Biomedical Engineering and Bioengineering Commons^™

Crystallization Of Community-Acquired Respiratory Distress Syndrome Toxin From Mycoplasma Pneumonia, Olga N. Pakhomova, Alexander B. Taylor, Argentina Becker, Stephen P. Holloway, T. R. Kannan, Joel B. Baseman, P. John Hart

Bioelectrics Publications

Community-acquired respiratory distress syndrome toxin (CARDS TX) is a 591-amino-acid protein with ADP-ribosyltransferase and vacuolating activities that damages the cells lining the respiratory tracts of patients infected with the bacterial pathogen Mycoplasma pneumoniae. Crystals of CARDS TX were grown in space group C2, with unit-cell parameters a = 191.4, b = 107.4, c = 222.1 A, beta = 90.6 degrees. A complete 2.2 A data set was obtained from a single CARDS TX crystal.

Electrically Mediated Delivery Of Plasmid Dna To The Skin, Using A Multielectrode Array, Richard Heller, Yolmari Criz, Loree C. Heller, Richard A. Gilbert, Mark J. Jaroszeski

Bioelectrics Publications

The easy accessibility of skin makes it an excellent target for gene transfer protocols. To take full advantage of skin as a target for gene transfer, it is important to establish an efficient and reproducible delivery system. Electroporation is a strong candidate to meet this delivery criterion. Electroporation of the skin is a simple, direct, in vivo method to deliver genes for therapy. Previously, delivery to the skin was performed by means of applicators with relatively large distances between electrodes, resulting in significant muscle stimulation and pain. These applicators also had limitations in controlling the directionality of the applied field. …

Controlling Nonviral Gene Delivery Through The Cell-Biomaterial Interface, Beth A. Duensing

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Controlling Nonviral Gene Delivery through the Cell-Biomaterial Interface
Beth Ann Duensing, M.S. University of Nebraska, 2010
Adviser: Angela Pannier

Cell-biomaterial interactions and the corresponding cellular behaviors are poorly understood. Therefore, in this study, the ability of biomaterial surface properties to control nonviral gene delivery was investigated through surface chemistry and protein adsorption and subsequently correlated to cellular behaviors controlled by cell-biomaterial interactions. Self-assembled monolayers (SAMs) of alkanethiols on gold were used as model biomaterials to investigate the effect of surface properties on nonviral gene transfer to cells adhered to these surfaces. SAMs presenting terminal CH₃, OH, COO^{- …}

St Monitoring On The Programmer For Implantable Cardioverter Devices, Sarina Satya

Master's Theses

Cardiovascular disease is one of the most prevalent causes of death which has a high mortality rate. If identified early and treated appropriately, the mortality in patients with cardiovascular disease can be hugely reduced. For several decades, 12-Lead ECG has been the standard technique used to identify ischemia, and recent studies have shown that intracardiac electrogram has many benefits over external monitoring such as holter. ST Monitoring feature has been added to St. Jude Medical intracardiac cardioverter defibrillators (ICD) to leverage the ECG technology for identifying cardiovascular disease. This algorithm monitors the intracardiac electrogram to detect and report patterns which …

Links With Canada Benefit Dit Prosthesis Research, Colm O'Kane

Articles

Colm O’Kane is a lecturer in the School of Manufacturing and Design Engineering and a member of the DIT Biomedical Device and Assistive Technology Research Group. He is currently engaged in PhD research in the field of knee prosthesis development, focused on developing optimised strategies for partial and total joint replacements used in treatment of osteoarthritis of the knee joint. This article is an account of a research scholarship sponsored by the CHC Helicopter Corporation and awarded by the Ireland Canada University Foundation (ICUF). This foundation awards annual scholarships for research visits between Ireland and Canada with the aspiration of …

The Effect Of Ace Inhibition On The Pulmonary Vasculature In Combined Models Of Chronic Hypoxia And Pulmonary Arterial Banding In Sprague Dawley Rats, Shanelle Clarke, Shelley Baumgardt, Robert C. Molthen

