Chemistry Commons^™

Characterization Of Α‑Synuclein Multimer Stoichiometry In Complex Biological Samples By Electrophoresis, Bryan A. Killinger, Anna Moszczynska

Pharmaceutical Sciences Faculty Publications

The aberrant aggregation of α-synuclein in the brain is a hallmark of Parkinson’s disease (PD). In vivo soluble α-synuclein occurs as a monomer and several multimers, the latter of which may be important for the biological function of α-synuclein. Currently, there is a lack of reproducible methods to compare α-synuclein multimer abundance between complex biological samples. Here we developed a method, termed “multimer-PAGE,” that combines in-gel chemical cross-linking with several common electrophoretic techniques to measure the stoichiometry of soluble α-synuclein multimers in brain tissue lysates. Results show that soluble α-synuclein from the rat brain exists as several high molecular weight …

Synthesis, Structural Characterization And Catalytic Activity Of Indenyl Tris-N-Pyrrolyl Phosphine Complexes Of Ruthenium, Matthew J. Stark, Michael J. Shaw, Nigam P. Rath, Eike B. Bauer

SIUE Faculty Research, Scholarship, and Creative Activity

The synthesis, characterization and catalytic activity of new ruthenium complexes of the tris-N-pyrrolyl phosphine ligand P(pyr)3 is described. The new ruthenium complexes [RuCl(ind)(PPh3){P(pyr)3}] and [RuCl(ind){P(pyr)3}2] (ind = indenyl ligand η5-C9H7−) were synthesized in 73% and 63% isolated yield, respectively, by thermal ligand exchange of [RuCl(ind)(PPh3)2] with P(pyr)3. The electronic and steric properties of the new complexes were studied through analysis of the X-Ray structures and through cyclic voltammetry. The new complexes [RuCl(ind)(PPh3){P(pyr)3}] and [RuCl(ind){P(pyr)3}2] and the known complex [RuCl(ind)(PPh3)2}] differed only slightly in their steric properties, as seen from the comparable bond lengths and angles around the ruthenium …

Restricted Mobility Of Specific Functional Groups Reduces Anti-Cancer Drug Activity In Healthy Cells, Murillo L. Martins, Rosanna Ignazzi, Juergen Eckert, Benjamin Watts, Ramon Kaneno, Willian F Zambuzzi, Luke Daemen, Margarida J Saeki, Heloisa N Bordallo

Chemistry Faculty Publications

The most common cancer treatments currently available are radio- and chemo-therapy. These therapies have, however, drawbacks, such as, the reduction in quality of life and the low efficiency of radiotherapy in cases of multiple metastases. To lessen these effects, we have encapsulated an anti-cancer drug into a biocompatible matrix. In-vitro assays indicate that this bio-nanocomposite is able to interact and cause morphological changes in cancer cells. Meanwhile, no alterations were observed in monocytes and fibroblasts, indicating that this system might carry the drug in living organisms with reduced clearance rate and toxicity. X-rays and neutrons were used to investigate the …

Sulfur-Mediated Photochemical Energy Harvesting In Nanoporous Carbons, Alicia Gomis-Berenguer, Mykola Seredych, Jesus Iniesta, Joao C. Lima, Teresa J. Bandosz, Conchi O. Ania

Publications and Research

This work provides new insights in the field of applied photochemistry based on semiconductor-free nanoporous carbons and its application to sunlight energy harvesting. Using carbon materials of increasing average pore size, chemical functionalization to introduce a variety of O- and S-containing functional groups and monochromatic light, we have shown the dependence of the photochemical conversion of phenol in the confinement of the carbons nanopore space with the wavelength of the irradiation source, the dimensions of the pore voids and their surface chemistry. The photochemical conversion of phenol inside the carbons pore space was found to be very sensitive to the …

Enhancement Of Supercapacitor Energy Storage By Leakage Reduction And Electrode Modification, Tete Tevi

USF Tampa Graduate Theses and Dissertations

Supercapacitors have emerged in recent years as a promising energy storage technology. The main mechanism of energy storage is based on electrostatic separation of charges in a region at the electrode-electrolyte interface called double layer. Various electrode materials including carbon and conducting polymers have been used in supercapacitors. Also, supercapacitors offer high life cycle and high power density among electrochemical energy storage devices. Despite their interesting features, supercapacitors present some disadvantages that limit their competitivity with other storage devices in some applications. One of those drawbacks is high self-discharge or leakage. The leakage occurs when electrons cross the double layer …

