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Physical Sciences and Mathematics Commons

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Chemistry

The University of Southern Mississippi

Faculty Publications

2011

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Preparation Of Novel Hydrolyzing Urethane Modified Thiol-Ene Networks, Nicole M. Mackey, Bridget S. Confait, James Wynne, J. Paige Buchanan Oct 2011

Preparation Of Novel Hydrolyzing Urethane Modified Thiol-Ene Networks, Nicole M. Mackey, Bridget S. Confait, James Wynne, J. Paige Buchanan

Faculty Publications

Novel tetra-functional hydrolyzing monomers were prepared from the reaction of TEOS and select alkene-containing alcohols, ethylene glycol vinyl ether or 2-allyloxy ethanol, and combined with trimethylolpropane tris(3-mercaptopropionate) (tri-thiol) in a thiol-ene “click” polymerization reaction to produce clear, colorless thiol-ene networks using both radiation and thermal-cure techniques. These networks were characterized for various mechanical characteristics, and found to posses Tg’s (DSC), hardness, tack, and thermal stability (TGA) consistent with their molecular structures. A new ene-modified urethane oligomer was prepared based on the aliphatic polyisocyanate Desmodur® N 3600 and added to the thiol-ene hydrolyzable network series in increasing amounts, …


A Modified Stokes-Einstein Equation For A Beta Aggregation, Srisairam Achuthan, Bong Jae Chung, Preetam Ghosh, Vijayaraghavan Rangachari, Ashwin Vaidya Oct 2011

A Modified Stokes-Einstein Equation For A Beta Aggregation, Srisairam Achuthan, Bong Jae Chung, Preetam Ghosh, Vijayaraghavan Rangachari, Ashwin Vaidya

Faculty Publications

Background: In all amyloid diseases, protein aggregates have been implicated fully or partly, in the etiology of the disease. Due to their significance in human pathologies, there have been unprecedented efforts towards physiochemical understanding of aggregation and amyloid formation over the last two decades. An important relation from which hydrodynamic radii of the aggregate is routinely measured is the classic Stokes-Einstein equation. Here, we report a modification in the classical Stokes-Einstein equation using a mixture theory approach, in order to accommodate the changes in viscosity of the solvent due to the changes in solute size and shape, to implement a …


Thiolene-Based Microfluidic Flow Cells For Surface Plasmon Resonance Imaging, Gareth Sheppard, Takao Oseki, Akira Baba, Derek L. Patton, Futao Kaneko, Leidong Mao, Jason Locklin Jun 2011

Thiolene-Based Microfluidic Flow Cells For Surface Plasmon Resonance Imaging, Gareth Sheppard, Takao Oseki, Akira Baba, Derek L. Patton, Futao Kaneko, Leidong Mao, Jason Locklin

Faculty Publications

Thiolene-based microfluidic devices have been coupled with surface plasmon resonance imaging (SPRI) to provide an integrated platform to study interfacial interactions in both aqueous and organic solutions. In this work, we develop a photolithographic method that interfaces commercially available thiolene resin to gold and glass substrates to generate microfluidic channels with excellent adhesion that leave the underlying sensor surface free from contamination and readily available for surface modification through self-assembly. These devices can sustain high flow rates and have excellent solvent compatibility even with several organic solvents. To demonstrate the versatility of these devices, we have conducted nanomolar detection of …


Non-Esterified Fatty Acids Generate Distinct Low-Molecular Weight Amyloid-Β (Aβ42) Oligomers Along Pathway Different From Fibril Formation, Amit Kumar, Rebekah L. Bullard, Pritesh Patel, Lea C. Paslay, Dipti Singh, Ewa A. Bienkiewicz, Sarah E. Morgan, Vijayaraghavan Rangachari Apr 2011

Non-Esterified Fatty Acids Generate Distinct Low-Molecular Weight Amyloid-Β (Aβ42) Oligomers Along Pathway Different From Fibril Formation, Amit Kumar, Rebekah L. Bullard, Pritesh Patel, Lea C. Paslay, Dipti Singh, Ewa A. Bienkiewicz, Sarah E. Morgan, Vijayaraghavan Rangachari

Faculty Publications

Amyloid-beta (A beta) peptide aggregation is known to play a central role in the etiology of Alzheimer's disease (AD). Among various aggregates, low-molecular weight soluble oligomers of A beta are increasingly believed to be the primary neurotoxic agents responsible for memory impairment. Anionic interfaces are known to influence the A beta aggregation process significantly. Here, we report the effects of interfaces formed by medium-chain (C9-C12), saturated non-esterified fatty acids (NEFAs) on A beta 42 aggregation. NEFAs uniquely affected A beta 42 aggregation rates that depended on both the ratio of A beta:NEFA as well the critical micelle concentration (CMC) of …


Thiol-Yne 'Click' Chemistry As A Route To Functional Lipid Mimetics, Sandeep S. Naik, Justin W. Chan, Christopher Comer, Charles E. Hoyle, Daniel A. Savin Jan 2011

Thiol-Yne 'Click' Chemistry As A Route To Functional Lipid Mimetics, Sandeep S. Naik, Justin W. Chan, Christopher Comer, Charles E. Hoyle, Daniel A. Savin

Faculty Publications

Thiol-alkyne 'click' chemistry is a modular, efficient mechanism to synthesize complex A2B 3-arm star polymers. This general motif is similar to a phospholipid where the A blocks correspond to lypophilic chains and the B block represents the polar head group. In this communication we employ thiol-yne chemistry to produce polypeptide-based A2B lipid mimetics. The utility of the thiol-yne reaction is demonstrated by using a divergent and a convergent approach in the synthesis. These polymers self-assemble in aqueous solution into spherical vesicles with a relatively narrow size distribution independent of block composition over the range studied. Using …