Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Clemson University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2971 - 3000 of 5973

Full-Text Articles in Entire DC Network

Ecm Stabilization Strategies For Bioprosthetic Heart Valves For Improved Durability, Devanathan Raghavan Dec 2008

Ecm Stabilization Strategies For Bioprosthetic Heart Valves For Improved Durability, Devanathan Raghavan

All Dissertations

Abstract
Approximately 85,000 heart valve replacement surgeries are performed every year in United States and about 300,000 surgeries worldwide. It is estimated that half of them are mechanical valve replacements and the other half bioprosthetic valve replacements. The use of bioprosthetic heart valves is slowly increasing. Bioprosthetic heart valves are made from porcine aortic valves or bovine pericardium. Commercially these bioprostheses are currently crosslinked using glutaraldehyde (GLUT) to prevent tissue degradation and reduce tissue antigenicity. GLUT crosslinks these bioprostheses by stabilizing the collagen present in the tissue via a Schiff base reaction of the aldehyde with the hydroxylysine / lysine …

Go to article

Novel Lactide Derived Polymers; Synthesis, Properties And Applications, Dahlia Haynes Dec 2008

Novel Lactide Derived Polymers; Synthesis, Properties And Applications, Dahlia Haynes

All Dissertations

This dissertation primarily encompasses the synthesis, characterization, properties and discussion of applications for lactide derived polymers. The methodology focuses on altering polylactide's (PLA's) dynamic and physical properties increasing its broad market utility in both traditional and non-traditional applications. The fundamentals of this work include understanding and enhancing the polymer chemistry and materials related processes through the use of copolymerization, fluorination, composite chemistry and materials science.
The first chapter discusses the important of this research with emphasis on current world issues that focuses on the feasibility of renewable resources and sustainability implementation. Modification of renewable resource materials like lactic acid is …

Go to article

'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma Dec 2008

'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma

All Dissertations

This research focuses on fabricating blends and composites from natural polymers especially from proteins and natural epoxy, and describing the properties of plastics made from them. Specifically, plastic samples from partially denatured feathermeal and bloodmeal proteins, derived from the animal co-products (rendering) industry, were successfully produced through a compression molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. Therefore, this study explored blending methods for …

Go to article

Characterization Of Vascular Smooth Muscle Cell Mechanical And Frictional Properties Using Atomic Force Microscopy, Jason Hemmer Dec 2008

Characterization Of Vascular Smooth Muscle Cell Mechanical And Frictional Properties Using Atomic Force Microscopy, Jason Hemmer

All Dissertations

A working hypothesis within the Laboratory of Vascular Research is that mechanical loading on vascular smooth muscle cells (VSMCs), especially due to solid contact from endovascular devices, contributes to the development of restenosis. In order to better understand the role of mechanical loading on VSMCs in vascular disease development, it is imperative to understand the mechanical properties of VSMCs themselves. To measure the viscoelastic and frictional properties of living VSMCs in an in vitro setting, an atomic force microscope (AFM) was utilized, thereby allowing for mechanical testing of living cells in a fluid environment. In the first phase of research, …

Go to article

Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui Dec 2008

Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui

All Dissertations

The current tissue engineering paradigm is that successfully engineered thick tissues must include vasculature. As biological approaches alone such as VGEF have fallen short of their promises, one may look for an engineering approach to build microvasculature. With the advent of cell printing, one may be able to build precise human microvasculature with suitable bio-ink. Human Microvascular Endothelial Cells (HMVEC) and fibrin were studied as bio-ink for microvasculature construction. Endothelial cells are the only cells to compose the human capillaries and also the major cells of blood vessel intima layer. Fibrin has been already widely recognized as tissue engineering scaffold …

Go to article

Effect Of Clinically Relevant Mechanical Forces On Smooth Muscle Cell Response In Model Of Balloon Angioplasty, Kara Acampora Dec 2008

Effect Of Clinically Relevant Mechanical Forces On Smooth Muscle Cell Response In Model Of Balloon Angioplasty, Kara Acampora

All Dissertations

Restenosis remains a common problem affecting the patency of endovascular intervention such as balloon angioplasty and stent placement as treatments for atherosclerosis. Denudation of the endothelial layer and the increased injury from balloon deployment can cause phenotypic changes in surrounding vascular smooth muscle cells (SMCs) in vivo. The presented work modeled this mechanical environment in vitro to investigate the role of the altered mechanical environment on the phenotypic response of SMCs. Through the system design and CFD channel characterization, a six-independent-channel system providing low oscillating wall shear stress (WSS) was manufactured to apply concurrent shear and tensile forces with uniform …

