Chemistry Commons^™

Temporal Changes And Possible Sources Of Dissolved Calcium Levels In Stream, River, And Lake Waters In Western Kentucky, Kelsie Meystedt

Scholars Week

ABSTRACT

Zebra Mussels (Dreissena polymorpha) are an exotic and invasive mollusk that spread extensively over various rivers and lakes in the United States. These mussels are known for being notorious in their “biofouling” capabilities, costing the U.S. government billions of dollars in removal operations. Recently, zebra mussel colonies were found in Kentucky Lake possibly due to human activities increasing the salinity of today’s freshwater resources. The increase in salinity from human activities may have adversely affected the ecosystems and water supplies. The Specific aim of this study was to determine the temporal trend of dissolved calcium in Kentucky Lake …

Characterization Of Competitive Inhibitors Of Plasmodium Falciparum Cgmp-Dependent Protein Kinase**, Tyler Eck, Mariana Laureano De Souza, Melvin Delvillar, Kutub Ashraf, Rammohan R. Yadav Bheemanaboina, Ramappa Chakrasali, Tamara Kreiss, John J. Siekierka, David P. Rotella, Purnima Bhanot, Nina M. Goodey

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Plasmodium falciparum cGMP-dependent protein kinase (PfPKG) is an enticing antimalarial drug target. Novel chemotypes are needed because existing inhibitors have safety issues that may prevent further development. This work demonstrates isoxazole-based compounds are potent ATP competitive inhibitors of PfPKG and discloses a new analogue in this series. Isoxazoles 3 and 5 had Ki values that are comparable to a known standard, 4-[2-(4-fluorophenyl)-5-(1-methylpiperidine-4-yl)-1H pyrrol-3-yl] pyridine. They also exhibited excellent selectivity for PfPKG over the human orthologue and the gatekeeper mutant T618Q PfPKG, which mimics the less accessible binding site of the human orthologue. The human orthologue's larger binding site volume is …

Solid Organic-Coated Ammonium Sulfate Particles At High Relative Humidity In The Summertime Arctic Atmosphere, Rachel M. Kirpes, Ziying Lei, Matthew Fraund, Matthew J. Gunsch, Nathaniel W. May, Tate E. Barrett, Claire E. Moffett, Andrew J. Schauer, Becky Alexander, Lucia M. Upchurch, Swarup China, Patricia K. Quinn, Ryan C. Moffet, Alexander Laskin, Rebecca J. Sheesley, Kerri A. Pratt, Andrew P. Ault

Pacific Faculty Work

The ability of atmospheric aerosols to impact climate through water uptake and cloud formation is fundamentally determined by the size, composition, and phase (liquid, semisolid, or solid) of individual particles. Particle phase is dependent on atmospheric conditions (relative humidity and temperature) and chemical composition and, importantly, solid particles can inhibit the uptake of water and other trace gases, even under humid conditions. Particles composed primarily of ammonium sulfate are presumed to be liquid at the relative humidities (67 to 98%) and temperatures (22 to 4°C) of the summertime Arctic. Under these atmospheric conditions, we report the observation of solid organic-coated …

Probing Small Heat Shock Protein Chaperoning Activity Through The Interaction Between Myoglobin And Guanidine Hydrochloride, Jacob Mcdowell

Celebration of Research

Myoglobin is a small biological protein found in most muscle tissues. When in the proper form (native/folded), myoglobin can serve its primary function: binding oxygen. However, like all proteins, myoglobin can denature through a variety of processes into a form that no longer binds oxygen. One denaturant, guanidine hydrochloride (GuHCl), is the biological product of protein metabolism. Another class of biological proteins is small heat shock proteins (sHSPs), which have the function of chaperoning other proteins to prevent the denaturing process. Previously, in physical chemistry lab, we explored the GuHCl-induced denaturing of myoglobin. Former Northwestern students used fluorescence correlation spectroscopy …

Amino Acid Quenching, Steven Van Meeteren

Celebration of Research

Alexa Fluor 594 is a fluorescent molecule commonly used to tag calmodulin, a protein that regulates a variety of cell processes. By measuring fluorescence, scientists can study calmodulin and its interactions with other proteins. However, fluorescence is not the only fate of Alexa Fluor 594. The molecule is also known to transfer energy to coupled amino acids through a mechanism called quenching. The purpose of this experiment was to study the quenching effects of Histidine, Tyrosine, and Methionine on the Alexa Fluor 594. These amino acids’ Stern-Volmer plots suggest static quenching may be occurring. Moreover, the Stern-Volmer plot of Potassium …

Researching The Molecular Components Of Flourish Using Mass Spectroscopy, Lane Mulder

Celebration of Research

We looked into the molecular composition of a liquid probiotic known as Flourish and and the 13 components that make it up using mass spectroscopy.

