Physical Sciences and Mathematics Commons^™

Physical Adsorption Of Ethylene On Mgo(100): Effects Of Substrate Ionicity And Symmetry On Wetting, Andi Barbour

Doctoral Dissertations

The wetting behavior of ethylene adsorbed on MgO(100) was investigated from 83{ 135 K using high resolution volumetric adsorption isotherms. Layering transitions for ethylene on MgO(100) are observed below the bulk triple point at 79.2 K and 98.4 K, respectively. From these isotherms, thermodynamic quantities associated with physical adsorption are determined. It was found that the average area occupied by ethylene on MgO(100) is around 22.6 squared angstroms per molecule. Using the two dimensional isothermal compressibility, the location of two potential phase transitions are identified at 108.6 K and 116.5 K for the first and second layer, respectively. The potential …

Studies Of Tungsten Alkyl Alkylidyne Compounds And Iron Porphyrin Derivatives, Brenda Ann Dougan

Doctoral Dissertations

This dissertation focuses on two research projects. The first project examines the reactions of tungsten(VI) alkyl alkylidyne and bis-alkylidene complexes with phosphines and water and the studies of thermodynamics and kinetics of the reactions. These studies have been conducted in part to determine the mechanistic pathway in the formation of novel tungsten(VI) species. The second portion of this dissertation focuses on the spin density and structures of biomimetic Fe(III) porphyrin derivatives using neutron and X-ray diffraction techniques. The spin density and magnetic properties of an Fe(III) porphyrin derivative has been determined by polarized neutron diffraction.

In the first portion of …

The Design And Synthesis Of Biotinylated Tylophorine Analogues For Use As Affinity Probes In The Elucidation Of The Cellular Targets Of Dcb-3503, Samson Francis

Doctoral Dissertations

The tylophorine analogue, DCB-3503 (1-62b, NSC-716802), has been found to exhibit broad spectrum activity in vitro in the National Cancer Institute’s (NCI) panel of 60 human-derived cell lines. Recent studies involving HepG2, a human hepatocellular carcinoma cell line, and two pancreatic ductal carcinoma cell lines (PANC-1 and HPAC), have suggested that DCB-3503 (1-62b) exerts its unique growth inhibition properties by modulating nuclear factor kappa B activity as well as through the inhibition of nuclear protein synthesis. However, the physiologically relevant protein binding partner(s) of DCB-3503 (1-62b) have not been identified. Herein, the design and …

Synthesis And Characterization Of Branched Polyelectrolytes: Star-Branched Napss, Daniel W. Holley

Doctoral Dissertations

In this thesis, we examined the effect of branching on the solution characteristics of polyelectrolytes using a set of star-branched NaPSS. The polystyrene precursors to these polyelectrolytes were synthesized using anionic polymerization allowing for the production of three distinct groups of star-branched polystyrenes with varying functionality and arm length.

Following sulfonation, several methods commonly employed in the literature for evaluation of sulfonation degree we established that sulfonation was quantitative. TGA was also demonstrated to reveal important characteristics of the sample.

We used aqueous SEC coupled with a multiple angle light scattering detector to determine several molecular characteristics of the star-branched …

Design And Synthesis Of Novel Tylophorine Analogs And Their Biological Activity, Julio Gutierrez

Doctoral Dissertations

Alkaloids containing the nitrogen atom in the bridgehead position of two rings, such as indolizidine, pyrrolizidine, and quinolizidine alkaloids, have a wide and varied distribution in nature. Some of these alkaloids demonstrate a broad range of pharmacological activities and have generated substantial synthetic interest. This thesis covers the total synthesis of novel tylophorine analogs called DCB 3503, DCB 3506, DCB 3507, DCB 3508, DCB 3509, and a derivative with a biotinylated chain attached to DCB 3506 for use as a biological probe. This thesis discusses the biological activity of these compounds as well.

