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Full-Text Articles in Chemistry

Steel Hull Corrosion Of Uss Arizona With Applications To Submerged Resources, D. L. Johnson, D. J. Medlin, M. A. Russell, D. L. Conlin, L. E. Murphy, J. D. Carr Jan 2009

Steel Hull Corrosion Of Uss Arizona With Applications To Submerged Resources, D. L. Johnson, D. J. Medlin, M. A. Russell, D. L. Conlin, L. E. Murphy, J. D. Carr

Department of Chemistry: Faculty Publications

The USS Arizona Preservation project is a multi-year, interdisciplinary and cumulative effort with each discipline contributing to basic research required to make informed management decisions for long-term preservation. Three significant issues include: (1) USS Arizona is a grave site for 900 or more Navy and Marine personal lost with the USS Arizona when Japanese forces attacked Pearl Harbor on Dec 7, 1941. (2) Minimizing environmental hazard from a potential fuel oil release of an estimated 500,000 gallons remaining in fuel bunkers or compartment overheads. A cross section view of the ship and bunkers before and after the attack is shown …


Quantum Mechanical/Molecular Mechanical/Continuum Style Solvation Model: Linear Response Theory, Variational Treatment, And Nuclear Gradients, Hui Li Jan 2009

Quantum Mechanical/Molecular Mechanical/Continuum Style Solvation Model: Linear Response Theory, Variational Treatment, And Nuclear Gradients, Hui Li

Department of Chemistry: Faculty Publications

Linear response and variational treatment are formulated for Hartree–Fock (HF) and Kohn–Sham density functional theory (DFT) methods and combined discrete-continuum solvation models that incorporate self-consistently induced dipoles and charges. Due to the variational treatment, analytic nuclear gradients can be evaluated efficiently for these discrete and continuum solvation models. The forces and torques on the induced point dipoles and point charges can be evaluated using simple electrostatic formulas as for permanent point dipoles and point charges, in accordance with the electrostatic nature of these methods. Implementation and tests using the effective fragment potential (EFP, a polarizable force field) method and the …


Energy Decomposition Analysis Of Covalent Bonds And Intermolecular Interactions, Peifeng Su, Hui Li Jan 2009

Energy Decomposition Analysis Of Covalent Bonds And Intermolecular Interactions, Peifeng Su, Hui Li

Department of Chemistry: Faculty Publications

An energy decomposition analysis method is implemented for the analysis of both covalent bonds and intermolecular interactions on the basis of single-determinant Hartree–Fock (HF) (restricted closed shell HF, restricted open shell HF, and unrestricted open shell HF) wavefunctions and their density functional theory analogs. For HF methods, the total interaction energy from a supermolecule calculation is decomposed into electrostatic, exchange, repulsion, and polarization terms. Dispersion energy is obtained from second-order Møller–Plesset perturbation theory and coupled-cluster methods such as CCSD and CCSD(T). Similar to the HF methods, Kohn–Sham density functional interaction energy is decomposed into electrostatic, exchange, repulsion, polarization, and dispersion …


Immobilization Method For Producing Active Α1-Acid Glycoprotein, David S. Hage, Hai Xuan Jan 2009

Immobilization Method For Producing Active Α1-Acid Glycoprotein, David S. Hage, Hai Xuan

Department of Chemistry: Faculty Publications

A method and kit for immobilization of a glycoprotein. The method may include activating an affinity Support. The affinity Support may be activated by reacting the affinity Support with a compound that is reactive with one or more functional groups included within the glycoprotein. The method may also include oxidizing the glycoprotein in which oxidation conditions are selected to yield an oxidized glycoprotein that is biologically active and contains a Sufficient number of reactive aldehyde groups for coupling to a Support. For example, the oxidized glycoprotein may include five reactive aldehyde groups. In addition, the method may include reacting the …