Faster Intercalation Pseudocapacitance Enabled By Adjustable Amorphous Titania Where Tunable Isomorphic Architectures Reveal Accelerated Lithium Diffusivity, Wessel Van Den Bergh, Taylor Larison, Maximilliano Jesus Jara Fornerod, Prof. Stefan Guldin, Morgan Stefik

Faculty Publications

Intercalation pseudocapacitance is a faradaic electrochemical phenomenon with high power and energy densities, combining the attractive features of capacitors and batteries, respectively. Intercalation pseudocapacitive responses exhibit surface-limited kinetics by definition, without restriction from the collective of diffusion-based processes. The surface-limited threshold (SLT) corresponds to the maximum voltage sweep rate (vSLT) exhibiting a predominantly surface-limited current response prior to the onset of diffusion-limitations. Prior studies showed increased lithium diffusivity for amorphous titania compared to anatase. Going beyond prior binary comparisons, here a continuum of amorphous titania configurations were prepared using a series of calcination temperatures to tailor both amorphous …

Competitive Sorption And Transport Of Heavy Metals In Soil And Mn Oxide-Coated Sand, Joshua Tyler Padilla

LSU Doctoral Dissertations

This study investigated the competitive sorption of Ni, Pb, and Zn as well as synergistic interactions between Ni and phosphate (P) in soils and Mn oxide-coated sand. During stirred-flow experiments, the sorption of heavy metal cations by Olivier soil was mutually reduced when applied simultaneously. When applied consecutively, the cation of higher affinity was able to displace the cation of lower affinity from the soil surface, however, no evidence for the reverse case was observed. A novel general exchange kinetics model was able to correctly describe such displacement. Competition between Ni and Zn mutually increased mobility in Olivier and Windsor …

Bioactivity Of Suberitenones A And B, Jared G. Waters

USF Tampa Graduate Theses and Dissertations

Throughout human history, natural products have formed the foundation of medicine. In ancient times, a myriad of herbs and fungi have been attributed properties of healing and rejuvenation. Today, that foundation still very much exists, as natural product chemists isolate bioactive compounds from plants, fungi, animals, and microorganisms alike. As more of these secondary metabolites are discovered, scientists pursue more and more sources of biodiversity that may yield new and unprecedented compounds. To this end, Antarctica has become of particular note, as its unique environmental conditions and highly isolated nature make for rare and unusual adaptations in its native wildlife. …

The Analysis Of Microplastics Found In The Flowers Of Rhode Island, Hailey Hendricks, Matthew Kiesewetter

Senior Honors Projects

No abstract provided.

Identification And Quantification Of Atrazine In The North River Using Spe And Hplc, Kenneth Scott Overway, Youmna Moawad

Chemistry Faculty Scholarship

High-performance liquid chromatography (HPLC) is utilized for the separation, purification, and quantification of viscous and complex analyte mixtures. It is important in that it can analyze and detect low analyte concentrations, which can be useful in many industries, such as food and pharmaceutical industries, as well analyzing environmental samples. The purpose of this project was to identify and quantitate atrazine, an herbicide, in a water sample from the North River (Bridgewater, VA) using solid-phase extraction (SPE) and HPLC.

Comparing And Contrasting Therapeutic Drugs Vs. Lifestyle Changes That Combattype-Ii Diabetes, Alexander Cline Helmuth

Chemistry & Biochemistry Student Projects

In this thesis, I will be presenting various preventive approaches to combat type-II diabetes. The focus of this paper will be comparing and contrasting therapeutic drug targets such as Metformin and Sulfonylureas that are prescribed for type-II diabetic patients versus taking preventative steps such as making lifestyle changes including weight management, physical activity, and having a balanced diet that prevents onset of type-II diabetes or helps patients manage type-II diabetes. From this paper, one will gain insight on how there are multiple approaches to combat type-II diabetes that are not in the form of the pill.

