Chemistry Commons^™

Graphite Aerogels And The Formation Mechanism Of Unusual Micron-Sized Rod And Helical Structures, Clarissa Ann Wisner

Doctoral Dissertations

"Pyrolysis at 800 ºC under argon has shown that polyimide (PI), polyacrylonitrile (PAN), polydicyclopentadiene (DCPD) and polybenzoxazine (PBO) aerogels are all viable alternatives to traditional resorcinol-formaldehyde (RF) aerogels as precursors to amorphous carbon aerogels. Subsequent high temperature pyrolysis at 2300 ºC of such carbon aerogels under helium has shown that amorphous carbon from PI and PBO yields the highest degree of graphitization, whereas from RF aerogels yields the lowest.

Those two types of graphite aerogels include also a high concentration of micron-size columnar and helical (screw-like) structures, whose formation is favored by macroporosity and high nitrogen retention in the 800 …

Ru/C: A Simple Heterogeneous Catalyst For The Amination Of Azoles Under Ligand Free Conditions, K. Harsha Vardhan Reddy, B. S.P. Anil Kumar, V. Prakash Reddy, R. Uday Kumar, Y. V.D. Nageswar

Chemistry Faculty Research & Creative Works

A ligand free Ru/C-catalyzed amination of 2-halo azoles with a broad scope of aminating reagents has been developed. A variety of 2-aminoazole derivatives were synthesized in moderate to good yields by utilizing this protocol. The methodology is operationally simple and not sensitive to air and moisture. It provides potentially useful products by using an inexpensive and recyclable catalytic system under ligand free conditions without significant loss of its catalytic activity up to four cycles. This journal is

Wavefunction Methods For The Accurate Characterization Of Water Clusters, J. Coleman Howard, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

Although the first ab initio Hartree-Fock computations of the water dimer were reported more than four decades ago, the detailed characterization of water clusters with sophisticated electronic structure techniques remains an important and vibrant area of research. The field of computational quantum chemistry has made significant advances since those pioneering studies. Geometry optimizations of the water dimer can now be carried out at the CCSDTQ level, and CCSD(T) energies can be computed with the aug-cc-pVTZ basis for clusters as large as (H₂O)₁₇. Some of these high-level studies are starting to reveal that the electronic structure is …

Specific Intracellular Uptake Of Herceptin-Conjugated Cdse/Zns Quantum Dots Into Breast Cancer Cells, Seung-Jin Han, Pierson Rathinaraj, Soo-Young Park, Young-Kyoo Kim, Joon Hyung Lee, Inn-Kyu Kang, Jong-Sik Moon, Jeffrey G. Winiarz

Chemistry Faculty Research & Creative Works

Herceptin, a typical monoclonal antibody, was immobilized on the surface of CdSe/ZnS core-shell quantum dots (QDs) to enhance their specific interactions with breast cancer cells (SK-BR3). the mean size of the core-shell quantum dots (28 nm), as determined by dynamic light scattering, increased to 86 nm after herceptin immobilization. the in vitro cell culture experiment showed that the keratin forming cancer cells (KB) proliferated well in the presence of herceptin-conjugated QDs (QD-Her, 5 nmol/mL), whereas most of the breast cancer cells (SK-BR3) had died. to clarify the mechanism of cell death, the interaction of SK-BR3 cells with QD-Her was examined …

Antioxidant Potential Of Sutherlandia Frutescens And Its Protective Effects Against Oxidative Stress In Various Cell Cultures, Shakila Tobwala, Weili Fan, Connor J. Hines, William Robert Folk, Nuran Ercal

Chemistry Faculty Research & Creative Works

Sutherlandia frutescens (L.) R.Br. (SF) is a South African plant that is widely used to treat stress, infections, cancer, and chronic diseases, many of which involve oxidative stress. The aim of the study was to quantitatively assess the antioxidant potential of SF extracts in cell-free system as well as in cell lines. Dried SF vegetative parts were extracted using six different solvents, and the extracts were assessed for total phenolic and flavonoid contents, total reducing power, iron chelating capacity, and free radical scavenging power, including, scavenging of hydroxyl radicals, superoxide anions, nitric oxide, and hydrogen peroxide. We further investigated the …

Deuterium Tracer Study Of The Mechanism Of Iron Catalyzed Fischer-Tropsch Synthesis, Yunxin Liao

Online Theses and Dissertations

The Fischer-Tropsch Synthesis (FTS) was invented in 1920s, shortly after its invention, it became an important way to produce synthetic fuels. The FTS is also an important way to understand the origin of life. Even though the FTS has been used to produce liquid fuels commercially for a relatively long time, the mechanism of FTS is still unclear, a mechanism can explain all the experimental observations has not been discovered yet.

