Biomedical Engineering and Bioengineering Commons^™

In Vivo Magnetic Resonance Elastography Of Mesenchymally Derived Constructs, Shadi F. Othman, Evan T. Curtis, Huihui Xu

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The multidisciplinary field of tissue engineering (TE) aims to create biological substitutes to restore, maintain, or enhance the function of tissue or whole organs, in which the mechanical properties of replacements are critical to their structure and function. Several techniques have been investigated for measuring the mechanical properties of developing tissues and organs; however, current methods are destructive. The goal of this work is to apply high resolution Magnetic Resonance Elastography (μMRE) technique with 100 μm in-plane resolution to address a critical problem in TE: nondestructive monitoring and characterization of growing mesenchymal stem cells (MSCs)-based tissue engineered constructs. In this …

Effect Of Flow Gradient, Roi Size And Random Scatterer Movement During Speckle Size Estimation Based Blood Flow Measurement, Tiantian Xu, Greg Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Conventional blood flow velocity measurement using ultrasound is capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these Doppler-based methods are incapable of detecting blood flow in the direction normal to the ultrasound beam. An algorithm which measures the lateral blood flow velocity using speckle size change with scan velocity was developed in our previous studies. This method uses the apparent speckle size change that occurs when scatterers are moving relative to the spatial rate of A-line acquisition. Our previous results showed that the estimation error of this …

Using Thermally Coupled Reactive Distillation Columns In Biodiesel Production, Nghi Nguyen, Yaşar Demirel

Yaşar Demirel Publications

Production of ethyl dodecanoate (biodiesel) using lauric acid and methanol with a solid acid catalyst of sulfated zirconia is studied by using two distillation sequences. In the first sequence, the methanol recovery column follows the reactive distillation column. In the second sequence, the reactive distillation and methanol recovery columns are thermally coupled. Thermally coupled distillation sequences may consume less energy by allowing interconnecting vapor and liquid streams between the two columns to elminate reboiler or condenser or both. Here we study the thermally coupled side-stripper reactive distillation and eliminate the condenser of the reactive distillation column. Both the sequences are …

Energy And Climate Implications For Agricultural Nutrient Use Efficiency, Adam J. Liska, Richard K. Perrin

Adam Liska Papers

Energy and climate change are beginning to dominate the global political agenda and will drive policy formation that will shape the future of agriculture. Energy issues threaten national security and economic stability, as well as access to low-cost nutrient inputs for agriculture. Climate change has the potential to cause serious disruption to agricultural productivity. Paradoxically, nutrient use in agriculture to increase crop yields has the potential to negatively impact climate. This chapter will discuss recent and future energy and climate trends, the relationships between agricultural nutrient use efficiency and biofuels, and how global land limitations will shape agriculture in the …

Effect Of Distillers Grains Moisture And Inclusion Level In Livestock Diets On Greenhouse Gas Emissions In The Corn-Ethanol-Livestock Life Cycle, Virgil R. Bremer, Andrea K. Watson, Adam J. Liska, Galen Erickson, Kenneth Cassman, Kathryn J. Hanford, Terry Klopfenstein

Adam Liska Papers

A model was previously developed (Biofuel Energy Systems Simulator; www. bess.unl.edu) to predict greenhouse gas (GHG) emissions and net energy yield when ethanol is produced from corn. The model also predicts feedlot cattle, dairy cattle, and swine performance and feed replacement value of ethanol coproducts. Updated equations that predict performance of feedlot cattle fed 0 to 40% of dietary DM as corn wet (WDGS), modified (MDGS), or dry (DDGS) distillers grains plus solubles replacing dry-rolled and high-moisture corn were developed and incorporated into the model. Equations were derived from pen-level performance for 20 finishing studies evaluating WDGS, 4 evaluating MDGS, …

Fus Transgenic Rats Develop The Phenotypes Of Amyotrophic Lateral Sclerosis And Frontotemporal Lobar Degeneration, Cao Huang, Hongxia Zhou, Jianbin Tong, Han Chen, Yong-Jian Liu, Dian Wang, Xiaotao Wei, Xugang Xia

Nebraska Center for Biotechnology: Faculty and Staff Publications

Fused in Sarcoma (FUS) proteinopathy is a feature of frontotemporal lobar dementia (FTLD), and mutation of the fus gene segregates with FTLD and amyotrophic lateral sclerosis (ALS). To study the consequences of mutation in the fus gene, we created transgenic rats expressing the human fus gene with or without mutation. Overexpression of a mutant (R521C substitution), but not normal, human FUS induced progressive paralysis resembling ALS. Mutant FUS transgenic rats developed progressive paralysis secondary to degeneration of motor axons and displayed a substantial loss of neurons in the cortex and hippocampus. This neuronal loss was accompanied by ubiquitin aggregation and …

Comparative Manufacture And Cell-Based Delivery Of Antiretroviral Nanoformulations, Shantanu Balkundi, Ari S. Nowacek, Ram S. Veerubhotla, Han Chen, Andrea Martinez-Skinner, Upal Roy, R. Lee Mosley, Georgette Kanmogne, Xinming Liu, Alexander V. Kabanov, Tatiana Bronich, Joellyn Mcmillan, Howard E. Gendelman

Nebraska Center for Biotechnology: Faculty and Staff Publications

Nanoformulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz were manufactured by wet milling, homogenization or sonication with a variety of excipients. The chemical, biological, immune, virological, and toxicological properties of these formulations were compared using an established monocyte-derived macrophage scoring indicator system. Measurements of drug uptake, retention, release, and antiretroviral activity demonstrated differences amongst preparation methods. Interestingly, for drug cell targeting and antiretroviral responses the most significant difference among the particles was the drug itself. We posit that the choice of drug and formulation composition may ultimately affect clinical utility.

