Physical Sciences and Mathematics Commons^™

Mapping Roles Of Active Site Residues In The Acceptor Site Of The Pa3944 Gcn5-Related N-Acetyltransferase Enzyme, Cillian Variot, Daniel Capule, Xhulio Arolli, Jackson Baumgartner, Cory T. Reidl, Charles Houseman, Miguel Ballicora, Daniel P. Becker Ph.D., Misty L. Kuhn

Chemistry: Faculty Publications and Other Works

An increased understanding of how the acceptor site in Gcn5-related N-acetyltransferase (GNAT) enzymes recognizes various substrates provides important clues for GNAT functional annotation and their use as chemical tools. In this study, we explored how the PA3944 enzyme from Pseudomonas aeruginosa recognizes three different acceptor substrates, including aspartame, NANMO, and polymyxin B, and identified acceptor residues that are critical for substrate specificity. To achieve this, we performed a series of molecular docking simulations and tested methods to identify acceptor substrate binding modes that are catalytically relevant. We found that traditional selection of best docking poses by lowest S scores …

Aerosol Mutagenicity In San Bernardino, California Via Bacterial Fluctuation Tests, Sean Murphy

Electronic Theses, Projects, and Dissertations

San Bernardino, California’s poor air quality is a health risk to its population with some of the highest concentrations of ozone and aerosol in the United States. Aerosols are solid or liquid particles suspended in the air. Smaller aerosol particles are the most harmful as they are more likely to penetrate further into the respiratory system. These aerosols can cause respiratory issues and contain toxic compounds. One measure of aerosol toxicity is to study the mutagenicity of the aerosol. To study the mutagenicity of aerosol samples collected in San Bernardino in 2022, fluctuation tests (based on the Ames test for …

Advances In One-Electron Self-Interaction-Correction Methods For Accurate And Efficient Self-Interaction-Free Density Functional Calculations, Selim Romero

Open Access Theses & Dissertations

Density functional theory (DFT) is a widely used computational method for studying electronic structures of atoms, molecules, and solids. It provides an exact theory for obtaining ground state energy from the ground state density. However, since the exact exchange-correlation functional remains unknown, approximate exchange-correlation functionals called approximate density approximations (DFAs) are used. The foundation of many DFAs is the local spin density approximation (LSDA). It serves as the starting point for constructing various DFAs. However, DFAs are prone to self-interaction errors (SIE) due to the improper cancellation of the approximate exchange energy and the Coulomb energy. This issue impacts the …

Outgassing Behavior And Heat Treatment Optimization Of Jsc-1a Lunar Regolith Simulant, Ryan P. Wilkerson, Mihail P. Petkov, Gerald E. Voecks, Catherine S. Lynch, Holly S. Shulman, Santhoshkumar Sundaramoorthy, Amitava Choudhury, Douglas L. Rickman, Michael R. Effinger

Chemistry Faculty Research & Creative Works

As NASA Strives towards a Long Duration Presence on the Moon, It Has Become Increasingly Important to Learn How to Better Utilize Resources from the Lunar Surface for Everything from Habitats, Vehicle Infrastructure, and Chemical Extraction. to that End, a Variety of Lunar Simulants Have Been Sourced from Terrestrially Available Volcanic Minerals and Glass as Apollo Regolith is Unavailable for Experimentation Needing Large Masses. However, While Mineralogy and Chemical Composition Can Approach that of Lunar Material in These Simulants, There Are Still Distinct Non-Lunar Phases Such as Hydrates, Carbonates, Sulfates, and Clays that Can Cause Simulants to Behave Distinctly Non-Lunar …

Addressing Learning Gaps In Acid-Base Chemistry Using Novel Three-Dimensional Models With Learning Module, Gabrielle Marie Grimes

Theses and Dissertations

Teaching scientific concepts is very complex and includes the discussion and use of different models that support students’ understanding of particle-level interactions and behavior of chemical phenomena. The presented research describes the development of three-dimensional acid-base models and an accompanying learning module to support students’ understanding of the autoionization of water, acidic strength, pH, and Ka in aqueous acid-base chemistry. The model set includes acid and base models embedded with magnets and removable hydrogen atoms or hydroxide groups to model particle-level interactions. The magnetic models allow students to investigate particle-level processes with student-built models of aqueous acid and base systems. …

Research Instrumentation Center (Ric), Ryan Hilger, Purdue University Office Of Research

University Research Core Facility Boilerplate Descriptions

No abstract provided.

