Digital Commons Network^™

Surface Diffusion Of Adsorptive Species On Gold Nanoelectrodes, Bao-Fa Su, Wei Wang, Dong-Ping Zhan, Bin Ren, Zhong-Qun Tian

Journal of Electrochemistry

Gold nanoelectrodes were prepared successfully by a programmed laser puller. The Faraday adsorptions of oxygen and iodine, and the underpotential deposition of lead on the gold nanoelectrodes were investigated. The results showed that the active areas of nanoelectrodes were dramatically higher than their appearant geometry areas, which is caused by the surface diffusion of adsorptive species from the nanoscale gold/electrolyte interface to the adjacent gold surface.

Runx2 Protein Expression Utilizes The Runx2 P1 Promoter To Establish Osteoprogenitor Cell Number For Normal Bone Formation, Julie C. Liu, Christopher J. Lengner, Tripti Gaur, Yang Lou, Sadiq Hussain, Marci D. Jones, Brent Borodic, Jennifer L. Colby, Heather A. Steinman, Andre J. Van Wijnen, Janet L. Stein, Stephen N. Jones, Gary S. Stein, Jane B. Lian

School of Chemical Engineering Faculty Publications

The Runt-related transcription factor, Runx2, is essential for osteogenesis and is controlled by both distal (P1) and proximal (P2) promoters. To understand Runx2 function requires determination of the spatiotemporal activity of P1 and P2 to Runx2 protein production. We generated a mouse model in which the P1-derived transcript was replaced with a lacZ reporter allele, resulting in loss of P1-derived protein while simultaneously allowing discrimination between the activities of the two promoters. Loss of P1-driven expression causes developmental defects with cleidocranial dysplasia-like syndromes that persist in the postnatal skeleton. P1 activity is robust in preosteogenic mesenchyme and at the onset …

Water - Activities, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

The document contains activities for students in higher education. These activities are focused on water issues related to sustainability. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. Each activity includes a profile that indicates whether the activity involves direct or indirect information sources, whether the experience is doing or observing and whether it involves individual or group reflection. The profile also includes notes for faculty, an estimate of the time investment, a graphic of the developmental aims with respect to the six areas of …

Population, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of population issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

Population - Learning Objectives, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a list of learning objectives based on the framework of Fink’s taxonomy of significant learning: foundational knowledge, application, integration, human dimension, caring, and learning how to learn. It represents the aspirations for learning that the population is based on.

Water, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of water issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

An Objective Assessment Of Fetal Neurological Maturation Based On The Co-Variation Of Brain And Heart Rate Patterns, Srinivasan Vairavan

Theses and Dissertations

An in-utero neurological assessment would aid clinicians in an early detection of fetal neurological distress. However, accessing the fetal brain signal has remained a major challenge. With the advent of Superconducting Quantum Interference Device (SQUID) technology, magnetoencephalogram (MEG), is now an established technique for recording human brain activity. This technique is non-invasive and records the magnetic fields corresponding to electric currents generated by the neurons in the brain. Based on MEG technology, a first-of-a-kind device, named SARA (SQUID Array for Reproductive Assessment), was specifically designed and installed in the Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, …

Water - Learning Objectives, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a list of learning objectives based on the framework of Fink’s taxonomy of significant learning: foundational knowledge, application, integration, human dimension, caring, and learning how to learn. It represents the aspirations for learning that the water is based on.

Automation Of Orthodontic Wire Tester For Performing Three Point Bending Tests, Adithya Venkatesan

Master's Theses

Abstract

Understanding the biomechanical factors in orthodontics is important in order to improve the overall effectiveness of actual clinical treatment. An accurate method to study the threedimensional (3D) force systems and the resulting movements of teeth during orthodontic treatment is needed along with the understanding of the material properties of any orthodontic wire. Until recently, most of the orthodontic biomechanics literature was limited to twodimensional experimental studies. Recent advances in threedimensional computer modeling have also been developed but have been limited to the manual control of tooth movement. Overall, there is very little published evidence in the literature on the …

