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Full-Text Articles in Biomedical Engineering and Bioengineering

Guiding Electric Fields For Electroporation Applications, Jose Rey Jan 2011

Guiding Electric Fields For Electroporation Applications, Jose Rey

Graduate Theses and Dissertations

Electroporation is the critical step in an electric field mediated drug or gene delivery protocol. Electroporation based protocols have been successfully demonstrated in cancer clinical trials, however, its impact in other applications is still under investigation. A significant roadblock to long term functioning of implantable biosensors in vivo is the tissue reaction in the form of fibrous encapsulation that results in reduced transport to the sensing element of the biosensor. In vivo gene electroporation has a great potential as a means to modify the transport properties of tissues in the proximity of the sensing element of implantable biosensors.

This dissertation ...


Surface Functionalization And Analysis Thereof For An Ovarian Cancer Diagnostic Biosensor, Asad Ali Ahmad Jan 2011

Surface Functionalization And Analysis Thereof For An Ovarian Cancer Diagnostic Biosensor, Asad Ali Ahmad

Graduate Theses and Dissertations

Ovarian cancer is the fifth leading cause of cancer death among women in United States and has an alarming 1.4% (1 in 71) lifetime risk. The lack of overt symptoms and the absence of a reliable screening test to detect ovarian cancer result in over 70% of women being diagnosed after the disease has spread beyond the ovary resulting in a poor prognosis. A key characteristic of ovarian cancer is the ability of tumor cells to evade apoptosis, or programmed cell death contributing to the limitless replicative potential, which is a hallmark of all carcinogenesis. There is conclusive evidence ...


A Novel Device For Cell-Cell Electrofusion, Justin T. Stewart Jan 2011

A Novel Device For Cell-Cell Electrofusion, Justin T. Stewart

Graduate Theses and Dissertations

Cell transplantation therapy is a potentially powerful tool and can be used to replace defective cells with healthy cells. This offers the possibility of alleviating the destructive symptoms for many diseases such as Parkinson's disease, Alzheimer's disease, stroke, spinal cord trauma, Type I diabetes and many more. While there are many diseases that could be positively impacted from cell transplantation therapy, the focus of this research is insulin dependent, Type I Diabetes.

The Islets of Langerhans are composed of various types of cells located in the pancreas and are responsible for a variety of biochemical functions. Specifically, the ...


Use Of Colloidal Crystal Templating To Fabricate Ordered Pit Arrays On Aluminum And Aluminum Alloy 3003, Newira Widharta Jan 2011

Use Of Colloidal Crystal Templating To Fabricate Ordered Pit Arrays On Aluminum And Aluminum Alloy 3003, Newira Widharta

Graduate Theses and Dissertations

In a number of industrial processes, metal surfaces are etched to develop topographic patterns consisting of microscopic cavities. Al alloy plates for lithographic printing are etched to create a microscopically roughened surface that optimizes retention of ink and release agent. Fabrication of ordered arrays of micro-porous pits utilizing colloidal crystal templating method in aluminum and aluminum alloy 3003 was developed in this thesis. We choose such a technique, previously developed for aluminum electrolytic capacitors, and adapt it to aluminum alloy 3003 substrates used in the solid-ink lithography. Using electrochemistry and imaging techniques (SEM), we showed that ordered pit arrays with ...


Multiple Disturbance Modeling And Prediction Of Blood Glucose In Type 1 Diabetes Mellitus, Kaylee Renee Kotz Jan 2011

Multiple Disturbance Modeling And Prediction Of Blood Glucose In Type 1 Diabetes Mellitus, Kaylee Renee Kotz

Graduate Theses and Dissertations

Type 1 diabetics often experience extreme variations in glucose concentrations which can have adverse long– and short–term effects such as severe hypoglycemia, hyperglycemia and organ degeneration. Studies have established that there is a need to maintain the glucose levels within a normal range (e.g. 80—150 mg/dL) to avoid complications caused by diabetes. However, initial attempts to regulate blood glucose levels using insulin infusion pumps, multiple injections or a combination of the two have had limited success as they lack the ability to decide the appropriate rate and/or dose of insulin based on the current metabolic ...


