Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons

Open Access. Powered by Scholars. Published by Universities.®

2009

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 421 - 450 of 823

Full-Text Articles in Chemistry

Chiroptical Fluorescent Sensors For Mercury, Collaborative Project Jan 2009

Chiroptical Fluorescent Sensors For Mercury, Collaborative Project

Dyson College- Seidenberg School of CSIS : Collaborative Projects and Presentations

This entry adheres to the use of the quad chart template to provide a succint description only of the current research project undertaken by the participants. It provides for the following information

1. Participants and Affiliations
2. Overall Project Goals
3. Illustrative picture
4. Specific research/artistic/pedagogic foci


Gec1-Kappa Opioid Receptor Binding Involves Hydrophobic Interactions Gec1 Has Chaperone-Like Effect, Yong Chen, Chongguang Chen, Evangelia Kotsikorou, Diane L. Lynch, Patricia H. Reggio, Lee Yuan Liu-Chen Jan 2009

Gec1-Kappa Opioid Receptor Binding Involves Hydrophobic Interactions Gec1 Has Chaperone-Like Effect, Yong Chen, Chongguang Chen, Evangelia Kotsikorou, Diane L. Lynch, Patricia H. Reggio, Lee Yuan Liu-Chen

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

We demonstrated previously that the protein GEC1 (glandular epithelial cell 1) bound to the human κ opioid receptor (hKOPR) and promoted cell surface expression of the receptor by facilitating its trafficking along the secretory pathway. Here we showed that three hKOPR residues (Phe345, Pro346, and Met350) and seven GEC1 residues (Tyr49, Val51, Leu55, Thr56, Val57, Phe60, and Ile64) are indispensable for the interaction. Modeling studies revealed that the interaction was mediated via direct contacts between the kinked hydrophobic fragment in …


Total Synthesis Of (±)-Quebrachamine Via [3+2] Cycloaddition And Efficient Chloroacetamide Photocyclization, Brian Pagenkopf, Barbora Bajtos Jan 2009

Total Synthesis Of (±)-Quebrachamine Via [3+2] Cycloaddition And Efficient Chloroacetamide Photocyclization, Brian Pagenkopf, Barbora Bajtos

Chemistry Publications

The total synthesis of (±)-quebrachamine has been completed in 13 linear steps and 17.8 % overall yield. The indole core was constructed via a formal [3+2] dipolar cycloaddition between a functionalized nitrile and donor-acceptor cyclopropane, and the synthetically challenging nine-membered ring was secured by an efficient chloroacetamide photocyclization.


Monitoring Water Quality On Tributary Inflows To Lake Mead And On A Transect Of The Overton Arm, Jorge Arufe, Robert Burrows Jan 2009

Monitoring Water Quality On Tributary Inflows To Lake Mead And On A Transect Of The Overton Arm, Jorge Arufe, Robert Burrows

Lake Mead Science Symposium

The USGS, in cooperation with the NPS and BOR (Bureau of Reclamation), is collecting water quality data to determine the temporal changes and spatial distributions of natural and anthropogenic compounds entering the Overton Arm of Lake Mead. These efforts and others already underway on the lake by BOR, USGS, and SNWA will aid in the development of a reservoir model of the lake. The effects of the flood flows on the water quality of the Overton Arm are largely unknown and necessary for model development and verification.

Water quality physical parameters are continuously monitored near the mouth of the Virgin …


Comparison Of Polarization Consistent And Correlation Consistent Basis Sets For Noncovalent Interactions, Adel M. Elsohly, Gregory S. Tschumper Jan 2009

Comparison Of Polarization Consistent And Correlation Consistent Basis Sets For Noncovalent Interactions, Adel M. Elsohly, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

The convergence of the polarization consistent family of basis sets to the MP2 complete basis set (CBS) limit has been examined for the dissociation energies of five weakly bound clusters: (HF)2, (HF)3, (H2O)2, (H2O)3, and (C2H2)2. MP2 results obtained with two series of polarization consistent basis sets and the analogous series of Dunning's correlation consistent basis sets are compared to the CBS limits obtained with the explicitly correlated MP2-R12 method. Although the polarization consistent basis sets do converge systematically to the CBS …


