Chemistry Commons^™

The Development Of A High Resolution Deep-Uv Spatial Heterodyne Raman Spectrometer, Nirmal Lamsal

Theses and Dissertations

Raman spectroscopy is a light scattering technique that has a huge potential for standoff measurements in applications such as planetary exploration because a Raman spectrum provides a unique molecular fingerprint that can be used for unambiguous identification of target molecules. For this reason, NASA has selected a Raman spectrometer as one of the major instruments for its new Mars lander mission, Mars 2020, in the search for biomarkers that would be the indicators of past or present life. Raman scattering is strongest at UV wavelengths because of the inherent increase in the Raman cross section at shorter wavelengths and because …

Ligand-Induced Magnetic Changes In Metal Thin Films, Fiona Senta Oberbeck-Oxsher

Theses and Dissertations

The investigation of magnetic properties of thin films whose surfaces were modified by organic molecules shows that the addition of any functional group to the surface measurably changes the magnetic properties. The effect often scales with ligand strength and is not limited to surfaces with ferromagnetic properties. Improving upon the technique developed by Knaus et al. [1], a stable and sensitive device was developed to measure this magnetic effect using the planar Hall effect (PHE) in order to shed light onto controversial questions of purported paramagnetism of thiolated gold. There is a measureable non-diamagnetic response of thin gold layers when …

Structural And Functional Studies Of Nicotinamide Adenine Dinucleotide And Streptolysin S Biosynthesis Proteins From Streptococcus Pyogenes, William T. Booth

Theses and Dissertations

Invasive infections caused by Streptococcus pyogenes, also known as Group A Strep (GAS), results in approximately 600,000 deaths annually. With evidence of antibiotic-resistant strains of this bacterium on the rise, there is a need for the identification of new drug targets to control these infections. In our approach we target the quinolinate-salvage pathway (QSP) and the streptolysin S (SLS) biosynthesis pathway. The QSP provides a secondary pathway for NAD+ biosynthesis within this organism; the SLS pathway leads to the formation of a quorum sensing molecule (SLS). We hypothesize that inhibition of the pathways will lead to GAS cell death or …

Applications Of Molecular Modelling And Structure Based Drug Design In Drug Discovery, Sreya Mukherjee

USF Tampa Graduate Theses and Dissertations

Calcium ions have important roles in cellular processes including intracellular signaling, protein folding, enzyme activation and initiation of programmed cell death. Cells maintain low levels of calcium in their cytosol in order to regulate these processes. When activation of calcium-dependent processes is needed, cells can release calcium stored in the endoplasmic reticulum (ER) into the cytosol to initiate the processes. This can also initiate formation of plasma membrane channels that allow entry of additional calcium from the extracellular milieu. The change in calcium levels is referred to as calcium flux. A key protein involved in initiation of calcium flux is …

Aggregation-Induced Emission Enhancement In Boron Difluoride Complexes Of 3-Cyanoformazanates, Ryan R. Maar, Joe Gilroy

Chemistry Publications

Boron difluoride (BF₂) complexes of 3-cyanoformazanates exhibit aggregation-induced emission enhancement in THF-water mixtures due to their severely twisted N-aryl substituents which restrict intramolecular motion and π stacking upon aggregation.

Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, Venkatesh Eppili

USF Tampa Graduate Theses and Dissertations

Water is the essential part of every organism and it is also a vital constituent of healthy living and diet. Unfortunately water contamination over the past decade has increased dramatically leading to various diseases. As technology advances, we are detecting many pollutants at smaller levels of concentrations. Arsenic (As) is one of those major pollutants, and Arsenic poisoning is a condition caused due to excess levels of arsenic in the body. The main basis for Arsenic poisoning is from ground water which naturally contains high concentrations of arsenic. A case study from 2007 states that over 137 million people in …

The Progress Of Order-Structured Membrane Electrode Assembly, Shang-Feng Jiang, Bao-Lian Yi

Journal of Electrochemistry

Performances of proton exchange membrane fuel cells (PEMFCs) have been recently improved. However, the cost and Pt loading must be further reduced for the commercialization of PEMFCs. Previous researches have proved that the order-structured electrode is beneficial to the effective utilization of Pt-based catalysts, decreasing the Pt loading and increasing the three-phase boundary for reaction. Especially, the nanostructure thin films (NSTFs) electrode, an ultra-thin catalytic layer developed by 3M Company, demonstrates high performance and durability. Besides, some other researchers have employed the high conductive carbon nanotube arrays or high stable metal oxide arrays as the order-structured catalyst supports for fundamental …

