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2016

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Articles 901 - 930 of 1435

Full-Text Articles in Chemistry

Multi-Frequency Ferromagnetic Resonance Investigation Of Nickel Nanocubes Encapsulated In Diamagnetic Magnesium Oxide Matrix, Saritha Nellutla, Sudhakar Nori, Srinivasa R. Singamaneni, John T. Prater, Jagdish Narayan, Alix I. Smirnov Jan 2016

Multi-Frequency Ferromagnetic Resonance Investigation Of Nickel Nanocubes Encapsulated In Diamagnetic Magnesium Oxide Matrix, Saritha Nellutla, Sudhakar Nori, Srinivasa R. Singamaneni, John T. Prater, Jagdish Narayan, Alix I. Smirnov

Chemical Sciences Faculty Publications

Partially aligned nickel nanocubes were grown epitaxially in a diamagnetic magnesium oxide (MgO:Ni) host and studied by a continuous wave ferromagnetic resonance (FMR) spectroscopy at the X-band (9.5 GHz) from ca. 117 to 458 K and then at room temperature for multiple external magnetic fields/resonant frequencies from 9.5 to 330 GHz. In contrast to conventional magnetic susceptibility studies that provided data on the bulk magnetization, the FMR spectra revealed the presence of three different types of magnetic Ni nanocubes in the sample. Specifically, three different ferromagnetic resonances were observed in the X-band spectra: a line 1 assigned to large nickel …


The Role Of Open Lead Interactions In Atmospheric Ozone Variability Between Arctic Coastal And Inland Sites, Peter K. Peterson, Kerri A. Pratt, William R. Simpson, Son V. Nghiem, Lemuel X. Pérez Pérez, Eric J. Boone, Denis Pöhler, Johannes Zielcke, Stephan General, Paul B. Shepson, Udo Frieß, Ulrich Platt, Brian H. Stirm Jan 2016

The Role Of Open Lead Interactions In Atmospheric Ozone Variability Between Arctic Coastal And Inland Sites, Peter K. Peterson, Kerri A. Pratt, William R. Simpson, Son V. Nghiem, Lemuel X. Pérez Pérez, Eric J. Boone, Denis Pöhler, Johannes Zielcke, Stephan General, Paul B. Shepson, Udo Frieß, Ulrich Platt, Brian H. Stirm

Chemistry

Boundary layer atmospheric ozone depletion events (ODEs) are commonly observed across polar sea ice regions following polar sunrise. During March-April 2005 in Alaska, the coastal site of Barrow and inland site of Atqasuk experienced ODEs (O3 < 10 nmol mol-1) concurrently for 31% of the observations, consistent with large spatial scale ozone depletion. However, 7% of the time ODEs were exclusively observed inland at Atqasuk. This phenomenon also occurred during one of nine flights during the BRomine, Ozone, and Mercury EXperiment (BROMEX), when atmospheric vertical profiles at both sites showed near-surface ozone depletion only at Atqasuk on 28 March 2012. Concurrent in-flight BrO measurements made using nadir scanning differential optical absorption spectroscopy (DOAS) showed the differences in ozone vertical profiles at these two sites could not be attributed to differences in locally occurring halogen chemistry. During both studies, backward air mass trajectories showed that the Barrow air masses observed had interacted with open sea ice leads, causing increased vertical mixing and recovery of ozone at Barrow and not Atqasuk, where the air masses only interacted with tundra and consolidated sea ice. These observations suggest that, while it is typical for coastal and inland sites to have similar ozone conditions, open leads may cause heterogeneity in the chemical composition of the springtime Arctic boundary layer over coastal and inland areas adjacent to sea ice regions.