Xenoestrogens From Household Plastics Bind Estrogen Receptors And Affect Cell Proliferation, Susan G. Hurley, Brett R. Lackey, Patricia L. Tate, Sandra L. Gray

Journal of the South Carolina Academy of Science

Xenoestrogens are “foreign” chemicals or compounds that interact with estrogen receptors as either agonists or antagonists to interfere with endocrine system function. Xenoestrogens include phytoestrogens, pesticides, industrial by- products and synthetic estrogens. In this study, consumer plasticware, including baby bottles and food storage containers, were found to release xenoestrogenic compounds that bound to ERα and ERβ and affected cell proliferation.

High Temperature Electrochemical Engineering And Clean Energy Systems, Brenda L. Garcia-Diaz, Luke Olson, Michael Martinez-Rodriguez, Roderick Fuentes, Hector Colon-Mercado, Josh Gray

Journal of the South Carolina Academy of Science

Global power demand is projected to more than double by 2050 and meeting this increased power demand will require maintaining or increasing power output from all existing energy sources while adding a large amount of new capacity. The power sources that have the greatest opportunity to fulfill this demand gap over this time period are clean energy sources including solar and nuclear power. One of the areas of expertise that SRNL has been applying to help with a variety of clean energy technologies is in high temperature electrochemistry. Savannah River National Laboratory (SRNL) in collaboration with industrial and university partners …

A Ph Sensor For Non-Invasive In Vivo Detection And Imaging Of Implant Associated Infection, Unaiza Uzair, Donald Benza, Fenglin Wang, Yash Raval, Tzuen-Rong J. Tzeng, Jeffrey N. Anker

Chemistry Annual Research Symposium

We develop a pH sensor based on use of X-ray Excited Luminescence Chemical Imaging (XELCI) to non-invasively detect and image changes in pH of a surface with high spatial and pH resolution while minimizing tissue scattering effects. Diagnosis and treatment of infections associated with implanted medical devices is a challenge, as clinical symptoms of implant associated infection are often delayed and can sometimes be completely absent till infection reaches a later stage. Early diagnosis of implant associated infection and non-invasive continuous monitoring of infection to evaluate eradication and success of treatment has not been established yet. Treatment of implant infection …

Hydrothermal Single Crystal Growth And Characterization Of Novel Rare Earth Niobates And Tantalates: Lnnbo4 (Ln = La-Lu , Y), La2tao5(Oh) And Ln3ta2o9(Oh), Liurukara D. Sanjeewa, Kyle Fulle, Colin D. Mcmillen, Joseph W. Kolis

Chemistry Annual Research Symposium

Rare-earth niobates and tantalates are refractory materials that have been exploited in applications involving ion conductivity, photo-catalysis, and luminescence, both in doped and un-doped forms.

In general, refractory oxides have high melting points therefore synthesis of single crystals are more challenging. For example LnNbO4 can be grown readily by melt techniques such as Czochralski pulling ~1300 ˚C. However during the cooling crystal quality degraded resulting low quality crystals therefore high temperature melting techniques are not suitable for bulk single crystals growth.

Stability Of Copper(Ii) Complexes Of Sulfur And Selenium Antioxidants, Jaime M. Murphy, Brian A. Powell, Julia Brumaghim

Chemistry Annual Research Symposium

We focused on determining the stability constants for Cu(II) binding of sulfur and selenium antioxidants in aqueous conditions by potentiometric or spectrophotometric determination. Correlations of stability constant and antioxidant capability, as previously determined by gel electrophoresis, are examined, as well as the likelihood of each complex forming in vivo.

Understanding The Role Of Nadh In Cellular Fe2+ Generation Of Hydroxyl Radical And The Effects Of Polyphenol Antioxidants, Craig Goodman, Julia L. Brumaghim

Chemistry Annual Research Symposium

Structurally similar polyphenols have opposite effects on rates of Fe3+ reduction by NADH. In future work, we anticipate exploring several avenues:

What is the role of autoxidation? UV-vis kinetic experiments in an air-free atmosphere should reveal if MEGA is increasing the pool of reducible Fe3+.

What occurs in the presence of H2O2 and/or increased levels of NADH? Mimicking the environment of a stressed cell should yield interesting information about antioxidant activity if the rates change significantly.

