Physical Sciences and Mathematics Commons^™

Hydrophobically Modified Isosorbide Dimethacrylates As Biomaterials For Bisphenol A Free Dental Fillings, Bilal Marie

Dissertations

Amalgam and Bisphenol A glycerolate dimethacrylate (BisGMA) are the main dental filling materials in use today. Because of the negative perception of amalgam and its lower esthetic appeal, as well as the desire to replace the endocrine disruptor Bisphenol A, which is the building block of BisGMA, there has been a critical need to search for safer alternatives to these dental filling materials.

Isosorbide is a sugar-based molecule generally recognized as safe. It has been extensively studied as a replacement to the Bisphenol A core in various materials. However, isosorbide is extremely hygroscopic, and water uptake in dental fillings causes …

Characterization Of The Ch Addition Product From Meta- And Ortho-Xylene + Ch Reaction And Direct Experimental Observation Of The Tetrabromine Cluster Br4 Using Synchrotron Photoionization Mass Spectrometry, Rory R. Mcclish

Master's Theses

This thesis is centered on the use of a unique gas-phase spectroscopy technique to characterize products and elucidate reaction mechanisms. Experiments were carried out at the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source located at the Lawrence Berkeley National Laboratory in Berkeley, CA. Computational work was performed on the scientific supercomputer at USF to supplement experimental findings. Chapter 1 contextualizes the work spurred in response to the deleterious interactions of anthropogenic emissions on Earth’s climate. Chapter 2 describes the theoretical manipulations foundational to the experimental design and interpretation. Chapter 3 delves into the physical details of the experimental …

Exploration Of Carbon-Oxygen And Carbon-Nitrogen Bond Formation Utilizing Trichloroacetimidates And Investigations Of New Reactions Mediated By Oxoammonium Salts, Rowan Meador

Dissertations - ALL

Mono-O-alkylated 1,1′-bi-2-naphthols (BINOLs) are often used as the source of chirality for catalysts or ligand systems that are employed in asymmetric organic transformations. However, these BINOLs can be hard to synthesize. The O-alkylation of BINOL can be accomplished with primary and secondary alkyl halides or under Mitsunobu conditions, the yields of these alkylations with tertiary halides or alcohols are very low. A new protocol was developed utilizing trichloroacetamide electrophiles to install bulky groups onto one of the phenolic oxygens. Trichloroacetimidates are also shown to be useful reactions for the synthesis of esters. These reagents proceeded through a symbiotic activation pathway. …

The Phase Behavior Of Ubqln Proteins And Implications For Protein Quality Control, Yiran Yang

Dissertations - ALL

The ubiquitin-proteasome system (UPS) and autophagy are essential pathways for maintaining protein quality control (PQC) in cells. Misfolded proteins and large aggregates are cleared by UPS and autophagy signaled by ubiquitin (Ub) or polyubiquitin (polyUb) chains. Shuttle proteins facilitate cargo transporting by interacting with both ubiquitin and degradation machineries. Previously, our lab discovered that the shuttle protein Ubiquilin-2 (UBQLN2) is recruited to stress granules in cells and undergoes liquid-liquid phase separation (LLPS) in vitro. LLPS is a biophysical process by which proteins separate themselves from the surrounding aqueous solution by forming protein-rich droplets. The overarching goals of this work are …

The Immobilization Of Ticagrelor On Implant Materials And Corrosion And Biofouling Inhibition By Novel Layered Polymer Thin Films For Marine Application, Tell Lovelace

Electronic Theses and Dissertations

Percutaneous coronary interventions are a widely used cardiovascular surgery which is typically accompanied by the insertion of a vascular stent. After the procedure patients are put on dual anti-platelet therapy (DAPT) to prevent stent thrombosis, a common complication to this procedure in which platelets aggregate in the blood vessel on the inserted stent. Systemic deactivation of platelets in patients via oral DAPT results in patients becoming bleeding risks in future medical procedures, necessitating the development of a localized delivery system for anti-platelet medications from the surface of the stent. A novel anti-thrombogenic vascular stent coating has been prepared by covalent …