Asymmetric Synthesis Of 1,2-Dioxanes: Approaches To The Peroxyplakoric Acids, Chunping Xu, Chris Schwartz, Joseph Raible, Patrick Dussault Jan 2009

Asymmetric Synthesis Of 1,2-Dioxanes: Approaches To The Peroxyplakoric Acids, Chunping Xu, Chris Schwartz, Joseph Raible, Patrick Dussault

Patrick Dussault Publications

The stereospecific intramolecular alkylation of a hydroperoxyacetal provides the basis for the first asymmetric synthesis of the dioxane propionate core of the peroxyplakorates. Chemoselective hydrometallation of an alkyne in the presence of a peroxide is used to introduce a synthon for the polyunsaturated side chains of the peroxyplakorates. The route suggests a general solution for the 1,2-dioxane unit in many peroxide natural products.


Development Of Novel Dart Tofms Analytical Techniques For The Identification Of Organic Contamination On Spaceflight-Related Substrates And Aqueous Media, Kathleen Loftin Jan 2009

Development Of Novel Dart Tofms Analytical Techniques For The Identification Of Organic Contamination On Spaceflight-Related Substrates And Aqueous Media, Kathleen Loftin

Electronic Theses and Dissertations

Organic contamination on spaceflight hardware is an ongoing concern for spaceflight safety. In addition, for the goal of analyzing for possible evidence of extra-terrestrial life, it is necessary to consider the presence of terrestrial contamination. This paper will introduce and evaluate a new method using a direct analysis real time (DART) ionization source paired with a high resolution time of flight mass spectrometer (TOFMS) for the determination of organic contamination involved in spaceflight hardware and ground support materials. This novel analytical technique has significant advantages over current methodologies. Materials analyzed in this study were historically considered as probable contaminants in …


Poly(Styrene-Co-Vinylbenzylchloride-Co-Divinylbenzene) Coated Iron Oxide: Synthesis And Effects On Size And Morphology, M. D. Shultz, J. R. Marin, S. H. Naik, J. Wilkins, J. M. Laza, J. L. Vilas, M. Rodriguez, N. Perez, E. E. Carpenter Jan 2009

Poly(Styrene-Co-Vinylbenzylchloride-Co-Divinylbenzene) Coated Iron Oxide: Synthesis And Effects On Size And Morphology, M. D. Shultz, J. R. Marin, S. H. Naik, J. Wilkins, J. M. Laza, J. L. Vilas, M. Rodriguez, N. Perez, E. E. Carpenter

Chemistry Publications

Iron oxide nanoparticles were coated with a polymer synthesized from the monomers of styrene, divinylbenzene, and vinylbenzylchloride. The resultant polymer microspheres from synthesis without nanoparticle loading are primarily monodispersed with a diameter of 3.45 μm as measured by scanning electron microscopy. The addition of 1% nanoparticles by mass appears to decrease the size of the microspheres down to 2.04 μm as well as increase the polydispersity. This trend is also seen to continue as you add more nanoparticles to the system going from 3.45 μm with 0% nanoparticles down to below 1 μm for 5% nanoparticles. This indicates that the …


Dispersal And Establishment Both Limit Colonization During Primary Succession On A Glacier Foreland, Chad C. Jones, Roger Del Moral Jan 2009

Dispersal And Establishment Both Limit Colonization During Primary Succession On A Glacier Foreland, Chad C. Jones, Roger Del Moral

Botany Faculty Publications

Plant colonization can be limited by lack of seeds or by factors that reduce establishment. The role of seed limitation in community assembly is being increasingly recognized, but in early primary succession, establishment failure is still considered more important. We studied the factors limiting colonization on the foreland of Coleman Glacier, Washington, USA to determine the importance of seed and establishment limitation during primary succession. We also evaluated the effects of seed predation, drought and existing vegetation on establishment. We planted seeds of seven species into plots of four different ages and found evidence that both seed and establishment limitation …


Structure Of Human Dna Polymerase Κ Inserting Datp Opposite An 8-Oxog Dna Lesion, Rodrigo Vasquez-Del Carpio, Timothy D. Silverstein, Samer Lone, Michael K. Swan, Jayati R. Choudhury, Robert E. Johnson, Satya Prakash, Louise Prakash, Aneel K. Aggarwal Jan 2009