A Low Cost, Compact Electrochemical Analyzer Based On An Open-Source Microcontroller, Michael Kofi Darko Addo

Electronic Theses and Dissertations

Compared to other instruments for chemical analyses, electrochemical analyzers are relatively simple, inexpensive, easy to miniaturize and require little-to-no maintenance. However, like all commercially available instruments, commercial electrochemical analyzers like potentiostats primarily operate as black boxes with manufacturers providing little or no information about internal circuitry and programming. This practice can limit a researcher’s ability to develop new techniques or adapt an instrument for applications outside its typical use. In contrast, creators of open-source instruments release all the necessary information for reproduction of the hardware and software – minimizing such barriers to innovation in chemical analyses. Here, we report a …

Extraction, Purification, And Characterization Of Potential Bioactive Compounds Produced By Janthinobacterium Lividum Tajx1901, Andy Elorm Agbakpo

Electronic Theses and Dissertations

Underexplored environments such as soil samples continue to be an untapped source of bacterial strains with great potential to produce secondary metabolites for medicinal applications. As a result, these microorganisms represent a broad and yet unknown reservoir of new strains capable of producing these novel compounds. The current research primarily seeks to perform the isolation, purification, and characterization of secondary metabolites from a soil bacterium (Janthinobacterium lividum TAJX1901). The isolated soil bacterium was successfully cultured on rich media agar plates, followed by extraction using methanol and chloroform. The purification methods utilized include flash column chromatography, preparative thin-layer chromatography, and …

Isolation And Structural Determination Of Bioactive Metabolites From The Soil Bacterium, Arthrobacter Sp. Tajx1902, Amonah Arije

Electronic Theses and Dissertations

As antimicrobial resistance persistently disrupts the treatment of microbial infection, natural product chemistry has played a significant role in identifying novel drugs with novel modes of action critical to getting ahead of resistance. The primary goal of this project is to extract and identify potential novel antimicrobial natural products produced by Arthrobacter sp. Although underexplored, Arthrobacter sps. have been known to produce bioactive compounds with versatility; one such is a depsipeptide with quorum-sensing inhibitory activity.¹ In this research, an Arthrobacter sp. TAJX1902, isolated from a soil sample, showed inhibitory activity against a filamentous indicator bacterium and a violacein-producing Janthinobacterium …

Intra-Gendered Perceptions And Adoption Of Climate-Smart Agriculture: Evidence From Smallholder Farmers In The Upper East Region Of Ghana, Kwabena Antwi, Philip Antwi-Agyei

Student Publications

Climate-smart agriculture (CSA) remains a key strategy for sustaining agricultural systems and achieving food security and nutrition. Despite this, uncertainty remains on how intra-gendered dynamics influence its adoption in dryland farming systems. This study implements both quantitative and qualitative approaches including household surveys, key informant interviews, and focus group discussions to explore how intra-gender dynamics shape the perceptions and adoption of climate-smart agriculture in three selected communities (Katanga, Dakio, and Zonno) in the Bolgatanga East District of the Upper East Region of Ghana. Specifically, the study answers the following research questions: (i) What is the degree of change in rainfall …

Indium Doped Zinc Stannate-Pdms Based Piezoelectric Generator For Harvesting Mechanical Energy And Sensory Application, Tamanna Zakia

Theses and Dissertations

Piezoelectric materials are comparatively new among other alternative energy sources. Harvesting waste mechanical energy through these materials can be a potential solution of the increasing energy demand. In response to applied mechanical stress, piezoelectric materials accumulate electric charges on their surface. Upon connecting with a circuit, accumulated charges can flow and generate electricity. Based on this hypothesis piezoelectric nano-generator has been fabricated. Binary semiconducting oxides such as ZnO, TiO2 and SnO2 have attracted immense interest as they have unique properties of electron mobility. However, there is always a need for specially designed semiconductors to better match with the properties. This …

Integrating Sensor Development, Risk Assessment, And Community Engagement To Support Environmental Justice In The Rural Community Of El Tiple, Colombia, David Bahamon Pinzon

All Dissertations

In Colombia, ethnic communities have traditionally been responsible stewards of natural resources. They recognize the importance of these resources for their livelihood, as well as their ancestral and cultural heritage. El Tiple, a rural Afro-Colombian community, has been affected by the incursion of private corporations that promoted the expansion of sugarcane monocrops in their territory. Since the introduction of the monoculture industry, local freshwater sources have been depleted due to intensive water use for irrigation of the sugarcane crops. Additionally, the intensive usage of agrochemicals has been linked with loss of native flora, damages to family farms, and pollution of …

Studying The Stability Of Collagen/Heparin Coatings To Be Used In Cell Therapy Applications, Gavin Mussino

