Chemistry Commons^™

The Release Of Calcium In Bacillus Anthracis Pathogenicity, Natiera Magnuson, Manomita Patra, Maria Elena Reynaga, Ernesto Abel-Santos

McNair Poster Presentations

Bacillus anthracis spores form in response to starvation and can withstand extremes of heat, radiation, and chemical toxins, making B. anthracis spores ideal vehicles for infections.1 The resistance and dormancy of bacterial spores are dependent on a largely dehydrated core.2 The spore core is not only devoid of water, but contains between 0.8 to 1M calcium complexed with 2,6-pyridinedicarboxylic acid (dipicolinic acid, DPA). The DPA-calcium complex (CaDPA) helps protect DNA, RNA, and the metabolic enzymes needed for the establishment of a vegetative cell cytoplasm.3 An anthrax infection starts with the germination of B. anthracis spores in a macrophage.4 The germinated …

Chemical And Electronic Structure Of Surfaces And Interfaces In Compound Semiconductors, Sujitra Pookpanratana

UNLV Theses, Dissertations, Professional Papers, and Capstones

The interface formation between two different materials is important in applications for optoelectronic devices. Often, the success or performance of these devices is dependent on the formation of these heterojunctions. In this work, the surface and interfaces in such materials for optoelectronic devices are investigated by a suite of X-ray analytical techniques including X-ray photoelectron (XPS), X-ray excited Auger electron (XAES), and X-ray emission (XES) spectroscopies to provide novel insight.

For the group III-nitrides (e.g., AlxGa1-xN) used in many light emitting devices, a significant challenge exists to form an Ohmic contact. The electron affinities and band gaps of GaN and …

Speciation And Spectroscopy Of The Uranyl And Tetravalent Plutonium Nitrate Systems: Fundamental Studies And Applications To Used Fuel Reprocessing, Nicholas A. Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation explores the use of UV-Visible spectroscopy and Time Resolved Laser Induced Fluorescence spectroscopy as near real time process monitors of uranium and plutonium concentrations in aqueous reprocessing trains. The molar absorptivities and linear ranges of these metals were investigated under total nitrate and acid concentrations similar to those found in current reprocessing systems. Concurrent to this, a new multiple wavelength monitor was derived that is capable of determining the total nitrate concentration spectroscopically. This method uses the uranium absorbance spectrum to calculate the nitrate concentration in solution. When used as part of an Advanced Safeguard suite, this technique …

Jahn-Teller Coupling And Fragmentation After Core-Shell Excitation Ini Cf4 Investigated By Partial-Ion-Yield Spectroscopy, Renaud Guillemin, Wayne C. Stolte, Maria Novella Piancastelli, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We investigate fragmentation processes induced by core-level photoexcitation in CF4 at both the carbon and fluorine K edges by means of partial-ion-yield spectroscopy. The molecule CF₄ is a textbook example of systems in which Jahn-Teller coupling strongly manifests itself in the photoabsorption spectrum. Spectral features related to Jahn-Teller and quasi-Jahn-Teller splitting are observed, and important differences in the fragmentation pathways are revealed depending on the symmetries of the core-excited states. We interpret these experimental observations on the grounds of symmetry lowering from the Td to the C3v point group as well as preferential orientation with respect …

Hrc Enews — 2010 Fall, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.

Nvrec Subtask 1.1: Pre-Treatment Of Lignocellulosic Biomass, Amber Broch, Kent Hoekman, Larry Felix, Rick Purcell, Curt Robbins, Wei Yan

Nevada Renewable Energy Consortium Meeting

The second annual Nevada Renewable Energy Consortium meeting took place at UNLV on August 20. The meeting focused on the current three NVREC program areas: Solar, Biomass and Geothermal. Presentations were made by participating entities and a poster session followed.

Nvrec Subtask 1.2: Thermal Treatment Of Biomass, Curtis Robbins, Eric Ceniceros, Kent Hoekman, Richard Jasoni

Nevada Renewable Energy Consortium Meeting

The second annual Nevada Renewable Energy Consortium meeting took place at UNLV on August 20. The meeting focused on the current three NVREC program areas: Solar, Biomass and Geothermal. Presentations were made by participating entities and a poster session followed.

