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

Physical Sciences and Mathematics Commons™

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

Chemistry

Selected Works

Selected Works

2005

Articles 1 - 21 of 21

Full-Text Articles in Physical Sciences and Mathematics

Optimization Of Electrode Alignment For Electrochemical Detection In Capillary Electrophoresis Using A Scanning Electrochemical Microscope, David Roach, Stephanie Hooper, Mark Anderson Nov 2005

Optimization Of Electrode Alignment For Electrochemical Detection In Capillary Electrophoresis Using A Scanning Electrochemical Microscope, David Roach, Stephanie Hooper, Mark Anderson

Mark R. Anderson

Electrochemical detection in capillary electrophoresis requires decoupling the voltage applied to the working electrode from the separation voltage applied across the capillary. End-capillary electrochemical detection achieves this by placing the electrode just outside the ground end of the separation capillary. Obtaining adequate signal-to-noise in this arrangement requires using small inner diameter capillaries. Decreasing the inner diameter of the separation capillary, however, increases the difficulty of aligning the microelectrode with the open end of the capillary. Using scanning electrochemical microscopy (SECM), the position of the capillary opening is determined while electroactive material is continuously emerging from the end of the capillary. …

Go to article

1,4-Dimethyl-1,4-Diazoniabicyclo[2.2.2]Octane Diiodide Acetonitrile Solvate, Daron E. Janzen, Paul C. Ewbank, Kent R. Mann Nov 2005

1,4-Dimethyl-1,4-Diazoniabicyclo[2.2.2]Octane Diiodide Acetonitrile Solvate, Daron E. Janzen, Paul C. Ewbank, Kent R. Mann

Daron E Janzen, Ph.D.

No abstract provided.

Go to article

Application Of Correlation-Gas Chromatography To Evaluate The Vaporization Enthalpy Of A Component In An Equilibrium Mixture, Manuel Temprado, James S. Chickos Aug 2005

Application Of Correlation-Gas Chromatography To Evaluate The Vaporization Enthalpy Of A Component In An Equilibrium Mixture, Manuel Temprado, James S. Chickos

James Chickos

No abstract provided.

Go to article

Unraveling The Mechanism Of A Potent Transcriptional Activator, Brian Brennan, Zhen Lu, Steven Rowe, Sarah Davis, Renee Metzler, Johnathan Nau, Chinmay Majmudar, Anna Mapp, Aseem Ansari Aug 2005

Unraveling The Mechanism Of A Potent Transcriptional Activator, Brian Brennan, Zhen Lu, Steven Rowe, Sarah Davis, Renee Metzler, Johnathan Nau, Chinmay Majmudar, Anna Mapp, Aseem Ansari

Brian B. Brennan

Despite their enormous potential as novel research tools and therapeutic agents, artificial transcription factors (ATFs) that up-regulate transcription robustly in vivo remain elusive. In investigating an ATF that does function exceptionally well in vivo, we uncovered an unexpected relationship between transcription function and a binding interaction between the activation domain and an adjacent region of the DNA binding domain. Disruption of this interaction leads to complete loss of function in vivo, even though the activation domain is still able to bind to its target in the transcriptional machinery. We propose that this interaction parallels those between natural activation domains and …

Go to article

Polymers With Pendant Coumarins: Synthesis And Characterization Of Polystyrenes And Polymethacrylates With Pendant Coumarin Moieties, T. Christopher Corkery Jun 2005

Polymers With Pendant Coumarins: Synthesis And Characterization Of Polystyrenes And Polymethacrylates With Pendant Coumarin Moieties, T. Christopher Corkery

Chris Corkery

No abstract provided.

Go to article

The Synthesis Of Chiral Lactones From Racemic -Hydroxyamides Using The Amidase From Brevibacterium Sp. Strain R312, Thomas Goyne, Jennifer Yamaoka, Matthew Pridgeon, Kyle Miner, Stephen Taylor, Min-Ken Liao Mar 2005

The Synthesis Of Chiral Lactones From Racemic -Hydroxyamides Using The Amidase From Brevibacterium Sp. Strain R312, Thomas Goyne, Jennifer Yamaoka, Matthew Pridgeon, Kyle Miner, Stephen Taylor, Min-Ken Liao

Thomas Goyne

No abstract provided.

