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Determining Kinetics For Simulated Sunlight-Exposed Oil Compounds, Dustin D. Kountz

LSU New Orleans Theses and Dissertations

Understanding of the fate of oil in the environment is of utmost importance; however, accurate, predictive models are still in very early stages. To aid in the development of these models, photodegradation of selected polycyclic aromatic hydrocarbons (PAHs) in an n-alkane hydrocarbon matrix was followed for individual PAHs and mixtures of PAHs similar to that found in the Deepwater Horizon spill. Tetracene in tetradecane photodegraded quickest of all observed PAHs, with a loss of 99% after only one hour of irradiation. Binary mixtures of PAHs showed different degradation amounts, including changes in PAH kinetics. These results suggest that the …

Synthesis And Applications Of Mutimodal Hybrid Albumin Nanoparticles For Chemotherapeutic Drug Delivery And Phototherml Therapy Platforms, Donna V. Peralta

LSU New Orleans Theses and Dissertations

Progress has been made in using human serum albumin nanoparticles (HSAPs) as carrier systems for targeted treatment of cancer. Human serum albumin (HSA), the most abundant human blood protein, can form HSAPs via a desolvation and crosslinking method, with the size of the HSAPs having crucial importance for drug loading and in vivo performance. Gold nanoparticles have also gained medicinal attention due to their ability to absorb near-infrared (NIR) light. These relatively non-toxic particles offer combinational therapy via imaging and photothermal therapy (PPTT) capabilities.

A desolvation and crosslinking approach was employed to encapsulate gold nanoparticles (AuNPs), hollow gold nanoshells (AuNSs), …

Mechanisms And Transients Involved In The Solar Conversion Of Petroleum Films In Aquatic Systems, Phoebe Z. Ray

LSU New Orleans Theses and Dissertations

The behavior of Deepwater Horizon crude oil and other sources of oil were investigated when exposed to sunlight in aquatic systems under environmentally relevant conditions. This research decoupled the abiotic and biotic weathering modifications of oil by focusing solely on the photochemical transformations of oil in aquatic systems. Photochemical rates and mechanisms were measured through the determination of reactive transients. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. Titanium dioxide (TiO₂) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. Photochemical production …

Synthesis, Characterization And Optical Properties Of Conjugated Boronate-Linked Materials And Their Applications In Optical Sensing Of Lewis Bases, Min Cai

Theses and Dissertations

Organoboron compounds, with Lewis acidic boron centers, have been emerged as an important class of materials, especially in the area of chemical sensors. Herein, boranes and boronate esters in the sensing perspective were overviewed in Chapter 1. Examples of synthesis and sensing applications of boron-containing conjugated polymers were highlighted.

Boronate ester formation provides the advantages of facile synthesis, tunable optical properties, enhanced stability and planar geometry. Thus, boronate esters, especially dioxaboroles, were proposed to use as alternatives of boranes to design better sensors for Lewis bases. Based on the previous investigation of fluorenyl bis- and poly- dioxaboroles by our group, …

Biopolymeric Hydrogels Functionalized With Tobacco Mosaic Virus For In Vitro Three Dimensional Culture And Differentiation Of Stem Cells And In Vivo Tissue Regeneration, Jittima Amie Luckanagul

Theses and Dissertations

Plant viruses have been highlighted among material research due to their well-defined structures in nanoscale, mono-dispersity, stability, and chemical functionalities. Each of the thousands coated protein subunits on a viral nanoparticle can be homogenously modified, chemically, and genetically with a functional ligand leading to a high-density and spatial distribution of ligands on each particle (multivalency). Many reports from our group have clearly shown that virus coated substrates induced the acceleration of bone marrow stromal cells differentiation into bone cells. We hypothesized that this phenomenon could rely on the multivalency that the viral nanoparticle has to offer. Moving to a more …

Mechanistic Investigation Of A Silylation-Based Kinetic Resolution Using Linear Free Energy Relationships And Its Application To Substrate Expansion And Polymer Supported Kinetic Resolutions, Ravish K. Akhani

Theses and Dissertations

This dissertation represents our preliminary mechanistic investigations on the silylation-based kinetic resolution of secondary alcohols, and how we use that knowledge for further expansion of this methodology. Chapter 2 describes how we came up with a preliminary mechanism of our silylation-based methodology using a linear free energy relationship and a rate study. In this chapter, several para substituted triphenylsilyl chlorides were prepared that varied electronically and sterically in order to understand the substituent effects on the rate and the selectivity of the reaction. Selectivity factors and initial rates were experimentally determined for the kinetic resolution reactions with the newly designed …