Structure Of Human Dna Polymerase Κ Inserting Datp Opposite An 8-Oxog Dna Lesion, Rodrigo Vasquez-Del Carpio, Timothy D. Silverstein, Samer Lone, Michael K. Swan, Jayati R. Choudhury, Robert E. Johnson, Satya Prakash, Louise Prakash, Aneel K. Aggarwal

Chemical Sciences Faculty Publications

Background: Oxygen-free radicals formed during normal aerobic cellular metabolism attack bases in DNA and 7,8-dihydro-8-oxoguanine (8-oxoG) is one of the major lesions formed. It is amongst the most mutagenic lesions in cells because of its dual coding potential, wherein 8-oxoG(syn) can pair with an A in addition to normal base pairing of 8-oxoG(anti) with a C. Human DNA polymerase κ (Polκ) is a member of the newly discovered Y-family of DNA polymerases that possess the ability to replicate through DNA lesions. To understand the basis of Polκ's preference for insertion of an A opposite 8-oxoG lesion, …


Using The Morse Potential To Understand Reaction Coördinates Using Maple, Carl W. David Jan 2009

Using The Morse Potential To Understand Reaction Coördinates Using Maple, Carl W. David

Chemistry Education Materials

The interactions employed in the “linear” reaction A(g)+BC(g) -> AB(g) + C(g) in a “one dimensional world” can be used to illustrate the “reaction coördinate”, using Maple, in a manner which allows students to inspect potential energy surfaces, make contour maps of those surfaces, and conceptually construct the “reaction coördinate” by tracing the local minimum path on the surface created.“one dimensional world” can be used to illustrate the “reaction coördinate”, using Maple, in a manner which allows students to inspect potential energy surfaces, make contour maps of those surfaces, and conceptually construct the “reaction coördinate” by tracing the local minimum …


Frobenius Solution For Legendre's Equation, Rodrigue's Formula And Normalization, Carl W. David Jan 2009

Frobenius Solution For Legendre's Equation, Rodrigue's Formula And Normalization, Carl W. David

Chemistry Education Materials

The Frobenius solution to Legendre/s equation is developed in detail as is Rodrigue's formula, which is employed to normalize Legendre polynomials.


1s_A 1s_B Overlap Integrals, Analytic And Maple Approches, Carl W. David Jan 2009

1s_A 1s_B Overlap Integrals, Analytic And Maple Approches, Carl W. David

Chemistry Education Materials

The calculation of overlap between adjacent orbitals (not on the same center) requires a slight facility with calculus which is quite instructive. That calculation is presented here.


Rationale For Studying Physical Chemistry, Carl W. David Jan 2009

Rationale For Studying Physical Chemistry, Carl W. David

Chemistry Education Materials

The various rationales for studying physical chemistry, and specifically the theoretical component thereof are presented in what is hoped in a coherent package.


The Harmonic Oscillator's Frobenius Solution, Carl W. David Jan 2009

The Harmonic Oscillator's Frobenius Solution, Carl W. David

Chemistry Education Materials

The Frobenius solution to the differential equations associated with the harmonic oscillator (QM) is carried out in detail.


The Hartree-Fock Method Applied To Helium's Electrons, Carl W. David Jan 2009

The Hartree-Fock Method Applied To Helium's Electrons, Carl W. David

Chemistry Education Materials

The difficulties of applying the Hartree-Fock method to many body problems is illustrated by treating Helium's electrons up to the point where tractability vanishes. Second, the problem of applying Hartree-Fock methods to the helium atom's electrons, when they are constrained to remain on a sphere, is revisited. The 6-dimensional total energy operator is reduced to a 2-dimensional one, and the application of that 2-dimensional operator in the Hartree-Fock mode is discussed.


Multiple-Choice Testing In Science And Technology Courses, Carl W. David Jan 2009

Multiple-Choice Testing In Science And Technology Courses, Carl W. David

Chemistry Education Materials

Wide spread and continuing use of multiple-choice testing in technical subjects is leading to a mindset amongst students which is antithetical with actual use of intellect.


L'Hopital's Rule In Chemistry: Irreversible Morphing Into Reversible Isothermal Expansions, Carl W. David Jan 2009

L'Hopital's Rule In Chemistry: Irreversible Morphing Into Reversible Isothermal Expansions, Carl W. David

Chemistry Education Materials

L'Hopital's Rule is discussed in the cvase of an irreversible isothermal expansion.


