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Chemistry Faculty Publications

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Articles 391 - 420 of 1129

Full-Text Articles in Chemistry

Multi-Dimensional Glycan Microarrays With Glyco-Macroligands, Satya Nandana Narla, Huan Nie, Yu Li, Xue-Long Sun Oct 2015

Multi-Dimensional Glycan Microarrays With Glyco-Macroligands, Satya Nandana Narla, Huan Nie, Yu Li, Xue-Long Sun

Chemistry Faculty Publications

Glycan microarray has become a powerful high-throughput tool for examining binding interactions of carbohydrates with the carbohydrate binding biomolecules like proteins, enzymes, antibodies etc. It has shown great potential for biomedical research and applications, such as antibody detection and profiling, vaccine development, biomarker discovery, and drug screening. Most glycan microarrays were made with monovalent glycans immobilized directly onto the array surface via either covalent or non-covalent bond, which afford a multivalent glycans in two dimensional (2D) displaying. A variety of glyco-macroligands have been developed to mimic multivalent carbohydrate-protein interactions for studying carbohydrate-protein interactions and biomedical research and applications. Recently, a …

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Electron Transfer During Metal-Assisted And Stain Etching Of Silicon, Kurt W. Kolasinski Oct 2015

Electron Transfer During Metal-Assisted And Stain Etching Of Silicon, Kurt W. Kolasinski

Chemistry Faculty Publications

The etching of silicon in fluoride solutions is limited by the kinetics of charge transfer not thermodynamics. This characteristic is what gives fluoride etching its great versatility in making different types of nanostructures as the result of self-limiting chemistry. This review approaches the kinetics of electron transfer from silicon and metal coated silicon to a solution phase species from a fundamental point of view in order to establish a better understanding of the mechanisms of nanostructure formation during metal assisted and stain etching of silicon. Band bending calculations demonstrate that diffusion of holes away from low work function metals such …

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Comparison Crystal Structure Conformations Of Two Structurally Related Biphenyl Analogues: 4,4'-Bis[3-(Pyrrolidin-1-Yl)Prop-1-Yn-1-Yl]-1,1'-Biphenyl And 4,4'-Bis{3-[(S)-2-Methylpyrrolidin-1-Yl]Prop-1-Yn-1-Yl}-1,1'-Biphenyl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks Oct 2015

Comparison Crystal Structure Conformations Of Two Structurally Related Biphenyl Analogues: 4,4'-Bis[3-(Pyrrolidin-1-Yl)Prop-1-Yn-1-Yl]-1,1'-Biphenyl And 4,4'-Bis{3-[(S)-2-Methylpyrrolidin-1-Yl]Prop-1-Yn-1-Yl}-1,1'-Biphenyl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

The title compounds, C26H28N2, (I), and C28H32N2, (II), were designed based on the structure of the potent 910 nicotinic acetyl­choline receptor antagonist ZZ161C {1,1'-[[1,1'-biphen­yl]-4,4'-diylbis(prop-2-yne-3,1-di­yl)]bis­(3,4-di­methyl­pyridin-1-ium) bromide}. In order to improve the druglikeness properties of ZZ161C for potential oral administration, the title compounds (I) and (II) were prepared by coupling 4,4'-bis­(3-bromo­prop-1-yn-1-yl)-1,1'-biphenyl with pyrrol­idine, (I), and (S)-2-methyl­pyrrolidine, (II), respectively, in aceto­nitrile at room temperature. The asymmetric unit of (I) contains two half mol­ecules that each sit on sites of crystallographic inversion. As a result, the biphenyl ring systems in …

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Comparison Of The Crystal Structures Of 4,4′-Bis­­[3-(4-Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Bi­Phenyl And 4,4′-Bis­­[3-(2,2,6,6-Tetra­Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Biphen­Yl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks Oct 2015

Comparison Of The Crystal Structures Of 4,4′-Bis­­[3-(4-Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Bi­Phenyl And 4,4′-Bis­­[3-(2,2,6,6-Tetra­Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Biphen­Yl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