Heterogeneous Conductorlike Solvation Model, Hui Li, Dejun Si Jan 2009

Heterogeneous Conductorlike Solvation Model, Hui Li, Dejun Si

Department of Chemistry: Faculty Publications

A heterogeneous conductorlike solvation model (conductorlike screening model/conductorlike polarizable continuum model) that uses different local effective dielectrics for different portions of the solute cavity surface is implemented for quantum chemical Hartree–Fock and Kohn–Sham methods. A variational treatment is used to form the heterogeneous solvation operator, so a simple analytic expression of the energy gradients, which are vital for geometry optimization and molecular dynamics simulation, is derived and implemented. Using the new Fixed Points with Variable Areas surface tessellation scheme, continuous and smooth potential energy surfaces as well as analytic gradients are obtained for this heterogeneous model.


Techniques For Consecutive Tem And Atom Probe Tomography Analysis Of Nanowires, D. R. Diercks, B. P. Gorman, Chin Li Cheung, G. Wang Jan 2009

Techniques For Consecutive Tem And Atom Probe Tomography Analysis Of Nanowires, D. R. Diercks, B. P. Gorman, Chin Li Cheung, G. Wang

Department of Chemistry: Faculty Publications

Nanowires show great promise for development in many technological applications including electronics, photonics, and displays . Due to the fine scale of nanowires, transmission electron microscopy (TEM) and atom probe tomography (APT) are among a limited number of techniques that can measure the crystallographic and chemical nature of these structures which ultimately define their performance.


Continuous And Smooth Potential Energy Surface For Conductorlike Screening Solvation Model Using Fixed Points With Variable Areas, Peifeng Su, Hui Li Jan 2009

Continuous And Smooth Potential Energy Surface For Conductorlike Screening Solvation Model Using Fixed Points With Variable Areas, Peifeng Su, Hui Li

Department of Chemistry: Faculty Publications

Rigorously continuous and smooth potential energy surfaces, as well as exact analytic gradients, are obtained for a conductorlike screening solvation model (CPCM, a variant of the general COSMO) with Hartree–Fock (RHF, ROHF, UHF, and MCSCF) and density functional theory (R-DFT, RO-DFT, and U-DFT) methods using a new tessellation scheme, fixed points with variable areas (FIXPVA). In FIXPVA, spheres centered at atoms are used to define the molecular cavity and surface. The surface of each sphere is divided into 60, 240, or 960 tesserae, which have positions fixed relative to the sphere center and areas scaled by switching functions of their …


Smooth Potential Energy Surface For Cavitation, Dispersion, And Repulsion Free Energies In Polarizable Continuum Model, Yali Wang, Hui Li Jan 2009

Smooth Potential Energy Surface For Cavitation, Dispersion, And Repulsion Free Energies In Polarizable Continuum Model, Yali Wang, Hui Li

Department of Chemistry: Faculty Publications

The fixed points with variable areas [FIXPVA (Ref. 1)] tessellation scheme is used to obtain smooth potential energy surfaces for the cavitation Gcav, dispersion Gdis, and repulsion Grep free energies in the polarizable continuum model (PCM). It is shown that FIXPVA can reproduce the standard GEPOL (Ref. 4) results to within 1 kcal/mol.


A New Peroxide Fragmentation: Efficient Chemical Generation Of 1O2 In Organic Media, Patrick Dussault, Prasanta Ghorai Jan 2009

A New Peroxide Fragmentation: Efficient Chemical Generation Of 1O2 In Organic Media, Patrick Dussault, Prasanta Ghorai

Department of Chemistry: Faculty Publications

Monoactivated derivatives of 1,1-dihydroperoxides undergo an unprecedented base-promoted fragmentation to efficiently generate singlet oxygen (1O2) in anhydrous organic solvents.


