Engineering Commons^™

Fabrication Of Aligned Nanofiber Yarns, Mats And Isolation Of Single Nanofiber In Electrospinning, Venkatesh T. Nathilvar

Theses

Electrospinning has been extensively used as an effective technique for the fabrication of submicron and nanometer scale polymeric fibers. In spite of technological advances in electrospinning, creating a highly aligned fiber structure is a tough target to be achieved because of the chaotic motion of the electrospinning jet. In this study, two different techniques have been adopted to form a highly aligned nanofibrous scaffolds. Using these methods highly aligned fiber yams and mats are produced from Cellulose Acetate (CA) in a mixed solvent of acetone and water. In both the techniques the nanofibers suspend over the gap in a highly …

Development Of A System To Measure Cardiac Function In The Drosophila Melanogaster Animal Model, Heather Anne Reinhardt

Theses

Previous studies have shown that several genes are evolutionarily conserved from lower organisms to man, where a number of genes have been directly linked to cardiac function and disease. The Drosophila melanogaster (Fruit Fly) has a genome similar to humans and therefore has proven to be an important animal model to study the role of genetics in cardiac function and disease development. Fruit flies are an important basic science model because of the ease with which genes can be manipulated and quickly expressed due to the short lifespan of the fly. Although standard techniques exist to affect the genome of …

Pda Based Ambulatory Pulse Oximeter, Arpita Shah

Theses

The main aim of the research was to develop an ambulatory pulse oximeter which can be used to monitor the SpO₂ heart rate (HR) and plethsymograph (PPG) waveform of a person. To achieve this, an algorithm was developed in LabVIEW 8.0 to extract the HR, SpO₂ and PPG data from a Nonin Xpod device, Nonin Medical, Inc. LabVIEW PDA software was developed to make it compatible with the PDA. LabVIEW software was also developed for sending the data to the PDA via Bluetooth Pulse Oximeter commercialized by Nonin Medical Company.

Using this algorithm, data was collected from three …

Preliminary Results For A Monocular Marker-Free Gait Measurement System, Jane Courtney, Annraoi Depaor

Articles

This paper presents results from a novel monocular marker-free gait measurement system. The system was designed for physical and occupational therapists to monitor the progress of patients through therapy. It is based on a novel human motion capture method derived from model-based tracking. Testing is performed on two monocular, sagittal-view, sample gait videos – one with both the environment and the subject’s appearance and movement restricted and one in a natural environment with unrestricted clothing and motion. Results of the modelling, tracking and analysis stages are presented along with standard gait graphs and parameters.

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

Mr Susceptibility Weighted Imaging And Its Clinical Applications, Nandita R. Shetty

Bioengineering Theses - Archive

Susceptibility Weighted Imaging (SWI) is a new T2* weighted Gradient Echo sequence that exploits the magnetic properties of tissues due to local inhomogeneities in the magnetic field. This technique was originally called 'High-Resolution Blood oxygen level dependent Venography' which, as the name suggests provides an increased visibility of the venous vasculature in the brain, including the minute vessels not seen on conventional imaging techniques. Since its potential is not restricted to venography, it was renamed 'Susceptibility Weighted Imaging ' due to its contrast mechanism being the susceptibility differences between two tissues. The essential feature in this technique is to tap …

A Novel Approach In The Detection Of Obstructive Sleep Apnea From Electrocardiogram Signals Using Neural Network Classification Of Textural Features Extracted From Time-Frequency Plots, Mohammad Alabed

Bioengineering Theses - Archive

Sleep-Disordered Breathing (SDB) is estimated to have a prevalence of 5% in middle-aged population. The population is widely thought to be under diagnosed, since the present method to detect and diagnose SDB, Nocturnal Polysomnography (NPSG), is still expensive and not accessible by most. SDB has been shown to affect the productivity and degree of life of the patient, and to have a high correlation with obesity and cognitive heart failure (CHF). Cheap and accessible means to screen the population for SDB are greatly pursued. This work presents an automatic algorithm to detect obstructive sleep apnea (OSA) events in 15-minute clips. …