Steam Reforming Of Water-Soluble Fast Pyrolysis Bio-Oil: Studies On Bio-Oil Composition Effect, Carbon Deposition, And Catalyst Modifications, Pedro J. Ortiz-Toral Jan 2011

Steam Reforming Of Water-Soluble Fast Pyrolysis Bio-Oil: Studies On Bio-Oil Composition Effect, Carbon Deposition, And Catalyst Modifications, Pedro J. Ortiz-Toral

Graduate Theses and Dissertations

Bio-oils from fast pyrolysis of lignocellulosic biomass can be phase separated into a heavy water insoluble portion and a light water-soluble portion. The water-rich portion contains mainly carboxylic acids, carbohydrates, aldehydes, ketones and alcohols. This highly oxygenated water-rich portion was evaluated for production of the renewable hydrogen required for the upgrading reactions. There are certain challenges introduced due to the complexity of these mixtures. Catalyst deactivation by coking and the formation of carbon deposits are major limitations although the specific causes were previously unidentified. A bio-oil fractionating system can separate heavier components from the light-end components. This light-end fraction has ...


Combinatorial Design And Development Of Biomaterials For Use As Drug Delivery Devices And Immune Adjuvants, Latrisha Kay Petersen Jan 2011

Combinatorial Design And Development Of Biomaterials For Use As Drug Delivery Devices And Immune Adjuvants, Latrisha Kay Petersen

Graduate Theses and Dissertations

There are several challenges associated with current strategies for drug and vaccine delivery. These include the need for multiple-dose administrations, which can hinder patience compliance, the requirements for specific storage conditions due to the fragile structure of protein-based molecules, and the need for additional excipients to enhance protein stability or adjuvant the immune response. This work has focused on the development of a high throughput, combinatorial approach to optimize degradable polymeric biomaterials, specifically polyanhydrides, to overcome these challenges associated with drug and vaccine delivery. We have developed high throughput techniques to rapidly fabricate polymer film and nanoparticle libraries to carry ...


Surface Functionalization Of Quantum Dots For Biotechnological Applications, Yanjie Zhang Jan 2011

Surface Functionalization Of Quantum Dots For Biotechnological Applications, Yanjie Zhang

Graduate Theses and Dissertations

Quantum dots (QDs) are considered as fantastic substitutes for organic dyes or genetically coded proteins because of their outstanding optical properties including broad absorption spectra, size tunable emission spectra, large extinction coefficient and superior resistance to chemical and physical degradation. They are now widely used in many biological applications. However, QDs are generally synthesized using organometallic approach and only soluble in organic solvents. To transfer QDs into aqueous solution, we replaced their native ligands with a new group of water-soluble molecules based on simple yet flexible dithiocarbamate chemistry. This cap exchange method offers QDs not only solubility but also stability ...


Purification Of Flavan-3-Ol Biosynthesis For Co-Localization Onto Nanocarriers And A Multi-Enzyme Assay, Emily Kaitlin Davenport Jan 2011

Purification Of Flavan-3-Ol Biosynthesis For Co-Localization Onto Nanocarriers And A Multi-Enzyme Assay, Emily Kaitlin Davenport

Graduate Theses and Dissertations

Flavonoids are polyphenolic secondary metabolites that serve a variety of purposes, from assisting pollination in plants to providing anti-cancerous activity in humans. It is the wide range of functions that give these molecules the highly revered status they have today. Range in function can be linked with the range in structure, and with over 10,000 different flavonoids known, they make up one of the largest groups of natural products. One common sub-class of flavonoids is the flavan-3-ols, which are known for their health benefits and tendency to condense to form proanthocyanidins, or condensed tannins. Both of these classes of ...


Engineering Amphiphillic Polyanhydride Particle Platform For Targeted Drug And Vaccine Delivery, Brenda Rocio Carrillo-Conde Jan 2011

Engineering Amphiphillic Polyanhydride Particle Platform For Targeted Drug And Vaccine Delivery, Brenda Rocio Carrillo-Conde

Graduate Theses and Dissertations

In this work, a transdisciplinary approach that combines concepts from biomaterials, nanotechnology, carbohydrate and protein chemistry, molecular biology, immunology and computational analysis has been applied to rationally design and engineer novel vaccine platforms that encompass passive and active targeting strategies.

First, the intrinsic properties of the polyanhydride systems utilized in these studies were tailored to achieve the stability of proteins with the potential to be used as antigens and/or therapeutic agents. Amphiphillic polyanhydride chemistries showed the most optimal properties to preserve structural integrity and functionality of different proteins. The surface chemistry of polyanhydride particles was also identified as an ...


