Chemistry Commons^™

Preparation And Characterization Of Extraction Chromatography Resins Using N-Donor Extractants For Trivalent Actinide And Lanthanide Separations, Christopher L. Klug

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actinide and lanthanide elements exist in the geosphere and biosphere due to both natural abundances and anthropogenic activities. The investigation of the presence and transport of actinides through the environment is of great scientific interest. In order to prepare environmental samples for precise measurements, the individual actinides must be separated from the chemically similar lanthanides, and from neighboring actinides. Existing extraction chromatography resins are either poorly suited for this separation, have bleeding problems, are not reusable, or fail the CHON principle. In an effort to resolve these issues, malonamides and N-donor extractants from the BTP and BTBP classes of solvent …

Antimicrobial Activity Of D-Lenolate®, Andy Phui

UNLV Theses, Dissertations, Professional Papers, and Capstones

Olive trees are one of the most important fruit trees in the Mediterranean. Although not validated by research, olive leaves are traditionally believed to fight off fever and infections. It has been shown that olive leaf extracts possess antimicrobial activity. Olive leaf extracts contain polyphenols. One of the major phenolic compounds is oleuropein. Oleuropein and other polyphenols have been shown to exhibit antimicrobial activity. East Park Research (EPR) developed an extraction process that they claim does not alter the chemical composition of the olive leaves. The extract is known by the commercial name d-lenolate®. Studies have provided evidence that d-lenolate®, …

Bacillus Cereus And Bacillus Anthracis Germination Kinetics: A Michaelis-Menten Approach, Helen Luu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bacillus species are rod-shaped, gram-positive bacteria that are capable of producing endospores. In this dormant stage, the endospores can persist in hostile physical and chemical environments. Once conditions become favorable, the spores germinate into actively dividing cells, vegetative cells. Germination is a crucial step for the pathogenicity of the Bacilli in affecting a host organism.

Our study applies mathematical approaches to spore germination to determine whether the binding of one germinant will affect the binding of another germinant. We pursued this approach with two different species, B. cereus and B. anthracis, both pathogenic organisms. B. cereus is a widely known …

The In-Situ Removal Of Menthofuran From Peppermint Oil And Subsequent Reactions Of The Solid-Supported Adduct, Robert Joseph Justice Ii

Dissertations

Menthofuran is an aromatic heterocyclic compound found naturally in the essential oil of Mentha piperita L. or peppermint. Natural peppermint oil may contain between approximately 2 to 8% menthofuran.

Peppermint oil is a complex mixture of over 350 identified chemical compounds; market demands dictate the extent of processing the oil undergoes prior to being introduced into consumer goods. Menthofuran has long been known to readily autoxidize, either alone or within the peppermint oil matrix, leading to a discolored oil with negative organoleptic consequences that adversely affects its commercial viability. Therefore, a facile method for selective removal of menthofuran was developed …

Comparison Of Rna Quality From Stressed And Unstressed Recombinant Escherichia Coli, Mary Alice Salazar

All Theses

High quality, intact RNA is required for DNA microarray studies, cloning, and reverse transcriptase polymerase chain reaction (rt-PCR) analysis. There are several analytical methods used to assess the RNA quality. The RNA Integrity Number (RIN) from the Agilent Bioanalyzer is one quality control assay used to evaluate RNA. For recombinant Escherichia coli cultured under stressful conditions the RNA profiles obtained using the Agilent Bioanalyzer indicate RNA degradation; however, RNA obtained and purified in parallel from unstressed recombinant cultures indicate acceptable RNA values without significant degradation. We proposed that for stressed E. coli the RIN value is not necessarily indicative of …

Characterization Of The N-Terminal Domains And Disease-Causing Mutations Of The Human Wilson Protein, Joshua Mutambuki Muia

Dissertations

The Wilson protein (ATP7B) is a copper transporting ATPase that is involved in copper trafficking and homeostasis. Unlike the other known P-type ATPases, it possesses six homologous metal binding domains at the N-terminal end. Several mutations in the gene coding for this protein lead to Wilson disease, a hepatic disorder characterized by impaired excretion of copper in the bile, and accumulation of copper in body organs such as the liver, brain, kidney, and eye cornea. Characterization of various regions of expressed and purified ATP7B has been hampered by its low stability, aggregation and degradation.