Functional Structure Of Biomacromolecules In Plant Biomass Using Solid-State Nmr And Dynamic Nuclear Polarization, Alex Kipchirchir Kirui

LSU Doctoral Dissertations

This dissertation summarizes the recent findings on complex biomacromolecules in cell wall of plants and fungi which perform important roles in cell recognition, structural build up, and energy storage. Because of the technical difficulty in characterizing these biomacromolecules, which are often polymorphic and disordered in structure, the functional structure of these biomacromolecules remains elusive. In this dissertation, I present two solid-state nuclear magnetic resonance (ssNMR) and dynamic nuclear polarization (DNP) studies of carbohydrate-rich biosystems: the energy-rich plant biomass and disease-relevant, pathogenic fungi.

First, we have investigated the secondary cell wall of plant biomass which is a carbohydrate-rich biosystem using solid …

The Effects Of Solution Ph, Temperature And Redox Environment On Corrosion And Oxide Formation On Inconel X-750, Mohsen Bahrami

Electronic Thesis and Dissertation Repository

Nickel-based superalloys have a wide range of applications in different industries due to their exceptional mechanical and corrosion-resistance properties. These alloys are widely employed in the nuclear industry. Inside a nuclear reactor, these alloys are exposed to a continuous flux of gamma-radiation. When exposed to gamma-radiation, water decomposes, resulting in the production of oxidizing and reducing species. These species have a considerable effect on the redox chemistry of the solution, which controls the overall corrosion behaviour of nickel-based superalloys.

Corrosion of metals and alloys involves several elementary steps. A comprehensive understanding of these steps and how they influence each other …

Design And Synthesis Of Small Molecular Probes For Cns And Kidney Disorders, Swagat H. Sharma

Theses & Dissertations

The G protein regulated inwardly rectifying potassium channels (GIRK) are a family of inwardly rectifying potassium channels and are key effectors in signaling pathways. GIRK 1/2 channel subunit, predominantly found in the brain, is involved pathophysiology of various neurological disorders including, but not limited to, epilepsy, anxiety, Parkinson's, pain, reward, and addiction. Previously, our laboratory had identified a series of urea containing molecules as GIRK1/2 preferring activators. Unfortunately, the urea series suffers from significant PK liabilities (solubility, brain penetration and high clearance). The chapter 1 of the dissertation describes our efforts in developing three new series of activators with improved …

Selective Oxidation Of Alkenes In Air Catalyzed By Mn3o4 Nanoparticles, Brojo Kishor Shachib Dhali

Dissertations and Theses

Catalytic oxidation is a process where compounds are oxidized using catalysts. Solid catalysts exhibit several advantages over homogeneous systems, such as catalyst recovery and excellent stability. Various supported transition-metal oxides (for example: CuO, ZnO, CeO2, Fe2O3 and WO3), metal nanoparticles (for example: Pd and Ru) and polyoxometalate clusters (for example: [W10O32]4-, [Mn2ZnW(ZnW9O34)2]10- and [XW12O40]n- (X = P, Si)) have been applied to selective oxidation of organic compounds, but high associated product conversion still remains a challenge. Recently, a number of materials containing Mn3O4 have been used successfully in different catalytic applications, such as degradation of phenols, reduction of nitrobenzenes, and …

Electrodeless Electrochemistry Enabled By Nonthermal Plasma, Harold Oldham

McKelvey School of Engineering Theses & Dissertations

The increasing availability and decreasing cost of electricity generated by renewable resources have motivated research into electrified chemical processing, whereby electrical energy is used to drive chemical transformations. Electricity-intensive processing techniques such as electrochemistry using solid electrodes has attracted attention in this context for the synthesis of organic compounds, such as high-value pharmaceuticals and renewable chemical production. Selective chemical transformations are achieved in conventional aqueous electrochemical systems by using external circuitry to bias solid electrodes, allowing for the preferential transfer of electrons between the electrode-liquid interface. Despite having the ability to promote controlled electrochemical reactions, configurations using solid electrodes are …

