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Chemistry

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The University of Southern Mississippi

Faculty Publications

2004

Articles 1 - 4 of 4

Full-Text Articles in Physical Sciences and Mathematics

Radical Initiated Polymerization In A Bifunctional Mixture Via Computer Simulation, Keri L. Diamond, Ras B. Pandey, Shelby F. Thames Jun 2004

Radical Initiated Polymerization In A Bifunctional Mixture Via Computer Simulation, Keri L. Diamond, Ras B. Pandey, Shelby F. Thames

Faculty Publications

Computer simulations are performed to study the polymerization behavior in a mixture of bifunctional groups such as olefins (A) and acrylates (B) in an effective solvent (a coarse description for vegetable oil derived macromonomers (VOMMs) in solution) on a cubic lattice. A set of interactions between these units and solvent (S) constituents and their relative concentrations (p(A), p(B), and p(S)) are considered. Samples are equilibrated with Metropolis algorithm to model the perceived behavior of VOMMs. The covalent bonding between monomeric units is then implemented via reaction pathways initiated by stochastic motion of free radicals (a very small fraction). The rate …


Binary Frontal Polymerization: Velocity Dependence On Initial Composition, John A. Pojman, Jerry A. Griffith, H. Archie Nichols Mar 2004

Binary Frontal Polymerization: Velocity Dependence On Initial Composition, John A. Pojman, Jerry A. Griffith, H. Archie Nichols

Faculty Publications

Frontal polymerization is a mode of polymerization in which a localized zone of reaction propagates through the coupling of thermal diffusion and the Arrhenius dependence of the reaction rate. The dependence of the front propagation velocity on the initial composition has been determined in initially miscible binary systems of a free-radically cured diacrylate and an amine- or cationically cured epoxy resin. A minimum of the velocity as a function of the monomer mole fraction is observed if the two polymerizations occur independently. Excellent agreement with an analytical description was found with the diacrylate and an amine-cured epoxy but not for …


Human Glutaminyl Cyclase And Bacterial Zinc Aminopeptidase Share A Common Fold And Active Site, Rachell E. Booth, Simon C. Lovell, Stephanie A. Misquitta, Robert C. Bateman Jr. Feb 2004

Human Glutaminyl Cyclase And Bacterial Zinc Aminopeptidase Share A Common Fold And Active Site, Rachell E. Booth, Simon C. Lovell, Stephanie A. Misquitta, Robert C. Bateman Jr.

Faculty Publications

Background: Glutaminyl cyclase (QC) forms the pyroglutamyl residue at the amino terminus of numerous secretory peptides and proteins. We previously proposed the mammalian QC has some features in common with zinc aminopeptidases. We now have generated a structural model for human QC based on the aminopeptidase fold (pdb code 1AMP) and mutated the apparent active site residues to assess their role in QC catalysis.

Results: The structural model proposed here for human QC, deposited in the protein databank as 1MOI, is supported by a variety of fold prediction programs, by the circular dichroism spectrum, and by the presence …


Superior 5' Homogeneity Of Rna From Atp-Initiated Transcription Under The T7 Φ2.5 Promoter, Tricia M. Coleman, Guocan Wang, Faqing Huang Jan 2004

Superior 5' Homogeneity Of Rna From Atp-Initiated Transcription Under The T7 Φ2.5 Promoter, Tricia M. Coleman, Guocan Wang, Faqing Huang

Faculty Publications

Transcription from the commonly used GTP- initiating T7 class III promoter phi6.5 frequently produces heterogeneous RNA at both 3' and 5' ends. We demonstrate here that RNA transcripts from the T7 class II promoter phi2.5 have superior 5' homogeneity over those from the phi6.5 promoter, with comparable total RNA yields. The overall homogeneity of RNA transcripts is improved to different degrees depending on RNA sequences, although transcription under phi2.5 does not affect the 3' heterogeneity of RNA. In combination with 3' RNA trimming by DNAzymes or ribozymes, this ATP- initiated transcription system based on the T7 phi2.5 promoter can provide …