Digital Commons Network^™

Global Estimates Of Mineral Dust Aerosol Iron And Aluminum Solubility That Account For Particle Size Using Diffusion-Controlled And Surface-Area-Controlled Approximations, Qin Han, Charles S. Zender, J. Keith Moore, Clifton S. Buck, Ying Chen, Anne Johansen, Christopher I. Measures

All Faculty Scholarship for the College of the Sciences

Mineral aerosol deposition is recognized as the dominant source of iron to the open ocean and the solubility of iron in the dust aerosol is highly variable, with measurements ranging from 0.01–80%. Global models have difficulty capturing the observed variations in solubility, and have ignored the solubility dependence on aerosol size. We introduce two idealized physical models to estimate the size dependence of mineral aerosol solubility: a diffusion‐controlled model and a surface‐area‐controlled model. These models produce differing time‐ and space‐varying solubility maps for aerosol Fe and Al given the dust age at deposition, size‐resolved dust entrainment fields, and the aerosol …

Hierarchy Of Supramolecular Synthons In The Of Design Multi-Component Crystals, Padmini Kavuru

USF Tampa Graduate Theses and Dissertations

Most of the biological systems in nature are sustained by molecular self-assemblies which are the finest examples of supramolecular architectures. Non-covalent interactions are key concepts which govern these molecular assemblies. Inspired by these examples crystal engineering emerged as an important tool in supramolecular chemistry which aids in the invention of new molecular structures with desired properties. Understanding of how the molecules interact at the molecular levels enables one to rationally design novel solid forms with modulated physicochemical properties. This feature of crystal engineering has heightened its position in materials chemistry and is currently one of the most well studied fields …

Silica Supported Silver Nanoparticles Catalyst Systems For Oxidation Of Dbt In Crude Oil., Ashlie Santaliz, Brenda Torres, Maryam Zarei, Manuel Ramos, Russel R. Chianelli

COURI Symposium Abstracts, Summer 2012

Metal nanoparticles (NP’s) have become a subject of intense interest in various fields of chemistry and physics primarily because of its catalytic activity at their specific surfaces. Their catalytic activity depending solely of their factes, it is recomendable to achieve six-fold symmetry along with edge sites, ideal places for the attachment of molecules. The aim of this project is to achieve the synthesis of NP-Ag and their functionalizatiin using supported on silica to later perform an oxidation model reaction of diobenzothiophene (DBT) to diobenzenethiophene-sulfone. The DBT oxidation reaction was performed in a reflux system using DBT and silica solved in …

The Importance Of The Rotor In Hydrazone-Based Molecular Switches, Xin Su, Timo Lessing, Ivan Aprahamian

Dartmouth Scholarship

The pH-activated E/Z isomerization of a series of hydrazone-based systems having different functional groups as part of the rotor (R = COMe, CN, Me, H), was studied. The switching efficiency of these systems was compared to that of a hydrazone-based molecular switch (R = COOEt) whose E/Z isomerization is fully reversible. It was found that the nature of the R group is critical for efficient switching to occur; the R group should be a moderate H-bond acceptor in order to (i) provide enough driving force for the rotor to move upon protonation, and (ii) stabilize the obtained Z configuration, to …

New Primers Reveal The Presence Of A Duplicate Histone H3 In The Marine Turtle Leech Ozobranchus Branchiatus, Triet Minh Truong, Audrey E. Mcgowin Ph.D., Philip Lavretsky, Jeffrey L. Peters Ph.D.

Chemistry Student Publications

Marine leeches, specific to sea turtles, have been implicated as potential vector organisms in the spread of fibropapillomatosis (FP), a pandemic neoplastic disease with green turtles (Chelonia mydas) having the highest affliction rate. Polymerase chain reaction identified two independent, seemingly functional histone H3 loci for marine turtle leeches Ozobranchus branchiatus collected from C. mydas in Florida and Hawaii. Primers were developed to amplify each product separately. These novel markers will be useful in identifying ectoparasites in FP research, evaluating other histone variants, and chromatin dynamics regulation studies.

