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Incorporation Of Capillary-Channeled Polymer (C-Cp) Fibers Into Micropipette Tips For Solid Phase Extraction With Applications In Bioanalysis, Donald Fornea

All Theses

Solid phase extraction (SPE), is a widely used sample preparation method that is currently experiencing a surge in research interest, clever architecture/format development, and stationary phase characterization.1-3 SPE devices commonly exist in syringe, cartridge, disk, and micropipette tip formats.4 Micropipette tip SPE has enhanced the determination of proteins by electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry (MS) by handling micro-liter volumes of sample and buffer removal/solvent exchange.5-7 Buffers have deleterious effects on ionization taking place in MS sources due to preferential ionization, ion suppression effects, and the formation of adduct species competing for ionization in …

Perfluoroalkyl (Aryl) Sulfonimide Zwitterions, Hua Mei

All Dissertations

This research focuses on superacid perfluoroalkyl(aryl) sulfonimides and their derivatives as a source of stable zwitterionic salts. The strong resonance stabilization of sulfonimides imparts unexpected stability to the zwitterions.
Two types of zwitterions were investigated. The first are symmetrical diaryliodonium zwitterions (DZs) as potential photo acid generators (PAGs) for microlithography. Driven by the demand for smaller feature sizes in the microelectronics industry, microlithography using shorter wavelength light has evolved and new PAGs are of interest. New DZs are potentially useful because they have good thermal stability and may be structurally modified to alter their spectral absorption characteristics. As an extension …

Characterization Of Capillary-Channeled Polymer Fibers As Stationary Phases For High-Performance Liquid Chromatography Of Macromolecules, Dwella Nelson

All Dissertations

Capillary-channeled polymer (C-CP) fibers are being developed and characterized as high-performance liquid chromatography (HPLC) stationary phases for reversed-phase separations of proteins. Conventional porous phases are not well suited for separating large macromolecules due to the slow diffusivity of the molecules, large diffusional distances, and stagnant mobile phase zones within the column. Stationary phases are continually being developed to address the challenges associated with HPLC of proteins and other macromolecules in general. C-CP fiber stationary phases are an alternative to conventional bead technology and offer a variety of chemical and physical advantages. The fibers can be selected for their chemical functionality …

Path Integral Formulation Of Langeinv Dynamics With Applications To Rare-Event Systems, Bradley Dickson

All Dissertations

In the last decade great efforts have been made to efficiently study the behaviors of rare-event systems. The methods and theories developed in pursuit of this goal are far from unified and are instead applied on a case-by-case basis where one makes a best educated guess as to which approach may afford the greatest chance of studying the rare-event system in question. The work contained here is directed at further development of one of these sets of methods and theories. Specifically, a new theory of dynamics in the Langevin path space is developed with emphasis on generating and sampling Langevin …

Synthesis Of Boronic Acid Based Sensors For Glucose And Sialic Acid And Synthesis Of Novel And Selective Pde4 Enzyme Inhibitors, Gurpreet Kaur

Chemistry Dissertations

The boronic acid functional group is known to bind compounds with the diol group tightly and reversibly in aqueous environment and has been used as a recognition moiety for the design of carbohydrate sensors. The first chapter of the dissertation studies the synthesis and substitution effect on the affinity and selectivity of a known boronic acid-based glucose sensor. In such a sensor design effort, the availability of a signaling event, whether it is fluorescence or UV, is crucial. The second chapter studies the detailed mechanism on how a well-known fluorescent boronic acid compound changes fluorescent properties upon binding. A new …

Insights Into Sulfonated Phthalocyanines; Insights Into Anionic Tetraaryl Porphyrins; Irradiation Of Cationic Metalloporphyrins Bound To Dna, Anila Fiaz Gill

Chemistry Dissertations

Sulfonated porphyrins and phthalocyanines have been under consideration as microbicides, compounds which, when used in a topical formulation, can prevent transmission of the human immunodeficiency virus. Our studies have been directed toward the characterization of members of these classes. For the sulfonated phthalocyanines, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was helpful in determining the extent of sulfonation. We present the first report of spectroscopic characterization of a pentasulfonated phthalocyanine. Capillary electrophoresis data were sensitive to the concentration of the compounds (Chapter 1). Mass spectrometry was also very useful for establishing the extent of sulfonation in series of sulfonated porphyrins. Capillary …