Development And Validation Of Uplc/Ms/Ms Methods For Quantification Of Gangliosides In The Clinical Study Of Ganglioside Gm3 Synthase Deficiency, Qianyang Huang Jan 2016

Development And Validation Of Uplc/Ms/Ms Methods For Quantification Of Gangliosides In The Clinical Study Of Ganglioside Gm3 Synthase Deficiency, Qianyang Huang

ETD Archive

Gangliosides are a large subclass of glycosphingolipids that structurally characterized by the addition of mono- or poly-sialyated carbohydrate moieties onto the ceramide scaffold. They are presented at significant abundance in the central nervous system of vertebrates. Their interactions with trans-membrane receptors, especially receptor tyrosine kinase, are believed to play critical roles in modulating signal transduction events during cell proliferation, differentiation, migration, and adhesion. Furthermore, the disruption and dysfunction on their metabolism have been found to be associated with various neurodegenerative disorders, such as Alzheimer disease, Parkinson’s disease, and GM3 synthase deficiency. GM3 synthase deficiency (GSD) is a newly identified neurological …


Study Of Electron Transfer Through The Reductase Domain Of Neuronal Nitric Oxide Synthase And Development Of Bacterial Nitric Oxide Synthase Inhibitors, Yue Dai Jan 2016

Study Of Electron Transfer Through The Reductase Domain Of Neuronal Nitric Oxide Synthase And Development Of Bacterial Nitric Oxide Synthase Inhibitors, Yue Dai

ETD Archive

Crystal structure of neuronal Nitric Oxide Synthase reductase (nNOSr) implies that large-scale domain motion is essential for electron transfer. However, the details are not well understood. To address this, we generated a functioning “Cys-lite” version of nNOSr and then replaced the nNOSr Glu816 and Arg1229 residues with Cys in the FMN and FAD domains (CL5SS) in order to allow cross-domain disulfide bond formation under pH 9 or to cross-linking using bis-maleimides. Cross-linked CL5SS exhibited a =95% decrease in cytochrome c reductase activity and reduction of the disulfide bond restored the activities. The results demonstrate that a conformational equilibrium involving FMN …


Application Of Advanced Analytical Technologies To Drug Development Studies And Cancer Detection, Ramakrishna Reddy Voggu Jan 2016

Application Of Advanced Analytical Technologies To Drug Development Studies And Cancer Detection, Ramakrishna Reddy Voggu

ETD Archive

In the past decade, bioanalytical method development has become an integral part of the clinical diagnosis, biomarker discovery, and drug discovery and development. The new and emerged bioanalytical techniques allow the quantitative and qualitative analysis of bio molecules with remarkably high sensitivity and specificity. Specifically, these bioanalytical methods based on LC-MS and methylation-specific PCR are well suited for detecting low-abundance metabolites in various biological fluids and DNA in plasma and tissues for biomarker investigation. They offer great clinical promise for early disease diagnosis and therapeutic intervention. This dissertation broadly organized into two parts, part one talks about the application of …


The Determination Of Caffeine Content In Decaffeinated Blackbird Coffee, Logan Chalmers Jan 2016

The Determination Of Caffeine Content In Decaffeinated Blackbird Coffee, Logan Chalmers

The Corinthian

Caffeine is a central nervous system stimulant that increases one’s metabolic rate, alertness and motivation upon consumption. Consumer curiosity sparked the investigation of the caffeine content found in locally brewed Blackbird Coffee. A procedure involving liquid-liquid extraction with dichloromethane was developed to determine the amount of caffeine in store-bought, brewed caffeinated and decaffeinated coffee. The caffeine amounts recovered were reproducible, thus the method was proved reliable and was implemented for the extraction of caffeine from Blackbird decaffeinated coffee. A single serving was determined to contain an average of 39 ± 12 mg of caffeine which is approximately 20% of the …


Encapsulating Ibuprofen Using Beeswax Microspheres, Chau To, Kermin Martinez-Hernandez Jan 2016

Encapsulating Ibuprofen Using Beeswax Microspheres, Chau To, Kermin Martinez-Hernandez

Undergraduate External Publications

Beeswax is extremely versatile, often used in candles, lubricants. This compound is readily available and is not very expensive. We are interested in using beeswax as a biodegradable capsule to self-encapsulate drugs like ibuprofen.


