Physical Sciences and Mathematics Commons^™

Preparation Of Divalent And Trivalent Antigens For Immunogical Studies On Degranulation Of Mast Cells And Preparation Of Ceragenins For Antiviral Studies Against Vaccinia Virus., Dianliang Geng

Theses and Dissertations

CHAPTER 1

Aggregation of receptors for IgE (Fc RI) causes mast cells and basophils to release preformed contents of granules, including histamine and a variety of enzymes. This process, called degranulation plays a central role in allergic reactions. Methods to study this process are to create multivalent ligands which can interact with the receptors and, in turn, lead to aggregation of the receptors. We prepared a series of fluorophore-labeled divalent and trivalent antigens to study the degranulation of mast cells. Trivalent antigens proved to be much better stimulators for degranulation of mast cells than divalent antigens. These results indicate that …

Pyridinium Bisretinoids: Synthesis And Photoactivated Cytotoxicity, Junping Gao

Theses and Dissertations

This thesis discusses pyridinium bisretinoid compounds (PBRs), which were prepared for two purposes: 1) to use them as standards for detection of novel fluorophores in human RPE cells, which may be involved in age-related macular degeneration (AMD), and 2) to use them in the development of a targeted and triggered drug delivery system for cancer therapy. We prepared a selection of PBRs using a one-pot biomimetic method; synthesis, mechanisms for formation, and characterization of these compounds is described. We also explored the photoreactivity of three novel PBR compounds and found that these PBRs form oxidation products under blue-light irradiation. The …

Study Of The Reproducibility Of Proteomics Methods And Variability Of Fruit Fly Proteomes., Thomas Franklin Culwell

Theses and Dissertations

The reliability of biomarker discovery by means of proteomics has been called into question. It was speculated that "background noise" variation resulting from differences in preparation and handling of samples and proteome dynamics may mask subtle, yet important, differences due to the biological condition. Little is understood about complex proteomes and their variability. A critical aspect of proteomic biomarker research that is largely unexplored is the comparative reproducibility of certain methods such as two-dimensional gel electrophoresis and liquid chromatography/mass spectrometry. In particular, with liquid chromatography/mass spectrometry, it is not known whether variability in peptide quantitation is dependent on any of …

Pyridinium Bis-Retinoids A2-Dopamine And A2-Cadaverine: Implications In Age-Related Macular Degeneration And Cancer, Mckenzie Ruth Pew

Theses and Dissertations

Age-related macular degeneration (AMD) is the leading cause of blindness in the United States of America. The pyridinium bis-retinoid A2-ethanolamine (A2E) has been implicated to play a role in AMD. We have observed novel pyridinium bis-retinoids through melanolipofuscin and human RPE extractions that may also play a role in the pathology of AMD. We have begun the construction of an amino-retinoid library in order to identify these ocular compounds. The compounds from the amino-retinoid library are also used in a targeted and triggered drug delivery system for treating cancer. Folic acid is coupled with the amino-retinoids to specifically target cancer …

Thermodynaimic Study Of Nucleic Acids Recognition By Aminoglycosides , Hongjuan Xi

All Dissertations

ABSTRACT


Since the origin of first aminoglycosides antibiotics, streptomycin, isolated by Selman Waksman about 60 years ago, a number of aminoglycosides antibiotics were discovered to treat different infections. Neomycin class aminoglycosides were found to originally target the A site 16S rRNA in the 30S subunit of the ribosome within the Gram-negative bacteria. In addition to its antibacterial effect, aminoglycosides were also found to binding to various other viral RNA structures such as TAR and RRE of HIV, Group I introns and hammerhead ribozyme, implying its potential to be used as antiviral reagent.

