Digital Commons Network^™

Engineering Biosensors For Short-Chain Alcohols, Yu Xia

McKelvey School of Engineering Graduate Student Theses & Dissertations

Biofuel is a promising substitute for fossil fuel and the research of biofuel production has been extensively conducted during the recent years. Great efforts have been made to create many types of the fuel production hosts. However, effective approaches for high specificity and high throughput screening of the fuel production strains are still lacking. The cellular stress response is one universal defense mechanism when a microbial cell is exposed to an unfavorable substance or environment. It triggers a series of downstream responses when a cell senses certain chemicals. Transcriptional factors are widely used in living organisms to regulate gene expression. …

Nanostructured Aluminum Oxide (Nao): Enhanced Fluorescence Imaging And Sensing, Xiang Li

Doctoral Dissertations

A new fluorescence enhancement technical platform based on nanostructured aluminum oxide (NAO) has been discovered. Experiments reveal that this new platform can enhance the fluorescence signals up to two or three orders of magnitude compared to a traditional glass substrate platform. In order to realize a large-scale arrayed fluorescence biosensing platform for high throughput applications, a rapid and cost-effective process has been developed to fabricate the micropatterned NAO of a variety of shapes. An optical characterization technology, by introducing UV light irradiance, has been found for the first time to determine if the NAO has been formed from Al and …

Particle Swarm Optimization Using Multiple Neighborhood Connectivity And Winner Take All Activation Applied To Biophysical Models Of Inferior Colliculus Neurons, Brandon S. Coventry

Open Access Theses

Age-related hearing loss is a prevalent neurological disorder, affecting as many as 63% of adults over the age of 70. The inability to hear and understand speech is a cause of much distress in aged individuals and is becoming a major public health concern as age-related hearing loss has also been correlated with other neurological disorders such as Alzheimer's dementia. The Inferior Colliculus (IC) is a major integrative auditory center, receiving excitatory and inhibitory inputs from several brainstem nuclei. This complex balance of excitation and inhibition gives rise to complex neural responses, which are measured in terms of firing rate …

Reverse Protein Engineering Of Firefly Luciferase, Kahler Bugtong, Skyler Herczeg, Abraham Munoz, Alexandra Obata

Bioengineering Senior Theses

Firefly luciferase is a bioluminescent protein commonly used as a bioluminescent tag in biological studies and applications. However, because the protein is fairly large in size, it is sometimes larger than the molecules it is intended to measure and is therefore not a sufficient tag in smaller applications. The active site of firely luciferase is also not well understood, making it difficult to engineer the protein without affecting its bioluminescent activity. In this paper, we discuss the experimental methods of Reverse Protein Engineering: a bioengineering technology that reduces the size of a protein while retaining its original function. This involves …

Bio Roll-Up: Self-Assembling Scaffolds For Tissue Engineering, Chase Austyn Brisbois

Nanoscale Science & Engineering (discontinued with class year 2014)

There is an unmet need for controlled, dynamic cell scaffolds that will generate 3-D monolayers of epithelial cells for medical research and tissue engineering. Here we describe a system that uses photoimageable and biocompatible HEMA-based hydrogel bilayers that self-assemble from 2-D substrates into 3-D tube-shaped structures. These structures are patterned on top of another layer that demonstrates an ability to anchor the assembled structure and control the direction and extent of selfassembly. Cell viability was determined by MTT assay which shows material components comparable with the positive control (80-110%). Finally, the masks used in the experiments herein were redesigned to …

Corrosion Assessment And Enhanced Biocompatibility Analysis Of Biodegradable Magnesium-Based Alloys, Luis Enrique Pompa

Theses and Dissertations - UTB/UTPA

Magnesium alloys have raised immense interest to many researchers because of its evolution as a new third generation material. Due to their biocompatibility, density, and mechanical properties, magnesium alloys are frequently reported as prospective biodegradable implant materials. Moreover, magnesium based alloys experience a natural phenomena to biodegrade in aqueous solutions due to its corrosive activity, which is excellent for orthopedic and cardiovascular applications. However, major concerns with such alloys are fast and non-uniform corrosion degradation. Controlling the degradation rate in the physiological environment determines the success of an implant. In this investigation, three grades of magnesium alloys: AZ31B, AZ91E and …

Inkjet Printing Of Three-Dimensional Vascular-Like Constructs From Cell Suspensions, Changxue Xu