Glen Helen And Little Miami River Water Quality Fall 2015, Steven J. Ujvary, Sarah Izor, Lin Phu, Lauren Bruce, Justin Myers, Jessica Clemmons, Amy Mcneely, Ashlynn Boedecker, Ritu Ghose, Jessica Mckinley, Audrey E. Mcgowin Jan 2016

Glen Helen And Little Miami River Water Quality Fall 2015, Steven J. Ujvary, Sarah Izor, Lin Phu, Lauren Bruce, Justin Myers, Jessica Clemmons, Amy Mcneely, Ashlynn Boedecker, Ritu Ghose, Jessica Mckinley, Audrey E. Mcgowin

Chemistry Faculty Publications

Service Learning Intensive (SVI) - a teaching and learning pedagogy that engages faculty, students, and community members in a partnership to achieve academic learning objectives, meet community needs, promote civic responsibility, and reflect on the learning experience.

More specifically, the objectives for this course are for students to:

  • Apply environmental chemistry concepts learned in the classroom to the interpretation environmental analysis results
  • Use Good Laboratory Practice (GLP) through the use of Standard Operating Procedures (SOPs) and EPA methods for the analysis of metals, anions, dissolved oxygen, pH, temperature, conductivity, ammonia, and turbidity
  • Follow up on previous years’ results showing elevated …


Final Report: Storm Water Pollutant Inputs To The Little Miami River Via Yellow Springs And Birch Creeks, Audrey E. Mcgowin Jan 2016

Final Report: Storm Water Pollutant Inputs To The Little Miami River Via Yellow Springs And Birch Creeks, Audrey E. Mcgowin

Chemistry Faculty Publications

This report describes the results of research performed with funds from the Sture Fredrik Anliot Grant Fund granted in March 2015. The primary aim of the project was to identify and measure various stormwater pollutant inputs to Yellow Springs Creek and Birch Creek into Glen Helen Nature Preserve and then into the Little Miami River in Greene County, Ohio from Spring 2015 to Winter 2016.

In order to better understand pollutant flow into Glen Helen and subsequently into the Little Miami River, three different types of samples were taken. One type of sample was a “grab” sample taken under normal …


A Comprehensive Exploration Of The Conformational And Energetic Landscape Of A Rotaxane System: A Molecular Dynamics Study, Kentaro Bodzewski, Andrew Johnson Jan 2016

A Comprehensive Exploration Of The Conformational And Energetic Landscape Of A Rotaxane System: A Molecular Dynamics Study, Kentaro Bodzewski, Andrew Johnson

CUP Undergraduate Research

Rotaxanes are composed of a dumbbell shaped molecule threaded through a ring shaped macrocycle; see Figure1. Rotaxanes are used in molecular machines due to the thread’s ability to rotate (pirouette) within the macrocycle. This rotation is often coupled with a shuttling movement as well making them especially useful. Unfortunately, rotaxanes are extremely difficult to synthesize, making it a challenge to study them. By being able to study them using molecular dynamics, one can predict their conformational energies before having to create them. In a previous study, energy barrier values were found for three DAP based rotaxane pirouettes using NMR spectroscopy. …


I Want To Be The Inquiry Guy! How Research Experiences For Teachers Change Beliefs, Attitudes, And Values About Teaching Science As Inquiry, Deborah Herrington, Senetta F. Bancroft, Molly M. Edwards, Caroline J. Schairer Jan 2016

I Want To Be The Inquiry Guy! How Research Experiences For Teachers Change Beliefs, Attitudes, And Values About Teaching Science As Inquiry, Deborah Herrington, Senetta F. Bancroft, Molly M. Edwards, Caroline J. Schairer