Electro-Organic Chemistry: An Alternative Pathway To Handle Redox Organic Reactions, Tiandi Wu

Arts & Sciences Electronic Theses and Dissertations

Electrochemistry provides an alternative pathway to handle redox organic reactions, especially for certain chemical process that can be only achieved through electrochemical process. Herein, there research projects are introduced to enrich the whole synthetic community, including an anodic oxidative cyclization studies to develop methodology on heterocyclic ring skeleton constructions, an electroreduction pathway exploration to more effectively obtain hydrazine from nitroso compounds, as well as a study in paired electrolysis process on which both anode and cathode are simultaneously employed to maximize overall atom and energy efficiency. Future directions on these projects are also demonstrated at the end of each chapters..

Mass Spectrometry-Based Protein Footprinting: High-Throughput Maldi Platform And Large Protein Complexes Of Baf, Ruidong Jiang

Arts & Sciences Electronic Theses and Dissertations

Human’s advances in understanding biological processes rely heavily on the breakthroughs in biophysical tools. Mass spectrometry (MS)-based protein footprinting, which interrogates protein structures by measuring protein solvent assessable surface area (SASA), has grown rapidly in the last decade, successful in providing valuable data for numerous protein systems. This thesis focuses mainly on this technology.We set out to push the boundary of MS-based protein footprinting further into the new areas, preparing it for potential future applications including large-scale experiments that require high-throughput analysis the structure of large, complicated protein complexes. This thesis devotes five chapters to the method development of MS-based …

Interfacial Engineering And Photoelectrochemistry Of Patterned Metal/Semiconductor Heterostructures, Che Tan

McKelvey School of Engineering Theses & Dissertations

Photoelectrochemical (PEC) cells enable the conversion of solar energy into storable fuels, which is critical in overcoming the intermittent nature of this largest renewable source. However, the majority of semiconductors used as photoelectrodes in these cells have low conversion efficiencies and/or stabilities. Silicon (Si) is an attractive semiconductor material for photoelectrodes, but the development of efficient Si-based photoanodes is challenging due to their instability in alkaline solutions. Thus, one focus of this dissertation is the design and fabrication of highly stable nickel (Ni)-patterned Si photoanodes through interfacial engineering of the barrier heights. Recently, hot carriers in plasmonic metal nanostructures have …

Cyclodextrin-Based Supramolecular Drug-Delivery Nanomaterials And Shear-Thinning Hydrogels Using Ring-Opening Metathesis Polymerization, Ruihan Li

Arts & Sciences Electronic Theses and Dissertations

Cyclodextrins (CD) are a family of oligosaccharides that can non-covalently and precisely bind small hydrophobic drug molecules, such as antibiotics and anticancer drugs, through well-defined host-guest interactions inside the inner cavity of the macrocycle. Ring-opening metathesis polymerization (ROMP) is a versatile, functional group tolerant method of polymerization that is underexplored in biomedical applications relative to the more common controlled chain-growth polymerizations. In this dissertation, I describe my efforts to combine the supramolecular chemistry of CDs with that of ROMP using specialized functional monomers to synthesize several CD-based polymeric drug delivery nanomaterials. For example, in Chapter 2, a new type of …

Using Single-Particle Fluorescence Microscopy To Elucidate The Role Of Structural Distortions And Defects In The Chemical Reactivity And Photophysics Of Cesium Lead Halide Perovskite Nanocrystals, Dong Wang

Arts & Sciences Electronic Theses and Dissertations

Colloidal cesium lead halide perovskite nanocrystals (CsPbX3, X = Cl, Br or I) are attractive for optoelectronic applications due to their unique chemical and physical properties including high photoluminescence quantum yield, tunable bandgaps, high defect tolerance, and low-cost processibility. A facile method to tune the emission wavelength of perovskite nanocrystals is through anion exchange. For light emission applications, it is desirable to prepare CsPbX3 nanocrystals of uniform size and composition. However, the complex reaction kinetics of this chemical transformation may limit the compositional uniformity and color purity of the CsPbX3 nanocrystals produced by anion exchange when the transformation is scaled …

