Biomedical Engineering and Bioengineering Commons^™

Calcium And Zinc Ion Release From Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Mark R. Towler, S. Kenny, D. Boyd, T. Pembroke, M. Buggy, A. Guida, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Calcium and zinc ion release from hydroxyapatite-zinc oxide-poly (acrylic acid) (HAZnO-PAA) composite cements into deionised water was investigated as a function of HA content, PAA concentration, PAA molecular weight and maturation time. At any given maturation time, zinc ion release was constant until the HA content was at the maximum loading (60 wt%) resulting in the cement matrix breaking up, allowing exacerbated ion release. The calcium ion release increased with increased HA content in the composite until the maximum loading where the release drops off. Up to this point, the release of both ionic species was proportional to square root …

Characterization Of Hypertension Through Multivariate Analysis Utilizing Linear And Nonlinear Methods, Diane L. Donnelly

Dissertations

Analysis of blood pressure by nonlinear methods is vastly underutilized in current research. As such, 24-hour ambulatory blood pressure data from a small cohort of borderline hypertensive and normotensive subjects were analyzed using linear and nonlinear methods. Data were collected and provided by researchers from Columbia University. The cohort size was twelve subjects, consisting of two groups of six each. Although disease state was known, group membership for individual subjects was not. Therefore, one aspect of this research was to separate the cohort, a-priori, into two distinct, evenly sized groups, based solely on analysis results. Separation was accomplished by the …

Individual Cell Pressure Control In An Air Mattress For The Prevention Of The Pressure Sores, Kapilchandra Anand

Theses

Many kinds of pressure-relieving mattresses have been developed to prevent pressure sores in patients with spinal cord injuries (SCIs) and obesity. Current technology uses alternating air pressure mattress, foam and low pressure mattress for reducing the incidence of pressure sores in SCI and obesity patients. These mattresses do not have control of pressure in individual air chambers. They are open loop system and they do not receive any feedback from the system. They have at the most control of two different pressures. The purpose of this study is to improve the current assistive technology in reducing pressure sores and to …

In-Vitro Characterization Of Boronized Titanium Alloy By Means Of Corrosion And Electrochemical Impedance Spectroscopy Methods In Simulated Body Fluids, David Anthony Panus

Theses

Titanium and titanium alloys are becoming the backbone of medical implants and prosthetics. Titanium alloys are used because of its high biocompatibility and similarity to bone. However, titanium and titanium alloys have a low wear resistance. Titanium and titanium alloys are susceptible to particle erosion, which can cause inflammation, infection, and even implant rejection. Boronizing titanium alloy improves titanium's wear resistance and also improves corrosion resistance.

The target of this research was to characterize the corrosion characteristics of both unboronized and boronized titanium using both electrochemical corrosion methods and Electrochemical Impedance Spectroscopy (ELS) in simulated body fluid. Using electrochemical methods …

Fabrication Of Hydroxyapatite-Biodegradable Polymer Scaffolds By Electrospinning For Potential Bone Tissue Application, Satomi Suzuki

Theses

The purpose of this study is to determine the potential of combining hydroxyapatite (HA) and polymers to form synthetic composite materials used for bone tissue engineering applications. In this study, ceramic-biodegradable polymer composites are fabricated by electrospinning method. The biodegradable polymers used are poly(L-lactic acid) (PLLA), and poly(lactide-co-glycolide) (PLGA). Two types of HA-polymer solutions are first prepared to achieve HA weight percentage of 0, 10, and 25%of the total combined weight of HA and PLLA, and HA and PLGA. The solutions are electrospun to form nanofibrous mats incorporated with HA powder. A biomimetic process was also conducted as a …

Closure Of Earthern Manure Structures (Including Basins, Holding Ponds And Lagoons), Don D. Jones, Richard K. Koelsch, Saqib Mukhtar, Ronald Sheffield, John W. Worley

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

This paper is a summary of what is known scientifically about the closure of earthen manure structures without artificial liners, including lagoons, storage basins, and runoff holding ponds, and what needs to be examined further to increase our understanding of the dynamics of closing them in an environmentally safe manner. This information should be useful as a guide for state regulatory agencies considering rules for closure and for academicians and consultants who work with livestock production facilities.