A Multi-Step Nmr Screen For The Identification And Evaluation Of Chemical Leads For Drug Discovery, Kelly A. Mercier, Matthew D. Shortridge, Robert Powers Jan 2009

A Multi-Step Nmr Screen For The Identification And Evaluation Of Chemical Leads For Drug Discovery, Kelly A. Mercier, Matthew D. Shortridge, Robert Powers

Department of Chemistry: Faculty Publications

A multi-step NMR based screening assay is described for identifying and evaluating chemical leads for their ability to bind a target protein. The multi-step NMR assay provides structure-related information while being an integral part of a structure based drug discovery and design program. The fundamental principle of the multi-step NMR assay is to combine distinct 1D and 2D NMR techniques, in such a manner, that the inherent strengths and weakness associated with each technique is complementary to each other in the screen. By taking advantage of the combined strengths of 1D and 2D NMR experiments, it is possible to minimize …


Anhydrous Fluoride Salts And Reagents And Methods For Their Production, Stephen G. Dimagno, Haoran Sun Jan 2009

Anhydrous Fluoride Salts And Reagents And Methods For Their Production, Stephen G. Dimagno, Haoran Sun

Department of Chemistry: Faculty Publications

Anhydrous organic fluoride salts and reagents prepared by a method comprising the nucleophilic Substitution of a fluorinated aromatic or fluorinated unsaturated organic compound with a salt having the formula: [QnM]x+Ax- in an inert polar, aprotic solvent; wherein M is an atom capable of supporting a formal positive charge, the n groups Q are independently varied organic moieties, n is an integer such that the [QnM] carries at least one formal positive charge, x is an integer defining the number of formal positive charge(s), +, carried by the [QnM], A- …


Local Structures Surrounding Zr In Nanostructurally Stabilized Cubic Zirconia: Structural Origin Of Phase Stability, Y. L. Soo, P. J. Chen, S. H. Huang, T. J. Shiu, T. Y. Tsai, Y. H. Chow, Y. C. Lin, S. C. Weng, S. L. Chang, G. Wang, Chin Li Cheung, Renat F. Sabirianov, Wai-Ning Mei, F. Namavar, H. Haider, K. L. Garvin, J. F. Lee, H. Y. Lee, P. P. Chu Jan 2008

Local Structures Surrounding Zr In Nanostructurally Stabilized Cubic Zirconia: Structural Origin Of Phase Stability, Y. L. Soo, P. J. Chen, S. H. Huang, T. J. Shiu, T. Y. Tsai, Y. H. Chow, Y. C. Lin, S. C. Weng, S. L. Chang, G. Wang, Chin Li Cheung, Renat F. Sabirianov, Wai-Ning Mei, F. Namavar, H. Haider, K. L. Garvin, J. F. Lee, H. Y. Lee, P. P. Chu

Department of Chemistry: Faculty Publications

Local environment surrounding Zr atoms in the thin films of nanocrystalline zirconia (ZrO2) has been investigated by using the extended x-ray absorption fine structure (EXAFS) technique. These films prepared by the ion beam assisted deposition exhibit long-range structural order of cubic phase and high hardness at room temperature without chemical stabilizers. The local structure around Zr probed by EXAFS indicates a cubic Zr sublattice with O atoms located on the nearest tetragonal sites with respect to the Zr central atoms, as well as highly disordered locations. Similar Zr local structure was also found in a ZrO2 nanocrystal …


Classification Of Chemical Reactions: Stages Of Expertise, Marilyne Stains, Vicente Talanquer Jan 2008

Classification Of Chemical Reactions: Stages Of Expertise, Marilyne Stains, Vicente Talanquer

Department of Chemistry: Faculty Publications

In this study we explore the strategies that undergraduate and graduate chemistry students use when engaged in classification tasks involving symbolic and microscopic (particulate) representations of different chemical reactions. We were specifically interested in characterizing the basic features to which students pay attention when classifying chemical reactions at the symbolic and microscopic levels. We identified the categories that students create when classifying chemical reactions, and compared the performance in simple classification tasks of students with different levels of preparation in the discipline. Our results suggest that advanced levels of expertise in chemical classification do not necessarily evolve in a linear …


Tris(Dialkylamino)Aluminums: Syntheses, Characterization, Volatility Comparison, And Atomic Layer Deposition Of Alumina Thin Films, Casey R. Wade, Carter Silvernail, Chiranjib Banerjee, Axel Soulet, James Mcandrew, John A. Belot Jr. Dec 2007

Tris(Dialkylamino)Aluminums: Syntheses, Characterization, Volatility Comparison, And Atomic Layer Deposition Of Alumina Thin Films, Casey R. Wade, Carter Silvernail, Chiranjib Banerjee, Axel Soulet, James Mcandrew, John A. Belot Jr.

