Physical Sciences and Mathematics Commons^™

Role Of Reactive Oxygen Species In Mercapto-Methylimidazole-Induced Gastric Acid Secretion And Stress-Induced Gastric Ulceration, Uday Bandyopadhyay, Dipak Das, Debasish Bandyopadhyay, Mrinalini Bhattacharjee, Ranajit K. Banerjee

Chemistry Faculty Publications and Presentations

The objective of the present study is to delineate the role of reactive oxygen species in drug-induced gastric hyperacidity and stress-induced gastric ulceration. We reported earlier that mercaptomethylimidazole (MMI), an antithyroid drug, induces gastric acid (HCl) secretion partially through H2receptor activation of the parietal cell by histamine release and partially through an intracellular mechanism. While studying the latter, MMI-induced acid secretion was found to correlate well with the inactivation of the peroxidase, an important H2O2metabolizing enzyme of the mucosa. MMI activates the isolated parietal cell for acid secretion, which is sensitive to omeprazole. Peroxidase and catalase activity of the isolated …

Capillary Electrophoresis/Tandem Mass Spectrometry With Array Detection, L.J. Deterding, K.B. Tomer, J.M.Y. Wellemans, Ronald Cerny, M.L. Gross

Ronald Cerny Publications

Mixtures of standard compounds of biological interest were analyzed by capillary electrophoresis in conjunction with tandem four sector mass spectrometry (MS/MS) using an array detector. Capillary electrophoresis offers extremely high separation efficiencies while array detection allows for the simultaneous acquisition of a large fraction of a tandem mass spectrum and high utilization of the sample ions produced. Consequently, improvements in sensitivity and structural information were observed for the combined techniques in comparison to similar measurements with a four-sector and a single-point detector. Coaxial continuous-flow fast atom bombardment was used to create (M + H) precursor ions of the separated analyses …

The Effect Of Carrier Gas Pressure On Vapor Phase Nucleation Experiments Using A Thermal Diffusion Cloud Chamber, D. Kane, S. P. Fisenko, M. Rusyniak, M. S. El-Shall

Chemistry Publications

Recent measurements of critical supersaturations for the vapor phase homogeneous nucleation of several substances using a diffusion cloud chamber technique exhibit a dependence on the pressure of the carrier gas used in the experiments. A model of droplet growth and motion in a diffusion cloud chamber, combined with the density and temperature profiles of the chamber is presented to explain the pressure dependent results. The model demonstrates that at higher carrier gas pressures the growth of the droplets is retarded and the optical scattering signal from the particles is reduced. It is concluded that the observed effect may not result …

Reproduction And Health Of A Beaver (Castor Canadensis) Population In Prince William County, Virginia, Timothy R. Brophy, Carl H. Ernst

Faculty Publications and Presentations

Reproduction and health were studied in a beaver (Castor canadensis) population from Prince William County, Virginia during 1998. Copulating beavers were observed in Quantico Creek at Prince William Forest Park on 22 January. Seven females from Quantico Marine Base were trapped between January and May, sacrificed, and dissected. Those reproductively active weighed over 39 pounds (17.7 kg) and were trapped before 1 March. Mean litter size based on counts of corpora lutea was 4.80 young (3-7); however, litter size based on the number of embryos present was only 2.75 (1-3), comparable to most others reported in the literature. Five of …

Application Of Geometric Probability Techniques To The Evaluation Of Interaction Energies Arising From A General Radial Potential, David Schleef, Michelle Parry, Shu-Ju Tu, Brian Woodahl, Ephraim Fischbach

Chemistry & Physics Faculty Publications

A formalism is developed for using geometric probability techniques to evaluate interaction energies arising from a general radial potential V(r₁₂), where r₁₂ = ∣r₂−r₁∣. The integrals that arise in calculating these energies can be separated into a radial piece that depends on r₁₂ and a nonradial piece that describes the geometry of the system, including the density distribution. We show that all geometric information can be encoded into a “radial density function” G(r₁₂;ρ₁,ρ₂), which depends on r_{12 …}