Go to article

Using A Microplate Reader To Add A ‘Taste Of Research’ To An Undergraduate Biochemistry Teaching Laboratory, Thomas Goyne, Kasey Hammond, Kevin Mccusker, Jacob Riehm Mar 2005

Using A Microplate Reader To Add A ‘Taste Of Research’ To An Undergraduate Biochemistry Teaching Laboratory, Thomas Goyne, Kasey Hammond, Kevin Mccusker, Jacob Riehm

Thomas Goyne

No abstract provided.

Go to article

Modified Electrodes For Mediated Electron Transport: Detection Of Glucose And Glutamate, Alice Harper, Mark Anderson Feb 2005

Modified Electrodes For Mediated Electron Transport: Detection Of Glucose And Glutamate, Alice Harper, Mark Anderson

Mark R. Anderson

No abstract is currently available.

Go to article

Electrode Placement Optimization For Capillary Electrophoresis Using A Scanning Electrochemical Microscope, David Roach, Mark Anderson Feb 2005

Electrode Placement Optimization For Capillary Electrophoresis Using A Scanning Electrochemical Microscope, David Roach, Mark Anderson

Mark R. Anderson

No abstract is currently available.

Go to article

Studies Toward Understanding The Role Of Molecular Structure And Bulk Interfacial Properties, Mark Anderson Feb 2005

Studies Toward Understanding The Role Of Molecular Structure And Bulk Interfacial Properties, Mark Anderson

Mark R. Anderson

No abstract is available at this time.

Go to article

Studies Of The Relationship Between The Structure And Properties Of Interfacial Thin Films, Mark Anderson Jan 2005

Studies Of The Relationship Between The Structure And Properties Of Interfacial Thin Films, Mark Anderson

Mark R. Anderson

No abstract is available at this time.

Go to article

Amyloid-Β Protofibrils Differ From Amyloid-Β Aggregates Induced In Dilute Hexafluoroisopropanol In Stability And Morphology, Michael Nichols, Melissa A. Moss, Dana K. Reed, Stephanie Cratic-Mcdaniel, Jan H. Hoh, Terrone L. Rosenberry Jan 2005

Amyloid-Β Protofibrils Differ From Amyloid-Β Aggregates Induced In Dilute Hexafluoroisopropanol In Stability And Morphology, Michael Nichols, Melissa A. Moss, Dana K. Reed, Stephanie Cratic-Mcdaniel, Jan H. Hoh, Terrone L. Rosenberry

Michael Nichols

The brains of Alzheimer’s disease (AD) patients contain large numbers of amyloid plaques that are rich in fibrils composed of 40- and 42-residue amyloid-#1; (A#1;) peptides. Several lines of evidence indicate that fibrillar A#1; and especially soluble A#1; aggregates are important in the etiology of AD. Recent reports also stress that amyloid aggregates are polymorphic and that a single polypeptide can fold into multiple amyloid conformations. Here we demonstrate that A#1;-(1–40) can form soluble aggregates with predominant #1;-structures that differ in stability and morphology. One class of aggregates involved soluble A#1; protofibrils, prepared by vigorous overnight agitation of monomeric A#1;-(1–40) …

Go to article

Measurement Of The Vaporization Enthalpy Of Complex Mixtures By Correlation-Gas Chromatography. The Vaporization Enthalpy Of Rp-1, Jp-7, And Jp-8 Rocket And Jet Fuels At T = 298.15 K, James S. Chickos, Hui Zhao Jan 2005

Measurement Of The Vaporization Enthalpy Of Complex Mixtures By Correlation-Gas Chromatography. The Vaporization Enthalpy Of Rp-1, Jp-7, And Jp-8 Rocket And Jet Fuels At T = 298.15 K, James S. Chickos, Hui Zhao

James Chickos

No abstract provided.