Polyol Induced Extraction (Pie) Of Water From Organic Solvents, Mithilesh Deshpande

Seton Hall University Dissertations and Theses (ETDs)

Acetonitrile (ACN) is used in huge quantities for Reversed Phase High Performance Liquid Chromatography (RP-HPLC) experiments. For most of the part, these results in waste that is only contaminated with large amounts of water, buffer and trace organic impurities. It would seem worthwhile to purify the ACN from water using a mass separating agent (MSA). In a quest for an MSA, our investigation reveals polyols as a new class of MSAs. It is observed that when a polyol such as glycerol, sorbitol, erythritol, xylitol, Isomalt® or maltitol is added to a mixture of ACN-water, the ACN separates out of the …

Carboxylate Selective Lanthanide Imprinted Polymer Sensors For Sensor Array, Yang Xu

Theses and Dissertations

A europium-based molecularly imprinted polymer (MIP) was developed and characterized, which combined the highly luminescent properties of europium and the recognition properties of molecularly imprinted polymers. The europium-based MIPs were used as selective sensors for different types of carboxylates. The ultimate goal of this work was to develop a europium-based sensor array to differentiate carboxylates anions. The polymer was synthesized by using a europium–salen complex as the monomer and ethylene glycol dimethacrylate (EGDMA) as the crosslinker. First, a europium containing non-imprinted polymer (NIP) and a series of europium containing MIPs imprinted with acetate, benzoate and phenylacetate were synthesized by free …

Insights Into The Evolutional Adaptations And Functional Switching Mechanism In Dual Function Hemoglobin/Dehaloperoxidase (Dhp) And Modeling Of Cytochrome P450 Active Site With H93g Myoglobin Cavity Mutant, Shengfang Sun

Theses and Dissertations

The coelomic hemoglobin, dehaloperoxidase (DHP), from the sea worm Amphitrite ornata, is a dual function oxygen-binding heme protein that also possesses a significant peroxidase activity. As evolved from an ancient oxygen carrier globin, several structural adaptations have enabled DHP to evolutionally gain significantly enhanced peroxidase capability for self-protection while only minimally compromising its primary function as an O2 carrier. To elucidate these adaptations, the peroxidase activities and O2 affinities of several DHP and sperm whale myoglobin (Mb) mutants have been prepared. Several heme environmental structural factors that regulate the dual functions of DHP have been found, providing insight into how …

Extending The Limits Of Solid Phase Microextraction, Shilpi Chopra

Seton Hall University Dissertations and Theses (ETDs)

Solid phase microextraction (SPME) is a solventless extraction technique that combines sample preparation and sample introduction into a gas chromatograph into a single step. For the past 20 years, solid-phase micro-extraction (SPME) has been used in numerous fields such as: food analysis, including juices, alcohols fruits and vegetables for volatiles, aroma, caffeine, fatty esters, environmental applications including volatile organic contaminants, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phenols, pesticides, steroids, herbicides, acid/neutral/base compounds, and organometallic compounds from water, air, soil, sludge, and sediment samples and in biomedical analysis.

This work demonstrates the extension of the limitations of SPME with respect to extraction …

New Methods And Strategies For Orthogonal Oligosaccharide Synthesis, Scott James Hasty

Dissertations

Although scientists have been able to isolate certain classes of naturally occurring carbohydrates, the overall availability of pure natural isolates remains inadequate. As a result, chemical synthesis has been employed to access complex carbohydrates. Unfortunately, traditional oligosaccharide synthesis often requires laborious protecting-group manipulations that results in lower yields. Expeditious strategies effectively shorten the task of oligosaccharide assembly by minimizing the need for protecting-group manipulations between glycosylation steps, or even purification of the intermediates. Additionally, prediction of the stereoselective outcome of the coupling reaction between two sugar units is a major obstacle facing carbohydrate chemists. It is well known that 1,2-trans …

Surgical Adhesive From Mussel Mimetic Polymer, Jenna Desousa, Cori Jenkins, Jonathan Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Injuries involving damaged tissues are currently repaired through an invasive technique involving the use of screws, plates and sutures as support, which can damage these tissues. The biomedical field currently lacks an adhesive that can replace harmful implants. A surgical adhesive can provide a quick and easy alternative, which will minimize the risk of damaging healthy tissue in surgery. Inspiration for such materials can be found by looking at marine mussels as they are able to stick to nearly any surface, even in wet environments. Marine mussels affix themselves to different surfaces using adhesive plaques consisting of various proteins. Polymer …

High Level Protein Expression Slows Down Rate Of Growth Of Bacterial Broth Cultures, Saad Chaudhry, Kenechukwu Ekwemalor, Shobhit Keswani, Odutayo Odunuge

Undergraduate Research Conference

No abstract provided.

