Biomedical Engineering and Bioengineering Commons^™

Novel Auto-Calibrating Neural Motor Decoder For Robust Prosthetic Control, Andrew Earl Montgomery

Browse all Theses and Dissertations

The overarching goal of this project is to develop novel neural motor decoders for prosthetic control. EMG decoders measure the activity from an intact but non-target muscle. Neural motor decoders transform the signal measured from the severed motor axons of the target muscle. A multi-scale, highly-realistic computer model of a spinal motor pool was developed (Allen & Elbasiouny, 2018) to serve as a computational platform for decoder development and testing. A firing rate-based algorithm was developed to transform the aggregate discharge of the motor pool into a command signal to control the simulated prosthetic MuJoCo hand. This algorithm was informed …

Reversibly Switching Adhesion Of Smart Adhesives Inspired By Mussel Adhesive Chemistry, Ameya R. Narkar

Dissertations, Master's Theses and Master's Reports

Catecholic groups in mussel adhesive proteins transition from being strongly adhesive in a reduced state under acidic conditions to being weakly adhesive in an oxidized state under basic conditions. Here, we exploit this pH responsive behavior of catechol and demonstrate that its oxidation state can be manipulated by incorporation of boronic acid to facilitate reversible transitions between strong and weak adhesion. Our first approach involved the addition of 3- acrylamido phenylboronic acid (APBA) to dopamine methacrylamide (DMA) containing adhesives. The synthesized adhesives showed strong adhesion to quartz surface in an acidic medium (pH 3), while weak adhesion was observed on …

Development Of Novel Models To Study Deep Brain Effects Of Cortical Transcranial Magnetic Stimulation, Farheen Syeda

Theses and Dissertations

Neurological disorders require varying types and degrees of treatments depending on the symptoms and underlying causes of the disease. Patients suffering from medication-refractory symptoms often undergo further treatment in the form of brain stimulation, e.g. electroconvulsive therapy (ECT), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), or transcranial magnetic stimulation (TMS). These treatments are popular and have been shown to relieve various symptoms for patients with neurological conditions. However, the underlying effects of the stimulation, and subsequently the causes of symptom-relief, are not very well understood. In particular, TMS is a non-invasive brain stimulation therapy which uses time-varying magnetic …

Integration Of Biology, Ecology And Engineering For Sustainable Algal‑Based Biofuel And Bioproduct Biorefinery, James Allen, Serpil Unlu, Yaşar Demirel, Paul N. Black, Wayne R. Riekhof

Department of Chemical and Biomolecular Engineering: Faculty Publications

Despite years of concerted research efforts, an industrial-scale technology has yet to emerge for production and conversion of algal biomass into biofuels and bioproducts. The objective of this review is to explore the ways of possible integration of biology, ecology and engineering for sustainable large algal cultivation and biofuel production systems. Beside the costs of nutrients, such as nitrogen and phosphorous, and fresh water, upstream technologies which are not ready for commercialization both impede economic feasibility and conflict with the ecological benefits in the sector. Focusing mainly on the engineering side of chemical conversion of algae to biodiesel has also …

Multiple Factors Drive Variation Of Forest Root Biomass In Southwestern China, Hao Zhang, Kelin Wang, Zhaoxia Zeng, Zhigang Zou, Yanfang Xu, Fuping Zeng

Nebraska Center for Biotechnology: Faculty and Staff Publications

The roots linking the above-ground organs and soil are key components for estimating net primary productivity and carbon sequestration of forests. The patterns and drivers of root biomass in forest have not been examined well at the regional scale, especially for the widely distributed forest ecosystems in southwestern China. We attempted to determine the spatial patterns of root biomass (RB, Mg/ha), annual increment root biomass (AIRB, Mg/ha/year), ratio of root and above-ground (RRA), and the relative contributions of abiotic and biotic factors that drive the variation of root biomass. Forest biomass and multiple factors (climate, soil, forest types, and stand …

Diversity And Functional Evolution Of Terpene Synthases In Dictyostelid Social Amoebae, Xinlu Chen, Tobias G. Kollner, Gad Shaulsky, Qidong Jia, Jeroen S. Dickschat, Jonathan Gershenzon, Feng Chen

Nebraska Center for Biotechnology: Faculty and Staff Publications

Dictyostelids, or social amoebae, have a unique life style in forming multicellular fruiting bodies from unicellular amoeboids upon starvation. Recently, dictyostelids were found to contain terpene synthase (TPS) genes, a gene type of secondary metabolism previously known to occur only in plants, fungi and bacteria. Here we report an evolutionary functional study of dictyostelid TPS genes. The number of TPS genes in six species of dictyostelids examined ranges from 1 to 19; and the model species Dictyostelium purpureum contains 12 genes. Using in vitro enzyme assays, the 12 TPS genes from D. purpureum were shown to encode functional enzymes with …

Non-Targeted Colonization By The Endomycorrhizal Fungus, Serendipita Vermifera, In Three Weeds Typically Co-Occurring With Switchgrass, Prasun Ray, Yingqing Guo, Jaydeep Kolape

Nebraska Center for Biotechnology: Faculty and Staff Publications

Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830) is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted …

Predictive Modeling Of Hip Dislocation: Assessment Of Surgical And Patient Factors To Reduce The Occurrence Of Hip Instability And Adverse Clinical Outcomes, Daniel N. Huff

Electronic Theses and Dissertations

Instability and dislocation remain leading indications for revision of primary Total Hip Arthroplasty (THA). Many studies have addressed the links between implant design and propensity for dislocation, however a comprehensive review of the ability of modern THA constructs to protect against joint instability is needed.

