Chemistry Commons^™

Recycling And Reuse Of Radioactive Materials, Thomas Joseph O'Dou

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Radiochemistry Program at the University of Nevada, Las Vegas (UNLV) has a Radiation Protection Program that was designed to provide students with the ability to safely work with radioactive materials in quantities that are not available in other academic environments. Requirements for continuous training and supervision make this unique program capable of turning out graduates that have an understanding of contamination and dose control techniques that complement their knowledge of the elements that they work with. The Program has also adopted a radionuclide recovery and reuse program that has provided materials from other universities, government agencies, and private companies …

Sample Preparation Techniques For The Improvement Of Analytical Measurements: Capillary-Channeled Polymer Fibers Employed In Protein Solid Phase Extraction Applications And Characterization Of Active Components In Botanical Dietary Supplements, Carolyn Burdette

All Dissertations

The task of sample preparation encompasses many challenges and demands for analytical techniques. Appropriate preparative steps can be the determining factor between successful measurements and failures. Too little preparation can lead to the inability to detect analytes due to low concentrations, insufficient extraction of analytes, and/or strong matrix effects; exhaustive preparation steps increases analysis times, the potential for analyte losses, and the difficulty to obtain consistent reproducible results. Discussed here are several examples of analytical techniques where sample preparation is critical and can be used to improve existing techniques. Capillary-channeled polymer (C-CP) fibers used for solid phase extraction (SPE) protein …

New Applications Of Mass Spectrometry For Drug And Lipid Analysis, Elizabeth Lauren Emerson

Graduate Theses and Dissertations

Mass spectrometry is an important tool used in many different disciplines and settings that include forensics, drug discovery, environmental analysis, and proteomics. Gas chromatography - mass spectrometry (GC-MS) and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI - TOF MS) are two of the most important instruments used for analysis of compounds. Chapters 1 and 2 of this discussion use GC-MS for the investigation of synthetic cannabinoids in `K2' incense products and the detection of metabolites in urine samples from individuals suspected of consuming these mixtures. Analytical standards were synthesized and used for identification and confirmation of structures. Detection of …

Refractive Index Chemical Sensing With Noble Metal Nanoparticles, Phillip Blake

Graduate Theses and Dissertations

Chemical sensing is a key component in modern society, especially in engineering applications. Because of their widespread impact, improvements to chemical sensors are a significant area of research. One class of sensors, plasmonic sensors, is being heavily researched because of their ability to detect low levels of analyte in near real time without destroying the analyte. This work studies a new class of plasmonic sensor that utilizes diffractive coupling to improve sensor performance. Specifically, this work outlines the first study of diffractive coupling sensors with typical nanoparticle shapes. Sensitivity of this new class of sensor is directly compared to typical …

Solvation Energy Of Biomolecular Structures: A Study Of The Effect Of Salt On Biomolecules Through Implicit As Well As Explicit Solvation Methods, Mihir Date

All Dissertations

In the current dissertation, studies related to solvation energy of protein structures using implicit as well explicit solvation methods have been discussed. Special focus is given to explore effect of salt on the fold stability of proteins and enzymes. Salt plays a crucial role in the functioning of all proteins, enzymes and nucleic acids. Change in salt concentration of the medium has large impact on stability and activity of these biological macromolecules. Therefore exploring mechanism of salt effect on them and development of an efficient model to calculate the salt effect has fundamental as well as practical importance in the …

Synthesis And Biological Activity Of Aminoglycosides And 1,4-Naphthoquinone Derivatives, Marina Fosso Yatchang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research described in this dissertation is at the interface of organic chemistry and biology, and it aimed at designing and synthesizing biologically active molecules for the possible development of therapeutic agents.

Spinal muscular atrophy is an incurable disease that affects 1 in every 6000 babies, making it the leading genetic cause of infant mortality. While no treatment is available, efforts are being taken to solve this issue. Part of the work outlined in this dissertation was carried out in collaboration with researchers from the University of Missouri to investigate a potential therapeutic for this disease.

In addition, the continuous …

In Situ Measurements Of Electron-Beam-Induced Surface Voltage Of Highly Resistive Materials, Joshua Hodges

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Surface charging and subsequent electrostatic discharge due to interactions with the space environment is one of the primary concerns of spacecraft charging studies. Laboratory measurements of the evolution of surface voltages and dissipation currents under simulated space conditions are the primary method used to determine the response of key spacecraft materials to diverse incident fluxes. Increasing the database of information for the electronic properties of insulating materials can assist spacecraft designers in mitigating the harsh effects of the space environment.