Furthermore, previous studies in our laboratory discovered a …

Lithium-Conducting Ionic Melt Electrolytes From Oligomeric Ethylene Glycols: Synthesis And Characterization, Boutros Hallac

All Dissertations

Commercial lithium ion cells consist of electrolytes that undergo salt concentration polarization which is acute upon high discharge currents. This type of polarization occurs as a result of the mobility of more than one ionic species in the presence of an electric field. One way to overcome it is by employing a material that would allow the mobility of one ionic species. This thesis will describe the synthesis and characterization of several fluorosulfonimide and fluorosulfonate based ionic liquids/melts as electrolytes having lithium as the only mobile ion. These materials were prepared by the nucleophilic addition reaction of a deprotonated polyether …

Studies Of The Stability And Potential Applications Of Pyrrolidinofullerenes And Other Fullerene Derivatives, Olena Lukoyanova

All Dissertations

Over the last decade, the variety of chemically modified fullerenes and their potential applications has increased significantly. Among fullerene derivatives, pyrrolidinofullerenes are one of the most widely synthesized types since they can be easily and efficiently obtained via simple reactions from both empty and endohedral fullerenes. Although fullerenes in general and pyrrolidinofullerenes in particular have been considered for numerous applications in electronic and optoelectronic devices, photovoltaics, medicinal chemistry, etc., their potential application in the evolving field of molecular electronics has not been extensively explored. The envisioned role of the fullerenes usually involves storage or transport of electrons. Therefore, studies of …

Development Of Fullerene Based Sturctures For Photovoltaic And Electronic Applications, Amit Palkar

All Dissertations

Solar energy can be envisioned as a long term alternative to rapidly depleting fossil fuels. The energy from the sun can be harnessed by constructing donor-acceptor (D-A) type devices where the incident photon induces the transfer of an electron from the donor to the acceptor. If recombination is prevented, this electron can then be channeled through an external circuit, thus leading to the generation of photocurrent. Porphyrins, which are the naturally occurring pigments in photosynthesis, have been widely established as donors while fullerenes, such as C₆₀ and C₇₀ , due to their unique electron accepting properties, have been …

Effects Of Water Vapor On The Kinetics Of The Methylperoxy Radical Self-Reaction And Reaction With Hydroperoxy, Alecia Mower

Theses and Dissertations

The gas phase reactions of CH3O2 + CH3O2, HO2 + HO2, and CH3O2 + HO2 in the presence of water vapor have been studied at temperatures between 263 and 303 K using laser flash photolysis coupled with UV time-resolved absorption detection at 220 nm and 260 nm. Water vapor concentration was quantified using tunable diode laser spectroscopy operating in the mid-IR. The HO2 self-reaction rate constant is significantly enhanced by water vapor, consistent with what others have reported, whereas CH3O2 self-reaction and the cross-reaction (CH3O2 + HO2) rate constants are nearly unaffected. The enhancement in the HO2 self-reaction rate coefficient …

Total Synthesis Of An Analog Of Hydramycin And Derivatization Of Thiol-Terminated Carbohydrates And Development Of A Glycoconjugate Too Set For The Assembly And Presentation Of Carbohydrate Ligands On Surfaces, Medhanit Woldeghiorghis Bahta

Doctoral Dissertations

2-(1,2-Dihydroxy-1-(oxiran-2-yl)ethyl)-11-hydroxy-5-methyl-1Hnaphtho[ 2,3-h]chromene-4,7,12-trione (1), a pyranoanthraquinone isolated from Streptomyces violaceus P950-4, showed a potent antibacterial and cytotoxic activity. A model synthesis for analogs 2-(1,2-dihydroxy-1-(oxiran-2-yl)ethyl)-4H-chromen- 4-one (2) and2-(1-hydroxy-1-(oxiran-2-yl)ethyl)-1H-naphtho[2,3- h]chromene-4,7,12-trione (3) was developed by Dr. David White and Dr. Sarah Headrick. A new analog, 2-(1,2-dihydroxy-1-(oxiran-2-yl)ethyl)-1H-naphtho[2,3- h]chromene-4,7,12-trione (4), was designed to be structurally more similar to hydramycin with –CH2OH functionality on the pyranone ring and anthraquinone skeleton. Therefore, it is expected to have greater anticancer activity than either analogs 2 or 3. This dissertation will cover developments, challenges and solutions in …

