Chemistry Commons^™

Comparative Biochemical Analysis Of Uhrf Proteins Reveals Molecular Mechanisms That Uncouple Uhrf2 From Dna Methylation Maintenance, Robert M. Vaughan, Bradley M. Dickson, Evan M. Cornett, Joseph S. Harrison, Brian Kuhlman, Scott B. Rothbart

College of the Pacific Faculty Articles

UHRF1 is a histone- and DNA-binding E3 ubiquitin ligase that functions with DNMT1 to maintain mammalian DNA methylation. UHRF1 facilitates DNMT1 recruitment to replicating chromatin through a coordinated mechanism involving histone and DNA recognition and histone ubiquitination. UHRF2 shares structural homology with UHRF1, but surprisingly lacks functional redundancy to facilitate DNA methylation maintenance. Molecular mechanisms uncoupling UHRF2 from DNA methylation maintenance are poorly defined. Through comprehensive and comparative biochemical analysis of recombinant human UHRF1 and UHRF2 reader and writer activities, we reveal conserved modes of histone PTM recognition but divergent DNA binding properties. While UHRF1 and UHRF2 diverge in their …

Development Of Lc-Ms For The Identification And Characterization Of Non-Adjacent Dna Photoproduct Formation In G-Quadruplex Forming Sequences, Claudia Posadas

Arts & Sciences Graduate Student Theses and Dissertations

Ultraviolet light is well known to induce cyclobutane pyrimidine dimers (CPD) and pyrimidine (6–4) pyrimidone photoproducts in duplex DNA, which interfere with DNA replication and transcription. Recently, a new class of DNA photoproducts known as anti cyclobutanepyrimidine dimers have been discovered, which form in G-quadruplex forming sequences in solution. G-quadruplex structures have been proposed to form in human DNA telomeres and certain promoters in vivo but evidence for their existence has been lacking. Since anti-cyclobutante pyrimidine dimers have been shown to form in G-quadruplex forming sequences, their formation in irradiated human cells could be used to confirm the existence …

Concentration Of Atmospheric Ammonia From Kenyon College Monitoring Station, Vivian Ezeh, David Heithaus, Simon Garcia, Matthew F. Rouhier

Data Sets

Kenyon College is hosting an ammonia (NH3) monitoring station as part of the National Atmospheric Deposition Program (NADP). The Kenyon College (OH32) site is one of six locations around the state of Ohio.

Use Of Biometrics To Determine Biochemistry Knowledge Level Differences In Reading And Processing Metabolic Pathways, Kim Kammerdiener

Master of Science in Chemical Sciences Theses

The areas of chemistry and biochemistry commonly use external representations to enhance learning for students. The use of schematics and representations for illustrating metabolic pathways is a familiar image in most biochemistry textbooks. These external representations can be the key to student understanding. To date, there has not been any previous research specifically focused on the areas of interest that are predominant for an individual viewing a metabolic pathway commonly found in a biochemistry textbook. Therefore, this thesis study set out to 1) investigate what individuals look at in a metabolic pathway based on their level of expertise in metabolism …

Salt-Assisted Ultrasonic Disaggregation Of Nanodiamond, Vadym Mochalin, Kostiantyn Turcheniuk, Caleb Trecazzi

Chemistry Faculty Research & Creative Works

Methods for disaggregating nanodiamond clusters, for example, by using ultrasound to break apart nanodiamond aggregates in a sodium chloride aqueous slurry. Compositions, such as aqueous nanodiamond dispersions and dry particulate compositions that may be produced using these methods.

Spectroscopy And Formation Of Lanthanum-Hydrocarbon Radicals Formed By Association And Carbon-Carbon Bond Cleavage Of Isoprene, Wenjin Cao, Dilkrushi Hewage, Dong-Sheng Yang

Chemistry Faculty Publications

La atom reaction with isoprene is carried out in a laser-vaporization molecular beam source. The reaction yields an adduct as the major product and C—C cleaved and dehydrogenated species as the minor ones. La(C₅H₈), La(C₂H₂), and La(C₃H₄) are characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of all three species exhibit a strong origin band and several weak vibronic bands corresponding to La-ligand stretch and ligand-based bend excitations. La(C₅H₈) is a five-membered metallacycle, whereas La(C₂H_{2 …}

Treatment Of Mci And Alzheimer's Disease, Mark A. Lovell, Bert C. Lynn

Chemistry Faculty Patents

The present invention provides, among other things, therapeutic compositions and methods that can effectively treat, slow or prevent a neurological disease (e.g., a neurodegenerative disease, e.g., mild cognitive impairment (MCI) or Alzheimer's disease (AD)), in particular, based on therapeutically effective amount of nifedipine, oxidized or nitroso nifedipine derivatives, lactam (e.g., a compound of formula (Ic) or (Ic-i), e.g., NFD-L1), thyroxine (T4), triiodothyronine (T3) and combinations thereof.