The Utah State Materials Physics Group, with the funding of the NASA James Webb Space Telescope project and personnel support …

The Use Of Rhenium(Vii) Oxide As A Catalyst For The Substitution Of Hemiacetals, Michael W. Richardson

Department of Chemistry: Dissertations, Theses, and Student Research

Rhenium (VII) oxides have proven to be mild and versatile catalysts in organic chemistry. They have previously been utilized to catalyze the transposition of allylic aclohols, Prins reaction, and reductive amination to name a few examples. This thesis reports the application of Re(VII) oxide in the substitution of hemi-acetals with a wide array of nucleophiles including oxo-, thio-, and peroxy-nucleophiles. These reactions proceed efficiently with rapid reaction times and high yields.

Adviser: Patrick H. Dussault

Lack Of P53 Affects The Expression Of Several Brain Mitochondrial Proteins: Insights From Proteomics Into Important Pathways Regulated By P53, Ada Fiorini, Rukhsana Sultana, Eugenio Barone, Giovanna Cenini, Marzia Perluigi, Cesare Mancuso, Jian Cai, Jon B. Klein, Daret K. St. Clair, D. Allan Butterfield

Chemistry Faculty Publications

The tumor suppressor protein p53 has been described "as the guardian of the genome" for its crucial role in regulating the transcription of numerous genes responsible for cells cycle arrest, senescence, or apoptosis in response to various stress signals. Although p53 promotes longevity by decreasing the risk of cancer through activation of apoptosis or cellular senescence, several findings suggest that an increase of its activity may have deleterious effects leading to selected aspects of the aging phenotype and neurodegenerative diseases. There is the link between p53 and oxidative stress, the latter a crucial factor that contributes to neurodegenerative processes like …

Hygroscopic Growth And Ccn Activity Of Hulis From Different Environments, Thomas B. Kristensen, Heike Wex, Bettina Nekat, Jacob K. Nøjgaard, Dominik Van Pinxteren, Douglas H. Lowenthal, Lynn Mazzoleni, Katrin Dieckmann, Christian Bender Koch, Thomas F. Mentel, Hartmut Herrmann, A. Gannet Hallar

Department of Chemistry Publications

[1] Humic-like substances (HULIS) constitute a significant fraction of aerosol particles in different environments. Studies of the role of HULIS in hygroscopic growth and cloud condensation nuclei (CCN) activity of aerosol particles are scarce, and results differ significantly. In this work the hygroscopic growth and CCN activity of water extracts (WE) and HULIS extracted from particulate matter (PM) collected at a polluted urban site (Copenhagen, Denmark), a rural site (Melpitz, Germany) and the remote site Storm Peak Laboratory (Colorado, USA) were investigated. Measurements of inorganic ions, elemental carbon, organic carbon and water soluble organic carbon (WSOC) within the PM confirmed …

Preparation Of Nitrogen-Containing Heterocycles Via Cyclization Of Pyridine-Tethered Organolithiums, Elizabeth Archer

Master's Theses

No abstract provided.

Microfabrication, Characterization, And Application Of Carbon Nanotube Templated Thin Layer Chromatography Plates, And Functionalization Of Porous Graphitic Carbon, David S. Jensen

Theses and Dissertations

This dissertation contains the following sections. Chapter 1 contains a detailed description of the theory of thin layer chromatography (TLC). Chapter 2 describes the benefits and practical considerations of elevated temperatures in liquid chromatography (LC). The porous graphitic carbon (PGC) I modified as part of my work is often used in elevated temperature LC. Chapter 3 shows a thermodynamic analysis of chromatographic retention at elevated temperature, and Chapter 4 contains a closer look at the van 't Hoff equation in LC and how it can be used in retention modeling. In Chapter 5, I describe a new procedure for microfabricating …