In this research, novel methods were …

Self-Assembly Of Architecturally Complex Block Copolymers, Juan Hinestrosa

All Dissertations

The term self-assembly denotes the formation of complex structures from simpler building blocks, resembling the manner in which Nature generates functional systems. In this pursuit, block copolymers present a great opportunity to study the interactions, dynamics and self-assembly of soft matter. Block copolymers have the ability to self-assemble into thermodynamically stable microphase segregated domains of precise shape and size, which are controlled by the chemistry of the constituent blocks, their size and connectivity, temperature and solvent conditions. Specifically, in this body of work two different types of branched copolymers with polystyrene (PS) and polyisoprene (PI) constituents are studied. The complex …

Synthesis Of Meta-Terphenyl Scaffolded Molecules For Catalysis And Sensor Applications, Brad Morgan

All Dissertations

The utility of the m-terphenyl has been observed in a wide variety of applications since its first discovery. The tunable conformational flexibility contributes to the unique properties and resulting applications thereof. Chapter 1 goes into detail about the concepts used throughout and defines the tools needed to understand the chemistry in the
resulting chapters.
The primary use of the m-terphenyl herein is as a canopy that shields a pocket created underneath the central ring. Functionalization within this pocket allows metal binding in defined coordination environments. with the use of donor ligands attached to the flanking rings. The applications of these …

Diffusion Monte Carlo Studies Of Quantum Solvation: Finding Nodal Functions Of Wavefunctions Using A Genetic Algorithm, Christina Hansen Howell

Undergraduate Honors Capstone Projects

Solvation is important in many chemical reactions since most reactions occur in solution. Recently, progress has been made using helium-4 nanodroplets as the solvent at temperatures close to absolute zero. Because helium-4 is a superfluid it solvates dissolved molecules much differently that does a conventional solvent. This opens up the possibility of performing new types of chemistry in the superfluid environment. However, the nature of the interaction of the dissolved species with the solvent remains poorly understood. The basic question to be answered in this project is: how does the quantum solvent perturb the rotational dynamics of the solute particles? …

An Exploratory Study Of Methicillin-Resistant Staphylococcus Aureus And Sccmec Elements Obtained From A Community Setting Along The Texas Border With Mexico, David R. Ammons, Raghuveer Puttagunta, Jose C. Granados, Georgina De La Garza, George Eyambe, Joanne Rampersad-Ammons

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

An exploratory study of methicillin-resistant Staphylococcus aureus (MRSA) and SCCmec elements in bacteria along the Mexican border of south Texas was performed. Between September and December of 2008, 375 swabs of anterior nares were self-collected by students attending the University of Texas-Pan American (UTPA) and cultured for MRSA. Fifty seven bacterial isolates were kept for further analysis that included suspected MRSA and other SCCmec-containing bacteria. Isolates were examined for the presence of nuc, mecA, lukS-PV, and spa genes using PCR. SCCmec and spa typing were also performed. Seven S. aureus isolates were found …

Characterization Of Plutonium Particles Originating From The Bomarc Accident -1960, Richard Charles Gostic

UNLV Theses, Dissertations, Professional Papers, and Capstones

Within the U.S. arsenal, 32 accidents with nuclear weapons were reported between 1950 and 1980. One of these accidents occurred at McGuire AFB in 1960. A BOMARC missile armed with a nuclear warhead caught on fire and as a result the warhead was destroyed. Sub-millimeter particles consisting of weapons grade plutonium (WGPu) produced by this accident were distributed around the site and remained in the environment for 47 years. Soil cores known to contain WGPu particles produced by this accident were obtained. The particles were localized and removed from the soil with the aid of high resolution computed tomography. The …

Field And Smog Chamber Studies Of Agricultural Emissions And Reaction Products, Derek J. Price

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agricultural emissions are an important contributor to atmospheric aerosol. These emissions include nitrogen containing organic compounds, primarily as amines, which have not been well investigated to date. Although there have been several studies that have looked at the emission of gas phase amines, there are only a few studies that have focused on ambient amine-based aerosol. There have also only been a handful of smog chamber studies that have investigated amine aerosol chemistry. Kinetic studies have looked at the reactions of amines with OH and ozone. However, amine reactions with nitrate radical (NO₃) are not well understood. Several …

