Chemistry Commons^™

Energy Requirements For Abiotic Production Of Phosphorous Compounds At The Ice-Schreibersite Interface, Lindsay M. Hicks

Symposium of Student Scholars

Energy Requirements for Abiotic Production of Phosphorous Compounds at the

Ice-Schreibersite Interface

The Abbott-Lyon Lab is investigating the chemistry at the interface of simple ices and a meteoritic mineral analogue. Phosphorous is a key component of numerous biomolecules necessary for life. Lack of an abundance of biologically accessible mineral sources of phosphates on Earth, termed “The Phosphorous Problem,” has led some origin-of-life scientists to look to extraterrestrial sources like meteoritic metal phosphides as possible sources of available phosphates. Schreibersite (Fe₂NiP) is a common mineral in iron meteorites and a plausible source of biologically accessible phosphorous. This study will …

Using Eye-Tracking Data To Determine What Biochemistry Students Attend To When Completing A Revised Three-Dimensional Modeling Activity, Hailey Knoeferl

Symposium of Student Scholars

In biochemistry, three-dimensional models are being used to help students comprehend advanced topics within the subject. Because a greater cognitive load is often related to three-dimensional models, learning what raises the cognitive load is critical. From there, measures can be taken to help lower the cognitive load and make the material easier for students to understand. To understand cognitive load in relation to models, students were presented with three-dimensional serine protease models and their substrates and asked to match the clear surface plate to the backbone, and then the substrate to the surface plate. On the substrates, students were asked …

Investigation Of Chemistry At Ice-Mineral Interfaces Of Phosphorus-Containing Meteorites Analogues, Kimberly Meyberg

Symposium of Student Scholars

The search for life outside of Earth has raised questions about how life began have intrigued origin-of-life researchers, such as the incorporation of phosphorus into biomolecules. Phosphorus exists on Earth mostly as phosphate, PO₄^3-, which is insoluble and unreactive in the geochemical conditions of the early Earth. The challenge of incorporating phosphorus into biomolecules is known as the “phosphorus problem,” prompting investigations of reactive phosphorus species delivered to the prebiotic Earth. Phosphorus-laden meteorites delivered schreibersite (Fe,Ni)₃P, a possible mineral source of phosphorus recognized for its redox chemistry potential and observed reactivity with aqueous …

Chemical Industrial Safety And Environmental Considerations, James Stewart

Symposium of Student Scholars

Chemical Industrial Safety and Environmental Considerations

James Stewart

Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, GA, 30144

Workplace safety, particularly in the chemical manufacturing and treatment industries, is always at the core of any competent business strategy of any modern industrially- or manufacturing-focused company. Due to the inherent and sometimes readily apparent nature of chemical hazards, safety in these industries has been, by necessity, a practical consideration since their inception. However, only relatively recently has it developed into a significant philosophical focus of businesses, regulatory agencies such as OSHA, and associated non-regulatory bodies such as the U.S. Chemical …

Electrochemical And Spectroscopic Characterization Of Cerium Salts And Nanoceria Material, Emily Velarde, Wei Zhou

Symposium of Student Scholars

The nanoscale form of cerium oxide, nanoceria (nano-CeO_x), has drawn great attention in recent years in electrochemical, nanomaterial research and medicinal studies due to its antibacterial properties, UV absorption, and its biochemical function as possible radical scavenger. Many new synthesis methods have achieved uniform and biocompatible nanoceria particles, and our lab has created cerium oxide particles that shows UV/Vis. absorption and X-ray patterns similar to the commercial nanoceria and nanoceria made in other research laboratories with novel synthetic methods.