Antimicrobial Activity Of Bacterial Virus Components: An Empirical Investigation Of The Killing Capacity Of Toxins From Burkholderia, Kyle Walny

Honors Projects

Given the growing issue in healthcare of antibiotic resistance, effective and safe alternative treatment methods are required. One of these possible alternative treatment methods is bacteriotoxins including bacteriocins and tailocins. The focus of this study is a bacteriotoxin from Burkholderia cenocepacia (ATCC 25608), which was induced for toxin using a modified UV light induction procedure and tested against a variety of Pseudomonas and Burkholderia for its killing capacity. Various other pathogenic strains were then induced with UV light and tested. The results showed that the toxin from ATCC 25608 was very effective against most of the Burkholderia tested and warrants …

Seasonal Flammability Comparisons Of Native And Exotic Plants In The Post Oak Savannah, Blackland Prairie, And Pineywoods Ecoregions Of Texas, Michael Tiller

Electronic Theses and Dissertations

East Texas’ diverse landscape can present year-round wildfire seasons that can be influenced by seasonal and regional differences in climate and physiography. Greater insight into the fundamental thermal behavior of wildland fuels can aid in fire behavior prediction and development of fire-resistant plant lists. This study focused on estimating seasonal and regional flammability characteristics of five evergreen species: yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), greenbrier (Smilax spp.), eastern red cedar (Juniperus virginiana), and escarpment live oak (Quercus fusiformis); and two deciduous species: Chinese tallow (Triadica sebifera) and southern …

1,2-Diazetidine As A New Amidomethylative Reagent To Control The Selectivity For The Synthesis Of N-Heterocycles And Ru(Ii)-Catalyzed Enantioselective Hydroarylation To Form Chromane Derivatives, Chaminda Lakmal Hetti Handi

Theses and Dissertations

1,2-Diazetidine is a four-membered ring heterocyclic compound which has two adjacent nitrogen atoms. However, the syntheses of C-unsubstituted 1,2-diazetidines are rarely reported in the literature. C-unsubstituted 1,2-diazetidines were synthesized through an operationally simple intermolecular vicinal disubstitution reaction between 1,2-dibromoethane and hydrazine with N-arylsulfonyl as the protecting group. Several different types of C-unsubstituted 1,2-diazetidines derivatives were synthesized with either two of the same or two different N-arylsulfonyl groups. The electronic and steric properties were analyzed using Raman spectroscopy and computational calculations. Then, several synthetic applications were demonstrated with 1,2-ditosyl-1,2-diazetidine (DTD). As a synthetic application, a nucleophilic ring-opening reaction of the diazetidine …

Synthesis And Characterization Of A Ccc-Nhc Manganese Complex And Its Catalytic Activity In Alpha-Alkylation Reactions Of Ketones Using Alcohols – Acceptorless Dehydrogenative Coupling Reaction, Thi Bao Tran Nguyen

Theses and Dissertations

N-heterocyclic carbenes are essential for the synthesis and stabilization of various metal complexes due to the tendency to act as sigma-donor of sp2 hybridized lone pair in carbene into sigma-accepting orbital of metals. Meanwhile, the electronic and steric properties of pincer complexes can be fine-tuned by modifying three sites bonded to the metals. Utilizing advantages of both NHCs and the pincer structures, NHCs-based pincer complexes have become increasingly developed in recent years. After the discovery of zirconium and rhodium complexes with CCC-NHC backbones reported in 2005, Hollis’s group has been interested in applying the CCC-NHC pincer precursor for other transition …

Characterization Of Small Molecules And Ions By Atmospheric Pressure Ionization-Mass Spectrometry, Maleesha De Silva

Theses and Dissertations

Mass spectrometry (MS) has become a widely used technique for the characterization of a wide range of substances in diverse fields. The selection of appropriate ionization techniques, source parameters, charge carriers based on the analyte’s polarity is essential in MS as only the ions are detected. When using a soft ionization technique, single stage-MS at best provides only chemical composition; thus, tandem MS is needed to determine structural information and dissociation pathways. This dissertation focuses on the characterization of various small molecules and ions using different ionization techniques, charge carriers, and collision-induced dissociation (CID).