Short F···F And F(Cl)···O Contacts In Fluoroorganic Crystals, And Short Ag···Ag And Ag···O Contacts In Silver Polyfluoroacetate Salts, Xiaolin Liu, Andrej V. Matsnev, Steven P. Belina, Colin D. Mcmillen, Joseph S. Thrasher

Chemistry Annual Research Symposium

The compound 2,2,5,5-tetrafluoro-2,5-dihydrofuran (1) [1] has been synthesized as a candidate monomer for synthesizing amorphous fluoropolymers in our research laboratory. Meanwhile, several crystal structures of products resulting from either new or existing chemistry of this cyclic ether have been solved and will be reported herein. The structures of the tricyclic ether 4 [2], resulting from the photodimerization of 1 in the presence of dry air, as well as perfluorooxodiacetic acid, resulting from the ring-opening oxidation of 1 [3], show a variety of short H···F, F···F, and O···F interactions. The crystal structure of 1,1,2,2,3,3,4,4-octafluorobutane-1,4-disulfonyl dichloride (ODD) reveals not only short F···F …

Surface Functionalized Nylon Capillary-Channeled Polymer (C-Cp) Fibers For Protein Ion-Exchange Separations, Liuwei Jiang, R. Kenneth Marcus

Chemistry Annual Research Symposium

Native nylon C-CP fibers have a very low density (~20 μmol g-1) of carboxylic acid groups that limits its performance on protein separations. To overcome this challenge, surface modification was done on native nylon fibers by grafting monomer ligands (acrylics) via microwave-assisted free radical polymerization.

Recent Advances In The Synthesis And Application Of Sf5-Containing Organic Compounds, Andrej V. Matsnev, Steven P. Belina, Si-Yan Qing, Kyle A. Berger, Anthony R. Scavuzzo, Piotr Dudzinski, Anna-Lena Dreier, Günter Haufe, Joseph S. Thrasher

Chemistry Annual Research Symposium

It is well known that fluorinated molecules play an important role in daily life. For example, organic molecules bearing either a fluorine atom itself or a short polyfluorinated substituent such as mono-, difluoro-, and trifluoromethyl groups, or pentafluoroethyl and perfluoropropyl groups are already widely used in medicinal and agricultural chemistry. In contrast, molecules with long perfluorinated chains have found vast application in materials science. Among the fluorine-containing moieties, the pentafluorosulfanyl (SF5) substituent occupies a special place.1 The pentafluorosulfanyl group brings unique properties to organic compounds and often improves their biological activities due to the group’s high chemical and metabolic stability, …

Development And Application Of Cu-Modified Carbon Electrodes From Pyrolyzed Paper Strips, Gema M. Durán, Tomás E. Benavidez, Jason Giuliani, Ángel Ríos, Carlos D. Garcia

Chemistry Annual Research Symposium

A one-step approach for the synthesis and integration of copper nanoparticles (CuNPs) onto paper-based carbon electrodes is herein reported. The method is based on the pyrolysis (1000 ºC under a mixture of 95% Ar / 5% H2 for 1 hour) of paper strips modified with a saturated solution of CuSO4 and yields to the formation of abundant CuNPs on the surface of carbonized cellulose fibers. The resulting substrates were characterized by a combination of scanning electron microscopy, EDX, Raman spectroscopy as well as electrical and electrochemical techniques. Their potential application, as working electrodes for non-enzymatic amperometric determination of glucose, was …

A Smart Polymer Hydrogel As A Chemical Sensor On Biomedical Implant, Md Arifuzzaman, Caleb Behrend, John Desjardins, Jeffrey N. Anker

Chemistry Annual Research Symposium

Orthopedic implants are manufactured to support on healing fractured bones. In United States, over 2 million fracture fixation devices, including intra-medullary nails, external fixation pins, plates, and screws, and over 600 thousands joint prostheses, are implanted in patients annually. While fairly common, these fixation surgeries (5%) sometimes lead to unavoidable infection, which only amplifies health care costs accumulated from the initial procedures. In most cases, bacterial biofilms acutely causes infection which is a major reason of medical device failure. In order to obtain proper infections detection around biomedical implants a non-invasive chemical sensor is required. In vivo detection of low …