Go to article

Wild Pig Habitat Use, Substrate Disturbance, And Understory Vegetation At Congaree National Park, Scott Zengel Dec 2008

Wild Pig Habitat Use, Substrate Disturbance, And Understory Vegetation At Congaree National Park, Scott Zengel

All Dissertations

Substrate disturbance by wild pigs ( Sus scrofa L.), mainly wild pig rooting, was evaluated bi&ndashmonthly over three years in fixed 1,000 m2 plots at Congaree National Park, South Carolina, USA. The study compared hog substrate disturbance among four habitats: three mature wetland floodplain forest types (mixed bottomland hardwoods, cypress&ndashtupelo swamp, seepage floodplain forest), and successional upland pine flatwoods adjacent to the floodplain (including former pine plantation). New disturbance included fresh signs of hog substrate disturbance. Total disturbance included both new and older hog disturbance still visible on the landscape (equivalent to all disturbance that would be recorded under less …

Go to article

Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash Dec 2008

Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash

All Dissertations

Piezoelectrically-driven (piezoactive) systems such as nanopositioning platforms, scanning probe microscopes, and nanomechanical cantilever probes are advantageous devices enabling molecular-level imaging, manipulation, and characterization in disciplines ranging from materials science to physics and biology. Such emerging applications require precise modeling, control and manipulation of objects, components and subsystems ranging in sizes from few nanometers to micrometers. This dissertation presents a comprehensive modeling and control framework for piezoactive micro and nano systems utilized in various applications.
The development of a precise memory-based hysteresis model for feedforward tracking as well as a Lyapunov-based robust-adaptive controller for feedback tracking control of nanopositioning stages are …

Go to article

Optimization Of Biodiesel Production From Crude Cottonseed Oil And Waste Vegetable Oil:Conventional And Ultrasonic Irradiation Methods, Xiaohu Fan Dec 2008

Optimization Of Biodiesel Production From Crude Cottonseed Oil And Waste Vegetable Oil:Conventional And Ultrasonic Irradiation Methods, Xiaohu Fan

All Dissertations

Biodiesel, derived from the transesterification of vegetable oils or animal fats with simple alcohols, has attracted more and more attention recently. As a cleaner burning diesel alternative, biodiesel has many attractive features including: biodegradability, nontoxicity, renewability and low emission profiles.
Although cottonseed oil was the first commercial cooking oil in the U.S, it has progressively lost its market share to some vegetable oils that have larger production and less cost. However, regarding the active researches on biodiesel production from vegetable oils, there is a promising prospective for the cottonseed oil as a feedstock for biodiesel production, which may enhance the …

Go to article

Novel Xanthine And Oxanine Dna Glycosylase Activities In Yeast And Mammalian Systems, Liang Dong Dec 2008

Novel Xanthine And Oxanine Dna Glycosylase Activities In Yeast And Mammalian Systems, Liang Dong

All Dissertations

DNA that stores genetic information is frequently damaged in cells. The DNA bases carrying an exocyclic amino group [adenine (A), guanine (G), cytosine (C)] encounter deamination even under physiological conditions. Xanthine (X) and the newly discovered oxanine (O) are derived from deamination of guanine; they are potentially cytotoxic and mutagenic lesions. However, in yeast and eukaryotes, studies on the enzymatic repair of these lesions are limited.
In the yeast, Schizosaccharomyces pombe thymine-DNA glycosylase (Spo TDG) is homologous to human thymine-DNA glycosylase (hTDG), an enzyme that removes thymine from T/G pair. It was reported that Spo TDG contains uracil DNA glycosylase …

Go to article

Agritourism As A Viable Strategy For Economic Diversification: A Case Study Analysis Of Policy Options For The Bahamas, Erecia Hepburn Dec 2008

Agritourism As A Viable Strategy For Economic Diversification: A Case Study Analysis Of Policy Options For The Bahamas, Erecia Hepburn

All Dissertations

This research examines the prospects for developing an economic diversification policy for The Bahamas, utilizing agritourism. The Bahamas is plagued with the dominance of one traditional sector, tourism combined with the lack of economic innovation and the inability to maintain domestic demand for food security, which has the potential for economic crisis if there are any serious 'external shocks' or setbacks in mainstream tourism. Such a possible drop in tourism is most evident from experiences in 2001 with the Straw Market fire of Sept 4th, and the terrorist attacks in America on September 11th, coupled with the escalating cost of …