Fabrication And Characterization Of Zno/Cuo Core-Shell Nanowire Arrays, Kuo-Ting Liao

Master's Theses

Research into nanomaterials has become more and more popular because of their unique properties compared to bulk materials. Amongst various functional materials, zinc oxide (ZnO), with a direct electron energy band gap of 3.34 eV at room temperature, is an important optoelectronic material with an intrinsically n-type semiconducting property. However, to form a p-type ZnO semiconductor is still a challenge. Copper oxide (CuO), compared to ZnO, has a much smaller band gap, 1.2 eV, and shows an intrinsically p-type semiconducting property. It has been suggested that when CuO is alloyed with ZnO properly, a p-n semiconductor heterojunction can be formed …

Effect Of Prostaglandin E2 On Mechanical Stresses Applied By Mc3t3-E1 Osteoblast-Like Cells On A Soft Hydrogel Substrate, Abhijit Deb Roy

Master's Theses

Osteoblasts are sensitive to mechanical stimuli and release Prostaglandin E2 (PGE2) when exposed to a fluid shear stress. The exact mechanism by which these cells sense mechanical stress is not well established. A study of the stresses applied by the osteoblasts, under the influence of PGE2, on a hydrogel provided information regarding intercellular-communication via changes in the substrate surface pattern.

A digital image correlation program was developed using the Levenberg-Marquardt optimization algorithm to analyze images and compare the deformations between pairs of images. Comparisons of images before and after the addition of PE2 to the media showed differences in the …

Dissolved Organic Matter Characterization And Impact On Mercury Binding In An Urbanizing Watershed, Mykel Mendes

Master's Theses

Dissolved organic matter (DOM) is ubiquitous in aquatic ecosystems, interacting with and controlling the bioavailability and transport of mercury (Hg) and other trace metals through complexation. The complexation of ionic Hg (Hg²⁺) with DOM can either limit methyl mercury (MeHg) bioavailability or increase MeHg production by stimulating microbial growth. While substantial investigations have examined Hg-DOM interactions in forested ecosystems, little research has been conducted on the Hg-DOM relationship within an urbanized river setting subjected to various anthropogenic sources. The various runoff and pollutant sources vary in DOM quality and character. Three sources of organic matter from the North …

Glucose Biosensor Using Electrospun Mn2o3-Ag Nanofibers, Shan Huang

Master's Theses

The highly porous Mn₂O₃-Ag nanofibers were fabricated by a facile two-step procedure (electrospinning and calcination) and then employed as the immobilization matrix for glucose oxidase (GOD) to construct an amperometric glucose biosensor. A notable enhancement of direct electron transfer between GOD and the electrode is observed at the Mn₂O₃-Ag-GOD modified electrode with a fast electron transfer rate constant. The biosensor also shows fast response to glucose, high sensitivity (40.60 μA×mM^-1×cm^-2), low detection limit (1.73 µM at S/N=3), low K_m,app value and excellent selectivity. These results indicate that …

Plasmonic Nanogels With Robustly Tunable Optical Properties, Tao Cong, Satvik N. Wani, Georo Zhou, Elia Baszczuk, Radhakrishna Sureshkumar

Biomedical and Chemical Engineering - All Scholarship

Low viscosity fluids with tunable optical properties can be processed to manufacture thin film and interfaces for molecular detection, light trapping in photovoltaics and reconfigurable optofluidic devices. In this work, self-assembly in wormlike micelle solutions is used to uniformly distribute various metallic nanoparticles to produce stable suspensions with localized, multiple wavelength or broad-band optical properties. Their spectral response can be robustly modified by varying the species, concentration, size and/or shape of the nanoparticles. Structure, rheology and optical properties of these plasmonic nanogels as well as their potential applications to efficient photovoltaics design are discussed.