Biomedical Engineering Faculty Research and Publications

Microfocal CT was used to image the pulmonary arterial (PA) tree in rodent models of pulmonary hypertension (PH). CT images were used to measure the arterial tree diameter along the main arterial trunk at several hydrostatic intravascular pressures and calculate distensibility. High-resolution planar angiographic imaging was also used to examine distal PA microstructure. Data on pulmonary artery tree morphology improves our understanding of vascular remodeling and response to treatments. Angiotensin II (ATII) has been identified as a mediator of vasoconstriction and proliferative mitotic function. ATII has been shown to promote vascular smooth muscle cell hypertrophy and hyperplasia as well as …

Predicting Neointimal Hyperplasia In Stented Arteries Using Time-Dependant Computational Fluid Dynamics: A Review, Jonathan Murphy, Fergal Boyle

Articles

This paper reviews the recent literature regarding the time-dependant computational fluid dynamics (CFD) analyses of blood flow through implanted coronary stents. The in vivo processes which result in arterial restenosis are identified. The definition and range of the computationally predicted variables which are believed to stimulate the restenosis processes are evaluated. The reviewed literature is subdivided into effect-based in which the effects of altering the flow model are investigated and design-based in which different geometric stent configurations are compared. Finally, conclusions are made regarding the body of work reviewed and recommendations are provided for future work in this field.

An Investigation Of Humeral Stress Fractures In Racing Thoroughbreds Using A 3d Finite Element Model In Conjunction With A Bone Remodeling Algorithm, Ryan James Moore

Master's Theses

The humerus of a racing horse Thoroughbred is highly susceptible to stress fractures at a characteristic location as a result of cyclic loading. The propensity of a Thoroughbred to exhibit humeral fracture has made equines useful models in the epidemiology of stress fractures. In this study, a racing Thoroughbred humerus was simulated during training using a 3D finite element model in conjunction with a bone remodeling algorithm. Nine muscle forces and two contact forces were applied to the 3-dimensional finite element model, which contains four separate load cases representing fore-stance, mid-stance, aft-stance, and standing. Four different training programs were incorporated …

Surface Engineering Of Macrophages With Nanoparticles To Generate A Cell-Nanoparticle Hybrid Vehicle For Hypoxia-Targeted Drug Delivery, Christopher A. Holden, Quan Yuan, W. Andrew Yeudall, Deborah A. Lebman, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Tumors frequently contain hypoxic regions that result from a shortage of oxygen due to poorly organized tumor vasculature. Cancer cells in these areas are resistant to radiation- and chemotherapy, limiting the treatment efficacy. Macrophages have inherent hypoxia-targeting ability and hold great advantages for targeted delivery of anticancer therapeutics to cancer cells in hypoxic areas. However, most anticancer drugs cannot be directly loaded into macrophages because of their toxicity. In this work, we designed a novel drug delivery vehicle by hybridizing macrophages with nanoparticles through cell surface modification. Nanoparticles immobilized on the cell surface provide numerous new sites for anticancer drug …

Time-Efficient Patient-Specific Quantification Of Regional Carotid Artery Fluid Dynamics And Spatial Correlation With Plaque Burden, John F. Ladisa, Mark Bowers, Leanne Harmann, Robert W. Prost, Anil Vamsi Doppalapudi, Tayyab Mohyuddin, Osama Zaidat, Raymond Q. Migrino

Biomedical Engineering Faculty Research and Publications

Purpose:

Low wall shear stress (WSS) and high oscillatory shear index (OSI) influence plaque formation, yet little is known about their role in progression/regression of established plaques because of lack of practical means to calculate them in individual patients. Our aim was to use computational fluid dynamics(CFD) models of patients with carotid plaque undergoing statin treatment to calculate WSS and OSI in a time-efficient manner, and determine their relationship to plaque thickness (PT), plaque composition (PC), and regression.

Methods:

Eight patients (68±9 yr, one female) underwent multicontrast 3 T MRI at baseline and six-month post statin treatment. PT and PC …

Stiffness Of Vascular Smooth Muscle Cells From Aged Primates Measured Using Reconstituted Tissue Model, Shilpa Nagendra

Theses

Increased stiffness of the aorta is an important detrimental change that occurs with aging. Most previous research has implicated stiffening of the extracellular collagen matrix with age. The study reported in this thesis focused instead on the potential contribution from stiffening of the vascular smooth muscle cells (VSMCs) with age.