All Dissertations

Inkjet printing has found an increasing number of biofabrication applications, specifically organ printing, which has been emerging as a promising solution to the organ donor shortage. While some studies have been conducted to investigate various engineering problems associated with DOD inkjet printing of biological material-based fluids, the pinch-off, the cell-laden droplet formation, the effects of electric field on droplet formation, and challenges in 3D vascular-like construct fabrication haven't been systematically investigated. The objective of this study is to investigate the pinch-off, the cell-laden droplet formation, the effects of electric field on droplet formation, and manufacturing challenges during fabrication using DOD …

Development Of A Light-Powered Microstructure : Enhancing Thermal Actuation With Near-Infrared Absorbent Gold Nanoparticles., Thomas Matthew Lucas

Electronic Theses and Dissertations

Development of microscale actuating technologies has considerably added to the toolset for interacting with natural components at the cellular level. Small-scale actuators and switches have potential in areas such as microscale pumping and particle manipulation. Thermal actuation has been used with asymmetric geometry to create large deflections with high force relative to electrostatically driven systems. However, many thermally based techniques require a physical connection for power and operate outside the temperature range conducive for biological studies and medical applications. The work presented here describes the design of an out-of-plane bistable switch that responds to near-infrared light with wavelength-specific response. In …

Understanding The Influence Of Interfacial Chemistry In Core, Core/Shell And Core/Shell/Shell Quantum Dots On Their Fluorescence Properties, Omondi Bernard Omogo

Graduate Theses and Dissertations

Colloidal semiconductor nanocrystals (quantum dots) have received a great deal of attention due to their superior size tunable properties and promising applications in many areas. Some of the most practical areas of their applications include light emitting diodes (LED), photovoltaic and biological studies. Synthetic methods of these crystals is becoming more established with new strategies being reported every now and then. However, quantitative studies connecting the processes at the interface, namely core-ligand, core-shell and shell-shells, to the overall quantum dots fluorescence properties are not well understood. Specifically for cores, relating surface-atoms interactions, solvents, ligands nature, density and functional groups on …

A Novel Three Degree-Of-Freedoms Oscillation System Of Insect Flapping Wings, Yi Qin

Open Access Theses

We propose an oscillation system to replicate the dynamic behavior of flapping wings, inspired by insect flight muscles. In particular, we study the flight of the fruit fly Drosophila virilis . We model the wing as a rigid body with three degree-of-freedom, described by three Euler angles: the stroke angle, the rotation angle and the deviation angle. Insect flight muscles are separated into two types: power muscles and control muscles. One actuator and one torsional spring at the stroke angle act as the power muscles. Two torsional springs at the rotation angle and the deviation angle mimic the control muscles. …

Submicron-Resolution Photoacoustic Microscopy Of Endogenous Light-Absorbing Biomolecules, Chi Zhang

All Theses and Dissertations (ETDs)

Photoacoustic imaging in biomedicine has the unique advantage of probing endogenous light absorbers at various length scales with a 100% relative sensitivity. Among the several modalities of photoacoustic imaging, optical-resolution photoacoustic microscopy (OR-PAM) can achieve high spatial resolution, on the order of optical wavelength, at <1 mm depth in biological tissue (the optical ballistic regime). OR-PAM has been applied successfully to structural and functional imaging of blood vasculature and red blood cells in vivo. Any molecules which absorb sufficient light at certain wavelengths can potentially be imaged by PAM. Compared with pure optical imaging, which typically targets fluorescent markers, label-free PAM avoids the major concerns that the fluorescent labeling probes may disturb the function of biomolecules and may have an insufficient density. This dissertation aims to advance label-free OR-PAM to the subcellular scale.

