel Gomes Da Silva Machado, Marom Bikson, Abhishek Datta, Egas Caparelli‑Dáquer, Gozde Unal, Abrahão F. Baptista, Edilson Serpeloni Cyrino, Li Min Li, Edgard Morya, Alexandre Moreira, Alexandre Hideki Okano

Publications and Research

Transcranial direct current stimulation (tDCS) has been used aiming to boost exercise performance and inconsistent findings have been reported. One possible explanation is related to the limitations of the so-called “conventional” tDCS, which uses large rectangular electrodes, resulting in a diffuse electric field. A new tDCS technique called high-definition tDCS (HD-tDCS) has been recently developed. HD-tDCS uses small ring electrodes and produces improved focality and greater magnitude of its aftereffects. This study tested whether HD-tDCS would improve exercise performance to a greater extent than conventional tDCS. Twelve endurance athletes (29.4 ± 7.3 years; 60.15 ± 5.09 ml kg− 1 min− …

Nanoparticles For Targeted Drug Delivery To Cancer Stem Cells: A Review Of Recent Advances, Yavuz Nuri Ertas, Keyvan Abedi Dorcheh, Ali Akbari, Esmaiel Jabbari

Faculty Publications

Cancer stem cells (CSCs) are a subpopulation of cells that can initiate, self-renew, and sustain tumor growth. CSCs are responsible for tumor metastasis, recurrence, and drug resistance in cancer therapy. CSCs reside within a niche maintained by multiple unique factors in the microenvironment. These factors include hypoxia, excessive levels of angiogenesis, a change of mitochondrial activity from aerobic aspiration to aerobic glycolysis, an upregulated expression of CSC biomarkers and stem cell signaling, and an elevated synthesis of the cytochromes P450 family of enzymes responsible for drug clearance. Antibodies and ligands targeting the unique factors that maintain the niche are utilized …

Traveling Wave Solutions For Two Species Competitive Chemotaxis Systems, T. B. Issa, R. B. Salako, W. Shen

Faculty Research, Scholarly, and Creative Activity

In this paper, we consider two species chemotaxis systems with Lotka–Volterra competition reaction terms. Under appropriate conditions on the parameters in such a system, we establish the existence of traveling wave solutions of the system connecting two spatially homogeneous equilibrium solutions with wave speed greater than some critical number c∗. We also show the non-existence of such traveling waves with speed less than some critical number c∗0 , which is independent of the chemotaxis. Moreover, under suitable hypotheses on the coefficients of the reaction terms, we obtain explicit range for the chemotaxis sensitivity coefficients ensuring c∗ = c∗0 , which …

Centralized And Decentralized Optimal Control Of Variable Speed Heat Pumps, Ryan S. Montrose, John F. Gardner, Aykut C. Satici

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Utility service providers are often challenged with the synchronization of thermostatically controlled loads. Load synchronization, as a result of naturally occurring and demand-response events, has the potential to damage power distribution equipment. Because thermostatically controlled loads constitute most of the power consumed by the grid at any given time, the proper control of such devices can lead to significant energy savings and improved grid stability. The contribution of this paper is the development of an optimal control algorithm for commonly used variable speed heat pumps. By means of selective peer-to-peer communication, our control architecture allows for the regulation of home …

Rapid Microscopic Fractional Anisotropy Imaging Via An Optimized Linear Regression Formulation., N J J Arezza, D H Y Tse, C A Baron

Medical Biophysics Publications

Water diffusion anisotropy in the human brain is affected by disease, trauma, and development. Microscopic fractional anisotropy (μFA) is a diffusion MRI (dMRI) metric that can quantify water diffusion anisotropy independent of neuron fiber orientation dispersion. However, there are several different techniques to estimate μFA and few have demonstrated full brain imaging capabilities within clinically viable scan times and resolutions. Here, we present an optimized spherical tensor encoding (STE) technique to acquire μFA directly from the 2nd order cumulant expansion of the powder averaged dMRI signal obtained from direct linear regression (i.e. diffusion kurtosis) which requires fewer powder-averaged signals than …

Influence Of Extracellular Matrix Stiffness And Topography On Neuronal Cell Behavior And Neurite Outgrowth, Mohan Yasodharababu

Graduate Theses and Dissertations

The focus of regeneration therapy for traumatic brain injuries and Alzheimer's disease is on the promotion and growth of neuronal cells. In vitro research attempts to improve this by modifying the stiffness and topography of the extracellular matrix (ECM). However, the limitations of in vitro experiments make it difficult to control the individual factors influencing neuronal cell growth. A computational model can be used to decouple individual factors and study them individually to gain a better understanding of the mechanics between the neuronal cell and ECM, which will aid in the design of in vitro experimental studies.

This study develops …

Regulation Of Inflammatory Processes By Tryptamine, Cannabidiol And 2,3,7,8-Tetrachlorodibenzo-P-Dioxin, Nicholas Dopkins

Theses and Dissertations

Host immunity is a complicated system of pro-inflammatory and anti-inflammatory processes that respond to exogenous and endogenous threats to regulate host physiology, inhibit carcinogenesis, and protect from infections. Sustained deviance from normal immunological function occurs due to a variety of factors both endogenous and exogenous, with some factors that can dysregulate host immunity including: genetics, microbiota composition, toxin exposure, age, gender, and smoking. The etiology of inflammatory disorders is both convoluted and complex due to the sheer number of facets regulating host immunity. To better contribute to understanding how immunological dysregulation occurs we focused on how three anti-inflammatory compounds (tryptamine, …