Pre- And Post-Alpha Motoneuronal Control Of The Soleus H-Reflex During Sinusoidal Hip Movements In Human Spinal Cord Injury, Maria Knikou, Debjani Chaudhuri, Elizabeth Kay, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

The aim of this study was to establish the contribution of hip-mediated sensory feedback to spinal interneuronal circuits during dynamic conditions in people with incomplete spinal cord injury (SCI). Specifically, we investigated the effects of synergistic and antagonistic group I afferents on the soleus H-reflex during imposed sinusoidal hip movements. The soleus H-reflex was conditioned by stimulating the common peroneal nerve (CPN) at short (2, 3, and 4 ms) and long (80, 100, and 120 ms) conditioning test (C-T) intervals to assess the reciprocal and pre-synaptic inhibition of the soleus H-reflex, respectively. The soleus H-reflex was also conditioned by medial …

Department Of Biological Systems Engineering Newsletter, Issue 1, August 2006

BSE Department Magazine

Contents:
Welcome Comments from Department Head
Student Poster Exhibition
Quarter-scale Tractor Team
Distinguished Fellowship Awards
Scoops and Scholars
Educational Objectives
ASABE Honors Department Faculty and Staff Members
Computer Tool Helps Crop Production under Limited Irrigation
Comings and Goings
Milestones
Faculty and Staff News
Alumni Update
Alumni Profile
Graduation
UCare Spring 2006 Undergraduate Research
MSYM Student on Winning Team
A Nebraskan Goes Way South
Visitors to BSE

Flow Rate Measurement Of In Situ Perfusion Through The Aqueous Humor Outflow Network, Noel Ortiz Lawrence

Bioengineering Theses - Archive

A system was developed to measure the instantaneous perfusate flow rate through the aqueous humor outflow network of a human eye, while under constant pressure. The system monitors real-time weight changes of a perfusate reservoir associated with perfusate flow through the aqueous humor outflow network. The recorded weight changes of the reservoir are used as an indicator of flow rates. Methods to determine time and flow rate resolution and to control for evaporation were also developed. The system is capable of measuring flow on a uL/min scale; determined by the following model, which also includes a range of uncertainty (implies …

Detection Of Sleep Disordered Breathing Using Electroencephalography, Priya Xavier

Bioengineering Theses - Archive

This study investigates the application of Electroencephalography (EEG) to detect Sleep disordered breathing (SDB) using power spectral analysis. A preliminary study was performed on 13 subjects (ages: 49.08 ± 8.82) previously diagnosed with OSA. Power spectral analysis was performed and centered on apnea/hypopnea event terminations. The normalized power changes between the frequency bands delta, theta, alpha and sigma were calculated using the Welch Averaging Periodogram method between 10 s of EEG data before the event termination and 10 s of EEG data after event termination. A significant decrease in normalized delta power and a significant increase in normalized theta, alpha …

Characterization And Feasibility Study Of A Near Infrared Ccd Imager For Monitoring Tumor Hemodynamics, Manan Goel

Bioengineering Theses - Archive

Prostate cancer is one of the most common types of cancers diagnosed among North American men. Chemotherapy is generally used to target advanced metastatic prostate cancer. Near infrared spectroscopy (NIRS) has been previously investigated to monitor the hemodynamic changes in rat prostate tumors; however, the previous study with NIRS is limited by its spatial resolution. The goal of this study is to characterize an NIR, CCD imager and to explore the feasibility of using the CCD imager to non-invasively monitor hemodynamic changes in rat prostate tumors during gas intervention. Firstly, studies were conducted to characterize the CCD imager and understand …

Novel Techniques Of Fabricating Porous, Biodegradable Polymer Scaffolds For Sustained Drug Release, Mayur B. Uttarwar

Bioengineering Theses - Archive

Two types of porous scaffolds were made from biodegradable polymers and their drug release trends and rates were studied. In first method, the emulsion of PLLA in chloroform solution and PVA and acetaminophen in de-ionized water solution was made. The emulsion was blended with PLLA solution. The resultant emulsion was freeze vacuum dried. The drug release study was conducted in-vitro. In the second method, scaffolds had three layers. The top and bottom layers were made by blending PLLA solution with PVA solution. The middle layer was made by blending PLLA solution with a mixture of PVA and Acetaminophen in de-ionized …

