Chemistry Commons^™

Molecular Basis Of Xenobiotic Metabolism And Resistance In Tetranychus Urticae, Leily Daneshian

Theses and Dissertations

Invasive pest species are a major cause of crop loss around the world and adversely affect the agricultural industry. We are focusing on Tetranychus urticae (two-spotted spider mite; TSSM), which is a polyphagous pest that targets more than 1100 plant species. The TSSM alone causes a loss of roughly $1.6 billion per year globally due to acaricide resistance. It is developing resistance to most acaricides due to rapid growth and reproduction. Therefore, new acaricides are needed to combat TSSM resistance and infestation [1]. To address this problem, four enzymes of TSSM, intradiol ring cleavage dioxygenases, a glutathione S-transferase, a β …

Fate Of Persistent Contaminants And Emerging Algal Toxins In Drinking Water And The Environment, Danielle Christine Westerman

Theses and Dissertations

Population growth and global climate change has resulted in the degradation of pristine water sources, causing issues like saltwater intrusion, persistent harmful algal blooms, and drought from population growth. Future reliance on alternative sources of drinking water to is expected globally, therefore, nontraditional sources of drinking water are becoming increasingly vital sources of potable water around the world. For example, desalination (typically by reverse osmosis), despite its high energy demands and high cost, is being utilized all over the world to meet drinking water demand. Wastewater reuse, the additional treatment of wastewater to produce drinking water, either directly or indirectly, …

Studies Of The Chemistry Of Pentaruthenium Carbido Carbonyl Cluster Complexes With Aldehydes, Azobenzene And Alkynes, Humaiara Akter

Theses and Dissertations

Polynuclear metal carbonyl complexes serve as the bridging model between heterogeneous catalysis and homogeneous catalysis for the activation of small molecules. Ru5(m5-C)(CO)15 has been found to exhibit superior reactivity due to its unusual polynuclear metal geometry. possibilities of interconversions of ligand bonding modes, and the formation of the electronically unsaturated metal species. C-H activation in aldehydes and azobenzene of pentaruthenium cluster complexes is described in chapters 2 and 3 respectively. The formation of new hydrocarbyl zwitterions and C – C coupling ethyne to the carbido carbon in the complex, and the alkyne insertion reactions with pentaruthenium cluster complexes are described …

Cationic Metallo-Polyelectrolytes: Synthesis And Application In Self-Assembly And Mechanochemistry, Yujin Cha

Theses and Dissertations

In this dissertation, cationic metallocene-containing polyelectrolytes were investigated for the construction of nano-objects by CDSA and the mechanical force-responsive polymer. The self-assembly behavior and mechanically induced polymer deformation were characterized and discussed.

In Chapter 1, the overall background and recent development of metallocene-containing polymers as well as their applications in self-assembly and polymer mechanochemistry were introduced. Primary research objectives were described.

The first section of the dissertation on the CDSA of cationic metallocene-containing block copolymers was provided in Chapter 2. The preparation of PCL-b-PCoAEMAs was achieved through ring-opening polymerization (ROP) of ε-caprolactone and reversible addition-fragmentation chain-transfer (RAFT) polymerization of cobaltocenium …

Sparse Modeling For Predicting Class Assignments For Trace Forensic Evidence, Dayla Christine Rich

Theses and Dissertations

Numerous disciplines in forensic science utilize various types of spectral data when analyzing evidence. Spectral techniques are particularly critical for the analysis of trace evidence, as these methods are normally non-destructive. Preserving evidence, especially trace evidence, is of high priority in a forensic laboratory setting. Once a piece of evidence has been fully consumed, no more analyses can be performed. Typically, visual comparison, or spectral overlay, is performed to compare questioned samples (evidence) to standards or knowns. However, such an approach may not be optimal in distinguishing the subtle, yet highly important, discriminating characteristics present in the spectra. As statistical …

Characterization And Hydrogenation Activity Of Supported Palladium Particles, Narayan Acharya

Theses and Dissertations

In this project, the hydrogenation activity of palladium (Pd) particles supported on different carbon and oxide supports was investigated. Supported Pd particles were prepared using strong electrostatic adsorption (SEA) technique, which is known to produce metal particles with narrow and uniform distribution. The scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), and chemisorption methods were used to characterize the Pd particle size in this project. The Pd particles on different supports were annealed at a specific temperature, and the particle size was studied as a function of annealing temperature. Propylene hydrogenation to propane was conducted in a flow reactor to …

Functional Supramolecular Materials And The Design And Synthesis Of Triple Negative Breast Cancer Pharmaceuticals, Dustin Wayne Goodlett

Theses and Dissertations

Organization of benzophenone in the solid-state facilitates the formation of persistent and regenerable radicals at room temperature upon exposure to light. Upon incident irradiation, the triplet sensitizer rapidly undergoes intersystem crossing to a triplet excited state. Structural investigation of four distinct benzophenone supramolecular assemblies gives insight into the different processes these materials can undertake once in the triplet excited state such as persistent radical formation, phosphorescence, and self-quenching.

