Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 12091 - 12120 of 33361

Full-Text Articles in Chemistry

Detection Of Salen-Type Tracers For Subterranean Fluid Flow Monitoring Using Surface-Enhanced Raman Spectroscopy, Jenny C. Sanchez May 2018

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 May 2018

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 May 2018

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 May 2018

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 May 2018

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 …


Tetrel Bonding As A Vehicle For Strong And Selective Anion Binding, Steve Scheiner May 2018

Tetrel Bonding As A Vehicle For Strong And Selective Anion Binding, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Tetrel atoms T (T = Si, Ge, Sn, and Pb) can engage in very strong noncovalent interactions with nucleophiles, which are commonly referred to as tetrel bonds. The ability of such bonds to bind various anions is assessed with a goal of designing an optimal receptor. The Sn atom seems to form the strongest bonds within the tetrel family. It is most effective in the context of a -SnF3 group and a further enhancement is observed when a positive charge is placed on the receptor. Connection of the -SnF3 group to either an imidazolium or triazolium provides a strong halide …


Organic Compound Emissions From A Landfarm Used For Oil And Gas Solid Waste Disposal, Seth N. Lyman, Marc L. Mansfield May 2018

Organic Compound Emissions From A Landfarm Used For Oil And Gas Solid Waste Disposal, Seth N. Lyman, Marc L. Mansfield

Chemistry and Biochemistry Faculty Publications

Solid or sludgy hydrocarbon waste is a byproduct of oil and gas exploration and production. One commonly-used method of disposing of this waste is landfarming. Landfarming involves spreading hydrocarbon waste on soils, tilling it into the soil, and allowing it to biodegrade. We used a dynamic flux chamber to measure fluxes of methane, a suite of 54 non-methane hydrocarbons, and light alcohols from an active and a remediated landfarm in eastern Utah, U.S.A. Fluxes from the remediated landfarm were not different from a PTFE sheet or from undisturbed soils in the region. Fluxes of methane, total non-methane hydrocarbons, and alcohols …


Effects Of A Green Chemistry Laboratory Design On First- Semester General Chemistry Students' Transformative Experiences In Chemistry, Lurea Joan Doody May 2018

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 …


Designing A Calibration Set In Spectral Space For Efficient Development Of An Nir Method For Tablet Analysis, Md Anik Alam May 2018

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 …


Targeted Triple Drug Regimen For The Treatment Of Prostate Cancer, Tanuja Tummala May 2018

Targeted Triple Drug Regimen For The Treatment Of Prostate Cancer, Tanuja Tummala

Electronic Theses & Dissertations

Prostate cancer is the most common amongst men. According to ACS 2018 statistics, about 164,690 new cases appear and 29,430 deaths occur. Nearly 6 in 10 cases are diagnosed in men over 50 years of age and often there are no early symptoms. The treatment options include surgery, chemotherapy, hormonal therapy and/or radiation and it can often be treated successfully. However, the poor management and adverse effects demanded ways to find better treatment option. Towards the development of a personalized medicine for prostate cancer treatment, we proposed to design prostate cancer targeting magnetic nanoplatform. This integrates various key components such …


Lipophilic Chemicals From Diesel Exhaust Particles Trigger Calcium Response In Human Endothelial Cells Via Aryl Hydrocarbon Receptor Non-Genomic Signalling, Alena Kubatova, Bendik C. Brinchmann, Eric Le Ferrec, Normand Podechard, Dominique Lagadic-Gossmann, Kenji F. Shoji, Aubin Penna, Klara Kukowski, Jorn A. Holme, Johan Ovrevik May 2018

Lipophilic Chemicals From Diesel Exhaust Particles Trigger Calcium Response In Human Endothelial Cells Via Aryl Hydrocarbon Receptor Non-Genomic Signalling, Alena Kubatova, Bendik C. Brinchmann, Eric Le Ferrec, Normand Podechard, Dominique Lagadic-Gossmann, Kenji F. Shoji, Aubin Penna, Klara Kukowski, Jorn A. Holme, Johan Ovrevik