VSMCs previously obtained from young and old monkeys (macaca fascicularis) were seeded into a collagen gel to form a reconstituted tissue. The aim of this study was to quantitatively characterize the mechanical properties of this reconstituted tissue model via uniaxially stretching each ring to defined levels of strain. The total …

A Comparative Analysis Of Haptic And Eeg Devices For Evaluation And Training Of Post-Stroke Patients Within A Virtual Environment, Gregory Nicholas Ranky

Theses

Virtual Rehabilitation benefits from the usage of interfaces other than the mouse and keyboard, but also possess disadvantages: haptic peripherals can utilize the subject's hand to provide position information or joint angles, and allow direct training for specific movements; but can also place unneeded strain on the limbs; brain-machine interfaces (BMI) can provide direct connections from the user to external hardware or software, but are currently inaccurate for the full diversity of user movements in daily life and require invasive surgery to implement. A compromise between these two extremes is a BMI that can be adapted to specific users, can …

Development Of A Device For Whole Body Stimulation Of The Otoliths, Jon Edward Weimer

Theses

Over the past few decades, research has been conducted to explore the effects of microgravity on human musculature, As seen in astronauts upon their return to Earth after prolonged spaceflight, extensive muscle atrophy due to adaptation to conditions of microgravity many times decreases a person's ability to walk or even stand, With an understanding of the anatomical mechanisms that provide postural control, the proper stimulation, resulting in a reduction in spasticity, could be provided by simulating these conditions of microgravity.

In order to simulate microgravity, a device has been developed that is capable of providing whole body stimulation of the …

Life Cycle Greenhouse Gas Emissions From Biofuels: Variability, Uncertainty, And Steps Toward Accurate Regulation, Adam J. Liska, Bruce E. Dale

Adam Liska Papers

a)Variability in life cycle greenhouse gas (GHG) emissions from corn-ethanol:
biorefineries
cropping systems
co-product feeding to livestock

b) EPA regulation of life cycle GHG emissions from biofuels & use of life cycle analysis (LCA):
uncertainties & inaccuracies
indirect effects

c) Building accurate knowledge infrastructure, theory, and research teams for accurate LCA methods for biofuels

A Multi-Variable Analysis Of Transient Near-Wall Haemodynamics In A Stented Coronary Artery, Jonathan Murphy, Fergal Boyle

Conference Papers

No abstract provided.

Merlin.Net Automation Of External Reports Verification Process, Gabriel John Wettlaufer

Master's Theses

Merlin.net Patient Care Network is a St. Jude Medical product that is used for remote patient management. The basic concept of Merlin.net is to allow the physician to view patient device follow-up information as well as general patient and device information on a web application. The Merlin.net system also interfaces with the patient and will send them notification if they miss a follow-up. All device information will be collected automatically while the patient is sleeping. This information is sent through a telephone line to a Merlin.net server to process a report package and display the collected information on the Merlin.net …

Finite Element Modeling Of Stress Urinary Incontinence Mechanics, Thomas A. Spirka

ETD Archive

Stress urinary incontinence is characterized by the involuntary transurethral loss of urine caused by an increase in abdominal pressure in the absence of a bladder contraction that raises the vesical pressure to a level that exceeds urethral pressure. Adult women are most commonly affected by SUI which is believed to be caused in part by injuries to the pelvic floor sustained during childbirth. In spite of the large number of women affected by SUI, little is known about the mechanics associated with the maintenance of continence in women. In theory the mechanics underlying the mechanics of female continence can be …

Reflections Of College Students Promoting Engineering Through Biomechanical Outreach Activities Indicate Dual Benefits, Kimberly Edginton Bigelow

Mechanical and Aerospace Engineering Faculty Publications

Recent work by the National Academy of Engineering revealed that the public has a poor understanding of what engineers actually do on a day-to-day basis. This issue is compounded for non-traditional fields in engineering, such as biomechanical engineering. This is particularly problematic as such fields could draw interest from students not interested in traditional engineering careers, resulting in increased diversity.