Self-assembly of brominated triphenyl amine bis-urea macrocycles forms a host material with unidirectional pores. Separations of xylene constitutional isomers via adsorption within this crystalline host material at ambient temperature are shown to …

Effect Of Oil And Gas Extraction On Disinfection By-Product Formation In Drinking Water, Dallas Graham Abraham

Theses and Dissertations

Certain industrial processes, such as energy extraction and utilization, generate massive amounts of wastewater with various geogenic and synthetic contaminants. Oil and gas wastewaters are characterized by elevated halide levels, particularly geogenic bromide and iodide. Concentrations in produced wastewaters have been reported as high as thousands of mg/L of bromide and tens of mg/L of iodide. Large volumes of these wastewaters are stored, transported, and disposed of, potentially impacting drinking water sources. Because conventional wastewater treatment fails to remove halides, oil and gas wastewater disposal, even after treatment, facilitates the formation of brominated and iodinated disinfection by-products (DBPs) at downstream …

Automating And Implementing Complex, Multistep Sample Preparation Processes To Generate Reproducible Proteomic And Phosphoproteomic Data, Brian Todd Mullis

Theses and Dissertations

Phosphorylation is the most common post-translational modification that occurs within the cell and is intricately involved in many biological processes. It is important to understand the roles that protein kinases and phosphatases play by mapping protein phosphorylation as many disease states stem from aberrant signaling events. With the advent of modern mass spectrometry (MS), researchers are now provided with more complex phosphorylation patterns from thousands of proteins in each mass spectrometric analysis. Further developments in quantification techniques, such as stable isotope labeling with amino acids in cell culture (SILAC) and label-free quantitation, have allowed researchers to reliably quantify changes to …

Molten Alkali Halide Salt-Flux Crystal Growth And Physical Property Determination Of Complex Oxides And Chalcogenides Supported By First Principles Density Functional Theory Calculations, Mohammad Usman

Theses and Dissertations

The primary objective of this dissertation is to inform the reader about more thansixty new materials with potentially attractive physical properties obtained via molten alkali halide flux methods as X-ray diffraction quality crystals. Flux crystal growth carries several advantages over other synthetic methods, including low reaction temperatures and straightforward post-reaction workup. This dissertation consists of 11 chapters, including an introductory chapter, which are organized into two parts, each corresponding to the general structure type of the family of oxides and chalcogenides being investigated. Part 1, which encompasses chapters 2–6, is dedicated to the discussion of crystal growth of complex chalcogenides …

Improving Sers Detection Of Illicit Drugs Using A Plasmonic Substrate Modified With Self-Assembled Monolayers, John Harms

Theses and Dissertations

Due to the worsening national drug epidemic and increasing prevalence of exceptionally potent synthetic opioids, there is a need to improve the forensic detection of illicit drugs, including sample analyses conducted on-site. In this thesis, the analysis of several illicit drugs spotted onto plasmonic surfaces was investigated using surface-enhanced Raman spectroscopy (SERS) with the goal of improving detection limits. Plasmonic surfaces (gold nanoparticle-loaded filter papers) were prepared and characterized prior to their SERS applications. Plasmonic surfaces were then further modified for improved SERS detection of each illicit drug with the treatment of self-assembled monolayer (SAM) forming compounds; in addition to …

Synthesis Of Oxyquinoliziniporphyrins And Pyridoquinoliziniporphyrins, Emma Cramer

Theses and Dissertations

N-confused porphyrins are porphyrin analogues that introduce a nitrogen outside of the macrocyclic cavity. Two novel N-confused type porphyrins were targeted for this study. Both syntheses use the key intermediate 4-quinolizone. Previous studies of N-confused pyriporphyrin showed that the system is nonaromatic and resembles structurally analogous benziporphyrins. However, modifications to systems of this type can introduce aromatic characteristics. The first system targeted introduced a quinolizone subunit into a porphyrin system. Quinolizone contains a thermodynamically stable amide and this unit disrupts the aromatic pathway. However, dipolar resonance contributors can potentially reinstate some aromatic character. A quinolizone dialdehyde was condensed with tripyrranes …