Peer Reviewed Articles

This qualitative study examined how and why a research experiences for teachers (RET) influenced middle and high school science teachers’ beliefs, attitudes, and values about teaching science as inquiry. Changes teachers reported after participating in the RET ranged from modifying a few lessons (belief change) to a comprehensive revision of what and how they taught to better reflect inquiry (attitude change). Some teachers who described comprehensively changing their instruction also described implementing actions meant to change science education within their respective schools, not just their own classrooms (value change). We present how and why teachers went about changes in their …


Effects Of Surface Coatings On Crystalization Of Calcium Sulfate, Shawn Pj Kirby, Josiah Reams, Kamran Ghiassi, Jeffrey Alston Jan 2016

Effects Of Surface Coatings On Crystalization Of Calcium Sulfate, Shawn Pj Kirby, Josiah Reams, Kamran Ghiassi, Jeffrey Alston

STAR Program Research Presentations

Deposits from hard water can be problematic as they can form scaling on boilers and cooling towers. Scaling can reduce thermal efficiency. Coatings can be used to prevent mineral fouling by changing the surface energy. Some deposits have inverse solubility; such as calcium sulfate. This means that as temperature rises, they become less soluble and can crystallize out of solution. Calcium sulfate is often found in hard water. Crystalization tests were done to determine how coatings such as various POSS (Polyhedral oligomeric silsesquioxane) compounds acted as nucleating surfaces for calcium sulfate. POSS compounds were tested in particular because they …


Teaching Climate Change Concepts And The Nature Of Science: A Library Activity To Identify Sources Of Climate Change Misconceptions, Charity Flener Lovitt, Kristen S. Shuyler Jan 2016

Teaching Climate Change Concepts And The Nature Of Science: A Library Activity To Identify Sources Of Climate Change Misconceptions, Charity Flener Lovitt, Kristen S. Shuyler

Libraries

A library activity was developed in which students found information about climate science misconceptions from popular and scientific literatures. As part of the activity, students developed a rubric to evaluate the credibility and type of literature sources they found. The activity prepared students to produce an annotated bibliography of articles, which they then used to create a training document about a climate science misconception for staff at a local science center. Evaluation of annotated bibliographies showed that students were able to distinguish between popular and scholarly literature but struggled to identify primary and secondary sources within the scholarly literature. In …


Microbial-Physical Synthesis Of Fe And Fe3o4 Magnetic Nanoparticles Using Aspergillus Niger Yesm1 And Supercritical Condition Of Ethanol, Mai Abdeen, Soraya Sabry, Hanan Ghozlan, Ahmed A. El-Gendy, Everett E. Carpenter Jan 2016

Microbial-Physical Synthesis Of Fe And Fe3o4 Magnetic Nanoparticles Using Aspergillus Niger Yesm1 And Supercritical Condition Of Ethanol, Mai Abdeen, Soraya Sabry, Hanan Ghozlan, Ahmed A. El-Gendy, Everett E. Carpenter

Chemistry Publications

Magnetic Fe and Fe3O4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO4 and FeCl3 to FeS and Fe2O3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300∘ C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe3O4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe3O4. The magnetic properties are measured to exhibit …


Identification Of Rnase-Resistant Rnas In Saccharomyces Cerevisiae Extracts: Separation From Chromosomal Dna By Selective Precipitation, Blanca V. Rodriguez, Eric T. Malczewskyj, Joshua M. Cabiya, L Kevin Lewis, Corina Maeder Jan 2016

Identification Of Rnase-Resistant Rnas In Saccharomyces Cerevisiae Extracts: Separation From Chromosomal Dna By Selective Precipitation, Blanca V. Rodriguez, Eric T. Malczewskyj, Joshua M. Cabiya, L Kevin Lewis, Corina Maeder

Chemistry Faculty Research

High-quality chromosomal DNA is a requirement for many biochemical and molecular biological techniques. To isolate cellular DNA, standard protocols typically lyse cells and separate nucleic acids from other biological molecules using a combination of chemical and physical methods. After a standard chemical-based protocol to isolate chromosomal DNA from Saccharomyces cerevisiae and then treatment with RNase A to degrade RNA, two RNase-resistant bands persisted when analyzed using gel electrophoresis. Interestingly, such resistant bands did not appear in preparations of Escherichia coli bacterial DNA after RNase treatment. Several enzymatic, chemical, and physical methods were employed in an effort to remove the resistant …