Deposition And Characterization Of Hydrophobic Coatings, Vipul Gupta

Theses and Dissertations

Hydrophobic coatings find application in various sectors of the economy including to electronics, textiles, optical devices, and in scientific and commercial equipment. These different applications demand that different hydrophobic coatings posses a range of properties that may include smoothness or roughness, thicknesses on the order of a monolayer or a micron, robustness or the ability to dissolve quickly, transparency or opacity, water resistance or water permeability, electrical conductivity, oleophobicity, etc. However, whatever the final/desired properties, deposition via dry-deposition processes offers significant advantages, including greater reproducibility, increased environmental friendliness, and cost effectiveness on an industrial scale. Herein I explore the chemical …

A Cucurbit[8]Uril Sponge, Vijayakumar Ramalingam, Sharon K. Kwee, Lisa M. Ryno, Adam R. Urbach

Chemistry Faculty Research

This paper describes a convenient approach to quantitative removal of the synthetic host cucurbit[8]uril (Q8) from aqueous mixtures using a sepharose resin coated in memantine groups to selectively sequester Q8 in the presence of competing hosts and guests. The “Q8 sponge” can separate Q8 from Q6 and reverse the Q8-mediated dimerization of peptides.

Titration Calorimetric Study Of The Interaction Among Calcium, Bile Salts, And The Tetracyclines, Karla Arias

College of Science and Health Theses and Dissertations

Tetracyclines are a group of antibiotics that are known to bind physiologically relevant metal ions, such as Ca2+, for antibacterial activity. The formation of the[ antibiotic-Ca2+l complex can interact with components in the gastrointestinal tract, including the bile salts, and reduce their absorption into the blood plasma after oral administration. Metal ion interactions between Ca2+ and tetracycline have been the focus of numerous studies while interactions with minocyclinc and tigccyclinc have been scarcely explored. Isothermal titration calorimetry (ITC) was employed to study the interaction of three members of the tetracycline family, tetracycline (TtC), minocyclinc (MC), and tigecycline (TgC), with …

Investigations Into Background Correction And Retention Time Alignment To Enhance Quantitative Chemometric Analysis Of Comprehensive Two-Dimensional Liquid Chromatography-Diode Array Detection Data, Robert Allen

Theses and Dissertations

The focus of the projects presented here was to develop possible solutions to three issues commonly encountered during chemometric analysis of comprehensive two-dimensional liquid chromatography diode array detector (LCxLC-DAD) data. The focus of the first project was to determine a means of performing background correction that removed two background ridges. The methods of simply subtracting out a mean blank sample, singular value decomposition based background correction (SVD-BC) and asymmetrically weighted least squares (AWLS) were compared. AWLS was found to be the only background correction technique to fully remove the ridges. However, AWLS was also found to attenuate the peak intensity …

Proposed Coherent Trapping Of A Population Of Electrons In A C60 Molecule Induced By Laser Excitation, Thomas George, G.P. Zhang

Chemistry & Biochemistry Faculty Works

This Letter demonstrates the possibility of generating coherent population trapping in C60. Similar to a three-level Λ system, C60 has a forbidden transition between the highest occupied molecular orbital (HOMO) (|a⟩) and the lowest unoccupied molecular orbital (LUMO) (|c⟩), but a dipole-allowed transition between HOMO and LUMO+1 (|b⟩) and between |b⟩ and |c⟩. We employ two cw laser fields, one coupling and one probe. The strong coupling field is switched on first to resonantly excite the transition between |b⟩ and |c⟩. After a delay, the probe is switched on; the coherent interaction between the coupling and probe fields traps the …

Recent Results In Protein Kinase Inhibition For Tropical Diseases, David Rotella

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Protein kinases are becoming widely investigated targets for treatment of protozoal parasitic tropical diseases such as malaria and leishmaniasis. The search for potent, selective inhibitors of these parasitic enzymes has been aided by the extensive variety of structures prepared for human diseases. Genomic approaches to target identification and validation have aided the search. Substantial progress has been made and research is continuing to expand in an effort to find safe, effective drug candidates for these difficult to treat and widespread diseases.

Design And Synthesis Of Fluorescence Turn-On Probes For Iron, Randy K. Jackson

Master's Theses

No abstract provided.