Full Multiple Scattering Analysis Of Xanes At The Cd L 3- And O K- Edges In Cdo Films Combined With A Soft-X-Ray Emission Investigation, I. N. Demchenko, J. D. Denlinger, M. Chernyshova, K. M. Yu, D. T. Speaks, P. Olalde-Velasco, Oliver Hemmers, W. Walukiewicz, A. Derkachova, K. Lawniczak-Jablonska

Environmental Studies Faculty Publications

X-ray absorption near edge structure (XANES) at the cadmium L3 and oxygen K edges for CdO thin films grown by pulsed laser deposition method, is interpreted within the real-space multiple scattering formalism, FEFF code. The features in the experimental spectra are well reproduced by calculations for a cluster of about six and ten coordination shells around the absorber for L3 edge of Cd and K edge of O, respectively. The calculated projected electronic density of states is found to be in good agreement with unoccupied electronic states in experimental data and allows to conclude that the orbital character of the …

Y-Aminobutyric Acid Inhibits Synergistic Interleukin-6 Release And Increases Intracellular Cytokine Content In C6 Astrocytoma Cells In Vitro, Daniella Sandoval, Becky M. Hess, Bryan L. Spangelo

Undergraduate Research Opportunities Program (UROP)

Alzheimer’s disease (AD) is a neurodegenerative disorder that is characterized by memory loss and is the most common cause of dementia. It is has been hypothesized that pro-inflammatory cytokines induce the inflammation that is believed to be the cause of the neuronal death that is associated with AD. γ-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the Central Nervous System possessing membrane hyperpolarization or depolarization activities. A decline in GABA may enhance cytokine release in Alzheimer’s disease resulting in neuroinflammation. Therefore, we investigated the GABA-mediated suppression of the synergistic release of interleukin-6 (IL-6) induced by interleukin 1- (IL-1) and …

Nitrogen Cycle In Great Basin Hot Springs, Tara A. Edwards, Paula Matheus-Carnevali, Ryan Wahrenbrock, Jeremy A. Dodsworth, Brain P. Hedlund

Undergraduate Research Opportunities Program (UROP)

Nitrification and denitrification are two important steps in the nitrogen cycle . Nitrification, a two step process, leads to the production of NO3-, (Fig. 1). In the first step, ammonia oxidation, NH3 is oxidized to NO2-, and in the second step, nitrite oxidation, NO2- is oxidized to NO3-. Until recently, very little was know about nitrification in high temperature environments. However, in 2008 a thermophilic archaeon, named “Candidatus Nitrosocaldus yellowstonii”, was shown to mediate ammonia oxidation up to 74°C. More recently , NO2- oxidizing bacteria were discovered that are active in temperatures up to 48°C(4). While NH3 oxidation is generally …

Synthesis Of Novel Aromatic Quinols For Colon And Renal Cancers, Bradley J. Davey, Tae Soo Jo, Pradip K. Bhowmik

Undergraduate Research Opportunities Program (UROP)

Colon Cancer: The third most common cancer in USA. More than 1 million Americans currently living with colon cancer. 148,810 new cases expected in 2010. 50,000 deaths annually.

Renal Cancer: Approximately 58,000 people diagnosed in USA annually. Seventh most common cancer and tenth most common cause of cancer related death in men.

Aromatic quinols have demonstrated in vitro antitumor activity. Three heteroaromatic quinols show antitumor activity.

Synthesis Of Bis-Styrylbenzene Derivatives Via Wittig-Horner Reaction, Joseph K. Wray, Tae Soo Jo, Pradip K. Browmik

Undergraduate Research Opportunities Program (UROP)

Alzheimer’s Disease is now one of the most common diseases affecting the elderly population. Recently, bis-styrylbenzene derivatives have been shown to reduce the formation of Beta-amyloid plaques in the brain which are profoundly correlated with this disease. Finding new biologically active compounds which can reduce or prevent Alzheimer’s Disease has drawn much attention over the past few decades. Georg Wittig, Nobel Prize Winner in Chemistry, 1979.

Undergraduate Research Opportunities Program 2010, University Of Nevada, Las Vegas

Undergraduate Research Opportunities Program (UROP)

The Undergraduate Research Opportunities Program (UROP) cultivates and supports research partnerships and invites undergraduates to work as the junior colleagues of faculty. The program offers the opportunity to work on cutting edge research—whether you join established research projects or pursue your own ideas. As participants, undergraduates engage in each phase of standard research activity: developing research plans, writing proposals, conducting research, analyzing data. and presenting research results in oral and written form. The projects take place over the summer, and research can be done in any academic department or interdisciplinary laboratory. Projects can last for an entire semester, and many …

Vibrational Spectroscopic Study Of The 1,3,5,7-Cyclooctatetraene At High Static Pressures, Edward Romano

UNLV Theses, Dissertations, Professional Papers, and Capstones

1,3,5,7-cyclooctatetraene (COT) is a single-ringed hydrocarbon that has not been studied extensively under high static pressures. It was the intent of this study to reveal its high-pressure behavior through its vibrational spectra. To this end, its infrared spectra as a function of pressure were collected at the National Synchrotron Light Source (NSLS) U2A beamline, as well as its Raman spectra over pressure using a micro-Raman spectrometer.

