Biomedical Engineering and Bioengineering Commons^™

Synthesis Of A Series Of Trimeric Branched Glycoconjugates And Their Applications For Supramolecular Gels And Catalysis, Jonathan Bietsch, Anji Chen, Dan Wang, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-derived molecular gelators have found many practical applications as soft materials. To better understand the structure and molecular gelation relationship and further explore the applications of sugar-based gelators, we designed and synthesized eight trimeric branched sugar triazole derivatives and studied their self-assembling properties. These included glucose, glucosamine, galactose, and maltose derivatives. Interestingly, the gelation properties of these compounds exhibited correlations with the peripheral sugar structures. The maltose derivative did not form gels in the tested solvents, but all other compounds exhibited gelation properties in at least one of the solvents. Glucose derivatives showed superior performance, followed by glucosamine derivatives. They …

Biom 3010: Medical Measurements (Syllabus), Carl D. Herickhoff

Biomedical Engineering Syllabi Archive

Course Description: Theory and application of major types of sensors used in biomedical engineering and clinical medicine; principles of signal processing and instrumentation, such as frequency domain analysis, operational amplifiers, and filtration.

Defining Sagittal Plane Gait Mechanics And Joint Loading In People With Marfan Syndrome, Justin Melan Pol

Theses and Dissertations--Biomedical Engineering

Marfan syndrome (MFS) is a genetic condition that is associated with altered muscle composition, which leads to muscle dysfunction. People with MFS exhibit high instances of lower extremity (LE) joint pain that inhibits their ability to perform activities of daily living, such as walking. Despite these detrimental impacts of MFS, there have been no attempts to characterize the effects of MFS on LE joint loading and health during walking that are associated with LE pain and dysfunction. As people with MFS exhibit a high incidence rate of osteoarthritis (OA), the need to understand the potential alterations in LE extremity mechanics …

3-Dimensional Muscle Constructs: Using Hydrogels In Order To Model The Effects Of Exercise In Disease Conditions, Mark Mchargue

Theses and Dissertations--Biomedical Engineering

Currently, there is no standard in vitro model for studying the effects of mechanical stimulation on muscle in type II diabetes. Existing models primarily utilize electrical stimulation, which does not fully recapitulate the effects of exercise. In this thesis, we create a standardized in vitro model of murine muscle that can recapitulate the benefits seen in exercise when mechanically stimulated. Moreover, we show that a type II diabetes environment has similar effects on the muscle in vitro as well as in vivo.

Multiscale And Multimodality Optical Imaging Of Brain Hemodynamics And Function, Mehrana Mohtasebi