Biological Sciences Undergraduate Honors Theses

This honors thesis aims to investigate the reusability and performance of cell coatings for cell therapy applications. Cell therapy, which involves the use of human cells to repair or replace damaged tissues, holds immense potential for medical advancements. However, ensuring the survival and functionality of transplanted cells remains a significant challenge. We focused on studying the effectiveness of coatings applied to cells for improved cell growth and viability. The research project involved the preparation of the coatings using a layer-by-layer method and the subsequent seeding of cells. The coated cells were then subjected to a series of experiments to assess …

Dinitrogen Functionalization Using A Molybdenum Atom: Bridging The Gap Between Small And Coordination Complexes Via Quantum Mechanical Methods, Maria Virginia White

Doctoral Dissertations

Chemistry devotes a significant amount of its research to understanding small molecule activation from an electronic structure perspective to help with the investigation of the reaction pathways of catalytically active substances that can promote biomimetic catalysis. A large portion of the energy used annually in our planet is used for the artificial nitrogen fixation (Haber-Bosch process), which renders dinitrogen activation a subject of study. Molybdenum, a fourth row transitional metal, has demonstrated its effectiveness as an essential component of the dinitrogen reduction catalytic process. To better understand the multiple dinitrogen molybdenum binding modes, the work described herein combines wave function …

Composite And Polymer Formulation Employing Sulfur And Bio-Olefin Feedstocks, Claudia V. Lopez

All Dissertations

Environmental sustainability represents a challenge for society since industrial growth has a direct impact on natural resources and waste production. New technologies that effectively incorporate waste into renewable resources are critical to the development of a sustainable and circular economy. The manufacturing of structural materials like Portland cement (OPC) is responsible for >8% of the global anthropogenic emissions of carbon dioxide, with ~ 1 kg of CO₂ released to the atmosphere for every kilogram of OPC produced. For instance, the development of sustainable structural materials is a key factor to reduce the greenhouse emissions and to attenuate the climate …

Differential Membrane Binding Of Α/Β-Peptide Foldamers: Implications For Cellular Delivery And Mitochondrial Targeting, Tzong-Hsien Lee, James W. Checco, Tess Malcolm, Chelcie H. Eller, Ronald T. Raines, Samuel H. Gellman, Erinna F. Lee, W. Douglas Fairlie, Marie-Isabel Aguilar

Chemistry Department: Faculty Publications

The intrinsic pathway of apoptosis is regulated by the Bcl-2 family of proteins. Inhibition of the anti-apoptotic members represents a strategy to induce apoptotic cell death in cancer cells. We have measured the membrane binding properties of a series of peptides, including modified α/β-peptides, designed to exhibit enhanced membrane permeability to allow cell entry and improved access for engagement of Bcl-2 family members. The peptide cargo is based on the pro-apoptotic protein Bim, which interacts with all anti-apoptotic proteins to initiate apoptosis. The α/β-peptides contained cyclic β-amino acid residues designed to increase their stability and membrane-permeability. Dual polarisation interferometry was …

Band Gap Engineering In Ternary Oxides And Sulfides: A Route To New Photoelectrodes For Solar Energy Conversion, Fahad Ibrahim Danladi

Chemistry & Biochemistry Dissertations

In recent years, there has been a growing interest in semiconductor photoelectrodes that can effectively split water into hydrogen and oxygen using sunlight. However, there is currently no known material that is efficient enough to be used for commercial purposes. Photoelectrodes currently have an efficiency of less than 10% in converting water under visible light irradiation. There is a need to develop an efficient semiconductor photoelectrode for photoelectrochemical water splitting that is both chemically stable and affordable, composed of earth-abundant elements and capable of operating under visible light. Metal oxides are considered promising photoelectrode materials due to their low cost, …

Reactive Atmosphere Pyrolysis(Rap) Of Silicon Carbo Nitride (Sicn), Akshada Bharat Hande

Chemistry & Biochemistry Theses

Polymer Derived Ceramics (PDCs) are synthesized by converting liquid polymer precursors into ceramics through controlled pyrolysis. This study focuses on silicon carbonitride (SiCN) ceramics obtained from Ceraset Polysilazane (Durazane1800) precursor. The influence of pyrolysis atmospheres, including inert (Ar, N2) and reactive (H2) environments, on the thermal conversion of Durazane1800 into SiCN ceramics is investigated. The resulting ceramics' chemical variations are explored through phase analysis using X-ray diffraction (XRD), Raman spectroscopy, and thermogravimetric analysis (TGA). Notably, the impact of hydrogen versus nitrogen atmospheres on the conversion process is analyzed, shedding light on their distinct contributions to the composition and properties of …