Recent Progress In Solid-State Nmr Study Of Electrode/Electrolyte Materials For Lithium/Sodium Ion Batteries, Gui-Ming Zhong, Zi-Geng Liu, Da-Wei Wang, Qi Li, Ri-Qiang Fu, Yong Yang

Journal of Electrochemistry

Solid state NMR technique is a powerful tool for characterizing the local structure and compositions of solid materials quantitatively. A comprehensive understanding of the structure evolution during the electrochemical reactions of the materials for lithium/sodium ion batteries will be obtained with the combination of solid state NMR, XRD, and XAS methods. Through analyzing solid state NMR spectra, we can obtain the compositions, local structures and ion diffusion dynamics of electrodes, electrolytes and surface layers for lithium/sodium ion batteries, providing an important theoretical support for the design and development of high-performance materials for batteries. In this paper, we review the recent …

Synthesis, Structural Diversity, And Redox Control Of Cyclometalated Monoruthenium Complexes, Zhong-Liang Gong, Jiang-Yang Shao, Yu-Wu Zhong

Journal of Electrochemistry

Cyclometalated ruthenium complexes have received increasing attractions recently due to their excellent redox and photophysical properties. One structural feature of these complexes is that there is a ruthenium-carbon (Ru-C) σ bond presented in the molecule. Three common methods, namely, the “late metalation”, “early metalation”, and “transmetalation” methods, for the synthesis of cyclometalated ruthenium complexes are discussed and summarized. General strategies for the design of cyclometalating ligand and cyclometalated ruthenium complexes are introduced. By using different ancillary ligands, such as pyridine, imidazole, triazole, and pyrimidine, a great number of ruthenium complexes can be prepared. The presence of the Ru-C bond significantly …

Uniform Nanoshells For Functional Materials: Constructions And Applications, Shu-Yi Duan, Wei Zhang, Jun-Yu Piao, An-Min Cao, Li-Jun Wan

Journal of Electrochemistry

As a significant protocol for materials treatment, surface modification has found broad applications in different fields including catalyst, photochemistry, and electrochemistry. Herein, we introduced the representative synthetic methodologies for the constructions of different functional materials with a focus on their core-shell structures. By taking the electrode materials in lithium ion batteries as an example, we demonstrated the importance of surface modification on the electrode materials. Different coating materials ranging from metal oxides, metal phosphates to carbon have been discussed. We also showed that an accurate control on the surface layer can be crucial for optimizing the electrochemical performances of the …

3, 4-Ethylenedioxythiophene Monomer As Safety-Enhancing Additive For Lithium Ion Batteries, Wei-Xiao Ji, Feng Wang, Jiang-Feng Qian, Yu-Liang Cao, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

Safety concern is a major obstacle hindering the wide applications of large-capacity lithium ion batteries (LIBs) in electric vehicles. In this paper, a polymerizable monomer of 3, 4-ethylenedioxythiophene (EDOT) was proposed and tested as an electrolyte additive for enhancing the safety of LIBs. The electro-oxidative polymerization behaviors and influence of PEDOT additive on the thermal behavior of LiCoO₂ cathode, as well as the safety performance and electrochemical properties of LiCoO₂-based LIBs were investigated. The results from cyclic voltammetry (CV) and transmission electron microscope (TEM) characterizations indicated that the monomer additive can be electro-oxidatively polymerized to form a …

Electrochemical And In Situ X-Ray Absorption Fine Structure Study Of Li-Rich Cathode Materials, Meng-Yan Hou, Hong-Liang Bao, Ke Wang, Jian-Qiang Wang, Yong-Yao Xia

Journal of Electrochemistry

A series of the lithium-rich and manganese-based layered structure xLi₂MnO₃•(1-x)LiMn_1/3Ni_1/3Co_1/3O₂ (x = 0.3,0.5,0.7) materials were synthesized by a co-precipitation method, and followed by a solid-state reaction process. By comparing the first cycle efficiency, the reversible discharge capacity, the cycling stability and the voltage decay during the charge/discharge cycling process, the material with the composition of 0.5Li₂MnO₃•0.5LiMn_1/3Ni_1/3Co_1/3O₂was found to show the best electrochemical performance. The lithium storage mechanism and thermal stability of the de-lithiated compound were also investigated …

Electrochemiluminescence Immunosensor Based On Platinum Nanoparticles For The Determination Of Apolipoprotein A1, Ni Liao, Ying Zhuo, Ruo Yuan

