Physical Sciences and Mathematics Commons^™

Community-Based Research Methods To Inform Public Health Practice And Policy: The Case Of Lead In The Mississippi Delta, Mary Alexandra Fratesi

Honors Theses

Environmental health issues are complex and require interdisciplinary and community engagement approaches to better understand them and inform policy. As one example, lead exposure has a number of dangerous neurological effects, including developmental delays and learning deficits. Potential lead exposure through drinking water and paint are areas of concern. In a 2018 document, the Environmental Protection Agency (EPA) estimated that up to 20% of lead exposure comes from drinking water alone. By using a type of engagement research called community-based research (CBR), this project began to address this major public health issue. CBR can be used to connect residents, their …

Cigarette Litter Leachates: A Statistical Study Of Elements In Freshwater And Saltwater, Cintly Guzman Hernandez

Honors Theses

Cigarette butts are the most common item found in coastal litter cleanups as approximately 4.5 trillion smoked cigarette butts are discarded into the environment every year. Cigarette butts can leach toxic heavy metals and nicotine along with other compounds from tobacco combustion. Past research in our lab has analyzed elements leached from cigarette butts into freshwater. The cigarette butts consisted of smoked and unsmoked butts that were soaked varying periods of time, and at different pH levels to identify the relationship of these variables to the amount of metal leached. The elements analyzed were Al, Ba, Cd, Cr, Cu, Fe, …

Electro- And Photocatalytic Carbon Dioxide Reduction With Mononuclear And Dinuclear Rhenium Polypyridyl Complexes, Eva Amatya

Honors Theses

The main challenge of reducing carbon dioxide (CO2) to value-added products lies in designing more efficient catalysts that are long-lived, selective, and operate near the thermodynamic potential for the reaction. In this work, mononuclear and dinuclear Re complexes containing diamine ligands linked to a pendant anthracene moiety have been synthesized and studied for both electrocatalytic and photocatalytic CO2 reduction. Electrocatalytically, the performances of both catalysts were studied in N,N-dimethylformamide (DMF) and acetonitrile (MeCN) solutions to determine their turnover frequencies (TOFs) for CO2 reduction. Catalyst performance was compared to previously reported rhenium systems, and both systems studied here were shown to …

Synthesis And Characterization Of Organically Modified Hectorites For Sequestration Of Pfaas From Contaminated Drinking Water, Alexandra Pagano

Honors Theses

Perfluoroalkyl Acids (PFAAs), a family of industrial chemicals, are found in household products such as pizza boxes, microwave popcorn bags, and non-stick pans. PFAAs of different carbon chain lengths and ionic head groups exist, such as PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonic acid). Used without regulation in industry for decades, PFAAs only recently became recognized as contaminants of emerging concern, since they are bioaccumulative in organisms, persistent in the environment, and toxic. PFAAs are known to accumulate in the blood, liver and kidneys, and drinking water contaminated with PFAAs has been linked to certain types of cancer. Therefore, it …

Optimization Of Superhydrophobic Surface Production Using Ambient-Dried Silica-Based Aerogels, Elizabeth Donlon

Honors Theses

Superhydrophobic surfaces exhibit particular properties that make them functional in various anti-sticking, anti-contamination, self-cleaning and drag reduction applications. Though such surfaces are found in nature - most notably the lotus leaf - they are difficult to produce. There are numerous methods and techniques for fabricating superhydrophobic surfaces. One such method is the sol-gel method, in which aerogel, a highly porous and lightweight material that can be made hydrophobic or superhydrophobic, is coated onto a surface. The purpose of this project is to devise a simple and repeatable procedure for making hydrophobic silica aerogel coatings that can be used for drag …

Pro-Antimicrobial Networks Prepared Via Degradable Thiol-Ene Acetal Photopolymerization, Sarah Swilley

Honors Theses

A degradable, antimicrobial polymer network with acetal crosslink junctions derived from p-anisaldehyde (pA), a common constituent found in star anise extract, is reported. The p-anisaldehyde was converted into a bis-functional acetal alkene monomer, which serves as a pro-antimicrobial form of the active aldehyde and a building block for materials referred to as pro-antimicrobial polymer networks via degradable acetals (PANDAs). Subsequently, the bis-functional acetal alkene monomer was photopolymerized with a multifunctional thiol to yield a thiol-ene network. PANDAs exhibit surface erosion behavior and yield sustained release of pA over 38 days when exposed to neutral or biologically relevant conditions. The pA …