Electroanalysis Of Metals In Biological And Environmental Samples At Bismuth Electrodes, Kristie Carter Armstrong

Doctoral Dissertations

An Advanced Oxidation Process (AOP) was designed for the decomposition of organic material in blood as a pretreatment for chromium analysis. Acidified porcine blood was treated with hydrogen peroxide and UV light for 60 min. The rate of decomposition was studied using UV/Vis spectroscopy. It was found that the order of the photolytic reaction with respect to hydrogen peroxide was 0.35. The pretreated blood was subsequently analyzed for chromium content by catalytic adsorptive stripping voltammetry at a bismuth film electrode. The concentration of chromium was determined to be 6.0 " 0.3 parts per billion (ppb). A bismuth bulk electrode was …

Nanomaterial Composites For The Detection Of Nerve Gas Analogs, Yogesh Datar

Masters Theses

The basis of the research work described here is the use of nanocomposite materials built by bottom-up approach for the selective detection of nerve gas analogs. Nanocomposites materials constructed by using nanoparticle-monomer-receptor (NMR) concept have been utilized to detect nerve gas analogs DCP and DMMP. Synthetic approach used in the construction of nanosensors involved use of robust platforms such as silica nanoparticles and fluorescent quantum dots. Highly conjugated receptor molecules were synthesized by using stilbeneoid compounds. A complete opto-nanosensor was developed by anchoring highly conjugated receptor molecules onto the silica nanoparticles as well as onto the quantum dots. The opto-nanosensors …

Synthesis, Study Of Self-Assembly, And Trivalent Lanthanide Metal Ion Recognition Characteristics Of Amphiphilic Acylpyrazolones And Amphiphilic Acylisoxazolones, Venkat Reddy Guduru

Dissertations

This research project focused on the separation of trivalent lanthanide metal ions by HPLC using amphiphilic acylpyrazolones and amphiphilic acylisoxazolones. The central hypothesis of our research project is that the nanoscale self-assembly nature of amphiphilic ligands (chelating lingads) can influence their metal ion recognition and separation. To test the central hypothesis, we have synthesized a family of novel amphiphilic ligands and employed them as model systems for the separation of trivalent lanthanide metal ions. Several novel intermediates such as 4-acylated. N -acylated, O -acylated pyrazolones and isoxazolones, have been efficiently synthesized and fully characterized.*

The trivalent lanthanide metal ion recognition …

Synthesis And Characterization Of Ruthenium Bipyridyl Complexes For Detecting Nerve Gas Agents And Explosives, Arambe Gedara Aruna Weerasinghe

Masters Theses

Five novel 2,2 '-bis bi pyridine Ru(II) complexes have been synthesized and characterized using ¹H NMR, ¹³C NMR, ¹H-¹H-COSY, elemental analysis, fast atom bombardment or electrospray mass spectra and electronic absorption spectroscopy. Binding of Ru (11) complexes with nerve gas analogos such as diethyl chlorophosphate (DCP), dimethyl methyl phosphonate (DMMP) and hydrolyzed product (HCl) has been investigated by electronic absorption, fluorescence, and lifetime studies. Compound 1 showed a quenching in ³MLCT emission after an initial increase in intensity upon the addition of DCP with a bathochromic shift of 25 nm. Compound 2 exhibit a …

Design Of Multi-Electron Transfer Catalysts For The Reduction Of Trichloroethylene, Christopher Gerard Eman Ciptadjaya

Masters Theses

For decades, organohalide (RX) compounds have been heavily used in the chemical and pharmaceutical industries and in agriculture as pesticides. Improper disposal of organohalides has resulted in their presence in the environment as pollutants, and they have therefore presented serious environmental and toxicological concerns. These organohalides have been associated with various health and environmental problems. Therefore, effective methods for their remediation are required. We have developed a multi-electron transfer (MET) catalyst consisting of flavin mononucleotide anchored to nanocrystalline mesoporous titanium dioxide (TiO₂) thin films, and examined its reactivity toward the organohalide pollutant trichloroethylene (TCE). Various environmental factors were …