Relationship Between Udp-Glucose 4-Epimerase Activity And Oligoglucose Glycoforms In Two Strains Of Neisseria Meningitidis, F K. Lee, B W. Gibson, William Melaugh, A Zaleski, M A. Apicella

Chemistry Faculty Publications

Sodium dodecyl sulfate-polyacrylamide gel analysis of lipooligosaccharide (LOS) from Neisseria meningitidis has demonstrated considerable microheterogeneity in the variable region of LOS due to the presence of novel glycoforms. As a step toward understanding the basis for the expression of these novel glycoforms, we have examined the LOS structures and UDP-glucose 4-epimerase (epimerase) activity levels in two strains (NMB and MA-1) and their respective galE mutants. Strain NMB was found to have low epimerase activity and to contain multiple glycoforms, some of which appear to contain only glucose sugars. The galE mutant had only the oligoglucose glycoforms. Strain MA-1 had higher …

Experimental And Theoretical Investigations Of The Structure And The Stability Of The Bnsi Molecule, Giovanni Meloni, R Viswanathan

Chemistry Faculty Publications

Theoretical computations were carried out to determine the structure and molecular parameters of the BNSi molecule. The most stable isomer is found to have a BNSi linear geometry. Thermal functions as derived from the theoretical computed molecular parameters were used in the evaluation of the thermodynamic properties of BNSi from high-temperature Knudsen effusion mass spectrometric equilibrium data. From the reactions analyzed by the second-law and third-law methods, the enthalpy of formation,ΔfHo0, and of atomization, ΔaHo0, in kJ mol⁻¹, for BNSi, were obtained as 398±16 and 1078±17, respectively.

Thermodynamic Investigation Of The Ainc And Aicn Isomers By Knudsen Cell Mass Spectrometry, Giovanni Meloni, Karl A. Gingerich

Chemistry Faculty Publications

Equilibria involving the isomers AlNC and AlCN above a mixture of aluminum nitride, graphite, and gold contained in a graphite Knudsen cell were investigated with a mass spectrometer. The enthalpies of formation,ΔfHo0, and of atomization, ΔaHo0, in kJ mol⁻¹, for AlNC and AlCN, were derived as 281.3±14 and 303.8±14, and as 1228.1±15 and 1205.6±15, respectively.

Molecular Composition Of The Louse Sheath, Craig N. Burkhart, B Artur Stankiewicz, Irene Pchalek, Michael A. Kruge, Craig G. Burkhart

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Flash pyrolysis-gas chromatography/mass spectrometry was used to assess the chemical composition of the head louse's nit sheath. The pyrolyzate of the female insect's secretions, which form a cement-like cylinder holding the egg onto the hair, is dominated by amino acid derivatives and fatty acids. No chitin-specific compounds were detected in the sheath. These results, contrary to previous reports, show that the polymeric complex of the sheath is composed of proteinaceous moieties, possibly cross-linked to aliphatic components. This study constitutes the first chemical characterization of the pyrolysis products of insect (louse) glue and unequivocally confirms that louse sheaths are not chitinous, …

Classification Of Torbanite And Cannel Coal. Ii. Insights From Organic Geochemical And Multivariate Statistical Analysis, Zhiwen Han, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Petrographic and megascopic criteria have traditionally been used as the basis for the classification of torbanite and cannel coal. For this study, it was hypothesized that modern analytical organic geochemical and multivariate statistical techniques could provide an alternative approach. Towards this end, the demineralized residues of 14 torbanite (rich in Botryococcus-related alginite) and cannel (essentially, rich in organic groundmass and/or sporinite) coal samples were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Cluster analysis performed on the Py-GC/MS data clearly distinguished the torbanite from the cannel coal, demonstrating a consistency between the chemical properties and the petrographic composition. All the torbanite …

Iron-Induced Oxidative Stress In Erythrocyte Membranes Of Non-Insulin-Dependent Diabetic Nigerians, Gbolahan W. Okunade, Odutayo O. Odunuge, Olufunso O. Olorunsogo