Chemistry Faculty Publications

Exposure to diesel exhaust particles (DEPs) affects endothelial function and may contribute to the development of atherosclerosis and vasomotor dysfunction. As intracellular calcium concentration [Ca2+]i is considered important in myoendothelial signalling, we explored the effects of extractable organic matter from DEPs (DEP-EOM) on [Ca2+]i and membrane microstructure in endothelial cells. DEP-EOM of increasing polarity was obtained by pressurized sequential extraction of DEPs with n-hexane (n-Hex-EOM), dichloromethane (DCM-EOM), methanol, and water. Chemical analysis revealed that the majority of organic matter was extracted by the n-Hex- and DCM-EOM, with polycyclic aromatic hydrocarbons primarily occurring in n-Hex-EOM. …


Methylglyoxal Uptake Coefficients On Aqueous Aerosol Surfaces, David O. De Haan, Natalie G. Jimenez, Alexia De Loera, Mathieu Cazaunau, Aline Gratien, Edouard Pangui, Jean-Francois Doussin May 2018

Methylglyoxal Uptake Coefficients On Aqueous Aerosol Surfaces, David O. De Haan, Natalie G. Jimenez, Alexia De Loera, Mathieu Cazaunau, Aline Gratien, Edouard Pangui, Jean-Francois Doussin

Chemistry and Biochemistry: Faculty Scholarship

In order to predict the amount of secondary organic aerosol formed by heterogeneous processing of methylglyoxal, uptake coefficients (γ) and estimates of uptake reversibility are needed. Here, uptake coefficients are extracted from chamber studies involving ammonium sulfate and glycine seed aerosol at high relative humidity (RH ≥ 72%). Methylglyoxal uptake coefficients on prereacted glycine aerosol particles had a strong dependence on RH, increasing from γ = 0.4 × 10–3 to 5.7 × 10–3 between 72 and 99% RH. Continuous methylglyoxal losses were also observed in the presence of aqueous ammonium sulfate at 95% RH (γAS,wet = 3.7 ± 0.8 × …


Development Of A High-Throughput Screening Assay For Potential Inhibitors Against Dna Polymerase Eta, Keri Bryson May 2018

Development Of A High-Throughput Screening Assay For Potential Inhibitors Against Dna Polymerase Eta, Keri Bryson

Honors Program Theses and Projects

All living cells perform DNA replication through a group of enzymes called DNA polymerases. Unfortunately, DNA is constantly exposed to external and internal agents capable of causing damage. DNA damage causes blocks to replication that can be overcome through a special class of DNA polymerases, called the Y-family polymerases; which are able to traverse DNA lesions. Cisplatin is a common chemotherapeutic agent that damages DNA and has been used to treat cancer. However, many patients become resistant to cisplatin. The chemoresistance to cisplatin treatment is due in part to damage bypass performed by the specific Y-family polymerase, polymerase eta. The …


Fast Identification Of Components Commonly Used In Homemade Explosives By Spectroscopic And Chemometric Methods, Deidre Day Vandenbos, Huggins Msimanga, Christopher Dockery May 2018

Fast Identification Of Components Commonly Used In Homemade Explosives By Spectroscopic And Chemometric Methods, Deidre Day Vandenbos, Huggins Msimanga, Christopher Dockery

Master of Science in Chemical Sciences Theses

Homemade explosives (HMEs) have become a global pandemic. This forensic research focuses on developing identification methods that can provide quick, cost effective, non-destructive analysis using portable instrumentation. These capabilities would be invaluable to first responders, military, and security officials to establish an evidentiary link between a suspect and a reference in cases of HMEs, IEDs, arson and environmental contamination.

Modern methods for quick identification of the fuels and oxidant sources used in manufacturing HMEs, include Fourier Transform Infrared (FT-IR) and Raman spectroscopy. Visual confirmation alone, however, is not strong enough to discriminate chemicals with nearly identical spectra, which occurs when …


Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith May 2018

Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding how precipitation isotopes vary spatially and temporally is important for tracer applications. We tested how well month‐to‐month variations in precipitation δ18O and δ2H were captured by sinusoidal cycles, and how well spatial variations in these seasonal cycles could be predicted, across Switzerland. Sine functions representing seasonal cycles in precipitation isotopes explained between 47% and 94% of the variance in monthly δ18O and δ2H values at each monitoring site. A significant sinusoidal cycle was also observed in line‐conditioned excess. We interpolated the amplitudes, phases, and offsets of these sine functions across the landscape, using multiple linear …