The first part of this dissertation describes the technological advancement of PAM yielding high spatial resolution in 3D. The lateral resolution was improved by using optical objectives with high numerical apertures for optical focusing. The axial resolution was improved by using broadband ultrasonic transducers for ultrasound detection. We achieved 220 nm lateral resolution in transmission …

The Brain’S Response To Physical Activity Studied With Fmri, Ren Weidman, Dr. Travis Oliphant

Journal of Undergraduate Research

In recent years the fields of medicine and physiological research have made many advancements as a result of application of technology. One example of this is the device known as the Magnetic Resonance Imaging machine (MRI). MRI machines use innovative methods based on principles of physics and electronics to effectively attain a cross-sectional view of the human body. The MRI machine emits an electromagnetic field in the presence of a static field to manipulate the nuclear spin of hydrogen atoms in the body. The received signal can then be interpreted and reconstructed to plot a picture of the section examined. …

Engineering Research Review 2014, Office Of Engineering Research

Engineering Research Review

Contents:
[Page] 2 Bioinformatics help scientists make sense of genomic data
[Page] 4 Maps help public health officials fight malaria, West Nile Virus
[Page] 6 North Dakota-South Dakota engineers develop materials, components for solid state cell phone
[Page] 8 Statisticians uncover major reason behind cancer survivors’ choices
[Page] 10 Crash reporting helps reduce fatalities, improve roads on tribal lands
[Page] 12 Operations management expert, Mayo Clinic researcher help improve health-care delivery for patients with blood poisoning
[Page] 14 ISEE supports grant development
[Page] 16 Three engineering researchers receive awards
[Page] 17 Grantswinship awards recognize research funding

Design And Evaluation Of A Propulsion System For Small, Compact, Low-Speed Maneuvering Underwater Vehicles, Florence M. Mbithi

Electronic Theses and Dissertations

Underwater vehicles used to perform precision inspection and non-destructive evaluation in tightly constrained or delicate underwater environments must be small, have low-speed maneuverability and a smooth streamlined outer shape with no appendages. In this thesis, the design and analysis of a new propulsion system for such underwater vehicles is presented. It consists primarily of a syringe and a plunger driven by a linear actuator and uses different inflow and outflow nozzles to provide continuous propulsive force. A prototype of the proposed propulsion mechanism is built and tested. The practical utility and potential efficacy of the system is demonstrated and assessed …

Oppositional Biogeography-Based Optimization, Mehmet Ergezer

ETD Archive

This dissertation outlines a novel variation of biogeography-based optimization (BBO), which is an evolutionary algorithm (EA) developed for global optimization. The new algorithm employs opposition-based learning (OBL) alongside BBO migration to create oppositional BBO (OB BO). Additionally, a new opposition method named quasi-reflection is introduced. Quasireflection is based on opposite numbers theory and we mathematically prove that it has the highest expected probability of being closer to the problem solution among all OBL methods that we explore. Performance of quasi-opposition is validated by mathematical analysis for a single-dimensional problem and by simulations for higher dimensions. Experiments are performed on benchmark …

Computational Investigation On The Structural Properties Of Neurofilaments And Their Sidearms, Lakshmi Jayanthi

Wayne State University Dissertations

Neurofilaments (NFs) are class IV intermediate filaments, abundantly found in the large myelinated axons. They are the key determinants of axonal diameter and consequently the nerve conduction properties. On the other hand, abnormal NF accumulation has been the hallmark of debilitating neurodegenerative disorders. NF compaction is also one of the pathological manifestations of traumatic axonal Injury. However, the exact relation between the disorganized NFs and the etiology of the neurodegenerative disorders is yet to be fully understood. NFs are assembled from three subunits: Low (NFL), Medium (NFM) and Heavy (NFH). These subunits are characterized by a common alpha helical rod …

Chronic Toxicity Of Nano Metallics On Red Swamp Crayfish (Procambarus Clarkii) In Laboratory And Mesocosm Studies, Jake Andrew Farlow

LSU Master's Theses

Nanotechnology has become integrated in commercial, industrial and medical products, and its use has grown exponentially in the past several years. Although potential applications of nanoparticles (NPs) are numerous, concerns about their water quality, environmental, and human health impacts remain unclear. Crayfish are ubiquitous to streams and wetland habitats, are used as a food source, and inhabit areas that could be impacted by water quality issues. Numerous studies have been conducted on the toxicity of various classes of agricultural pesticides and oils to crayfish (Procambarus clarkii) as a non-target organism. However, there is little evidence published on chronic toxicity of …

Physical Stability Of Poly (Lactic-Co-Glycolic Acid) And Plga/Chitosan Nanoparticles And Chemical Stability Of Entrapped Alpha-Tocopherol And Lutein, Meocha Whaley