Identification Of Acidic Residues In Proteins By Selective Chemical Labeling And Tandem Mass Spectrometry, Fnu Ashima

Chemistry & Biochemistry Theses

Proteins play important role in carrying out a wide range of cellular activities. They are subjected to various post-translational modifications (PTMs) by the addition of functional groups such as acetyl, phosphoryl, and methyl which leads to changes in their biological functions, localization, activity, and structure. The growth of MS technology has immensely facilitated the identification of PTMs comprehensively. This dissertation focuses on mapping these changes using covalent labeling techniques by tagging carboxylic acid residues, which undergo various kinds of PTMs. The second chapter focuses on the methods designed for Affinity Purification Mass Spectrometry (AP-MS) chemical cross-linking (CXL) of protein complexes. …

Development And Applications Of Novel And Practical Fluorination Reagents., Yuhao Yang

Electronic Theses and Dissertations

The fluorine (F) atom has distinctive properties such as the highest electronegativity, small size, low polarizability, and strong C–F bond strength. Not surprisingly, fluorinated organic compounds have garnered significant attention in the pharmaceutical, agrochemical, and material fields. Since organofluorides are very rare in nature, we need fluorination reagents to help us transfer fluorine into the organic molecules. In past decades, a vast number of fluorination reagents have been developed and many of them are commercially available now. However, there is still much room for the improvement of these reagents. Our target is to develop novel and practical fluorination reagents to …

New Methodologies For Sustainable Organic Synthesis In Water., Sudripet Sharma

Electronic Theses and Dissertations

Water is stable, benign, and green solvent. Its usage as a solvent in organic synthesis is significantly enhanced by micellar catalysis. However, replacing water as a reaction medium in organic synthesis is not sufficient to meet the sustainability challenges—excessive organic solvents are still required for product isolation and purification. Notably, solvents used in syntheses contribute to more than 80% of waste generation. In addition to solvents, the use of palladium in large amounts is also a problem for the future as it is a precious, low-abundance metal, and its supply is dwindling. Therefore, this dissertation highlights the various sustainable protocols …

Towards Deposition Of Iron & Nickel Onto Cadmium Selenide/Cadmium Sulfide Nanorods, Rajib Nath

Masters Theses & Specialist Projects

Metal-semiconductor hybrids have been studied extensively as photocatalysts for the watersplitting reaction to generate hydrogen gas and oxygen gas to use as a renewable energy source. The semiconductor component converts light into electrochemical energy, while the metal component provides a site for chemical reactions with water. Here, the choice of metal can have a significant impact on the efficiency of the catalyst. Platinum efficiently catalyzes the watersplitting reaction and is therefore commonly used in metal-semiconductor hybrids to generate hydrogen. Platinum is very expensive, which motivates research into improving less costly metals like iron or nickel that do not have nearly …

Clickable Lipid Precursors As Chemical Tools For Imaging And Tracking Lipids, Christelle Anne Fernandez Ancajas

Doctoral Dissertations

The regulation of lipid metabolism is crucial for maintaining the human body, as disruptions in lipid homeostasis have drastic implications. While lipids are known for their roles as energy stores as well as for cellular compartmentalization, certain lipid classes can serve as signaling agents that govern cellular behavior and physiology or as biomarkers whose concentration and spatial organization impacts cell fate. Thus, dysregulation in these processes coincide with a variety of diseases and cancers. However, the ability to track lipids has been a long-standing challenge in the area of chemical biology since lipids are chemically diverse and undergo continuous interconversion …

Dinitroxides In Rapid Scan Electron Paramagnetic Resonance Imaging, Lukas B. Woodcock

Electronic Theses and Dissertations

Local tissue physiology is an important parameter in understanding disease behavior. Rapid Scan (RS) electron paramagnetic resonance (EPR) offers a unique, non-invasive tool for investigation of these so-called microenvironments through EPR Imaging (EPRI). Research into advancement of EPRI falls into many categories. Not least among those are advances in instrumentation and methodology. Presented here are updates to a benchtop EPRI instrument operating at 1 GHz targeted at pre-clinical EPRI applications. Newly developed methods for reducing RS-EPR background through inversion of the magnetic field are also demonstrated. EPR applications are limited in native biological systems due to the miniscule concentration of …

Long Non-Coding Rnas In Inflammation, Macrophage Activation, And Inflammatory Human Diseases, Avisankar Chini