In Chapter II, commercially available ionic …

Corn Oil-Based Highly Flame Retardant Rigid Polyurethane Foams For Industrial Application, Muhammad Rizwan Sulaiman

Electronic Theses & Dissertations

The synthesis of flame retardant polyurethane (PU) foam was carried out using two different flame retardants, such as triethyl phosphate (TEP) and triphenyl phosphate (TPP). The thermal and mechanical characteristics of the foam were analyzed. The obtained TGA results confirmed that the flame retardant acts in the gaseous form to stop the fire. All the prepared samples displayed excellent closed cell content, which was above 90 %. The burning time were reduced from 80 s to 7.5 s with the weight loss 3.2% of for sample E-12 (19.29 % TEP) and from 80 s to 11 s with the weight …

Disease Biomarker Discovery And Fungal Metabolites Extraction Protocol Optimization Using Gcms Based Metabolomics, Chathuri Udeshika Gamlath Mohottige

Theses and Dissertations

Metabolomics is a powerful science that can be applied for the discovery of disease biomarkers, and investigation of altered metabolomes due to abiotic and biotic perturbations. This dissertation is focused on untargeted metabolomic applications to investigate fungal metabolite alterations associated with pathogenicity, fungal disease propagations, and symbiosis. This dissertation employs qualitative analysis of metabolite mixtures using HS-SPME coupled GC-MS and TMS derivatization followed by GC-MS analytical platforms. In the first study, we discovered a biomarker combination to diagnose fungal soft tissue disease in sweet potato at an early stage of disease propagation. We used an HS-SPME GC-MS untargeted metabolomics workflow …

A Computational Study On A Globular Protein And An Intrinsically Disordered Protein, Cecilia Chavez Garcia

Electronic Thesis and Dissertation Repository

We present molecular dynamics (MD) simulations of two protein targets for drug design: Triosephosphate isomerase (TIM) and Methyl CpG binding protein 2 (MeCP2). First, we studied three TIM proteins: TcTIM, TbTIM and a chimeric protein (Mut1). The first two are homologous enzymes with high sequence similarity, albeit different biophysical parameters. The chimeric protein has TbTIM’s sequence and 13 single point mutations, which are sufficient to obtain TcTIM-like behaviour in reactivation experiments. We analyzed the residue interaction networks observed in the all-atom MD simulations, as well as their electrostatic interactions and the impact of simulation length on them. A conserved salt …

Quantum Mechanics-Based Computational Chemistry Has Become A Powerful Partner In The Scientific Research Of Nitrogen-Rich Compounds, Paving The Way For Important Advances In Biochemical, Pharmacological And Other Related Fields, Dobrushe Denburg

Student Theses and Dissertations

The Computational Chemistry of Nitrogen-Rich Compounds; Insight into Pioneering Research

Nitrogen-rich functional groups have long been studied for their diversity; nitrogen can form single, double and triple bonds with itself, and will therefore exist in a very broad range of molecular arrangements. Poly-nitrogen compounds are highly energetic and electron rich, and many compounds display unique properties that allow participation in very specialized chemical reactions. Of import is their ubiquity in biological systems, and throughout the past century and currently, their biological relevance is deeply and widely explored in biochemistry and biomedicine, from their involvement in natural biological processes and complex …

In Situ Study Of Geological Fluid Inclusions Using 23na Nuclear Magnetic Resonance Spectroscopy, Stephen Pilar

Electronic Thesis and Dissertation Repository

²³Na Magic Angle Spinning Solid State Nuclear Magnetic Resonance (MAS SS NMR) spectroscopy has been used to study natural geological samples of halite, fluorite, and quartz to evaluate the efficacy of NMR spectroscopy for in situ fluid inclusion analysis. NaCl calibration standards yielded a strong linear correlation (R²=0.9919) for salinity, albeit only over a ~1 ppm breadth of chemical shift. Fluid inclusions were successfully identified in all three types of minerals studied using MAS NMR. Chemical analysis with Inductively Coupled Plasma -- Mass Spectrometry (ICP-MS) was employed to quantify elemental contaminants in halite samples. Powder X-Ray Diffraction …