This poster was created and presented by Triet M. Truong at the Wright …

Design And Synthesis Of Novel Fluorescent Nucleoside Analogues, Nada Abdulnasir Elsharif

Electronic Theses and Dissertations

This project aimed to obtain a set of fluorescent nucleoside analogues that closely resemble cytosine with extending the aromatic surface (extended conjugation) for enhance the photophysical properties. In addition to synthesize new fluorescent nucleoside analogues and evaluate their photophysical properties, this project aimed to understand the effects of donor substituent on the tC photophysical properties.

The main goal of these studies is to develop highly fluorescent nucleotide analogues. We first were looking to synthesize tC^C fluorescent nucleotide with the pyrimido[4,5-b]quinolone. In this part, 2-chloro-3- formylquinoline was easily prepared, yet the cyclization of 2-chloro-3- formylquinoline with urea or guanidine HCl …

Evidence That Aberrant Protein Metabolism Contributes To Chemoresistance In Multiple Myeloma Cells, Richard K. Sipes, Xue Xia, Brian S. Lewis, Nicholas E. Burgis

Chemistry and Biochemistry Faculty Publications

Multiple myeloma (MM) is an incurable B lymphocyte cancer. To date, a comparative analysis of global protein metabolism for the MM cell line CCL-155 (RPMI-8226) and the non-cancerous B lymphocyte cell line CCL-156 (RPMI-1788) has not been published. Here, we report that both global protein synthesis and degradation occur at a higher rate in MM cells and demonstrate that alkylating agents can reduce global protein degradation in both cell lines, but the effect is greater in CCL-156 cells. Treatment with melphalan plus the proteasome inhibitor MG132 reduced global protein degradation for MM cells to roughly 60% of that seen without …

Specific Soluble Oligomers Of Amyloid-Β Peptide Undergo Replication And Form Non-Fibrillar Aggregates In Interfacial Environments, Amit Kumar, Lea C. Paslay, Daniel Lyons, Sarah E. Morgan, John J. Correia, Vijayaraghavan Rangachari

Faculty Publications

Aggregates of amyloid-β (Aβ) peptides have been implicated in the etiology of Alzheimer disease. Among the different forms of Aβ aggregates, low molecular weight species ranging between ∼2- and 50-mers, also called “soluble oligomers,” have emerged as the species responsible for early synaptic dysfunction and neuronal loss. Emerging evidence suggests that the neurotoxic oligomers need not be formed along the obligatory nucleation-dependant fibril formation pathway. In our earlier work, we reported the isolation of one such “off-pathway” 12–18-mer species of Aβ42 generated from fatty acids called large fatty acid-derived oligomers (LFAOs) (Kumar, A., Bullard, R. L., Patel, P., Paslay, L. …

Structural Characterization Of Zn(Ii)-, Co(Ii)-, And Mn(Ii)-Loaded Forms Of The Arge-Encoded N-Acetyl-L-Ornithine Deacetylase From Escherichia Coli, Ye Tao, Jacob E. Shokes, Wade C. Mcgregor, Robert A. Scott, Richard C. Holz

Chemistry Faculty Research and Publications

The Zn, Co, and Mn K-edge extended X-ray absorption fine structure (EXAFS) spectra of the N-acetyl-l-ornithine deacetylase (ArgE) from Escherichia coli, loaded with one or two equivalents of divalent metal ions (i.e., [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)], [Co(II)Co(II)(ArgE)], [Mn(II)_(ArgE)], and [Mn(II)Mn(II)(ArgE)]), were recorded. The Fourier transformed data (FT) for [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)] and [Co(II)Co(II)(ArgE)] are dominated by a peak at 2.05 Å, that can be fit assuming five or six light atom (N,O) scatterers. Inclusion of multiple-scattering contributions from the outer-shell atoms of a histidine-imidazole ring resulted in reasonable Debye–Waller factors for these contributions and a slight reduction …

Identifying Risk Factors For Disparities In Breast Cancer Mortality Among African-American And Hispanic Women, Nancy Tian, Pierre Goovaerts, T. Benjamin Zhan, T. Edwin Chow, J. Gaines Wilson

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

Background: This study evaluated the risk factors associated with racial disparities in female breast cancer mortality for African-American and Hispanic women at the census tract level in Texas from 1995 to 2005.