Kinetic Studies On The Aqueous Chemistry Of The Glutathione-Methyleneoxindole Conjugate To Model Its Inhibition Of Glyoxalase I, Ariane Borges May 2018

Kinetic Studies On The Aqueous Chemistry Of The Glutathione-Methyleneoxindole Conjugate To Model Its Inhibition Of Glyoxalase I, Ariane Borges

Honors Program Theses and Projects

Glyoxalase I (GxI) is an enzyme that is part of the Glyoxalase system which is responsible for the conversion of methylglyoxal (MG), a byproduct of glycolysis, to lactic acid using glutathione (GSH) as a co-substrate. Methylglyoxal and GSH come together to form the hemithioacetal substrate, which is then transformed into (S)-D-lactoylglutathione. Since MG is a highly reactive compound known to induce cell apoptosis, increasing MG levels in cells by inhibiting GxI should increase cell death. Research into the design, synthesis and testing of different inhibitors of GxI support this hypothesis. We have designed and synthesized a potential inhibitor of GxI, …


Water-Mediated Carbon–Oxygen Hydrogen Bonding Facilitates S-Adenosylmethionine Recognition In The Reactivation Domain Of Cobalamin-Dependent Methionine Synthase, Robert J. Fick, Mary C. Clay, Lucas Vander Lee, Steve Scheiner, Hashim M. Al-Hashimi, Raymond C. Trievel May 2018

Water-Mediated Carbon–Oxygen Hydrogen Bonding Facilitates S-Adenosylmethionine Recognition In The Reactivation Domain Of Cobalamin-Dependent Methionine Synthase, Robert J. Fick, Mary C. Clay, Lucas Vander Lee, Steve Scheiner, Hashim M. Al-Hashimi, Raymond C. Trievel

Chemistry and Biochemistry Faculty Publications

The C-terminal domain of cobalamin-dependent methionine synthase (MetH) has an essential role in catalyzing the reactivation of the enzyme following the oxidation of its cobalamin cofactor. This reactivation occurs through reductive methylation of the cobalamin using S-adenosylmethionine (AdoMet) as the methyl donor. Herein, we examine the molecular recognition of AdoMet by the MetH reactivation domain utilizing structural, biochemical, and computational approaches. Crystal structures of the Escherichia coli MetH reactivation domain in complex with AdoMet, the methyl transfer product S-adenosylhomocysteine (AdoHcy), and the AdoMet analogue inhibitor sinefungin illustrate that the ligands exhibit an analogous conformation within the solvent-exposed substrate binding cleft …


The Role Of Torsional Dynamics On Hole And Exciton Stabilization In Π‐Stacked Assemblies: Design Of Rigid Torsionomers Of A Cofacial Bifluorene, Denan Wang, Maxim Vadimovich Ivanov, Damian Kokkin, John Loman, Jin-Zhe Cai, Scott A. Reid, Rajendra Rathore May 2018

The Role Of Torsional Dynamics On Hole And Exciton Stabilization In Π‐Stacked Assemblies: Design Of Rigid Torsionomers Of A Cofacial Bifluorene, Denan Wang, Maxim Vadimovich Ivanov, Damian Kokkin, John Loman, Jin-Zhe Cai, Scott A. Reid, Rajendra Rathore

Chemistry Faculty Research and Publications

Exciton and charge delocalization across π‐stacked assemblies is of importance in biological systems and functional polymeric materials. To examine the requirements for exciton and hole stabilization, cofacial bifluorene (F2) torsionomers were designed, synthesized, and characterized: unhindered (model) MeF2, sterically hindered tBuF2, and cyclophane‐like CF2, where fluorenes are locked in a perfect sandwich orientation via two methylene linkers. This set of bichromophores with varied torsional rigidity and orbital overlap shows that exciton stabilization requires a perfect sandwich‐like arrangement, as seen by strong excimeric‐like emission only in CF2 and MeF2. …


Mammalian Cell-Derived Vesicles For The Isolation Of Organelle Specific Transmembrane Proteins To Conduct Single Molecule Studies, Faruk H. Moonschi, Ashley M. Fox-Loe, Xu Fu, Christopher I. Richards May 2018

Mammalian Cell-Derived Vesicles For The Isolation Of Organelle Specific Transmembrane Proteins To Conduct Single Molecule Studies, Faruk H. Moonschi, Ashley M. Fox-Loe, Xu Fu, Christopher I. Richards