Biocompatible, Responsive Polysoaps Via Raft Copolymerization For The Delivery Of Model Cancer Therapeutics, Mason Dearborn

Honors Theses

Many chemotherapeutic drugs are small, hydrophobic molecules that require water-soluble, biocompatible nanocarriers for enhanced vascular circulation. Existing polymeric carriers either conjugate the drug along a copolymer backbone or sequester drugs within a protected interior domain to be delivered to specific sites in the body. Such therapeutic systems must overcome a myriad of hurdles, beginning with complex, multi-step syntheses, followed by other inherent barriers that limit the efficiency of drug delivery at the targeted site. This work aims to circumvent a number of these issues using biocompatible, stimuli-responsive polysoaps that are capable of unimeric micelle formation, hydrophobic drug delivery, and triggered …

An Exploration Of Pyrrole Groups On The Enantioselectivity Of Pig Liver Esterase, Brian Long

Honors Theses

Pig Liver Esterase (PLE) is a serine protease enzyme that can interact with one side of a diester to hydrolyze the ester to a carboxylic acid, and research has found that the level of hydrophobicity of side groups can impact the enantioselectivity of PLE hydrolysis.1, 2 The Jones Model is what current researchers use to model the active site of PLE, but the nature of its binding pockets, namely the Hydrophobic Long (HL) pocket, has been called into question.3 Dimethyl 2-((pyrrole-2-yl)methyl)-2-methylmalonate was prepared to be subjected to PLE hydrolysis to see whether enantioselectivity was found. Chiral HPLC revealed 25.32% enantiomeric …

Understanding The Coating-Substrate Interface Changes And Degradation Caused By Environmental Acclimation With Water And Electrolytes, Russell Vick

Honors Theses

While it is well known that polymeric coatings are used to protect metals from corrosion, efficient and reliable protocols for quantifying and estimating protective coatings’ lifetimes have yet to match real-time results in rate or in detected mechanisms of material failure. Alkoxysilane pretreatments are widely utilized for substrate preparation and improved coating system performance by changing the metal substrate surface morphology to improve adhesion at the coating-substrate interface by creating a foundation and excluding water from the system. Three pretreatments used were 3-aminopropyltriethoxy silane (APS), tetraethylortho silicate (TEOS), N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAS). They were investigated to improve the understanding of the relationships …

Treating Breast Cancer With Light: The Creation Of Two Photodynamic Therapy Agents, Victoria Lackey

Honors Theses

Photodynamic therapy (PDT) is a treatment for a wide display of diseases, including cancer, that has become gradually widespread. The procedure requires the usage of photosynthesizing agents, which are activated in the presence of light. One quite successful photodynamic therapy agent is an aromatic structure made up of four pyrrole rings called a porphyrin. This research focused on producing the water-soluble porphyrins, H2TPP-3-PEG-OH and H2TPP-PiperMe-OH, through the attachment of the starting porphyrin, H2TPPC, with 3-polyethyleneglycol and 3-piperidinemethanol, respectively. The novel, water-soluble agent was purified and characterized by infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), and UV-vis spectroscopy. Purity was …

Diastereoselective Synthesis Of 2,4,6-Trisubstituted Piperidines Via Aza-Prins Cyclization, John A. Hood

Honors Theses

The nitrogen heterocycles are shared amongst 59% of Food and Drug Administration (FDA) approved small molecule pharmaceuticals with the six-membered piperidine representing the most common moiety. Given the versatility and potential to yield derivatives with broad biological activities, the discovery of new chemical methods to generate these heterocycles in a more time and cost-efficient manner is desired. While there are existing racemic methods to access this class of molecule, the objective of this research is to pioneer a new novel six-step method to generate 2,4,6-trisubstituted piperidines with stereoselective control.

