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Articles 2551 - 2580 of 2757

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Reversal Of Sodium Arsenite Inhibition Of Rat Liver Microsomal Ca2+ Pumping Atpase By Vitamin C, Odutayo O. Odunuge, Gbolahan W. Okunade, Olufunso O. Olorunsogo Jan 1999

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.


Cyclopropane Fatty Acid Expression In Plants, Katherine M. Schmid Jan 1999

Cyclopropane Fatty Acid Expression In Plants, Katherine M. Schmid

Scholarship and Professional Work - LAS

Pants [sic] are transformed with a bacterial cyclopropane fatty acid synthase gene to produce lipids containing cyclopropane fatty acids. Using this technology dihydrosterculate is produced in oilseed crops such as rape.


A Biogeochemical Comparison Of Fossil (Carboniferous) And Modern Crustose Red Algae, Michael A. Kruge, John E. Utgaard, William Ferry Jan 1999

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 …


Some Aspects Of The Adsorption Of A Lennard-Jones Gas On A Rough Surface, Douglas Henderson, Pawel Bryk, Stefan Sokolowski Jan 1999

Some Aspects Of The Adsorption Of A Lennard-Jones Gas On A Rough Surface, Douglas Henderson, Pawel Bryk, Stefan Sokolowski

Faculty Publications

We study the adsorption, including wetting, of a Lennard-Jones gas on a rough surface consisting of rough layer on a smooth substrate with which the gas interacts via a 9-3 potential. The rough layer is two molecular diameters thick and consists of a disordered quenched matrix of hard spheres. As well as interacting with the other matrix spheres by the hard-sphere potential, the matrix molecules interact with the gas molecules by the hard-sphere potential. Hence, on average, the degree to which the gas molecules can approach the substrate depends only on the density of the matrix layer. The density of …


The Atomic Force Microscope In The Elucidation Of Leukocyte Abnormality, Derbrenn O'Connor Jan 1999

The Atomic Force Microscope In The Elucidation Of Leukocyte Abnormality, Derbrenn O'Connor

Theses

The aim of this project was to investigate the novel use of the atomic force microscope (AFM) as a technique in the elucidation of leukocyte abnormality. To this end, comparative AFM imaging and elasticity studies were performed on normal and myeloid leukaemic leukocytes.

Initially, an evaluation of techniques for the isolation of specific leukocyte (e.g. lymphocytes, granulocytes, etc.) populations from whole blood or leukocyte concentrates, was carried out. It was found that a silanised glass surface failed to select and immobilise a leukocyte population. However, centrifugation of whole blood in an Isopaque-ficoll gradient solution yielded a viable mixed leukocyte population …


Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt Jan 1999

Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt

Journal of the Arkansas Academy of Science

Phytoestrogens are biochemicals synthesized in plants which mimic steroidal estrogen activity in mammals. Analysis of these compounds in the legumes which produce them and in body fluids is important to the study of their physiological effects. High pressure liquid chromatography (HPLC) has been found to be an efficient and sensitive method of identification and quantitation of isoflavonoids, one class of phytoestrogen. Here we report the separation of three isoflavonoids, biochanin A, genistein and daidzein using an HPLC system with a Cg reverse phase column and a linear gradient mobile phase containing acetonitrile and acetic acid/water (10/90, v/v) over 60 minutes. …


Two-Photon Excitation Of Rhenium Metal-Ligand Complexes, Joseph R. Lakowicz, Felix N. Castellano, Ignacy Gryczynski, Zygmunt Gryczynski, Jonathan D. Dattelbaum Jan 1999

Two-Photon Excitation Of Rhenium Metal-Ligand Complexes, Joseph R. Lakowicz, Felix N. Castellano, Ignacy Gryczynski, Zygmunt Gryczynski, Jonathan D. Dattelbaum

Chemistry Faculty Publications

We describe the emission spectral properties of two rhenium metal-ligand complexes with one and two-photon excitation, Re(bpy)2(CO)3Cl and [Re(bpy)(CO)3CH3CN]+, where bpy is 2,2’-bipyridyl and CH3CN is acetonitrile. Similar emission spectra and intensity decay times characteristic of the metal-to-ligand charge transfer state were observed for one- and two-photon excitation. The lifetime and quantum yield of the acetonitrile complex are approximately 14-fold higher than that of the chloride complex. Both complexes display high anisotropies near 0.33 in frozen solution with one-photon excitation. Two-photon excitation results in anisotropies about 40% larger, …