As part of a comprehensive program to discover α9α10 nicotinic acetyl­choline receptor antagonists, the title compounds C30H36N2, (I), and C36H48N2, (II), were synthesized by coupling 4,4′-bis­(3-bromo­prop-1-yn-1-yl)-1,1′-biphenyl with 4-methyl­piperidine and 2,2,6,6-tetra­methyl­piperidine, respectively, in aceto­nitrile at room temperature. In compound (I), the biphenyl system has a twisted conformation with a dihedral angle of 26.57 (6)° between the two phenyl rings of the biphenyl moiety, while in compound (II), the biphenyl moiety sits on a crystallographic inversion centre so the two phenyl rings are exactly coplanar. The terminal piperidine rings in …

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Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman Sep 2015

Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman

Chemistry Faculty Publications

Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air–solid interface under variable relative humidity (RH = 0–90%). The maximum reactive uptake coefficient of O3(g) by catechol γO3 = (7.49 ± 0.35) × 10–6 occurs for …

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Effects Of Interferons And Double-Stranded Rna On Human Prostate Cancer Cell Apoptosis, Haiyan Tan, Chun Zeng, Junbo Xie, Norah J. Alghamdi, Ya Song, Hongbing Zhang, Aimin Zhou, Di Jin Sep 2015

Effects Of Interferons And Double-Stranded Rna On Human Prostate Cancer Cell Apoptosis, Haiyan Tan, Chun Zeng, Junbo Xie, Norah J. Alghamdi, Ya Song, Hongbing Zhang, Aimin Zhou, Di Jin

Chemistry Faculty Publications

Prostate cancer is the second most commonly diagnosed cancer among men in the United States. Prostate cancer therapy is severely hampered by lack of response and development of resistance to conventional chemotherapeutic drugs in patients. Therefore, the development and discovery of new drugs have become an urgent clinical need. Interferons (IFNs), a family of pleiotropic cytokines, exert antitumor activities due to their anti-proliferative, immunomodulatory and proapoptotic functions. Here, we report that pretreatment of prostate cancer PC-3 cells with IFNs sensitized these cells to double-stranded RNAs (dsRNAs)-induced apoptosis. The enhancement effect of IFN treatment was dependent on IFN subtypes, in particular, …

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Localization Length Scales Of Triplet Excitons In Singlet Fission Materials, Sam L. Bayliss, Karl J. Thorley, John E. Anthony, Hélène Bouchiat, Neil C. Greenham, Alexei D. Chepelianskii Sep 2015

Localization Length Scales Of Triplet Excitons In Singlet Fission Materials, Sam L. Bayliss, Karl J. Thorley, John E. Anthony, Hélène Bouchiat, Neil C. Greenham, Alexei D. Chepelianskii

Chemistry Faculty Publications

We measure the dielectric confinement length scales of triplet excitons in organic semiconductors by jointly measuring their microwave-domain electric and magnetic susceptibilities. We apply this technique to characterize triplet excitons in two singlet fission materials with distinct solid-state packing and correlate the extracted localization length scales with the role of the excitonic environment. By using the magnetic susceptibility simultaneously determined through our experiments, we compare the independently extracted dielectric and spin-spin localization length scales, highlighting the role of local anisotropy on the properties of excitonic triplet states.

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Far From 'Easy' Spectroscopy With The 8Π And Griffin Spectrometers At Triumf-Isac, Steven W. Yates, P. E. Garrett, A. J. Radich, J. M. Allmond, C. Andreoiu, G. C. Ball, P. C. Bender, L. Bianco, V. Bildstein, H. Bidaman, R. Braid Sep 2015

Far From 'Easy' Spectroscopy With The 8Π And Griffin Spectrometers At Triumf-Isac, Steven W. Yates, P. E. Garrett, A. J. Radich, J. M. Allmond, C. Andreoiu, G. C. Ball, P. C. Bender, L. Bianco, V. Bildstein, H. Bidaman, R. Braid