High Temperature Dilute Acid Pretreatment Of Coastal Bermuda Grass For Enzymatic Hydrolysis, Arthur P. Redding, Ziyu Wang, Deepak R. Keshwani, Jay J. Cheng

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Dilute sulfuric acid was used to pretreat coastal Bermuda grass at high temperature prior to enzymatic hydrolysis. After both pretreatment and enzymatic hydrolysis processes, the highest yield of total sugars (combined xylose and glucose) was 97% of the theoretical value. The prehydrolyzate liquor was analyzed for inhibitory compounds (furfural, hydroxymethylfurfural (HMF)) in order to assess potential risk for inhibition during the following fermentation. Accounting for the formation of the inhibitory compounds, a pretreatment with 1.2% acid at 140 °C for 30 min with a total sugar yield of 94% of the theoretical value may be more favorable for fermentation. From …

Pulmonary Particle Deposition In Relation To Age, Body Weight, And Species, Lisa M. Weber

Electronic Theses and Dissertations

As a result of dissimilarity in lung morphometry and physiological conditions, therapeutic aerosol particles deposit differently in humans of various ages and body weights. These particles also deposit differently in non-human species that are often utilized in inhalation and dosing studies. The focus of this work is to determine the optimal particle size and deposition (traditional efficiency and volume-weighted) of therapeutic particles in humans of both genders ranging in age from 3 months old to 21 years old and three non-human species (B6C3F₁ mouse, Long-Evans hooded rat, and Beagle dog). This study finds that in humans, both optimal …

Direct Forcing And Heating Immersed Boundary- Lattice Boltzmann Method For Arterial Wall Thermography, Oluyinka Olugbenga Bamiro

Dissertations

Vulnerable atherosclerotic plaques have high probability of rupture and are characterized by non-homogenous temperature along the arterial wall. The nonhomogeneous temperature is attributed to the accumulation of heat releasing inflammatory cells in the arterial wall. Rupture of the vulnerable plaque can lead to acute coronary syndrome and sudden cardiac death. Arterial wall thermography (AWT) can be applied to detect the presence of temperature hot spots along the arterial wall by using temperature measurement devices and provide an early detection of a vulnerable atherosclerotic plaque. AWT, however, is invasive in nature.

Computational fluid and heat transport models provide a more efficient …

Bone Tissue Quality Determination Of Mice Through A Novel Reference Point Indentation Technique, Matin Lendhey

Dissertations and Theses

"Bone strength deteriorates with age; which increases the susceptibility to fracture. Current clinical techniques for the estimation of bone strength are largely Bone Mineral Density (BMD) based. However, toughness, which is the ability to resist crack growth, plays a critical role in bones‟ fracture resistance. Traditionally, toughness measurements involve large samples, obviating their use clinically. Recent data suggest that a reference point indentation approach provides a novel, localized measure of toughness from whole bones. In the current research, we evaluated the sensitivity of this method to discriminate small known differences in fracture toughness that exist between inbred mouse strains with …

Development Of An Approach To Increase Drug Uptake To Bone Tumors Using Non-Invasive Mechanical Loading, Paolo E. Palacio

Dissertations and Theses

This thesis develops an approach to enhance drug delivery to bone tumors by implementing a non-invasive mechanical loading technique. An imaging protocol that characterizes the load-enhanced drug uptake is also presented. The long-term goal of this work is to develop a clinical protocol that enhances the delivery of therapeutic agents to bone tumors by utilizing load-bearing activity. This easy-to-implement approach could help increase drug uptake into the tumor interstitial fluid space as well as into tumor cells, thereby enhancing a drug's clinical effect while decreasing systemic drug dosage and unwanted side effects. This thesis details the process used to grow …

Effects Of Estrogen Loss On The Vascular Porosity In Rat Cortical Bone, Jessica D Levy

Dissertations and Theses

"Osteoporosis is a skeletal disease that currently affects 10 million Americans, and is characterized by low bone mass and increased skeletal fragility (National Osteoporosis Foundation, 2011). Estrogen loss, which begins during menopause, is the leading cause of osteoporosis in women. Recent research has focused on changes in cortical bone microporosity due to estrogen loss, which is important for bone health; load-induced interstitial fluid flow within the lacunar-canalicular porosity surrounding osteocytes is thought to play an important role in bone maintenance, while the vascular porosity provides a pressure relaxation mechanism for the fluid flow in the lacunar-canalicular porosity. Recent high-resolution micro-CT …