Computational Exploration Of The Interaction Of Molecular Hydrogen With An Anionic Hydrogen Atom, Patrick Karl Moehlen

Doctoral Dissertations

The focus of this dissertation is to facilitate the computation of the infrared absorption line shape of solid para-hydrogen with an anionic hydrogen atom dopant. For this, we compute the complete potential energy surface for the interaction of H¯ with H². The coupled cluster with singles, doubles, and perturbative treatment of triple excitations method was used with augmented correlationconsistent polarized valence triple-zeta atom-centered basis sets and a set of bonding functions.

The focus then turns to describing the rovibrational Hamiltonian of the system with the coupledchannel method. We find bound and quasi-bound stationary states of the system for …

Development Of A Novel Lysophosphatidic Acid Activity Probe To Identify And Characterize New Protein Targets, Leah M. Cuthriell

Masters Theses

Lipids are categorized according to their biological function. Phospholipids, glycolipids, and cholesterol are bulk membrane lipids that offer structure and support to the cells and organelle membranes. Signaling lipids include diacylglycerol, phosphatidic acid, and lysophosphatidic acid (LPA). These are low abundance lipids that are active in various pathways. LPA acts through GPCR receptors to activate G or beta mediated stimulation of phospholipase C leading to phosphatidylinositol-(4,5)-bisphosphate hydrolysis, G_i mediated inhibition of adenyl cyclase, and G_i mediated stimulation of the mitogenic Ras- MAP kinase. To further elucidate the biological activity of LPA and potentially identify new LPA binding receptors, …

An Investigation Into The Activities Of 1,2,3 & 1,2,4 Triazoles In Biological And Catalytic Systems, David John Schneider

Masters Theses

Selective epigenetic control of the cellular machinery is a grail of drug development. The balance between HAT’s and HDAC’s activities is one way the cell controls what, and at when during the cellular lifecycle a gene is expressed. Having the ability to lock chromatin down to the histone is a powerful tool for the treatment of disease states like cancer. Presented here is a preliminary exploration of the synthesis, and basic testing of novel compounds that use a triazole motif as a zinc binding group in an attempt to gain further selectivity in inhibition over HDAC’s.

Interest in the development …

The Impact Of Iron Deprivation On The Metabolism Of Escherichia Coli As Measured By Targeted Hplc-Ms/Ms Based Metabolomics, Jamie Rhea Light

Masters Theses

Iron is a necessity for all living organisms, and bacteria typically need an internal concentration of iron in the micromolar range.¹ This becomes quite problematic, especially in pathogenic bacteria, because the concentration of free ions within the human body is only 10^-24 Molar due to iron binding proteins, like transferrin.¹ In order to circumvent this problem, bacteria produce small iron chelating molecules called siderophores.¹ The bacteria utilized for this study, a K-12 derivative of Escherichia coli, produce only one siderophore, enterobactin. Not only is the transcription of genes associated with iron acquisition initiated in response …

Design And Synthesis Of Fret-Based Boronic Acid Receptors To Detect Carbohydrate Clustering And Development Of Diacylglycerol-Based Lipid Probesto Investigate Lipid-Protein Binding Interactions, Manpreet Kaur Cheema

Masters Theses

Carbohydrate–protein interactions play vital roles in various biochemical processes such as signal transduction and cell surface recognition events. The clustering of carbohydrates into dense domains such as lipid rafts regulates recognition by multivalent receptors (i.e. lectins). These regions are known to play important roles in biological processes such as cellular transduction and trafficking. In order to characterize the clustering of glycans on cell surfaces, detection of domains with high carbohydrate density is of great interest. In this thesis, we present the work based on a modular strategy to design and synthesize boronic acid-based carbohydrate receptors, which are termed as boronolectins …

Spectroscopic Imaging For The Detection And Identification Of Bacterial Contaminations, Michael Gilbert

Doctoral Dissertations

There exist many types of harmful bacteria that can contaminate foods and cause serious illness, which often have their own best courses of treatment. This requires the classification of different types of bacteria. Traditional methods of bacterial identification, while able to provide accurate classification, are often very time-consuming processes. In the case of a potentially fatal bacterial infection, time is often of the essence. FTIR spectroscopy is a faster, more practical alternative that can discriminate different strains of bacteria, based on their spectral signatures, with high confidence.

Bacterial contaminations on food exist as small, localized colonies that must be found …