Chemistry Faculty Publications

The 8π spectrometer, installed at the TRIUMF-ISAC facility, was the world's most sensitive γ-ray spectrometer dedicated to β-decay studies. A description is given of the 8π spectrometer and its auxiliary detectors including the plastic scintillator array SCEPTAR used for β-particle tagging and the Si(Li) array PACES for conversion electron measurements, its moving tape collector, and its data acquisition system. The recent investigation of the decay of 124Cs to study the nuclear structure of 124Xe, and how the β-decay measurements complemented previous Coulomb excitation studies, is highlighted, including the extraction of the deformation parameters for the excited 0+ …

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Identifying The Tautomeric Form Of A Deoxyguanosine-Estrogen Quinone Intermediate, Douglas E. Stack Sep 2015

Identifying The Tautomeric Form Of A Deoxyguanosine-Estrogen Quinone Intermediate, Douglas E. Stack

Chemistry Faculty Publications

Mechanistic insights into the reaction of an estrogen o-quinone with deoxyguanosine has been further investigated using high level density functional calculations in addition to the use of 4-hyroxycatecholestrone (4-OHE1) regioselectivity labeled with deuterium at the C1-position. Calculations using the M06-2X functional with large basis sets indicate the tautomeric form of an estrogen-DNA adduct present when glycosidic bonds cleavage occurs is comprised of an aromatic A ring structure. This tautomeric form was further verified by use of deuterium labelling of the catechol precursor use to form the estrogen o-quinone. Regioselective deuterium labelling at the C1-position of the estrogen A ring allows …

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Quantitative Analysis Of The Density Of Trap States At The Semiconductor-Dielectric Interface In Organic Field-Effect Transistors, Peter J. Diemer, Zachary A. Lamport, Yaochuan Mei, Jeremy W. Ward, Katelyn P. Goetz, Wei Li, Marcia M. Payne, Martin Guthold, John E. Anthony, Oana D. Jurchescu Sep 2015

Quantitative Analysis Of The Density Of Trap States At The Semiconductor-Dielectric Interface In Organic Field-Effect Transistors, Peter J. Diemer, Zachary A. Lamport, Yaochuan Mei, Jeremy W. Ward, Katelyn P. Goetz, Wei Li, Marcia M. Payne, Martin Guthold, John E. Anthony, Oana D. Jurchescu

Chemistry Faculty Publications

The electrical properties of organic field-effect transistors are governed by the quality of the constituting layers, and the resulting interfaces. We compare the properties of the same organic semiconductor film, 2,8-difluoro- 5,11-bis (triethylsilylethynyl) anthradithiophene, with bottom SiO2 dielectric and top Cytop dielectric and find a 10× increase in charge carrier mobility, from 0.17 ± 0.19 cm2 V−1 s−1 to 1.5 ± 0.70 cm2 V−1 s−1, when the polymer dielectric is used. This results from a significant reduction of the trap density of states in the semiconductor band-gap, and a decrease in the …

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Enzyme Localization, Crowding, And Buffers Collectively Modulate Diffusion-Influenced Signal Transduction: Insights From Continuum Diffusion Modeling, Peter M. Kekenes-Huskey, Changsun Eun, J. A. Mccammon Sep 2015

Enzyme Localization, Crowding, And Buffers Collectively Modulate Diffusion-Influenced Signal Transduction: Insights From Continuum Diffusion Modeling, Peter M. Kekenes-Huskey, Changsun Eun, J. A. Mccammon

Chemistry Faculty Publications

Biochemical reaction networks consisting of coupled enzymes connect substrate signaling events with biological function. Substrates involved in these reactions can be strongly influenced by diffusion “barriers” arising from impenetrable cellular structures and macromolecules, as well as interactions with biomolecules, especially within crowded environments. For diffusion-influenced reactions, the spatial organization of diffusion barriers arising from intracellular structures, non-specific crowders, and specific-binders (buffers) strongly controls the temporal and spatial reaction kinetics. In this study, we use two prototypical biochemical reactions, a Goodwin oscillator, and a reaction with a periodic source/sink term to examine how a diffusion barrier that partitions substrates controls reaction …