E-Cigarettes Can Emit Formaldehyde At High Levels Under Conditions That Have Been Reported To Be Non-Averse To Users, James C. Salamanca, Jiries Meehan-Attrash, Shawna Vreeke, Jorge O. Escobedo, David H. Peyton, Robert M. Strongin

Chemistry Faculty Publications and Presentations

E-cigarette aerosol emission studies typically focus on benchmarking toxicant levels versus those of cigarettes. However, such studies do not fully account for the distinct chemical makeup of e-liquids and their unique properties. These approaches often conclude that there are fewer and lower levels of toxins produced by e-cigarettes than by cigarettes. In 2015, we reported the discovery of new hemiacetals derived from the reaction of formaldehyde and the e-liquid solvents. The main finding was that they constituted a significant proportion of potentially undetected formaldehyde. Moreover, unlike gaseous formaldehyde, the hemiacetals reside in the aerosol particulate phase, and thus are capable …

Assessment Of Energetic Heterogeneity Of Reversed-Phase Surfaces Using Excess Adsorption Isotherms For Hplc Column Characterization, Leih-Shan Yeung

Seton Hall University Dissertations and Theses (ETDs)

This research is to explore a more general column categorization method using the test attributes in alignment with the common mobile phase components. As we know, the primary driving force for solute retention on a reversed-phase surface is hydrophobic interaction, thus hydrophobicity of the column will directly affect the analyte retention. This research describes a method to determine the column hydrophobicity by the ratio of adsorbed acetonitrile and methanol to water on the column surface using excess adsorption isotherm estimation. An excess adsorption isotherm for a binary mobile phase system represents a competitive interaction of both solvent components with the …

Characterization Of Protease-Activated Receptor (Par) Ligands: Parmodulins Are Reversible Allosteric Inhibitors Of Par1-Driven Calcium Mobilization In Endothelial Cells, Disha M. Gandhi, Mark W. Majewski, Ricardo Rosas Jr., Kaitlin Kentala, Trevor J. Foster, Eric Greve, Chris Dockendorff

Chemistry Faculty Research and Publications

Several classes of ligands for Protease-Activated Receptors (PARs) have shown impressive anti-inflammatory and cytoprotective activities, including PAR2 antagonists and the PAR1-targeting parmodulins. In order to support medicinal chemistry studies with hundreds of compounds and to perform detailed mode-of-action studies, it became important to develop a reliable PAR assay that is operational with endothelial cells, which mediate the cytoprotective effects of interest. We report a detailed protocol for an intracellular calcium mobilization assay with adherent endothelial cells in multiwell plates that was used to study a number of known and new PAR1 and PAR2 ligands, including an alkynylated version of the …

Mass Spectrometry-Based Strategies For Protein Characterization: Amyloid Formation, Protein-Ligand Interactions And Structures Of Membrane Proteins In Live Cells, Ke Li

Arts & Sciences Graduate Student Theses and Dissertations

Mass spectrometry (MS)-based protein footprinting characterizes protein structure and protein-ligand interactions by interrogating protein solvent-accessible surfaces by using chemical reagents as probes. The method is highly applicable to protein or protein-ligand complexes that are difficult to study by conventional means such as X-ray crystallography and nuclear magnetic resonance. In this dissertation, we describe the development and application of MS-based protein footprinting from three perspectives, including I) protein aggregation and amyloid formation (Chapter 2-3), II) protein-ligand interactions (Chapter 4-5), and III) in-cellulo structures and dynamic motion of membrane proteins (Chapter 6). Fast Photochemical Oxidation of Proteins (FPOP) is the main methodology …

Determination Of Anthropogenic Radionuclides In Ocean Water Using Extraction Chromatography, Jaimie Daum

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the aftermath of the reactor accident in Fukushima, it has become obvious that there is a severe lack in methods that would allow for the rapid determination of anthropogenic radionuclides in ocean water. Current radioanalytical techniques for the determination of radionuclides in natural waters have a number of disadvantages including the fact that they are time consuming, generate a substantial amount of waste, and are typically multi-step processes. Additionally, the elevated amount of dissolved ions in ocean water imparts a complex matrix that can interfere with the rapid separation and determination of anthropogenic radionuclides. Therefore, due to the size, …