Microfluidic Paper Analytical Devices, Madison Page

Chemistry & Biochemistry Student Projects

Microfluidic paper analytical devices (µPADs) are small, paper-based matrices similar to Lab-on-a-Chip (LOC). They are capable of semi-quantitative analysis, with applications ranging from medical to environmental to food and beverage testing. Important to improving point-of-care devices (POCs), various techniques have been integrated into µPADs to customize analysis and fit different clinical situations.

The Application Of Biological Processes To Increase Energy Potential In Landfills, Ashlyn Eisenhart

Chemistry & Biochemistry Student Projects

There has been a dramatic increase in the amount of waste that we humans have created. This has been due to population growth, an increase in industrial manufacturing, along with urbanization and modernization.⁸ The number of tons of municipal solid waste entering landfills has increased from 82.5 million tons in 1960 to 146.1 million tons in 2018.¹⁷ However, thanks to recycling, composting, and energy recovery from combustion, the percentage of solid waste going to landfills has dramatically decreased, from around 93.6 to about 65.4 percent.¹⁷

Chemistry Of Toothpaste, Kayla Blanche Kirtley

Chemistry & Biochemistry Student Projects

The chemistry of toothpaste is explained, with a description of the chemical components and their mode of action in the role of toothpaste.

Clostridioides Difficile Spore Production In Response To Antibiotic And Immune Stress, Adenrele Oludiran, Erin B. Purcell

College of Sciences Posters

Clostridioides (Clostridium) difficile, an anaerobic, spore-forming Gram-positive pathogenic bacterium, is a major cause of hospital-acquired infections and can persist as surface-attached biofilms for protection from antibiotic and immune stress. C. difficile can form biofilms as a single species or with other anaerobic intestinal bacteria. The environmental signals that cause individual cells to secrete toxins, form biofilms, or develop into spores that can spread the infection to new patients are unknown. In these studies, we investigate bacterial responses to different stress. Antimicrobial host-defense peptides (HDPs) produced by animal immune systems are promising candidates to develop novel therapies for bacterial infection …

Towards Semiconductor Nanorods With Nickel/Iron Cocatalyst., Kehinde Ayorinde

Masters Theses & Specialist Projects

The adverse effects associated with the utilization of fossil fuels has led to the need to provide an alternative cleaner energy. Photocatalytic hydrogen evolution reaction via water splitting provides a renewable pathway to generating energy. Our photocatalyst system includes a semiconductor component (CdSe/CdS core/shell nanorods) to capture light and an attached metal (cocatalyst) for the hydrogen evolution reaction. Platinum is an effective metal catalyst for this reaction due to strong proton binding energy that easily facilitates the reduction of water to produce hydrogen gas. However, due to the high cost of platinum, there is a need to find a less …

Synthetic, Photophysical, And Catalytic Studies Of Light-Harvesting Macrocyclic Complexes, Fox Bratcher

Masters Theses & Specialist Projects

Chromophores are an important class of compounds in Nature and industry, with several hundred thousand tons produced annually as dyes and pigments. Alone, these compounds absorb light unto themselves; however, several of these compounds can be combined to produce a beneficial cascading transfer of energy to a core chromophore.

In this study, photophysical properties of several covalent and axially borondipyrromethene (BODIPY)-conjugated complexes of porphyrin and salphen scaffolds have been evaluated in a series of emission and catalytic studies. In the porphyrin systems, a beneficial excited energy transfer (EET) from the BODIPY moieties to the porphyrin core was observed; however, only …

Covid-19 Pandemic Effects On The Environment, Ken Overway, Phillips Lane

Chemistry Faculty Scholarship

The coronavirus disease of 2019 (COVID-19) pandemic has been a constant in everyone’s lives for almost the past three years now and has embedded itself into basically every part of global society and norms. The main areas where this is evident are in the major disruptions in the economic, social, and public health sectors of the world. There is one other area that has been affected by this prolonged pandemic in a multitude of ways, the environment. Our environment, both globally and regionally, has seen both positive and negative effects throughout the COVID-19 pandemic in a variety of different areas. …