By conducting H2/D2 switching experiments we found that there was an inverse isotope effect in the Fe catalyzed FTS. The rate of hydrocarbon production was increased when syngas H2/CO …

Microwave Assisted Chemical Synthesis Using Polydimethylsiloxane, Omniya Alomainy

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Characterizing The Antioxidant Capacity Of Gevalia Traditional Roast Coffee Based On Brew Method, Erica Mendoza

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Critical Phenoneme In A Ternary System Of Water, Isobutyric Acid, And Octanol, Kerry Rice

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Antileishmanial Agents From Sassafras Albidum Bark Extract, Kelly Marie Steinberg

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Identification And Characterization Of Functionally Critical, Conserved Motifs In The Internal Repeats And N-Terminal Domain Of Yeast Translation Initiation Factor 4b (Yeif4b), Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

EIF4B has been implicated in attachment of the 43 S preinitiation complex (PIC) to mRNAs and scanning to the start codon. We recently determined that the internal seven repeats (of ∼26 amino acids each) of Saccharomyces cerevisiae eIF4B (yeIF4B) compose the region most critically required to enhance mRNA recruitment by 43 S PICs in vitro and stimulate general translation initiation in yeast. Moreover, although the N-terminal domain (NTD) of yeIF4B contributes to these activities, the RNA recognition motif is dispensable. We have now determined that only two of the seven internal repeats are sufficient for wildtype (WT) yeIF4B function in …

Structure And Dynamics Of The Hiv-1 Frameshift Element Rna, Kathryn Mouzakis

Chemistry and Biochemistry Faculty Works

The HIV-1 ribosomal frameshift element is highly structured, regulates translation of all virally encoded enzymes, and is a promising therapeutic target. The prior model for this motif contains two helices separated by a three-nucleotide bulge. Modifications to this model were suggested by SHAPE chemical probing of an entire HIV-1 RNA genome. Novel features of the SHAPE-directed model include alternate helical conformations and a larger, more complex structure. These structural elements also support the presence of a secondary frameshift site within the frameshift domain. Here, we use oligonucleotide-directed structure perturbation, probing in the presence of formamide, and in-virion experiments to examine …

Principles And Properties Of Eukaryotic Mrnps, Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

The proper processing, export, localization, translation, and degradation of mRNAs are necessary for regulation of gene expression. These processes are controlled by mRNA-specific regulatory proteins, noncoding RNAs, and core machineries common to most mRNAs. These factors bind the mRNA in large complexes known as messenger ribonucleoprotein particles (mRNPs). Herein, we review the components of mRNPs, how they assemble and rearrange, and how mRNP composition differentially affects mRNA biogenesis, function, and degradation. We also describe how properties of the mRNP "interactome" lead to emergent principles affecting the control of gene expression.

Modified Seed Growth Of Iron Oxide Nanoparticles In Benzyl Alcohol: Magnetic Nanoparticles For Radio Frequency Hyperthermia Treatment Of Cancer, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles have received sustained interest for biomedical applications as synthetic approaches are continually developed for precise control of nanoparticle properties. This thesis presents an investigation of parameters in the benzyl alcohol synthesis of iron oxide nanoparticles. A modified seed growth method was designed for obtaining optimal nanoparticle properties for magnetic fluid hyperthermia. With a one or two addition process, iron oxide nanoparticles were produced with crystallite sizes ranging from 5-20 nm using only benzyl alcohol and iron precursor. The effects of reaction environment, temperature, concentration, and modified seed growth parameters were investigated to obtain precise control over properties …

Structure Assignment And H/D-Exchange Behavior Of Several Glycosylated Polyphenols, Andreas H. Franz, Ilona Serebnitskaya, Gurbir Gudial, Christopher Wallis

College of the Pacific Faculty Articles

The NMR-structures of six polyphenols, resveratrol (1), (-)-epicatechin (2), pelargonidin chloride (3), cyanidin chloride (4), cyanin chloride (5), and keracyanin chloride (6), were fully assigned. For the glycosylated polyphenols 5 and 6, the three-dimensional solution structure and long-range 1 H- 13C-coupling constants across the glycosidic bond were measured. Satisfactory fit to standard Karplus-equations was achieved for glycosides directly attached to the aromatic core in cyanin chloride. Molecular dynamics simulation data in vacuum at the AM1-level of theory were shown to approximate the NMR-solution data reasonably well. Selective HCl-catalyzed H/D-exchange was observed for aromatic protons H6 and H8 in flavonoid structures …