Methods: Data on female breast cancer cases were obtained from the Texas Cancer Registry. Socioeconomic and demographic data were collected from Census 2000. Network distance and driving times to mammography facilities were estimated using Geographic Information System techniques. Demographic, poverty and spatial accessibility factors were constructed using principal component analysis. Logistic regression models were developed to predict the census tracts with significant racial disparities in breast cancer mortality …

Nanoenergetic Composite Based On I2o5/Al For Biological Agent Defeat, Mkhitar Hobosyan, Alexander V. Kazanksy, Karen S. Martirosyan

Physics & Astronomy Faculty Publications

The risk of bioterrorism events involving the intentional airborne release of contagious agents has led to development of new approaches for bio agent defeat technologies both indoors and outdoors. This report describes nanoenergetic gas generators (NGG) system that exhibit long term stability and superior release of biocidal substances for destruction of pathogenic bacteria. The effect of iodine vaporization on destroying of Escherichia coli (E-coli, HB101 K-12 strain) by using expressing Green Fluorescent Protein (GFP) was investigated. HB101 K-12 has been genetically modified to prevent its growth unless grown on an enriched medium. To obtain quantitative data we used pGLO transformation …

Design And Synthesis Studies Of New S-Adenosyl-L-Methionine Analogues, Shanshan Wu

Theses

S-Adenosyl-L-Methionine (SAM), which is involved in methyl group transfers, is the second most abundant coenzyme in the human body. It is made from adenosinetriphosphate (ATP) and methionine catalyzed by adenosyltransferase. Methyltransferases (MTs) transfer the activated methyl group from the sulfur center to a specific position in a variety of substrates, e.g., DNA, RNA, proteins, and secondary metabolites. Methyltransferases have been linked to various diseases, including cancer.

In recent years, more and more SAM analogues have been reported. These analogues show activities in biological target labeling. The purpose of this thesis is to design and synthesize new SAM analogues to inhibit …

Size Dependent Antimicrobial Properties Of Sugar Encapsulated Gold Nanoparticles, Lakshmisri Manisha Vangala

Masters Theses & Specialist Projects

The antimicrobial properties of dextrose encapsulated gold nanoparticles (dGNPs) with average diameters of 25 nm, 60 nm, and 120 nm (± 5 nm) synthesized by green chemistry principles were investigated against both Gram-negative and Gram-positive bacteria. Studies were performed involving the effect of the dGNPs on the growth, morphology and the ultrastructural properties of bacteria. dGNPs were found to have significant dose dependent antibacterial activity which was directly proportional to their size and also their concentration. The microbial assays revealed the dGNPs to be bacteriostatic as well as bactericidal. The dGNPs exhibited their bactericidal action through the disruption of the …

Monitoring Photocatalytic Degradation Of X-Ray Contrast Media With Raman Spectroscopy, Sabina Salkic

Masters Theses & Specialist Projects

X-ray contrast media such as diatrizoate and iohexol have been found in wastewater and drinking water and are difficult to remove because they are resistant to water treatment processes. A removal process can be started with ultraviolet photocatalytic degradation of X-ray contrast media in the presence of titanium dioxide or other catalysts. Raman spectra of diatrizoate and iohexol were taken in an aqueous solution in the presence and absence of titanium dioxide during exposure to ultraviolet radiation. Raman intensity is directly proportional to concentration; therefore, we can measure the rate of the reaction based on changes in the Raman spectrum. …

Lipid Peroxides And Glutathione Status In Human Progenitor Mononuclear (U937) Cells Following Exposure To Low Doses Of Nickel And Copper, William Y. Boadi, Shalandus Harris, Justin B. Anderson, Samuel E. Adunyah