LSU Master's Theses

The published benefits of polymeric nanoparticles as a system for antioxidant delivery have encompassed topics of improved oral delivery, bioavailability, and modified release to name a few. Generally accepted as safe polymers Poly(lactic-coglycolic acid) and the mucoadhesive chitosan were selected to entrap alpha-tocopherol and lutein. This study proposed to assess the physical stability of PLGA and Chi/PLGA nanoparticles with entrapped bioactives in varying biological suspension medias ( water, pbs, hbss and cell media). Also, to assess the chemical stability of the entrapped antioxidants lutein and alpha-tocopherol within the same media as deemed relevant for in-vitro and and in-vivo studies. Of …

Development Of Confocal Imaging Techniques For Probing Interfacial Dynamics In Microscale, Gas-Liquid, Two-Phase Flow, Joseph E. Hernandez

Dissertations, Master's Theses and Master's Reports - Open

Micro-scale, two-phase flow is found in a variety of devices such as Lab-on-a-chip, bio-chips, micro-heat exchangers, and fuel cells. Knowledge of the fluid behavior near the dynamic gas-liquid interface is required for developing accurate predictive models. Light is distorted near a curved gas-liquid interface preventing accurate measurement of interfacial shape and internal liquid velocities. This research focused on the development of experimental methods designed to isolate and probe dynamic liquid films and measure velocity fields near a moving gas-liquid interface. A high-speed, reflectance, swept-field confocal (RSFC) imaging system was developed for imaging near curved surfaces.

Experimental studies of dynamic gas-liquid …

Layered Long Term Co-Culture Of Hepatocytes And Endothelial Cells On A Transwell Membrane: Toward Engineering The Liver Sinusoid, Young Bok (Abraham) Kang, Siddhartha Rawat, Joseph Cirillo, Michael Bouchard, Hongseok (Moses) Noh

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This paper presents a novel liver model that mimics the liver sinusoid where most liver activities occur. A key aspect of our current liver model is a layered co-culture of primary rat hepatocytes (PRHs) and primary rat liver sinusoidal endothelial cells (LSECs) or bovine aortic endothelial cells (BAECs) on a transwell membrane. When a layered co-culture was attempted with a thin matrigel layer placed between hepatocytes and endothelial cells to mimic the Space of Disse, the cells did not form completely separated monolayers. However, when hepatocytes and endothelial cells were cultured on the opposite sides of a transwell membrane, PRHs …

Design Of Engineered Biomaterial Architectures Through Natural Silk Proteins, Nicholas Kurland

Theses and Dissertations

Silk proteins have provided a source of unique and versatile building blocks in the fabrication of biomedical devices for addressing a range of applications. Critical to advancing this field is the ability to establish an understanding of these proteins in their native and engineered states as well as in developing scalable processing strategies, which can fully exploit or enhance the stability, structure, and functionality of the two constituent proteins, silk fibroin and sericin. The research outlined in this dissertation focuses on the evolution in architecture and capability of silks, to effectively position a functionally-diverse, renewable class of silk materials within …

Multi-Factorial Stability Study Of Metabolites, Ruijun Zheng, John A. Morgan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Previous research done on metabolites has found that high energy compounds like adenosine triphosphate(ATP), nicotinamide adenine dinucleotide phosphate reduced (NADPH) or nicotinamide adenine dinucleotide reduced (NADH) are unstable in cell extracts at relatively high temperature and acidic condition. The multifactorial stability study of metabolites enables us to verify the best condition of storage for these energy compounds and sugar phosphates, as well as to strengthen the understanding of metabolism in biological study. As the most solvents for high performance liquid chromatography (HPLC) are acidic and unfavorable for these energy compounds, it is necessary to perform a detailed study about …

Altered Cholesterol Metabolism In Human Cancers Unraveled By Label-Free Spectroscopic Imaging, Shuhua Yue

Open Access Dissertations

Despite tremendous scientific achievements, cancer remains the second leading cause of death in the United States. Metabolic reprogramming has been increasingly recognized as a core hallmark of cancer. My dissertation work identified novel diagnostic markers and therapeutic targets for human cancers through the study of cholesterol in cancer cells.