The first step is a condensation between a nonenolizable aldehyde and …

Photoelectrochemical Investigations On Novel Earth Abundant Solid State Catalysts For Solar Water Oxidation, Nathaniel Branimir Kurtz

Honors Theses

In light of a looming fossil fuel scarcity, many forms of alternative, clean energy production are being researched in order to provide a more sustainable source of energy production for the future. One area of research is on using novel, abundant catalytic materials in conjunction with semiconducting materials to drive the splitting of water in order to produce hydrogen gas, an energy-rich fuel. Currently, efficiency is limited by the energy bottleneck posed by the oxygen evolution reaction (OER) half of water splitting. In this work, cobalt selenide (CoSe) catalyst paired with the semiconductor iron oxide (Fe2O3) has been identified as …

Investigation Of The Effects Of Hydrogen Bonding On The Enantiomeric Excess Of Pig Liver Esterase Hydrolysis Products, Matthew Hasler

Honors Theses

Pig Liver Esterase (PLE) is an effective enzyme used in the Masterson Research Group due to its ability to hydrolyze only one ester in a malonic diester. PLE is employed for creating chiral molecules for the synthesis of unnatural amino acid precursors. Previous research in the group found that malonic half esters with hydrogen bonding capable substrates yielded varying degrees of enantiomeric excess, and non-hydrogen bonding substrates yielded racemic mixtures.1,2 The compounds synthesized contained substrates consisting of thiophene rings in the second and third position, and these molecules act as a control for the other research done in the group. …

Sds-Page Analysis Of Modified Lysozyme By Substituted Benzoquinones And Naphthoquinones, Neethu Kurien

Honors Theses

Quinones are molecules that are commonly found in the environment, as cofactors for proteins or an electron carrier in the mitochondrial electron transport chain. However, quinones also can come from polycyclic aromatic hydrocarbons as their metabolites, harming cellular integrity. In this study, we investigated protein modification of lysozyme in the presence of substituted benzoquinones and naphthoquinones. To simulate physiological conditions, all reactions used phosphate buffer (50.0 mM). While the majority of the experiments were performed at 37 C and pH 7.0, there were also temperature dependence (27 C and 42 C) and pH dependence (6.0 and 8.0) reactions included. SDS-PAGE …

Phospholipid Membrane Remodeling Through Exogenous Fatty Acid Incorporation In Certain Bacterial Species, Josh Herndon

Honors Theses

Multi-drug resistant bacteria have become problematic in healthcare settings. Recent studies have documented the ability of some bacteria, such as Vibrio species, to assimilate exogenous fatty acids into their membrane phospholipids. Therefore, the current research was performed to determine whether the three virulent, multi-drug resistant bacteria Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli can remodel their cell membranes following exposure to a range of exogenous polyunsaturated fatty acids (PUFAs). Furthermore, we hypothesized that PUFAs would influence phenotypes associated with growth and virulence. Extracted phospholipids were examined by UPLC/MS analysis to confirm assimilation of exogenous PUFAs into the bacterial phospholipids. A. …

Evaluating Mutagenicity Of Burned Arginine-Based Heterocyclic Amines And Anti-Mutagenicity Effect Of Chinese Medicinal Herbs, Rayford C. Alva

Honors Theses

From the unexpected finding that cooked grains and meat substitutes elicit a mutagenic response in Salmonella typhimurium TA98, our work has been aimed at deconstructing this finding via a survey of heated binary amino acid combinations, involving arginine, a plant-based amino acid. secondly, our work has looked towards sing phytochemical extracts from traditional Chinese medicinal herbs to inhibit the mutagenic activity of heterocyclic amines (main culprit for mutagenicity in meat). Two fractions from the burned products of arginine and phenylalanine (RF-HCA-06 and -07) were statistically significant inducers of mutagenesis; Scutellaria barbata and Oldenlandia diffusa, both separately and together, were statistically …

Synthesis Of Oxygenated Boronic Acid Substituted A-Cyanostilbenes For Use As Antibacterial, Yewon Kim

Honors Theses

Stilbenes are naturally occurring compounds that have exhibited antibacterial activity, although the biological effect of various stilbenes differs for Gram-positive and Gram-negative strains of bacteria. In prior research, cyanostilbenes have shown slight antibacterial activity (Brownlee, et al. 1943). This project aims to explore whether hybrid oxygenated a-cyanostilbenes possessing a boronic acid pharmacophore exhibits significant antibacterial activity (Das et al. 2013). The biological activity against Staphylocococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) was tested using the Kirby-Bauer text. No inhibition of E. coli growth was shown while S. aureus was partially inhibited.