Journal of Electrochemistry

In this paper, a novel electrochemiluminescence (ECL) immunosensor for the detection of apolipoprotein A1 was constructed based on flower-like platinum nanoparticles (PtNFs) via a one-pot chemical synthesis method. The PtNFs was used to immobilize the secondary antibody and enzyme (GOD). Then the prepared bioconjugates were introduced onto the electrode via sandwich immunoreactions. Accordingly, the ECL luminophore peroxydisulfate (S₂O₈^2-) was presented in the working buffer solution containing an appropriate amount of glucose. Through the ECL responses of S₂O₈^2- and O₂, a dramatically amplified ECL signal was obtained for the reason …

Communication: Visualization And Spectroscopy Of Defects Induced By Dehydrogenation In Individual Silicon Nanocrystals, Dmitry A. Kislitsyn, Jon M. Mills, Vancho Kocevski, Sheng-Kuei Chiu, William J.I. Debenedetti, Christian F. Gervasi, Benjamen N. Taber, Ariel E. Rosenfield, Olle Eriksson, Ján Rusz, Andrea Mitchell Goforth, George V. Nazin

Chemistry Faculty Publications and Presentations

We present results of a scanning tunneling spectroscopy (STS) study of the impact of dehydrogenation on the electronic structures of hydrogen-passivated silicon nanocrystals (SiNCs) supported on the Au(111)surface. Gradual dehydrogenation is achieved by injecting high-energy electrons into individual SiNCs, which results, initially, in reduction of the electronic bandgap, and eventually produces midgap electronic states. We use theoretical calculations to show that the STS spectra of midgap states are consistent with the presence of silicon dangling bonds, which are found in different charge states. Our calculations also suggest that the observed initial reduction of the electronic bandgap is attributable to the …

Reduced Graphene Oxide (Rgo) Hollow Network Cages For High-Performance Electrochemical Energy Storage, Chi Zhang, Xu-Jun He, Gao-Ren Li

Journal of Electrochemistry

The reduced graphese oxide (RGO) hollow network cages were synthesized via zinc oxide (ZnO) template-assisted electrodeposition. The as-prepared RGO hollow network cages exhibited the multi-level architectures, from nano sheets, porous structures, networks, to 3D microscaled hollow cages, which can simultaneously optimize transport of electroactive species, utilization rate of electrode material, and super capacitive performance. Electrochemical measurements confirmed the superior performance of RGO hollow network cages for supercapacitors (SCs), such as high Csp (393 F⋅g^-1 at 1.0 A⋅g^-1), excellent rate capability (21.2% Csp loss from 1.0 to 20 A⋅g^-1), and superior cycling stability (< 1% Csp loss after 10000 cycles).

The Electrochemical Behavior Of Li+ In Lif-Baf2-Licl Molten Salt System, Shao-Hua Yang, Jun Wang, Xiao-Hui Lai, Hao-Ran Wang

Journal of Electrochemistry

The electrochemical reduction process and rate determining step of Li ion on a tungsten electrode at 1203 K in a LiF-BaF₂-LiCl molten system were studied by cyclic voltammetry, chronoamperometry and chronopotentiometry methods using a three-electrode system and electrochemical workstation AUTOLAB. The results showed that the reduction potential of Li ion was at around -1.0 V on a tungsten electrode as compared with a platinum electrode. The reduction process of Li ion on a tungsten electrode occurred in a single step with the exchange of one electron. Chronoamperograms indicated that the cathode process was controlled by the diffusion step …

Developments Of Photo-Assisted Fuel Cells, Ling-Ling Zhang, Shao-Jun Dong

Journal of Electrochemistry

The exploitation and utilization of fossil fuels have led to serious energy crisis and environmental pollution. In this case, the development of renewable energy is an alternative to traditional energy consumption. Fuel cells (FCs) can convert chemical energy into electricity via the electrochemical reaction, which is green and environment-friendly. Photo-assisted FCs integrate photo-responsive components into FCs, leading to the dual routes of energy conversion including light energy to electricity and chemical energy to electricity, and thus, improving the energy utilization efficiency. The development of photo-assisted FCs is significant for practical application and promising to solve the coming energy crisis. In …

Exploring The Relationship Of Mbd1 Protein Binding Cpg Sites Of Methylated Dna, Shelby L. Scherer

Honors College Theses

Methylated DNA binding (MBD) proteins control transcriptional regulation by binding methylated DNA at CpG islands to modulate transcriptional activation and silencing of specific genes such as tumor suppressors. The goal is to explore the structure/function relationship between MBD proteins and methylated DNA recognition. By synthesizing the methylated DNA binding region of the MBD1 protein, binding studies test the peptide’s affinity and specificity for methylated DNA. Fluorescence, circular dichroism, and thermal denaturation techniques are utilized to determine the binding affinities and structures of peptides. Studies of peptide mutations can monitor the effectiveness of methylated DNA binding compared to the original peptide. …