Influence Of Polymer Surface Chemistry On The Recruitment Of Stem Cells In Mice, Shwetha Kamath

Bioengineering Theses - Archive

The most troublesome biological response to the implantation of bloodcontacting biomaterials is inflammation, which thereby-sets in motion a cascade of adverse host responses. If devices for therapy and drug delivery could be developed that prevent such responses from occurring altogether, a new generation of "stealth" biomaterials would be born. Such was the motivation of this project, which sought to investigate using mouse subcutaneous implantation model, the implant mediated host tissue responses to surfaces differing in their functionalities. During the course of a previous study in our laboratory, we accidentally discovered the presence of stem cells and their accumulation at the …

Characterization Of A Noninvasive, In Vivo, Microscopic Hyperspectral Imaging System For Microvascular Visualization., Bhavesh Shah

Bioengineering Theses - Archive

Instrumentation with clinical implications for imaging the human oculus was developed, based upon the hyperspectral imaging modality. The novel, non invasive, microscopic multi-modal hyperspectral imaging system, which operates in the visible as well as near infrared region, is capable of generating images illustrating spatial distribution of oxyhemoglobin contributions. The device principally comprises of a liquid crystal tunable filter and a focal plane array detector that is integrated to the slit lamp microscope. A proof of principle clinical study involving ten healthy subjects was undertaken to image the microvascular structure within the dermal tissue within the near infrared region, however these …

Design And Construction Of A Fast Spectrometer For Fourier Domain Optical Coherence Tomography, Manish Kankaria

Bioengineering Theses - Archive

A fast spectrometer capable of operating at 27.8 KHz is designed and calibrated to work in the wavelength range of 700-900 nm, to perform Fourier Domain Optical Coherence Tomography (FD-OCT). The OCT system is based on fiber-based Michelson's interferometer set up utilizing the spectrometer at the detector end. In FD-OCT system no reference scanning is necessary and hence images can be acquired at a much faster rate without any penalty to signal-to-noise ratio (SNR). A broadband Ti- sapphire source is used as input to this interferometer. Data at the rate of 60 MHz is acquired from the spectrometer using a …

An Investigation Into The Structure And Reactivity Of Calcium-Zinc-Silicate Ionomer Glasses Using Mas-Nmr Spectroscopy, D. Boyd, Mark R. Towler, R. V. Law, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Polyalkenoate Cements (GPCs) for orthopaedic applications is retarded by the presence in the glass phase of aluminum, a neurotoxin. Unfortunately, the aluminum ion plays an integral role in the setting process of GPCs and its absence is likely to hinder cement formation. However, the authors have previously shown that aluminum-free GPCs may be formulated based on calcium zinc silicate glasses and these novel materials exhibit significant potential as hard tissue biomaterials. However, there is no data available on the structure of these glasses. 29Si MAS-NMR, differential thermal analysis (DTA), X-ray diffraction (XRD), and network crosslink density …

Possibilities Of Glutamate-Mediated Synaptic Like Activity In Somatosensory Mechanoreceptors Such As Pacinian Corpuscles?, Kevin Kopko

Renée Crown University Honors Thesis Projects - All

Pacinian Corpuscles (PCs) are somatosensory mechanoreceptors, composed of a central neurite, surrounded by layers of lamellae that make up the inner core, which are specialized glial cells, and fibroblast derived outer-core lamellae of the surrounding capsule. Several components specific to a chemical synapse (Vglut1, Vamp1, SNAP-23) were localized to both the neurite and the inner-core cells in feline mesenteric PCs using immunocytochemistry. However, it has long been postulated that the first synapse of the PC occurs at the dorsal column nuclei, or spinal cord, and that no classical synapse is present in the distal ending of the capsulated receptor. While …

Predictive Measures Of Tooth/Tooth Contact In Mastication, Elizabeth Klodd

Renée Crown University Honors Thesis Projects - All

Understanding the process of mastication, or chewing, is very important in humans. Understanding the way people chew can help craniofacial repair to victims of accidents or other conditions. Stages of chewing and swallowing have been categorized; however, it is currently unknown when exactly the teeth meet during mastication. Vertical motion data were obtained from seven subjects while chewing food of different consistencies. A videofluorograph collected the data and they were manipulated in Excel to be plotted as time vs. vertical displacement for the upper incisor tooth. The first and second derivatives of these motion-time charts were taken in order to …