Drug Loaded Polymeric Blends For Developing Vascular Stents, Anup C. Dasnurkar

Bioengineering Theses - Archive

In-stent restenosis and neo-intimal hyperplasia are long-term limitations of metallic stents. Local delivery of medications to transluminal angioplasty sites to prevent restenosis is receiving worldwide attention. Development of localized application of antiproliferative agents, and gene therapy via bio-degradable coatings on metallic substrates proved to be successful in reducing restenosis but was limited by the problems of limited drug load, etc. The presence of a foreign object for a long period of time may lead to the further narrowing of the treated lesion. The rationale for usage of bioresorbable drug eluting stents is the ability to store large quantities of drug …

Development Of An In-Vitro Assay For Neurotrophin-Induced Segregation Of Nociceptive And Proprioceptive Sensory Axons, Ebrahim Shabbir Bengali

Bioengineering Theses - Archive

Peripheral nerves have the capacity for regeneration and if properly repaired, axon extensions can regenerate even across gaps caused by peripheral nerve loss. Complete functional recovery after gap injury repair remains suboptimal due to the erroneous pathways taken by the regenerating axons leading to aberrant target innervation. A segregation of axonal types can facilitate efficient target direction and innervation leading to improved functional recovery. Novel two-dimensional and three-dimensional Y-shaped assays were developed to test whether the nociceptive and proprioceptive sensory axons from the dorsal root ganglia could be segregated through specific neurotrophin inducement; namely NGF and NT-3 respectively. A large …

Development Of Targeting Nanoparticles Mimicking The Adhesive Properties Of Platelets, Arthur Lin

Bioengineering Theses - Archive

The development of biodegradable nanoparticles as drug delivery vehicles presents an improved avenue for intracellular targeted drug delivery. Biodegradable nanoparticles have demonstrated an ability to provide controllable, sustained drug release in vitro. However, in vivo studies have shown that nanoparticles are not effective at adhering to vascular walls under shear stress. The purpose of this study was to investigate methods to improve cellular uptake and targeting of nanoparticles in activated or inflamed endothelial cells (ECs) under fluid shear stress and to determine whether the material properties of a biodegradable polymer, poly (lactic-co-glycolic) acid (PLGA), affected cellular uptake. The hypothesis for …

Vegetative Treatment Systems For Open Lot Runoff: Review Of Literature, Richard K. Koelsch, Jeffrey Lorimer, Kyle Mankin

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

Runoff from open lot livestock systems (beef and dairy) defined as Concentrated Animal Feeding Operations (CAFO) must be controlled by systems designed and managed to prevent the release of manure-contaminated runoff for storms equal to or less than a 25-year, 24-hour design storm. This performance standard has been attained for open lot systems with some combination of clean water diversion, settling basins, runoff collection ponds and irrigation systems (baseline system).

An alternative approach is to rely on overland flow and infiltration into cropland with perennial forage or grasses for treatment of open lot runoff. Such vegetative systems have been researched …

Novel Preparation Of Polymeric Scaffolds For Tissue Engineering Using Phase Separation With Protein Microbubble Incorporation, Ashwin Nair

Bioengineering Theses - Archive

Poly (lactic-co-glycolic acid) (PLGA) has been extensively used as a biodegradable and porous tissue scaffold due to their biocompatibility and degradability. Several techniques have been developed for the fabrication of polymeric scaffolds but they all have some limitation or the other which has in turn hampered the growth of cells seeded on them. Salt leached scaffolds have good porosity and large pores but poor mechanical strength and the problem of residual salt even after leaching. Similarly gas foaming scaffolds have shown large pores but poor interconnection with residual ammonium salts. Other methods like thermally induced phase separation and fiber bonding …

Use Of Near Infrared And Visible Spectroscopies To Determine Optical Properties Of Rat Nervous System, Harsha Radhakrishnan

Bioengineering Theses - Archive

Changes to the anatomical or physiological structure of the neuronal circuitry are known to produce a change in the optical properties of the tissue under investigation. The goal of this thesis is to determine changes in the light scattering and hemoglobin oxygen saturation in three cases: (i) a normal spinal cord, (ii) demyelinated sciatic nerve, and (iii) spinal cord under neuronal activity induced by peripheral electrical stimulation. We hypothesize that (i) nerve demyelination or degeneration would result in a decrease in light scattering and hemoglobin oxygen saturation and (ii) peripheral electrical stimulation would show an increase in light scattering and …