Spatially Directional Resorcin[4]Arene Cavitand Glycoconjugates For Organic Catalysis In Aqueous Media, Ali Husain Husain

USF Tampa Graduate Theses and Dissertations

Resorcin[4]arenes and their rigid structures “cavitands” offer a unique molecular structure scaffolds suitable for attaching and orienting multi-ligands on their upper rims. Their remarkable structure properties, the relative ease of chemical modification on their either rims or through the multiple phenolic hydroxyl (-OH) groups, manipulating their cavity size and the role of spatial directionality provided by their cores, led synthetic chemist to explore their utilities in the synthesis of valuable resorcin[4]arene/cavitand assemblies with wide range of applications in many research areas such as supramolecular chemistry, host-guest chemistry, glycoconjugates, polymer chemistry, host-guest chemistry, micro-reactors in chemical catalysis and others. In particular, …

Ionic Liquid Extraction Unveils Previously Occluded Humic-Bound Iron In Peat Soil Pore Water, Timothy J. Veverica, Evan S. Kane, Amy Marcarelli, Sarah A. Green

Department of Biological Sciences Publications

Globally, peatland ecosystems store tremendous amounts of C relative to their extent on the landscape, largely owing to saturated soils which limit decomposition. While there is still considerable uncertainty regarding CO₂ production potential below the water table in peatland ecosystems, extracellular Fe reduction has been suggested as a dominant pathway for anaerobic metabolism. However, colorimetric methods commonly used to quantitate Fe and partition between redox species are known to be unreliable in the presence of complex humic substances, which are common in peatland pore water. We evaluated both the standard o-phenanthroline (o-P) Method and an ionic …

Mutation Linked To Autosomal Dominant Nocturnal Frontal Lobe Epilepsy Reduces Low-Sensitivity Α4Β2, And Increases Α5Α4Β2, Nicotinic Receptor Surface Expression, Weston A. Nichols, Brandon J. Henderson, Christopher B. Marotta, Caroline Y. Yu, Chris Richards, Dennis A. Dougherty, Henry A. Lester, Bruce N. Cohen

Chemistry Faculty Publications

A number of mutations in α4β2-containing (α4β2*) nicotinic acetylcholine (ACh) receptors (nAChRs) are linked to autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), including one in the β2 subunit called β2V287L. Two α4β2* subtypes with different subunit stoichiometries and ACh sensitivities co-exist in the brain, a high-sensitivity subtype with (α4)₂(β2)₃ subunit stoichiometry and a low-sensitivity subtype with (α4)₃(β2)₂ stoichiometry. The α5 nicotinic subunit also co-assembles with α4β2 to form a high-sensitivity α5α4β2 nAChR. Previous studies suggest that the β2V287L mutation suppresses low-sensitivity α4β2* nAChR expression in a knock-in mouse model and also that α5 co-expression …

Ua94/4/5 Student / Alumni Personal Papers Southern Normal School, Wku Archives

WKU Archives Collection Inventories

Small collections of personal papers relating to the Southern Normal School.

Synthesis, Properties, And Antibacterial Activity Of Polyphosphonium Semi-Interpenetrating Networks, Tyler John Cuthbert, Tristan Harrison, Paul J. Ragogna, Elizabeth Gillies

Chemistry Publications

The development of new approaches to antibacterial surfaces is of growing interest to combat the spread of harmful bacterial infections. Relative to polyammoniums, polyphosphoniums can exhibit enhanced chemical and thermal stability, but have not yet been widely explored for the preparation of antibacterial surfaces. In this work, polyphosphoniums of varying chain lengths were synthesized by reversible addition-fragmentation chain-transfer polymerization of 4-vinylbenzyl derivatives of triethyl, tributyl, and trioctylphosphonium. These polyphosphoniums were then incorporated into semi-interpenetrating networks (SIPNs) based on tetra(ethylene glycol) diacrylate (TEGDA) via a UV light-initiated curing process. Measurements of cure percentage, gel content, water contact angle, and surface charge …

A Three-Dimensional He–Co Potential Energy Surface With Improved Long-Range Behavior, George C. Mcbane

Peer Reviewed Articles

A weakness of the ‘‘CBS + corr” He–CO potential energy surface (Peterson and McBane, 2005) has been rectified by constraining the potential to adopt accurate long-range behavior for He–CO distances well beyond 15a0. The resulting surface is very similar to the original in the main part of the interaction. Comparison with accurately known bound-state energies indicates that the surface is slightly improved in the region sampled by the highest lying bound states. The positions of shape and Feshbach resonances within a few cm1 of the j 1/4 1 excitation threshold are essentially unchanged. The low-energy scattering lengths changed noticeably. The …