Investigating Dna Barcoding Potentials And Genetic Structure In Ozobranchus Spp. From Atlantic And Pacific Ocean Sea Turtles, Triet Minh Truong

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The Ozobranchidae family is the smallest and least studied hirudinean taxon. Our research includes the largest molecular dataset yet reported for marine ozobranchids (Ozobranchus margoi and Ozobranchus branchiatus) with the most number of documented turtle hosts (57) from the Atlantic and Pacific Oceans to date of any marine turtle epibiont study. Turtle species sampled in this study include loggerheads (Caretta caretta), hawksbill (Eretmochelys imbricata), olive ridley (Lepidochelys olivacea), and green turtles (Chelonia mydas). Phylogenetic analyses of mitochondrial (COI) and nuclear ribosomal (18S and 28S) genes all support the monophyly of marine Ozobranchidae leeches with speciation occurring over an extensive period …

A Chemical Free Approach For Increasing The Biochemical Surface-Enhanced Raman Spectroscopy (Sers)-Based Sensing Capabilities Of Colloidal Silver Nanoparticles, Kevin Michael Dorney

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The unique optoelectronic properties of silver nanoparticles (AgNPs) have led to their explosive use in a multitude of both research and industrial settings in recent years. Localized surface plasmon resonance (LSPR) exhibited by AgNPs has been exploited extensively as a nano-scale probe in a variety of spectroscopic detection modalities, particularly in surface-enhanced Raman spectroscopy (SERS). The SERS effect is highly dependent upon the LSPR interaction with optical laser frequencies, thus optimization of LSPR via specific control of AgNP dimensionality and composition of the surrounding medium is vital for increasing the efficacy of SERS-based nano-sensing. This work aimed to augment LSPR …

The Synthesis Of 1,4-Bis(2-(4-(4-Fluorobenzoyl)Phenoxyethoxy)Benzene And Poly(Aralkyl Ether)S Derived From 1,4-Bis(2-Tosyloxyethoxy)Benzene, Juraj Drzic

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The reaction of 1,4-bis(2-tosyloxyethoxy)benzene or 1,4-bis(bromoethoxy)-benzene with 4-fluoro-4'-hydroxybenzophenone was carried out under a variety of conditions. Changes were made in solvent, reaction time, work-up and base. All attempts to generate a bis(fluorobenzophenone) monomer were unsuccessful. In some cases the presence of the half-product could be determined. In other cases, an elimination product was indicated. The ditosylate, 1,4-bis(2-tosyloxyethoxy)benzene was reacted with bisphenol-A, bisphenol-AF, bis(4-hydroxyphenyl)diphenylmethane and 9,9-bis(4-hydroxyphenyl)fluorene in a dioxane - water solution in the presence of sodium hydroxide to produce four polymers. The polymers were characterized by thermal analysis (TGA) to reveal 5% weight loss temperatures of 338°, 350°, 365° and …

The Synthesis Of Polyimides Containing Oxyalkylene Units, Kristy Wickman

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A series of oxyalkylene containing diamines, 1,4-bis(2-(4-aminophenoxy)-ethoxy)benzene, 2,2-bis[4-(2-(4-nitrophenoxy)ethoxy)phenyl]hexafluoropropane, 9,9-bis(4-(2-(4-nitrophenoxy)ethoxy)phenyl)fluorene, and bis(4-(2-(4-nitrophenoxy)ethoxy)-phenyl)diphenylmethane, has been synthesized from the reduction of 1,4-bis(2-(4-nitrophenoxy)ethoxy)benzene, 2,2-bis[4-(2-(4-nitrophenoxy)ethoxy)phenyl]-hexafluoropropane, 9,9-bis(4-(2-(4-nitrophenoxy)ethoxy)phenyl)fluorene, bis(4-(2-(4-nitrophenoxy)ethoxy)phenyl)diphenylmethane, respectively. The diamine compounds were reacted reacted with 6FDA to obtain the corresponding polyimide. The polymerization was done in a one-pot reaction with m-cresol and isoquinoline. The polyimides displayed glass transition temperatures ranging from 186-231°C and thermal stability <400°C.