Effects Of Heterogeneity In Small Π-Type Dimers: Homogeneous And Mixed Dimers Of Diacetylene And Cyanogen, Kari L. Copeland, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

The homo- and heterogeneous dimers of diacetylene (H-C≡C-C≡C-H) and cyanogen (N≡C-C≡N) were studied using ab initio electronic structure computations to probe the effects of heterogeneity on noncovalent interactions between systems with delocalized π electron networks. Full geometry optimizations and harmonic vibrational frequencies were performed using the robust coupled-cluster with single and double and perturbative triple excitations (CCSD(T)) method with the triple-ζ plus 2 sets of polarization functions TZ2P(f,d)++ basis set. Seven basic configurations were examined for each dimer (cross, stacked, parallel-slipped, parallel-tipped, linear, T-shaped and Y-shaped), but only four stationary points were identified on the potential energy surfaces (PESs) of …

Flexural Rigidity Measurements Of Biopolymers Using Gliding Assays, Douglas S. Martin, Lu Yu, Brian L. Van Hoozen Jr.

Chemistry and Physics Faculty Articles

Microtubules are cytoskeletal polymers which play a role in cell division, cell mechanics, and intracellular transport. Each of these functions requires microtubules that are stiff and straight enough to span a significant fraction of the cell diameter. As a result, the microtubule persistence length, a measure of stiffness, has been actively studied for the past two decades. Nonetheless, open questions remain: short microtubules are 10-50 times less stiff than long microtubules, and even long microtubules have measured persistence lengths which vary by an order of magnitude.

Here, we present a method to measure microtubule persistence length. The method is based …

Nanoporous Gold As A Solid Support For Protein Immobilization For The Development Of Immunoassays, And For Biomolecular Interaction Studies, Binod Prasad Pandey

Dissertations

Nanoporous gold (NPG) is a versatile material of high surface area to volume ratio that can be readily modified with self-assembled monolayers of alkanethiols to which biomolecules can be linked. NPG presents new opportunities for the development of immunoassays, and for the development of carbohydrate based assays. This thesis explores the use of NPG as a support for self-assembled monolayers, their linkage to antibody-enzyme conjugates for immunoassay development, and for the study and application of carbohydrate-protein interactions. Direct kinetic electrochemical immunoassays were developed on NPG for prostate specific antigen (PSA) and carcinoembryonic antigen (CEA). The decrease in enzymatic conversion of …

Capturing Fleeting Intermediates In A Catalytic C-H Amination Reaction Cycle, Richard H. Perry, Thomas J. Cahill Iii, Jennifer L. Roizen, Justin Du Bois, Richard N. Zare

Chemistry and Physics Faculty Articles

We have applied an ambient ionization technique, desorption electrospray ionization MS, to identify transient reactive species of an archetypal C–H amination reaction catalyzed by a dirhodium tetracarboxylate complex. Using this analytical method, we have detected previously proposed short-lived reaction intermediates, including two nitrenoid complexes that differ in oxidation state. Our findings suggest that an Rh-nitrene oxidant can react with hydrocarbon substrates through a hydrogen atom abstraction pathway and raise the intriguing possibility that two catalytic C–H amination pathways may be operative in a typical bulk solution reaction. As highlighted by these results, desorption electrospray ionization MS should have broad applicability …

Mechanism Of Action Studies On A New Class Of Anticancer Nucleosides, Megan E. Browning

Theses and Dissertations

We have completed mechanism of action studies on a new class of anticancer nucleosides typified by a novel nucleoside discovered in our lab, MAP-870. In order to study the mechanism of MAP-870, several experiments were completed on a colorectal adenocarcinoma cell line, HT-29, including trypan blue cell count, sulforhodamine B assays, flow cytometry of cell cycle, propidium iodide incorporation, and phosphatidylserine externalization, Caspase-Glo3/7 assays, DNA fragmentation gel, cyclophilin A release gel, PAMPA, and confocal imaging. Sulforhodamine B assays show that MAP-870 does indeed cause growth inhibition and cell death in the model tested. PAMPA assays show that MAP-870 does not …

Conformations Of Islet Amyloid Polypeptide Monomers In A Membrane Environment: Implications For Fibril Formation, Mojie Duan, Jue Fan, Shuanghong Huo

Chemistry

The amyloid fibrils formed by islet amyloid polypeptide (IAPP) are associated with type II diabetes. One of the proposed mechanisms of the toxicity of IAPP is that it causes membrane damage. The fatal mutation of S20G human IAPP was reported to lead to early onset of type II diabetes and high tendency of amyloid formation in vitro. Characterizing the structural features of the S20G mutant in its monomeric state is experimentally difficult because of its unusually fast aggregation rate. Computational work complements experimental studies. We performed a series of molecular dynamics simulations of the monomeric state of human variants in …

Spectral Data For "Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations: Synthetic Studies Directed Toward The Frondosins", Do W. Lee, Rajesh K. Pandey, Sergey V. Lindeman, William A. Donaldson

Natural Products Synthesis via Organoiron Methodology

Spectral data created in the course of the research project. Supports specific findings in "Reactivity of acyclic (pentadienyl)iron(1+) cations: Synthetic studies directed toward the frondosins".