To address this, mechanical engineering students taking an elective course, Biomechanical Engineering, were given an outreach assignment to teach at least one individual under the age of 18 about the field of biomechanical engineering through a hands-on activity. Students worked …

Department Of Biological Systems Engineering Newsletter, Volume 6, Number 1, January 2010

BSE Department Magazine

No abstract provided.

Electrohydrodynamic Atomization For Improved Macromolecular Drug Delivery, Michelle Zeles-Hahn

Electronic Theses and Dissertations

With advances in drug research, the use of biological therapeutics is becoming a reality. Unfortunately, methods for processing and delivering these fragile macromolecules often limit their therapeutic potential. For this dissertation, we explore the aerosolization of macromolecules by way of electrohydrodynamic atomization (EHDA) and how this method can be used to process and deliver therapeutics. EHDA employs a high voltage to break a column of liquid into drops. It was unknown if or how the residual charge left of the resulting droplets would affect lung cells. An in vitro experiment was conducted to spray aerosolized DNA, by way of EHDA, …

In-Vivo Testing Of Vertically Aligned Nanowire Implantable Titanium Electrodes In The Rattus Norvegicus Hippocampus, Lauren Kegley

Inquiry: The University of Arkansas Undergraduate Research Journal

Miniaturized multielectrode arrays are MEMS devices that have found use as neural prosthetics (Neuro-MEMS). As implants, they can interface with neurons as sensors or actuators and help compensate for loss of sensory input, motor control, or cognitive functions. The microelectrodes studied here were developed in-house. They have a vertically aligned gold nanowire array and are mounted on a sturdy titanium needle with a fine gauge. Hence, the bill of materials and design characteristics encourage their use as a neural probe. For this study, a probe was tested in vivo for signal acquisition in the hippocampus of a Rattus Norvegicus (Sprague …

Ablation Of Chronic Total Occlusions Using Kilohertz-Frequency Mechanical Vibrations In Minimally Invasive Angioplasty Procedures., Garrett Mcguinness, Mark Wylie, Graham Gavin

Articles

Certain minimally invasive cardiology procedures, such as balloon angioplasty and stent implantation, critically require that the site of an arterial blockage be crossed by an intraluminal guidewire. Plaques resulting in near or totally occluded arteries are known as chronic total occlusions (CTOs), and crossing them with conventional guidewires is a significant challenge. Among the most promising proposed solutions is the delivery of high power, low frequency ultrasonic vibrations to the occlusion site via an intraluminal wire waveguide. The vibrating distal-tip of the ultrasound wire waveguide is used to transmit energy to the surrounding plaques, tissues and fluids in order to …

Influence Of Compressible Aerogel Electrodes On The Properties Of An Electrochemical Cell, Chris Sponheimer

Electronic Theses and Dissertations

In the biomedical field the need for intra organ pressure measurement can only be facilitated by adapting existing pressure sensing technology to the specific tissues under test. The customization of these sensors has only driven up cost and the need to explore new technologies has become increasingly more important. For this dissertation, we explore the use of a new technology, particularly electrochemical pressure sensing to provide a low-cost pressure sensor to fill this need. Preliminary testing showed that electrically conductive polymers exhibited a change in voltage when pressurized if bubbles were first electrolyzed in the gel creating an aerogel, and …

A Review Of Autoimmune Diseases Associated With Cancer, Patricia Tai, Edward Yu, Kurian Joseph, Thomas Miale

Oncology Publications

The focus of this review is on the relationships between autoimmune diseases and cancer from two closely related perspectives: 1.Those autoimmune diseases which are often associated with malignancies. 2.Those prevalent cancers which may increase the risks of developing autoimmune disorders. The review concludes with a brief discussion of some selected innovative approaches to cancer immunotherapy.