Theses and Dissertations--Biomedical Engineering

Frequent measurement of cerebral hemodynamics is crucial for continuous assessment of brain function and health. Low-frequency oscillations (LFOs; < 0.1 Hz) have shown promise as an indicator of altered neurologic activity in the abnormal brain. Moreover, quantification of temporal correlations in LFOs across distinct brain regions enables mapping of regional neurovascular disorders. Portable diffuse optical techniques such as near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS) enable noninvasive and continuous measurements of cerebral oxygenation and cerebral blood flow (CBF), respectively. However, most NIRS/DCS systems use limited numbers of discrete light sources and detectors and thus lack combinations of high temporal/spatial resolution and large field-of-view (FOV) for brain imaging. Recent development of an innovative noncontact speckle contrast diffuse correlation tomography (scDCT) in our lab provides a low-cost and portable tool for high-density imaging of CBF distributions over large FOVs. The scDCT uses a galvo-mirror to remotely deliver coherent point near-infrared light to multiple source positions and a CMOS camera as a high-density 2-D detector array to quantify spatial fluctuations of diffuse laser speckles, resulting from movement of red blood cells. Boundary CBF data were input to a unique finite-element-method (FEM)-based reconstruction algorithm for 3-D imaging of CBF distributions. However, scDCT was hindered for extracting LFOs due to its low sampling rate. In this study, scDCT was optimized to achieve high sampling rates and fast image reconstructions by use of moving window algorithms with parallel computations (Project 1). Power spectral density (PSD) analysis was performed to investigate altered LFOs during transient cerebral ischemia in neonatal piglets. Transient cerebral ischemia caused reductions in both CBF and PSD, supporting inclusion of scDCT in the growing field of LFO analysis. One remaining limitation was the long computational time required for 3-D reconstruction, which prohibited real-time applications. To overcome this limitation, a depth-sensitive diffuse speckle contrast topography (DSCT) method was developed for analyzing scDCT data to achieve fast and high-density 2-D mapping of CBF distribution without the need of complex and time-consuming 3-D reconstructions (Project 2). New head-simulating phantoms with known optical/geometric properties were designed and fabricated to evaluate the spatial resolution and depth sensitivity of DSCT method. In-vivo experiments verified the capability of DSCT in tracking dynamic changes in CBF at different depths during CO₂ inhalation and transient cerebral ischemia in rats. In addition to preclinical studies, a low-cost, wearable, fluorescence eye loupe (FLoupe) device was invented for intraoperative visualization of brain tumor margin in the clinic (Project 3). Consistent results were observed against an expensive, large, standard fluorescence operative microscope for the guidance of tumor resection. Overall, through 3 projects this dissertation demonstrated a variety of noninvasive noncontact optical technologies (scDCT, DSCT, and FLoupe) that enabled multiscale (rodents, piglets, and humans) and …

A Wearable Fiber-Free Optical Sensor For Continuous Measurements Of Cerebral Blood Flow And Oxygenation, Xuhui Liu

Theses and Dissertations--Biomedical Engineering

Wearable technologies for continuous monitoring of cerebral hemodynamics in freely behaving subjects not only advance our understanding of cognitive processing and adaptive behavior, but also provide vital information for diagnosis and therapeutic assessment of cerebral diseases associated with hypoxia/ischemia. Wearable near-infrared diffuse optical techniques have been used at the bedside to probe deep cerebral hemodynamics, including near-infrared spectroscopy (NIRS) for cerebral oxygenation measurement and diffuse correlation spectroscopy (DCS) for cerebral blood flow (CBF) measurement, respectively. However, most systems are relatively large and expensive, and use rigid fiber-optic probes that significantly constrain subject’s movement. A novel, wearable, fiber-free diffuse speckle contrast …

Microalgae Immobilization With Filamentous Fungi: Process Development For Sustainable Food Systems, Suvro Talukdar

Theses and Dissertations--Biosystems and Agricultural Engineering

Demand for sustainable food sources has increased because of the rapid growth of the world's population.  In this study, microalgae cells of Haematococcus pluvialis were immobilized using the edible fungal strain Aspergillus awamori for potential food applications. The study investigated the impact of fungal loading, pellet geometry, and initial microalgae cell concentration on the immobilization performance and product characteristics. It was found that higher fungal loading and larger fungal pellets contributed to increased immobilization performance while increased initial microalgae concentration inhibited the process. Larger fungal pellets had decreased biomass density, which led to decreased surface concentration of immobilized microalgae but …

Evaluation Of Cold Atmospheric Plasma For The Decontamination Of Flexible Endoscopes, R. C. Hervé, Michael G. Kong, Sudhir Bhatt, Hai-Lan Chen, E. E. Comoy, J-P. Deslys, T. J. Secker, C. W. Keevil

Bioelectrics Publications

Background: Despite adherence to standard protocols, residues including live microorganisms may remain on the various surfaces of reprocessed flexible endoscopes. Prions are infectious proteins notoriously difficult to eliminate.

Aim: We tested the potential of cold atmospheric plasma (CAP) for the decontamination of flexible endoscope various surfaces, measuring total proteins and prion-residual infectivity as an indicator of efficacy.