Faculty Publications

The presence of higher level of endogenous free radical reaction products in the erythrocyte ghost membrane (EGM) of Non-insulin-dependent diabetes mellitus (NIDDM) subjects compared with that of normal healthy controls has been demonstrated. The EGMs of NIDDM subjects were also shown to be more susceptible to exogenously generated oxidative stress than those of normal healthy individuals. The decreased level of reactive thiol groups in the EGM of NIDDM individuals supported this observation. We propose that the presence of significant levels of non-heme iron in the EGM of NIDDM subjects is an indication of the potential for iron-catalysed production of hydroxy …

Reversal Of Sodium Arsenite Inhibition Of Rat Liver Microsomal Ca2+ Pumping Atpase By Vitamin C, Odutayo O. Odunuge, Gbolahan W. Okunade, Olufunso O. Olorunsogo

Faculty Publications

Sodium arsenite (NaAsO2), at 10% of its median lethal dose, was administered to rats with and without vitamin C pretreatment. Liver microsomal fraction was isolated and the activity of Ca2+-ATPase was assayed. Sodium arsenite was found to inhibit the activity of the liver microsomal Ca2+-ATPase to 50% to that of control rats. The specific activity of the enzyme in rats administered sodium arsenite with vitamin C pretreatment was not significantly different from that of control rats.

Affinity Chromatography: A Review Of Clinical Applications, David S. Hage

David Hage Publications

Affinity chromatography is a type of liquid chromatography that makes use of biological-like interactions for the separation and specific analysis of sample components. This review describes the basic principles of affinity chromatography and examines its use in the testing of clinical samples, with an emphasis on HPLCbased methods. Some traditional applications of this approach include the use of boronate, lectin, protein A or protein G, and immunoaffinity supports for the direct quantification of solutes. Newer techniques that use antibody-based columns for on- or off-line sample extraction are examined in detail, as are methods that use affinity chromatography in combination with …

Classification Of Explosives Transformation Products In Plant Tissue, Steven L. Larson, Robert P. Jones, Lynn Escalon, Don Parker

US Army Corps of Engineers

Explosives contamination in surface or groundwater used for the irrigation of food crops and phytoremediation of explosives-contaminated soil or water using plant-assisted biodegradation have brought about concerns as to the fate of explosives in plants. Liquid scintillation counting, high-performance liquid chromatography, and gel permeation chromatography were utilized to characterize explosives (hexahydro-1,3,5-trinitro-1,3,5-triazine and trinitrotoluene) and their metabolites in plant tissues obtained from three separate studies. Analyzing tissues of yellow nutsedge (Cyperus esculentus), corn (Zea mays), lettuce (Lacuta sativa), tomato (Lyopersicum esculentum), radish (Raphanus sativus), and parrot feather (Myriophyllum aquaticum) …

Resistivity, Thermopower And The Correlation To Infrared Active Vibrations Of Mn1.56co0.96ni0.48o4 Spinel Films Sputtered In An Oxygen Partial Pressure Series, Rand Dannenberg, S. Baliga, R. J. Gambino, Alexander H. King, A. P. Doctor

Alexander H. King

Mn1.56Co0.96Ni0.48O4 spinel was sputter deposited using a series of oxygen partial pressures. Electrical resistivity versus temperature and thermopower versus temperature measurements at each oxygen partial pressure were made. The variations of the thermopower and resistivity with oxygen partial pressure are consistent with a change in the ratio of Mn3+ to Mn4+ cations, which occurs due to changes of oxygen content of the material. The weak temperature dependence of the thermopower indicates small polaron hopping is the charge transport mechanism. Combining the models of Mott and Schnakenberg to analyze the transport data, we find that the Debye temperature (or frequency) is …

The Β Effect Of Silicon And Related Manifestations Of Σ Conjugation, Joseph B. Lambert, Yan Zhao, Robert W. Emblidge, Lourdes A. Salvador, Xiaoyang Liu, Jeung-Ho So, Erik C. Chelius