Syntheses And Dna Interactions Of Acridine And Phenothiazine Based Photosensitizers, Beth Wilson

Chemistry Dissertations

Photosensitizing molecules and/or metal complexes that interact with DNA via intercalation and groove binding have potential applications as molecular structural probes, as footprinting reagents and in photodynamic therapeutics. To this regard, small molecules that bind to DNA and the energetics involved in these interactions, acridine-based therapeutics, photosensitization, photodynamic therapy, phenothiazine-mediated photosensitization, DNA photocleavage reaction mechanisms and photosensitizing metal complexes are introduced in Chapter I. Next, in Chapter II, the synthesis of a photonuclease consisting of a 3,6-acridinediamine chromophore attached to four metal-coordinating imidazole rings is described. The DNA photocleavage yields, emission quantum yields, and thermal denaturation studies by this acridine-imadazole …

Selective Recognition Of Quadruplex Dna By Small Molecules, Elizabeth W. White

Chemistry Dissertations

Structure-specific recognition of nucleic acids is a promising method to reduce the size of the recognition unit required to achieve the necessary selectivity and binding affinity for small molecules. It has been demonstrated recently that G-quadruplex DNA structures can be targeted by organic cations in a structure-specific manner. Structural targets of quadruplexes include the planar end surfaces of the G-tetrad stacked columns as well as four grooves. The significant structural differences between quadruplex DNA and duplex DNA make quadruplex DNA a very attractive target for highly selective, structure-specific drug design. We have used a variety of biophysical techniques including circular …

Development Of Polymer Monoliths For The Analysis Of Peptides And Proteins, Binghe Gu

Theses and Dissertations

Several novel polymer monoliths for the analysis of peptides and proteins were synthesized using polyethylene glycol diacrylate (PEGDA) as crosslinker. Photo-initiated copolymerization of polyethylene glycol methyl ether acrylate and PEGDA yielded an inert monolith that could be used for size exclusion liquid chromatography of peptides and proteins. This macroscopically uniform monolith did not shrink or swell in either water or tetrahydrofuran. More importantly, it was found to resist adsorption of both acidic and basic proteins in aqueous buffer without any organic solvent additives. A strong cation-exchange polymer monolith was synthesized by copolymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and PEGDA. A ternary …

Synthesis And Optical Properties Of Four Oligothiophene-Ruthenium Complexes And Synthesis Of A Bidentate Ligand For C-F Bond Activation, Joseph S. Bair

Theses and Dissertations

Photovoltaic cells and fluorescence sensing are two important areas of research in chemistry. The combination of photon-activated electron donors with electron acceptors provides a strong platform for the study of optical devices. A series of four oligothiophene-ruthenium complexes has been synthesized. Variation in oligothiophene length and bipyridine substitution allowed comparison of these variables on electronic properties. The longer oligothiophenes display lower energy absorption and emission compared to the shorter ones. Aromatic conjugation appears more complete with para-, rather than meta-, substitution. Oligothiophenes and Ru(bpy)32+ are highly fluorescent individually, but fluorescence is quenched when connected. Bonds of carbon to fluorine are …

The Effect Of Mobile Phase Composition And Temperature On The Adsorption Behavior Of Tryptophan, Tarab Jamil Ahmad

Doctoral Dissertations

Single-component adsorption isotherm data were acquired by frontal analysis for tryptophan on a C₁₈-Kromasil packed column, using acetonitrile-water solutions of various compositions (2.5, 5, and 7.5% ACN + 1% ACOH). These isotherms have a complex behavior, exhibiting at least one clear inflection point at an intermediate concentration and, possibly, another such point, close to the origin. The isotherm for 2.5 % ACN has the strongest curvature. At high concentrations, all these isotherms tend toward a limit, showing that the adsorbent has a finite saturation capacity. At low concentrations, these isotherms seem to exhibit langmuirian behavior. The isotherm model …

Thermodynamic And Neutron Structural Studies Of Hydrocarbon Adsorption On Mgo Nanocubes, Richard E. Cook

Doctoral Dissertations

Presented is a series of thermodynamic and neutron scattering experiments used to probe the nature of the hydrocarbon - MgO (100) interaction. High-resolution volumetric isotherms are used to probe the wetting, layer transitions, heats of adsorption, two-dimensional compressibilities, and identify possible phase transitions of thin films of benzene, ethane, and n - pentane on MgO powders. Neutron diffraction experiments were used to probe the structure and identify any phase transitions within monolayer films of ethane, butane and n -pentane.