Go to article

Cubane, Cuneane, And Their Carboxylates: A Calorimetric, Crystallographic, Calculational, And Conceptual Coinvestigation., Maria Victoria Roux, Juan Z. Davalos, Pilar Jimenez, Rafael Notario, Obis Castano, James S. Chickos, William Hanshaw, Hui Zhao, Nigam Rath, Joel F. Liebman, Behzad S. Farivar, A. Bashir-Hashemi Jan 2005

Cubane, Cuneane, And Their Carboxylates: A Calorimetric, Crystallographic, Calculational, And Conceptual Coinvestigation., Maria Victoria Roux, Juan Z. Davalos, Pilar Jimenez, Rafael Notario, Obis Castano, James S. Chickos, William Hanshaw, Hui Zhao, Nigam Rath, Joel F. Liebman, Behzad S. Farivar, A. Bashir-Hashemi

James Chickos

No abstract provided.

Go to article

The Thermochemistry Of 2,4-Pentanedione Revisited: Observance Of A Nonzero Enthalpy Of Mixing Between Tautomers And Its Effects On Enthalpies Of Formation, Manuel Temprado, Maria Victoria Roux, Patamaporn Umnahanant, Hui Zhao, James S. Chickos Jan 2005

The Thermochemistry Of 2,4-Pentanedione Revisited: Observance Of A Nonzero Enthalpy Of Mixing Between Tautomers And Its Effects On Enthalpies Of Formation, Manuel Temprado, Maria Victoria Roux, Patamaporn Umnahanant, Hui Zhao, James S. Chickos

James Chickos

No abstract provided.

Go to article

Stereochemical Promiscuity In Artificial Transcriptional Activators, Brian Brennan, Sara Buhrlage, Aaron Minter, Anna Mapp Dec 2004

Stereochemical Promiscuity In Artificial Transcriptional Activators, Brian Brennan, Sara Buhrlage, Aaron Minter, Anna Mapp

Brian B. Brennan

Small molecule replacements of transcriptional activation domains are highly desirable targets due to their utility as mechanistic tools and their long-term therapeutic potential for a variety of human diseases. Here, we examine the ability of amphipathic isoxazolidines differing only in the placement of constituent side chains to function as transcriptional activation domains. The results reveal that precise positioning of functional groups within a conformationally constrained small molecule scaffold is not required for transcription function; rather, the balance of polarity and hydrophobicity within the scaffold is the more important determinant of transcription function. This suggests that a number of different organic …

Go to article

A Solvent-Free Baeyer–Villiger Lactonization For The Undergraduate Organic Laboratory: Synthesis Of Γ-T-Butyl-Ε-Caprolactone, John Esteb, James Hohman, Diana Schlamadinger, Anne Wilson Dec 2004

A Solvent-Free Baeyer–Villiger Lactonization For The Undergraduate Organic Laboratory: Synthesis Of Γ-T-Butyl-Ε-Caprolactone, John Esteb, James Hohman, Diana Schlamadinger, Anne Wilson

John Esteb

We present an experiment involving the Baeyer–Villiger oxidation reactionfor a first-year organic chemistry class. The Baeyer–Villiger reactionprovides an efficient method to convert ketones to esters or lactones. Most organictextbooks cover the Baeyer–Villiger reaction but owing to a lack of suitableexperiments, students seldom get to explore the reaction in the undergraduateteaching laboratory. In this experiment, m-chloroperoxybenzoic acid(m-CPBA) and4-tert-butylcyclohexanone are mixed together for 30 minutes under solvent-freeconditions to produce γ-t-butyl-ε-caprolactone in 95%yield. The solvent-free nature of this procedure greatly limits the quantityof waste generated by students and keeps costs low by removing the need for solvent.

Note:Link is to the article …

Go to article

Environment Friendly Organic Synthesis Using Bismuth Compounds. An Efficient Method For Carbonyl-Ene Reactions Catalyzed By Bismuth Triflate, Ram S. Mohan, Erin D. Anderson, Justin J. Ernat, Mai P. Nguyen, Ann C. Palma Dec 2004

Environment Friendly Organic Synthesis Using Bismuth Compounds. An Efficient Method For Carbonyl-Ene Reactions Catalyzed By Bismuth Triflate, Ram S. Mohan, Erin D. Anderson, Justin J. Ernat, Mai P. Nguyen, Ann C. Palma

Ram S. Mohan

Bismuth triflate (0.1 mol %) is a highly efficient catalyst for the cyclization of citronellal 1, a reaction that yields a ratio of 80:20 of isopulegol 2 and neoisopulegol 3. This methodology has also been extended to the synthesis of substituted piperidines. The bismuth triflate catalyzed ene reaction of aldehyde 4 gives a 70:30 mixture of piperidines 5 and 6. The advantages of these methods include the use of a highly efficient catalyst that is relatively nontoxic, cheap and easy to handle.