This study focuses on charactering and comparing electrochemical properties of cerium inorganic salts and synthesized nanoceria. Preliminary results …

Bioanalytical Determination Of Glucose Concentration In Sports Drinks Using Uv/Vis Spectroscopy, Laney Hedgeman, Brianna Bond

Symposium of Student Scholars

Abstract

The purpose of our project is to indirectly monitor the enzymatic activity of glucose oxidase as it reacts with the glucose present in sports drinks through the quantitative analysis of the generated ferricyanide. As glucose oxidase catalyzes the oxidation of beta-D-glucose in the presence of oxygen, D-glucono-1,5-lactone is produced along with hydrogen peroxide. The hydrogen peroxide is used in a subsequent reaction with ferrocyanide catalyzed by horse radish peroxidase to produce water and the chromophore ferricyanide. This compound absorbs in the ultraviolet/visible spectrum at 420 nm, which can be quickly measured using Ultraviolet/Visible Spectroscopy. Since the molar ratio of …

From Disease Description And Gene Discovery To Functional Cell Pathway: A Decade-Long Journey For Tmco1, Helen Batchelor-Regan, Baozhong Xin, Aimin Zhou, Heng Wang

Chemistry Faculty Publications

A decade has passed since transmembrane coiled-coil domains 1 (TMCO1) defect syndrome was identified in 11 undiagnosed patients within the Old Order Amish of Northeastern Ohio-a disorder characterized by a distinctive craniofacial dysmorphism, skeletal anomalies and global developmental delay. Twenty seven patients, from diverse ethnic groups, have been reported with pathogenic TMCO1 variants now recognized to cause cerebrofaciothoracic dysplasia (CFTD). The implication of previously uncharacterized TMCO1 within disease has instigated a 10-year journey to understand the function of TMCO1 protein in Ca2+ homeostasis. TMCO1 is an ER Ca2+ leak channel which facilitates Ca2+ leak upon ER "overload" through the novel …

Keap1 Cancer Mutants: A Large-Scale Molecular Dynamics Study Of Protein Stability., Carter J Wilson, Megan Chang, Mikko Karttunen, Wing-Yiu Choy

Chemistry Publications

We have performed 280 μs of unbiased molecular dynamics (MD) simulations to investigate the effects of 12 different cancer mutations on Kelch-like ECH-associated protein 1 (KEAP1) (G333C, G350S, G364C, G379D, R413L, R415G, A427V, G430C, R470C, R470H, R470S and G476R), one of the frequently mutated proteins in lung cancer. The aim was to provide structural insight into the effects of these mutants, including a new class of ANCHOR (additionally NRF2-complexed hypomorph) mutant variants. Our work provides additional insight into the structural dynamics of mutants that could not be analyzed experimentally, painting a more complete picture of their mutagenic effects. Notably, blade-wise …

Theranostic Applications Of Sirna Bioconjugates In Cancer Detection And Treatment, Sunil S. Shah

Seton Hall University Dissertations and Theses (ETDs)

Abstract

The emerging field of RNA nanotechnology has led to rapid advances in the applications of RNA in chemical biology, medicinal chemistry, and biotechnology. At the forefront of its utility is the ability to self-assemble multiple siRNAs into nanostructure formulations capable of targeting selected oncogenes and potentiating the gene therapy of malignant tumors. Self-assembled siRNA integrates multiple siRNAs within a single molecular platform for silencing multiple oncogenic mRNA targets with high precision and efficacy to potentially induce cancer cell apoptosis through the RNA interference (RNAi) pathway. Furthermore, the conjugation of siRNA self-assemblies with bio-active probes results in multi-functional theranostic (therapy+diagnostic) …

Using Chemical Speciation Modelling To Discuss Variations In Patch Test Reactions To Different Aluminium And Chromium Salts, Saman Nikpour, Yolanda S. Hedberg

Chemistry Publications

Background: Allergic contact dermatitis to metals is diagnosed by applying a metal salt in a patch test. The bioavailability of the metal salt might depend on the choice of metal salt, the concentration, sweat composition, and pH.

Objectives: The main purpose of this study was to apply chemical speciation modelling, which is based on experimentally derived input data and calculates the concentrations of chemical forms (species) in solutions, to reproduce and discuss clinical patch test results of aluminium and chromium.

Methods: Joint Expert Speciation System (JESS), Hydra/Medusa, and Visual Minteq were employed to study the bioavailable fraction and chemical form …

Host–Guest Interactions In A Metal–Organic Framework Isoreticular Series For Molecular Photocatalytic Co2 Reduction, Philip M. Stanley, Johanna Haimerl, Christopher Thomas, Alexander Urstoeger, Michael Schuster Prof. Dr., Natalia B. Shustova Prof. Dr., Angela Casini Prof. Dr., Bernhard Rieger Prof. Dr., Julien Warnan Dr., Roland A. Fischer Prof. Dr.