Department of Chemistry: Faculty Publications

The syntheses and characterization of both tris(diethylamino)aluminum and tris(diisopropylamino)aluminum are presented in this letter. Characterization includes vapor pressure measurements and comparison of the two non-pyrophoric precursors showing them to be viable alternatives to trimethylaluminum. Ultimately, tris(diisopropyl)aluminum was successful in the atomic layer deposition of alumina thin films.


A Strategy To Protect And Sensitize Near-Infrared Luminescent Nd3+ And Yb3+: Organic Tropolonate Ligands For The Sensitization Of Ln3+-Doped Nayf4 Nanocrystals, Jian Zhang, Chad M. Shade, Demetra A. Chengelis, Stéphane Petoud Nov 2007

A Strategy To Protect And Sensitize Near-Infrared Luminescent Nd3+ And Yb3+: Organic Tropolonate Ligands For The Sensitization Of Ln3+-Doped Nayf4 Nanocrystals, Jian Zhang, Chad M. Shade, Demetra A. Chengelis, Stéphane Petoud

Department of Chemistry: Faculty Publications

A strategy to sensitize and protect near-infrared (NIR) emitting Nd3+ and Yb3+ is presented. Combining protection provided by the inorganic matrix of NaYF4 nanocrystals and sensitization from tropolonate ligands capped on their surface, the lanthanide cation centered luminescence was observed through the ligand excitation. The extended lanthanide luminescence lifetimes indicate the success of this strategy.


Synthesis And Structural Characterization Of Two Five Coordinate Aluminum Alkyl And Bis(Trimethylsilyl)Amino Complexes Bearing Acyclic Tetradentate Schiff Bases, C. R. Wade, B. J. Lamprecht, V. W. Day, John A. Belot Aug 2007

Synthesis And Structural Characterization Of Two Five Coordinate Aluminum Alkyl And Bis(Trimethylsilyl)Amino Complexes Bearing Acyclic Tetradentate Schiff Bases, C. R. Wade, B. J. Lamprecht, V. W. Day, John A. Belot

Department of Chemistry: Faculty Publications

Two acyclic Schiff-base ligands, bis-5,5′-(1,3-propanediyldiimino)-2,2-dimethyl-4-hexene-3-one and bis-5,5′-(1,3-ethanediyldiimino)- 2,2-dimethyl-4-hexene-3-one, were used to complex homoleptic triethylaluminum and tris[bis(trimethylsilyl)amino]alu minum, respectively. The acid–base reactions proceeded in excellent yields with elimination of ethane or bis(trimethylsilyl)amine during in situ deprotonation of the protio Schiff-base. The colorless aluminum complexes crystallized from n-pentane and were characterized by standard methods including single crystal X-ray diffraction. Polymerization of racemic lactide, with addition of alcohol, yielded PLA with narrow polydispersities but low molecular weights.


Classification Of Chemical Substances Using Particulate Representations Of Matter: An Analysis Of Student Thinking, Marilyne Stains, Vicente Talanquer Apr 2007

Classification Of Chemical Substances Using Particulate Representations Of Matter: An Analysis Of Student Thinking, Marilyne Stains, Vicente Talanquer

Department of Chemistry: Faculty Publications

We applied a mixed-method research design to investigate the patterns of reasoning used by novice undergraduate chemistry students to classify chemical substances as elements, compounds, or mixtures based on their particulate representations. We were interested in the identification of the representational features that students use to build a classification system, and in the characterization of the thinking processes that they follow to group substances in different classes. Students in our study used structural and chemical composition features to classify chemical substances into elements, compounds, and mixtures. Many of the students’ classification errors resulted from strong mental associations between concepts (e.g., …