Chemistry Faculty Publications

Cell-derived vesicles facilitate the isolation of transmembrane proteins in their physiological membrane maintaining their structural and functional integrity. These vesicles can be generated from different cellular organelles producing, housing, or transporting the proteins. Combined with single molecule imaging, isolated organelle specific vesicles can be employed to study the trafficking and assembly of the embedded proteins. Here we present a method for organelle specific single molecule imaging via isolation of ER and plasma membrane vesicles from HEK293T cells by employing OptiPrep gradients and nitrogen cavitation. The isolation was validated through Western blotting, and the isolated vesicles were used to perform single …


The Preparation Of Palladium Complexes Of N-Pyrazolylpropanamide Derivatives, Tyler Palombo 5275714 May 2018

The Preparation Of Palladium Complexes Of N-Pyrazolylpropanamide Derivatives, Tyler Palombo 5275714

Senior Honors Projects, 2010-2019

The reaction of 3,5-dimethylpyrazolyl-N-isopropylpropanamide (L1) with dichloro(1,5-cyclooctadiene)palladium(II) displaces cyclooctadiene forming Cl2Pd(L1)2. This complex has been characterized by NMR and IR spectroscopy, single crystal X-Ray diffraction, and elemental analysis. It is composed of a square planar Pd with trans L1 ligands attached through a pyrazolyl nitrogen and intramolecular hydrogen bonding between the amide and chloride. Similar reactions were carried out with 3,5-dimethylpyrazolylpropanamide (L2), pyrazolyl-N-isopropylpropanamide (L3), 3-(1H-benzotriazol-1-yl)-N,N-dimethylpropanamide (L4), 3-methylpyrazolylpropanamide (L5), 3-(1H-benzotriazol-1-yl)-2-methylpropanamide (L6), and N-pyrazolypropanamide (L7) presumably forming analogous complexes. This formulation for …


Hydrodeoxygenation Of Pinyon-Juniper Catalytic Pyrolysis Oil Using Red Mud-Supported Nickel Catalysts, Hossein Jahromi, Foster Agblevor May 2018

Hydrodeoxygenation Of Pinyon-Juniper Catalytic Pyrolysis Oil Using Red Mud-Supported Nickel Catalysts, Hossein Jahromi, Foster Agblevor

Biological Engineering Faculty Publications

Red mud (RM) is an alkaline waste generated in the Bayer process of alumina production. In the present study red mud supported nickel catalysts (Ni/RM) were prepared at different concentrations of nickel (10, 20, 30, 40, 50, and 65 wt.%) and used to hydrodeoxygenate (HDO) pinyon-juniper (PJ) catalytic pyrolysis oil. Increasing the nickel content improved the activity of Ni/RM catalysts for HDO reactions. Maximum organic liquid yield (68.6%) was obtained when 40%Ni/RM was used. The upgraded oil had oxygen content of 1.35 wt.% and higher heating value of 45.77 MJ/kg compared to 24.88 wt.% and 28.41 MJ/kg, respectively, for the …


Nmr Studies Of Loaded Microspheres, Ming Huang, Sisi Chen, Rex E. Gerald Ii, Jie Huang, Klaus Woelk May 2018

Nmr Studies Of Loaded Microspheres, Ming Huang, Sisi Chen, Rex E. Gerald Ii, Jie Huang, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

Porous-wall hollow glass microspheres (PWHGMs) are a novel form of glass materials that consist of 1-μm-thick porous silica shells, 20-100 μm in diameter, with a hollow cavity in the center. Utilizing the central cavity for material storage and the porous walls for controlled release is a unique combination that renders PWHGMs a superior vehicle for targeted drug delivery. In this study, NMR spectroscopy was used to characterize PWHGMs for the first time. A vacuum-based loading system was developed to load PWHGMs with various compounds followed by a washing procedure that uses solvents immiscible with the target material. Immiscible binary model …


Sequential And Differential Interaction Of Assembly Factors During Nitrogenase Mofe Protein Maturation, Emilio Jimenez-Vicente, Zhi-Yong Yang, W. Keith Ray, Carlos Echavarri-Erasun, Valerie L. Cash, Luis M. Rubio, Lance C. Seefeldt, Dennis R. Dean May 2018