Mo Visualization Of Pi Orbitals, Carl W. David Jan 2009

Mo Visualization Of Pi Orbitals, Carl W. David

Chemistry Education Materials

In the spirit of trying to convert people to understanding atomic orbitals centered elsewhere than the origin, we continue the discussion of visualizing molecular orbitals, so called LCAO-MO, using various plotting tricks in Maple.


A Review Of Helium Hamiltonians, Carl W. David Jan 2009

A Review Of Helium Hamiltonians, Carl W. David

Chemistry Education Materials

Helium Hamiltonian transformations are discussed in extreme detail.


Lee O Case's "Elements Of The Phase Rule", Introduction And Explanation, Carl W. David Jan 2009

Lee O Case's "Elements Of The Phase Rule", Introduction And Explanation, Carl W. David

Chemistry Education Materials

This out of print 1939 manuscript, updated, is added to the literature with slight additions


The Runge0lenz Vector (Continued), Carl W. David Jan 2009

The Runge0lenz Vector (Continued), Carl W. David

Chemistry Education Materials

We continue our discussion of the Runge-Lenz vector in a quantum mechanical context. The traditional form of the Runge-Lenz vector is obtained, and the commutation relations between the Runge-Lenz vector, the Hamiltonian, and the Angular Momentum are obtained using Maple.


Lee O Case's "Elements Of The Phase Rule", Chapter 2, Carl W. David Jan 2009

Lee O Case's "Elements Of The Phase Rule", Chapter 2, Carl W. David

Chemistry Education Materials

The second chapter of the Case text on the phase rule, this time dealing with two component systems, added to by the author, is presented here.


Structural Investigation Of The Complex Of Filamin A Repeat 21 With Integrin Αiib And Β3 Cytoplasmic Tails – A Potential “Transmission” To Regulate Cell Migration, Jianmin Liu Jan 2009

Structural Investigation Of The Complex Of Filamin A Repeat 21 With Integrin Αiib And Β3 Cytoplasmic Tails – A Potential “Transmission” To Regulate Cell Migration, Jianmin Liu

ETD Archive

Cell functions in multi-cellular organisms are strongly depend on the dynamic cooperation between cell adhesion and cytoskeleton reorganization. Integrins, the major cell adhesion receptors, bind to extracellular matrix (ECM) and soluble ligands on the cell surface and link to the actin cytoskeleton inside the cell membrane. In this manner, integrins integrate cell adhesion and cytoskeleton reorganization by acting as a mechanical force transducer and a biochemical signaling hub (Zamir and Geiger 2001). Consequently, integrins are vital for development, immune responses, leukocyte traffic and hemostasis, and a variety of other cellular and physiological processes. Integrins are also are the focal point …


Hemeproteins Bathed In Ionic Liquids;Examining The Role Of Water And Protons In Redox Behavior And Catalytic Function, John Joseph Moran Jan 2009

Hemeproteins Bathed In Ionic Liquids;Examining The Role Of Water And Protons In Redox Behavior And Catalytic Function, John Joseph Moran

ETD Archive

We investigate the changing behaviors of myoglobin and nitric oxide synthase (NOS) in the near-absence of bulk water and/or protons by using ionic liquid butyl methyl imidazolium tetrafluoroborate as a non-aqueous milieu. Through direct charge transfer and metalloprotein-mediated catalytic reduction of oxygen and nitric oxide, we shed light on diverging aspects on how the two hemeproteins face the scarcity of water and/or protons in bulk. Isotopic effect investigations using D2O further elucidates kinetic aspects of proton transfer. Finally, in the case of NOS oxygenase, pterin cofactor binding and NOS-mediated catalytic oxidation of L-arginine in ionic liquids interrogates proton and water …


Fabricating New Miniaturized Biosensors For The Detection Of Dna Damage And Dna Mismatches, N. Indika Perera Jan 2009

Fabricating New Miniaturized Biosensors For The Detection Of Dna Damage And Dna Mismatches, N. Indika Perera