Analysis Of The Headspace Gases Formed From The Fermentation Of Barley, Ken Overway, Cassie Taylor

Chemistry Faculty Scholarship

Volatile compounds are compounds that can exist in a gaseous state at room temperature. These compounds contribute to the aromas that are associated with mixtures. The analysis of these gases can be completed using a gas chromatograph to provide a sort of fingerprint identification. The analysis of the volatile compounds for barley fermentation samples was completed by collecting the gas above the fermenting solution, the headspace gas, and injecting this gas into the gas chromatograph. These fermentation samples showed predominantly the formation of carbon dioxide for a significant length of time before finally ethanol was detected. A subsequent of the …

Extraction & Purification Of Ppix Using Hplc & Fplc, Ken Overway, Grace Rilee

Chemistry Faculty Scholarship

Porphyrins, an organic molecule, are a possible sensitizer for dye-sensitized solar cells (DSSC) because of their strong absorption in the visible spectrum. One naturally occurring porphyrin is protoporphyrin IX (PPIX), which can be found in brown eggshells. There are two reasons why PPIX is the ideal sensitizer. (1) The absorbance spectrum of PPIX can be modified by changing ring substituents, thus tuning the absorbance to the solar spectrum. (2) PPIX allows for direct attachment to the DSSC due to the carboxylic acid substituents on PPIX and the TiO₂ of the DSSC. The HPLC was used to develop a chromatographic …

Cooperative Allosterism In Avidin And Streptavidin Upon Biotin Binding As Observed By Changes In Intrinsic Fluorescence, Alycia Murphy

Celebration of Scholarship 2022

Avidin is a homotetrameric protein known for its high binding affinity and specificity for biotin which gives it great functionality in many biotech applications. Prior research on the bacterial analog, streptavidin found cooperative allosterism exhibited in the binding process. This research was aimed at investigating whether this same cooperative allosterism accompanies the binding of biotin to avidin. This work measured intrinsic tryptophan fluorescence as biotin was titrated into avidin. A blueshift in the wavelength of maximum fluorescence as well as quenching of the overall fluorescence intensity, similar to the streptavidin was observed. The saturation point for 335 nm emission (tryptophans …

A Damaged Reputation: Nuclear Depictions In Entertainment Media, Alexander Cannon

Chemistry & Biochemistry Student Scholarship

This paper, originally written for Dr. Adamus Liotta in an honors chemistry class, explores the possibility of a significant influence over public common sense found in the depictions of entertainment media. Through careful analysis and interpretation of Godzilla, The Simpsons, Fallout, and Call of Duty, this paper finds a synergy throughout this diverse range of audience, medium and historical origin, which culminates in an effect much greater than the sum of its parts. This effect frames nuclear science, of any kind, in a hyperbolically catastrophic and horrific light, reinforcing an excessively cautious, pessimistic public perspective on nuclear technology …

The Analysis And Remediation Of Excess Fluoride In Drinking Water In Isle Of Wight County, Va, Kaleigh Beale

Longwood Senior Theses

Excess fluoride in drinking water can cause fluorosis or brown and yellow staining of the enamel of teeth. In extreme cases, severe damage to teeth and bone structure can develop. In 1993, the World Health Organization set a limit of 1.5 ppm as acceptable for drinking water; however, in Isle of Wight County, Virginia, recent water quality reports detected levels of fluoride as high as 4 ppm. The purpose of this study was to investigate several detection and remediation methods of fluoride in drinking water. Detection methods included an ion selective electrode (ISE), dye-based colorimetric methods, and an at-home testing …

Synthesis And Evaluation Of Gallate Esters As Alternatives To Traditional Parabens, Marcia Reeves

Longwood Senior Theses

Parabens are esters of p-hydroxybenzoates that are commonly found in everyday consumer products as well as pharmaceuticals. They are often used in commercial products to prevent bacterial growth as well as to provide extended shelf life, but they have been shown to activate estrogen receptors in vivo, a contributing factor in human breast cancer proliferation. Our lab has previously generated a multitude of paraben derivatives that do not exhibit estrogenic activity. Many of these derivatives may have other safety concerns, but gallate esters appear to have the least hazardous properties. The estrogenic, antimicrobial, and antioxidant properties of the gallate ester …