A short, 4-step route to the scaffold of frondosin A and B is reported. The [1-methoxycarbonyl-5-(2′,5′-dimethoxyphenyl)pentadienyl]Fe(CO)₃⁺ cation was prepared in two steps from (methyl 6-oxo-2,4-hexadienoate)Fe(CO)₃. Reaction of this cation with isopropenyl Grignard or cyclohexenyllithium reagents affords (2-alkenyl-5-aryl-1-methoxycarbonyl-3-pentene-1,5-diyl)Fe(CO)₃ along with other addition products. Oxidative decomplexation of these (pentenediyl)iron complexes, utilizing CuCl₂, affords 6-aryl-3-methoxycarbonyl-1,4-cycloheptadienes via the presumed intermediacy of a cis-divinylcyclopropane.

Dynamic Electron Correlation Effects On The Ground State Potential Energy Surface Of A Retinal Chromophore Model, Samer Gozem, Mark Huntress, Igor Schapiro, Roland Lindh, Alexander A. Granovsky, Celestino Angeli, Massimo Olivucci

Chemistry Faculty Publications

The ground state potential energy surface of the retinal chromophore of visual pigments (e.g., bovine rhodopsin) features a low-lying conical intersection surrounded by regions with variable charge transfer and diradical electronic structures. This implies that dynamic electron correlation may have a large effect on the shape of the force fields driving its reactivity. To investigate this effect, we focus on mapping the potential energy for three paths located along the ground state CASSCF potential energy surface of the penta-2,4-dieniminium cation taken as a minimal model of the retinal chromophore. The first path spans the bond length alternation coordinate and intercepts …

New Multidetector Solution Could Lead To Safer Alternatives To Faulty Silicone Breast Implants, Judit D. Puskas, Geof Wyatt

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

The article discusses the effort of the University of Akron's Department of Chemical and Biomolecular Engineering to pursue research which aims to reduce or eliminate capsular contracture associated with breast implants. It notes that the new multidetector nanotechnology developed by researchers can be better alternative to silicone gel-filled breast implants. It mentions that the new technology can also help in early diagnosis and imaging of breast cancer.

Unlocking The Knowledge: The Key To Delivering The Compliance And Business Benefits Outlined In Ich Q10 For Medicinal Product Manufacture, Nuala Calnan (Editor)

Conference Papers

This paper presents the challenges of delivering a holistic approach to the Pharmaceutical Quality System (Q10) expectations for medicinal product manufacture. It reviews the key findings from the recent ‘Operational Excellence in the Pharmaceutical Industry’ St. Gallen Uni. benchmarking report and explores the theme of 'Knowledge as the Key'. It explores how can we utilise familiar OPEX, Lean/ Six Sigma tools to capture this knowledge and deliver the expectations and opportunities for ICH Q10 and discusses this researchers study in the area of knowledge management and operational excellence.
It also includes a review of both the Regulatory Drivers and recent …

Differential Effects Of The Hydrophobic Surfactant Proteins On The Formation Of Inverse Bicontinuous Cubic Phases, Mariya Chavarha, Ryan W. Loney, Kamlesh Kumar, Shankar B. Rananavare, Stephen B. Hall

Chemistry Faculty Publications and Presentations

Prior studies have shown that the biological mixture of the two hydrophobic surfactant proteins, SP-B and SP-C, produces faster adsorption of the surfactant lipids to an air/water interface, and that they induce 1-palmitoyl-2-oleoyl phosphatidylethanolamine (POPE) to form inverse bicontinuous cubic phases. SP-B has a much greater effect than SP-C on adsorption. If the two proteins induce formation of the bicontinuous structures and faster adsorption by similar mechanisms, then they should also have differential ability to form the cubic phases. To test this hypothesis, we measured small angle X-ray scattering on the individual proteins combined with POPE. SP-B replicated the doserelated …