The Impact Of The 515nm Effect On 1o2 Quenching In Photosynthesis: Model System Studies Using Β-Carotene–Acid Complexes, Lauren A. Hoody

Honors Theses

β-carotene (βC) is an orange pigment present in the photosynthetic reaction center (PRC) of green plants, where it plays a vital role in photosynthesis: It quenches singlet oxygen (1O2 , a toxic oxidizing species generated during photosynthesis) before the 1O2 damages chlorophyll and other components of the PRCs. During photosynthesis, βC temporarily converts from its native orange–450 state to a pink–515 state via the so–called 515nm Effect. Because of the differences between the electronic structures of orange–450 and pink–515, I hypothesize that pink–515 will quench 1O2 less efficiently than orange–450. This hypothesis has not been tested to date because orange–450 …

Modifications To Para-Menthane-(3,8)-Diol To Increase Mosquito Repellency, Heidi Nowakowski

Honors Theses

No abstract provided.

Silicon And Tin Substituted Halocyclopropanes: Approaches To New Carbenes And Strained Cyclic Allenes, Noura Srour

Honors Theses

Chloro(trimethylsilyl)carbene and chloro(trimethylstannyl)carbene were generated through photolysis of cyclopropanated phenanthrene precursors which were synthesized in two steps. The photolysis reactions were done in the presence of cis and/or trans-beta-methylstyrene. Though product peaks corresponding to the carbene-alkene adducts were observed in the GCMS, the yields were too low for their isolation and complete characterization. Density functional theory (DFT) calculations were performed on the stereoisomers of the precursor to Chloro(trimethylsilyl)carbene and the carbene itself. Surprisingly, Chloro(trimethylsilyl)carbene’s triplet state was found to be more stable than the singlet at this level of theory.

In a related project, (1-bromo-1a,9b-dihydro-1H-cyclopropa[l]phenanthren-1-yl)trimethylstannane, was …

Development Of A Gel Assay For Analysis Of Bovine Milk Casein, Masa Miscevic

Honors Theses

The main purpose of this research was to develop a gel assay for analysis of casein samples for ultimate application for studies of in vitro models for stomach and intestinal processing of dairy products in adults and infants. It is proposed that casein completely dissolves and is digestible in simulated gastric, and is somewhat soluble and digestible in simulated intestinal environments of adults and infants. The following experimental methods were devised to thoroughly examine behavior and properties of casein originating from different sources in range of solvents and varying pH values. First, casein was enriched in comparison to soluble materials …

O-Glcnac Post Translational Modification Of Hypoxia-Inducible Factor (Hif) Proteins, Hailey Elisabeth Grisham

Honors Theses

O-linked β-N-acetylglucosamine (O-GlcNAc) post-translational modification (O- GlcNAcylation), plays a vital role in many metabolic pathways, including those of numerous diseases. New research methods and basic functional roles of O-GlcNAc post- translational modification on metabolism, human health, and cancer are quickly developing, but a vast amount of research remains on the specificity of this pathway towards specific proteins. In this study, T47D breast cancer cells were used as an in vitro model to investigate the effects of O-GlcNAc modification on hypoxia-inducible factor (HIF) proteins.

Cell-Free Telomere Dna As A Biomarker For Treatment Response And Tumor Burden In Glioblastoma, John P. North

Honors Theses

Telomeres are repeated nucleotide sequences that cap the ends of each chromosome in eukaryotes. Telomeres are among the earliest genomic sequences to be degraded during apoptosis, potentially providing a biomarker of cell death. To study this, we quantified telomeres in serum from Glioblastoma and non-cancer patients. Cell-free DNA was isolated by centrifugation to remove intact cells, and purified using a QIAamp DNA Blood Midi Kit (Qiagen). Cell-free telomeric (cf-tel) and cell-free actin (cf-actin) DNA were analyzed with quantitative PCR. Total cell-free DNA was measured with PicoGreen assays. We hypothesize that patients with Glioblastoma tumors have higher cf-tel DNA levels than …

Assembly Of A Protein-Based Hydrogel As A Vehicle For In Situ Drug Delivery, Austin Carroll

Honors Theses

The goal of this work is to develop a self-assembling, protein-based gel to deliver drugs at the site of chronic inflammation. There are two engineered protomers that comprise the gel; calmodulin- and M13- are their critical components. Numerous enzymes have been shown to undergo calcium-dependent regulation by calmodulin, an intracellular protein highly resilient to its chemical environment. One of these enzymes, myosin light chain kinase, contains a remarkable 26 residue portion known as the M13 peptide that has been demonstrated to bind to calmodulin in the presence of calcium through hydrophobic interactions. Because the extracellular space in vivo constitutes an …