Registration Of Beta-Cit Dopamine Transporter Spect Images, Abhinay Dilip Joshi

Bioengineering Theses - Archive

This work outlines a method for quantification of nigrostriatal dopaminergic neurons by means of SPECT using the cocaine derivative [123I] β-CIT (123I-labelled 2β-carbomethoxy-3β-(4-iodophenyl) tropane (β-CIT))as a radiotracer which binds with high affinity to the dopamine receptors. It has been validated (1) that the calculation of a simple ratio of specific/non-specific displaceable binding during a period of binding-equilibrium in the striatum about 20 hrs after the administration of a bolus injection of the tracer gives a strong and reliable index of the binding potential of dopamine uptake sites. Previous studies [2] have shown that the dopaminergic deficit in patients with Parkinson's …

Phenotypic Differences In The Behavior Of Immortalized Human Bronchial Epithelial Cells In Three Dimensional Culture Systems, Anusha Sridharan

Bioengineering Theses - Archive

Human Bronchial Epithelial Cells (HBECS) immortalized with viral oncoproteins E6/E7, are potentially malignant due to numerous chromosomal aberrations. Recently a model system was established in which HBECS were immortalized with Cyclin-dependent-kinase-4 (Cdk4) and human Telomerase Reverse Transcriptase (hTERT). These cells were shown to have intact p53 checkpoints and had well expressed differentiation markers. HBECS are non-tumorigenic as they do not form tumors in nude mice or colonies in soft agar. The purpose of this research was to establish the differences in phenotypic behavior between HBECS immortalized with E6/E7 viral oncoproteins and HBECS immortalized with Cdk4/hTERT. A three dimensional culture model …

Development Of A Multi-Channel Handheld Probe Designed For Near Infrared Spectroscopy And An Exploration Into Its Clinical Applications, Pradheep Raman

Bioengineering Theses - Archive

Near Infrared (NIR) spectroscopy and imaging has become popular in research fields for the past 2 decades. My research focuses on the development of a handheld, multi-channel, multi-separation probe for the low-cost, compact, NIR spectroscopy (LCC-NIRS) system and also on the exploration into its possible clinical applications. The work is divided into three parts. The first part deals with the development of the multi-separation probe with source-detector separation of 3.8 cm, 3.3 cm, 3.0 cm, and 2.3 cm. The probe is designed to work as a tri-wavelength system for the LCC-NIRS, which was developed earlier, consisting of one light emitting …

High Precision Spatial And Temporal Control Of Neural Circuitry Using Semi-Automated, Multiwavelength Nanopatterning System, Nagasandhya Mitnala

Bioengineering Theses - Archive

The ideal way to manipulate neurons would be to reversibly activate and inactivate neuronal firing and thus enable a bi-directional control. Many attempts have been made in the past to have such a tool. The traditional approach for controlling neural circuits is to generate a local electric field which has been shown to be highly effective at triggering action potentials in neurons [53]. Although the timing of the electrode stimulation is very precise, its specificity and spatial control are poor. Also, silencing neuronal activity is as important as stimulating it. Ed Boyden described a protein that switches off nerve firing …

Optimization Of Methods For In-Vitro Expansion And Cryopreservation Of Mammalian Stem Cells, Harikrishnan Balachandran

Bioengineering Theses - Archive

The recent advances in the field of Tissue Engineering have given rise to the need for a tremendous quantity of cells. The search for and use of an appropriate multipotent or pluripotent stem cells in tissue engineering is an emerging concept. Mesenchymal stem cells hold a very great deal of promise because of their capacity to self-renew and to differentiate into various lineages. These cells are very low in number in the body but their in vitro expansion capacity is very unique. Taking into consideration the lack of uniform approach for expansion of these MSCs and storing these cells for …