Faculty Publications

A strategy to improve homogeneous molecular catalyst stability, efficiency, and selectivity is the immobilization on supporting surfaces or within host matrices. Herein, we examine the co-immobilization of a CO2 reduction catalyst [ReBr(CO)3(4,4′-dcbpy)] and a photosensitizer [Ru(bpy)2(5,5′-dcbpy)]Cl2 using the isoreticular series of metal–organic frameworks (MOFs) UiO-66, -67, and -68. Specific host pore size choice enables distinct catalyst and photosensitizer spatial location—either at the outer MOF particle surface or inside the MOF cavities—affecting catalyst stability, electronic communication between reaction center and photosensitizer, and consequently the apparent catalytic rates. These results allow for a rational understanding of an optimized supramolecular layout of catalyst, …

Methodology Utilizing Triphosgene To Promote Cyclization Of Epoxy Ketones To Pyranoside Derivatives Via Proposed Epoxonium Ions, Isaac Camargo Dos Reis

LSU Master's Theses

The development of new methodologies in organic chemistry is of great importance. In fact, the discovery and creation of new reactions frequently uncovers new chemical reactivities and creates new areas of chemistry. The purpose of this thesis is to present the development of new synthetic reactions that were discovered through previous findings. Additionally, the main theme of this work relies on the intermediacy of a cationic reactive intermediate: epoxonium ions. Chapter 1 provides a brief review of bicyclic epoxonium ions and methods for their generation, as well as their utility in the synthesis of interesting heterocycles. Furthermore, Chapter 1 illustrates …

Cyclobutanone Inhibitor Of Cobalt-Functionalized Metallo-Γ-Lactonase Aiia With Cyclobutanone Ring Opening In The Active Site, Cory T. Reidl, Romila Mascarenhas, Thahani S. Habeeb Mohammad, Marlon R. Lutz Jr, Pei W. Thomas, Walter Fast, Dali Liu, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

An α-amido cyclobutanone possessing a C10 hydrocarbon tail was designed as a potential transition-state mimetic for the quorum-quenching metallo-γ-lactonase autoinducer inactivator A (AiiA) with the support of in-house modeling techniques and found to be a competitive inhibitor of dicobalt(II) AiiA with an inhibition constant of Ki = 0.007 ± 0.002 mM. The catalytic mechanism of AiiA was further explored using our product-based transition-state modeling (PBTSM) computational approach, providing substrate-intermediate models arising during enzyme turnover and further insight into substrate–enzyme interactions governing native substrate catalysis. These interactions were targeted in the docking of cyclobutanone hydrates into the active site of …

Records Of Enriched Uranium Atmospheric Deposition In Pond Sediments In Piketon, Oh, Brianna Herner, Brian Majestic, Michael Ketterer

DU Undergraduate Research Journal Archive

The enrichment of uranium, often for nuclear weapons programs and commercial nuclear reactors, produces higher concentrations of radioactive uranium 235 (²³⁵U) than what naturally occurs, which can pose a human health hazard. The most abundant naturally occurring uranium isotope is ²³⁸U, which is still radioactive, however a higher concentration of ²³⁵U skews the observed isotopic uranium distribution. The Department of Energy Portsmouth Gaseous Diffusion Plant, located near Piketon, OH, enriched uranium from 1954 to 2001 and ²³⁵U pollution has recently been detected in air and sediment samples in the surrounding community. The extent of the …

Cu-Promoted C-H Bond Hydroxylation Inspired By Cu-Dependent Metalloenzymes, Rachel Trammell

Chemistry Theses and Dissertations

From 2003 to 2015, Schӧnecker and Baran proposed a dinuclear Cu/O₂ species in their mechanistic proposal for the hydroxylation of sp³ C-H bonds within their systems (proposed based on yields). Inspired from the site selectivity of this methodology and poor analysis of the mechanism, the first project was inspired to re-examine the sp³ C-H bond hydroxylation by Schrӧnecker and Baran and perform an intensive investigation into understanding how Cu/O₂ interact which led us to propose a new mechanism based on the evidence collected (i.e., LCu^II-hydroperoxide species that undergoes homolytic O-O bond cleavage). From there …