The Effect Of Amino Acids And Molar Peroxide Ratio On The Oxidation Of 2,4 Dinitroanisole In An Ultraviolet Light Emitting Diode/H2O2 Advanced Oxidation Process, Jeffry P. Hart

Theses and Dissertations

2,4 Dinitroanisole (DNAN) is an organic insensitive munition that is a likely candidate to replace trinitrotoluene (TNT) for a variety of purposes. Advanced Oxidation Processes (AOPs) are a promising method that have the potential to reduce a variety of persistent chemicals, however, the performance of these systems may be degraded by co-contaminants in the influent. In this contribution, DNAN, with casamino acids as a co-contaminant, was oxidized with Ultraviolet (UV) Light Emitting Diodes (LEDs) with hydrogen peroxide (H₂O₂) in an AOP in a laboratory. The UV/ H₂O₂ AOP was capable of degrading DNAN …

Using Molecular Dynamics Simulations To Understand Receptor-Complex Communication And Signaling, Hannah Margaret Hoag

Theses and Dissertations

The overarching purpose of this document is to use Computer-aided drug design and Molecular dynamic simulations to better understand elusive drug-receptor interactions, as well as various types of inter-receptor signaling. Chapter One introduces the theory and importance of Computer-aided drug design and the methodology used in both Chapters Two and Three.

Chapter Two uncovers the relationship between the well-studied ABCB1 transporter and a newly identified drug known as Xanthohumol (XN). XN is compared to a commonly used drug, Doxorubicin (DOX), in this chapter. If the ABCB1 transporter can be properly inhibited, cancer-fighting drugs will be able to stay within the …

Cape Gooseberry Husk For The Removal Of Cecs From Wastewater: A Biosorption Study, Jehan Abdel Salam

Theses and Dissertations

Food and beverage industries produce large amounts of fruit wastes that are normally discarded every year. Meanwhile, these industries along with the pharmaceutical industries discharge wastewater effluents that are loaded with contaminants of emerging concern (CECs). Recent research is directed towards finding alternative cost effective and sustainable solutions for treating wastewater. In this regard, we investigated cape gooseberry husk as a potential biosorbent for the removal of caffeine (CA) and salicylic acid (SA), as examples of CECs, from wastewater. Three different types of husk were investigated; un-activated husk (H), and chemically activated husks (H350 and H500) prepared by acid treatment …

Experimental And Computational Design Of Nanostructured Materials For High Performance Supercapacitor Devices, Basant A. Ali

Theses and Dissertations

Both energy conversion and storage technologies need to be developed hand-to-hand simultaneously to overcome the energy crises. To this end, supercapacitors (SCs) have the potential to be the energy storage platform due to their fast charging capability and long cycling stability. However, their low energy is the bottleneck towards their wide implementation compared to batteries. Also, current research is based on guess and check methods to modify electrode materials with limited properties prediction. In this thesis, density functional theory (DFT) has been employed as a tool to identify potential SC electrode materials. Then, the gained knowledge was used to develop …

Nanoengineered Materials For Energy Conversion & Storage Applications: A Density Functional Theory Study, Ahmed Biby

Theses and Dissertations

The conventional approach for the development of novel materials has become long relative to the desired product development cycle. Thus, the sluggish pace of the development of materials within the conventional approach hinders the rapid transformation of the scientific outcomes into useful technological products. To this end, the field of hierarchical materials informatics evolved to bridge this gap. In this field, the multiscale material internal structure is considered the starting point and the core of this approach. This being said, the density functional theory (DFT) was used to generate useful materials data for the advancement of the hierarchical materials data-bases …

Synthesis And Cytotoxicity Of Trisubstituted Imidazoles, Venkata Agasthya Kasibotla

Theses and Dissertations

Aza heterocyclic compounds are an important class of organic compounds that play a major role in medicinal chemistry. Majority of the heterocyclic motifs such as imidazoles, triazoles, piperazines etc. act as building blocks for synthesizing active pharmaceutical ingredients. Several pharmaceutical drugs include these motifs due to their varying physicochemical properties, which enable them to exhibit wide range of pharmacological activities ranging from anti-fungal, anti-neoplastic, anti-helmintic, anti-microbial etc. Owing to their electron rich ring system, imidazole and piperazine based motifs have become an attractive target for design and development of novel chemical structures as new drugs. In the current study, we …