Benzene adsorption, while showing no visible layering steps, shows a shift in the shape of the isotherm for p/p_o > 0.7. …

Characterization Of Aβ Aggregates Using Hydrogen/Deuterium Exchange Mass Spectrometry, Maolian Chen

Doctoral Dissertations

The work presented in this dissertation aimed to localize the hydrogen-bonding interaction sites within Aβ aggregates associated with Alzheimer’s disease using hydrogen/deuterium exchange mass spectrometry (HDX-MS) coupled with proteolysis. Toward this end, an on-line digestion system utilizing a triaxial electrospray probe as the front end to MS was developed. Using this approach, regions of Aβ(1-40) fibrils and protofibrils that are protected from HDX have been identified. The HDX data show that the C-terminal segment 35-40 and the N-terminal segment 1-19 are highly exposed to exchange in both fibrils and protofibrils, while the internal fragment 20-34 is highly protected from exchange …

Direct Integration Of Surface Enhanced Raman Spectroscopy As A Detection Mode For Microfluidic Separations And Fluid Handling: Μfluidic-Sers, Raynella Magdalene Connatser

Doctoral Dissertations

The arena of microfluidics (µfluidics) has grown over the past decade to encompass myriad separation techniques and exploit copious detection modes. The direct integration of a vibrational spectroscopic detection technique, rich with structural information, onto a platform that is portable and potentially highly controllable such as µfluidics, could offer redress for some of the problems inherent in many of the electrophoretically driven separations carried out on said devices. Herein, this direct integration is explored, and methods of device fabrication, spectroscopic data collection conditions, analytical figures of merit of the detection technique, and separations method development results are discussed. The creation …

The Reaction Of Telechelic Polymers At Multicomponent Interfaces: A Molecular Loop Study, James Kevin Rice

Doctoral Dissertations

The work presented in this dissertation attempts to form an understanding of the reaction parameters that govern the reaction of telechelic polymers to form multiply bound polymer chains, resulting in polymer loop formation, at both soft and hard polymeric interfaces. Both theoretical and experimental studies offer evidence that blocky copolymers, as opposed to random or alternating morphologies, are the best compatibilizers of a given polymer blend system. This has been attributed to the fact that blocky copolymers spread across the interface, with each block lying in or near the homopolymer region in which it is miscible, effectively “stitching” the interface …

Multiple Approaches To The Separation Of Amino Acids And Biologically-Relevant Compounds, Lance Andrew Riddle

Doctoral Dissertations

The branch of analytical chemistry known as separations has continued to grow and expand ever since its beginnings a century ago. With all the technological advances occurring to make separations a more powerful technique, the main goal continues to be the desired separation of the compounds of interest in a mixture. Although a desired separation may be achieved, there can always be room for improvement with regards to the time necessary for the separation as well as better resolution of closely-related species as well as enantiomers of the same analyte.

In this work, a variety of separation methods and variations …

Synthesis And Radiolabeling Of Potassium Trifluoroborate Benzylidene Anabaseine Derivatives, Aaron Landon Smith

Doctoral Dissertations

Anabaseine has demonstrated a high, non-selective, affinity for the α7- bungarotoxin sensitive neuronal nicotinic acetylcholine receptor binding site found in small cell lung carcinoma. The benzylidene anabaseine derivatives of anabaseine have shown a selective affinity for these binding sites. These studies suggest that radiolabeled benzylidene anabaseine derivatives could act as potential imaging agents to aid in the early detection of lung cancer.

This dissertation outlines the strategy and methods employed in the synthesis of a family of potassium trifluoroborate derivatives of benzylidene anabaseine and their subsequent halogenation. Two of the trifluoroborate salts were converted to their radiolabeled analogues for potential …

Adsorption Of Small Molecules On Mgo And Graphite, Peter Nikolaivich Yaron

Doctoral Dissertations

The physical adsorption of molecules on metal oxide surfaces has direct implications in a number of industrial applications such as; catalysis, electronics, and fuel cells to name a few. Despite the large number of adsorption studies to date, only a small number of systems can be explained with the most advanced ab initio calculations currently available.

