Biomedical Engineering and Bioengineering Commons^™

Diffusion Tensor Imaging And Tractography In Brown-Sequard Syndrome, A. Vendatam, Michael B. Jirjis, Brian D. Schmit, M. D. Budde, J. L. Ulmer, Mei Wang, S. N. Kurpad

Biomedical Engineering Faculty Research and Publications

This report illustrates the utility of DTI and DTT in delineating regions of cord injury in two patients with traumatic Brown-Sequard syndrome. Our results indicate that DTI provides clinically relevant information that supplements conventional MR imaging for patients with acute SCI.

Differential Lung Uptake Of 99mtc-Hexamethylpropyleneamine Oxime And 99mtc-Duramycin In The Chronic Hyperoxia Rat Model, Anne V. Clough, Said H. Audi, Steven Thomas Haworth, David L. Roerig

Biomedical Engineering Faculty Research and Publications

Noninvasive radionuclide imaging has the potential to identify and assess mechanisms involved in particular stages of lung injury that occur with acute respiratory distress syndrome, for example. Lung uptake of ^99mTc-hexamethylpropyleneamine oxime (HMPAO) is reported to be partially dependent on the redox status of the lung tissue whereas ^99mTc-duramycin, a new marker of cell injury, senses cell death via apoptosis or necrosis. Thus, we investigated changes in lung uptake of these agents in rats exposed to hyperoxia for prolonged periods, a common model of acute lung injury. Methods: Male Sprague–Dawley rats were preexposed to either normoxia (21% O …

Altered Hemodynamics, Endothelial Function, And Protein Expression Occur With Aortic Coarctation And Persist After Repair, Arjun Menon, Thomas J. Eddinger, Hongfeng Wang, David C. Wendell, Jeffrey M. Toth, John F. Ladisa

Biomedical Engineering Faculty Research and Publications

Coarctation of the aorta (CoA) is associated with substantial morbidity despite treatment. Mechanically induced structural and functional vascular changes are implicated; however, their relationship with smooth muscle (SM) phenotypic expression is not fully understood. Using a clinically representative rabbit model of CoA and correction, we quantified mechanical alterations from a 20-mmHg blood pressure (BP) gradient in the thoracic aorta and related the expression of key SM contractile and focal adhesion proteins with remodeling, relaxation, and stiffness. Systolic and mean BP were elevated for CoA rabbits compared with controls leading to remodeling, stiffening, an altered force response, and endothelial dysfunction both …

Functional Classification Of Skeletal Muscle Networks. I. Normal Physiology, Yu Wang, John Winters, Shankar Subramaniam

Biomedical Engineering Faculty Research and Publications

Extensive measurements of the parts list of human skeletal muscle through transcriptomics and other phenotypic assays offer the opportunity to reconstruct detailed functional models. Through integration of vast amounts of data present in databases and extant knowledge of muscle function combined with robust analyses that include a clustering approach, we present both a protein parts list and network models for skeletal muscle function. The model comprises the four key functional family networks that coexist within a functional space; namely, excitation-activation family (forward pathways that transmit a motoneuronal command signal into the spatial volume of the cell and then use Ca …

The Effect Of Cone Opsin Mutations On Retinal Structure And The Integrity Of The Photoreceptor Mosaic, Joseph Carroll, Alfredo Dubra, Jessica C. Gardner, Liliana Mizrahi-Meissonnier, Robert F. Cooper, Adam M. Dubis, Rick Nordgren, Mohamed Genead, Thomas B. Connor Jr., Kimberly E. Stepien, Dror Sharon, David M. Hunt, Eyal Banin, Alison J. Hardcastle, Anthony T. Moore, David R. Williams, Gerald Fishman, Jay Neitz, Maureen Neitz, Michel Michaelides

Biomedical Engineering Faculty Research and Publications

Purpose.

To evaluate retinal structure and photoreceptor mosaic integrity in subjects with OPN1LW and OPN1MW mutations.

Methods.

Eleven subjects were recruited, eight of whom have been previously described. Cone and rod density was measured using images of the photoreceptor mosaic obtained from an adaptive optics scanning light ophthalmoscope (AOSLO). Total retinal thickness, inner retinal thickness, and outer nuclear layer plus Henle fiber layer (ONL+HFL) thickness were measured using cross-sectional spectral-domain optical coherence tomography (SD-OCT) images. Molecular genetic analyses were performed to characterize the OPN1LW/OPN1MW gene array.