Fluid Structure And Boundary Slippage In Nanoscale Liquid Films, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

The book describes the concerted efforts of a large European research project and the achievements of additional leading research groups. The reported knowledge and expertise should support in the innovation and integration of often separated unitary processes. Sampling, cell lysis and DNA/RNA extraction, DNA hybridisation detection micro- and nanosensors, microfluidics, together also with computational modelling and risk assessment can be integrated in the framework of the current and evolving European regulations and needs. The development and uptake of molecular methods is revolutionizing the field of waterborne pathogens detection, commonly performed with time-consuming cultural methods. The molecular detection methods are enabling …

Ros-Drill Automation: Visual Feedback Control And Rotational Motion Tracking, Jhon F. Diaz

Master's Theses

ICSI (intra-cytoplasmic sperm injection) has attracted research interest from both biological and engineering groups. The technology is constantly evolving to perform this procedure with precision and speed. One such development is the contribution of this thesis. We focus on a relatively recent procedure called Ros-Drill^© (rotationally oscillating drill), of which the early versions have already been effectively utilized for the mice. In the first part, we present a procedure to automate a critical part of the operation: initiation of the rotational oscillation, Visual feedback is used to track the pipette tip. Predetermined species-specific penetration depth is successfully utilized …

Development Of Novel Bio/Nano Interfaces For Materials Science And Biomedical Applications, Carlee Ashley

Chemical and Biological Engineering ETDs

Virus-like particles (VLPs) of MS2 bacteriophage possess a variety of characteristics that enable their use in biomedical and materials science applications. MS2 VLPs are perfectly monodisperse and possess a highly regular periodic structure. Their protein capsids can be modified in precise locations via chemical conjugation or genetic display of peptides, and their interior volumes can be readily loaded with a variety of non-genomic materials by taking advantage of their ability to self-assemble in the presence of RNA and RNA-modified cargos. Using peptides identified by filamentous phage display, I have demonstrated the utility of MS2 VLPs as targeted nanocarriers capable of …

Mutant Alcohol Dehydrogenase Leads To Improved Ethanol Tolerance In Clostridium Thermocellum, Steven D. Brown, Adam M. Guss, Tatiana V. Karpinets, Jerry M. Parks

Dartmouth Scholarship

Clostridium thermocellum is a thermophilic, obligately anaerobic, Gram-positive bacterium that is a candidate microorganism for converting cellulosic biomass into ethanol through consolidated bioprocessing. Ethanol intolerance is an important metric in terms of process economics, and tolerance has often been described as a complex and likely multigenic trait for which complex gene interactions come into play. Here, we resequence the genome of an ethanol-tolerant mutant, show that the tolerant phenotype is primarily due to a mutated bifunctional acetaldehyde-CoA/alcohol dehydrogenase gene (adhE), hypothesize based on structural analysis that cofactor specificity may be affected, and confirm this hypothesis using enzyme assays. …

Transcriptome Sequencing Of The Blind Subterranean Mole Rat, Spalax Galili: Utility And Potential For The Discovery Of Novel Evolutionary Patterns, Assaf Malik, Abraham Korol, Sariel Hubner, Aaron Avivi, Alvaro Hernandez, Jyothi Thimmapuram, Shahjahan Ali, Mark Bond, Fabian Glaser, Arnon Paz

Cyber Center Publications

The blind subterranean mole rat (Spalax ehrenbergi superspecies) is a model animal for survival under extreme environments due to its ability to live in underground habitats under severe hypoxic stress and darkness. Here we report the transcriptome sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly of the sequences yielded over 51,000 isotigs with homology to ~12,000 mouse, rat or human genes. Based on these results, it was …

Simulation, Measurement And Image Analysis Of Corrosion Initiation And Growth Rate For Aluminum 2024 And Steel 304, Yan Fang

Theses and Dissertations

Abstract SIMULATION, MEASUREMENT AND IMAGE ANALYSIS OF CORROSION INITIATION AND GROWTH RATE OF ALUMIUM 2024 AND STEEL 304 By Yan Fang, MS A thesis submitted in partial fulfillment of the requirements for the degree of M.S. of Mechanical and Nuclear Engineering at Virginia Commonwealth University. Virginia Commonwealth University, 2011 Major Director: Dr. Brian Hinderliter, Ph. D Associate professor, Mechanical and Nuclear Engineering Time: 11 a.m. Place: Room E3210 Engineering East Hall Date: Friday August 12, 2011 Corrosion initiation and growth rate are important properties in maintaining structural integrity, especially for surface and pit corrosion of common infrastructure and transportation metals. …