Methods: New PTFE endoscope channels and metal test surfaces spiked with test soil or prion-infected tissues were treated using different CAP-generating prototypes. Surfaces were then examined for the presence of residues using very sensitive fluorescence epi-microscopy. Prion residual infectivity was determined using the …

Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar

Chemistry & Biochemistry Faculty Publications

Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg …

Life Cycle Assessment Of Air Classification As A Sulfur Mitigation Technology In Pine Residue Feedstocks, Ashlee Edmonson

Theses and Dissertations--Biosystems and Agricultural Engineering

Sulfur accumulation during biofuel production is pollutive, toxic to conversion catalysts, and causes the premature breakdown of processing equipment. Air classification is an effective preprocessing technology for ash and sulfur removal from biomass feedstocks. A life cycle assessment (LCA) sought to understand the environmental impacts of implementing air classification as a sulfur-mitigation technique for pine residues. Energy demand and material balance for preprocessing were simulated using SimaPro and the Argonne National Laboratory’s GREET model, specifically focusing on comparing the global warming potential (GWP) of grid electricity versus bioelectricity scenarios. Overall, the grid electricity scenario had a GWP impact over 7 …

Long-Range Aceo Phenomena In Microfluidic Channel, Diganta Dutta, Keifer Smith, Xavier Palmer

Electrical & Computer Engineering Faculty Publications

Microfluidic devices are increasingly utilized in numerous industries, including that of medicine, for their abilities to pump and mix fluid at a microscale. Within these devices, microchannels paired with microelectrodes enable the mixing and transportation of ionized fluid. The ionization process charges the microchannel and manipulates the fluid with an electric field. Although complex in operation at the microscale, microchannels within microfluidic devices are easy to produce and economical. This paper uses simulations to convey helpful insights into the analysis of electrokinetic microfluidic device phenomena. The simulations in this paper use the Navier–Stokes and Poisson Nernst–Planck equations solved using COMSOL …

An Investigation Of The Effect Of Cyclic Loading Of Bone On Osteocyte Processes Spanning Micro-Cracks As A Driver Of Targeted Remodelling Of Bone, Morgana Pires Afonso Shirsath

Doctoral

Bone remodelling is essential to maintain and improve the quality of bones. This occurs with the action of specialised cells - osteoclasts and osteoblasts - which replace the old bone tissue with new in regions where damage has occurred. Osteocytes are responsible for signalling the presence of damage and trigger the bone remodelling response. According to the Scissors Model, the presence of micro-cracks causes rupture of the osteocyte processes by fatigue because of the repeated stretching resulting from the relative movement of micro-crack faces, when bone is subjected to cyclic loads.

Sodium Hyaluronate Based Drug Delivery To The Outer And Inner Ear, Emma Barrett-Catton

Graduate Student Theses, Dissertations, & Professional Papers

We have developed two projects using sodium hyaluronate (HA)-based systems for drug delivery to the ear. First, we investigated an HA-based hydrogel for use as a single use antibiotic treatment for otitis externa. Otitis externa, also known as outer ear infection, is a frequent affliction in both humans and animals. The most prevalent treatment for otitis externa is ear drops, but it is difficult to adhere properly to this treatment, causing poor patient compliance and the potential for complications. As a result, we have developed an HA-based hydrogel for use as a single application treatment for otitis externa to increase …

Analyzing Physiological Signals During The Menstrual Cycle: Introducing An Application Of Circular Statistics, Krystal D. Sides

UNF Graduate Theses and Dissertations

Physiological signals are used in engineering and the sciences to determine the state of functionality of certain physiological systems such as the human endometrium. Many women use the basal body temperature method to track ovulation, or their fertile window. However, temperature tracking alone is subject to environmental factors. Non-invasive wearable devices can be tools in recording cycle-related physiological features relevant to women’s health research. This research uses the Empatica E4 wristband to track changes in the physiological features during sleep across the menstrual cycle of ovulating and non-ovulating females. Due to the cyclic nature of menstrual cycles, analytic solutions to …