Go to article

Dna Deamination Repair Enzymes In Bacterial And Human Systems, Rongjuan Mi Dec 2008

Dna Deamination Repair Enzymes In Bacterial And Human Systems, Rongjuan Mi

All Dissertations

DNA repair enzymes and pathways are diverse and critical for living cells to maintain correct genetic information. Single-strand-selective monofunctional uracil DNA glycosylase (SMUG1) belongs to Family 3 of the uracil DNA glycosylase superfamily. We report that a bacterial SMUG1 ortholog in Geobacter metallireducens (Gme) and the human SMUG1 enzyme are not only uracil DNA glycosylases (UDG), but also xanthine DNA glycosylases (XDG). Mutations at M57 (M57L) and H210 (H210G, H210M, H210N) can cause substantial reductions in XDG and UDG activities. Increased selectivity is achieved in the A214R mutant of Gme SMUG1 and G60Y completely abolishes XDG and UDG activity. Most …

Go to article

Vascular Tissue Engineering: The Creation Of Living, Non-Thrombogenic, Functional Blood Vessels Based On Elastin Scaffolds, Aditee Kurane Dec 2008

Vascular Tissue Engineering: The Creation Of Living, Non-Thrombogenic, Functional Blood Vessels Based On Elastin Scaffolds, Aditee Kurane

All Dissertations

Cardiovascular diseases are the leading cause of death worldwide. Blood vessel replacement is a common treatment for vascular diseases such as atherosclerosis, restenosis and aneurysm, with over 300,000 bypass procedures performed each year. However, vein grafts are limited due to their availability. Although synthetic vascular replacements have been successful for large diameter arteries, they have shown minimal success in arteries with diameters <6mm. This is because most synthetic materials induce thrombus formation which, within a few months of implantation, causes failure of the vascular graft due to occlusion. Tissue engineering is a promising approach to the fabrication of non-thrombogenic vascular grafts, but a reliable and expandable cell source for tissue-engineered vascular graft (TEVG) has not been established.
The work presented here is motivated by the current unavailability of an ideal tissue engineered blood vessel replacement. Our overall goal is to create a living tissue engineered vascular graft that is biodegradable, non-thromobogenic, presents low antigenicity and …

Go to article

Experimental And Modeling Studies For Optimizing Flocculant-Aided Sediment Retention Ponds, Byung Joon Lee Dec 2008

Experimental And Modeling Studies For Optimizing Flocculant-Aided Sediment Retention Ponds, Byung Joon Lee

All Dissertations

Attempts to control sediment-containing runoff and associated water quality problems have involved the establishment of many small to medium sediment retention ponds and the injection of nonionic and anionic polyacrylamide (PAM) flocculants to enhance colloid removal. However, to date use has been driven more by practicing engineers and trial-and-error approaches than by logical and consistent design approaches. Therefore, the purpose of this research was to optimize colloidal clay removal in PAM-aided sediment retention ponds by applying experimental and theoretical methodologies.
Initially, simple measurement techniques for the molecular weight (MW) and charge density (CD) of various PAMs were tested and their …

Go to article

Functional Characterization Of Hexokinase-Like 1 (Hkl1) From Arabidopsis Thaliana, Abhijit Karve Dec 2008

Functional Characterization Of Hexokinase-Like 1 (Hkl1) From Arabidopsis Thaliana, Abhijit Karve

All Dissertations

Arabidopsis hexokinase1 (AtHXK1) is a moonlighting protein with roles in both glucose signaling and catalysis. In this study, we first cloned and characterized the six HXK related genes from Arabidopsis. Three of the six encoded proteins were shown not to phosphorylate hexoses and thus, are designated as hexokinase-like (HKL) proteins. Though they are only 50% identical to HXK1, the amino acid sequences of HKL1 and HKL2 both have well conserved glucose binding domains and other recognized structural elements. The possible basis for their lack of catalytic activity was further probed by site-directed mutagenesis and ultimately was attributed to a suite …

Go to article

The Tiger Vol. 102 Issue 23 2008-11-14, Clemson University Nov 2008

The Tiger Vol. 102 Issue 23 2008-11-14, Clemson University

Tiger Newspapers

No abstract provided.

Go to article

The Tiger Vol. 102 Issue 22 2008-11-07, Clemson University Nov 2008

The Tiger Vol. 102 Issue 22 2008-11-07, Clemson University

Tiger Newspapers

No abstract provided.