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Boron-Rich Benzene And Pyrene Derivatives For The Detection Of Thermal Neutrons, Henok A. Yemam, Adam Mahl, Unsal Koldemir, Tyler Remedes, Sean Parkin, Uwe Greife, Alan Sellinger Sep 2015

Boron-Rich Benzene And Pyrene Derivatives For The Detection Of Thermal Neutrons, Henok A. Yemam, Adam Mahl, Unsal Koldemir, Tyler Remedes, Sean Parkin, Uwe Greife, Alan Sellinger

Chemistry Faculty Publications

A synthetic methodology is developed to generate boron rich aromatic small molecules based on benzene and pyrene moieties for the detection of thermal neutrons. The prepared aromatic compounds have a relatively high boron content up to 7.4 wt%, which is important for application in neutron detection as 10B (20% of natural abundance boron) has a large neutron induced reaction cross-section. This is demonstrated by preparing blends of the synthesized molecules with fluorescent dopants in poly(vinyltoluene) matrices resulting in comparable scintillation light output and neutron capture as state-of-the art commercial scintillators, but with the advantage of much lower cost. The …

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Determination Of Triapine, A Ribonucleotide Reductase Inhibitor, In Human Plasma By Liquid Chromatography Tandem Mass Spectrometry, Ye Feng, Charles A. Kunos, Yan Xu Sep 2015

Determination Of Triapine, A Ribonucleotide Reductase Inhibitor, In Human Plasma By Liquid Chromatography Tandem Mass Spectrometry, Ye Feng, Charles A. Kunos, Yan Xu

Chemistry Faculty Publications

Triapine is an inhibitor of ribonucleotide reductase (RNR). Studies have shown that triapine significantly decreases the activity of RNR and enhanced the radiation-mediated cytotoxicity in cervical and colon cancer. In this work, we have developed and validated a selective and sensitive LC-MS/MS method for the determination of triapine in human plasma. In this method, 2-[(3-fluoro-2-pyridinyl)methylene] hydrazinecarbothioamide (NSC 266749) was used as the internal standard (IS); plasma samples were prepared by deproteinization with acetonitrile; tripaine and the IS were separated on a Waters Xbridge Shield RP18 column (3.5 µm; 2.1 × 50 mm) using a mobile phase containing 25.0% methanol and …

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Globally Profiling Sialylation Status Of Macrophages Upon Statin Treatment, Dan Wang, Huan Nie, Evgeny Ozhegov, Lin Wang, Aimin Zhou, Yu Li, Xue Long Sun Sep 2015

Globally Profiling Sialylation Status Of Macrophages Upon Statin Treatment, Dan Wang, Huan Nie, Evgeny Ozhegov, Lin Wang, Aimin Zhou, Yu Li, Xue Long Sun

Chemistry Faculty Publications

Sialic acids (SAs) are widely expressed on immune cells and their levels and linkages named as sialylation status vary upon cellular environment changes related to both physiological and pathological processes. In this study, we performed a global profiling of the sialylation status of macrophages and their release of SAs in the cell culture medium by using flow cytometry, confocal microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS). Both flow cytometry and confocal microscopy results showed that cell surface α-2,3-linked SAs were predominant in the normal culture condition and changed slightly upon treatment with atorvastatin for 24 h, whereas α-2,6-linked SAs …

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Homo–Lumo Energy Gap Control In Platinum(Ii) Biphenyl Complexes Containing 2,2′-Bipyridine Ligands, D. Paul Rillema, Stanislav R. Stoyanov, Arvin Cruz Ph.D., Huy Nguyen, Curtis Moore, Wei Huang, Khamis Siam, Ali Jehan, Venugopal Komreddy Aug 2015

Homo–Lumo Energy Gap Control In Platinum(Ii) Biphenyl Complexes Containing 2,2′-Bipyridine Ligands, D. Paul Rillema, Stanislav R. Stoyanov, Arvin Cruz Ph.D., Huy Nguyen, Curtis Moore, Wei Huang, Khamis Siam, Ali Jehan, Venugopal Komreddy

