Chemistry Commons^™

Patterning High Surface Area Silica With Lysozyme: Adsorption Kinetics, Fluorescence Quenching, And Protein Readsorption Studies To Evaluate The Templated Surface, Rachel M. Greer, Brittni A. Scruggs, R Alan May, Bert D. Chandler

Chemistry Faculty Research

A method was developed for using an inexpensive and widely available protein, hen egg white lysozyme, as a patterning agent for commercial high surface area silicas. The basic patterning methodology involved spontaneous adsorption of the protein from aqueous solution, alkylation of the uncovered surface with an alkylsiloxane, and protein desorption in a slightly alkaline solution of morpholine. Adsorption kinetic studies using Bradford assays assisted in determining protein deposition conditions. These studies were generally consistent with results on more planar silica surfaces and indicated that the protein quickly and strongly adsorbs along its long axis at low surface coverages. A modified …

Characterization And Transitions Of Asphalt Cement Composite Materials, Brent Harper Sellers

LSU Master's Theses

Blends of a PG 64-22 asphalt with a range of load levels (0.2 — 20 wt %) of Sasobit® wax and a single loading of 2 wt % Elvaloy AM® were prepared and characterized. Sasobit® wax is a high molecular weight paraffinic wax produced commercially through the Fischer-Tropsch process. Elvaloy AM® is a reactive elastic terpolymer, comprised of ethylene, butyl acrylate and glycidyl methacrylate monomeric units. The blends were analyzed by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), x-ray diffraction, epifluorescence microscopy, scanning laser confocal microscopy, and dynamic shear rheology. Sasobit (1 wt %) composite material showed little difference …

Studies On The Effect Of Natural Organic Matter And Hydration On The Sorption And Desorption Of Trifluorinated Pesticides, Charisma Vinarao Lattao

LSU Doctoral Dissertations

This work was done in order to deepen our molecular level understanding of how soil organic matter (SOM) is assembled in a whole soil and to provide further insight on the effect of SOM assembly on the uptake and release of hydrophobic organic compounds. Various techniques, including ultraviolet absorbance, fluorescence, and total carbon analysis, demonstrate that hydration/solvation of SOM is kinetically controlled. Initial wetting of a soil releases the hydrophobic moieties that are located at the outer surface of SOM, and longer wetting times exfoliate more hydrophobic quinone type moieties that are present in the middle layer, which in turn …

Scanning Probe Microscopy Investigations Of (1) Arrays Of Cysteine-Coated Cds Nanoparticles And (2) Structures Formed During The Early Stages Of The Corrosion Of Copper Surfaces, Brian Robert Lewandowski

LSU Doctoral Dissertations

Scanning probe microscopy (SPM) characterizations are becoming more prevalent for surface investigations due to their capabilities for obtaining structural information and physical measurements. New capabilities of SPM for studying and controlling nanoscale processes are emerging as valuable assets in research. A fundamental understanding of the interactions of surface reactions provides essential information for developing workable applications for nanotechnology. Two applications of SPM are discussed in this dissertation. The first investigation uses atomic force microscopy (AFM) for the characterization of nanostructures produced with a newly developed lithographic technique called “two-particle” lithography. This new technique is based on particle lithography for the …

Atom-Based Computer Simulation Studies Of Gas-To-Liquid Nucleation In Atmospherically Relevant Systems: Clarifying Discrepancies And Elucidating Mechanisms, Ricky Bendanillo Nellas

LSU Doctoral Dissertations

For over a century, nucleation for all systems was thought simplistically to be a process that advances through the formation of critical clusters with a well-defined composition. Our results show intriguing nucleation mechanisms that challenge the aforementioned notion. We employed the simple TraPPE-UA (transferable potential for phase equilibria – united atom) force field and the AVUS-HR approach (a combination of aggregation-volume-bias Monte Carlo, umbrella sampling, and histogram reweighting), to investigate the homogeneous vapor-to-liquid nucleation of various nucleating systems. We found out that these systems could nucleate through a variety of unique non-ideal mechanisms. Alongside existing experimental investigations, this dissertation presents …

Iron Mediated Pecipitation Of Phenol: Protein Aggregates From Sugar Cane Juice, Lee R. Madsen Ii

LSU Doctoral Dissertations

The Louisiana cane sugar industry is moving toward a vertically integrated arrangement where raw sugar producers will have an interest in refining. In the sugar refining process, raw sugar is affined to remove ~50 % of the color. The new refinery that will be built in Louisiana, however, will not include affining stations. To reduce costs of refining, either affining stations will need to be installed at each mill or new technologies that provide equivalent color reduction (~50% or ~750 IU) need to be implemented. As part of this dissertation a new technology for color reduction at raw sugar mills …

Fabrication Of Nanostructured Surfaces With Well-Defined Chemistry Using Particle Lithography, Jie-Ren Li