Breaking The Language Barrier: Equitable Assessment In General Chemistry, Eshani Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Because language provides the framework through which knowledge is constructed, it is crucial to consider the ways in which students with limited English proficiencies are able to express their understanding. English language learners (ELLs) make up a significant portion of the student body in the education system and represent many ethnic and racial minorities in STEM (Science, Technology, Engineering & Mathematics) fields (Burke & Mattis, 2007). Despite the national push to build a more diversified, STEM-ready workforce, there is little research that considers the way ELLs are assessed in STEM courses at the postsecondary level. Literature reports that science tests …

Rapid Methods For Actinide And Strontium-89,90 Determination In Urban Matrices, Sherrod Maxwell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rapid radiochemical methods are needed to provide fast, reliable analytical measurements on a variety of different sample matrices in the case of a radiological event to protect the public, mitigate dose and protect the environment. If a radiological dispersive device (RDD), an Improvised Nuclear Device (IND) or a nuclear accident occurs, there will be an urgent need for quick analyses of urban matrices materials to support decision-making, dose mitigation and environmental clean-up. Since an incident involving a RDD or IND will likely occur in an urban or metropolitan area, it is very important to employ swift, robust analytical methods that …

Development Of Chemical Separation Methods Using Transition Metals For Nuclear Forensic And Medicinal Applications, Lucas Peter Boron-Brenner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Insufficient data exists on the effects of prompt fast neutron activation on metals found commonly in nuclear devices and the urban environment. Different metals such as Ti, Au, Fe, and Cu were activated using the Flattop Criticality Benchmark at the Device Assembly Facility on the Nevada Test Site using a known neutron spectrum and flux to determine a baseline cross section value. Cross section information gathered from these neutron activation measurements could provide information that helps government and law enforcement agencies to correctly trace the origin of a nuclear device’s fuel or component features.

Based on activation products produced in …

Separation Of Neighboring Trivalent Lanthanides For Neutron Capture Cross Section Measurements, Balazs Jozsef Bene

UNLV Theses, Dissertations, Professional Papers, and Capstones

The determination of the low-energy neutron capture cross-section of 171Tm with greater accuracy is important for both astrophysics and Stockpile Stewardship. Thulium-171 is a branching point in the s-process of stellar nucleosynthesis. Branching point nuclei, with half-lives in the order of 1 – 100 years are places where neutron capture and beta decay competes. This isotope is also the second order (n, γ) reaction product of 169Tm, which was used as a radiochemical detector in nuclear weapon experiments. It was placed at strategic locations in nuclear devices. Following the test, samples were analyzed in the collected samples for products of …

Use Of Sodium Bismuthate Chromatography For Separation Of Americium From Curium And Other Elements In Spent Nuclear Fuel, Jason Michael Richards

UNLV Theses, Dissertations, Professional Papers, and Capstones

A novel method for partitioning americium from curium has been developed using sodium bismuthate as both an oxidant and a separation medium. The presence of americium and curium in nuclear waste increases the heat load in geological repositories and leads to larger waste volumes. These elements are also the source of most of the long-term radiotoxicity of the waste. However, the heat load and long-term radiotoxicity contribution from americium is much greater than that from curium. The contribution of curium to the heat load and radiotoxicity of the waste is significant on the same time scale as longer-lived fission products …

Solvent Extraction And Extraction Chromatography Of Homologs And Pseudohomologs Of Rutherfordium Using Teha And Tehp, Jeffrey Rolfes

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studies of the chemical properties of the heaviest elements have always been difficult due to the short half-lives and low cross sections involved. To solve this problem, atom-at-a-time methods are necessary to determine the properties of these short-lived isotopes. Extremely fast kinetics for the chemical reactions studied (on the same order as the nuclide’s half-life) are required, and the system should have the potential for automation. Solvent extraction, with its selectivity and quick kinetics, has historically been used for these investigations into characteristics of super heavy elements. Another technique, extraction chromatography, offers potentially a way of investigating rutherfordium’s properties, without …

Applications Of Nanoporous Materials In Gas Separation And Storage, Amit Sharma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Past decades in the field of gas separation and storage utilized the concepts of both cryogenic distillation and non-cryogenic methods such as high-pressure cylinders but few concerns – efficiency, energy intensiveness, cost associated, risk of failure always existed. Recent advances in the field focuses on using porous materials especially nanoporous materials. Nanoporous materials, due to their well-defined structure, range of pore diameters, and striking surface chemistry hold over traditional porous materials for gas separation and storage. With pore diameter less than 2 nm and abundance of energetically favorable sites (such as unsaturated metal sites, channels, cages, cavities etc.), these materials …