Alkoxide Routes To Inorganic Materials, George Harrison Thomas

Doctoral Dissertations

An all alkoxide solution chemistry utilizing metal 2-methoxyethoxide complexes in 2-methoxyethanol was used to deposit thin-films of metal oxides on single-crystal metal oxide substrates and on biaxially textured metal substrates. This same chemistry was used to synthesize complex metal oxide nanoparticles. Nuclear Magnetic Resonance spectroscopy was used to study precursor solutions of the alkaline niobates and tantalates. Film crystallization temperatures were determined from X-ray diffraction patterns of powders derived from the metal oxide precursor solutions. Film structure was determined via X-ray diffraction. Film morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM).

Epitaxial thin-films of strontium …

Synthesis And Characterization Of Stilbenoids And Their Aza-Analogs As Photoluminescent Materials For The Detection Of Nerve Agent Mimics, Chun Wang

Dissertations

A novel series of stilbenoids and their aza analogs were synthesized, characterized and used as photoluminescent components in the detection of nerve agents. Their structure-property relationship was elucidated through UV-visible and fluorescence spectroscopy. The research in this thesis is driven by the hypothesis that the two-block sensor system consisting of a receptor incorporated ruthenium complex and a fluorescent signal molecule of stilbenoids, is capable of detecting chemical warfare agents. The sensor anchored onto nanoparticles and subsequently the nanoparticles were arranged through mediated self-assembly. While photo-induced electron transfer is a well-known mechanism for sensor design, the described system showed that photo-induced …

Nanosensors For The Detection Of Nerve Agents And Explosives, Deepak Kumar Thimmaraju

Masters Theses

The central hypothesis of this research was development of a novel nanosensor for the detection of nerve agents and explosives. The nanosensor assembly comprises a bottom up approach with nanoparticle (N), monomer (M), nanomolecule (N) and a receptor (R) as moieties of a NMNR assembly. My research was focused on evaluating receptors for their efficiency towards the target analytes such as nerve agents and explosives. Pi electron rich receptor 2-Phenyl-2-Propanol and its fluorinated analog 1,1,1,3,3,3-Hexafluoro-2-Phenyl-2-Propanol were investigated for their ability to detect nerve agents such as DCP, its analogs DMMP and HCl along with the explosives mono, di, and trinitrotoluene. …

Technical Evaluation Of Hardwood Biorefinery Using The "Near-Neutral" Hemicellulose Extraction Process, Haibo Mao

Electronic Theses and Dissertations

A technical analysis was performed for a new process that produces ethanol and acetic acid from hardwood in addition to bleached hardwood Kraft pulp. The new process, termed the "near neutral" hemicellulose extraction process, involves the extraction of wood hemicellulose using green liquor prior to conventional Kraft pulping. This thesis assumes that the new process is located at an existing kraft pulp mill. Ancillary unit operations in the process include hydrolysis of the extracted carbohydrates using sulfuric acid, filtration of the extract to remove lignin that was extracted with the carbohydrates, liquid-liquid extraction of acetic acid and by-product furfural, liming …

Fundamental Investigation Of Vesicle Bilayer Membrane Dynamics, Wilson Okumu

Masters Theses

We studied the bilayer of vesicles from dimyristolyphosphatidylcholine (DMPC), using nitrobenzoxadiazole (NBD) probes, attached to the head (NBD-PE) and the tail (NBD-PC) of phospholipid derivatives. We characterized the bilayer as it underwent reversible transition from the gel to the fluid through a phase transition range. The main phase transition was characterized by steady state and timeresolved fluorescence anisotropy, fluorescence intensity decrement and kinetics of dithionite reduction. We also studied DMPC with dihydrocholesterol. Differences between the surface and interior regions of the bilayer region were obtained. The activation barrier was enthalpic in the gel, entropic in the fluid phase and anomalous …