The spectra show the typical stiffening of force constants with increasing pressure for most peaks, particularly those which would theoretically exhibit a mode-softening behavior under hypotheses of molecular planarization and aromatization. Additionally, the data …

Synthesis And Characterization Of Photoactive Amorphous Molecular And Polymeric Pyridinium Materials, Alexi Kamenov Nedeltchev

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pyridinium materials both molecular and polymeric are interesting class of multifunctional electrolytes and polyelectrolytes, which exhibit liquid-crystalline and light-emitting properties. Moreover, their properties could be easily tuned simply by modifying the chemical structures of counterions.

In this dissertation, we described the preparation and analysis of new ionic molecular materials based on bis(pyridinium salt)s and a new class of poly(pyridinium salt)s with various heterocyclic moieties in their backbones with various organic counterions. They were prepared by either ring-transmutation reaction or by metathesis reaction. Their chemical structures were confirmed by FTIR, 1H and 13C NMR spectroscopy and elemental analysis. They had excellent …

Hrc Enews — 2010 Summer, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.

Preparation And Characterization Of Extraction Chromatography Resins Using N-Donor Extractants For Trivalent Actinide And Lanthanide Separations, Christopher L. Klug

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actinide and lanthanide elements exist in the geosphere and biosphere due to both natural abundances and anthropogenic activities. The investigation of the presence and transport of actinides through the environment is of great scientific interest. In order to prepare environmental samples for precise measurements, the individual actinides must be separated from the chemically similar lanthanides, and from neighboring actinides. Existing extraction chromatography resins are either poorly suited for this separation, have bleeding problems, are not reusable, or fail the CHON principle. In an effort to resolve these issues, malonamides and N-donor extractants from the BTP and BTBP classes of solvent …

Antimicrobial Activity Of D-Lenolate®, Andy Phui

UNLV Theses, Dissertations, Professional Papers, and Capstones

Olive trees are one of the most important fruit trees in the Mediterranean. Although not validated by research, olive leaves are traditionally believed to fight off fever and infections. It has been shown that olive leaf extracts possess antimicrobial activity. Olive leaf extracts contain polyphenols. One of the major phenolic compounds is oleuropein. Oleuropein and other polyphenols have been shown to exhibit antimicrobial activity. East Park Research (EPR) developed an extraction process that they claim does not alter the chemical composition of the olive leaves. The extract is known by the commercial name d-lenolate®. Studies have provided evidence that d-lenolate®, …

Bacillus Cereus And Bacillus Anthracis Germination Kinetics: A Michaelis-Menten Approach, Helen Luu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bacillus species are rod-shaped, gram-positive bacteria that are capable of producing endospores. In this dormant stage, the endospores can persist in hostile physical and chemical environments. Once conditions become favorable, the spores germinate into actively dividing cells, vegetative cells. Germination is a crucial step for the pathogenicity of the Bacilli in affecting a host organism.

Our study applies mathematical approaches to spore germination to determine whether the binding of one germinant will affect the binding of another germinant. We pursued this approach with two different species, B. cereus and B. anthracis, both pathogenic organisms. B. cereus is a widely known …

Characterization Of Plutonium Particles Originating From The Bomarc Accident -1960, Richard Charles Gostic

UNLV Theses, Dissertations, Professional Papers, and Capstones

Within the U.S. arsenal, 32 accidents with nuclear weapons were reported between 1950 and 1980. One of these accidents occurred at McGuire AFB in 1960. A BOMARC missile armed with a nuclear warhead caught on fire and as a result the warhead was destroyed. Sub-millimeter particles consisting of weapons grade plutonium (WGPu) produced by this accident were distributed around the site and remained in the environment for 47 years. Soil cores known to contain WGPu particles produced by this accident were obtained. The particles were localized and removed from the soil with the aid of high resolution computed tomography. The …

Hrc Enews — 2010 Spring, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, a "new faces" listing for new staff, affiliates, and researchers, and an "of interest" section.