Structure And Biosynthesis Of Heat-Stable Antifungal Factor (Hsaf), A Broad-Spectrum Antimycotic With A Novel Mode Of Action, Fengan Yu, Kathia Zaleta-River, Xiangcheng Zhu, Justin Huffman, Jeffrey C. Millet, Steven D. Harris, Gary Y. Yuen, Xing-Cong Li, Liangcheng Du Jan 2007

Structure And Biosynthesis Of Heat-Stable Antifungal Factor (Hsaf), A Broad-Spectrum Antimycotic With A Novel Mode Of Action, Fengan Yu, Kathia Zaleta-River, Xiangcheng Zhu, Justin Huffman, Jeffrey C. Millet, Steven D. Harris, Gary Y. Yuen, Xing-Cong Li, Liangcheng Du

Department of Chemistry: Faculty Publications

A screen for antifungal compounds from Lysobacter enzymogenes strain C3, a bacterial biological control agent of fungal diseases, has previously led to the isolation of heat-stable antifungal factor (HSAF). HSAF exhibits inhibitory activities against a wide range of fungal species and shows a novel mode of antifungal action by disrupting the biosynthesis of a distinct group of sphingolipids. We have now determined the chemical structure of HSAF, which is identical to that of dihydromaltophilin, an antifungal metabolite with a unique macrocyclic lactam system containing a tetramic acid moiety and a 5,5,6-tricyclic skeleton. We have also identified the genetic locus responsible …


Corrosion Studies On The Uss Arizona With Application To A Japanese Midget Submarine, Brent M. Wilson, Donald L. Johnson, Hans Vantilburg, Matthew A. Russell, Larry E. Murphy, James D. Carr, Robert J. De Angelis, David L. Conlin Jan 2007

Corrosion Studies On The Uss Arizona With Application To A Japanese Midget Submarine, Brent M. Wilson, Donald L. Johnson, Hans Vantilburg, Matthew A. Russell, Larry E. Murphy, James D. Carr, Robert J. De Angelis, David L. Conlin

Department of Chemistry: Faculty Publications

The assessment of corrosion on the USS Arizona included the pioneering development of a minimum-impact cost-effective technique to determine the corrosion rate of steel-hulled shipwrecks in seawater. The technique, with potential application worldwide, is illustrated in this paper with the application to a World War II Japanese midget submarine submerged in deep waters off the Oahu, Hawaii, coast.


Electrolytic Deposition Of Coatings For Prosthetic Metals And Alloys, Jody G. Redepenning Mar 2006

Electrolytic Deposition Of Coatings For Prosthetic Metals And Alloys, Jody G. Redepenning

Department of Chemistry: Faculty Publications

An article coated with an electrolytically deposited biocompatible composite layer useful as an internal prosthetic device is disclosed. The bio-compatible composite coating that is electrolytically deposited onto the article comprises hydroxyapatite and chitosan. The introduction of chitosan into the crystal matrix of brushite/hydroxyapatite significantly improves the adhesive and chemical and mechanical stability properties of the coating.
United States Patent Number 7,014,749 B2


Negative Impact Of Noise On The Principal Component Analysis Of Nmr Data, Steven M. Halouska, Robert Powers Jan 2006

Negative Impact Of Noise On The Principal Component Analysis Of Nmr Data, Steven M. Halouska, Robert Powers

Department of Chemistry: Faculty Publications

Principal component analysis (PCA) is routinely applied to the study of NMR based metabolomic data. PCA is used to simplify the examination of complex metabolite mixtures obtained from biological samples that may be composed of hundreds or thousands of chemical components. PCA is primarily used to identify relative changes in the concentration of metabolites to identify trends or characteristics within the NMR data that permits discrimination between various samples that differ in their source or treatment. A common concern with PCA of NMR data is the potential over emphasis of small changes in high concentration metabolites that would over-shadow signifi …