Electrokinetic Modeling Of Free Solution Electrophoresis, Yao Xin

Chemistry Dissertations

Modeling electrophoresis of peptides, proteins, DNA, blood cells and colloids is based on classical electrokinetic theory. The coupled field equations-Poisson, Navier-Stokes or Brinkman, and ion transport equations are solved numerically to calculate the electrophoretic mobilities. First, free solution electrophoretic mobility expressions are derived for weakly charged rigid bead arrays. Variables include the number of beads (N), their size (radius), charge, distribution (configuration), salt type, and salt concentration. We apply these mobility expressions to rings, rigid rods, and wormlike chain models and then apply the approach to the electrophoretic mobilities and translational diffusion constants of weakly charged peptides. It is shown …

Exploring The Role Of Calcium Ions In Biological Systems By Computational Prediction And Protein Engineering, Yubin Zhou

Chemistry Dissertations

Ca2+, a signal for death and life, is closely involved in the regulation of numerous important cellular events. Ca2+ carries out its function through its binding to Ca2+-receptors or Ca2+-binding proteins. The EF-hand protein, with a helix-loop-helix Ca2+-binding motif, constitutes one of the largest protein families. To facilitate our understanding of the role of Ca2+ in biological systems (denoted as calciomics) using genomic information, an improved pattern search method (http://www.chemistry.gsu.edu/faculty/Yang/Calciomics.htm) for the identification of EF-hand and EF-like Ca2+-binding proteins was developed. This fast and robust method allows us to analyze putative EF-hand proteins at the genome-wide level and further visualize …

Microchip Liquid Chromatography And Capillary Electrophoresis Separations In Multilayer Microdevices, Hernan Vicente Fuentes

Theses and Dissertations

In this dissertation, several microfabricated devices are introduced to develop new applications in the area of chemical analysis. Electrochemical micropumps, chip-based liquid chromatography systems and multilayer capillary electrophoresis microdevices with crossover channels were fabricated using various substrates such as poly(dimethylsiloxane) (PDMS), glass, and poly(methyl methacrylate) (PMMA). I have demonstrated pressure-driven pumping of liquids in microfabricated channels using electrochemical actuation. PDMS-based micropumps were integrated easily with channel-containing PMMA substrates. Flow rates on the order of ~10 µL/min were achieved using low voltages (10 V). The potential of electrolysis-based pumping in microchannels was further evaluated for pressure driven microchip liquid chromatography (LC). …

Microfluidic Electro-Osmotic Flow Pumps, John Mason Edwards

Theses and Dissertations

The need for miniaturized, portable devices to separate and detect unknown compounds has greatly multiplied, leading to an increased interest in microfluidics. Total integration of the detector and pump are necessary to decrease the overall size of the microfluidic device. Using previously developed thin film technologies, an electroosmotic flow (EOF) pump was incorporated in a microfluidic liquid chromatography device. An EOF pump was chosen because of its simple design and small size. EOF pumps fabricated on silicon and glass substrates were evaluated. The experimental flow rates were 0.19-2.30 microliters/minute for 40-400 V. The theoretical pump efficiency was calculated along with …

Counter-Flow Ion Mobility Analysis: Design, Instrumentation, And Characterization, Nosa Agbonkonkon

Theses and Dissertations

The quest to achieve high resolution in ion mobility spectrometry (IMS) has continued to challenge scientist and engineers in the field of separation science. The low resolution presently attainable in IMS has continued to negatively impact its utility and acceptance. Until now, efforts to improve the resolution have mainly focused on better instrumentation and detection methods. However, since the resolution of IMS is diffusion limited, it makes sense to address this limitation in order to attain high resolution. This dissertation presents a new IMS technique, which utilizes a high electric field and opposing high gas flow velocity with the aim …

The Characterization Of Trna Modifying Enzymes S-Adenosylmethionine : Trna Ribosyltransferase-Isomerase (Quea) And A Novel Type I Gtp Cyclohydrolase, Shilah Amal Bonnett