Chronic Anemia Revealing An Idiopathic Watermelon Stomach: Case Report, Hanane Delsa, Imane Rahmouni, Yassamin Benhayoun Sadafyine, Fatima Belabbes, Anass Nadi, Fedoua Rouibaa

Health Sciences

Watermelon stomach, also known as gastric antral vascular ectasia (GAVE) syndrome, is a rare entity. Patients often present with profound unexplained anemia with or without bleeding externalization. We made the diagnosis during a digestive endoscopy for an etiological assessment of this anemia. Endoscopically, antral erythematous lesions in stripes with a punctate appearance, sometimes hemorrhagic, may suggest a watermelon stomach. The pathophysiology of the watermelon stomach remains complex and unclear. Although several pathologies remain implicated, sometimes, it can be idiopathic. The effectiveness of numerous treatments has been evaluated with relatively satisfactory results. This is a rare case of an idiopathic watermelon …

The Strength Of Motivation For Dental Students, Manal Elhijazi, Ihsane Benyahya

Health Sciences

Context: Motivation plays a key role in academic success. It is a dynamic process that maintains perseverance and tenacity in the face of difficulty. The purpose of our study was to measure and compare the strength of dental students' motivation at the beginning and the end of their training Material and methods: an anonymous self-administered voluntary questionnaire was distributed to 1st and 6th year students at the Faculty of Dentistry in Casablanca This questionnaire consisted of 30 closed questions divided into 3 sections, the first of which provided information on socio-demographic data, the second is devoted to measuring the strength …

Reactive Oxygen Species (Ros)-Responsive Size-Reducible Nanoassemblies For Deeper Atherosclerotic Plaque Penetration And Enhanced Macrophage-Targeted Drug Delivery, Jianhua He, Wenli Zhang, Xiaoju Zhou, Fengfei Xu, Jiahui Zou, Qiqi Zhang, Yi Zhao, Hongliang He, Hu Yang, Jianping Liu

Chemical and Biochemical Engineering Faculty Research & Creative Works

Nanoparticle-Based therapeutics represent potential strategies for treating atherosclerosis; however, the complex plaque microenvironment poses a barrier for nanoparticles to target the dysfunctional cells. Here, we report reactive oxygen species (ROS)-responsive and size-reducible nano assemblies, formed by multivalent host-guest interactions between β-cyclodextrins (β-CD)-anchored discoidal recombinant high-density lipoprotein (NP3ST) and hyaluronic acid-ferrocene (HA-Fc) conjugates. the HA-Fc/NP3ST nano assemblies have extended blood circulation time, specifically accumulate in atherosclerotic plaque mediated by the HA receptors CD44 highly expressed in injured endothelium, rapidly disassemble in response to excess ROS in the intimal and release smaller NP3ST, allowing for further plaque penetration, macrophage-targeted cholesterol efflux and …

Development Of A Solution Synthesis Of Poly(Sebacic Anhydride) With The Activating Agent 4-Toluenesulfonyl Chloride: Understanding The Effect Of Different Bases On The Reaction Products, Patricia Poley

Honors Theses

The overall goal of this honors thesis was to develop a solution synthesis of Poly(Sebacic Anhydride) with the activating agent 4-toluenesulfonyl chloride and understand the effects of varying temperature, bases, and the addition order of reagents on the reaction.

Polyanhydrides are a class of hydrophobic, degradable polymers used in controlled drug delivery for 30 years. They are synthesized through three general methods: melt polycondensation, solution polycondensation, and ring-opening polymerization. Of these three methods, solution polycondensation typically results in products with lower molecular weight. Previous work in the Vogel lab identified two new ways to synthesize anhydrides using solution polycondensation reactions …

The Effects Of Dental Hygiene Instrument Handles On Muscle Activity Production, Jessica R. Suedbeck, Daniel Russell, Cortney Armitano Lago, Emily A. Ludwig

Dental Hygiene Faculty Publications

Purpose The objective of this study was to compare the effects of ten commercially available instrument handle designs’ mass and diameter on forearm muscle activity during a simulated periodontal scaling experience.