Affinity Chromatography: A Review Of Clinical Applications, David S. Hage Jan 1999

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 …


Investigating The Allosteric Behavior Of Malate Dehydrogenase From Escherichia Coli, Eman M. Ghanem Jan 1999

Investigating The Allosteric Behavior Of Malate Dehydrogenase From Escherichia Coli, Eman M. Ghanem

Masters Theses

Regulatory mechanisms of malate dehydrogenase from E.coli (eMDH) involving NADH as an allosteric effector were investigated. The reaction was studied in both directions: malate oxidation and oxaloacetate reduction. When malate was the variable substrate, a plot of rate against substrate concentration was sigmoidal in the presence of 0.065 mM NADH, which indicates the presence of an allosteric site for NADH on the enzyme. Binding of NADH at the allosteric site causes conformational changes in the active site and, thereby, changes the catalytic activity of the enzyme. An increase in Km value, from 1.3 to 3.9 mM malate was observed, …


Phorbol 12-Myristate 13-Acetate Stimulates Lysophosphatidic Acid Secretion From Ovarian And Cervical Cancer Cells But Not From Breast Or Leukemia Cells, Zhongzhou Shen, Jerome Belinson, Richard E. Morton, Yan Xu Dec 1998

Phorbol 12-Myristate 13-Acetate Stimulates Lysophosphatidic Acid Secretion From Ovarian And Cervical Cancer Cells But Not From Breast Or Leukemia Cells, Zhongzhou Shen, Jerome Belinson, Richard E. Morton, Yan Xu

Chemistry Faculty Publications

Lysophosphatidic acid (LPA) is present in ascites from patients with ovarian cancer. It stimulates calcium release and growth of ovarian cancer cells bothin vitroandin vivo.Recently, we found that LPA levels were significantly elevated in plasma from patients with ovarian cancer and other gynecological cancers. In contrast, LPA levels were not elevated in patients with breast cancer and leukemias. In view of this, we investigated whether gynecological cancer cells could produce LPA. LPA was extracted from the supernatant of cells culturedin vitroand purified by thin layer chromatography. After hydrolysis and transmethylation, the fatty acid derivatives were analyzed by gas chromatography. We …


Principal Component Mapping Applied To Raman Microspectroscopy Of Fiber-Reinforced Polymer Composites, C. M. Stellman, K. S. Booksh, A. R. Muroski, M. P. Nelson, Michael L. Myrick Dec 1998

Principal Component Mapping Applied To Raman Microspectroscopy Of Fiber-Reinforced Polymer Composites, C. M. Stellman, K. S. Booksh, A. R. Muroski, M. P. Nelson, Michael L. Myrick

Faculty Publications

We describe the development and implementation of a spectroscopic Raman imaging system using Principal Component data analysis. Raman microspectroscopy followed by multivariate data analysis and principal component mapping has been used to investigate the spatial variations of chemical and physical properties at interfaces in glass-reinforced composites on the micrometer scale. A protocol for monitoring chemical and physical variances via multivariate statistics has been developed and a preliminary study of a "real world" glass-reinforced composite is presented. It is demonstrated that multivariate Raman imaging is more precisely interpretable than traditional univariate methods and that by appropriately choosing distinct spectral regions (such …


Dynamics Of Biomolecules: Assignment Of Local Motions By Fluorescence Anisotropy Decay, Carl N. Bialik, Barnabas Wolf, Edward L. Rachofsky, J. B. A. Ross, William Laws Nov 1998

Dynamics Of Biomolecules: Assignment Of Local Motions By Fluorescence Anisotropy Decay, Carl N. Bialik, Barnabas Wolf, Edward L. Rachofsky, J. B. A. Ross, William Laws