Yan Zhao

Stabilization of carbocations through donation of ð electrons from adjacent carbon orbitals results in well-known species such as the allyl and benzyl cations. Adjacent nonbonding (n) electrons on heteroatoms also can provide considerable stabilization, as in oxonium ions such as CH2dO+CH3 and iminium ions such as CH2dN+(CH3)2. Less well known is stabilization of carbocations by ó orbitals. In its most common example this interaction provides stabilization of tertiary over secondary over primary carbocations. According to the valence bond representation of this interaction, a filled ó orbital donates electrons to an empty ð orbital, as in 1 and 2 (R ) …

Infrared Optical Properties Of Mn1.56co0.96ni0.48o4 Spinel Films Sputter Deposited In An Oxygen Partial Pressure Series, Rand Dannenberg, S. Baliga, R. J. Gambino, Alexander H. King, A. P. Doctor

Alexander H. King

Mn1.56Co0.96Ni0.48O4 spinel films were sputter deposited onto silicon substrates using a series of oxygen partial pressures. Fourier transform infrared transmission and reflectance, and Raman scattering measurements were made. The 1–25 μm wavelength range was examined using these optical techniques. The complex index of refraction was calculated for this entire wavelength range. Infrared active vibrations were analyzed using multiple oscillator analysis, Kramers–Kronig analysis, and derivative reflectance spectroscopy. The Raman and infrared active lattice vibrations were observed to shift with increasing oxygen partial pressure during film deposition, and were consistent with the earlier published shift in Debye frequency calculated from resistivity data. …

The He-Lih Potential Energy Surface Revisited. I. An Interpolated Rigid Rotor Surface, Robert Hinde

Robert Hinde

We reconsider the potential energy surface of the He–LiH system recently examined by Gianturco and co-workers [F. A. Gianturco et al., Chem. Phys. 215, 227 (1997)]. We compute the He–LiH interaction energy at the CCSD(T) level using large correlation consistent atomic basis sets supplemented with bond functions. To capture the severe anisotropy of the He–LiH potential, we interpolate our ab initio points in the angular direction with cubic splines, then expand the splines in terms of Legendre polynomials. The resulting smooth potential surface differs substantially from that of Gianturco et al.; in particular, our attractive He–LiH well is more …

Chemistry Reform Takes Root In University Settingeforms In Mathematics And Science, Thomas Pentecost

Peer Reviewed Articles

Which of the following scenarios is more attractive?

(1) You arrive for chemistry class and listen and watch an

instructor work problems about gas laws for fifty minutes.

(2) You arrive for class and you and a few other classmates anake

data about the relationship between pressure and volume and develop

the gas laws based on data.

A Biogeochemical Comparison Of Fossil (Carboniferous) And Modern Crustose Red Algae, Michael A. Kruge, John E. Utgaard, William Ferry

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The nature of the contribution of the various types of algae to sedimentary organic matter continues to be a topic of research interest. Crustose red algae have however received less attention than other types. The fossil calcareous red algae (Rhodophyta) analyzed in this study are two relatively unrecrystallized specimens of Parachaetetes (Family Solenoporacea) from the lower part of the Ste. Genevieve Formation (Carboniferous, Visean) in Union County, Illinois, USA. They occurred in the patch reef phase of a small carbonate mudmound-patchreef. The three modern specimens (collected and identified by F. Collier) are the crustose algae Lithothamnion, Clathromorphum and Phymatolithon …

Cubane Tetrameric Complexes Of Copper(I) Chloride And Bromide With Triphenyl Phosphite, Robert D. Pike, William H. Starnes Jr., Gene B. Carpenter

Arts & Sciences Articles

The crystal structures of tetra-/z3-chloro-tetrakis[(triphenyl phosphite-P)copper(I)], [CunC14(CI8HI503P)4], and tetra-#3-bromo-tetrakis [ (triphenyl phosphite-P) - copper(I)], [Cu4Br4(CI8H1503P)4], are described. Both have distorted 'cubane' CuaX4 cores. Distortion of the cubane structure is reflected in X--Cu--X angles > 90 ° and Cu--X--Cu angles < 90 °, and is more pronounced in the bromide complex.