Chemistry Faculty Publications

A series of platinum(II) biphenyl 2,2’-bipyridine complexes containing electron-donating and electron-withdrawing moieties on the 4 and 4’ positions of the bipyridine ligand exhibit emission from excited states in the 600 nm region of the spectrum upon excitation in the metal-to-ligand charge transfer transition located near 450 nm. These complexes are distorted from planarity based on both single crystal structure determinations and density functional theory (DFT) calculations of isolated molecules in acetonitrile. The DFT also reveals the geometry of the lowest-lying triplet state (LLTS) of each complex that is important for emission behavior. The LLTS are assigned based on the electron …

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Electrochemical Characterization Of Self-Assembled Monolayers On Gold Substrates Derived From Thermal Decomposition Of Monolayer-Protected Cluster Films, Michael C. Leopold, Tran T. Doan, Melissa J. Mullaney, Andrew F. Loftus, Christopher M. Kidd Aug 2015

Electrochemical Characterization Of Self-Assembled Monolayers On Gold Substrates Derived From Thermal Decomposition Of Monolayer-Protected Cluster Films, Michael C. Leopold, Tran T. Doan, Melissa J. Mullaney, Andrew F. Loftus, Christopher M. Kidd

Chemistry Faculty Publications

Networked films of monolayer-protected clusters (MPCs), alkanethiolate-stabilized gold nanoparticles, can be thermally decomposed to form stable gold on glass substrates that are subsequently modified with self-assembled monolayers (SAMs) for use as modified electrodes. Electrochemical assessment of these SAM-modified gold substrates, including double-layer capacitance measurements, linear sweep desorption of the alkanethiolates, and diffusional redox probing, all show that SAMs formed on gold supports formed from thermolysis of MPC films possess substantially higher defect density compared to SAMs formed on traditional evaporated gold. The density of defects in the SAMs on thermolyzed gold is directly related to the strategies used to assemble …

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Synthesis And Flammability Testing Of Epoxy Functionalized Phosphorous-Based Flame Retardants, Vladimir Benin, Xuemei Cui, Alexander Morgan, Karl Seiwert Aug 2015

Synthesis And Flammability Testing Of Epoxy Functionalized Phosphorous-Based Flame Retardants, Vladimir Benin, Xuemei Cui, Alexander Morgan, Karl Seiwert

Chemistry Faculty Publications

Several potential new phosphorus-containing flame retardant molecules were evaluated for heat release reduction potential by incorporation of the molecules into a polyurethane, generated from methylene diphenyl diisocyanate and 1,3-propane diol. The heat release reduction potential of these substances was evaluated using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods to qualitatively evaluate their potential reactivity into the polyurethane prior to heat release testing. The functionality of the flame retardants was epoxide based that would potentially react with the diol during polyurethane synthesis. Flammability testing …

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Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng Jul 2015

Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng

Chemistry Faculty Publications

The formation of secondary organic aerosol (SOA) from the oxidation of β-pinene via nitrate radicals is investigated in the Georgia Tech Environmental Chamber (GTEC) facility. Aerosol yields are determined for experiments performed under both dry (relative humidity (RH) < 2 %) and humid (RH = 50 % and RH = 70 %) conditions. To probe the effects of peroxy radical (RO2) fate on aerosol formation, "RO2 + NO3 dominant" and "RO2 + HO2 dominant" experiments are performed. Gas-phase organic nitrate species (with molecular weights of 215, 229, 231, and 245 amu, which likely correspond to molecular formulas of C10H17NO4, C10H15NO5, C10H17NO …

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Crystal Structure Of Orthorhombic {Bis-[(Pyridin-2-Yl)Methyl](3,5,5,5-Tetrachloropentyl)Amine-Κ3N,N',N''}Chloridocopper(Ii) Perchlorate, Katherine A. Bussey, Annie R. Cavalier, Jennifer R. Connell, Margaret E. Mraz, Kayode D. Oshin, Tomislav Pintauer, Danielle L. Gray, Sean Parkin Jul 2015