Chemistry and Biochemistry Faculty Publications

Many biological systems have multiple fluorophores that experience multiple depolarizing motions, requiring multiple lifetimes and correlation times to define the fluorescence intensity and anisotropy decays, respectively. To simplify analyses, an assumption often made is that all fluorophores experience all depolarizing motions. However, this assumption usually is invalid, because each lifetime is not necessarily associated with each correlation time. To help establish the correct associations and recover accurate kinetic parameters, a general kinetic scheme that can examine all possible associations is presented. Using synthetic data sets, the ability of the scheme to discriminate among all nine association models possible for two …


Monte Carlo Simulation Of An Ion-Dipole Mixture As A Model Of An Electrical Double Layer, Douglas Henderson, Dezso Boda, Kwong-Yu Chan Nov 1998

Monte Carlo Simulation Of An Ion-Dipole Mixture As A Model Of An Electrical Double Layer, Douglas Henderson, Dezso Boda, Kwong-Yu Chan

Faculty Publications

Canonical Monte Carlo simulations were performed for a nonprimitive model of an electrical double layer. The ions and the solvent molecules are modeled as charged and dipolar hard spheres, respectively, while the electrode as a hard, impenetrable wall carrying uniform surface charge. We found that the ion-dipole model gives a reasonable description of the double layer for partially charged ions with small to moderate dipole moments, or equivalently for an "effective" dielectric constant. Density, polarization and mean electrostatic potential profiles are reported. Strong layering structure, and at higher charges, charge inversion in the second layer were found. With appropriate choices …


Interagency Lake Mead And Las Vegas Wash Monitoring Program: Standard Operating Procedures Manual, Bureau Of Reclamation, City Of Henderson Water Reclamation Facility, City Of Las Vegas Water Pollution Control Facility, Clark County Sanitation District, Nevada, Southern Nevada Water Authority Oct 1998

Interagency Lake Mead And Las Vegas Wash Monitoring Program: Standard Operating Procedures Manual, Bureau Of Reclamation, City Of Henderson Water Reclamation Facility, City Of Las Vegas Water Pollution Control Facility, Clark County Sanitation District, Nevada, Southern Nevada Water Authority

Publications (WR)

A number of agencies sample Lake Mead and the Las Vegas Wash on a routine basis at several locations. In order to share and properly interpret the data, the Bureau of Reclamation, Southern Nevada Water Authority and the three Wastewater Treatment Facilities (City of Las Vegas, Clark County Sanitation District and City of Henderson) formed a committee to examine sampling and analytical protocols and to share information with the goal of maximizing the data quality. The group first met in April 1997. It was agreed that an effort should be made to discuss and compare specific sampling and analytical techniques …


Simultaneous Formation Of Functional Leading And Lagging Strand Holoenzyme Complexes On A Small, Defined Dna Substrate, Anthony J. Berdis, Stephen J. Benkovic Sep 1998

Simultaneous Formation Of Functional Leading And Lagging Strand Holoenzyme Complexes On A Small, Defined Dna Substrate, Anthony J. Berdis, Stephen J. Benkovic

Chemistry Faculty Publications

The biochemical characterization of leading and lagging strand DNA synthesis by bacteriophage T4 replication proteins has been addressed utilizing a small, defined primer/template. The ATP hydrolysis activity of 44/62, the clamp loading complex responsible for holoenzyme assembly, was monitored during assembly of both the leading and lagging strand holoenzyme complex. The ATPase activity of 44/62 diminishes once a functional holoenzyme is assembled on both the leading and lagging strand. The assembly of the lagging strand holoenzyme is facilitated by several factors including biotinylated streptavidin blocks at the end of the fork strands, preassembly of the leading strand holoenzyme, and by …


Localization Of Sodium, Potassium-Adenosine Triphosphatase In The Cerebral Cortex Of Developing Rats, Maki Ujiie Sep 1998

Localization Of Sodium, Potassium-Adenosine Triphosphatase In The Cerebral Cortex Of Developing Rats, Maki Ujiie

Loma Linda University Electronic Theses, Dissertations & Projects

Active transport via Na+, K+-ATPase plays an important role in establishing and maintaining proper ionic gradient across all mammalian cell membranes. A strict regulation of Na+, and K+ ion levels is especially important in excitable cells such as neurons and myocytes. Inhibition of the enzyme is associated with several pathological conditions and has serious detrimental effects on cerebral cortical cells. Yet the enzyme appears to be limited in amount and distribution in newborn rats. In this study, Na+, K+- ATPase expression and distribution in early postnatal rats were studied …