Results.

While disruptions in retinal lamination and cone mosaic structure were observed …

Biodiesel Production From Mixed Culture Algae Via A Wet Lipid Extraction Procedure, Ashik Sathish

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Development of renewable sources of energy has received significant interest due to the rising costs of energy and the environmental impact of using fossil fuels. Biodiesel production from renewable sources of oil has shown promise of helping to replace or reduce dependence on petroleum based diesel thereby reducing demand for crude oil. Microalgae have been considered as a strong candidate for the production of large quantities of renewable oil for biodiesel production.

Microalgae are single cell photosynthetic organisms that posses the capability to produce renewable oil at rates much faster than land based plants and crops. In addition, microalgae can …

Development Of A Closed-Loop Force Reduction Mechanism In A Gait Rehabilitation Device, Jeffrey Frankart

Theses and Dissertations

Elliptical trainers are prescribed in rehabilitative exercise but difficult to implement in populations with significant functional gait deficits. Typical elliptical machines do not mimic normal gait and therefore require modifications for clinical rehabilitation. This research builds on previous modifications of an elliptical trainer designed to simulate level-surface walking. This design differed from a commercial version. It included articulated footplates and an electromechanically-driven virtual-cam to control footplate position. Ankle dorsiflexion elicited lower-extremity muscle spasticity which produced an unwanted gait variant during stroke patient testing. Spasticity is a hyperexcitable stretch reflex causing inefficient gait. This project’s purpose was to develop an autonomous …

Compression Transmission Collar For Fastening, Patrick Atkinson

Mechanical Engineering Patents

A compression transmission collar apparatus (20) for implantation into a bone (22) with a hole (28) having a hole wall (32) comprising an intramedullary nail (34) defining a bore (40) and a threaded fastener (42) and a compression transmission collar (58) including an exterior face (64) and a top edge (60) and a bottom edge (62) and a first end (70) intersecting the top edge (60) at an acute angle (α₁) and …

Quantitative, Spectrally-Resolved Intraoperative Fluorescence Imaging, Pablo A. Valdés, Frederic Leblond, Valerie L. Jacobs, Brian C. Wilson, Keith D. Paulsen, David W. Roberts

Dartmouth Scholarship

Intraoperative visual fluorescence imaging (vFI) has emerged as a promising aid to surgical guidance, but does not fully exploit the potential of the fluorescent agents that are currently available. Here, we introduce a quantitative fluorescence imaging (qFI) approach that converts spectrally-resolved data into images of absolute fluorophore concentration pixel-by-pixel across the surgical field of view (FOV). The resulting estimates are linear, accurate, and precise relative to true values, and spectral decomposition of multiple fluorophores is also achieved. Experiments with protoporphyrin IX in a glioma rodent model demonstrate in vivo quantitative and spectrally-resolved fluorescence imaging of infiltrating tumor margins for the …

Reviewing The American University Law Review On Extraterritoriality: A Critical Response To Viki Economides, Note, Tianrui Group Co. V. Itc: The Dubious Status Of Extraterritoriality And The Domestic Industry Requirement Requirement Of Section 337(Link), Jonathan Stroud

Scholarly Articles in Law Reviews & Journals

Recently, the Federal Circuit upheld the Commission’s decision to exclude goods based on a trade secret violation that largely happened abroad. The American University Law Review critiqued that decision on two grounds: First, that a presumption against extraterritorial application of U.S. law applied; and second, that licensing alone could not establish a domestic industry. The American University Law Review's critique remains incomplete, however, as the Federal Circuit correctly decided the case for at least two reasons. first, the Federal Circuit correctly applied the “extraterritorial presumption” canon of construction; and second, the recent Federal Circuit decision in InterDigital Communications LLC v. …

Load-Relaxation Properties Of The Human Trunk In Response To Prolonged Flexion: Measuring And Modeling The Effect Of Flexion Angle, Nima Toosizadeh, Maury A. Nussbaum, Babak Bazrgari, Michael L. Madigan