Metal Salt Hydrolysis For Electrochemically Active Conducting Polymer Nanocomposites, Hongmin Wang

Arts & Sciences Electronic Theses and Dissertations

The diversity of nanostructures obtained from organic polymerization is limited when compared to the vast amount of inorganic nanostructures. This dissertation will focus on a synergistic mechanism between organic polymerization and in situ inorganic salt hydrolysis for developing electrochemically active organic-inorganic hybrid nanostructures. The degree of polymerization, crystallinity and doping level of the conjugated polymer backbone is controlled using oxidative radical vapor-phase polymerization resulting in organic semiconductors featuring high crystallinity and superior electrical conductivity. An aqueous metal salt solution of iron (III) chloride serves as an oxidant for initiating the polymerization and interestingly, this inorganic salt hydrolyzes in situ producing …

Integrated Mass Spectrometry-Based Method In Protein Chemistry: Metal-Binding Protein And Integral Membrane Protein, Chunyang Guo

Arts & Sciences Electronic Theses and Dissertations

Most biological processes are associated with protein catalysis. Characterizing protein structure, therefore, is crucial for understanding biological function. Mass spectrometry (MS)-based methods have emerged as a pivotal biophysical tool to interrogate protein structures; they can characterize protein-ligand/protein complexes that are refractory to conventional high-resolution means such as X-ray crystallography, Cryo-EM, and nuclear magnetic resonance (NMR) spectroscopy, in part owing to high molecular weight and significant flexibility. The integrated MS-based platform will provide topology and structural information of proteins from sketch to detail; native MS identifies protein complexes’ composition and stoichiometry; hydrogen-deuterium exchange MS (HDX-MS) detects the protein complexes’ dynamic change …

Modeling Small Molecule Metabolism In Human Liver Microsome To Better Predict Toxicity Risk, Na Le Dang

Arts & Sciences Electronic Theses and Dissertations

Adverse drug reactions (ADRs) are a serious problem with increasing morbidity, mortality, and health care costs worldwide. In the U.S., ADRs are responsible for more than 50% of acute liver failure cases and are the fourth most common cause of death, costing 100,000 lives annually.Idiosyncratic adverse drug reactions (IADRs) are immune-mediated hypersensitivity ADRs that are difficult to foresee during drug development. IADRs are often caused by reactive metabolites produced during drug metabolism. These reactive metabolites covalently attach to cellular components, and the resulting conjugates may provoke toxic immune response. Because reactive metabolites are short-lived, they can be difficult to detect. …

Synthesis And Characterization Of Putative Triplet Sensitizers In The Dark Pathway To Cyclobutane Pyrimidine Dimers Of Dna, Yanjing Wang

Arts & Sciences Electronic Theses and Dissertations

The cyclobutane pyrimidine dimer (CPD) is the major photoproduct resulting from direct absorption of UVB radiation in sunlight by DNA that results in C to T mutations found in human skin leading to skin cancer. CPDs can also be produced through the action of photosensitizers that can absorb longer wavelength UVA that is not absorbed efficiently by DNA and transfer triplet energy to the DNA. Most recently, CPDs was discovered to be formed in the dark following UV irradiation of melanocytes. This dark pathway was proposed to result from an indirect pathway to CPDs that involves triplet energy transfer from …

In-Situ Imaging Of Surface Heterogeneity In Semiconductor Photocatalysts Using Singlemolecule Fluorescence Microscopy, Meikun Shen

Arts & Sciences Electronic Theses and Dissertations

Metal oxide semiconductors have been used as promising photocatalysts to convert solar energy into useful fuels, such as water splitting, carbon dioxide reduction, and nitrogen fixation reactions. However, the typical metal oxide photocatalysts' efficiency often suffers from their weak visible light absorption and low charge carrier mobilities. One common strategy to mitigate these limitations is to introduce oxygen vacancies into the lattice of the semiconductor photocatalysts. This strategy has been applied to many metal oxide photocatalysts, such as titanium oxide, tungsten oxide, and zinc oxide, and oxygen vacancies indeed enhance their catalytic activities. Various roles of oxygen vacancies have all …