Metal Ligand Cooperative Complexes For Acceptorless Dehydrogenation Of Amines, Matthew D. Hoffman

Electronic Thesis and Dissertation Repository

Complexes of the type [M(Cp/Cp*)(MeCN)(P^R₂N^R′₂)]PF₆ (M = Fe, Ru) were synthesized and/or tested towards acceptorless dehydrogenation (AD) of amines. The primary amine benzylamine can undergo AD to form a mixture of products, and a selection of catalysts were employed in an attempt to control product selectivity. As a result, trends in product distribution were observed by modifying the primary and secondary coordination spheres on the catalyst. A new complex, [Fe(Cp)(MeCN)(P^Ph₂N^Ph₂)]PF₆ (3a) was synthesized and characterized and was found to be a completely selective dehydrogenation …

Total Internal Reflection: Applications In Nonlinear Microscopy And Fluorescence Anisotropy, Brandon Colon

Doctoral Dissertations

As technology advances to harness new energies and to create new cures, the sophistication of analysis grows not only in depth but in efficiency. Total internal reflection (TIR) has been coupled to microscopy leveraging its unique optical phenomenon on a breadth of topics. In this dissertation, the work presented will show how TIR was applied in two different instrumental analyses to evaluate two unique and complex systems. The first project features TIR paired with the transient absorption microscopy (TAM), a nonlinear optical technique, to gauge solvent mixing and diffusion in microreactors. Microreactors gained acclaim for their ability to produce high …

Instrument Development For High Sensitivity Size Characterization Of Lipid Vesicles And Other Biological Macromolecules Via Taylor Dispersion Analysis, Meagan Moser

Doctoral Dissertations

Just as humans communicate with other humans, the cells in our bodies communicate with each other through various, often complex, mechanisms. Cell-to-cell transmission of small molecules, lipids, proteins, peptides, or nucleic acids can be mediated by extracellular lipid vesicles called exosomes. Exosomes have been found to play a role in the delivery of regulatory molecules from one cell to another, serving as a universal communication mechanism. Currently, there is an emerging focus on characterizing exosome communication dynamics. Understanding exosome mechanisms of cell-to-cell communication requires accurate measurements of the spatiotemporal and chemical dynamics of exosome secretion. No current analytical approach offers …

Application Of Single-Ion Conducting Polymer Electrolytes (Sicpes), Sheng Zhao

Doctoral Dissertations

Polymer electrolytes have been widely studied as a potential candidate for next generation batterie with improved safety and higher energy density. Especially, single-ion conducting polymer electrolytes (SICPEs) have attracted significant attention due to their almost unity lithium-ion transport number, which is believed to help suppress lithium dendrite growth and extend battery cycle life. However, there is still a long way to go before they can be practically applied in batteries, due to their relatively low ionic conductivity at ambient temperature. Therefore, the main goal of this work is to explore various methods that can improve the ionic conductivity of SICPEs …

Ultrasound-Driven Fabrication Of Nanosized High-Entropy Materials For Heterogeneous Catalysis, Francis Uchenna Okejiri

Doctoral Dissertations

High-entropy materials (HEMs) have emerged as a new class of multi-principal-element materials with great technological prospects. As a unique class of concentrated solid-solution materials, HEMs, formed on the premise of incorporating five or more principal elements into a single crystalline phase, provide an excellent opportunity to access superior catalytic materials ‘hiding’ in the unexplored central regions of a multicomponent phase space of higher orders.

However, the fabrication of HEMs is energy-intensive, typically requiring extreme temperatures and/or pressures under which agglomeration of particles occurs with a commensurate decrease in surface area. For most catalytic applications, non-agglomerated particles with high surface areas …