Sequential And Differential Interaction Of Assembly Factors During Nitrogenase Mofe Protein Maturation, Emilio Jimenez-Vicente, Zhi-Yong Yang, W. Keith Ray, Carlos Echavarri-Erasun, Valerie L. Cash, Luis M. Rubio, Lance C. Seefeldt, Dennis R. Dean

Chemistry and Biochemistry Faculty Publications

Nitrogenases reduce atmospheric nitrogen, yielding the basic inorganic molecule ammonia. The nitrogenase MoFe protein contains two cofactors, a [7Fe-9S-Mo-C-homocitrate] active-site species, designated FeMo-cofactor, and a [8Fe-7S] electron-transfer mediator called P-cluster. Both cofactors are essential for molybdenum-dependent nitrogenase catalysis in the nitrogen-fixing bacterium Azotobacter vinelandii. We show here that three proteins, NafH, NifW, and NifZ, copurify with MoFe protein produced by an A. vinelandii strain deficient in both FeMo-cofactor formation and P-cluster maturation. In contrast, two different proteins, NifY and NafY, copurified with MoFe protein deficient only in FeMo-cofactor formation. We refer to proteins associated with immature MoFe protein in …


Diagnostic Platform For Current Health Status Monitoring, Albert S. Benight, Megan M. Koslen, Matthew W. Eskew May 2018

Diagnostic Platform For Current Health Status Monitoring, Albert S. Benight, Megan M. Koslen, Matthew W. Eskew

Student Research Symposium

Our approach is based on physical measurements of blood plasma and exploits the plethora of information contained in the human plasma proteome, as a reporter of human health status. The assay involves collection and analysis ofthermograms of plasma from human blood measured by differential scanning calorimetry (DSC).

Plasma thermograms arise from the temperature-induced denaturation profile of proteins within blood plasma measured by DSC. This insightful measurement thereby provides a snapshot of the current state of the human plasma proteome which directly informs on overall systemic health. Such measurements have been shown to be highly accurate and sensitive indicators of health …


Metallodithiolate Ligands For Reversing Metal Ion Induced Aggregation Of Beta Amyloid, Eleanor K. Adams, Marilyn Rampersad Mackiewicz May 2018

Metallodithiolate Ligands For Reversing Metal Ion Induced Aggregation Of Beta Amyloid, Eleanor K. Adams, Marilyn Rampersad Mackiewicz

Student Research Symposium

Alzheimer’s Disease (AD) is the sixth leading cause of death in the United States with no known methods to cure, reverse or halt disease progression. The “metal hypothesis” states that FeII, CuII, ZnII, and AlII bind to truncated Aβ peptides and form soluble oligomers which deposit as senile plaques. These plaques play a crucial role in AD pathogenesis. For example, metallated-Aβ aggregates are hypothesized to disrupt membranes or generate a reactive oxygen species (ROS) through redox cycling in the presence of CuI/II or FeIII/II and a reducing agent. ROS can lead …


Small-Angle X-Ray Scattering In Amorphous Silicon: A Computational Study, Durga Paudel, Raymond Atta-Fynn, David A. Drabold, Stephen R. Elliott, Parthapratim Biswas May 2018

Small-Angle X-Ray Scattering In Amorphous Silicon: A Computational Study, Durga Paudel, Raymond Atta-Fynn, David A. Drabold, Stephen R. Elliott, Parthapratim Biswas

Faculty Publications

We present a computational study of small-angle x-ray scattering (SAXS) in amorphous silicon (α-Si) with particular emphasis on the morphology and microstructure of voids. The relationship between the scattering intensity in SAXS and the three-dimensional structure of nanoscale inhomogeneities or voids is addressed by generating large high-quality (α-Si networks with 0.1%–0.3% volume concentration of voids, as observed in experiments using SAXS and positron annihilation spectroscopy. A systematic study of the variation of the scattering intensity in the small-angle scattering region with the size, shape, number density, and the spatial distribution of the voids in the networks is presented. Our results …


Structural Characterization Of The P1+ Intermediate State Of The P-Cluster Of Nitrogenase, Stephen M. Keable, Oleg A. Zadvornyy, Lewis E. Johnson, Bojana Ginovska, Andrew J. Rasmussen, Karamatullah Danyal, Brian J. Eilers, Gregory A. Prussia, Axl X. Levan, Simone Raugei, Lance C. Seefeldt, John W. Peters May 2018