99mTc-Labeled C2a Domain Of Synaptotagmin I As A Target-Specific Molecular Probe For Noninvasive Imaging Of Acute Myocardial Infarction, Ming Zhao, Xiaoguang Zhu, Shundong Ji, Jundong Zhou, Kutlan S. Ozker, Wei Fang, Robert C. Molthen, Robert S. Hellman

Biomedical Engineering Faculty Research and Publications

Abstract: The exposure of phosphatidylserine (PtdS) is a common molecular marker for both apoptosis and necrosis and enables the simultaneous detection of these distinct modes of cell death. Our aim was to develop a radiotracer based on the PtdS-binding activity of the C2A domain of synaptotagmin I and assess ^99mTc-C2A-GST (GST is glutathione S-transferase) using a reperfused acute myocardial infarction (AMI) rat model. Methods: The binding of C2A-GST toward apoptosis and necrosis was validated in vitro. After labeling with ^99mTc via 2-iminothiolane thiolation, radiochemical purity and radiostability were tested. Pharmacokinetics and biodistribution were studied in healthy rats. …

Yield Response Of Corn To Deficit Irrigation In A Semiarid Climate, José O. Payero, Steven R. Melvin, Suat Irmak, David D. Tarkalson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Irrigation water supplies are decreasing in many areas of the U.S. Great Plains, which is requiring many farmers to con¬sider deficit-irrigating corn (Zea mays L.) or growing crops like winter wheat (Triticum aestivum L.) that require less water, but that are less profitable. The objectives of this study were to: (1) quantify the yield response of corn to deficit irrigation, and (2) determine which of several seasonal water variables correlated best to corn yield in a semiarid climate. Eight (T1–T8) and nine (T1–T9) deficit-irrigated treatments (including dryland), were compared in 2003 and 2004 in North Platte, Nebraska. The …

Economics Of Manure Phosphorus Distribution From Beef Feeding Operations, William F. Kissinger, Raymond E. Massey, Richard K. Koelsch, Galen E. Erickson

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

An economic model was developed to evaluate cost and value of manure distribution. Feedlots ranging in size from 2,500 head to 25,000 head one-time capacities were used as case studies to calculate excretion amounts from cattle fed diets with a range of phosphorus. Diet P and subsequent costs of distributing the manure were used to analyze the corresponding costs of manure distribution, in addition to determining the required available land needed to be in compliance with a nutrient management plan based on utilization of manure P by the crops grown.

The model illustrated when animals are fed diets of increasing …

National Livestock And Poultry Environmental Learning Center, Richard K. Koelsch, Mark Risse, Joe Harrison, Jill Heemstra, Frank Humenik

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

This paper describes a new national initiative to improve the delivery of science-based information to non-research customers. The vision of the Livestock and Poultry Environmental Learning Center is to provide individuals involved in public policy issues, animal production, and delivery of technical services for confined animal systems with on-demand access to the nation’s best science-based resources that is responsive to priority and emerging environmental issues associated with animal agriculture. This paper describes the implementation plans for this project.

Molecular Modeling Of Proteins And Peptides Related To Cell Attachment In Vivo And In Vitro, Wanhua Zhao

Doctoral Dissertations

Polypeptides constitute half of the dry mass of the cell, they form the bulk of the extracellular matrix (ECM), and they are a common element of extra- and intracellular signaling pathways. There is increasing interest in the development of computational methods in polypeptide and protein engineering on all length scales. This research concerns the development of computational methods for study of polypeptide interactions related to cell attachment in vivo and in vitro.

Polypeptides are inherently biocompatible, and an astronomical range of unique sequences can be designed and realized in massive quantities by modern methods of synthesis and purification. These …

Temporal Calcium Response Of Jurkat Cells To Nanosecond Pulsed Electric Fields, Shaka Shakar Scarlett

Electrical & Computer Engineering Theses & Dissertations

Nanosecond pulsed electric fields (nsPEF) of megavolt per meter field strengths can interact with subcellular structures [1] and consequently trigger a variety of biological events. The exposure can induce apoptosis, as well as an array of differential "sub-lethal effects." One of the most sensitive and immediate responses is the increase in intracellular calcium concentration in pulsed cells [2], [3][4].We investigated the response of Jurkat cells (a human leukemic cell line) to nsPEFs of 60 ns duration and field strengths from 25 tol00 kV/cm. The development of the induced calcium response in individual cells was studied by spinning-disc confocal microscopy with …