Solute-Solvent Pair Distribution Functions In Highly Asymmetric Additive Hard Sphere Mixtures, Douglas Henderson, Kwong-Yu Chan Jun 1998

Solute-Solvent Pair Distribution Functions In Highly Asymmetric Additive Hard Sphere Mixtures, Douglas Henderson, Kwong-Yu Chan

Faculty Publications

Contact values for the solute-solvent pair distribution function in an additive hard sphere mixture, as computed from the Henderson-Chan (HC) formulas, are compared with the recent Monte Carlo (MC) data and formula of Matyushov and Ladanyi (ML) [J. Chem. Phys. 107, 5815 (1997)]. The agreement is found to be excellent. The negative finding of ML is due to a misprint in one of the HC publications. We find the HC formula to be superior to the ML formula when compared to our MC data [Mol. Phys. 91, 1137 (1997)] for the case where the ratio of diameters is large and …


Influences Of Acid Mine Drainage On Water Chemistry Of Blackwater River Watershed, Carla C. Morato-Lara Jan 1998

Influences Of Acid Mine Drainage On Water Chemistry Of Blackwater River Watershed, Carla C. Morato-Lara

Theses, Dissertations and Capstones

Acidic mine drainage flow from active and abandoned coal mines has been a major source of water pollution in the Appalachian Mountain region of the eastern USA. Water samples were collected and analyzed from Blackwater River watershed during 2 years (September 1996 - May 1998). The water quality measurements determined that the Beaver Creek and North Fork tributaries were affected by acid mine drainage but not Yellow Creek. Beaver Creek and North Fork stations had high sulfate and manganese markers of acid mine drainage, whereas Yellow Creek was slightly acidic with low sulfate and manganese. North Fork was the primary …


Vibrational Sum Frequency Spectroscopy Of Surfactants And Phospholipids Monolayers At Liquid-Liquid Interfaces, B. L. Smiley, R. A. Walker, D. E. Gragson, T. E. Hannon, G. L. Richmond Jan 1998

Vibrational Sum Frequency Spectroscopy Of Surfactants And Phospholipids Monolayers At Liquid-Liquid Interfaces, B. L. Smiley, R. A. Walker, D. E. Gragson, T. E. Hannon, G. L. Richmond

Chemistry and Biochemistry

Work from our laboratory on vibrational sum frequency spectroscopic investigations of molecular ordering at the carbon tetrachloride-water interface is reviewed. Simple charged surfactants adsorbed at the liquid-liquid interface are seen to induce alignment of interfacial water molecules to a degree which is dependent on the induced surface potential. Saturation of water molecule alignment occurs at a surfactant surface concentration corresponding to a calculated surface potential of approximately 160 mV. In complementary studies, the relative degree of hydrocarbon chain ordering within monolayers of symmetric phosphatidylcholines of different chain lengths is inferred by the relative signal contributions of the methyl and methylene …


The Biogeochemical Cycling Of Dissolved Organic Nitrogen In Estuarine Sediments, David J. Burdige, Shilong Zheng Jan 1998

The Biogeochemical Cycling Of Dissolved Organic Nitrogen In Estuarine Sediments, David J. Burdige, Shilong Zheng

OES Faculty Publications

Benthic fluxes and pore-water profiles of dissolved organic nitrogen and carbon (DON and DOC, respectively) were determined in seasonal studies at contrasting sites in Chesapeake Bay. Pore-water dissolved organic matter (DOM) concentrations were elevated over bottom-water values, generally increased with depth, and ranged from 15 to similar to 160 μM for DON and ~200-2000 μM for DOC. Pore-water DOM concentrations and the C:N ratio of this material showed spatial (depth) and temporal changes that varied among the sites studied. These trends appeared to be related to differences in the types of sediment organic matter (SOM) undergoing remineralization, as well as …


Iron In Ice Cores From Law Dome, East Antarctica: Implications For Past Deposition Of Aerosol Iron, R. Edwards, Peter N. Sedwick, Vin Morgan, C. F. Boutron, S. Hong Jan 1998

Iron In Ice Cores From Law Dome, East Antarctica: Implications For Past Deposition Of Aerosol Iron, R. Edwards, Peter N. Sedwick, Vin Morgan, C. F. Boutron, S. Hong