Stop Cheating!: An Evaluation Of A Scientific Integrity Writing Strategy In General Chemistry I, Michelle L. Edwards

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Cheating in America has become an epidemic, which has unfortunately spread to academia. Researchers have long been interested in the trends in cheating behavior and the factors that influence these trends among undergraduate college students. Though cheating can take on many forms, in science, there is a deep concern about scientific misconduct related to research. Because training for future scientists begins in undergraduate courses, this study investigated the use of scientific integrity writing strategy in General Chemistry I at Wright State University. The goal of the study was to determine if providing scientific integrity and ethics training, while teaching students …

Routes To N-Heterocycle Functionalized Poly(Arylene Ether Sulfone)S, Jesse L. Picker

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The synthesis of poly(arylene ether sulfone)s, with a pendant aryl iodide, was achieved via nucleophilic aromatic substitution (NAS) polycondensation of 3-iodo-3',5'-difluoro-diphenylsulfone. The polymer series was subjected to amino acid promoted, copper catalyzed coupling reactions with various N-heterocycles. The resulting polymers became crosslinked and insoluble in any organic solvents. The iodo monomer was then subjected to an amino acid promoted, copper catalyzed coupling reaction with carbazole. The successful synthesis of 3'-(9-carbazole) 3,5-difluorodiphenylsulfone is reported. A series of PAES containing a carbazole substituent were synthesized and characterized. The polymers were characterized by a combination of NMR spectroscopy, SEC, TGA, DSC, UV-Vis spectroscopy. …

Reactivity Ratio Controlled Polycondensation As A Route To Synthesize Functional Poly(Arylene Ether)S, Godfred Boakye

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Two monomers, 4',3,5-trifluorodiphenylsulfone, 1, and 4',3,5-trifluorobenzophenone, 2, have been investigated for their potential use as special BB'B''type monomers to synthesize functionalized, linear PAEs via a process called reactivity ratio controlled polycondensation (RRCP). A model study with monomer 1 resulted in a mixture of unreacted starting material, two mono-substitution products (para-and meta-F substitution) and a significant amount of di-substitution products as evidenced by the GC/MS and 13C DEPT-90 NMR spectroscopy. Conversely, subjecting monomer 2 to similar conditions, using 3-aminophenol (3f) as the nucleophile, afforded mono-substitution exclusively. A series of functionalized, linear PAEs polymers were prepared by reaction of compound 2 with …

Advances In Understanding The Molecular Composition Of Dissolved Organic Matter And Its Reactivity In The Environment, Rajaa Mesfioui

Chemistry & Biochemistry Theses & Dissertations

Dissolved organic matter (DOM) is the ultimate product of Earth's systems dynamics. DOM chemical signature is strongly shaped by the interaction among Earth's spheres, such as the atmosphere, the geosphere, the biosphere, and the hydrosphere, but also life and human activity. DOM source, composition, photochemical alteration and availability affect freshwater ecosystems, their carbon and nitrogen fluxes and, thus, the global carbon and nitrogen cycles. The aim of this thesis was to gain an understanding of the molecular composition of DOM and its photochemical and biological reactivity in an environment impacted by anthropogenic disturbance. The York and James River systems within …

Longitudinal Plasmonic Detection Of Glucose Using Gold Nanorods, Ching An Peng, Sushil Pachpinde

Michigan Tech Publications, Part 1

Gold nanorod-based affinity sensors were developed utilizing concanavalin-A/dextran/glucose chemistry to detect glucose. The gold nanorods, synthesized using the seed-mediated method, were first coated with dextran sulfate. The dextran sulfate coating changed the local refractive index, which was observed as a red shift in the longitudinal plasmon band. After the addition of 8 μM concanavalin-A, gold nanorod aggregates were formed as shown by TEM analysis. The corresponding UV-Vis spectrum peak wavelength showed a red shift from 701 nm of dextran sulfate coated gold nanorods to 718 nm of concanavalin-A promoted gold nanorod aggregates. The gold nanorod aggregates were dissociated when 12 …

Van Der Waals Trilayers And Superlattices: Modification Of Electronic Structures Of Mos2 By Intercalation, Ning Lu, Hongyan Guo, Lu Wang, Xiaojun Wu, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We perform a comprehensive first-principles study of the electronic properties of van der Waals (vdW) trilayers via intercalating a twodimensional (2D) monolayer (ML = BN, MoSe₂, WS₂, orWSe₂) between a MoS₂ bilayer to form various MoS₂/ML/MoS₂ sandwich trilayers. We find that the BN monolayer is themost effective sheet to decouple the interlayer vdW coupling of the MoS₂ bilayer, and the resulting sandwich trilayer can recover the electronic structures of the MoS₂ monolayer, particularly the direct-gap character. Further study of the MoS₂/BN superlattices confirms the effectiveness of …