Critical Computational Aspects Of Near Infrared Circular Tomographic Imaging: Analysis Of Measurement Number, Mesh Resolution And Reconstruction Basis, Phaneendra K. Yalavarthy, Hamid Dehghani, Brian W. Pogue, Keit D. Paulsen

Dartmouth Scholarship

The image resolution and contrast in Near-Infrared (NIR) tomographic image reconstruction are affected by parameters such as the number of boundary measurements, the mesh resolution in the forward calculation and the reconstruction basis. Increasing the number of measurements tends to make the sensitivity of the domain more uniform reducing the hypersensitivity at the boundary. Using singular-value decomposition (SVD) and reconstructed images, it is shown that the numbers of 16 or 24 fibers are sufficient for imaging the 2D circular domain for the case of 1% noise in the data. The number of useful singular values increases as the logarithm of …

Cosmm: An Undergraduate Laboratory For Engineering And Manufacturing Complex, Organic Shapes Using Nature As A Template, Daniel Walsh, Lanny Griffin, Robert Crockett

Biomedical Engineering

No abstract provided.

Alterations In Regional Vascular Geometry Produced By Theoretical Stent Implantation Influence Distributions Of Wall Shear Stress: Analysis Of A Curved Coronary Artery Using 3d Computational Fluid Dynamics Modeling, John F. Ladisa, Lars E. Olson, Douglas Anthony Hettrick, David C. Warltier, Judy R. Kersten, Paul S. Pagel

Biomedical Engineering Faculty Research and Publications

Background

The success of stent implantation in the restoration of blood flow through areas of vascular narrowing is limited by restenosis. Several recent studies have suggested that the local geometric environment created by a deployed stent may influence regional blood flow characteristics and alter distributions of wall shear stress (WSS) after implantation, thereby rendering specific areas of the vessel wall more susceptible to neointimal hyperplasia and restenosis. Stents are most frequently implanted in curved vessels such as the coronary arteries, but most computational studies examining blood flow patterns through stented vessels conducted to date use linear, cylindrical geometric models. It …

Dissociation Of Automatic And Strategic Lexical-Semantics: Functional Magnetic Resonance Imaging Evidence For Differing Roles Of Multiple Frontotemporal Regions, Brian T. Gold, David A. Balota, Sara J. Jones, David K. Powell, Charles D. Smith, Anders H. Andersen

Neuroscience Faculty Publications

Behavioral research has demonstrated three major components of the lexical-semantic processing system: automatic activation of semantic representations, strategic retrieval of semantic representations, and inhibition of competitors. However, these component processes are inherently conflated in explicit lexical-semantic decision tasks typically used in functional magnetic resonance imaging (fMRI) research. Here, we combine the logic of behavioral priming studies and the neurophysiological phenomenon of fMRI priming to dissociate the neural bases of automatic and strategic lexical-semantic processes across a series of three studies. A single lexical decision task was used in all studies, with stimulus onset asynchrony or linguistic relationship between prime and …

High-Resolution Thin-Film Device To Sense Texture By Touch, Vivek C. Maheshwari, Ravi F. Saraf

Ravi Saraf Publications

Touch (or tactile) sensors are gaining renewed interest as the level of sophistication in the application of minimum invasive surgery and humanoid robots increases. The spatial resolution of current large-area (greater than 1 cm²) tactile sensor lags by more than an order of magnitude compared with the human finger. By using metal and semiconducting nanoparticles, a ~100-nm-thick, large-area thin-film device is self-assembled such that the change in current density through the film and the electroluminescent light intensity are linearly proportional to the local stress. A stress image is obtained by pressing a copper grid and a United States …

The Effect Of Physiological Cyclic Stretch On The Cell Morphology, Cell Orientation And Protein Expression Of Endothelial Cells, V. Barron, Claire Brougham, K. Coghlan, C. Stenson-Cox, D. O'Mahoney, P.E. Mchugh

Articles

In vivo, endothelial cells are constantly exposed to pulsatile shear and tensile stresses. The main aim of this study was to design and build a physiological simulator, which reproduced homogenous strain profiles of the tensile strain experienced in vivo, and to investigate the effect of this cyclic tensile strain on the cell morphology, cell orientation and protein expression of endothelial cells. The biological response of human umbilical vein endothelial cells to a uniaxial cyclic stretch, in this newly developed simulator, was examined experimentally using immunohistostaining and confocal imaging and it was

found that the cells elongated and oriented at 58.9± …