Applications Of Ultrafine Powder Coatings, A.S. Mohammad Sayem Mozumder

Digitized Theses

Powder coatings have emerged as an alternative to the conventional liquid coatings when environmental regulations become stricter every year. The advantage of powder coatings mainly renders to their solvent-free formulations, because solvent(s) used in liquid coatings are to be evaporated to environment contributing to the total volatile organic compounds (VOCs) emissions. Although advantageous, until recently, powder coating was not able to provide surface finishes comparable to the liquid coatings. However, when ultrafine powders (particularly, in the size range of 15-25 µm) becomes flowable with the aid of nano-additive(s), ultrafine powder coatings (UPCs) came into business with its thinner and smoother …

Design, Development And Biomechanical Analysis Of Scaffolds For Augmentation Of Rotator Cuff Repairs, Amit Aurora

ETD Archive

Rotator cuff tears are a source of debilitating pain that commonly affects more than 40 of our aging population. Despite advances in surgical treatment, the failure rate of rotator cuff repairs is as high as 20-90 . Extracellular matrix (ECM) derived scaffolds have recently been investigated as augmentation devices for rotator cuff repairs, but none has yet demonstrated both the appropriate biological and mechanical properties for mitigating re-tears and enhancing healing. This dissertation proposes to engineer the mechanical properties of allograft fascia lata in a manner that will allow its use as an augmentation device for rotator cuff repairs. This …

Surface Microtopography Modulation Of Biomaterials For Bone Tissue Engineering Applications, Eun Jung Kim

ETD Archive

The ultimate goal of this project is to develop a biodegradable and implantable scaffold with precise surface topographies that can provide osteoconductive stimuli to connective tissue progenitor cells (CTPs), and subsequently, enhance bone regeneration applications without the complications of autogenous cancellous bone grafts. This dissertation presents the modification of surface microtextures to provide osteoconductive stimuli to CTPs for bone regeneration applications. First, the effect of surface topography on cell proliferation and osteogenic differentiation was validated through experiments using surface post microtextures and CTPs. Post microtextures accelerated CTP growth behaviors compared to smooth polydimethylsiloxane (PDMS) and standard cell culture dishes. Second, …

Evaluation Of Upper Motor Neuron Pathology In Amyotrophic Lateral Sclerosis By Mri;Towards Identifying Noninvasive Biomarkers Of The Disease, Venkateswaran Rajagopalan

ETD Archive

Amyotrophic lateral sclerosis (ALS) is the commonest adult motor neuron disease (MND) which causes progressive muscle paralysis and death usually within 5 years of symptom onset. As a result, only ╠â30,000 individuals in the United States are afflicted at any one time even though 5,000 or more individuals are diagnosed yearly. The diagnosis of ALS requires evidence of degeneration in upper motor neurons (UMNs) in the brain and in lower motor neurons (LMNs) that exit the brainstem and spinal cord to innervate skeletal muscles. Diagnosis can be incorrect or delayed when disease is early or atypical because non-invasive objective tests …

Cell-Taught Gene Therapy For The Preservation And Regeneration Of Cardiac Tissue Following Chronic Heart Failure, Srividya Sundararaman

ETD Archive

Heart failure is the primary cause of mortality and morbidity in the Western world. Although cell therapy has demonstrated improvement in cardiac function, these benefits are being attributed to the activation of paracrine factors, rather than the differentiation and integration of the transplanted cells into the host tissue. Based on this knowledge the focus of this thesis work was to deliver paracrine factors, and evaluate its effect on cardiac function. Gene therapy has evolved as a promising option to deliver pro-angiogenic proteins to infarct zones, thus providing cardiac benefit. This study has identified a gene design without the use of …

The Thermodynamics Of Fluid-Phase Benzene Via Molecular Simulation, John L. Tatarko

ETD Archive

Accurate values for thermodynamic properties throughout the fluid phase are a requirement for the design of separation processes. To date, very few pure substances have been completely characterized because of time and monetary constraints. Low cost computing power now permits complete determination of the thermodynamic properties of pure substances via molecular simulation. Molecular simulation is computational statistical mechanics. Benzene is an important industrial chemical and pharmaceutical precursor. It is the prototypical, symmetric, hexagonal molecule and is an ideal candidate for molecular simulation. The molecular models of three researchers in the field are submitted for Monte Carlo simulation in the virtual …