Go to article

Human Health & Water Issues - Micro & Macro: Harmful Algal Blooms, Climate Change & Infectious Diseases Disaster-Related H20 Injuries, Illnesses, Robert Ball Oct 2008

Human Health & Water Issues - Micro & Macro: Harmful Algal Blooms, Climate Change & Infectious Diseases Disaster-Related H20 Injuries, Illnesses, Robert Ball

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Regional Assessments Of Nutrient Sources, Transport, And Delivery To Streams And Coastal Areas, Mike Woodside Oct 2008

Regional Assessments Of Nutrient Sources, Transport, And Delivery To Streams And Coastal Areas, Mike Woodside

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Managing Water Supply In Turbulent Times, David T. Zimmer Oct 2008

Managing Water Supply In Turbulent Times, David T. Zimmer

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

A Flexible Indicator-Based Approach To Assessing The Ecological Integrity Of South Carolina Watersheds, John A. Kupfer, Peng Gao Oct 2008

A Flexible Indicator-Based Approach To Assessing The Ecological Integrity Of South Carolina Watersheds, John A. Kupfer, Peng Gao

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

A Probabilistic Stream Assessment To Support Freshwater Conservation: Preliminary Results From The Coastal Plain, Mark C. Scott Oct 2008

A Probabilistic Stream Assessment To Support Freshwater Conservation: Preliminary Results From The Coastal Plain, Mark C. Scott

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Think Globally, Act Locally: Changing The World From Our Own Backyard - The Waccamaw Riverkeeper Program Of Winyah Rivers Foundation, Christine Ellis Oct 2008

Think Globally, Act Locally: Changing The World From Our Own Backyard - The Waccamaw Riverkeeper Program Of Winyah Rivers Foundation, Christine Ellis

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Effects Of Episodic Copper Exposures On Population Fitness, Holly M. Zahner, Stephen J. Klaine Oct 2008

Effects Of Episodic Copper Exposures On Population Fitness, Holly M. Zahner, Stephen J. Klaine

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

The Effects Of Duration And Concentration Of Episodic Zinc Exposure To The Fathead Minnow, P. Promelas, J H. Bisesi, S J. Klaine Oct 2008

The Effects Of Duration And Concentration Of Episodic Zinc Exposure To The Fathead Minnow, P. Promelas, J H. Bisesi, S J. Klaine

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

The Development Of User-Friendly Publications To Advance Locally Led Watershed-Scale Assessment, Protection And Restoration In South Carolina, Robin W. Kloot, Amy Maxwell, Kellee Melton, Tibor Horvarth, Dick Yetter Oct 2008

The Development Of User-Friendly Publications To Advance Locally Led Watershed-Scale Assessment, Protection And Restoration In South Carolina, Robin W. Kloot, Amy Maxwell, Kellee Melton, Tibor Horvarth, Dick Yetter

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Fecal Coliform Tmdl Implementation Success Stories In Two Watersheds, Christine L. Boring, William R. Thomson Oct 2008

Fecal Coliform Tmdl Implementation Success Stories In Two Watersheds, Christine L. Boring, William R. Thomson

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Fecal Coliform Bacteria Tmdl Implementation On Cane Creek And Little Cane Creek In Oconee County, South Carolina, George M. Huddleston Iii, Morris B. Warner, Louwantda W. Jolley, Nicole L. Fahrenfeld, Alan W. Elzerman, Marirosa Molina, Yong J. Lee, Robert R. Swank Jr Oct 2008

Fecal Coliform Bacteria Tmdl Implementation On Cane Creek And Little Cane Creek In Oconee County, South Carolina, George M. Huddleston Iii, Morris B. Warner, Louwantda W. Jolley, Nicole L. Fahrenfeld, Alan W. Elzerman, Marirosa Molina, Yong J. Lee, Robert R. Swank Jr

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Enabling Broadband Data Access For The Digital Watershed With Heterogenous Wireless Networks, Gayatri Venkatesh, Kuang-Ching Wang, Christopher Post Oct 2008

Enabling Broadband Data Access For The Digital Watershed With Heterogenous Wireless Networks, Gayatri Venkatesh, Kuang-Ching Wang, Christopher Post

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

Managing Coastal Urbanization And Development In The 21st Century: Balancing Human Dimensions And Water Quality Issues, Geoff Scott Oct 2008

Managing Coastal Urbanization And Development In The 21st Century: Balancing Human Dimensions And Water Quality Issues, Geoff Scott

S.C. Water Resources Conference

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Region

Go to article

First Prev Next Last