The He-Lih Potential Energy Surface Revisited. I. An Interpolated Rigid Rotor Surface, Robert Hinde

Chemistry Publications and Other Works

We reconsider the potential energy surface of the He–LiH system recently examined by Gianturco and co-workers [F. A. Gianturco et al., Chem. Phys. 215, 227 (1997)]. We compute the He–LiH interaction energy at the CCSD(T) level using large correlation consistent atomic basis sets supplemented with bond functions. To capture the severe anisotropy of the He–LiH potential, we interpolate our ab initio points in the angular direction with cubic splines, then expand the splines in terms of Legendre polynomials. The resulting smooth potential surface differs substantially from that of Gianturco et al.; in particular, our attractive He–LiH well is more …

On-Road Remote Sensing Of Automobile Emissions In The Phoenix Area: Year 1, Gary A. Bishop, Sajal S. Pokharel, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Identification Of Polluting Vehicles By Remote Sensing, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

A Theoretical Study Of The Electronic Coupling Element For Electron Transfer In Water, Newt E. Miller '99, Matthew C. Wander '97, Robert J. Cave

All HMC Faculty Publications and Research

The electronic coupling element for electron transfer between a donor and acceptor in water is examined using simulations combining molecular dynamics and semiempirical quantum mechanics. In the first phase of the simulations a model donor and acceptor are solvated in water, using realistic potentials. Following equilbration, molecular dynamics simulations are performed with the donor, acceptor, and water at approximately 300 K, under periodic boundary conditions. In the second phase of the simulation, the electronic coupling element between the donor and acceptor is calculated for a number of time slices, in the presence of the intervening water molecules (those having a …

Observation And Application Of Optical Interference And Diffraction Effects In Reflection From Photochemically Fabricated Gaussian Interfaces, Lynne Koker, Kurt W. Kolasinski

Chemistry Faculty Publications

No abstract provided.

Characterisation And Optimisation Of Gypsum Crystallization, Catherine H. Shannon

Theses

Gypsum is produced as a by-product during the citric acid production process at ADM Ringaskiddy. The particle size and filterability of the gypsum has a critical bearing on the overall citric acid production rate. Prior to August 1996, research in the area of gypsum crystal optimisation at ADM had concentrated on the application of vortex mixing to perform the gypsum formation reaction. While the gypsum crystals produced with vortex mixing were found to be desirably clear of microcrystalline gypsum, the crystals were considerably smaller and more difficult to filter and wash. This research project sought to retain the advantages conferred …

Optimisation Studies In A Batch Pharmaceutical Company, Sarah Fitzgerald

Theses

This thesis outlines a collaborative project between industry and academia based on a short term research contract.

In the past in Eli Lilly, process optimisation in a multi-purpose, modular building had been mainly confined to equipment commissioning and new product development. It was necessary to embark upon an exercise to develop an optimisation programme m order to meet the increased requirements and demands of the building. Increased market demands, through the introduction of over-the-counter (OTC) drugs, and the demand for cycle time reduction through the expiry of existing patents, made the need for optimisation inevitable.

The purpose of this thesis …

Thermal Characterization Of Pmma Thin Films On Silica Using Modulated Differential Scanning Calorimetry, Crystal E. Porter, Frank D. Blum

Chemistry Faculty Research & Creative Works

The number of studies of thin polymer films has increased over recent years as technological processes incorporate the use of nanomaterials. An enhanced understanding of these films would enable us to predict bound-polymer behavior and thus improve the efficiency of processes and the quality of products. This is especially true as the thickness of the films approach molecular dimensions. The glass transition temperature of a polymer is one of the most important properties for characterization because it indicates how the polymer might perform macroscopically. when a polymer is confined, such as one the surface of a substrate, its behavior is …

Soft X-Ray Photochemistry At The L₂,₃-Edges In K₃[Fe(Cn)₆], [Co(Acac)₃] And [Cp₂Fe][Bf₄], David Collison, Catherine David Garner, Catherine M. Mcgrath, J. Fred Willem Mosselmans, Mark D. Roper, Jon M. W Seddon, Ekkehard Sinn, Nigel A. Young

Chemistry Faculty Research & Creative Works

Soft X-ray photoreduction has been observed in K3[Fe(CN)6], [Co(acac)3] and [Cp2Fe][BF4].