Transfected Cell Arrays For Assessment Of Estrogen Receptor Activation In Breast Cancer Cells, Angela K. Pannier, Zain Bengali, Eric A. Ariazi, V. Craig Jordan, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Transfected cell arrays represent a high-throughput approach to correlate gene expression with functional cell responses, based on gene delivery from a substrate that supports cell adhesion. These arrays provide the ability to express, in parallel, thousands of exogenous genes in live cells, giving real-time information on cellular physiology and gene function. While there have been advances in transfected cell arrays, improvements are needed to this technology, including increasing the cells types that can be efficiently transfected and developing better quantification and normalization methods. We have created an array using soft lithography techniques to pattern DNA-lipid complex deposition. Specifically, a mold …

Vascular Tortuosity Is Culprit To Abnormal Perfusion In 9l Gliosarcoma Tumor, M. M. Darpolar, Robert C. Molthen, F. C. Wu, Kathleen M. Schmainda

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Development Of Self-Assembled Monolayer-Based Cell Culture Platform Towards Fabrication Of A Three-Dimensional Bioreactor, Rajendra Kandoor Aithal

Doctoral Dissertations

The extracellular matrix (ECM) plays an important role in regulating a number of cellular properties and functions like cell differentiation, cell synthesis and degradation, cell viability and proliferation, cell function, and cell aging. Surface modification of planar substrates with self-assembled monolayers (SAMs) is a promising technique to achieve stable ECMs.

In this work, substrates such as silicon (Si), gallium arsenide (GaAs) and indium tin oxide (ITO) substrates were modified with SAMS containing amino (-NH2), methyl (-CH3), thiol (-SH) and carboxylic (-COOH) end groups and characterized using contact angle measurements, surface infrared (IR) spectroscopy and atomic force microscopy (AFM). Different cell …

Reliable In-Plane Velocity Measurements With Magnetic Resonance Velocity Imaging, Haosen Zhang, Sandra S. Halliburton, Andan K. Venkatachari, Randolph M. Setser, Richard D. White, George P. Chatzimavroudis

Chemical & Biomedical Engineering Faculty Publications

Magnetic resonance (MR) imaging is a well-known diagnostic imaging modality. In addition to its high-quality imaging capabilities, hydrogen-based MR can also provide non-invasively the velocity of water-based fluids in all three spatial directions (through-plane and in-plane) in an image. Many previous studies showed that MR velocity imaging can accurately measure the through-plane velocity. The aim of this study was to evaluate how reliable are the in-plane velocity measurements in an image. The axial velocity of water in horizontal tubes (inner diameter: 14.7–26.2 mm) was measured with segmented (fast) and non-segmented (slow) k-space MR velocity …

Ultrasonically Set Glass Polyalkenoate Cements For Orthodontic Applications, D. A. Tanner, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

There is an accepted clinical requirement for a luting cement that can be command set upon satisfactory placement of an orthodontic appliance onto dentition. This work evaluates the suitability of ultrasound, imparted from a dental scaler, as a potential mechanism for achieving this. The net setting times and subsequent compressive strengths of a range of commercial and experimental glass polyalkenoate cements (GPCs) were evaluated, using modified ISO 9917 methods, when set both chemically and by ultrasound. The ultrasound was applied to the GPC through an orthodontic brace. It was possible to command set GPCs by the application of five to …

Optimisation Of The Composition Of An Acrylic Bone Cement: Application To Relative Amounts Of The Initiator And The Activator/Co-Initiator In Surgical Simplex®P, S. Madigan, M. R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In cemented arthroplasties, the two-part self-curing acrylic bone cement is currently the only material used for anchoring the total joint replacement to the contiguous bone. In virtually all commercially available formulations of this cement, the agents used for the initiation and activation/co-initiation of the radical polymerisation reaction are benzoyl peroxide (BPO) and N, N dimethyl-paratoluidine (DMPT), respectively. There are no reports in the open literature on the rationale for the amounts of these and other constituents in the formulations of the cement. Given the concerns that have been raised in the literature regarding the effect of residual DMPT on the …