OES Faculty Publications

Total-dissolvable iron has been measured in sections of three ice cores from Law Dome, East Antarctica, and the results used to calculate atmospheric iron deposition over this region during the late Holocene and to provide a preliminary est. of aerosol iron deposition during the Last Glacial Maximum (LGM). Ice-core sections dating from 56-2730 BP (late Holocene) and ∼18 000 BP (LGM) were decontaminated using trace-metal clean techniques, and total-dissolvable iron was determined in the acidified meltwaters by flow-injection analysis. Our results suggest that the atmospheric iron flux onto the Law Dome region has varied significantly over time-scales ranging from seasonal …


Evaluation Of Toxicity, Bioavailability And Speciation Of Lead, Zinc And Cadmium In Mine/Mill Wastewaters, Mujde Erten-Unal, Bobby G. Wixson, Nord Gale, Jerry L. Pitt Jan 1998

Evaluation Of Toxicity, Bioavailability And Speciation Of Lead, Zinc And Cadmium In Mine/Mill Wastewaters, Mujde Erten-Unal, Bobby G. Wixson, Nord Gale, Jerry L. Pitt

Civil & Environmental Engineering Faculty Publications

The toxicity of common compounds of lead, cadmium and zinc was evaluated in waters similar to that found in the world's largest lead producing area in Missouri. Static, acute toxicity tests were performed using fathead minnows (Pimephales promelas) and water fleas (Daphnia magna) respectively. Test organisms were subjected to varying amounts of sulfide, carbonate, chloride and sulfate salts of lead, zinc and cadmium mixed in hard, alkaline waters typical to this region. Median lethal concentrations were calculated using nominal versus measured metal concentrations. Measured metal concentrations included four different metal fractionation (extraction/filtration) techniques at different pH …


1080 Operational Procedures Manual - Second Edition, Agriculture Western Australia Jan 1998

1080 Operational Procedures Manual - Second Edition, Agriculture Western Australia

Biosecurity published reports

Sodium fluoroacetate (1080) is an extremely toxic substance which can be a danger to humans if handled incorrectly. At the same time 1080 is the most effective and efficient poison for the control of Western Australia's main vertebrate pest species including rabbits, wild dogs and foxes. One of the main reasons for its usefulness in Western Australia is that many native animals have a high tolerance to it and so may not be affected by baiting.

Industry Resource Protection Program (IRPP) This program, part of Agriculture Western Australia, supports feral animal control carried out by its staff and community groups. …


Probing The Intermolecular Hydrogen Bonding Of Water Molecules At The Ccl4/Water Interface In The Presence Of Charges Soluble Surfactant, D. E. Gragson, G. L. Richmond Dec 1997

Probing The Intermolecular Hydrogen Bonding Of Water Molecules At The Ccl4/Water Interface In The Presence Of Charges Soluble Surfactant, D. E. Gragson, G. L. Richmond

Chemistry and Biochemistry

The molecular structure and hydrogen bonding of water molecules at the CCl4/water interface in the presence of a charged soluble surfactant has been explored in this study using vibrational sum frequency generation. By examining OH stretching modes that are highly sensitive to the local hydrogen bonding environment it is found that water molecules at the CCl4/water interface both in the presence and absence of a charged soluble surfactant are predominantly in a tetrahedral arrangement much like the structure ofice. Isotopic dilution studies have been employed to further characterize this icelike interfacial structure. Ablueshift ofapproximately120 cm-1 …


Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell Oct 1997

Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Some binary lipid mixtures form coexisting liquid phases when spread at the air/water interface. This work describes the pressure–composition phase diagrams of binary mixtures of four unsaturated phosphatidylcholines with dihydrocholesterol. These four binary mixtures have critical compositions of approximately fifty mole percent, and average critical exponents of 0.25±0.07. The data can also be approximated by a regular solution thermodynamic model, yielding parameters for the non-ideality of these mixtures.