Phosphatase-Inert Glucosamine 6‑Phosphate Mimics Serve As Actuators Of The Glms Riboswitch, Xiang Fei, Thomas Holmes, Julianna Diddle, Lauren Hintz, Dan Delaney, Alex Stock, Danielle Renner, Molly Mcdevitt, David B. Berkowitz, Juliane K. Soukup

David Berkowitz Publications

The glmS riboswitch is unique among generegulating riboswitches and catalytic RNAs. This is because its own metabolite, glucosamine-6-phosphate (GlcN6P), binds to the riboswitch and catalytically participates in the RNA selfcleavage reaction, thereby providing a novel negative feedback mechanism. Given that a number of pathogens harbor the glmS riboswitch, artificial actuators of this potential RNA target are of great interest. Structural/kinetic studies point to the 2- amino and 6-phosphate ester functionalities in GlcN6P as being crucial for this actuation. As a first step toward developing artificial actuators, we have synthesized a series of nine GlcN6P analogs bearing phosphatase-inert surrogates in place …

Metallurgical And Corrosion Assessment Of Submerged Tanker S.S. Montebello, Dana Medlin, James D. Carr, Donald L. Johnson, David L. Conlin

Department of Chemistry: Faculty Publications

The Union Oil Tanker S.S. Montebello was torpedoed and sunk six miles (9.7 km) off the coast of Cambria, California by a Japanese submarine on December 23, 1941, two weeks after the attack on Pearl Harbor. With close proximity to the National Monterey Bay Marine Sanctuary, concern about possible crude oil contamination led to the most recent expedition to the site in October 2011. Assessment of the shell plate found that the average corrosion rate was very low and the structure will remain stable for many decades.

Investigation Of Pyrrolizidine Alkaloids In Foods Using Liquid Chromatography Mass Spectrometry, Caroline Griffin

PhDs

Pyrrolizidine Alkaloids (PAs) are known plant toxins which can cause hepatic veno-occlusive disease (HVOD) in both humans and livestock when ingested. Although PAs are primarily known for their hepatotoxicity they also induce genotoxicity, carcinogenicity and pneumotoxicity. PAs are consumed through plants as food, for medicinal purposes, or as contaminants of agricultural crops. Aside from ingesting the plants directly PA exposure may occur through the consumption of honey produced by bees that visit PA-containing plants or by drinking milk produced by animals that have consumed PA-containing plants. Possible PA contamination in our food chain is a potential health risk.

To assess …

Fabrication Of Nanoporous Gold And Biological Applications, Badharinadh Uppalapati

Theses and Dissertations

FABRICATION OF NANOPOROUS GOLD AND BIOLOGICAL APPLICATIONS By Badharinadh Uppalapati A Dissertation submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University. Virginia Commonwealth University, 2014 Major Director: Maryanne M. Collinson, Professor, Department of Chemistry Fabrication of nanoporous gold electrodes by dealloying Au:Ag alloys has attracted much attention in sensing applications. In the first part of this work, the electrochemical response of the redox active molecule, potassium ferricyanide, in a solution of bovine serum albumin in buffer, serum or blood was studied using nanoporous gold and comparisons made to planar gold. Nanoporous …

Vanadium Complexes Are In Vitro Inhibitors Of Leishmania Secreted Acid Phosphatases, Richard Mendez, Benjamin M. Dorsey, Craig C. Mclauchlan, Matt Beio, Timothy L. Turner, Victoria H. Nguyen, Alexander Su, William Beynon, Jon A. Friesen, Marjorie A. Jones

Faculty Publications – Chemistry

Leishmaniasis is a parasitic disease caused by the protozoa Leishmania. These organisms secrete acid phosphatases during their growth cycle as an important part of cell targeting to host macrophage cells thus allowing for a successful infection. Secreted acid phosphatases (SAP) are reported to play a significant role in the survival of Leishmania cells, thus evaluation of these enzymes is of interest. The inhibition of SAP can be the focus of a new drug therapy. We tested for SAP activity from Leishmania tarentolae following the addition of a series of vanadium complexes including decavanadate. Cell cultures at different stages in their …