ETD Archive

A large number of genetic diseases and genetic disorders are simply caused by base alterations in the genome. Therefore, developing efficient and cost effective techniques for routine detection of these alterations is of great importance. Different methods involving gel electrophoresis and Polymerase Chain Reaction have been widely employed, but majority of these methods are costly, time consuming, and lack throughput, creating a fundamental gap between the current state-of-the-art and desired characteristics of low-cost, high-speed, simplicity, versatility, and potential for miniaturization. In this study, we attempt to bridge this gap by developing new sensing platforms to detect DNA base mismatches and …


Nitric Oxide Synthase In Confined Environments;Detection And Quantification Of Nitric Oxide Released From Cells And Modified Liposomes Using A Sensitive Metal Catalyst-Pedot Modified Carbon Fiber Electrode, P. A. Reshani H. Perera Jan 2009

Nitric Oxide Synthase In Confined Environments;Detection And Quantification Of Nitric Oxide Released From Cells And Modified Liposomes Using A Sensitive Metal Catalyst-Pedot Modified Carbon Fiber Electrode, P. A. Reshani H. Perera

ETD Archive

Nitric oxide (NO) is a freely diffusible, gaseous free radical, associated with many physiological and pathological processes that include neuronal signaling, immune response, and inflammatory response. NO is produced from L-arginine in an NADPH-dependent reaction catalyzed by a family of nitric oxide synthase (NOS) enzymes. A deficiency in NO plays a role in hypertension, hyperglycaemia, and arteriosclerosis, among other pathological states. Conversely, increased NO levels contribute to arthritis, septic shock, and hypotention. Therefore, measuring and quantifying NO production in biological systems and matrices may be vital in elucidating physiological and pathological processes. The goal of this work is to develop …


One Parameter Control Of The Size Of Iron Oxide Nanoparticles Synthesized In Reverse Micelles, M. D. Shultz, W. Braxton, C. Taylor, E. E. Carpenter Jan 2009

One Parameter Control Of The Size Of Iron Oxide Nanoparticles Synthesized In Reverse Micelles, M. D. Shultz, W. Braxton, C. Taylor, E. E. Carpenter

Chemistry Publications

Iron oxide nanoparticles were synthesized via reverse micelle methods. The initial iron concentration was varied, while maintaining all other parameters constant, in order to investigate the effect of the iron concentration on the resultant iron oxide nanoparticle size. Increasing the iron concentration from 0.125M to 0.5M yielded an increase in average nanoparticle diameter from 4.71 to 7.95 nm, as measured by transmission electron microscopy. Three other concentrations between 0.125M and 0.5M showed corresponding size variations, all with statistical significance. Magnetic characterization by vibrating sample magnetometry and powder x-ray diffraction was performed to verify proper phase and material. Further insight into …


Synthesis Of 5-Methoxy-7-Methylbicyclo[3.2.0]Hept-2-En-6-Ol, Harlan Reid Jan 2009

Synthesis Of 5-Methoxy-7-Methylbicyclo[3.2.0]Hept-2-En-6-Ol, Harlan Reid

Theses, Dissertations and Capstones

In order to generate a chiral metallocene ligand similar to Kaminsky-Sinn catalysts, a multistep synthesis for the production of 6,7-dimethylbicyclo[3.2.0]hepta-1,3-dienyl anion was proposed. Experiments directed at the initial phase of the proposal are included, ending with the characterization of new alcohols in compounds 9 through 12. Two steps from the synthesis were successfully combined, leading to improved recovery of the alcohols.


High Resolution Single Molecule Optical Localization Of Multiple Fluorophores On Dna Origami Constructs Fluorophores On Dna Origami Constructs, Anuradha Rajulapati Jan 2009

High Resolution Single Molecule Optical Localization Of Multiple Fluorophores On Dna Origami Constructs Fluorophores On Dna Origami Constructs, Anuradha Rajulapati

Theses, Dissertations and Capstones

An ongoing challenge in the development of nanoelectronics and nanophotonics is the nondestructive, high-resolution localization in space of single molecules and multi-molecular assemblies. The apparent barrier to the use of optical microscopy at the sub-100 nm scale is the well known Abbe Limit, the diffraction limit to resolution. This laboratory has adapted a technique called Single-molecule high resolution imaging with photobleaching (SHRIMP). We have developed methods for utilizing SHRIMP for the determination of the separation of two fluorophores in single DNA origami constructs.

DNA Origami is extremely useful because it can address nanocomponents down to 2nm separation. It should be …