An Analysis Of Commercial Oxidative Hair Dyes Using Raman Spectroscopy, Allyson Henke

Honors Theses

Here, we aim to further the potential use of surface-enhanced Raman spectroscopy (SERS) in analyzing hair dyes for use in forensic investigations. Current methods include light microscopy and thin-layer chromatography (TLC). However, these techniques can be destructive to the hair samples, do not have high discriminatory power, and have had problems with giving inconclusive results. Raman spectroscopy, on the other hand, is a fast, simple technique with a high discriminatory power. Previous work has shown that SERS can be used for in-situ analyses that is not destructive to the sample. This previous work also demonstrated that SERS could definitively differentiate …

Targeting Metastatic Breast Cancer With Statin Drugs And Coq10, Jacob Thrasher

Honors Theses

Statin drugs are commonly prescribed to lower cholesterol levels in patients, but recently statins have been under investigation as a potential anti-cancer drug. Statins are HMG-CoA reductase inhibitors and subsequently inhibit the mevalonate pathway and cholesterol synthesis. Since cholesterol trafficking is vital in the growth and metastasis of cancer, statin drugs are being studied to explore their effects on cancer cells. CoQ10, one of the products from the mevalonate pathway, also has shown some potential anti-cancer properties, but its use to combat cancer is controversial. While some studies have shown that CoQ10 supplements can be synergistic with other cancer treatment …

Studying The Effects Of Hydrogen Bonding In 1h-1,2,3-Triazole And Its Derivatives, Leah Alexandra Wallace

Honors Theses

1,2,3-triazole is used as a building block in many pharmaceutical drugs. The molecule has several derivatives that are useful in other areas including treating fungal infections and in dealing with some environmental issues. One of its derivatives, benzotriazole, is commonly used as an inhibitor of corrosion through the formation of a copper-benzotriazole complex. One area of particular interest in studying triazoles is the ability of these molecules to tautomerize. The hydrogen atom can move from the 1H position to the 2H position and this transfer is thought to be affected by solvent interactions. Here, we study the effects of hydrogen …

Stable Bromine Isotope Signature Of Bromoform From Enzymatic And Abiotic Formation Pathways And Its Application In Identifying Sources Of Environmental Bromoform In The Damariscotta River, Chengyang Wang

Honors Theses

Bromoform is a major source of atmospheric bromine. Most bromoform is produced by marine organisms including macroalgae and phytoplankton, using the enzyme bromoperoxidase (BPO). Bromoform can also be a byproduct of industrial processes such as water disinfection. Identifying sources of environmental bromoform is still a challenge. A novel technique of using quadrupole mass spectrometry coupled to a gas chromatography (GCqMS) was developed and optimized for Br isotope analyses. The study shows that GCqMS in single ion monitoring (SIM) mode can measure 81Br with precision of around ±0.7‰ (60pmol bromoform injected). This study aims to investigate stable Br isotopes of bromoform …

Raman Spectroscopic And Computational Study Of Hydrogen Bond Interactions Between Guanidine Hydrochloride, Trimethylamine N-Oxide (Tmao), Urea, And Water, Andrew Kamischke

Honors Theses

Proteins are broken down in the body and produce water, CO2, and ammonia as by-products. Ammonia is toxic to cells, making it a priority to be excreted. Urea is the key route for the transportation of ammonia out of the body and is the main component of urine. Guanidine is another important nitrogen-containing molecule that is structural like urea and plays important biological roles in the stabilization of proteins. Guanidine hydrochloride and Urea are known to denature proteins and this functionality continues to be a topic of great interest. Urea and guanidine contain many hydrogen bonding sites and interactions with …

Studies Of Carbonaceous Materials Using Raman Spectroscopy, Cameron L. Smith

Honors Theses

Various carbonaceous materials including graphene, treated biochar, and C60 were studied using Raman spectroscopy with particular attention given to the treatment process and the Raman enhancement methods. Such studies that focus on the treatment process are useful in determining the extent to which the species was affected via shifts in the Raman peaks. Previous collaborations have proven successful when multiple samples were studied and analyzed. The attempt to create a novel Raman enhancement technique via combination of two previously recorded techniques was ultimately unsuccessful but further work is necessary.