Go to article

A Study Of Epoxyolefin Cyclizations Catalyzed By Bismuth Trifluoromethanesulfonate And Other Metal Triflates, Ram S. Mohan, Joshua R. Lacey, Peter W. Anzalone, Christopher M. Duncan, Matthew J. Hackert Dec 2004

A Study Of Epoxyolefin Cyclizations Catalyzed By Bismuth Trifluoromethanesulfonate And Other Metal Triflates, Ram S. Mohan, Joshua R. Lacey, Peter W. Anzalone, Christopher M. Duncan, Matthew J. Hackert

Ram S. Mohan

Epoxyolefin cyclizations have attracted considerable interest due to their importance in biosynthetic pathways. Bismuth trifluoromethanesulfonate as well as several other metal triflates are shown to be highly effective (0.1 mol %) catalysts for the cyclization of geraniolene oxide. The product composition is found to be more dependent on solvent and substrate concentration than on the nature of the metal triflate. Cyclization products are favored in CH2Cl2 and under high dilution conditions. Ether solvents favored acyclic products.

Go to article

The Discovery-Oriented Approach To Organic Chemistry. 6. Selective Reduction In Organic Chemistry: Reduction Of Aldehydes In The Presence Of Esters Using Sodium Borohydride, Ram S. Mohan, Ashvin R. Baru Dec 2004

The Discovery-Oriented Approach To Organic Chemistry. 6. Selective Reduction In Organic Chemistry: Reduction Of Aldehydes In The Presence Of Esters Using Sodium Borohydride, Ram S. Mohan, Ashvin R. Baru

Ram S. Mohan

Chemoselective reductions are valuable in organic synthesis and are routinely discussed in a sophomore organic chemistry course. Yet, there are few examples of laboratory experiments that illustrate such chemoselectivity. A reaction that is routinely discussed in sophomore organic chemistry is the selective reduction of aldehydes and ketones using sodium borohydride. Esters are typically not affected by NaBH4. However, none of the lab experiments reported to date illustrate this chemoselectivity (1). We have developed a discovery-oriented lab experiment that illustrates the chemoselective nature of reductions using sodium borohydride. The experiments involve the reduction of vanillin acetate (Scheme I) and methyl …

Go to article

Interactions Between Xenon And Phospholipid Bicelles Studied By 2h/129xe/131xe Nmr And Optical Pumping Of Nuclear Spins, Xiaoxia Li, Caitlin Newberry, Indrajit Saha, Panayiotis Nikolaou, Nicholas Whiting, Boyd M. Goodson Dec 2004

Interactions Between Xenon And Phospholipid Bicelles Studied By 2h/129xe/131xe Nmr And Optical Pumping Of Nuclear Spins, Xiaoxia Li, Caitlin Newberry, Indrajit Saha, Panayiotis Nikolaou, Nicholas Whiting, Boyd M. Goodson

Nicholas Whiting

The interactions between xenon and DMPC/DHPC bicelles (q = 3.5%,7.5% w/v) were studied via 2H, 129Xe, 131Xe, and optically enhanced 129Xe NMR. The chemical shifts, linewidths, and quadrupolar couplings of the xenon/bicelle NMR signals were correlated with different regions of the bicellar phase diagram. The addition of xenon (<70 mM) was observed to reduce the temperature-onset of bicelle alignment by several degrees, in quantitative agreement with effects previously observed with chloroform; however, the stable liquid-crystalline range was not significantly reduced. Preliminary laser-polarized xenon/bicelle studies yielded 129Xe T1 values of ~120 s, long enough to permit a variety of planned experiments.

Go to article