Chemistry & Biochemistry Dissertations

Inflammation and immune signaling is central to infection and diseases. Growing evidence suggests that along with protein coding genes, long non-coding RNAs (lncRNAs) play a critical role in disease onset, combat, and recovery against pathogen, damaged and self-altered cells. Our lab has been extensively studying the role of lncRNA HOTAIR (HOX transcript antisense intergenic RNA) in gene regulation and epigenetics, and eventually discovered its hidden function regulating inflammation and immune signaling in macrophage, a major type of cell involved in immunity. Previous scholars in our lab have successfully demonstrated lncRNA HOTAIR’s regulatory molecular mechanism elucidating its specific role in cellular …

Implementation Of Reading Interventions In Introductory Chemistry And Its Impact On Student Performance, Fatoumata Diawara

Theses and Dissertations

ABSTRACT

IMPLEMENTATION OF READING INTERVENTIONS IN INTRODUCTORY CHEMISTRY AND ITS IMPACT ON STUDENT PERFORMANCE

by

Fatoumata Diawara

University of Wisconsin Milwaukee, 2023Under the Supervision of Professor Anja Blecking, PhD

Research studies conducted in disciplinary literacy in the last 15 years have shown that students' reading comprehension is as much a predictor of student success in college science courses as in students' math skills (O’Reilly & McNamara, 2007). However, college STEM programs often focus solely on teaching STEM content, assuming students' reading comprehension skills have been developed in high school. Thus, only a few examples of reading interventions for students in …

Manufacturing Of A Flexible Piezoelectric Nanogenerator By Functionalizing Polyvinylidene Fluoride With Lithium Tantalate And Multiwalled Carbon Nanotubes For Energy Harvesting And Sensing Applications, Islam Uddin Shipu

Theses and Dissertations

Mechanical energy is one of the readily accessible green energy sources that could be employed to meet the small-scale energy requirement. In order to capture mechanical energy, power the next generation of electronic gadgets, and health monitoring flexible piezoelectric nanogenerators made of light weight polymers and carbon nanotubes have drawn a lot of attention. Lithium tantalate (LiTaO3), a ferroelectric substance, was prepared here and utilized to create a flexible piezoelectric nanogenerator (FPNG). A compact piezoelectric nanogenerator that successfully transfers mechanical energy into electricity was then created using lightweight polyvinylidene fluoride (PVDF), multi-walled carbon nanotube (MWCNT), and LiTaO3 nanoparticles. To create …

Organocatalyzed Four-Component On-Water Green Synthesis Of Spiroindolinpyranopyrazole, Tanzida Zubair

Theses and Dissertations

Although many synthetic and natural pharmaceuticals and drug-like compounds contain spiro center(s) in their structures, the synthesis of spiro centers is seen to be an exciting and difficult area of research. The synthesis of spiro compounds and their derivatives was carried out using a four-component process that included reagents like hydrazine hydrate, isatin, malononitrile, and an active methylene compound like ethyl acetoacetate. Microwave irradiation was used in a short time range (5 – 30 min) and moderate temperature (80°C), with water as a solvent, and N, N-Diisopropylethylamine (DIPEA) as a catalyst to give high yield of products. Our process complies …

Poly(Ionic Liquid)S For Magnetic, Ionic, And Electrical Stimuli-Responsive Applications, Kayla Ann Foley

Graduate Theses and Dissertations

Poly(ionic liquid)s (PILs) are a fascinating subclass of strong polyelectrolytes formed from polymerizable ionic liquids. As a result of their unique properties and counterion exchangeability, PILs can exhibit conformation structure or material property changes in response to external stimuli such as changes in pH/ionic environment, magnetic fields, and electric potentials. In Chapter 1, a comprehensive review of PILs design as well as their stimuli-responsive behavior is provided. Additional motivation for each dissertation chapter is also discussed. In Chapter 2, magnetically responsive PILs (MPILs) are developed from complexing paramagnetic salts with a random PIL copolymer containing a metal-coordinating co-monomer, acrylamide. A …

Atom Economical Reactions Of Terpenoids And Post-Consumer Plastics With Sulfur, Charini Maladeniya

All Dissertations

The production of Ordinary Portland Cement (OPC) and its uses have a complicated environmental impact, which is influenced by infrastructure development and building operations as well as CO₂ emissions, which account for 7% of all worldwide CO₂ emissions. Due to the increasing population, production is still ongoing. The search for cement and construction materials produced with zero to low CO₂ emissions is therefore continuous. Finding recyclable, CO₂ gas-free biocomposites with high sulfur content that can rival the mechanical properties of popular building supplies like Portland cement is the primary objective of the research discussed in this …