Structural Characterization Of The P1+ Intermediate State Of The P-Cluster Of Nitrogenase, Stephen M. Keable, Oleg A. Zadvornyy, Lewis E. Johnson, Bojana Ginovska, Andrew J. Rasmussen, Karamatullah Danyal, Brian J. Eilers, Gregory A. Prussia, Axl X. Levan, Simone Raugei, Lance C. Seefeldt, John W. Peters

Chemistry and Biochemistry Faculty Publications

Nitrogenase is the enzyme that reduces atmospheric dinitrogen (N2) to ammonia (NH3) in biological systems. It catalyzes a series of single-electron transfers from the donor iron protein (Fe protein) to the molybdenum–iron protein (MoFe protein) that contains the iron–molybdenum cofactor (FeMo-co) sites where N2 is reduced to NH3. The P-cluster in the MoFe protein functions in nitrogenase catalysis as an intermediate electron carrier between the external electron donor, the Fe protein, and the FeMo-co sites of the MoFe protein. Previous work has revealed that the P-cluster undergoes redox-dependent structural changes and that the …


Structure Of Frequency-Interacting Rna Helicase From Neurospora Crassa Reveals High Flexibility In A Domain Critical For Circadian Rhythm And Rna Surveillance, Yalemi Morales, Keith J. Olsen, Jacqueline M. Bulcher, Sean J. Johnson May 2018

Structure Of Frequency-Interacting Rna Helicase From Neurospora Crassa Reveals High Flexibility In A Domain Critical For Circadian Rhythm And Rna Surveillance, Yalemi Morales, Keith J. Olsen, Jacqueline M. Bulcher, Sean J. Johnson

Chemistry and Biochemistry Faculty Publications

The FRH (frequency-interacting RNA helicase) protein is the Neurospora crassa homolog of yeast Mtr4, an essential RNA helicase that plays a central role in RNA metabolism as an activator of the nuclear RNA exosome. FRH is also a required component of the circadian clock, mediating protein interactions that result in the rhythmic repression of gene expression. Here we show that FRH unwinds RNA substrates in vitro with a kinetic profile similar to Mtr4, indicating that while FRH has acquired additional functionality, its core helicase function remains intact. In contrast with the earlier FRH structures, a new crystal form of FRH …


Photoinduced Interfacial Charge Separation Dynamics In Zeolitic Imidazolate Framework, Brian Pattengale, Jier Huang May 2018

Photoinduced Interfacial Charge Separation Dynamics In Zeolitic Imidazolate Framework, Brian Pattengale, Jier Huang

Chemistry Faculty Research and Publications

Owing to their porous structure and tunable framework, zeolitic imidazolate frameworks (ZIFs) have garnered considerable attention as promising photocatalytic materials. However, little is known regarding their photophysical properties. In this work, we report the photoinduced charge separation dynamics in a ZIF-67 thin film through interfacial electron transfer (ET) to methylene blue (MB+) via ultrafast transient absorption spectroscopy. We show that the ET process occurs through two distinct pathways, including an ultrafast (<200 fs) process from the [CoII(mim)2] units located on the surface of ZIF-67 film that are directly in contact with MB+ and a relatively slower ET process …


Dissecting Structure-Encoded Determinants Of Allosteric Cross-Talk Between Post-Translational Modification Sites In The Hsp90 Chaperones, Gabrielle Stetz, Amanda Tse, Gennady M. Verkhivker May 2018

Dissecting Structure-Encoded Determinants Of Allosteric Cross-Talk Between Post-Translational Modification Sites In The Hsp90 Chaperones, Gabrielle Stetz, Amanda Tse, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Post-translational modifications (PTMs) represent an important regulatory instrument that modulates structure, dynamics and function of proteins. The large number of PTM sites in the Hsp90 proteins that are scattered throughout different domains indicated that synchronization of multiple PTMs through a combinatorial code can be invoked as an important mechanism to orchestrate diverse chaperone functions and recognize multiple client proteins. In this study, we have combined structural and coevolutionary analysis with molecular simulations and perturbation response scanning analysis of the Hsp90 structures to characterize functional role of PTM sites in allosteric regulation. The results reveal a small group of conserved PTMs …