Accordingly, the objective of this study is to provide objective data about THA risks to be considered in the treatment algorithm to protect against adverse joint loading conditions and joint instability. Adverse loading conditions were assessed in a population of activities of daily living using data from telemetric hip implant representation in an FE simulation …

Computational Modeling Of Transcatheter Aortic Valves, Mostafa Abbasi

Electronic Theses and Dissertations

Transcatheter aortic valve replacement (TAVR) is an established therapy alternative to surgical valve replacement in high-risk and intermediate-risk patients with severe aortic stenosis. Currently, although TAVR is an alternative and less-invasive treatment for high-risk and intermediate-risk patients, surgical aortic valves replacement (SAVR) was still considered as the gold standard for low-risk patients. TAVR could potentially be applied to lower-risk younger patients if the indications can be safely expanded to the patients and transcatheter aortic valve (TAV) long-term durability can match with that of surgical bioprostheses. In contrast to surgical aortic valves (SAVs), there have been limited clinical data on the …

Effects Of Protein-Coated Nanofibers On Conformation Of Gingival Fibroblast Spheroids: Potential Utility For Connective Tissue Regeneration, Gili Kaufman, Ryan A. Whitescarver, Laiz Nunes, Xavier-Lewis Palmer, Drago Skrtic, Wojtek Tutak

Engineering Technology Faculty Publications

Deep wounds in the gingiva caused bytrauma or surgery require a rapid and robust healing of connective tissues. Wepropose utilizing gas-brushed nanofibers coated with collagen and fibrin for that purpose. Our hypotheses are that protein-coated nanofibers will: (i) attract and mobilize cells in various spatial orientations, and (ii) regulate the expression levels ofspecific extracellular matrix (ECM)-associated proteins, determining the initial conformational nature ofdense and soft connective tissues. Gingival fibroblast monolayers and3D spheroids were cultured onECMsubstrate and covered with gas-blown poly-(DL-lactide-co-glycolide)(PLGA) nanofibers (uncoated/coated with collagen and fibrin). Cell attraction and rearrangement was followed byF-actin staining and confocal microscopy. Thicknesses ofthe cell …

Knockdown Of Heparan Sulfate Via Ndst1 Knockout Does Not Inhibit Mouse Aortic Endothelial Cell Alignment In-Vivo, John Diaz De Leon Iii

Dissertations and Theses

Atherosclerotic plaque localizes in predictable areas such as arches and bifurcations which are characterized by disturbed flow patterns and the resulting damage and dysfunction to the endothelium. Endothelial cells (ECs) under sustained laminar flow align in the direction of flow; however, under disturbed flow conditions, ECs sustain damage to their glycocalyx (GCX) which results in unaligned and rounder cells. An investigation into the role of NDST1 sulfation of heparan sulfate (HS), a key component of many proteoglycans which make up the GCX, was conducted. The descending aortas (DAs) of transgenic mice with conditional knockouts (KOs) of NDST1 in vascular ECs …

Developing A 3d In Vitro Model By Microfluidics, Hung-Ta Chien

Dissertations and Theses

In vitro tissue models play an important role in providing a platform that mimics the realistic tissue microenvironment for stimulating and characterizing the cellular behavior. In particular, the hydrogel-based 3D in vitro models allow the cells to grow and interact with their surroundings in all directions, thus better mimicking in vivo than their 2D counterparts. The objective of this thesis is to establish a 3D in vitro model that mimics the anatomical and functional complexity of the realistic cancer microenvironment for conveniently studying the transport coupling in porous tissue structures. We pack uniform-sized PEGDA-GelMA microgels in a microfluidic chip to …

Collective Chemotaxis Of Retinal Neural Cells From Drosophila Melanogaster In Controlled Microenvironments, Stephanie Zhang

Dissertations and Theses

More than 172 million people are influenced by a retinal disorder that stems from either age-related or developmental causes. Of those, 1.5 million people endure a developmental retinal disorder. In the developing retina, neural cells undergo a series of highly complicated differentiation and migration process. A main cause of these diseases is abnormal collective migration of neural progenitors hindering the retinogenesis process. However, our grasp of collective migration and signaling molecules, critical to the developing retina, is incompletely understood. Understanding the molecular mechanisms, such as the fibroblast growth factor pathway, that regulate glial and neuronal migration provides decisive insights in …

The Effects Of Emerging Technology On Healthcare And The Difficulties Of Integration, Skyler J. Pavlish-Carpenter

Honors Undergraduate Theses

Background: Disruptive technology describes technology that is significantly more advanced than previous iterations, such as: 3D printing, genetic manipulation, stem cell research, innovative surgical procedures, and computer-based charting software. These technologies often require extensive overhauls to implement into older systems and must overcome many difficult financial and societal complications before they can be widely used. In a field like healthcare that makes frequent advancements, these difficulties can mean that the technology will not be utilized to its full potential or implemented at all.