C-Reactive Protein Interactions With Cellular Membranes And Supported Lipid Bilayers, Aml Abd Alhamed Alnaas Jan 2016

C-Reactive Protein Interactions With Cellular Membranes And Supported Lipid Bilayers, Aml Abd Alhamed Alnaas

Electronic Theses and Dissertations

C-reactive protein (CRP) is a serum protein that binds to damaged membranes and initiates the complement immune response. Different forms of CRP are thought to alter how the body responds to inflammation and the degradation of foreign material. Despite knowing that a modified form of CRP(mCRP) binds to downstream protein binding partners better than the native pentameric form, the role of CRP conformation on lipid binding is yet unknown. In this work, three main assays were performed to characterize how conformation affects CRP-membrane interactions. The first assay utilized supported lipid bilayers that mimic the plasma membrane of apoptotic cells. The …


Source Apportionment Of Atmospheric Particulate Matter In Developing Countries Using Trace Elements And Stable Metal Isotope Ratios, Nitika Dewan Jan 2016

Source Apportionment Of Atmospheric Particulate Matter In Developing Countries Using Trace Elements And Stable Metal Isotope Ratios, Nitika Dewan

Electronic Theses and Dissertations

The work presented herein details the source apportionment of atmospheric particulate matter in developing countries (Kyrgyzstan in Central Asia, metropolitan cities in Northern India, and Shenzhen in China) using trace elements and stable metal isotope ratios. The first study focused on the development of a novel method for the concomitant separation of rare-earth elements in environmental samples of any geological origin. The separation procedure is based on three extraction chromatographic materials, referred to as Sr.Spec, TRU.Spec, and Ln.Spec. This triple column arrangement enables the simultaneous isolation of pure Sr and Nd fractions in less than one day and with great …


Relaxation Of Metals And Their Impact On Nitroxides, Priyanka Aggarwal Jan 2016

Relaxation Of Metals And Their Impact On Nitroxides, Priyanka Aggarwal

Electronic Theses and Dissertations

Pulsed and continuous wave electron spin resonance were used to characterize the relaxation rates of selected paramagnetic metals at 5 to 15 K or 80 K, measure the impact of these rapidly relaxing metals on the relaxation rates of nitroxide radicals in glassy mixtures and in discrete complexes, and characterize novel iron-sulfur proteins.

Spin echoes were observed at 5 to 7 K in 1:1 water:glycerol for Er(diethylenetriamine pentaacetic acid)2- (Er(DTPA)2-), Co(DTPA)3- and aquo Co2+ with relaxation times that are strongly temperature dependent. Deep proton modulation was present on spin echo decays (Ch. 3). For Gd …


Quinolines: Novel Synthesis And Derivatives Of Heterocyclic Bioactive Agents, Ginelle A. Ramann Jan 2016

Quinolines: Novel Synthesis And Derivatives Of Heterocyclic Bioactive Agents, Ginelle A. Ramann

Electronic Theses and Dissertations

Tuberculosis is a pulmonary disease that has ravaged the world throughout history. Even today, many developed and developing countries are experiencing this plight, made worse by the scourge of antibiotic-resistant bacteria.

Mycobacterium tuberculosis's class II fructose-1,6-bisphosphate aldolase presents an interesting target in the design of new therapies against this disease. Previous attempts to construct an inhibitor to this enzyme fell short due to poor selectivity or poor cellular uptake. However a new class of noncompetitive inhibitor based on 8-hydoxyquinoline-2-carboxylic acid presents a fresh approach. Preliminary studies indicate various modifications to this scaffold could be beneficial to its inhibitory efficacy.