Biomedical Engineering Faculty Publications

Experimental studies suggest that prolonged trunk flexion reduces passive support of the spine. To understand alterations of the synergy between active and passive tissues following such loadings, several studies have assessed the time-dependent behavior of passive tissues including those within spinal motion segments and muscles. Yet, there remain limitations regarding load-relaxation of the lumbar spine in response to flexion exposures and the influence of different flexion angles. Ten healthy participants were exposed for 16 min to each of five magnitudes of lumbar flexion specified relative to individual flexion-relaxation angles (i.e., 30, 40, 60, 80, and 100%), during which lumbar flexion …

Implementation Of Novel Group Delay Decomposition Method And Surgical Protocol For Assessing Peripheral Neuropathy, Sammy Paul Nicolas

Master's Theses

This paper outlines a surgical procedure for exposing and stimulating the sciatic nerve of an anesthetized rodent for purposes of obtaining conduction velocity readings. The ability to accurately quantify nerve conduction velocity has potential for use in the field of diagnostic medicine and disease characterization. An accurate reading depends on both the surgical method used to expose the desired nerve without imposing onto it any physical trauma as well as the stimulation protocol used to initiate action potentials. This paper contains the specific steps required to set up the necessary hardware and software for electrical stimulation as well as a …

The Design And Testing Of A Solar Autoclave With Broad Spectrum Sterilization Capabilities, Sarah S. Trabia

Honors College Theses

Energy is difficult to come by in developing countries and this interferes with the ability of doctors to provide good healthcare to their patients. Without decent sterilization, patients can become infected and diseases can spread throughout hospitals. This study involves designing a solar autoclave for developing countries that is as efficient as electrical autoclaves. The design is intended to not require any electrical input and to be affordable to those who cannot afford advanced medical equipment. Once the solar autoclave is designed, it will be tested to determine if it can sterilize equipment against a variety of different bacteria, including …

Mitigation Of Radiation Induced Pulmonary Vascular Injury By Delayed Treatment With Captopril, Robert C. Molthen, Qingping Wu, Brian L. Fish, John E. Moulder, Elizabeth R. Jacobs, Meetha M. Medhora

Biomedical Engineering Faculty Research and Publications

Background and Objective: A single dose of 10 Gy radiation to the thorax of rats results in decreased total lung angiotensin-converting enzyme (ACE) activity, pulmonary artery distensibility and distal vascular density while increasing pulmonary vascular resistance (PVR) at 2 months post-exposure. In this study, we evaluate the potential of a renin-angiotensin system (RAS) modulator, the ACE inhibitor captopril, to mitigate this pulmonary vascular damage.

Methods: Rats exposed to 10 Gy thorax only irradiation and age-matched controls were studied 2 months after exposure, during the development of radiation pneumonitis. Rats were treated, either immediately or 2 weeks after radiation exposure, with …

Noninvasive Optical Characterization Of Muscle Blood Flow, Oxygenation, And Metabolism In Women With Fibromyalgia, Yu Shang, Katelyn Gurley, Brock Symons, Douglas Long, Ratchakrit Srikuea, Leslie J. Crofford, Charlotte A. Peterson, Guoqiang Yu

Biomedical Engineering Faculty Publications

INTRODUCTION: Women with fibromyalgia (FM) have symptoms of increased muscular fatigue and reduced exercise tolerance, which may be associated with alterations in muscle microcirculation and oxygen metabolism. This study used near-infrared diffuse optical spectroscopies to noninvasively evaluate muscle blood flow, blood oxygenation and oxygen metabolism during leg fatiguing exercise and during arm arterial cuff occlusion in post-menopausal women with and without FM.