Chemistry Faculty Research

Effects of Cu2+, Ni2+ or Cu2+ + Ni2+ on lipid peroxide and glutathione (GSH) levels in U937 cells were investigated. Cells were treated with 0, 5, 10, and 20 µM of Cu2+ and/or Ni2+ and H2O2 (0.01 mM) and incubated for 24 hours at 37°C. Lipid peroxides were measured by the thiobarbituric acid assay (TBA). GSH intracellular levels were assayed by the GSH assay kit from EMD/Calbiochem (San Diego, California, USA). Cu2+ or Ni2+ significantly (P < 0.01) increased lipid peroxides in a dose-dependent manner, compared to controls. The effect was more pronounced for Cu2+, compared to the Ni2+-treated samples. Cu2+ + Ni2+ increased lipid peroxides in a significant (P < 0.001), dose-dependent manner, compared to Cu2+ or Ni2+ alone (i.e., ratio of 2.5:1-fold for combined versus single treatments, respectively). Cu2+ or Ni2+ significantly decreased GSH levels in U937 cells, with the effect being pronounced for Cu2+. Cu2+ + Ni2+ metal ions significantly (P < 0.001) depleted cells of GSH in a dose-dependent manner. Ethylene diamine tetraacetic acid (EDTA) at 50 or 100 µM moderately reduced the Cu2+- or Ni2+-induced effects on GSH levels. Interestingly, GSH levels generally decreased to half (except for the combined metal dose of 20 µM at 100 µM EDTA) of its level at the highest metal concentration tested for both the single or combined treatments. In conclusion, multiple exposures of cells to metal ions may be lethal to cells, compared to their single treatments.

High Resolution Spectroscopy: The Study Of Isobutylene, Tabetha Lynn Osborn

Student Theses and Dissertations

The explosive bouquet theory suggests that canines trigger on volatile organic species within an explosive and not the pure explosive. Modeling an explosive detection scheme after this theory, an experimental design using mid infrared sources was established at the ArCLAS facility. A calibration program, documented within this thesis, was created in a Visual Basic platform as an Excel Add-In. The calibration program converts time based spectra collected with a germanium etalon into frequency spaced scans and then to known frequencies to allow spectral assignments to rovibrational transitions of molecules of interest. Additionally, the analysis of isobutylene, a volatile organic bouquet …

Patent: Methods Of Treating Fgf21-Associated Disorders, Brian R. Boettcher, Shari L. Caplan, Douglas S. Daniels, Bernhard Hubert Geierstanger, Norio Hamamatsu, Stuart Licht, Andreas Loew, Stephen Craig Weldon

Chemistry Faculty Publications

The invention relates to the identification of new polypeptide and protein variants of fibroblast growth factor 21 (FGF21) that have improved pharmaceutical properties. Also disclosed are methods for treating FGF21-associated disorders, includ ing metabolic conditions.

Magnetic Ordering And Structural Phase Transition In Strained Ultrathin Srruo3/Srtio3 Superlattice, Mingquiang Gu, Xiaoshan Wu, Guoping Zhang

Symposium 2012

No abstract provided.

Cloning And Characterization Of Sas0754, A Hypothetical Protein From Community Associated Staphylococcus Aureus, Unknown Unknown

Symposium 2012

Community associated Staphylococcus aureus (strain MSSA476) is a gram positive cocci capable of infecting many different parts of the body and known to cause serious infections that can be fatal, such as bacterial arthritis and acute endocarditis. To find effective ways of fighting against CA-MRSA strains we must learn more about their ability to infect. The focus of this study was cloning and characterization of a protein referred to as SAS0754. The size of SAS0754 is 340 amino acids and the gene sequence is 1023 nucleotides. The hypothetical function of this protein is that it is an extracellular matrix binding …

A Convenient Synthesis Of 2,6-Dichlorohomonicotinic Acid, Chase Buchanan, Richard W. Fitch

Symposium 2012

In our synthetic efforts toward the alkaloid phantasmidine, we required a convenient source of the title compound. Herein, we describe a short synthesis of 2,6-dichlorohomonicotinic acid by direct allylation of 2,6-dichloropyridine with LDA/allyl chloride, followed by permanganate oxidation of the side chain [figure1]. Yields for the allylation are high, while permanganate oxidation required more adjustment. Successful conditions require the modest acidification of the mixture with acetic acid and cleanup by acid base workup. No chromatography is needed.