Modifications …


Deciphering The Mode Of Action Of The Processive Polysaccharide Modifying Enzyme Dermatan Sulfate Epimerase 1 By Hydrogen-Deuterium Exchange Mass Spectrometry, Emil Tykesson, Yang Mao, Marco Maccarana, Yi Pu, Jinshan Gao, Cheng Lin, Joseph Zaia, Gunilla Westergren-Thorsson, Ulf Ellervik, Lars Malmström, Anders Malmström Jan 2016

Deciphering The Mode Of Action Of The Processive Polysaccharide Modifying Enzyme Dermatan Sulfate Epimerase 1 By Hydrogen-Deuterium Exchange Mass Spectrometry, Emil Tykesson, Yang Mao, Marco Maccarana, Yi Pu, Jinshan Gao, Cheng Lin, Joseph Zaia, Gunilla Westergren-Thorsson, Ulf Ellervik, Lars Malmström, Anders Malmström

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Distinct from template-directed biosynthesis of nucleic acids and proteins, the enzymatic synthesis of heterogeneous polysaccharides is a complex process that is difficult to study using common analytical tools. Therefore, the mode of action and processivity of those enzymes are largely unknown. Dermatan sulfate epimerase 1 (DS-epi1) is the predominant enzyme during the formation of iduronic acid residues in the glycosaminoglycan dermatan sulfate. Using recombinant DS-epi1 as a model enzyme, we describe a tandem mass spectrometry-based method to study the mode of action of polysaccharide processing enzymes. The enzyme action on the substrate was monitored by hydrogen-deuterium exchange mass spectrometry and …


Hydrogen Production With A Simple And Scalable Membraneless Electrolyzer, Glen O'Neil, Corey D. Christian, David E. Brown, Daniel V. Esposito Jan 2016

Hydrogen Production With A Simple And Scalable Membraneless Electrolyzer, Glen O'Neil, Corey D. Christian, David E. Brown, Daniel V. Esposito

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Ion-conducting membranes are essential components in many electrochemical devices, but they often add substantial cost, limit performance, and are susceptible to degradation. This work investigates membraneless electrochemical flow cells for hydrogen production from water electrolysis that are based on angled mesh flow-through electrodes. These devices can be fabricated with as few as three parts (anode, cathode, and cell body), reflecting their simplicity and potential for low-cost manufacture. 3D printing was used to fabricate prototype electrolyzers that were demonstrated to be electrolyte agnostic, modular, and capable of operating with minimal product crossover. Prototype electrolyzers operating in acidic and alkaline solutions achieved …


Functionalized Cationic [4]Helicenes With Unique Tuning Of Absorption, Fluorescence And Chiroptical Properties Up To The Far-Red Range, I. Hernández Delgado, S. Pascal, A. Wallabregue, R. Duwald, C. Besnard, L. Guénée, C. Nançoz, E. Vauthey, R. Tovar, J. Lunkley, Gilles Muller, J. Lacour Jan 2016

Functionalized Cationic [4]Helicenes With Unique Tuning Of Absorption, Fluorescence And Chiroptical Properties Up To The Far-Red Range, I. Hernández Delgado, S. Pascal, A. Wallabregue, R. Duwald, C. Besnard, L. Guénée, C. Nançoz, E. Vauthey, R. Tovar, J. Lunkley, Gilles Muller, J. Lacour

Faculty Publications, Chemistry

Unprecedented regioselective post-functionalization of racemic and enantiopure cationic diaza [4]helicenes is afforded. The peripheral auxochrome substituents allow a general tuning of the electrochemical, photophysical and chiroptical properties of the helical dyes (26 examples). For instance, electronic absorption and circular dichroism are modulated from the orange to near-infrared spectral range (575–750 nm), fluorescence quantum efficiency is enhanced up to 0.55 (631 nm) and circularly polarized luminescence is recorded in the red (|glum| ∼ 10−3).