LSU Doctoral Dissertations

Natural self-assembly processes provide nanofabrication capabilities for designing surfaces with nanoscale control of surface chemistry and relative orientation of the nanomaterials on the surfaces. Particle lithography was used to produce periodic arrays of protein nanostructures. Monodisperse mesoparticles can be applied to rapidly prepare millions of uniform protein nanostructures on flat surfaces using the conventional benchtop chemistry steps of mixing, centrifuging, evaporation and drying. Nanopatterns of bovine serum albumin and staphylococcal protein A were produced with particle lithography. The immobilized proteins remain attached to the surface and form nanopatterns over micron areas corresponding to the thickness of a single layer of …

Qualitative Thm-Gc-Ms Analysis Of Proteins And Amino Acids In Rock Painting Binders, Melissa Doolin

Senior Honors Theses and Projects

A vital step to radiocarbon dating rock paintings involves the characterization of organic material in the paint. Using THM-GC-MS we have created a library of mass spectrometric data on possible organic binders, to compare to authentic paint samples. To reduce interference from contaminants and the mineral background, we are developing a simple purification technique to extract proteins and carbohydrates from these samples. Separating the organics can greatly enhance our results for GC-MS identification and subsequent radiocarbon analysis by accelerator mass spectroscopy.

Anthropogenic Osmium In Rain And Snow Reveals Global-Scale Atmospheric Contamination, Cynthia Chen, Peter N. Sedwick, Mukul Sharma

OES Faculty Publications

Osmium is one of the rarer elements in seawater, with typical concentration of ≈10 x 10^-15 g g^-1 ( 5.3 x 10^-14 mol kg^-1. The osmium isotope composition (¹⁸⁷Os/¹⁸⁸Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (≈ 1.3) and mantle/cosmic dust (≈ 0.13). Here, we show that the ¹⁸⁷Os/¹⁸⁸Os ratios measured in rain and snow collected around the world range from 0.16 to 0.48, much lower than expected (>1), but similar to the isotope composition of ores (approximate to 0.2) …

The Effects Of Exogenous Insulin And Exercise On Glucose And Lactate Metabolism In The Brown Anole, Anolis Sagrei, Kristen Marie Hitchcox

Honors Theses

Blood glucose homeostasis is tightly regulated in mammals. Insulin and exercise both stimulate glucose uptake into muscle cells via the GLUT4 transporter protein by independent pathways. Insulin triggers a tyrosine kinase pathway, but the mechanism stimulated by exercise is unknown. Discovering the mechanism may provide new therapeutic techniques for people with diabetes mellitus. While mammals have been studied extensively, research on a different model may elucidate aspects of this lesser known pathway. Reptiles rapidly deplete glycogen stores during bursts of activity and produce lactate as a byproduct of anaerobic metabolism. Lactate undergoes gluconeogenesis within muscle tissue, rather than liver tissue, …

Mechanisms Of Cytotoxicity Of Diepoxybutane, Epichlorohydrin And 1-(Chloroethenyl)Oxirane, Rebecca D. Kamins

Honors Theses

Diepoxybutane (DEB), epichlorohydrin (ECH), and 1-(chloroethenyl)oxirane (COX) are small molecules that can form DNA interstrand cross-links. All three of these compounds are, or are metabolites of, industrial chemicals linked to cancer. Additionally, DEB is a metabolite of treosulfan, an anti-cancer drug. We are trying to determine why some of these compounds cause cancer and some can also cure cancer. To do so, we are attempting to link cytotoxicity, cross-linking efficiency, and apoptotic potential of the three compounds to see if any correlations exist. The purpose of this project was to quantify apoptotic potential of DEB, ECH and COX. This was …

Changes In Apoptotic Gene Expression Induced By Dna Cross-Linkers, Jordanne B. Dunn

Honors Theses

The Millard Research Laboratory is interested in the cytotoxic mechanisms of the bifunctional alkylators diepoxybutane (DEB), epichlorohydrin (ECH), and (1-chloroethenyl) oxirane (COX). Studies performed in the laboratory examine the dual nature of these DNA cross-linking compounds that can act as carcinogens or anti-cancer agents. The mechanisms through which these compounds induce cell death are explored in this study. Cells either undergo cell death due to necrosis or apoptosis. HL-60 cells were treated with varying concentrations of DEB, ECH, or COX. A caspase 3/7 assay was used to test for induction of apoptosis in the treated cells at varying incubation times. …

Export Of Terrestrial Dissolved Organic Matter Along A River To Ocean Transect Of The Lower Chesapeake Bay Investigated By Advanced Analytical Techniques, Rachel Leigh Sleighter

Chemistry & Biochemistry Theses & Dissertations

Ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) has proved essential for the complete separation of the thousands of peaks present in natural organic matter (NOM), a complex assemblage of organic molecules present in water, soils, and sediments. An improved understanding of its composition is crucial to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles.

Optimizing the acquisition and handling of the FTICR mass spectra is the first step to obtaining high quality data. A simple method to internally calibrate the peaks in the complex spectra, using naturally present fatty …