Convenient Parallel Synthesis Of Alkyl- And Aryl-S-Tert-Butyl Thiothers, Rebecca Norcross, Jessica Stanfield, Richard W. Fitch

Symposium 2012

While preparing novel cysteine derivatives as oxidation catalysts, we needed S-tert-butylcysteine. We also examined acid-promoted tert-butylation of thiols using tert-butanol as reagent and solvent. While cysteine and aminoethanethiol work well using tBuOH in 4M HCl, other thiols fail in the aqueous environment and aerobic conditions. We examined a variety of aliphatic and aromatic thiols in tBuOH with H2SO4 catalysis and found that argon sparging and the use of 1 eq of acid led to good yields in a parallel format.

Synthesis Of S-Ribosyl-L-Homocysteine And Analogs Modified At The Homocysteine-C3 Position, Ruoyi Liu

Master's Theses

Quorum sensing (QS) is a process of bacterial cell-to-cell communication that conveys population density information in order to coordinate gene expression to produce synchronized behaviors. QS regulates the expression of virulence genes in many species of bacteria; hence, the manipulation of QS pathways may lead to treatment options against many bacterial diseases. The LuxS enzyme converts S-ribosyl-L-homocysteine (SRH) into homocysteine (HCys) and 4(S),5-dihydroxypentane-2,3-dione (DPD), which is the precursor of autoinducer-2 (AI-2). Thus, inhibitors of LuxS could prevent QS by halting the conversion of SRH to AI-2 rendering the cell “uncommunicative”. This work shows the successful chemical synthesis …

Controlled Attachment Of Nanoparticles To Layered Oxides, Yuan Yao

LSU New Orleans Theses and Dissertations

A series of oxide materials were modified with different nanoparticles (NPs). Novel cobalt@H₄Nb₆O₁₇ nanopeapod structures were fabricated and magnetic NPs modified oxide nanosheets and nanoscrolls were prepared. Both aqueous method and two-phase method were applied to prepare gold NPs onto oxide nanosheets, nanoscrolls and other nanocrystals.

The combination of H₄Nb₆O₁₇ nanoscrolls and cobalt NPs generate a novel method to fabricate nanopeapod structures. Cobalt NPs were synthesized in the presence of exfoliated H₄Nb₆O₁₇ nanosheets and the resulting magnetic chain structures, formed due to the dipole-dipole interaction, …

Synthesis And Development Of Potential Cb1 Receptor Neutral Antagonists, Kimari Slaughter

LSU New Orleans Theses and Dissertations

Cannabis and its derivatives have been used for both medicinal and recreational purposes. The study of this plant led to the discovery of over 60 cannabinoids, found exclusively in cannabis, that contribute to the behavioral effects of cannabis use, the most common is delta-9-tetrahydrocannabinol. Cannabinoid receptors function to increase activity in the mesolimbic dopamine reward system. Dopamine is a neurotransmitter that plays a major role in addition and its regulation plays a crucial role in mental and physical well-being. There is evidence that CB₁ receptors are important to the reinforcing effects and the development of physical dependence on opiate …

Synthesis And Biological Evaluation Of Rigid Analogues Of Methamphetamines, Andrea N. Forsyth

LSU New Orleans Theses and Dissertations

A series of rigid azetidenyl-based methamphetamine analogs were synthesized from commercially available N-Boc-azetidinone. The benzylideneazetidine analogs were prepared via a Wittig olefination via the ylides generated from the corresponding triphenylphosphonium benzylhalide salts. The substituted benzylazetidine analogs were synthesized from the corresponding benzylideneazetidienes via hydrogention over palladium and platinum catalysts. The benzylideneazetidine and benzyliazetidine analogs were evaluated at monoamine transporters as a part of preliminary structure-activity study for the development of novel monoamine transporter ligands. The binding affinities of the azetidine analogs were determined at dopamine (DAT) and serotonin (SERT) transporters in rat brain tissue preparations. The preliminary in vitro …