Enabled by label-free Raman spectromicroscopy, we performed the first quantitative analysis of lipogenesis at single cell level in human patient cancerous tissues. Our imaging data revealed an unexpected, aberrant accumulation of esterified cholesterol in lipid droplets of high-grade prostate cancer and metastases, but not in normal prostate, benign prostatic hyperplasia, or …

Automated Methods To Determine Electrospun Fiber Alignment And Diameter Using The Radon Transform, Nicholas J. Schaub, Sean J. Kirkpatrick, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Recent evidence demonstrates the ability to change cell function by altering the physical properties of electro spun scaffolds, but many studies still do not characterize electro spun fiber alignment and diameter. To aid in the reporting of these crucial properties, we demonstrate two methods of quantifying electro spun fiber alignment with one method capable of determining electro spun fiber diameter. The first method assesses fiber alignment in a scanning electron microscopy image using the Radon Transform (RT) to calculate the entropy of the fibers in the image. The RT entropy method was more sensitive than a commonly used Fast Fourier …

Scitech Book News Reviews, Susan Fingerman

Sci-Tech News

No abstract provided.

Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan

Theses and Dissertations

Glucose and other carbohydrates are some of the most abundant renewable energy sources in the world. The oxidation of carbohydrates in a fuel cell allows their chemical energy to be converted directly into electrical energy. Viologen has been indentified and shows promising ability as an electron-transfer catalyst or mediator for carbohydrate oxidation in an alkaline carbohydrate fuel cell. Building on the previous results, the objective of this work was to develop an immobilization chemistry of viologen onto an electrode and to investigate the catalytic activity for carbohydrate oxidation in direct carbohydrate fuel cells.The immobilization was achieved by electropolymerizing a novel …

Layered Hepatocytes And Endothelial Cells On A Transwell Membrane: Toward Engineering The Liver Sinusoid, Young Bok (Abraham) Kang, Joseph Cirillo, Siddhartha Rawat, Michael Bouchard, Hongseok (Moses) Noh

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This paper presents a novel liver model that mimics the liver sinusoid where most liver activities occur. A key aspect of our current liver model is a layered co-culture of primary rat hepatocytes (PRHs) and primary rat liver sinusoidal endothelial cells (LSECs) or bovine aortic endothelial cells (BAECs) on a transwell membrane. When a layered co-culture was attempted with a thin Matrigel layer placed between hepatocytes and endothelial cells to mimic the space of Disse, the cells did not form completely separated monolayers. However, when hepatocytes and endothelial cells were cultured on the opposite sides of a transwell membrane, PRHs …

Techno-Economic And Fluid Dynamics Analysis For Growing Microalgae With The Intent Of Producing Biofuel Using A System Model, Leah R. Raffaeli

Electronic Theses and Dissertations

Techno-economic and systems studies on microalgal growth scenarios to date are abbreviated and missing a number of important variables. By including these variables in a detailed model integrating biology, chemistry, engineering, and financial aspects, a more defined systems analysis is possible. Through optimizing the model productivity based on the resulting net profit, the system analysis results in a more accurate assessment of environmental and economic sustainability of specific algal growth scenarios. Photobioreactor algal growth scenario optimization in the system model has resulted in realistic engineering design requirements based on algal growth requirements and fluid dynamics analysis. Results show feasibility for …

A Distributed Local-Leg Feedback Algorithm For Robust Walking On Uneven Terrain, Mayur Ramakant Palankar

USF Tampa Graduate Theses and Dissertations

Legged animals can traverse significantly more of the Earth's land mass than man-made wheeled and tracked vehicles~\cite{Anonymous67}. Their impressive mobility is largely due to multiple dexterous legs and the robust algorithms that coordinate and control them. A legged animal such as a squirrel can exhibit multiple locomotion modes such as walking, running and jumping and also multiple gaits or leg phase timings within each mode. A robot that could mimic this level of robust locomotion would be highly useful for planetary exploration, military reconnaissance, and time-critical search and rescue in cluttered or collapsed buildings.

A number of biological studies on …

Effect Of Doping On Β-Tricalcium Phosphate Bioresorbable Bulk Material And Thin Film Coatings, Suhaila Abdalla

Dissertations

Magnesium has emerged as a revolutionary biodegradable metal for use as an orthopedic material, it has several advantages over the permanent metallic materials currently in use, including eliminating the effects of stress shielding, improving biocompatibility and degradation properties, thus removing the requirement of a second surgery for implant removal. Due to the rapid degradation of magnesium, it is necessary to control the corrosion rates of the materials to match the rates of bone healing. This dissertation reports on the effect of doping on the properties of β-tricalcium phosphate (β-TCP). It also reports on its application as a thin film coating …