Determination Of Anions In Lanana Creek By Ion Chromatography, Tania Benavides

Undergraduate Research Conference

Abstract

Lanana Creek is one of two springs that surround Nacogdoches, TX. Lanana Creek starts southwest of Lake Naconiche, conjoining with several other bodies of water along its path, and becomes part of the Angelina River. This body of water eventually ends in the Gulf of Mexico which may contribute to the dead zone. Contaminants in water may be of small concentration; however, prolonged exposure could produce many negative effects. To prevent further contamination, the source of the contamination must be identified through testing the water for contaminants. Some possible sources of contamination may be from fertilizers and pesticides used …

Determining Force Field Parameters Involved With Metal Organic Framework Synthesis, Marcus A. Tubbs, David Cantu, Vanda Glezakou

STAR Program Research Presentations

Metal organic frameworks (MOFs) are synthetic materials made of a cage-like lattice with consistently spaced pores. The size of these pores are the defining characteristic of a MOF, as it determines which gases are allowed to pass through and which can be trapped. Examples of their potential use can be greenhouse gas sequestration or storage. Currently, the synthesis of MOFs is based on trial-and-error, and the successes are not well understood. We are working on building the theoretical framework that describes how a particular MOF, MIL-101, comes together during synthesis. Our initial approach was to simulate the possible reactions with …

Antimicrobial Nanoparticles: A Green And Novel Approach For Enhancing Bactericidal Efficacy Of Commercial Antibiotics, Monic Shah

Masters Theses & Specialist Projects

On the verge of entering the post-antibiotic era, numerous efforts are in place to regain the waning charm of antibiotics which are proving ineffective against most “Superbugs”. Engineered nanomaterials, especially gold nanoparticles (GNPs) capped with antibacterial agents, are proving to be an effective and novel strategy against multidrug resistant (MDR) bacteria. In this study, we report a one-step synthesis of antibioticcapped GNPs (25 ± 5 nm) utilizing the combined reducing and capping ability of a cephalosporin antibiotic, ceftazidime. No signs of aggregation or leaching of ceftazidime from GNP surface was observed upon its storage. Antibacterial testing showed dosedependent broad spectrum …

Green Synthesis And Evaluation Of Catalytic Activity Of Sugar Capped Gold Nanoparticles, Yogesh A. Kherde

Masters Theses & Specialist Projects

Owing to the importance of gold nanoparticles in catalysis, designing of them has become a major focus of the researchers. Most of the current methods available for the synthesis of gold nanoaprticles (GNPs) suffer from the challenges of polydispersity, stability and use of toxic and harmful chemicals. To overcome these limitations of conventional methods, in our present study, we made an attempt to design a method for the green synthesis of monodispersed and stable gold nanoparticles by sugars which act as reducing and stabilizing agent. Characterization of synthesized nanoparticles was done by using various analytical techniques such as transmission electron …

Selective Oxidations By Iron(Iii) Porphyrins And Iron(Iii) Corroles, Aaron Dalnamath Carver

Masters Theses & Specialist Projects

The selective oxidation of organic compounds represents a leading technology for chemical industries. They are used in chemical synthesis in the pharmaceutical and petrochemicals industries, and possible the decontamination of harmful substances. However, oxidations reaction are among the most challenging processes to control. Many stoichiometric oxidants with heavy metals are expensive, or toxic maybe both, and therefore unfeasible to be utilized. The ideal processes for catalytic oxidation would use molecular oxygen or hydrogen peroxide as the primary oxygen source, with transition metal catalysts to mimic the predominant oxidation catalysts in Nature, the cytochrome P450 enzymes. This study focuses on the …

Electron Paramagnetic Resonance Imaging And Probes, Hanan B. Elajaili

Electronic Theses and Dissertations

EPR imaging at low frequency is an important method to measure in vivo physiology. Because native paramagnetic species exist at low concentrations in living systems, exogenous paramagnetic species are needed for in vivo EPR. Selection of the appropriate EPR probe allows the experimenter to obtain information about the environment of the imaged probe and its spatial distribution. Relaxation times for several nitroxide radicals were studied with the aim of understanding the relaxation mechanisms, which provides criteria for design of suitable in vivo imaging probes.