Effect Of Dna Sequence Context, Dna Structure, And Excitation Method On Cyclobutane Pyrimidine Dimer Formation, Chen Lu

Arts & Sciences Graduate Student Theses and Dissertations

The cis-syn cyclobutane pyrimdine dimer (CPD) is the major photoproduct resulting from UV irradiation of duplex DNA that results in C to T mutations found in human skin. CPDs with the anti stereochemistry were recently discovered to be formed in human telomeric DNA that adopts a quadruplex structure in vitro and may also play a role in the effects of sunlight in vivo. In this thesis, the effect of telomeric DNA structure on the formation of the anti-CPDs is investigated, as well as the effect of sequence context on cis-syn CPD formation which could help explain the origin of DNA …

Characterization Of A Catalyst-Based Conversion Technique To Measure Total Particulate Nitrogen And Organic Carbon And Comparison To A Particle Mass Measurement Instrument, Chelsea E. Stockwell, Agnieszka Kupc, Bartlomiej Witkowski, Ranajit K. Talukdar, Yong Liu, Vanessa Selimovic, Kyle J. Zarzana, Kanako Sekimoto, Carsten Warneke, Rebecca A. Washenfelder, Robert J. Yokelson, Ann M. Middlebrook, James M. Roberts

Chemistry and Biochemistry Faculty Publications

The chemical composition of aerosol particles is a key aspect in determining their impact on the environment. For example, nitrogen-containing particles impact atmospheric chemistry, air quality, and ecological N deposition. Instruments that measure total reactive nitrogen (Nr Combining double low line all nitrogen compounds except for N2 and N2O) focus on gas-phase nitrogen and very few studies directly discuss the instrument capacity to measure the mass of Nr-containing particles. Here, we investigate the mass quantification of particle-bound nitrogen using a custom Nr system that involves total conversion to nitric oxide (NO) across platinum and molybdenum catalysts followed by NOĝ'O3 chemiluminescence …

Biochar From Waste Banana Peels As Growth Promoter For Holy Basil (Ocimum Tenuiflorum) And Chili Pepper (Capsicum Annuum), Regina C. So, N Tan

Chemistry Faculty Publications

Biochars are porous materials prepared by combustion of biomass under the presence of low oxygen levels. Its application as soil fertilizer has been shown to have positive effects on the plants by increasing the fertility and raising the soil pH, increasing nutrient cycling and moisture holding capacity, improving cation exchange capacity, and reducing the amount of pesticides and nutrients leaching to the surface and ground water (Laird 2008, Speratti 2017). In this study, waste banana peels of the Lakatan variety (Musa x paradisiaca) were pyrolized at temperatures 300, 400, 500 and 700 °C, the resulting basic char were obtained at …

Flame Retardancy Of Ferrocene Incorporated Epoxide, Sultan Alanazi

Electronic Theses & Dissertations

Epoxy resins are thermosetting resins that are used in a variety of applications such as electrical and electronic devices. However, epoxy resins can be inherently flammable. To circumvent this problem, epoxy resins were prepared by incorporating ferrocene carboxylic acid into the epoxy prior to thermal setting, as a flame retardant. Ferrocene carboxylic acid was prepared by condensing o-chlorobenzoyl chloride with ferrocene followed by hydrolysis. The synthesized ferrocene carboxylic acid was characterized by ¹H-NMR spectroscopy, ¹³C-NMR spectroscopy, and FT-IR spectroscopy. Epoxy films were then prepared by reacting ferrocene carboxylic acid (10, 15, and 20% by wt) with bisphenol A …

Detection Of Salen-Type Tracers For Subterranean Fluid Flow Monitoring Using Surface-Enhanced Raman Spectroscopy, Jenny C. Sanchez

Chemistry and Chemical Biology ETDs

A series of hydrocarbon and aqueous soluble salen-type ligands have been synthesized and characterized by electronic and vibrational spectroscopy. Aqueous soluble salen-type ligands were complexed to a metal and investigated as potential underground fluid flow tracers using Surface-Enhanced Raman Spectroscopy (SERS) as the analytical technique. Vibrational spectra obtained from SERS was shown to have enhanced the spectral signal for these complexes in low concentrations though did not show significant differences between the free ligands and their metal complexes. This research has shown that, with some structural modifications, salen-type ligands can be effective candidates as subterranean fluid flow tracers when SERS …

Copper-Catalyzed Direct And Tandem Couplings, And Mechanistic Studies, Surendra Thapa