Functional Materials From Hierarchically Ordered Polymer Nanocomposites, Brandon Josef Franck Jan 2011

Functional Materials From Hierarchically Ordered Polymer Nanocomposites, Brandon Josef Franck

Graduate Theses and Dissertations

We report work done studying the segregation of polymer coated gold nanoparticles within block copolymer (BCP) composites. Poly(styrene-b-isoprene) (PI-b-PS) of Mn 172 kDa was loaded with various particle fractions of gold nanoparticle with various surface chemistries. Segregation of the particles within the BCP composite was examined via electron microscopy. "Single component" nanocomposites with BCP ligands of PI-b-PS and poly(isoprene-b-dimethylsiloxane) "grafted to" gold nanoparticles were introduced and a study of ordering was done via electron microscopy and small-angle x-ray scattering.


Biological Effective Dose (Bed) Distribution Matching For Obtaining Brachytherapy Prescription Doses & Dosimetric Optimization For Hybrid Seed Brachytherapy, Jakub Pritz Jan 2011

Biological Effective Dose (Bed) Distribution Matching For Obtaining Brachytherapy Prescription Doses & Dosimetric Optimization For Hybrid Seed Brachytherapy, Jakub Pritz

Graduate Theses and Dissertations

Radioactive seed implant brachytherapy is a common radiotherapy treatment method for prostate cancer. In current clinical practice, a seed consists of a single isotope, such as 125I or 103Pd. A seed containing a mixture of two isotopes has been proposed for prostate cancer treatment. This study investigates a method for defining a prescription dose for new seed compositions based on matching the biological equivalent dose (BED) of a reference plan.

Ten prostate cancer cases previously treated using single isotope seeds (5 using 125I seeds and 5 using 103Pd seeds) were selected for this study. Verification of the method was done ...


Feasibility Of Wearable Sensors To Determine Gait Parameters, Mario Alves Simoes Jan 2011

Feasibility Of Wearable Sensors To Determine Gait Parameters, Mario Alves Simoes

Graduate Theses and Dissertations

A wearable system that can be used in different settings to collect gait parameters on subjects with a mild traumatic brain injury (mTBI) would allow clinicians to collect needed data of subjects outside of the laboratory setting. Mild traumatic brain injuries stem from a number of causes such as illnesses, strokes, accidents or battlefield traumas. These injuries can cause issues with everyday tasks, such as gait, and are linked with vestibular dysfunction [1]. Different wearable sensor systems were analyzed prior to starting this study along with relevant gait parameters associated with mild traumatic brain injury. To monitor gait parameters relevant ...


Two-Dimensional Computer Model Of Human Atrial Ablation, Samineh R. Esfahani Jan 2011

Two-Dimensional Computer Model Of Human Atrial Ablation, Samineh R. Esfahani

Graduate Theses and Dissertations

A finite-element model of a two-dimensional slice of human atrial tissue for the study of the electrograms and propagation of action potentials is presented. Action potential propagation is described by a reaction-diffusion model coupled with the complex Courtemanche et al. atrial cell model. The effects of recording electrode size and location on electrograms are presented. Action potential propagation as a result of atrial fibrillation ablation therapy is also modeled by defining a lesion area with decreased electrical conductivity. The effect of electrical conductivity and geometry of the lesion was also studied. It is shown that the success rate of atrial ...


Heterogeneous Modeling Of Medical Image Data Using B-Spline Functions, Olya Grove Jan 2011

Heterogeneous Modeling Of Medical Image Data Using B-Spline Functions, Olya Grove

Graduate Theses and Dissertations

Ongoing developments in the field of medical imaging modalities have pushed the frontiers of modern medicine and biomedical engineering, prompting the need for new applications to improve diagnosis, treatment and prevention of diseases.

Biomedical data visualization and modeling rely predominately on manual processing and utilization of voxel and facet based homogeneous models. Biological structures are naturally heterogeneous and in order to accurately design and biomimic biological structures, properties such as chemical composition, size and shape of biological constituents need to be incorporated in the computational biological models.

Our proposed approach involves generating a density point cloud based on the intensity ...


Atrial Fibrillation Signal Analysis, Raja Sarath Chandra Prasad Vaizurs Jan 2011

Atrial Fibrillation Signal Analysis, Raja Sarath Chandra Prasad Vaizurs

Graduate Theses and Dissertations

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia encountered in clinical practice and is associated with an increased mortality and morbidity. Identification of the sources of AF has been a goal of researchers for over 20 years. Current treatment procedures such as Cardio version, Radio Frequency Ablation, and multiple drugs have reduced the incidence of AF. Nevertheless, the success rate of these treatments is only 35-40% of the AF patients as they have limited effect in maintaining the patient in normal sinus rhythm. The problem stems from the fact that there are no methods developed to analyze ...