A Synthetic Biological Engineering Approach To Secretion- Based Recovery Of Polyhydroxyalkanoates And Other Cellular Products, Elisabeth Linton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The costs associated with cellular product recovery commonly account for as much as 80% of the total production expense. As a specific example, significant recovery costs limit commercial use of polyhydroxyalkanoates (PHA), which comprise a class of microbially-accumulated polyesters. PHAs are biodegradable compounds that are of interest as a sustainable alternative to petrochemically-derived plastics. Secretion-based recovery of PHAs was studied to decrease PHA production costs. Type I and II secretory pathways are commonly used for the translocation of recombinant proteins out of the cytoplasm of E. coli. Proteins were targeted for translocation using four signal peptides (HlyA, TorA, GeneIII, …

Pulsed-Laser Excited Photothermal Study Of Glasses And Nanoliter Cylindrical Sample Cell Based On Thermal Lens Spectroscopy, Prakash Raj Joshi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research in this dissertation presents Pulsed-Laser Excited photothermal studies of optical glasses and cylindrical sample cell.

First, a study of a photothermal lens experiment and the finite element analysis modeling for commercial colored glass filters is done. The ideal situation of a semiinfinite cylinder approximate model used to describe the photothermal lens experiment requires the boundary condition that there is no transfer of heat from the glass to surrounding when the glass is excited with a laser. The finite element analysis modeling for photothermal signal with coupling heat with surrounding shows the thermal heat transfer between the glass surface …

Library Synthesis Of Anticancer And Antibacterial Agents Via Azide Chemistry, Jianjun Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Various anticancer and antibacterial agents have been synthesized via azide chemistry by taking advantage of carbohydrate. Starting from the synthesis of 14 glycosyl azides, a library of carbohydrate-oxazolidinone conjugates and a library of carbohydrate-cyclopamine conjugates with biological interests were synthesized based on a highly efficient "click reaction" assisted by sonication. Some of the conjugates have improved solubility and enhanced anticancer activity.

A library of neomycin B derivatives with various modifications at the 5" position has been synthesized. Two leads exhibit prominent activity against both methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Antibacterial activities were measured when combined with other …

Dynamics Of Van Der Waals Clusters: Theoretical And Computational Studies, Jordan Aleksander Ramilowski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The marriage of two very powerful techniques – cryogenic matrix isolation spectroscopy and seeded supersonic molecular beams – has led to the development of a novel type of cryogenic matrix isolation spectroscopy in ultracold, near 0 K, He droplets. The technique known as helium nanodroplet isolation (HENDI) has seen tremendeous experimental interest over the past 20 years; this in turn has resulted in the availability of spectroscopic data for many molecules and clusters embedded in He clusters. The experimental findings have motivated a large number of theoretical calculations. This dissertation focuses on theoretical and computational studies of the rotational dynamics …

Classification, Synthesis And Characterization Of Pyridyl Porphyrin Frameworks, Lucas D. Devries

Department of Chemistry: Dissertations, Theses, and Student Research

Structural analysis of a solid-state material is vital because the structure often determines the physical (or chemical) properties of the material. An understanding of the relationship between structural components and bulk properties can be used to design materials with specific properties. To achieve such understanding, two things are required: a rigorous structural analysis method and a study of the properties of materials with noteworthy structural features. In this thesis, the author reviews 44 pyridyl porphyrin frameworks in an effort to determine how these framework structures are formed, and if any overreaching trends can be observed. The observed trends are used …

Determination Of Polymer Molecular Weight Distributions: Dosy, Maldi, Gpc, Nathan A. Meredith

Honors Capstone Projects and Theses

No abstract provided.

Green Chemistry Using Bismuth(Iii) Salts: Synthesis Of Cyclic Acetals And Allylation Of Tetrahydropyranyl Ethers And Aldehydes, Scott W. Krabbe

Honors Projects

Research in our group focuses on environmentally friendly organic synthesis using bismuth compounds. With increasing environmental concerns, the need for environmentally friendly organic synthesis following Green Chemistry principles has assumed increased importance. The Pollution Prevention Act, passed in 1990, was especially important in increasing an interest in Green Chemistry, which is the design and redesign of chemical processes with a view of improving safety. Our group focuses on synthetic methodology i.e. the transformation of one functional group to another. Such transformations are of special relevance in the pharmaceutical industry for manufacture of life saving drugs. Many of the current organic …