Electrochemically-Preadsorbed Collagen Promotes Adult Human Mesenchymal Stem Cell Adhesion On Carbon Nanostructured Substrates, Tomás E. Benavidez, Marissa E. Wechsler, Madeleine M. Farrer, Rena Bizios, Carlos D. Garcia

Chemistry Annual Research Symposium

The effect of electric potential on the adsorption of collagen type I onto optically transparent carbon electrodes (OTCE) and its mediation on subsequent adhesion of adult, human, mesenchymal stem cells (hMSCs) is described. Adsorption was investigated as a function of the protein concentration and applied potential. The resulting substrate surfaces were characterized using spectroscopic ellipsometry (SE), atomic force microscopy (AFM), and cyclic voltammetry (CV). While the higher applied potential and protein concentration, the higher the adsorbed amount, the application of potential values higher than +800 mV resulted in the oxidation of the adsorbed protein. Subsequent adhesion of hMSCs on the …

Liquid Sampling-Atmospheric Pressure Glow Discharge Ion Source For Nonproliferation Of Nuclear Material, Edward Hoegg, R. Kenneth Marcus, Charles Barinaga, George Hager, David Koppenaal, Garret Hart

Chemistry Annual Research Symposium

An area of continuing intense interest has been the development of portable or fieldable (man-portable, luggable, or transportable) analytical instrumentation. One specific driver for portable or fieldable analytical instrumentation are the needs of the nuclear safeguards community for versatile, easy-to-use, in-field mass spectrometer systems for determining the 235U/238U isotope ratios in UF6 at enrichment facilities. In order to meet this demand the authors propose using a liquid sampling-atmospheric pressure glow discharge (LS-APGD) ion source, Fig 1.1-3 The LS-APGD was optimized for isotope ratio analysis to have a liquid flow rate of 30 uL min-1 a gas flow rate of 0.5 …

Investigation Of Ionic And Electronic Conductivities In Modified Carbon/Zirconia Composites, Jamie A. Shetzline, Jung-Min Oh, Stephen E. Creager

Chemistry Annual Research Symposium

Ionic and electronic conductivities were recently shown to be able to be independently probed utilizing a near-DC based method for free standing thin films containing mixtures of nafion and carbon black. Recently the mixed conductivity methodology was extended to packed powders in order to study ionic and electronic conductivities of carbon/zirconia nano composite materials for which molecular and polymer electrolytes were covalently grafted onto the carbon/zirconia particle surfaces. The method relies upon careful control of the nature of the contact between the sample and the current-carry-ing electrodes, as well as the geometry of the sample configuration.

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.

Human Insulin Adsorption To Monolayer Graphene. A Molecular Dynamics Study., Richard Overstreet, Brian Dominy

Chemistry Annual Research Symposium

Molecular dynamics simulations were conducted using the CHARMM22 potential and TIP3P solvent to model human insulin adsorption to graphene. TIP3P explicit solvent was used to capture the hydrophobic effect, the mechanism responsible for the adsorption of proteins to hydrophobic surfaces. This water model was originally parameterized for the CHARMM22 potential and amino acid residues thus it was required to develop Lennard-Jones graphene carbon parameters to reproduce the empirical water graphite contact angle of 86 degrees. Adsorption was modeled with three different orientations about the graphene monolayer. Insulin shows varying degrees of adsorption surface area and correlated binding affinity due to …

Fast Production Of Microfluidic Devices By Co2 Laser Engraving Of Wax-Coated Glass Slides, Eric T. Da Costa, Mauro F.S. Santos, Hong Jiao, Claudimir L. Do Lago, Ivano G.R. Gutz, Carlos D. Garcia

Chemistry Annual Research Symposium

Glass is one of the most convenient materials for the development of microfluidic devices. However, most of the fabrication protocols, require long processing times and expensive facilities. Polymeric materials have been extensively used due to the fast and low-cost production methods. Ablation by CO2 laser has been used to prototype on polymeric materials, but is difficult to extend to glass devices, because the local heating causes surface cracking. We herein describe a simple procedure to produce microfluidic devices for capillary electrophoresis from microscope glass slides.

Uplc–Qtof–Ms And Nmr Analyses Of Graviola (Annona Muricata) Leaves, Ingrid De Moraes, Paulo Ribeiro, Flávio Schmidt, Kirley Canuto, Guilherme Zocolo, Edy De Brito, Rensheng Luo, Kristy Richards, Kevin Tran, Robert Smith

Chemistry & Biochemistry Faculty Works

No abstract provided.