Effect Of Particle Size, Binder Content And Heat Treatment On Mechanical Properties Of 13-93 Bioactive Glass Scaffolds, Krishna C. R. Kolan, Ming-Chuan Leu, Greg Hilmas, Mariano Garcia Velez

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Particle size, binder content and the post-processing schedule are important parameters that affect the microstructure, and, hence, the mechanical properties of parts produced using the indirect selective laser sintering process. 13-93 bioactive glass, with mean particle sizes ranging from 10 μm to 44 μm, is mixed with different amounts of stearic acid binder to fabricate green scaffolds. Through the design of the post-processing schedule, the time required for postprocessing the green scaffolds is reduced from the initial 80 hrs to 12 hrs. The compressive strength varies from 41 MPa for a part with~60% porosity to 157 MPa for a part …

Bio-Inspired Design Of Bipolar Plate Flow Fields For Polymer Electrolyte Membrane Fuel Cells, Nannan Guo, Ming-Chuan Leu, Maoliang Wu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The flow field of a bipolar plate distributes hydrogen and oxygen for polymer electrolyte membrane (PEM) fuel cells and removes the produced water from the fuel cells. It greatly influences the performance of fuel cells, especially regarding reduction of mass transport loss. Flow fields with good gas distribution and water removal capabilities reduce the mass transport loss, thus allowing higher power density. Inspired by natural structures such as veins in tree leaves and blood vessels in lungs, which efficiently feed nutrition from one central source to large areas and are capable of removing undesirable by-products, a mathematic model has been …

High Pressure Structural Studies On Nb5si3 Up To 26.2 Gpa, Brandon Stewart, Ravhi S. Kumar

Undergraduate Research Opportunities Program (UROP)

With the use of synchrotron techniques, we can better understand how crystalline structures behave under extreme conditions. This yields the opportunity to resolve complex crystal structures [1]. Here, we focus on the high pressure crystal structure of Nb5Si3. Refractory metal silicides are an important class of materials as they are used in high temperature applications such as turbines and aerospace modules. As an example, the performance of a jet engine is highly influenced by the maximum internal pressure and temperature possible. Obtaining higher levels of thrust is dependent upon the material's ability to remain structurally sound under extreme temperatures and …

Undergraduate Research Opportunities Program 2011, Nicholle Booker, University Of Nevada, Las Vegas

Undergraduate Research Opportunities Program (UROP)

Undergraduate Research Opportunities Program

On August 9, 2011 the UNLV College of Sciences will celebrate the accomplishments of undergraduate students participating in the Summer 2011 Undergraduate Research Opportunities Program (UROP) and the Research Experience For Undergraduates (REU) Program.

The public is invited to attend, beginning at 10:00 a.m.

Please join us to view student research posters. Student research topics include: biomedicine and human health, Nevada's fragile environment and ecosystems, climate change, stem cell research, microbiology, astrophysics, and many others.

Over 25 UNLV undergraduates and a cohort of 25 undergraduates selected from colleges and universities across the nation will mark the …

Methods Of Using Black Bear Parathyroid Hormone, Seth W. Donahue

Michigan Tech Patents

Black bear parathyroid hormone (PTH) and functional fragments thereof are provided. Also provided are methods of using black bear PTH and functional fragments for increasing cAMP in a bone-forming cell; reducing apoptosis in a boneforming cell; decreasing the ratio of expression levels of Bax protein to Bcl-2 protein in a bone-forming cell; increasing the expression level of one or more of a bone matrix protein, a transcriptional activator, or a transcriptional regulator in a bone-forming cell; enhancing bone mineral density, increasing bone mass, decreasing bone loss, or reducing the incidence of bone fractures, or any combination thereof, in a subject; …