Nanostructured Poly(3,4-Ethylenedioxythiophene)–Metalloporphyrin Films: Improved Catalytic Detection Of Peroxynitrite, Serban Peteu, Pubudu Peiris, Ermias Gebermichael, Mekki Bayachou

Chemistry Faculty Publications

We investigated in this paper the sensing performance of inherently conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), functionalized with hemin (iron protoporphyrin) as an electrocatalytic reporter. The sensing platform is prepared by electrodeposition of a composite film of hemin–PEDOT on a 30-μm diameter carbon fiber electrode (CFE). The polymerized films were characterized by field emission scanning electron microscopy (FESEM), which pointed to nanostructured films with tortuous pores. The electrocatalytic oxidation of peroxynitrite was characterized by cyclic voltammetry as well as other electrochemical methods. The catalytic current is proportional to the analyte's concentration. Optimized hemin–PEDOT modified CFEs were utilized for the first time to …

Mixed-Metal Cluster Synthesis: [Re(Co)3(Μ-S2Nc7H4)]2 As A Precursor For Tri- And Tetranuclear 2-Mercaptobenzothiolato Capped Clusters, Shishir Ghosh, Kamrun N. Khanam, Md. Kamal Hossain, G. M. Golzar Hossain, Daniel T. Haworth, Sergey V. Lindeman, Graeme Hogarth, Shariff E. Kabir

Chemistry Faculty Research and Publications

The readily prepared [Re₂(CO)₆(μ-S₂NC₇H₄)₂] (1) reacts with Group 8 trimetallic carbonyl clusters to yield new mixed-metal tri- and tetranuclear clusters. With [Os₃(CO)₁₀(NCMe)₂] at 80 °C the tetranuclear mixed-metal cluster [Os₃Re(CO)₁₃(μ₃-C₇H₄NS₂)] (2) is the only isolated product. With Ru₃(CO)₁₂ products are dependent upon the reaction temperature. At 80 °C, a mixture of tetranuclear mixed-metal [Ru₃Re(CO)₁₃(μ₃-C₇H₄NS₂)] (5) …

Ribosomal Rna Mutations That Inhibit The Activity Of Transfer-Messenger Rna Of Stalled Ribosomes, Jacob N. Crandall

Theses and Dissertations

In eubacteria, stalled ribosomes are rescued by a conserved quality-control mechanism involving transfer-messenger RNA (tmRNA) and its protein partner SmpB. Mimicking a tRNA, tmRNA enters stalled ribosomes, adds Ala to the nascent polypeptide, and serves as a template to encode a short peptide that tags the nascent protein for destruction. To further characterize the tagging process, we developed two genetic selections that link tmRNA activity to cell death. These negative selections can be used to identify inhibitors of tagging or to identify mutations in key residues essential for ribosome rescue. Little is known about which ribosomal elements are specifically required …

New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam Rath, Eike Bauer

Chemistry & Biochemistry Faculty Works

New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR’2 (R = binaphthyl, R’ = CH3, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the …

New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer

Educator Preparation & Leadership Faculty Works

New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR’2 (R = binaphthyl, R’ = CH3, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the …

Synthesis Of Polyazamacrocycle Molecular Tweezers As A Host For Polyoxoanions, Marie Sutor, Ronald Grider, Rebecca Roesner, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

Macrocyclic Pendant Arm Extension: An Application Of The Husigen 1,3-Dipolar Cycloaddition Reaction, Cory Kline, Rebecca Roesner, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

The Happy Marriage Between Laser And Supersonic Expansion, Timothy Zwier, M. G. Mellon Distinguished Professor Of Chemistry

John Wesley Powell Student Research Conference

No abstract provided.

Cadmium, Copper, Iron, And Zinc Concentrations In The Kidneys Of Grey Wolves (Canis Lupus) From Alaska, Idaho, Montana, And The Northwest Territories, Susan Blunck, Emily Jones, Kelly Petersen, Given Harper, Facutly Advisor, Jeffrey Frick, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

Imaging The Topography And Monitoring The Electrochemical Activity Of Biological Samples, Erica Woodall, Emma Dewalt, Faculty Advisor, Melinda Baur, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

Development Of A Discovery Laboratory To Observe And Quantify Protein Denaturation And Coagulation In Egg White Albumin, Elizabeth Ave Maria, Melinda Baur, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.