METHODS: Fourteen women with FM and twenty-three well-matched healthy controls participated in this study. For the fatiguing exercise protocol, the subject was instructed to perform 6 sets of 12 isometric contractions of knee extensor muscles with intensity steadily …

First-Order Design Of A Reflective Viewfinder For Adaptive Optics Ophthalmoscopy, Alfredo Dubra, Yusufu N. Sulai

Biomedical Engineering Faculty Research and Publications

Adaptive optics (AO) ophthalmoscopes with small fields of view have limited clinical utility. We propose to address this problem in reflective instruments by incorporating a viewfinder pupil relay designed by considering pupil and image centering and conjugation. Diverting light from an existing pupil optical relay to the viewfinder relay allows switching field of view size. Design methods that meet all four centering and conjugation conditions using either a single concave mirror or with two concave mirrors forming an off-axis afocal telescope are presented. Two different methods for calculating the focal length and orientation of the concave mirrors in the afocal …

Tyrosine Nitration Of Voltage-Dependent Anion Channels In Cardiac Ischemia-Reperfusion: Reduction By Peroxynitrite Scavenging, Meiying Yang, Amadou K.S. Camara, Bassam T. Wakim, Yifan Zhou, Ashish K. Gadicherla, Wai-Meng Kwok, David F. Stowe

Biomedical Engineering Faculty Research and Publications

Excess superoxide (O₂⁻) and nitric oxide (NO) forms peroxynitrite (ONOO⁻) during cardiac ischemia reperfusion (IR) injury, which in turn induces protein tyrosine nitration (tyr-N). Mitochondria are both a source of and target for ONOO⁻. Our aim was to identify specific mitochondrial proteins that display enhanced tyr-N after cardiac IR injury, and to explore whether inhibiting O₂⁻/ONOO⁻ during IR decreases mitochondrial protein tyr-N and consequently improves cardiac function. We show here that IR increased tyr-N of 35 and 15 kDa mitochondrial proteins using Western blot analysis with 3-nitrotyrosine antibody. Immunoprecipitation …

Functional Classification Of Skeletal Muscle Networks. Ii. Applications To Pathophysiology, Yu Wang, Jack Winters, Shankar Subramaniam

Biomedical Engineering Faculty Research and Publications

In our preceding companion paper (Wang Y, Winters J, Subramaniam S. J Appl Physiol. doi: 10.1152/japplphysiol.01514.2011), we used extensive expression profile data on normal human subjects, in combination with legacy knowledge to classify skeletal muscle function into four models, namely excitation-activation, mechanical, metabolic, and signaling-production model families. In this paper, we demonstrate how this classification can be applied to study two well-characterized myopathies: amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD). Using skeletal muscle profile data from ALS and DMD patients compared with that from normal subjects, normal young in the case of DMD, we delineate molecular mechanisms …

Easily Implantable And Stable Nail-Fastener For Skeletal Fixation And Method, Patrick Atkinson, David Lecronier

Mechanical Engineering Patents

An intramedullary nail (20) for insertion into the medullary canal (26) in a bone (24) surrounded by the cortex (28) and defines a bore (34) extending transverse to the intramedullary nail (20). A threaded fastener (22) extends along a fastener axis (A) and has a compression portion (48) having a compression portion diameter (DCP), and a threaded portion (50) having a threaded portion diameter (DTP) extending through a near cortex hole (40) and a far cortex hole (42), both holes (40, 42) radially overlapping the bore (34) and the threaded portion diameter (DTP) threadedly engaging the bore (34). A compression …

Impairments In Sensorimotor Control During Pursuit And Compensatory Tracking In Individuals With Multiple Sclerosis, Scott A. Beardsley, Heenan M., Robert A. Scheidt, D. Woo, J. Bobholz

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Differential Mitochondrial Toxicity Screening And Multi- Parametric Data Analysis, Maria V. Tsiper, Jennifer Sturgis, Larisa V. Avramova, Shilpa Parakh, Raymond Fatig, Ana Juan-García, Nianyu Li, Bartek Rajwa, Padma Narayanan, C. W. Wualls Jr., Joseph P. Robinson, Vincent J. Davisson

Weldon School of Biomedical Engineering Faculty Publications

Early evaluation of new drug entities for their potential to cause mitochondrial dysfunction is becoming an important task for drug development. Multi-parametric high-content screening (mp-HCS) of mitochondrial toxicity holds promise as a lead in-vitro strategy for drug testing and safety evaluations. In this study, we have developed a mp-HCS and multi-parametric data analysis scheme for assessing cell responses to induced mitochondrial perturbation. The mp-HCS measurements are shown to be robust enough to allow for quantitative comparison of biological systems with different metabolic pathways simulated by alteration of growth media. Substitution of medium glucose for galactose sensitized cells to drug action …