Tailoring The Spectral Transmission Of Optofluidic Waveguides, Brian S. Phillips

Theses and Dissertations

Optofluidics is a relatively new and exciting field that includes the integration of optical waveguides into microfluidic platforms. The purpose of this field of study is to miniaturize previously developed optical systems used for biological and chemical analysis with the end goal of placing bench-top optics into microscopic packages. Mundane optical alignment and sample manipulation procedures would then be intrinsic to the platform and allow measurements to be completed quickly and with reduced human interaction. Biosensors based on AntiResonant Reflecting Optical Waveguides (ARROWs) consist of hollow-core waveguides used for fluid sample manipulation and analysis, as well as solid-core waveguides used …

Roles Of Particle-Wall And Particle-Particle Interactions In Highly Confined Suspensions Of Spherical Particles Being Sheared At Low Reynolds Numbers, Ashok S. Sangani, Andreas Acrivos, Philippe Peyla

Biomedical and Chemical Engineering - All Scholarship

The roles of particle-wall and particle-particle interactions are examined for suspensions of spherical particles in a viscous fluid being confined and sheared at low Reynolds numbers by two parallel walls moving with equal but opposite velocities. Both particle-wall and particle-particle interactions are shown to decrease the rotational velocity of the spheres, so that in the limit of vanishingly small gaps between the spheres and the walls, the spheres acquire a rotational slip relative to the walls. The presence of the walls also increases the particle stresslet and, therefore, the total viscous dissipation. In the limit of vanishingly small gaps, the …

Carotid Plaque Regression Following 6-Month Statin Therapy Assessed By 3t Cardiovascular Magnetic Resonance: Comparison With Ultrasound Intima Media Thickness, Raymond Q. Migrino, Mark Bowers, Leanne Harmann, Robert W. Prost, John F. Ladisa

Biomedical Engineering Faculty Research and Publications

Background

Cardiovascular magnetic resonance (CMR) allows volumetric carotid plaque measurement that has advantage over 2-dimensional ultrasound (US) intima-media thickness (IMT) in evaluating treatment response. We tested the hypothesis that 6-month statin treatment in patients with carotid plaque will lead to plaque regression when measured by 3 Tesla CMR but not by IMT.

Methods

Twenty-six subjects (67 ± 2 years, 7 females) with known carotid plaque (> 1.1 mm) and coronary or cerebrovascular atherosclerotic disease underwent 3T CMR (T1, T2, proton density and time of flight sequences) and US at baseline and following 6 months of statin therapy (6 had initiation, …

Electrochemical Synthesis Of Single Crystal Metal Nanowires, Nan Li

Master's Theses

Electrodeposition is an efficient and economical approach for template synthesis of one-dimensional (1D) nanostructured materials. Based on the porous membranes as templates during electrodeposition, metallic nanowires, nanorods, and nanotubes can overcome the geometrical restrictions to be inserted into the nanometric recesses with both diameter and length well controlled by tuning the size and thickness of the templates.

In this work, the morphology, growth rate and texture of copper nanowires prepared with templates were investigated by the controlled parameters in various experiments. Cu nanowire arrays with preferential orientations can be successfully synthesized into the Anodic Aluminum Oxide (AAO) templates with optimized …

Transcriptional Analysis Of Lactobacillus Brevis To N-Butanol And Ferulic Acid Responses, James Winkler, Katy Kao

Faculty Publications

BackgroundThe presence of anti-microbial phenolic compounds, such as the model compound ferulic acid, in biomass hydrolysates pose significant challenges to the widespread use of biomass in conjunction with whole cell biocatalysis or fermentation. Currently, these inhibitory compounds must be removed through additional downstream processing or sufficiently diluted to create environments suitable for most industrially important microbial strains. Simultaneously, product toxicity must also be overcome to allow for efficient production of next generation biofuels such as n-butanol, isopropanol, and others from these low cost feedstocks.Methodology and Principal FindingsThis study explores the high ferulic acid and n-butanol tolerance in Lactobacillus brevis, a …