Dissertations and Theses

Queuosine is a hypermodified nucleoside located in the wobble position of bacterial and eukaryotic tRNAs coding for Asp, Tyr, His and Asn. The biosynthesis involves the participation of S-adenosyl-methionine:tRNA ribosyltransferase-isomerase (QueA) and a GTP Cyclohydrolase-I. QueA catalyzes the transfer and isomerization of the ribosyl moiety from AdoMet to preQ1 modified tRNA. Substrate analogs of AdoMet were used to elucidate important substrate-enzyme interactions and to test key steps in the proposed chemical mechanism. Replacing AdoMet with SeAdoMet had little effect upon substrate binding but exhibited 30-fold reduction in kcat, consistent with deprotonation at C-5' as the first catalytic step. 7-deazaAdoMet failed …

Microcantilever Surface Modification For Chem-/Bio-Sensing, Hongwei Du

Doctoral Dissertations

One focus of the microcantilever (MCL) sensing area is to develop a novel surface modification approach to increase the microcantilever bending amplitudes and thus further improve sensitivities. In this dissertation, enzyme incorporated using the Layer by-Layer (LbL) process, LbL deposition of micro-, nano-hydrogel particles and electrophoretic deposition (EPD) of micro-, nano-hydrogel particles were applied to prepare a multilayer or thin hydrogel films on the surface of microcantilevers. Prior to applying to the microcantilevers, LbL and electrophoretic deposition techniques were also applied to gold coated silicon wafer surfaces to investigate the feasibility and deposition behavior using these techniques. The multilayers prepared …

A Computational Chemistry Study Of Spin Traps., Jacob Fosso-Tande

Electronic Theses and Dissertations

Many defects in physiological processes are due to free radical damage: reactive oxygen species, nitric oxide, and hydroxyl radicals have been implicated in the parthenogenesis of cancer, diabetes mellitus, and rheumatoid arthritis. We herein characterize the phenyl-N-ter-butyl nitrone (PBN) type spin traps in conjunction with the most studied dimethyl-1-pyrroline-N-oxide (DMPO) type spin traps using the hydroxyl radical. In this study, theoretical calculations are carried out on the two main types of spin traps (DMPO and PBN) at the density functional theory level (DFT). The energies of the optimized structures, hyperfine calculations in gaseous and aqueous phases of the spin traps …

Capillary Electrochromatography-Mass Spectrometry (Cec-Ms) Of Surfactants, Dean Stephen Norton

Chemistry Dissertations

This research presents advancements in the coupling of capillary electrochromatography (CEC) to mass spectrometry (MS) for the analysis of different chemical classes of surfactants. Chapter 1 provides a brief introduction that summarizes the mechanics and fundamentals of CEC, including instrumentation and applications for CEC-MS. Chapter 2 describes the on-line hyphenation of a packed CEC column with an internally tapered tip coupled to electrospray ionization-mass spectrometry (ESI-MS) and atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) for the analysis of betaine-type amphoteric or zwitterionic surfactants (Zwittergent®). The interesting aspects include CEC-MS column manufacture and charaterization, as well as a comparison between the CEC-ACPI-MS …

Mixed Quantum-Classical Molecular Dynamics Study Of A Hydrated Electron And An Investigation Of Temperature Control Algorithms, Janet Aremu-Cole

All Dissertations

The use of classical and quantum mechanics has been employed in this dissertation to study temperature control algorithms and a hydrated electron. A comparison of the effects of four commonly used temperature control algorithms on the energetics and dynamics of liquid water has been executed, in efforts to better understand the non-equipartitioning effects caused by some thermostats. The Berendsen, Andersen, Langevin, and velocity rescaling temperature control algorithms were applied to both dimer and bulk water systems, using the TIP4P water model. The two deterministic thermostats, Berendsen and velocity rescaling, display the 'flying ice cube effect' that had been noticed earlier …