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Articles 1 - 11 of 11

Full-Text Articles in Biomedical Engineering and Bioengineering

A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao Dec 2016

A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao

Theses and Dissertations

Foodborne diseases are a growing public health problem. In recent years, many rapid detection methods have been reported, but most of them are still in lab research and not practical for use in the field. In this study, a portable and automatic biosensing instrument was designed and constructed for separation and detection of target pathogens in food samples using nanobead-based magnetic separation and quantum dots (QDs)-labeled fluorescence measurement. The instrument consisted of a laptop with LabVIEW software, a data acquisition card (DAQ), a fluorescent detector, micro-pumps, stepper motors, and 3D printed tube holders. First, a sample in a syringe ...


Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker Dec 2016

Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker

Theses and Dissertations

Following injury to the central nervous system, extracellular modulations are apparent at

the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of ...


A Bifunctional Nanocomposites Based Electrochemical Biosensor For In-Field Detection Of Pathogenic Bacteria In Food, Meng Xu Dec 2016

A Bifunctional Nanocomposites Based Electrochemical Biosensor For In-Field Detection Of Pathogenic Bacteria In Food, Meng Xu

Theses and Dissertations

This research focused on the application of electrochemical biosensors for the rapid detection of pathogenic bacteria, Escherichia coli O157:H7 and Salmonella Typhimurium, in foods. The possible presence of pathogenic bacteria in foods has always been a great threat to the wellbeing of people and the revenue of food companies. Therefore, the demand for rapid and sensitive methods to detect foodborne pathogens is growing. In this research, an impedimetric immunosensor was first developed for the rapid detection of E. coli O157:H7 and S. Typhimurium in foods. It was based on the techniques of immunomagnetic separation, enzyme labelling, and electrochemical ...


Examination Of Pseudomonas Fluorescence As A Recombinant Expression Host: Cloning, Expression, And Chromatography, Ahmed K.Ali Elmasheiti Dec 2016

Examination Of Pseudomonas Fluorescence As A Recombinant Expression Host: Cloning, Expression, And Chromatography, Ahmed K.Ali Elmasheiti

Theses and Dissertations

In an effort to expand the pool of bacterium useful for biotechnology applications, Pseudomonas fluorescens, a common gram negative microbe, was examined for its ability to function in a recombinant setting. P. fluorescens is ubiquitous in nature and was initially identified as a soil bacterium found in dirt and is typically associated with plant material. Past literature indicates that it shared characteristics common to Escherichia coli and Bacillus subtilis, including simple growth conditions and potential cloning vectors, providing motivation to look into both the upstream and downstream characteristics of this bacterium. First, it was demonstrated that P. fluorescens could be ...


Storage Of Round And Square Switchgrass Bales: Effect Of Storage Time And Fungal Inoculation On Saccharification Efficiency, Noaa Frederick Dec 2015

Storage Of Round And Square Switchgrass Bales: Effect Of Storage Time And Fungal Inoculation On Saccharification Efficiency, Noaa Frederick

Theses and Dissertations

To produce fermentable sugars from lignocellulosic biomass feedstock, severe pretreatment conditions are needed (either high acid concentration, temperature, or retention times). High severities can produce toxic byproducts which inhibit enzymatic hydrolysis or fermentation. In order to reduce pretreatment severities (and thus increase enzyme and fermentation efficiency), the white-rot fungus Pleurotus ostreastus was seeded into square and round bales of Kanlow switchgrass (Panicum virgastum L.) and left in the field over a period of 9 month. The laccase producing fungus is believed to selectively degrade lignin, a common plant structural polymer, which can function as an enzymatic inhibitor. Samples were taken ...


Rupture In Abdominal Aortic Aneurysm, Qusay Alfaori Dec 2015

Rupture In Abdominal Aortic Aneurysm, Qusay Alfaori

Theses and Dissertations

Quantification of abdominal aortic aneurysm development, its growth kinetics, and rupture criteria are important to decrease the risk of this life-threatening event. Uniaxial testing of healthy and collagen degraded aortic specimens from pigs was performed. A mathematical model, from the literature, for the stress-strain relationship that is suitable for describing the behavior of abdominal aortic tissue was used to derive specific tissue properties/parameters as a function of strain rate and as a function of specimen orientation. Analyses consisting of Finite Element Modeling of healthy and collagen degraded abdominal aortas were performed using ABAQUS finite element code and the measured ...