In Silico Model For Naatm1 Type Atp Binding Cassette Exporter Conformational Transitions, Yinling Liu, Brian N. Dominy

Chemistry Annual Research Symposium

No abstract provided.

Creation Of A New Type Of Ion Exchange Material For Rapid, High-Capacity, Reversible And Selective Ion Exchange Without Swelling And Entrainment, Baiyan Li, Yiming Zhang, Dingxuan Ma, Zhenyu Xing, Tianliang Ma, Zhan Shi, Xiulei Ji, Shengqian Ma

Chemistry Faculty Publications

Ion-exchange materials, currently dominated by resins, are widely used in a plethora of areas. However, the drawbacks of conventional resins necessitate the creation of a new model of ion exchange materials that feature controllable swelling, easily accessible ion exchange sites, high ion exchange capacity, fast ion exchange kinetics, and high chemical stability as illustrated herein in the context of functionalizing a porous organic polymer (POP) with ion exchange groups. The advantages of POP-based ion exchange materials in comparison with conventional resins and other types of ion exchange materials have been highlighted through an evaluation of their performances in scavenging precious …

Development And Application Of New Solid-State Models For Low-Energy Vibrations, Lattice Defects, Entropies Of Mixing, And Magnetic Properties, Jacob M. Schliesser

Theses and Dissertations

Low-temperature heat capacity data contain information on the physical properties of materials, and new models continue to be developed to aid in the analysis and interpretation of heat capacity data into physically meaningful properties. This work presents the development of two such models and their application to real material systems. Equations describing low-energy vibrational modes with a gap in the density of states (DOS) have been derived and tested on several material systems with known gaps in the DOS, and the origins of such gaps in the DOS are presented. Lattice vacancies have been shown to produce a two-level system …

The Subject Librarian Newsletter, Chemistry, Spring 2016, Patti Mccall

Libraries' Newsletters

No abstract provided.

Molecular Scale Cure Rate Dependence Of Thermoset Matrix Polymers, Christopher Harold Childers, Mohammad K. Hassan, Kenneth A. Mauritz, Jeffrey S. Wiggins

Faculty Publications

This manuscript demonstrates the molecular scale cure rate dependence of di-functional epoxide based thermoset polymers cured with amines. A series of cure heating ramp rates were used to determine the influence of ramp rate on the glass transition temperature (Tg) and sub-Tg transitions and the average free volume hole size in these systems. The networks were comprised of 3,3′-diaminodiphenyl sulfone (33DDS) and diglycidyl ether of bisphenol F (DGEBF) and were cured at ramp rates ranging from 0.5 to 20 °C/min. Differential scanning calorimetry (DSC) and NIR spectroscopy were used to explore the cure ramp rate dependence of the polymer network …

Ion Clustering In Aqueous Salt Solutions Near The Liquid/Vapor Interface, Smith J. D., Steven W. Rick

Chemistry Faculty Publications

Molecular dynamics simulations of aqueous NaCl, KCl, NaI, and KI solutions are used to study the effects of salts on the properties of the liquid/vapor interface. The simulations use the models which include both charge transfer and polarization effects. Pairing and the formation of larger ion clusters occurs both in the bulk and surface region, with a decreased tendency to form larger clusters near the interface. An analysis of the roughness of the surface reveals that the chloride salts, which have less tendency to be near the surface, have a roughness that is less than pure water, while the iodide …

Polymer Chain Dynamics In Epoxy Based Composites As Investigated By Broadband Dielectric Spectroscopy, Mohammad K. Hassan, Samuel James Tucker, Ahmed Abukmail, Jeffrey S. Wiggins, Kenneth A. Mauritz

Faculty Publications

Epoxy networks of the diglycidyl ether of bisphenol A (DGEBA) were prepared using 3,3′- and 4,4′-diaminodiphenyl sulfone isomer crosslinkers. Secondary relaxations and the glass transitions of resultant networks were probed using broadband dielectric spectroscopy (BDS). A sub-T_g γ relaxation peak for both networks shifts to higher frequencies (f) with increasing temperature in Arrhenius fashion, both processes having the same activation energy and being assigned to phenyl ring flipping in DGEBA chains. A β relaxation is assigned to local motions of dipoles that were created during crosslinking reactions. 4,4′-based networks exhibited higher T_g relative to 3,3′-based …