Design And Synthesis Of Non-Xanthone Structural Analogs Of Α-Mangostin, Maryam Foroozmehr

Theses and Dissertations

α-Mangostin belongs to a class of polyphenolic compounds called xanthones. The potential pharmacological effects such as anti-bacterial and anti-cancer effects of α-mangostin have made it an important natural product for medicinal chemistry evaluation. During this thesis research, we have designed and synthesized a series of non-xanthone analogs of α-mangostin for medicinal chemistry evaluation. A commercially available starting material, methyl-4-methoxysalicylate was used to synthesize these non-xanthone analogs. The analogs were designed as more flexible derivatives compared to the tricyclic motif within α-mangostin yet retain the hydroxybenzoate scaffold. Through a one-pot chemical synthesis, with relatively high yield (70%), we prepared eight different …

Multiplexed Nucleic Acid Sensing With Single Molecule Fret, Anisa Kaur

Theses and Dissertations

In recent years, biomarkers have drawn tremendous interest in the fields of clinical diagnostics and biotechnology. In fact, recent quests for biomarker analyses have discovered a myriad of disease-related biomarkers spanning a wide variety of biomolecules such as proteins, nucleic acids, and small molecule ligands. While the detection of only one target at a time is the most common practice in biosensing today, it has been shown that the accuracy of diagnosis increases significantly by measuring the level of multiple biomarkers instead of just one due to the possible overlap of certain biomarkers in more than one disease. However, currently …

Single Molecule Investigations Of Holliday Junction Binding Protein Ruva, Dalton Reed Gibbs

Theses and Dissertations

DNA breaks are inevitable as they mainly occur due to cells’ own reactive oxygen species (ROS). While DNA breaks can be single-stranded or double-stranded, the double-stranded DNA (dsDNA) breaks are more dangerous. If such damage is not repaired, it can lead to genetic instability and serious health issues including cancers. One way dsDNA breaks can be repaired is via a process called homologous recombination (HR), which involves several DNA-binding proteins. Therefore, to have a better insight into the repair mechanism and origin of repair defects, we need a better understanding of how these proteins interact with DNA itself and DNA …

Information Architecture For A Chemical Modeling Knowledge Graph, Adam R. Luxon

Theses and Dissertations

Machine learning models for chemical property predictions are high dimension design challenges spanning multiple disciplines. Free and open-source software libraries have streamlined the model implementation process, but the design complexity remains. In order better navigate and understand the machine learning design space, model information needs to be organized and contextualized. In this work, instances of chemical property models and their associated parameters were stored in a Neo4j property graph database. Machine learning model instances were created with permutations of dataset, learning algorithm, molecular featurization, data scaling, data splitting, hyperparameters, and hyperparameter optimization techniques. The resulting graph contains over 83,000 nodes …

Computational Study Of Radical Cation Rearrangements, Mi'kayla D. Word

Theses and Dissertations

A radical cation is a molecule that has one unpaired electron that holds a positive charge. The unpaired electron within a radical cation causes the molecule to be reactive. The high reactivity of these species allows for radical cations to be commonly studied experimentally using mass spectrometry and other multi-mass imaging techniques. However, these methods often cannot resolve the reaction mechanisms for these fast reactions. Specifically, radical cation rearrangement mechanisms are particularly unresolved within experiments. For this reason, radical cation rearrangements are computationally investigated to explain complex reaction pathways for processes to understand reactions leading to the initiation of detonation …

Bisphosohoglycertae Mutase: A Potential Target For Sickle Cell Disease, Anfal S. Aljahdali

Theses and Dissertations

Bisphosphoglycerate mutase (BPGM) is a part of the erythrocyte glycolysis system. Specifically, it is a central enzyme in the Rapoport-Leubering pathway, a side glycolytic pathway involved in the regulation of the concentration of the natural allosteric effector of hemoglobin (Hb), 2,3-bisphosphoglycerate (2,3-BPG). BPGM catalyses the synthesis and hydrolysis of 2,3-BPG through its synthase and phosphatase activities. The synthase activity is the main role of BPGM, while the phosphatase activity is low and is activated by the physiological effector, 2-phosphoglycolate (2-PG) with the latter mechanism poorly understood.