Methods A convenience sample of 25 registered dental hygienists were recruited for this IRB-approved study. Ten commercially available instruments were categorized into four groups based on their masses and diameters: large diameter/light mass, small diameter/light mass, large diameter/heavy mass, and small diameter/heavy mass. Participants were randomized to four instruments with one from each group. Participants scaled with each instrument in a simulated oral environment while muscle activity was collected …

Exploring Ph Gradient Phenomena In Non-Linear Electrokinetic Microfluidic Devices, Azade Tahmasebi

Dissertations, Master's Theses and Master's Reports

Electrokinetic microfluidics is a versatile technology utilized within lab on a chip (LOC) devices for diagnostic and analytical applications; advantages include reduced resource demands, flexibility, and simplicity of use. Dielectrophoresis (DEP) is a precision nonlinear electrokinetic tool utilized within microfluidic microdevices to induce polarization and control bioparticle motions for applications that range from hemoglobin separations to cancer cell isolation and detection. Despite promising results, undesired side phenomena can occur in electrokinetic systems which impede reproducibility and accuracy. These unfavorable phenomena have not been comprehensively explored in the literature. Prior preliminary research suggests the fundamental phenomena originate from microelectrodes utilized in …

An Acute Respiratory Distress Syndrome Drug Development Collaboration Stimulated By The Virginia Drug Discovery Consortium, John S. Lazo, Ruben M.L. Colunga-Biancatelli, Pavel A. Solopov, John D. Catravas

Bioelectrics Publications

The genesis of most older medicinal agents has generally been empirical. During the past one and a half centuries, at least in the Western countries, discovering and developing drugs has been primarily the domain of pharmaceutical companies largely built upon concepts emerging from organic chemistry. Public sector funding for the discovery of new therapeutics has more recently stimulated local, national, and international groups to band together and focus on new human disease targets and novel treatment approaches. This Perspective describes one contemporary example of a newly formed collaboration that was simulated by a regional drug discovery consortium. University of Virginia, …

Editorial: Pulsed Electric Field Based Technologies For Oncology Applications, Siqi Guo, Gregor Sersa, Richard Heller

Bioelectrics Publications

No abstract provided.

Advancing Medical Technology For Motor Impairment Rehabilitation: Tools, Protocols, And Devices, Matthew Yough

Graduate Theses, Dissertations, and Problem Reports (ETD)

Excellent motor control skills are necessary to live a high-quality life. Activities such as walking, getting dressed, and feeding yourself may seem mundane, but injuries to the neuromuscular system can render these tasks difficult or even impossible to accomplish without assistance. Statistics indicate that well over 100 million people are affected by diseases or injuries, such as stroke, Parkinson’s Disease, Multiple Sclerosis, Cerebral Palsy, peripheral nerve injury, spinal cord injury, and amputation, that negatively impact their motor abilities. This wide array of injuries presents a challenge to the medical field as optimal treatment paradigms are often difficult to implement due …

Longitudinal Oxygen Imaging In 3d (Bio)Printed Models, Ryan Curtis O'Connell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electron paramagnetic resonance (EPR), and its molecular imaging modality, is a powerful tool to noninvasively map various biological and chemical markers within objects of interest. Reliable data acquisition is a major impeding factor for longitudinal hands-off measurements. Measurements are especially challenging in biomedical applications, as live objects are not static. Frequent changes occur that require constant fine recalibration of the EPR detection system, called the resonator. To enable longitudinal imaging, a technology permitting automatic digital control of resonator coupling, tuning, and EPR data acquisition was developed. Automation was achieved through the utilization of a microcontroller and digital peripheral components such …

Advancing Prosthetic Design Using Neural And Mechanical Dynamics, Kacie E. Hanna

Graduate Theses, Dissertations, and Problem Reports (ETD)

Limb loss poses a significant challenge to mobility and the performance of daily activities. Currently, nearly half of the amputees using powered prosthetics abandon their device due to inadequate limb coordination and movement control abilities. In the healthy system, passive and neural dynamics facilitate the synchronized activation of muscles necessary for coordinated movement. However, in the amputee, the system is disrupted. The goal of this research is to use neural and mechanical dynamics to inform the design of prosthetic devices in order to restore intuitive control and coordinated limb movement.