Transport Of Antibodies And Nanoparticles Across An In Vitro Blood-Brain Barrier, Lin Zhang

Dissertations and Theses

"The blood-brain barrier (BBB) is a dynamic interface between the blood circulation and the central nervous system (CNS). While it serves as a selective barrier to water and solutes to prevent the blood-borne toxins from entering into the brain tissue, it hinders the drug delivery to the CNS for the treatment of brain diseases. Recently therapeutic antibodies and a variety of drug-loaded nanoparticles (NPs) have been widely used to treat CNS disorders such as brain tumors, Alzheimer's disease and Parkinson's disease. To improve brain delivery efficacy of antibodies and NPs, it is necessary to quantify their transport parameters across the …

Evaluation Of A Novel Self-Assembled Nanocoating In Promoting Bone On-Growth And Apposition On Metal, Hani Ghazi

Dissertations and Theses

"Loosening of metal is the leading cause of clinical failures of orthopedic surgeries. A novel coating of self-assembled monolayer of phosphonate molecules (SAMP) that chemically enhances metallic surfaces by covalently bonding to their naturally occurring oxidized surfaces has been developed.1 The SAMP coating is chemically stable, and its in-vitro results showed that it promotes cell proliferation, osteoblast adhesion and enhances biological attachment to metal surfaces.1 The purpose of this study is to establish the efficacy of this novel chemical surface treatment in improving the fixation of metallic implants in both cortical and cancellous bone over a conventional untreated implant. We …

Proteomic Analysis Of Human Mesenchymal Stem Cell Aging During Serial Sub-Culture, Pawan Kc

Dissertations and Theses

"Human mesenchymal stem cells (hMSCs) hold great potential for clinical applications in regenerative medicine. However, hMSCs occur at a very low frequency in bone marrow so the clinical use as cellular therapeutics requires suitable techniques for isolation and expansion. Furthermore, these cells can be expanded in vitro for only limited passage numbers before they reach a senescent state. Previous studies have shown that long term culture of hMSCs results in the decrease in proliferation rates, changes in genomic expressions, increase in cell sizes, and other morphological changes. Currently the mechanisms of hMSC aging and biomarkers associated with it have not …

Analysis Of The Performance Of Peanut Fame In A Single Cylinder Idi Engine And Investigations Of Neat Methyl Ester Influence On Fuel Quality, Jeffery Lewis

College of Graduate Studies: Theses & Dissertations

Author's abstract: To meet evolving standards set forth by the U.S. EPA and U.S. Energy Policy it is necessary to consider a variety of feedstock for biofuels synthesis and to understand the role individual fatty acids contribute to the overall performance. It is the belief of the authors that excess peanut production would provide an excellent source for high quality biodiesel feedstock, and the complete property and combustion analysis of the fatty acid components will provide insight for future biofuel developments. The preliminary investigations of the project focused on the combustion performance and thermal efficiency of peanut FAME and its …

Development, Validation, And Application Of A Noninvasive Spinal Motion Measurement System, Shaun Kevin Stinton

University of Kentucky Doctoral Dissertations

Spontaneous vertebral fractures are a large and growing health care problem. Biomechanical factors, specifically, abnormal posture or gait‐related spinal motion may interact with age‐weakened bone to induce altered spinal biomechanics that in turn increase the likelihood of vertebral body fracture. This research takes steps towards the goal of reducing the number of vertebral fractures in two phases: 1) Validation of a noninvasive spinal motion measurement system in cadaver torsos and 2) Application of the measurement system in human subjects.

The cadaver study compared vertebral motion at 4 levels (T7,T12,L3,L5) as measured by adhesive skin markers versus motion measured by bone …

Role Of Hydrodynamic Behavior Of Dna Molecules In Dielectrophoretic Polarization Under The Action Of An Electric Field, Hui Zhao

Mechanical Engineering Faculty Research

A continuum model is developed to predict the dielectrophoretic polarizability of coiled DNA molecules under the action of an alternating current electric field. The model approximates the coiled DNA molecule as a charged porous spherical particle. The model explains the discrepancies among scaling laws of polarizability of different-sized DNA molecules with contour length and such discrepancies are attributed to different hydrodynamic behavior. With zero or one fitting parameter, theoretical predictions are in good agreement with various experimental data, even though in experiments there are some uncertainties in regard to certain parameters.

Distal Radioulnar Joint Biomechanics And Forearm Muscle Activity, Joseph Scott Bader

University of Kentucky Doctoral Dissertations

Optimal management of fractures, post-traumatic arthritis and instability of the distal radioulnar joint (DRUJ) requires an understanding of the forces existing across this joint as a function of the activities of daily living. However, such knowledge is currently incomplete. The goal of this research was to quantify the loads that occur at the DRUJ during forearm rotation and to determine the effect that individual muscles have on those loads.

Human and cadaver studies were used to analyze the shear (A-P), transverse (M-L) and resultant forces at the DRUJ and to determine the role that 15 individual muscles had on those …