BPGM activity and 2,3-BPG levels in red blood cells (RBCs) have a significant role …

Nanopore Detection Of Long Time-Scale Single Metallic Cluster Conformational Changes And Surface Ligand Exchange, Bobby D. Cox

Theses and Dissertations

Single molecule nanopore spectroscopy serves as an emerging tool for studying small molecules in aqueous environments without the need for additional chemical labels. Recently it has been seeing increased use as a tool for investigating small metallic nanoparticles and clusters. These clusters consist of a handful of metallic atoms (e.g. Au18) and are regularly ‘passivated’ with organic ligands to provide functionality and protect against aggregation. There has been a widening gap in research studying the surface kinetics of these passivating ligands at the single molecule level as well as during the exchange process. In this work we investigated these surface …

Single-Molecule Investigation Of I-Motif Folding And Dynamics In Bioinspired Dna Platforms, Anoja Megalathan

Theses and Dissertations

Although the canonical right-handed B-DNA is the predominant form of DNA in cells, DNA can adopt other secondary structures such as hairpins, G-quadruplexes (G4), and intercalated motifs (i-motif). These secondary structures are typically formed in the regions with repeat sequences. Among many secondary structures DNA can adopt, G-quadruplexes and i-motifs (tetraplex structures formed in the G-rich and C-rich sequences, respectively) caught significant research interest in recent years due to the prevalence of G-rich and C-rich sequences in the human genome. While G-quadruplexes are extensively studied, little is known about i-motifs – especially their formation and stability under cellular environments. For …

Conformational Modulation Of Α-Helical N-Acetylated Α-Synuclein, Ricardo Fernandez

Theses and Dissertations

Human N-acetylated α-synuclein (^NAcαSyn) has long been accepted as an intrinsically disordered protein (IDP) predominantly found in terminal nerve regions in healthy subjects. ^NAcαSyn structural fluidity enables the formation of transient or dynamic assemblies. Some of these assemblies may serve functional, yet undefined purposes. ^NAcαSyn is highly susceptible to the surrounding environment, leading to misfolding under high cytosolic oxidative stress conditions, which in turn assemble in the form of toxic oligomers or amyloid fibrils. These ^NAcαSyn inclusions along with their accretion and migration within neurons, are pathological hallmarks of Parkinson’s disease (PD), dementia, and multiple …

Streptococcus Sanguinis: The Good, The Bad, And The Metal-Binding Lipoprotein, Cody Murgas

Theses and Dissertations

Streptococcus sanguinis is an opportunistic bacterium living beneficially in the human mouth. When S. sanguinis gains access to the bloodstream, it can result in colonization on damaged tissue and generate heart valve vegetations that can develop into infective endocarditis. It has been suggested that Mn and Fe are cofactors in the pathogenic capacity of this bacterium, and that these redox active metals are imported by the metal binding lipoprotein S. sanguinis adhesin B (SsaB). The SsaB lipoprotein is an integral part of SsaACB, an ATP-binding cassette (ABC) transport system in S. sanguinis. When SsaB is deleted, the resulting strain displays …

Ligand Effects On Electronic, Magnetic, And Catalytic Properties Of Clusters And Cluster Assemblies, Dinesh Bista 9288522

Theses and Dissertations

Ligands commonly protect metallic clusters against reacting with outside reactants. However, ligands can also be used to control the redox properties enabling the formation of super donors/acceptors that can donate/accept multiple electrons. This thesis focuses on how the ligands can be used to control the electronic and magnetic features of clusters and ligand stabilized cluster-based assemblies, leading to nano pn junctions with directed transport, the possibility of light-harvesting, and catalysts for cross-coupling reactions. The thesis addresses three distinct classes of clusters and their applications. The first class of cluster “metal chalcogen clusters” is the central idea of the thesis focused …

Nebulizer-Based Systems To Improve Pharmaceutical Aerosol Delivery To The Lungs, Benjamin M. Spence

Theses and Dissertations

Combining vibrating mesh nebulizers with additional new technologies leads to substantial improvements in pharmaceutical aerosol delivery to the lungs across therapeutic administration methods. In this dissertation, streamlined components, aerosol administration synchronization, and/or Excipient Enhanced Growth (EEG) technologies were utilized to develop and test several novel devices and aerosol delivery systems. The first focus of this work was to improve the poor delivery efficiency, e.g., 3.6% of nominal dose (Dugernier et al. 2017), of aerosolized medication administration to adult human subjects concurrent with high flow nasal cannula (HFNC) therapy, a form of continuous-flow non-invasive ventilation (NIV). The developed Low-Volume Mixer-Heater (LVMH) …