Amino-substituted trityl radicals have the potential to monitor pH in vivo, and the suitability for this …

Theoretical/Experimental Comparison Of Deep Tunneling Decay Of Quasi-Bound H(D)Oco To H(D) + Co₂, Albert F. Wagner, Richard Dawes, Robert Continetti, Hua Guo

Chemistry Faculty Research & Creative Works

The measured H(D)OCO survival fractions of the photoelectron-photofragment coincidence experiments by the Continetti group are qualitatively reproduced by tunneling calculations to H(D) + CO₂ on several recent ab initio potential energy surfaces for the HOCO system. the tunneling calculations involve effective one-dimensional barriers based on steepest descent paths computed on each potential energy surface. the resulting tunneling probabilities are converted into H(D)OCO survival fractions using a model developed by the Continetti group in which every oscillation of the H(D)-OCO stretch provides an opportunity to tunnel. Four different potential energy surfaces are examined with the best qualitative agreement with experiment …

A Novel Dual Allosteric Activation Mechanism Of Escherichia Coli Adp-Glucose Pyrophosphorylase: The Role Of Pyruvate, Matías D. Asención Diez, Mabel C. Aleanzi, Alberto A. Iglesias, Miguel Ballicora

Chemistry: Faculty Publications and Other Works

Fructose-1,6-bisphosphate activates ADP-glucose pyrophosphorylase and the synthesis of glycogen in Escherichia coli. Here, we show that although pyruvate is a weak activator by itself, it synergically enhances the fructose-1,6-bisphosphate activation. They increase the enzyme affinity for each other, and the combination increases Vmax, substrate apparent affinity, and decreases AMP inhibition. Our results indicate that there are two distinct interacting allosteric sites for activation. Hence, pyruvate modulates E. coli glycogen metabolism by orchestrating a functional network of allosteric regulators. We postulate that this novel dual activator mechanism increases the evolvability of ADP-glucose pyrophosphorylase and its related metabolic control.

Testing Predicted Specificity Determinants In The Dihydrofolate Reductase Enzyme Family, Seema J. Patel

Theses, Dissertations and Culminating Projects

Dihydrofolate Reductase (DHFR) is an essential enzyme for most organisms, ranging from bacteria to humans. DHFR has essential functions in DNA biosynthesis and cell replication; as a result, cell growth can be inhibited by the inhibition of DHFR. Evaluating the use of well-known DHFR inhibitors is becoming essential in treating infections in the developing world as DHFR is a known target of antibacterial and antiparasitic drugs. Understanding determinants of DHFR inhibitor specificity in terms of amino acid sequence and structure will allow repurposing or designing of new compounds that selectively target DHFR from the pathogenic organism of interest over the …

Modified-Electrodes For Redox-Magnetohydrodynamic (Mhd) Pumping For Microfluidic Applications, Christena Kayl Nash

Graduate Theses and Dissertations

A new microfluidic pumping and stirring technique was demonstrated for lab-on-a-chip applications. Microfluidics was accomplished via redox-MHD, which takes advantage of a body force (F_B) that is generated when there is a net movement of ions in solution (j) in the presence of a perpendicular magnetic field (B), according to the equation F_B = j×B. In this work the movement of ions in solution was generated using electrodes modified with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) rather than a redox species in solution, which can interfere with analyte detection and with biological species. …

Communication: Rigorous Quantum Dynamics Of O + O₂ Exchange Reactions On An Ab Initio Potential Energy Surface Substantiate The Negative Temperature Dependence Of Rate Coefficients, Yaqin Li, Zhigang Sun, Bin Jiang, Daiqian Xie, Richard Dawes, Hua Guo

Chemistry Faculty Research & Creative Works

The kinetics and dynamics of several O + O₂ isotope exchange reactions have been investigated on a recently determined accurate global O₃ potential energy surface using a time-dependent wave packet method. The agreement between calculated and measured rate coefficients is significantly improved over previous work. More importantly, the experimentally observed negative temperature dependence of the rate coefficients is for the first time rigorously reproduced theoretically. This negative temperature dependence can be attributed to the absence in the new potential energy surface of a submerged "reef" structure, which was present in all previous potential energy surfaces. In addition, contributions …