A Fluid In Contact With A Semipermeable Surface: Second-Order Integral Equation Approach, Douglas Henderson, Pawel Bryk, Stefan Sokolowski Aug 1997

A Fluid In Contact With A Semipermeable Surface: Second-Order Integral Equation Approach, Douglas Henderson, Pawel Bryk, Stefan Sokolowski

Faculty Publications

An integral equation approach for a binary hard-sphere mixture interacting with a planar semipermeable wall (membrane) is formulated by using the second-order nonuniform or pair Ornstein–Zernike equation as well as the usual singlet Ornstein–Zernike equation. The results of the pair theory are compared with those obtained from the singlet theory and with computer simulation data. The pair approach is more accurate than the singlet theory.


Emissions From Smoldering Combustion Of Biomass Measured By Open-Path Fourier Transform Infrared Spectroscopy, Robert J. Yokelson, Ronald A. Susott, Darold E. Ward, James J. Reardon, David W. T. Griffith Aug 1997

Emissions From Smoldering Combustion Of Biomass Measured By Open-Path Fourier Transform Infrared Spectroscopy, Robert J. Yokelson, Ronald A. Susott, Darold E. Ward, James J. Reardon, David W. T. Griffith

Chemistry and Biochemistry Faculty Publications

Biomass samples from a diverse range of ecosystems were burned in the Intermountain Fire Sciences Laboratory open combustion facility. Midinfrared spectra of the nascent emissions were acquired at several heights above the fires with a Fourier transform infrared spectrometer (FTIR) coupled to an open multipass cell. In this report, the results from smoldering combustion during 24 fires are presented including production of carbon dioxide, carbon monoxide, methane, ethene, ethyne, propene, formaldehyde, 2-hydroxyethanal, methanol, phenol, acetic acid, formic acid, ammonia, hydrogen cyanide, and carbonyl sulfide. These were the dominant products observed, and many have significant influence on atmospheric chemistry at the …


Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad Jul 1997

Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad

Chemistry & Biochemistry Theses & Dissertations

Bisulfite is commonly used to dechlorinate chlorinated municipal wastewater. However, several studies suggest that bisulfite is not effective in dechlorinating N-chlorinated amino components of wastewater. The purpose of this study was to investigate the effectiveness of an alternate dechlorinating agent, caroate (peroxysulfate), and to compare its rate of dechlorination of three different types of chloramines with that of bisulfite.

Four N-chlorinated amino compounds were investigated: N-chlorodiethylamine, chloroalanylphenylalanine, N-chloroglycylphenylalanine, and N-[2-(N'-chloroimino)­ propanoyl]phenylalanine. These compounds were selected from different families of chloramines to study the effect of structure on dechlorination by both caroate and bisulfite. At pH …


Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike Jul 1997

Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike

Chemistry & Biochemistry Theses & Dissertations

We investigated the separation of selenoprotein P and extracellular (serum) glutathione peroxidase using a concanavalin A affinity column. We were able to show that the method does not adequately separate serum glutathione peroxidase from selenoprotein P because human glutathione peroxidase binds strongly to the column. We also found that albumin can interfere with measurement serum of glutathione peroxidase activity when hydrogen peroxide is used as the substrate. When t-butyl hydroperoxide was used as the substrate, less than 10% of the measured activity was due to the presence of albumin. We also found that the pH of the elution buffer plays …


Grand Canonical Monte Carlo And Modified Singlet Integral Equations For The Density Profile Of A Yukawa Fluid Near A Planar Wall, Douglas Henderson, Wilmer Olivares-Rivas, Leo Degreve, Jacqueline Quintana May 1997

Grand Canonical Monte Carlo And Modified Singlet Integral Equations For The Density Profile Of A Yukawa Fluid Near A Planar Wall, Douglas Henderson, Wilmer Olivares-Rivas, Leo Degreve, Jacqueline Quintana

Faculty Publications

Results for the density profile for Yukawa molecules near a hard wall and an exponential attractive wall are presented for Grand Canonical Monte Carlo (GCMC) simulations, for the singlet hypernetted chain (HNC) integral equation and for a modified version of the Lovett–Mou–Buff–Wertheim (LMBW-1) which uses the exact contact value theorem. The results of the standard singlet HNC are quite poor. If the LMBW equation is modified (but still using the bulk direct correlation function) the results at high temperature become reasonable. However, the results at low temperatures, close to the bulk coexistence curve, are only a partial improvement. The contact …