One of the simplest metal oxide systems to study is magnesium oxide due to its simple cubic rock-salt structure. Using a patented method, nearly defect-free MgO cubes can be synthesized with a narrow size distribution exposing exclusively the (100) equilibrium crystal face. The use …

Expression And Characterization Of Hyperthermophilic Aqujfex Pyrophilus Flagellin Protein In Mesophilic Bacterial Systems, Srivani V. Mukkamala

Masters Theses

The structural protein flagellin, FlaA derived from hyperthermophilic Aquifex pyrophilus, a rod shaped eubacterial species that grows near hydrothermal vents at an optimum growth temperature of 85 °C forms elongated thermostable flagella nanotubes. FlaA was successfully over-expressed for the first time using pET28c plasmid in E. coli BL21 cells at 37 °C. The protein was isolated from inclusion bodies that were solubilized by alkaline pH, refolded by dialysis and purified by chromatographic techniques. The FlaA was characterized by fluorescence, light scattering and circular dichroism. The FlaA was not in the correct folded form to form flagella as efforts to …

Synthesis And Characterization Of Complex Polymer Architectures, Brandon Scott Farmer

Doctoral Dissertations

Anionic polymerization based upon high vacuum technique has been used to synthesize different star polymers using varying linking techniques. In particular chlorosilanes, divinylbenzene, and polyhedral oligomeric silsesquioxane (POSS) chlorosilane derivatives were used in the synthesis of star polymers. These polymers, along with polymers synthesized by others, have been characterized by a range of methods in this work.

A series of polyisoprene (PI) stars were synthesized from dimethylaminopropyllithium (DMAPLi) and subsequently hydrogenated to form poly (ethylene-co-propylene) (PEP) these were characterized by size exclusion chromatography (SEC) coupled with online two angle laser light scattering (TALLS). These polymers were synthesized in an attempt …

Surface Modification Of Pigments And Its Role In Offset Ink Setting, Wei Gu

Electronic Theses and Dissertations

Ink setting affects offset print quality issues such as print mottle and print gloss. It is known that ink setting depends on many factors, such as the nature of the substrate, the properties of the coating, and the ink formulation. However, the role of pigment surface chemistry in offset ink setting is unknown. From an experimental perspective, it is difficult to determine the role of the surface chemistry as it requires paper coatings that are similar in physical properties and differ only in the pigment surface chemistry. The aim of this study was two-fold. The first was to apply methods …

Synthesis And Fundamental Characterization Of Nanoparticles And Their Clusters, Ke Du

Dissertations

Nanoparticles of gold derivatized with monolayers of thiocarboxylic acid ligands, core/shell nanoparticle composites of gold and silica, gold-glutathioneclusters, and titania nanoparticles were synthesized and their surface properties (extent of ligand coverage, net negative charge, and zeta potential) characterized by capillary electrophoresis as a function of pH, ionic strength, and dielectric constant for the first time. The hydrodynamic radii of thenanoparticles were determined by dynamic laser light scattering and used to calculate the net surface charge, extent of ligand coverage, and zeta potentials ofthe nanoparticles from electrophoresic mobilities. The ligand derivatized nanoparticles had similar hydrodynamic radius of about 20 nm which …

Synthesis And Characterization Of Inosamines, Sing Raj Gurung

Masters Theses

This project is concerned with the preparation of scyllo-inosarnine hydrochloride 6, a biologically active compound, which bears six successive stereogenic centers. The synthesis of this compound would help elucidate the involvement of inosamines in biological nitrogen fixation. myo-Inositol served as the starting material to synthesize target compound 6. Regioselective protection and deprotection of myo-inositol provided azide 43 as key intermediate. In the final steps deprotection of five benzyl groups and reduction of azido group was achieved by catalytic hydrogenation. scyllo-Inosamine hydrochloride 6 was fully characterized by m.p., ¹H NMR, ¹³C NMR, IR, EA and via …

Production Of Ethanol From Hardwood, Jay Mitchell

Electronic Theses and Dissertations

Diminishing crude oil and natural gas supplies, along with concern about greenhouse gas are major driving forces in the search for efficient renewable energy sources. The conversion of lignocellulosic biomass to energy and useful chemicals is a component of the solution. Ethanol is most commonly produced by enzymatic hydrolysis of complex carbohydrates to simple sugars followed by fermentation using yeast.