Stability Of Warfarin Solutions For Drug–Protein Binding Measurements: Spectroscopic And Chromatographic Studies, Annette C. Moser, Charles A. Kingsbury, David S. Hage Jan 2006

Stability Of Warfarin Solutions For Drug–Protein Binding Measurements: Spectroscopic And Chromatographic Studies, Annette C. Moser, Charles A. Kingsbury, David S. Hage

Department of Chemistry: Faculty Publications

Warfarin is commonly used in drug–protein binding studies as a displacement marker for Sudlow site I on the protein human serum albumin (HSA). This study examined the stability of aqueous warfarin solutions prepared for such experiments. This was investigated using NMR spectroscopy and affinity chromatography. It was found by 1H NMR that warfarin underwent a slow first-order conversion in aqueous solution. The rate of this reaction increased with temperature, giving rate constants at pH 7.4 of 0.0086 h−1 at 25 °C and 0.041 h−1 at 37 °C. It was concluded from further 1H and 13C NMR studies, along …


A Minimum-Impact Method For Measuring Corrosion Rate Of Steel-Hulled Shipwrecks In Seawater, Matthew A. Russell, David L. Conlin, Larry E. Murphy, Donald L. Johnson, Brent M. Wilson, James D. Carr Jan 2006

A Minimum-Impact Method For Measuring Corrosion Rate Of Steel-Hulled Shipwrecks In Seawater, Matthew A. Russell, David L. Conlin, Larry E. Murphy, Donald L. Johnson, Brent M. Wilson, James D. Carr

Department of Chemistry: Faculty Publications

Current research on USS Arizona is focused on a minimum-impact technique for calculating corrosion rate of the battleship’s steel hull by analysing physical and chemical properties of marine encrustation covering the exposed hull. An equation is derived that allows concretion thickness, density, and total iron content to be used to calculate corrosion rate of steel hull plate.


Using Databases And Computational Techniques To Infer The Function Of Novel Proteins, Viswanathan Ramanathan, Kelly A. Mercier, Robert Powers, Peter Revesz May 2005

Using Databases And Computational Techniques To Infer The Function Of Novel Proteins, Viswanathan Ramanathan, Kelly A. Mercier, Robert Powers, Peter Revesz

Department of Chemistry: Faculty Publications

The Human Genome Project and similar efforts have resulted in the identification of an abundance of novel proteins. There is a need to expedite the process of assigning function to novel proteins. Nuclear magnetic resonance (NMR) spectroscopy can be used to infer a general biological function for a protein of unknown function by identifying compounds that preferentially bind the protein and comparing these results against proteins with defined structure and function. The Functional NMR screen generates hundreds of data sets and a manual analysis of these data sets is laborious and time- consuming. It is hypothesized that several sub-tasks of …


In Situ Screening To Optimize Variables In Organic Reactions, David Berkowitz, Mohua Bose, Sungjo Choi Jan 2005

In Situ Screening To Optimize Variables In Organic Reactions, David Berkowitz, Mohua Bose, Sungjo Choi

Department of Chemistry: Faculty Publications

A biphasic process for rapid screening of organic reactions comprising monitoring relative rates of parallel organic reactions. The screening process is suitable to determine the efficacy of different reactants, process conditions, and process enhancers such as catalysts or promoters. The biphasic process also allows multiple samples to be analyzed/monitored simultaneously. In addition because enzymes are used to monitor the reaction product in this invention, when that product is chiral and an enantio-discriminating enzyme is used to monitor the product, in addition to the relative rates, enantioselectivities of a set of parallel organic reactions can also be determined. The monitoring is …


In Situ Magnetoresistance Of Ni Nanocontacts, C-S Yang, Chunjuan Zhang, Jody G. Redepenning, Bernard Doudin Apr 2004