The first aim of this research is to investigate neural …

Evaluation Of Changes In Cellular Behavior Upon Exposure To Selected Analytes Used In Synthetic Applications, Olivia L. Rose

Graduate Theses, Dissertations, and Problem Reports (ETD)

Metal-organic frameworks (MOFs) are organic crystalline hybrids that have been used for a variety of applications from catalysis to gas storage and drug delivery. Studies have shown that generally, while such frameworks are more biocompatible than similar aspect ratio nanostructures, they are also more prone to transformation and disintegration due to their flexible and fragile nature as resulted from the structure assembly and implemented structure-function relationships. With extensive previous literature showing that materials with nano dimensions such as carbon nanotubes, quantum dots and other nanomaterials have unique physicochemical properties that lead to increased biosystems’ reactivity. With increasing concerns regarding adverse …

Impacts Of Diverse Inflammatory Stimuli On Neutrophil Behavior: Extracellular Vesicles, E-Cigarettes, And Nanoparticles, Hunter T. Snoderly

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neutrophils are the body’s front-line defenders against foreign insult and are key players in a variety of inflammatory conditions. This body of work examines the role of neutrophils in promoting pathology in three distinct inflammatory contexts. In the pro-inflammatory state provoked by breast cancer, neutrophils decondense their nuclei and release cytotoxic web-like structures known as neutrophil extracellular traps (NETs). NETs form most commonly via histone modifications facilitated by the enzyme PAD4. NETs are known to be a harbinger of disease progression and promote metastasis through capture of circulating tumor cells. It was hypothesized that breast tumors release small particles known …

Calpains In The Peripheral Nerve And During Demyelination And Degeneration In Rodents, John A. Miller

Browse all Theses and Dissertations

Myelin formed around axons ensures rapid and efficient action potential propagation. Disruption of myelinated axons in the peripheral nervous system (PNS) often causes nerve conduction failure, neurological symptoms and can lead to long-term disability. Calpains are calcium dependent cysteine proteases that play many roles during both normal physiology and pathogenesis. Calpain-1 (CAPN1) and calpain-2 (CAPN2) are key calpain paralogs found in the nervous system and potentially have opposing roles, with CAPN2 having a more neurodegenerative function. In the central nervous system (CNS), calpains have a role in developmental myelination as well as in the pathological demyelination of multiple sclerosis and …

Mouthpiece For Patients With Neuromuscular Disorders, Rebekah Starkey, Carissa Thompson, Michael Dickens, Andrew Pero

Williams Honors College, Honors Research Projects

Neuromuscular Disorders (NMDs) impact people throughout the world. An early hallmark of these disorders includes some degree of facial muscle weakness. Respiratory testing is important to evaluate the progression of these patients’ NMDs. However, these tests require that the patient purses their lips around a mouthpiece to create a tight seal. This is a difficult task for one with facial muscle degeneration. This often leads to results that fail to reflect the patient’s true respiratory ability and prevents their physician from providing the appropriate degree of care. The objective of this project was to develop a face mask or mouthpiece …

Verification Of Proton Range Predictions In Proton Treatment Planning Using X-Ray Ct Or Proton Ct Imaging, Nicholas S. Yee

Graduate Research Theses & Dissertations

The objective of this paper is to compare the range errors for two treatment plans; one using x-ray CT and the other using proton CT for calculating dose distributions in an animal tissue phantom. We shot 150 MeV proton beam through a meat phantom to a film stack to measure the exponential drop of dose at the Bragg peak until zero dose remained. Plotting the depth dose curves and performing gamma analyses are two ways to quantify the proton range errors when comparing them to depth dose curves from film measurements in the phantom. The depth dose curves give us …