C₆H_l0O₅ + H₂O −Enxymes→ C₆H₁₂O₆ −Yeast→ 2CH₃CH₂OH + 2C0₂

In the U.S. corn is the primary starting raw material for commercial ethanol production. …

Development Of Novel Synthetic Methods Utilizing Organometallic Reagents And Total Synthesis Of Eupomatilone 2, Chunlan Chen

Masters Theses

This dissertation summarizes the development of novel synthetic methods involving organometallic reagents and their application in the total synthesis of the natural product eupomatilone 2. These newly discovered reactions include the palladium-catalyzed cross-coupling of allyl acetates with organosiloxanes and the diastereoselective synthesis of cis- and trans-a-methylene-y-lactones utilizing Baylis-Hillman adducts as precursors. Another important aspect of the research is the application of some of the methods in total synthesis of eupomatilone 2.

The new synthetic methodologies involving organometallic reagents developed in this dissertation are important transformations in modern organic synthesis. Mild reaction conditions, tolerance of various organic functional groups, and high …

Development Of Methods For The Study Of Phosphoproteins, Zhaoyuan Chen

Theses and Dissertations

Characterization of phosphoproteins-including detection, identification of phosphoproteins and identification of phosphorylation sites-is mostly done with radiolabeling and proteomic techniques. Three main topics related to phosphoprotein characterization are included in this dissertation. First, large-scale characterization of the CHO (Chinese hamster ovary) cell phosphoproteome was done using two dimensional gel electrophoresis (2DE) separation, visualization of phosphoproteins by radiolabeling or a phosphoprotein specific dye, followed by MALDI-TOF identification. Because radiolabeling of phosphoproteins is very sensitive and straightforward to quantify, such analysis can give a clear picture of the relative phosphosphorylation of proteins present in a sample. But there are also limitations to this …

Applications Of Mass Spectrometry To Synthetic Copolymers, Elizabeth Angela Stewart

Masters Theses

Over the last decade, application of mass spectrometry has grown immensely especially in polymer characterization. The focus of this thesis is to assess and extend the applicability of matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) and electrospray ionization mass spectrometry (ESI MS) in the analysis of synthetic copolymers.

Characterization of a non-ionic copolymer was attempted. The copolymer was styrene-co-maleic anhydride, which is in a class of copolymers that are used for commercial applications where low viscosity, high polarity and/or high reactivity are needed. MALDI-TOF MS was employed to obtain weight and number average molecular weight values (M_w and …

Regulation Of A Dna-Compacting Plastid Nucleoid Protein, Steven William Adamson

Dissertations

DCP68, a DNA-compacting nucleoid protein, was further characterized in order to understand how plastid nucleoid proteins affect the structure and function of chloroplast DNA. Previously, DCP68 was identified as ferredoxin: sulfite reductase, an enzyme that participates in reductive sulfur assimilation and inhibits chloroplast DNA replication and transcription in vitro [1, 2]. In this study, the portion of SiR that was found to be present in soluble and plastid nucleoid-enriched fractions indicated that most SiR was stromal in Arabidopsis and soybean plants. Although SiR was detected in Arabidopsis chloroplast nucleoid-enriched fractions, the study of nucleoid dynamics proved to be difficult due …

The Interaction Between Hydrogen And Various Carbon Allotropes Calculated Using Bond-Order Potentials, Michael Knippenberg

All Dissertations

Carbon-based materials are an exciting component of materials science. The understanding of interactions at the atomic level provide useful information for creating materials with specific properties. This dissertation examines three hydrocarbon systems: amorphous carbon (with and without hydrogenation), hydrogen adsorption in carbon nanotubes, and reconstructions of the diamond surface.
A melting/quenching procedure is used to produce amorphous carbon films at 2.0, 2.6, and 3.0 g/cm³. The sp³ fraction at each density is calculated and found to be qualitatively similar to experimental data at low densities. The inclusion of hydrogen in the amorphous film causes the sp^{3 …}

Capillary Electrophoresis Of Proteins With Selective On-Line Affinity Monoliths, Jenny Marcela Armenta Blanco

Theses and Dissertations

The analysis of proteins in biological fluids by capillary electrophoresis (CE) is of interest in clinical chemistry. However, due to low analyte concentrations and poor concentration limits of detection (CLOD), protein analysis by this technique is frequently challenging. Coupling preconcentration techniques with CE greatly improves the CLOD. An on-line preconcentration-CE method that can selectively preconcentrate any protein for which an antibody is available would be very useful for the analysis of low abundance proteins and would establish CE as a major tool in biomarker discovery. To accomplish this, an on-line protein G monolithic preconcentrator CE system for enrichment and separation …