Sulfur K-Edge Photo-Fragmentation Of Ethylene Sulfide, Wayne C. Stolte, Gunnar Ohrwall

Chemistry and Biochemistry Faculty Research

We have investigated the photofragmentation properties of the three-membered ring heterocyclic molecule ethylene sulfide or thiirane, C₂H₄S, by time-of-flight mass spectroscopy. Positive ions have been collected as a function of photon energy around the S K ionization threshold. Branching ratios were derived for all detected ions, which are informative of the decay dynamics and photofragmentation patterns of the core-excited species. We present a new assignment of the spectral features around the S K-edge.

Hrc Enews — 2010 Winter, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, a "new faces" listing for new staff, affiliates, and researchers, and an "on the move" section listing new developments.

Manganese Oxide Mineral Phases Produced At Room Temperature Under Acidic Conditions Investigated With Xrd, Tem, Sem, Eds, And Bet, Nancy R. Birkner

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis concerns characterization of synthetic manganese oxides belonging to mineral phases known as Birnessite and Cryptomelane. Presented here are the results of an experiment designed to examine the influence of sodium, potassium, chloride, and sulfate ions on the reduction of potassium permanganate under acidic conditions at room temperature to produce Birnessite and Cryptomelane. The experiments used KMnO4 as the source of Mn and the resulting Birnessite and Cryptomelane precipitates were washed with 18 Mn/cm NANOpure water at the end of syntheses. Several state-of-the-art solid state techniques were used to characterize the Mn-based oxide mineral phases. Based on the literature …

Fragmentation Properties Of Three-Membered Ring Heterocyclic Molecules By Partial Ion Yield Spectroscopy: C2h4o And C2h4s, Wayne C. Stolte, I. Dumitriu, S-W Yu, Gunnar Ohrwall, Maria Novella Piancastelli, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We investigated the photofragmentation properties of two three-membered ring heterocyclic molecules, C₂H₄O and C₂H₄S, by total and partial ion yield spectroscopy. Positive and negative ions have been collected as a function of photon energy around the C 1s and O 1s ionization thresholds in C₂H₄O, and around the S 2p and C 1s thresholds in C₂H₄S. We underline similarities and differences between these two analogous systems. We present a new assignment of the spectral features around the C K-edge and the sulfur L_{2 …}

Unlv Magazine, Matthew K. Jacobsen, Holly Ivy De Vore, Lisa Arth, Cate Weeks, Greg Lacour, Tony Allen, Afsha Bawany, Barbara Cloud, Gian Galassi, Phil Hagen, Karyn S. Hollingsworth, Michelle Mouton, Erin O'Donnell

UNLV Magazine

No abstract provided.

Experimental And Theoretical Investigation Of Molecular Field Effects By Polarization-Resolved Resonant Inelastic X-Ray Scattering, Stephane Carniato, Renaud Guillemin, Wayne C. Stolte, Loic Journel, Richard Taieb, Dennis W. Lindle, Marc Simon

Chemistry and Biochemistry Faculty Research

We present a combined theoretical and experimental study of molecular field effects on molecular core levels. Polarization-dependent resonant inelastic x-ray scattering is observed experimentally after resonant K-shell excitation of CF₃Cl and HCl. We explain the linear dichroism observed in spin-orbit level intensities as due to molecular field effects, including singlet-triplet exchange, and interpret this behavior in terms of population differences in the 2p_x,y,z inner-shell orbitals. We investigate theoretically the different factors that can affect the electronic populations and the dynamical R dependence of the spin-orbit ratio. Finally, the results obtained are used to interpret the L-shell …

Mitigating Co2 Production In Coal-To-Liquids Process, Robert Walty

UNLV Renewable Energy Symposium

The 3rd Annual Renewable Energy Symposium took place on the UNLV campus August 11 & 12. The event focused on renewable energy production in Nevada, the US Southwest, and renewable research projects nationwide. The event was a great success with over 200 individuals in attendance.

Hydrogen In Non-Crystalline Materials: From Solar Cells To Hydrogen Storage, Anatolii Shkrebtii

UNLV Renewable Energy Symposium

The 3rd Annual Renewable Energy Symposium took place on the UNLV campus August 11 & 12. The event focused on renewable energy production in Nevada, the US Southwest, and renewable research projects nationwide. The event was a great success with over 200 individuals in attendance.

Hydrogen R&D At Sandia National Labs, Lennie Klebanoff

UNLV Renewable Energy Symposium

The 3rd Annual Renewable Energy Symposium took place on the UNLV campus August 11 & 12. The event focused on renewable energy production in Nevada, the US Southwest, and renewable research projects nationwide. The event was a great success with over 200 individuals in attendance.