Objective: To determine the inhibiting factors that prevent disruptive technology from being implemented in conventional healthcare.

Methods: …

Biomedical Informatics Applications For Precision Management Of Neurodegenerative Diseases, Justin B. Miller, Guogen Shan, Joseph Lombardo, Gustavo Jimenez-Maggoria

School of Public Health Faculty Research

Modern medicine is in the midst of a revolution driven by “big data,” rapidly advancing computing power, and broader integration of technology into healthcare. Highly detailed and individualized profiles of both health and disease states are now possible, including biomarkers, genomic profiles, cognitive and behavioral phenotypes, high-frequency assessments, and medical imaging. Although these data are incredibly complex, they can potentially be used to understand multi-determinant causal relationships, elucidate modifiable factors, and ultimately customize treatments based on individual parameters. Especially for neurodegenerative diseases, where an effective therapeutic agent has yet to be discovered, there remains a critical need for an interdisciplinary …

Review Of Emerging Approaches In Non- Or Minimally Invasive Glucose Monitoring And Their Application To Physiological Human Body Fluids, Sunghoon Jang, Chen Xu

Publications and Research

The frequent blood glucose monitoring by the diabetics and physicians is a very essential step in the management of the diabetes because this devastating disease can lead the patients to blindness, kidney disease, nervous & circulatory system disease, limb amputations, stroke and cardiovascular disease (CVD). There have been numerous attempts to develop viable painless non- or minimally invasive blood glucose monitoring techniques over the last five decades in order to replace all existing methods of home blood glucose monitoring require drawing a blood sample by piercing the skin. This review describes the principles of two main emerging general technologies such …

Study On Electrolyte-Gated Graphene Nanoelectronic Biosensors For Biomarker Detection, Jianbo Sun

Graduate Theses, Dissertations, and Problem Reports (ETD)

Biosensors are called upon to provide valuable benefits for human society in vital fields such as disease diagnosis, food inspection, environment monitoring, etc. Among the various biosensor architectures, the field effect transistor (FET) biosensors are promising as the next generation nanoelectronic biosensors, particularly attractive for point-of-care biomedical applications. The FET biosensors typically operate by measuring the conductance change of the semiconducting channel induced by the adsorption of the target biomolecules on it. The superior properties of graphene, including the unique electronic characteristics, facile functionalization and good biocompatibility, etc., make it an ideal building block for the FET biosensors. In this …

The Pattern Of Sensory Axonal Endings Together With Synaptic Transmission Influence The Development Of Proprioceptive Circuits In The Spinal Cord, Yiyun Dai

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Proprioceptive circuits provide information regarding limb position and movement status, and are essential to producing correctly executed motor behaviors. Exploring the mechanisms underlying the formation of proprioceptive circuits is therefore critical for understanding neurological disorders with altered motor coordination and for restoring circuits damaged by injury. One important proprioceptive circuit, the stretch reflex circuit, is formed between proprioceptive sensory neurons (PSNs) and motor neurons (MNs) that innervate the same muscle. Progress has been made in understanding the spatial organization of MNs based on their muscle-specific subpopulation identities, which contributes to the specificity of stretch reflex circuit formation. However, whether PSNs …

Electroceutical Therapy In Amyotrophic Lateral Sclerosis: A Novel Preliminary Study, Morgan Michelle Highlander

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Amyotrophic Lateral Sclerosis (ALS) is a fatal, neurodegenerative disease that is characterized by the death of motoneurons. Life expectancy is only 3-5 years from diagnosis and current treatments only extend survival by 2-3 months. The mechanism of motoneuron death in ALS is still largely unknown, but abnormal motoneuron excitability has been extensively documented. Because the intrinsic excitability of a motoneuron is a defining measure of its normal function, characterizing and regulating motoneuron excitability has become one of the primary aims of ALS research. Although not previously explored in ALS, other clinical applications show the ability of certain electroceutical techniques to …

Regulation Of The Motor Output Of The Spinal Cord: Burst Firing Generation And Sensorimotor Integration, Amr A. Mahrous

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Spinal motoneurons are the final common path for motor signals. Thus, the firing activity recorded from spinal motoneurons or their axons in the ventral roots represents the motor output of the nervous system. This dissertation investigates two major phenomena that help generate and shape the neuronal motor output. Specialized groups of spinal neurons called central pattern generators (CPGs) are capable of orchestrating rhythmic bursting activity without involvement of the brain. This activity underlies stereotyped movements such as locomotion. If known, the ionic mechanisms responsible for generating this activity can offer new pharmacological interventions to restore walking in paralyzed patients with …