Monosynaptic Functional Connectivity In Cerebral Cortex During Wakefulness And Under Graded Levels Of Anesthesia, Jeannette A. Vizuete, Siveshigan Pillay, Kamran Diba, Kristina M. Ropella, Anthony G. Hudetz

Biomedical Engineering Faculty Research and Publications

The balance between excitation and inhibition is considered to be of significant importance for neural computation and cognitive function. Excitatory and inhibitory functional connectivity in intact cortical neuronal networks in wakefulness and graded levels of anesthesia has not been systematically investigated. We compared monosynaptic excitatory and inhibitory spike transmission probabilities using pairwise cross-correlogram (CCG) analysis. Spikes were measured at 64 sites in the visual cortex of rats with chronically implanted microelectrode arrays during wakefulness and three levels of anesthesia produced by desflurane. Anesthesia decreased the number of active units, the number of functional connections, and the strength of excitatory connections. …

Computational Model Of Neuron-Astrocyte Interputational Model Of Neuron-Astrocyte Interactions During Focal Seizure Generationactions During Focal Seizure Generation, Davide Reato, Mario Cammarota, Lucas C. Parra, Giorgio Carmignoto

Publications and Research

Empirical research in the last decade revealed that astrocytes can respond to neurotransmitters with Ca2+ elevations and generate feedback signals to neurons which modulate synaptic transmission and neuronal excitability. This discovery changed our basic understanding of brain function and provided new perspectives for how astrocytes can participate not only to information processing, but also to the genesis of brain disorders, such as epilepsy. Epilepsy is a neurological disorder characterized by recurrent seizures that can arise focally at restricted areas and propagate throughout the brain. Studies in brain slice models suggest that astrocytes contribute to epileptiform activity by increasing neuronal excitability …

An Indigoidine Biosynthetic Gene Cluster From Streptomyces Chromofuscus Atcc 49982 Contains An Unusual Indb Homologue, Dayu Yu, Fuchao Xu, Jonathan Valiente, Siyuan Wang, Jixun Zhan

Biological Engineering Faculty Publications

A putative indigoidine biosynthetic gene cluster was located in the genome of Streptomyces chromofuscus ATCC 49982. The silent 9.4-kb gene cluster consists of five open reading frames, named orf1, Sc-indC, Sc-indA, Sc-indB, and orf2, respectively. Sc-IndC was functionally characterized as an indigoidine synthase through heterologous expression of the enzyme in both Streptomyces coelicolor CH999 and Escherichia coli BAP1. The yield of indigoidine in E. coli BAP1 reached 2.78 g/l under the optimized conditions. The predicted protein product of Sc-indB is unusual and much larger than any other reported IndB-like protein. The N-terminal portion of this enzyme resembles IdgB and the …

Toe Brace Designs, Tarun Goswami, Allison L. Van Horn, Alexander O. Sheets

Biomedical, Industrial & Human Factors Engineering Faculty Publications

In various embodiments, provided are braces for use in supporting the metatarophalangeal joint, reducing or maintaining the intermetatarsal angle, enhancing or maintaining alignment of the hallux, or combinations thereof in a subject having hallux valgus.

An Information Architecture For Icme, William Marsden

Harnessing The Materials Genome: Accelerated Materials Development via Computational and Experimental Tools

No abstract provided.

Multiscale Modeling For Material Design Of Solid Oxide Fuel Cell Electrode, Y. Umeno, S. Hara, T. Tada, N. Shikazono

Harnessing The Materials Genome: Accelerated Materials Development via Computational and Experimental Tools

No abstract provided.

Some (Other) Uses Of Diffusion Couples In Metallurgy: Model Calibration And Mapping Transitions In Mechanisms, Christopher Hutchinson

Harnessing The Materials Genome: Accelerated Materials Development via Computational and Experimental Tools

No abstract provided.

From Genome To Flying Cyberalloys: The First Half Century, G. B. Olson

Harnessing The Materials Genome: Accelerated Materials Development via Computational and Experimental Tools

No abstract provided.

A Hybrid Computational-Experimental Approach For Automated Crystal Structure Solution, Bryce Meredig, Scott Kirklin, Chris Wolverton

Harnessing The Materials Genome: Accelerated Materials Development via Computational and Experimental Tools

No abstract provided.