Density Functional Investigation Of The Inclusion Of Gold Clusters On A Ch3s Self-Assembled Lattice On Au(111), Darnel J. Allen, Wayne E. Archibald, John A. Harper, John C. Saputo, Daniel Torres Jan 2016

Density Functional Investigation Of The Inclusion Of Gold Clusters On A Ch3s Self-Assembled Lattice On Au(111), Darnel J. Allen, Wayne E. Archibald, John A. Harper, John C. Saputo, Daniel Torres

Publications and Research

We employ first-principles density functional theoretical calculations to address the inclusion of gold (Au) clusters in a well-packed CH3S self-assembled lattice. We compute CH3S adsorption energies to quantify the energetic stability of the self-assembly and gold adsorption and dissolution energies to characterize the structural stability of a series of Au clusters adsorbed at the SAM-Au interface. Our results indicate that the inclusion of Au clusters with less than four Au atoms in the SAM-Au interface enhances the binding of CH3S species. In contrast, larger Au clusters destabilize the self-assembly.We attribute this effect to the low-coordinated gold atoms in the cluster. …


Towards Structural Determination Of Human Α1-Glycine Receptor Allostery, Rathna Jyothi Veeramachaneni Jan 2016

Towards Structural Determination Of Human Α1-Glycine Receptor Allostery, Rathna Jyothi Veeramachaneni

Electronic Theses and Dissertations

Recent advances in technology have led to the determination of numerous notable structures of membrane proteins. While they provide valuable information about the structure of membrane proteins these studies often provide static images with potentially limited dynamics, and structural determination often requires truncation of flexible regions, and often utilizes bacterial homologs given the need for stable, heterologous overexpression. In order to better understand allostery at a molecular level, state-dependent crosslinking studies coupled with multidimensional mass spectrometry (MS) were conducted on glycine receptor (GlyR) stabilized in different allosteric states. Predominant allosteric states were stabilized using wild type or mutated receptor in …


Syntheses And Characterization Of [4]Ferrocenophane, Ahmed Sabah Al-Doori Jan 2016

Syntheses And Characterization Of [4]Ferrocenophane, Ahmed Sabah Al-Doori

Theses, Dissertations and Capstones

Metallocenophanes are metallocenes in which the cyclopentadienyl ligands are connected by a molecular bridge. Recently, metallocenophanes have received increasing attention because of their structure, chemical reactivity, and potential use as building blocks for new materials. Even though metallocenophanes have been synthesized by different methods, the majority of these methods involved the use of iron with rare examples of other metals. Therefore, a new method was employed that in addition to making ferrocenophane, will allow us to synthesize metallocenophanes with V, Cr, Mn, Co, and Ni as central metals. This thesis reports the synthesis of [4]ferrocenophane via a “flytrap” route. The …


Development Of Palladium Catalyzed Alkene Difunctionalization On Vinyl-Quinoline Type Substrate And Isolation Of Pd-Alkyl Intermediate, Lusha Xu Jan 2016

Development Of Palladium Catalyzed Alkene Difunctionalization On Vinyl-Quinoline Type Substrate And Isolation Of Pd-Alkyl Intermediate, Lusha Xu

Electronic Theses and Dissertations

The synthesis of quinoline derivatives is a continuing issue facing organic chemists in both academia and industry. To address this problem, palladium-catalyzed alkene difunctionalization was developed to be a powerful and straightforward strategy of synthetic transformations for adding diversity to organic molecules. In this thesis, Pd-catalyzed olefin difunctionalization reactions of vinyl-quinoline type substrate via generating Pd-alkyl intermediates were mainly described. The reactions described herein are pursuing three significant goals: 1) to isolate and recrystallize Pd-alkyl complexes; 2) to achieve oxidation reactions on Pd-alkyl intermediate; and 3) to investigate stereochemistry of nucleopalladation step on vinyl-quinoline starting materials.