Using Wastewater-Based Epidemiology To Estimate Drug Consumption—Statistical Analyses And Data Presentation, Caleb J. Banta-Green, Alex J. Brewer, Christoph Ort, Dennis R. Helsel, Jason R. Williams, Jennifer A. Field

All Faculty Scholarship for the College of the Sciences

Aim

Analysis of wastewater samples can be used to assess population drug use, but reporting and statistical issues have limited the utility of the approach for epidemiology due to analytical results that are below the limit of quantification or detection. Unobserved or non-quantifiable—censored—data are common and likely to persist as the methodology is applied to more municipalities and a broader array of substances. We demonstrate the use of censored data techniques and account for measurement errors to explore distributions and annual estimates of the daily mean level of drugs excreted per capita.

Measurements

Daily 24-hour composite wastewater samples for 56 …

Synthesis And Biological Activity Of Novel Quorum Sensing Compounds, Joseph Nicholas Capilato

Theses and Dissertations

Bacteria communicate with chemical signals in a process known as quorum sensing. This population density-dependent process involves the bacterial production, release and detection of structurally specific small molecules and enables the bacterial pathogen to regulate its virulence on a population-wide level. Using a variety of chemical and biological techniques, I have studied various quorum sensing systems in several bacteria, including Vibrio cholera and Pseudomonas aeruginosa. A key principle of this research involves the design, synthesis and testing of novel compounds for their biological activity. These molecules are typically based off of an initial lead target, which is often identified …

Crystal Structure Of Di-Aqua-Bis-(7-Di-Ehtyl-Amino-3-Formyl-2-Oxo-2h-Chromen-4-Olato-Κ(2) O (3), O (4))Zinc(Ii) Dimethyl Sulfoxide Disolvate, Aaron B. Davis, Frank R. Fronczek, Karl J. Wallace

Faculty Publications

The structure of the title coordination complex, [Zn(C₁₄H₁₄NO₄)₂(H₂O)₂]·2C₂H₆OS, shows that the Zn^II cation adopts an octa­hedral geometry and lies on an inversion center. Two organic ligands occupy the equatorial positions of the coordination sphere, forming a chelate ring motif via the O atom on the formyl group and another O atom of the carbonyl group (a pseudo--diketone motif). Two water mol­ecules occupy the remaining coordination sites of the Zn^II cation in the axial positions. The water mol­ecules are each hydrogen bonded to …

An Experimental And Theoretical Study Of Ã2A"Π–X~2A' Band System Of The Jet-Cooled Hbbr/Dbbr Free Radical, Mohammed Gharaibeh, Dennis J. Clouthier, Riccardo Tarroni

Chemistry Faculty Publications

The electronic spectra of the HBBr and DBBr free radicals have been studied in depth. These species were prepared in a pulsed electric discharge jet using a precursor mixture of BBr₃ vapor and H₂ or D₂ in high pressure argon. Transitions to the electronic excited state of the jet-cooled radicals were probed with laser-induced fluorescence and the ground state energy levels were measured from the single vibronic level emission spectra. HBBr has an extensive band system in the red which involves a linear-bent transition between the two Renner-Teller components of what would be a ²Π state …

Required Biochem Class Live-Streamed This Summer: Collaboration With Union College Makes Required Credits Easier To Obtain, Chris Mclean-Wheeler

Andrews Agenda: Campus News

No abstract provided.

Identification Of Ecdysone Hormone Receptor Agonists As A Therapeutic Approach For Treating Filarial Infections, Amruta S Mhashilkar, Sai L Vankayala, Canhui Liu, Fiona Kearns, Priyanka Mehrotra, George Tzertzinis, Subba R Palli, H. Lee Woodcock Iii, Thomas R Unnasch

Chemistry Faculty Publications

BACKGROUND: A homologue of the ecdysone receptor has previously been identified in human filarial parasites. As the ecdysone receptor is not found in vertebrates, it and the regulatory pathways it controls represent attractive potential chemotherapeutic targets.

METHODOLOGY/ PRINCIPAL FINDINGS: Administration of 20-hydroxyecdysone to gerbils infected with B. malayi infective larvae disrupted their development to adult stage parasites. A stable mammalian cell line was created incorporating the B. malayi ecdysone receptor ligand-binding domain, its heterodimer partner and a secreted luciferase reporter in HEK293 cells. This was employed to screen a series of ecdysone agonist, identifying seven agonists active at sub-micromolar concentrations. …