Investigation Of The Inherent Chemical, Structural, And Mechanical Attributes Of Bio-Engineered Composites Found In Nature: Alligator Gar’S Exoskeleton Fish Scales, Wayne Derald Hodo Dec 2015

Investigation Of The Inherent Chemical, Structural, And Mechanical Attributes Of Bio-Engineered Composites Found In Nature: Alligator Gar’S Exoskeleton Fish Scales, Wayne Derald Hodo

Theses and Dissertations

The U.S. Army has determined a huge cost savings of up to 51% can be accomplished by reducing the gross vehicle weight, for their personnel carrier, by 33%. To cut cost, composite materials are needed. Man-made composites can have superior material properties (high-strength, high-fracture toughness, and lightweight), but they are prone to delamination at the glued-layered interface. In contrast, fish scale is a natural composite that has the same material properties and, additionally, tend not to delaminate.

The focus of this study was to learn how nature integrates hard and soft materials at each length scale to form a ...


Capillary Electrophoresis For Analysis Of Aβ1-42 Adsorption And Photo-Crosslinking, Jennifer Lynn Kurtz Jul 2015

Capillary Electrophoresis For Analysis Of Aβ1-42 Adsorption And Photo-Crosslinking, Jennifer Lynn Kurtz

Theses and Dissertations

The accumulation of amyloid-beta (Aβ) oligomers is believed to be the driving force behind Alzheimer’s disease (AD) pathogenesis. Due to the metastable nature of Aβ oligomers, the knowledge of Aβ aggregation and accumulation is not well understood. Here, we use capillary electrophoresis (CE) and photo-induced crosslinking of unmodified proteins (PICUP) to learn about the aggregation of Aβ.

First, we explore the effect of capillary coating on Aβ1-42 protein loss using CE. The dynamic coatings tested were PHEA and 50 kDa, 2000 kDa, 5000 kDa, and 8000 kDa PEO. The covalent coating tested was PVA. The results indicated that 2000 ...


Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai Aug 2013

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

Theses and Dissertations

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made ...


Aptamer-Based Spr Biosensor For Detection Of Avian Influenza Virus, Hua Bai May 2012

Aptamer-Based Spr Biosensor For Detection Of Avian Influenza Virus, Hua Bai

Theses and Dissertations

Rapid and specific detection of avian influenza (AI) virus is urgently needed with the concerns over the outbreaks of highly pathogenic H5N1 avian influenza in animal and human infection. Aptamers are artificial oligonucleic acid that can specifically bind to target molecules. They show comparable affinity for target virus and better thermal stability than monoclonal antibodies. Those advantages make aptamers promising candidates in diagnostic and detection applications. The goal of this research was to use DNA&ndashaptamer as the specific recognition element in a portable surface plasmon resonance (SPR) biosensor for detection of AI H5N1 virus in poultry.

A SPR biosensor ...


Electrospun Polycaprolactone Nanofiber Scaffolds For Tissue Engineering, Andreas Haukas May 2012

Electrospun Polycaprolactone Nanofiber Scaffolds For Tissue Engineering, Andreas Haukas

Theses and Dissertations

Stem cell and tissue engineering offer us with a unique opportunity to research and develop new therapies for treating various diseases that are otherwise incurable using traditional medicines. However, development of these new therapies replies upon the establishment of in vitro cell culture and differentiation systems that mimic in vivo microenvironments required for cell-cell and cell-ECM interaction. The development of these cell culture systems depends upon the identification of appropriate biomaterials and cell sources. Biomaterials should be carefully selected and fabricated into scaffolds for supporting cell growth and differentiation. In this study, we explored the fabrication of 3D electrospun nanofiber ...