Determination Of Hexavalent Chromium (Cr(Vi)) Concentrations Via Ion Chromatography And Uv-Vis Spectrophotometry In Samples Collected From Nacogdoches Wastewater Treatment Plant, East Texas (Usa), Kefa Karimu Onchoke, Salomey A. Sasu Jan 2016

Determination Of Hexavalent Chromium (Cr(Vi)) Concentrations Via Ion Chromatography And Uv-Vis Spectrophotometry In Samples Collected From Nacogdoches Wastewater Treatment Plant, East Texas (Usa), Kefa Karimu Onchoke, Salomey A. Sasu

Faculty Publications

The concentration of hexavalent chromium (Cr(VI)), a toxic environmental pollutant and carcinogen, was determined in samples collected from Nacogdoches Wastewater Treatment Plant (NWWTP) using ion chromatography and UV-visible spectrophotometry (IC, UV-Vis). On reaction with 1,5-diphenylcarbazide (DPC) Cr+6 forms a 1,5-diphenylcarbazide-Cr(VI) complex, which is then analyzed at 530nm and 540nm, respectively. Via ion chromatography Cr(VI) concentrations were in the range of 0.00190 ± 0.0020 and 0.0010 ± 0.0006ppm at the influent and effluent, respectively. With the use of standard addition wastewater samples were spiked with a 0.5ppm Cr(VI) standard of various amounts and subsequently analyzed with UV-Vis spectrophotometry. The spiked concentrations …


Water Soluble Cationic Porphyrin Sensor For Detection Of Hg2+, Pb2+, Cd2+, And Cu2+, Matibur Zamadar, Christopher Orr, Miranda Uherek Jan 2016

Water Soluble Cationic Porphyrin Sensor For Detection Of Hg2+, Pb2+, Cd2+, And Cu2+, Matibur Zamadar, Christopher Orr, Miranda Uherek

Faculty Publications

Here we report the sensing properties of the aqueous solution of meso-tetra(N-methyl-4-pyridyl)porphine tetrachloride (1) for simultaneous detection of toxic metal ions by using UV-vis spectroscopy. Cationic porphyrin 1 displayed different electronic absorptions in UV-vis region upon interacting with Hg2+, Pb2+, Cd2+, and Cu2+ ions in neutral water solution at room temperature. Quite interestingly, the porphyrin 1 showed that it can function as a single optical chemical sensor and/or metal ion receptor capable of detecting two or more toxic metal ions, particularly Hg2+, Pb2+, and Cd2+ ions coexisting in a water sample. Porphyrin 1 in an aqueous solution provides a unique …


"High-Valent Copper In Biomimetic And Biological Oxidations", J. Brannon Gary Jan 2016

"High-Valent Copper In Biomimetic And Biological Oxidations", J. Brannon Gary

Faculty Publications

A long-standing debate in the Cu-O2 field has revolved around the relevance of the Cu(III) oxidation state in biological redox processes. The proposal of Cu(III) in biology is generally challenged as no spectroscopic or structural evidence exists currently for its presence. The reaction of synthetic Cu(I) complexes with O2 at low temperature in aprotic solvents provides the opportunity to investigate and define the chemical landscape of Cu-O2 species at a small molecule level of detail; eight different types are characterized structurally, three of which contain at least one Cu(III) center. Simple imidazole or histamine ligands are competent in these oxygenation …


Spectrophotometric Analysis Of Urinary Iodine In 18-22 Year-Old Women In Central Minnesota, Haley Chatelaine Jan 2016

Spectrophotometric Analysis Of Urinary Iodine In 18-22 Year-Old Women In Central Minnesota, Haley Chatelaine

All College Thesis Program, 2016-2019

Iodine is an overlooked but incredibly important micronutrient, especially with regard to early fetus development. The United States does not mandate salt iodization, so widely consumed processed foods are not likely to contain iodized salt, which may potentially put the population at risk for developing iodine deficiencies. Therefore, the purpose of this study is to correspond iodine intake to iodine status and establish effective methods for determining a relationship between the two. Subjects (n=23) completed a food survey and supplied 50mL urine samples to compare an estimated average daily iodine intake based on foods over the course of a week …