In Situ Magnetoresistance Of Ni Nanocontacts, C-S Yang, Chunjuan Zhang, Jody G. Redepenning, Bernard Doudin

Department of Chemistry: Faculty Publications

Magnetoresistance properties of Ni nanocontacts in the ballistic quantum regime are investigated in situ during closure and opening of electrochemically grown planar electrodes. The magnitude of conductance change when sweeping the magnetic field is of the order of the quantum conductance e2/h for conductance values spanning 1–100 quanta. The relative orientation of electric current and applied magnetic field changes the magnetoresistance sign, with symmetry properties reminiscent of bulk anisotropy magnetoresistance. Ex situ investigations of samples of higher conductance values, of the order of 1000 quanta, unambiguously show the analogy with bulk anisotropy magnetoresistance.


Magnesium/Methanol: An Effective Reducing Agent For Peroxides , Peng Dai, Patrick Dussault, Tony K. Trullinger Mar 2004

Magnesium/Methanol: An Effective Reducing Agent For Peroxides , Peng Dai, Patrick Dussault, Tony K. Trullinger

Department of Chemistry: Faculty Publications

Magnesium in methanol is an effective reagent for the chemoselective reduction of peroxides, including ozonides. Mg/MeOH is significantly more reactive than Me2S or PPh3 and somewhat more reactive than Zn/HOAc


Orientation And Bonding Of Biphenyldimethyldithiol, A. N. Caruso, R. Rajesh, Gordon A. Gallup, Jody G. Redepenning, Peter A. Dowben Feb 2004

Orientation And Bonding Of Biphenyldimethyldithiol, A. N. Caruso, R. Rajesh, Gordon A. Gallup, Jody G. Redepenning, Peter A. Dowben

Department of Chemistry: Faculty Publications

The molecular orbitals of 1, 1′-biphenyl-4,4′-dimethyldithiol (HS– CH2–C6H4–C6H4–CH2–SH) are identified from combined photoemission and inverse photoemission studies and compared with theory for several different surfaces, molecular conformations and molecular orientations. The preferential molecular orientations of biphenyldimethyldithiol, on both Au(111) and polycrystalline Co, are identified from polarization resolved photoemission studies. Two different molecular orientations are adopted by biphenyldimethyldithiol on gold depending on adsorption conditions. Biphenyldimethyldithiol is observed to bond more strongly to cobalt than gold surfaces.


Analysis Of Free Analyte Fractions By Rapid Affinity Chromatography, David S. Hage, William A. Clarke Jan 2004

Analysis Of Free Analyte Fractions By Rapid Affinity Chromatography, David S. Hage, William A. Clarke

Department of Chemistry: Faculty Publications

The invention is generally directed toward an analytical method to determine the concentration of the free analyte fraction in a sample. More particularly, the method encompasses applying a sample comprising a free and bound analyte fraction to an affinity column capable of selectively extracting the free fraction in the millisecond time domain. The signal generated by the free fraction is then quantified by standard analytical detection techniques. The concentration of the free fraction may then be determined by comparison of its signal with that of a calibration curve depicting the signal of known concentration of the same analyte.


Optimization Of Conditions For Studies Of Protein Unfolding By Hydrogen Exchange/Mass Spectrometry, A.S. Raza, David L. Smith Jan 2004

Optimization Of Conditions For Studies Of Protein Unfolding By Hydrogen Exchange/Mass Spectrometry, A.S. Raza, David L. Smith

Department of Chemistry: Faculty Publications

Understanding the forces driving protein folding and aggregation is an essential step in developing means for controlling these important processes. Amide hydrogen exchange, coupled with mass spectrometry, has become an important method for studying protein unfolding and refolding. To extend procedures developed to study unfolding of relatively soluble proteins to less soluble, aggregation-prone proteins requires special considerations. This publication describes a general strategy developed using yeast transaldolase, which aggregates easily under conditions required to study its unfolding. Results presented here show that reducing the protein concentration to the nanomolar range is essential for managing aggregation of transaldolase. In addition, the …