Chemistry and Chemical Biology ETDs

Cross-coupling reactions are exceptionally powerful tools to construct carbon-carbon (C-C) bonds. These reactions are widely used to synthesize natural products, polymers, agrochemical, organic materials and pharmaceutical compounds. However, these reactions are typically catalyzed by Palladium. Although these reactions are widely utilized and well developed, the use of noble metals like Pd raises a question about its long-term sustainability. We believe copper can be one of the best alternatives to palladium as it is more abundant, less expensive and less toxic. In addition, Pd-catalyzed transformations usually suffer from β-hydride elimination to afford undesired olefin and rearranged products, when it comes …

A Facile Method To Synthesize Bi-Functional Nanostructured Nickel Compounds For Energy Storage And Water Splitting Applications, Nawaf Albeladi

Electronic Theses & Dissertations

In recent years, the increasing demands for clean, efficient, and renewable energy have triggered researchers to increase their effort to develop multi-functional materials for energy applications. Supercapacitors, among the comparative energy storage devices, have attracted considerable attention due to their high energy storage capacity, fast charge-discharge capability, long cycle life, and high power density. Transition metal oxides and sulfides are being used as materials for supercapacitor applications due to their excellent conductivity, high electrochemical properties, and large theoretical energy storage capacitance. On the other hand, among the numerous energy techniques, water splitting has become one of the most important technologies …

A Detailed Study Of Novel High-Performance Bromine And Phosphorus Based Reactive Flame Retardants In High-Quality Bio-Polyol Based Rigid Polyurethane Foams, Sanket Bhoyate

Electronic Theses & Dissertations

Structural fire is one of the most catastrophic issues related to human safety observed from reports of National Fire Protection Association of United States in past years. Polyurethanes are one of the important structural material used as thermal insulation in housing. They are also used in automotive, construction, medical, packaging, furniture, thermal, electrical, and vibration insulation. Considering this, we have synthesized bio-based polyurethane foams using limonene-based polyol, isocyanates, and other compounds. Flame retardancy was imparted using reactive flame retardant polyols. Firstly, flame retardancy test was performed on the foams using two novel aliphatic and two novel aromatic bromine-based synthesized reactive …

Nanocomposites Of Polypyrrole And Cobalt Oxide As Efficient And Stable Multifunctional Materials For Supercapacitors And Overall Water Splitting, Ahlam Alghamdi

Electronic Theses & Dissertations

NANOCOMPOSITES OF POLYPYRROLE AND COBALT OXIDE AS EFFICIENT AND STABLE MULTIFUNCTIONAL MATERIALS FOR SUPERCAPACITORS AND OVERALL WATER SPLITTING

An Abstract of the Thesis by

Ahlam Alghamdi

The main objective of this study is to synthesize nanostructured cobalt oxide decorated on polypyrrole using a facile method for energy applications. For this, polypyrrole was first synthesized using a chemical polymerization method. In the second step, a varying amount of cobalt oxide was decorated on polypyrrole using a hydrothermal process. The synthesized materials were structurally and electrochemically characterized. It was observed that the electrochemical properties of the composites depend on their composition. The …

Designing A Calibration Set In Spectral Space For Efficient Development Of An Nir Method For Tablet Analysis, Md Anik Alam

Electronic Theses and Dissertations

Designing a calibration set is the first step in developing a spectroscopic calibration method for quantitative analysis of pharmaceutical tablets. This step is critical because successful model development depends on the suitability of the calibration data. For spectroscopic-based methods, traditional concentration based techniques for designing calibration sets are prone to have redundant information while simultaneously lacking necessary information for a successful calibration model. The traditional method also follows the same design approach for different spectroscopic techniques and different formulations, thereby lacks the optimizing capability to be technique and formulation specific.

A method for designing a calibration set in the Near …

Effects Of A Green Chemistry Laboratory Design On First- Semester General Chemistry Students' Transformative Experiences In Chemistry, Lurea Joan Doody

Electronic Theses and Dissertations

The purpose of this study was to understand if a green chemistry laboratory design facilitated students’ transformative experiences in a first-semester general chemistry course for science majors. The study population consisted of 18 college students enrolled in the course at a small, rural, mid-Atlantic university. Traditional chemistry laboratories were replaced with three signature green chemistry laboratories over a period of 6-weeks at the end of the spring semester. Impact data were collected pre- and post, of the three labs using the Transformative Experience Questionnaire (TEQ) surveys. Open ended guided reflection questions were coded for elements of transformative experience (TE): expansion …