Synthesis And Characterization Of Novel Platinum(Ii) And Platinum(Iv) Complexes Containing 4,4′--Disubstituted--2,2′--Bipyridine Ligands For The Treatment Of Cancer, Van Vo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Three series of platinum(II) and platinum(IV) complexes containing 4,4′-disubstituted-2,2′-bipyridine ligands have been synthesized and characterized by 1H NMR, 13C NMR spectroscopy, elemental analysis, mass spectroscopy, and differential scanning calorimetry measurements. The MTS cell proliferation assay was used to examine the in vitro anti-proliferative activities of these complexes in various human breast, lung, and prostate cancer cells. The cell's response to the complexes varies between different cell lines; however, the low EC₅₀ values determined from the MTS data indicate that several of the complexes are much more potent than cisplatin.

Flow cytometric analysis of selected compounds revealed induction of apoptosis …

The Nucleic Acid Binding Properties Of The Pwi Motif, Hamideh Keshavarz-Mohammadian

Masters Theses

The PWI motif is a highly conserved domain that contains a Proline-Tryptophan-Isoleucine (PWI) tripeptide sequence, for which it is named. Proteins that contain a PWI motif are known to be involved in the constitutive and alternative splicing and the 3'-end processing of messenger RNA transcripts. The hypothesized role of the PWI motif is to nonspecifically interact with nucleic acids. The PWI motif is capable of binding both doublestranded and single stranded forms of DNA and RNA. The structure of the highly conserved core of the PWI motif reveals that it adopts a four-helix bundle fold. The structured core domain, however, …

Electron Transfer In Pnicogen Bond, Liangyu Guan

Masters Theses

Abstract is available for download as a separate file.

Synthesis Of 4'-Ester Resveratrol Analogues, Chromium Trioxide Oxidation Of Terpenes, And Synthesis Of Mimics Of (-)-Englerin A, Mark Jeffrey Acerson

Theses and Dissertations

4’ -ester analogues of resveratrol were synthesized using reaction conditions developed to produce mono-ester products in the presence of two other unprotected phenols. Basic conditions were employed to deprotonate the most acidic 4’ phenol followed by addition of anhydrides or acid chlorides to give the ester product. The reaction favored 4’-ester formation in polar aprotic solvents with DMSO being the optimal solvent.

(—)-Englerin A is a guaiane-type sesquiterpene containing two ester side chains. Mimics of (—)-englerin A were proposed that retained the ester side chains while replacing the non-polar core with less complicated structures. These proposed mimic cores would maintain …

Persistent Hepatic Structural Alterations Following Nanoceria Vascular Infusion In The Rat, Michael T. Tseng, Qiang Fu, Khoua Lor, G. Rafael Fernandez-Botran, Zhong-Bin Deng, Uschi M. Graham, D. Allan Butterfield, Eric A. Grulke, Robert A. Yokel

Chemistry Faculty Publications

Understanding the long-term effects and possible toxicity of nanoceria, a widely utilized commercial metal oxide, is of particular importance as it is poised for development as a therapeutic agent based on its autocatalytic redox behavior. We show here evidence of acute and subacute adverse hepatic responses, after a single infusion of an aqueous dispersion of 85 mg/kg, 30 nm nanoceria into Sprague Dawley rats. Light and electron microscopic evidence of avid uptake of nanoceria by Kupffer cells was detected as early as 1 hr after infusion. Biopersistent nanoceria stimulated cluster of differentiation 3⁺ lymphocyte proliferation that intermingled with nanoceria-containing …

Chitosan-Cellulose Composite For Wound Dressing Material. Part 2. Antimicrobial Activity, Blood Absorption Ability, And Biocompatibility, April L. Harkins, Simon Duri, Luther C. Kloth, Chieu D. Tran

Clinical Lab Sciences Faculty Research and Publications

Chitosan (CS), a polysaccharide derived from chitin, the second most abundant polysaccharide, is widely used in the medical world because of its natural and nontoxic properties and its innate ability for antibacterial and hemostasis effects. In this study, the novel composites containing CS and cellulose (CEL) (i.e., [CEL + CS]), which we have previously synthesized using a green and totally recyclable method, were investigated for their antimicrobial activity, absorption of anticoagulated whole blood, anti-inflammatory activity through the reduction of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and the biocompatibility with human fibroblasts. The [CEL + CS] composites were found to …