Multiscale Modeling For Complex Macromolecular Systems: Methodologies And Applications, Seung Ha Kim Jan 2011

Multiscale Modeling For Complex Macromolecular Systems: Methodologies And Applications, Seung Ha Kim

Graduate Theses and Dissertations

The objective of this dissertation is to understand the binding mechanism between flexible macromolecules and guest species in solution using multiscale molecular modeling strategies, including: ab initio electronic structure theory, all-atom classical molecular dynamics simulations, coarse-grained molecular dynamics simulations, and statistical eld theory. A brief summary of the subsequent chapters in this thesis is provided. Chapters 2 - 7 and Appendix A are self-contained units complete with literature review and bibliography.


High Throughput Design Of Functionalized Nanoparticles For Targeted Vaccine Delivery, Ana Vianey Chavez-Santoscoy Jan 2011

High Throughput Design Of Functionalized Nanoparticles For Targeted Vaccine Delivery, Ana Vianey Chavez-Santoscoy

Graduate Theses and Dissertations

This dissertation focuses on the design of functionalized nanoparticles, a novel approach to targeted antigen delivery by decorating the surface of polyanhydride nanoparticles with specific carbohydrates to provide "pathogen-like" properties.

Polyanhydride nanoparticles are promising vaccine platforms that have the potential to be used as controlled drug delivery devices as well as potent and effective immune adjuvants for the design of single dose vaccines. CLRs offer unique advantages for tailoring immune responses. Engagement of CLRs regulates antigen presenting cell activation and promotes delivery of antigens to specific intracellular compartments inside antigen presenting cells for efficient processing and presentation.

CLRs recognize conserved ...


Modeling Of Complex Surface Interactions In Low And High Pressure Plasmas, Mingmei Wang Jan 2011

Modeling Of Complex Surface Interactions In Low And High Pressure Plasmas, Mingmei Wang

Graduate Theses and Dissertations

Plasma etching (or dry etching) is widely used in the fabrication of integrated cir-cuits (IC). Anisotropic features are easily obtained by controlling reactive ion trajectories in plasma. Twisting and bowing are two main issues during high aspect ratio (HAR) fea-ture etching. Twisting is, instead of a feature etching vertically, the feature twists or turns to the side. Mixing damage by ion bombardment of underlying materials is also a critical problem in post-etch processing. One of the explanations for twisting is charge accumu-lation on feature surfaces during ion bombardment. An asymmetric local electric field (E-field) changes ion trajectories incident into the ...


Metabolic Flux Analysis Of Escherichia Coli Mg1655 Under Octanoic Acid (C8) Stress, Yanfen Fu Jan 2011

Metabolic Flux Analysis Of Escherichia Coli Mg1655 Under Octanoic Acid (C8) Stress, Yanfen Fu

Graduate Theses and Dissertations

Metabolic engineering has evolved to the point of fulfilling the dream of having industrial chemicals produced renewably. Carboxylic acids [e.g., short chain fatty acids (SCFAs) such as octanoic acid (C8)] are such chemical intermediates that can be produced by Escherichia coli engineered with thioesterases specific for short chain fatty acids. However, C8 is toxic to E. coli at concentration greater than 10 mM. To design a better host strain for the production of large amount of SCFAs, 13C metabolic flux analysis of E. coli was performed for both C8 stress and control condition (without C8). To investigate central carbon ...


Self-Assembled Pentablock Copolymers For Selective And Sustained Gene Delivery, Bingqi Zhang Jan 2011

Self-Assembled Pentablock Copolymers For Selective And Sustained Gene Delivery, Bingqi Zhang

Graduate Theses and Dissertations

The poly(diethylaminoethyl methacrylate) (PDEAEM) - Pluronic F127 - PDEAEM pentablock copolymer (PB) gene delivery vector system has been found to possess an inherent selectivity in transfecting cancer cells over non-cancer cells in vitro, without attaching any targeting ligands. In order to understand the mechanism of this selective transfection, three possible intracellular barriers to transfection were investigated in both cancer and non-cancer cells. We concluded that escape from the endocytic pathway served as the primary intracellular barrier for PB-mediated transfection. Most likely, PB vectors were entrapped and rendered non-functional in acidic lysosomes of non-cancer cells, but survived in less acidic lysosomes of ...