Synthesis And Characterization Of Sugar Based Low Molecular Weight Gelators, Hao Yang

LSU New Orleans Theses and Dissertations

Low molecular weight gelators (LMWGs) have gained great attention over the past two decades. These compounds form self-assembled fibrous networks like micelles, cylindrical, sheets, fibers, layers and so on. The fibrous network entraps the solvent and form gel. LMWGs are interesting compounds with many potential applications in material and biomedical sciences.

Many different structures have been found to be good LMWGs. Our interests focus on the carbohydrate based LMWGs. Previously, we have found that several ester derivatives of methyl 4, 6-O-benzylidene-α-D-glucopyranoside are good gelators for organic solvents and aqueous solutions. In this study, in order to understand the …

Active Response Of Polymer Materials From External Stimuli – Solvents And Light; Grafting Reactions On Perovskite Layers, Jianxia Zhang

LSU New Orleans Theses and Dissertations

The active response of a series of polymeric materials was investigated. Both solvent activated and light activated thin films and wire systems show dynamic behaviors when exposed to different stimuli.

Solvent mediated fluxional behavior of polymer thin films involved extensive, rapid curling both on infusion and evaporation of good solvents. These films can be either lab-fabricated ones or commercial ones, and the curling behavior can be as fast as seconds. Conditions including polymer materials, chosen solvents, and film geometry can affect the behavior.

Methods that allowed for the creation and retention of distorted wire structures were also developed; the asymmetric …

Synthesis Of Fluorogenic Substrates For The Enzymatic Characterization Of Rv0045c From M. Tuberculosis, Kelly Jo Mckenna

Undergraduate Honors Thesis Collection

Mycobacterium tuberculosis is the pathogenic bacterial agent commonly responsible for tuberculosis, or TB. Although treatment exists for the active form of tuberculosis, no method has been developed for eliminating M tuberculosis in its dormant state. One hypothesized method for the elimination of dormant TB is to develop an inhibitor specific for M tuberculosis esterases and lipases, as these esterases and lipases are essential to the survival of dormant TB infection. In this research, the substrate specificity of the Rv0045c esterase from M tuberculosis was studied due to the essential role of Rv0045c in TB metabolism and its dissimilarity to other …

Chiral Recognition In Amino Acid And Peptide Based Chiral Ionic Liquids, Daniel Mccray Kroupa

Undergraduate Honors Thesis Collection

In this study, amino acid and peptide based chiral ionic liquids (ILs) were prepared and their chiral recognition ability probed using circularly polarized luminescence (CPL) spectroscopy. Potential applications of amino acid and peptide based chiral ILs include asymmetric synthesis and chiral resolution. The amino acid based chiral ILs under study were prepared from amino acid methyl ester cations and bis(trifluoromethane)sulfonamide ([TF2ND anions, specifically L-alanine methyl ester, D-alanine methyl ester, L-Ieucine methyl ester, and L-proline methyl ester. Cationic peptide ILs were prepared from L-alanyl glycine methyl ester cations and [TF2Nr anions and anionic peptide based ILs were prepared from tetrabutylammonium ([TBAt) …

Refining Vibrationally-Resonant Sum Frequency Generation Spectroscopy For Studies Of Interfacial Interactions, Alexander D. Curtis

Theses and Dissertations

Many phenomena of interest to science and engineering occur at interfaces; however, access to, or discrimination of, interfacial interactions has been challenging, especially at buried interfaces. Vibrationally resonant sum-frequency generation (VR-SFG) spectroscopy is a powerful tool for investigating the molecular structure of free or buried interfaces, but spectral analysis has relied on many assumptions. To claim accurate new insights, practitioners must be able to make unique determinations from the data without experimental artifacts affecting the final results. For example, two independent and overlapping studies for the polystyrene/air interface were carried out, but reported different surface structures. Initially, this difference was …