Effect Of Low Molecular Weight Heparin On Fracture Healing In A Stabilized Rat Femur Fracture Model, David J. Hak, Rena L. Stewart, Scott J. Hazelwood

Biomedical Engineering

The purpose of this studywas to evaluate the effect of low molecular weight heparin (LMWH) on fracture healing in a standard stabilized rat femur fracture model. A closed, mid-diaphyseal transverse fracture was created in the right femur of Long-Evans rats after insertion of a 0.8-mm K-wire into the medullarycanal. Animals were randomized to receive either LMWH (70 units/kg dalteparin) oraninjection of normal saline daily for 2 weeks. Animals were sacrificed at 2, 3, and 6 weeks. Fracture healing was assessedbyradiographs, histology, and mechanical testing. There were no significant differences between the control and LMWH groups in the percentage of animalswith …

Controlled Surface-Associated Delivery Of Genes And Oligonucleotides, Tatiana Segura, Lonnie D. Shea, Angela K. Pannier, Zain Bengali, Jae-Hyung Jang, Peter Chung, Brian C. Anderson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A system and methods for controlled gene delivery comprising condensed nucleic acids complexed with polylinkers, wherein the complexes are covalently and/or noncovalently bound to the surface of a substrate capable of supporting cell adhesion. The gene delivery system achieves temporal and spatial control of nucleic acid delivery to a target cell or cells through control of complex density on the surface of the support substrate, and reversibility of the attachment of the polylinker to the support substrate. The system and method of the invention can be used to create spatial patterns of gene expression, and in tissue engineering, high throughput …

Updated Asabe Standard Manure Excretion Standard, Richard K. Koelsch

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This newsletter introduces the new ASABE (American Society of Agricultural and Biological Engineers) Standard D384.2, Manure Production and Characteristics. This new standard provides an equation-based approach that integrates animal feeding program and performance into the final estimate of total solids, nitrogen, and phosphorus excretion for seven livestock and poultry species. This article reviews the opportunity this standard provides for improving accuracy of farm-specific nutrient management planning and introduces an educational opportunity for users to be introduced to new software for using the standard.

I propose to conduct one or more workshops on the standard and supporting software tool in June. …

Lung Circulation Modeling: Status And Prospect, Anne V. Clough, Said H. Audi, Robert C. Molthen, Gary S. Krenz

Biomedical Engineering Faculty Research and Publications

Mathematical modeling has been used to interpret anatomical and physiological data obtained from metabolic and hemodynamic studies aimed at investigating structure-function relationships in the vasculature of the lung, and how these relationships are affected by lung injury and disease. The indicator dilution method was used to study the activity of redox processes within the lung. A steady-state model of the data was constructed and used to show that pulmonary endothelial cells may play an important role in reducing redox active compounds and that those reduction rates can be altered with oxidative stress induced by exposure to high oxygen environments. In …

Quantitative Object Reconstruction Using Abel Transform Tomography And Mixed Variable Optimization, Kevin R. O'Reilly

Theses and Dissertations

Researchers at the Los Alamos National Laboratory (LANL) are interested in quantitatively reconstructing an object using Abel transform x-ray tomography. Specifically, they obtain a radiograph by x-raying an object and attempt to quantitatively determine the number and types of materials and the thicknesses of each material layer. Their current methodologies either fail to provide a quantitative description of the object or are generally too slow to be useful in practice. As an alternative, the problem is modeled here as a mixed variable programming (MVP) problem, in which some variables are nonnumeric and for which no derivative information is available. The …

Biological System Impedance Identification Using Stochastic Estimation And Control, Enrique Mendezaceves

Theses and Dissertations

In an effort to find a less invasive way of testing for different cell abnormalities and finding more practical tests for different cellular mutations, this project makes use of a well-known technique called cellular impedance spectroscopy coupled with stochastic estimation. Impedance spectroscopy, the measurement of the complex resistance of a biological body, is not a new technology; it has been around for many years and has been used to make electrical representations of different biological systems. The problem with this procedure is that models cannot be used for system identification. Stochastic estimation can complement a model produced by analyzing the …