Quantification Of Silver Nanoparticle Interactions With Yeast Saccharomyces Cerevisiae Studied Using Single-Cell Icp-Ms, Lindsey Rasmussen, Honglan Shi, Wenyan Liu, Katie Shannon

Chemistry Faculty Research & Creative Works

Silver nanoparticles (AgNPs) have been used in many fields due to their anticancer, antimicrobial, and antiviral potential. Single-cell ICP-MS (SC-ICP-MS) is an emerging technology that allows for the rapid characterization and quantification of a metal analyte across a cell population in a single analysis. In this study, a new rapid and sensitive SC-ICP-MS method was developed to quantitatively study the interactions of AgNPs with yeast Saccharomyces cerevisiae. The method can quantify the cell concentration, silver concentration per cell, and profile the nanoparticle distribution in a yeast cell population. AgNP dosing time, concentration, and AgNP size were quantitatively evaluated for their …

Unraveling Molecular Mechanisms Of Antibiotic Resistance Through Multiscale Simulations And Explainable Machine Learning, Zilin Song

Chemistry Theses and Dissertations

Pathogen resistance to β-lactam antibiotics compromises effective treatments of superbug infections. One major source of β-lactam resistance is the bacterial production of β-lactamases, which could effectively hydrolyze β-lactam drugs. In this thesis, the hydrolysis of various β-lactam antibiotics by class A serine-based β-lactamases (ASβLs) were investigated using hybrid Quantum Mechanical / Molecular Mechanical (QM/MM) minimum energy pathway (MEP) calculations and explainable machine learning (ML) approaches. The TEM-1/benzylpenicillin acylation reaction with QM/MM chain-of-states reaction pathways was firstly revisited. I proposed two decomposition methods for energy contribution analysis based on perturbing ML regression models. Both methods were shown to be model implementation …

In Situ Recording Of Mars Soundscape, S. Maurice, B. Chide, N. Murdoch, R. D. Lorenz, D. Mimoun, R. C. Wiens, A. Stott, X. Jacob, T. Bertrand, F. Montmessin, N. L. Lanza, C. Alvarez-Llamas, Stanley M. Angel, M. Aung, J. Balaram, O. Beyssac, A. Cousin, G. Delory, O. Forni, T. Fouchet, Et. Al.

Faculty Publications

Before the Perseverance rover landing, the acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller at the point where molecular viscosity converts kinetic energy into heat1, (2) the speed of sound varies at the surface with frequency^2,3 and (3) high-frequency waves are strongly attenuated with distance in CO₂ (refs.^2,3,4). However, theoretical models were uncertain because of a lack of experimental data at low pressure and the difficulty to characterize turbulence or attenuation in a closed environment. Here, using Perseverance …

Faith Jacobsen - Sabbatical Spring 2022, Faith Jacobsen

Sabbatical Projects

My sabbatical had two main parts:

1. Analysis of data collected the previous semesters and writing up a research paper about student learning gains from making video quizzes of lab techniques. This work was published in the Journal of Chemical Education in Spring 2023.

https://pubs.acs.org/doi/10.1021/acs.jchemed.2c00867

2. Creation of an online platform to learn organic spectroscopy using the open source software Twinery.

Microwave-Assisted Synthesis Of Quinoxaline Derivatives, Eric Horsting

Honors Theses

Quinoxaline and its derivatives have been studied extensively for their relevant biological activity and transition metal selectivity. These compounds are commonly used for their antimicrobial, antifungal, antiparasitic activity, and relevance in the treatment of metabolic diseases [6]. More recently, quinoxaline’s ability to inhibit gram-positive bacterial growth has been found especially in oxygen- containing compounds, yielding promising candidates to prevent cancerous tumor growth [5]. The breadth of quinoxaline makes it a valuable tool within the research community However, its synthesis requires complex solvents, extended reaction times, and often produces a low yield. By using a microwave-assisted synthesis, this novel methodology offers …