Crystal Structure Of Orthorhombic {Bis-[(Pyridin-2-Yl)Methyl](3,5,5,5-Tetrachloropentyl)Amine-Κ3N,N',N''}Chloridocopper(Ii) Perchlorate, Katherine A. Bussey, Annie R. Cavalier, Jennifer R. Connell, Margaret E. Mraz, Kayode D. Oshin, Tomislav Pintauer, Danielle L. Gray, Sean Parkin

Chemistry Faculty Publications

In the title compound, [CuCl(C17H19Cl4N3)]ClO4, the CuII ion adopts a distorted square-planar geometry defined by one chloride ligand and the three nitro­gen atoms from the bis­[(pyridin-2-yl)meth­yl](3,5,5,5-tetra­chloro­pent­yl)amine ligand. The perchlorate counter-ion is disordered over three sets of sites with refined occupancies 0.0634 (17), 0.221 (16) and 0.145 (7). In addition, the hetero-scorpionate arm of the bis­[(pyridin-2-yl)meth­yl](3,5,5,5-tetra­chloro­pent­yl)amine ligand is disordered over two sets of sites with refined occupancies 0.839 (2) and 0.161 (2). In the crystal, weak Cu⋯Cl inter­actions between symmetry-related mol­ecules create a dimerization with a chloride occupying the apical …

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Low-Voltage Polymer/Small-Molecule Blend Organic Thin-Film Transistors And Circuits Fabricated Via Spray Deposition, Simon Hunter, Jeremy W. Ward, Marcia M. Payne, John E. Anthony, Oana D. Jurchescu, Thomas D. Anthopoulos Jun 2015

Low-Voltage Polymer/Small-Molecule Blend Organic Thin-Film Transistors And Circuits Fabricated Via Spray Deposition, Simon Hunter, Jeremy W. Ward, Marcia M. Payne, John E. Anthony, Oana D. Jurchescu, Thomas D. Anthopoulos

Chemistry Faculty Publications

Organic thin-film electronics have long been considered an enticing candidate in achieving high-throughput manufacturing of low-power ubiquitous electronics. However, to achieve this goal, more work is required to reduce operating voltages and develop suitable mass-manufacture techniques. Here, we demonstrate low-voltage spray-cast organic thin-film transistors based on a semiconductor blend of 2,8-difluoro- 5,11-bis (triethylsilylethynyl) anthradithiophene and poly(triarylamine). Both semiconductor and dielectric films are deposited via successive spray deposition in ambient conditions (air with 40%–60% relative humidity) without any special precautions. Despite the simplicity of the deposition method, p-channel transistors with hole mobilities of >1 cm2/Vs are realized at −4 …

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Dipole Strength Distributions From Higs Experiments, V. Werner, N. Cooper, P. M. Goddard, P. Humby, R. S. Ilieva, G. Rusev, J. Beller, C. Bernards, B. P. Crider, J. Isaak, J. H. Kelley, E. Kwan, B. Löher, E. E. Peters, N. Pietralla, C. Romig, D. Savran, M. Scheck, A. P. Tonchev, W. Tornow, Steven W. Yates, M. Zweidinger May 2015

Dipole Strength Distributions From Higs Experiments, V. Werner, N. Cooper, P. M. Goddard, P. Humby, R. S. Ilieva, G. Rusev, J. Beller, C. Bernards, B. P. Crider, J. Isaak, J. H. Kelley, E. Kwan, B. Löher, E. E. Peters, N. Pietralla, C. Romig, D. Savran, M. Scheck, A. P. Tonchev, W. Tornow, Steven W. Yates, M. Zweidinger

Chemistry Faculty Publications

A series of photon scattering experiments has been performed on the double-beta decay partners 76Ge and 76Se, in order to investigate their dipole response up to the neutron separation threshold. Gamma-ray beams from bremsstrahlung at the S-DALINAC and from Compton-backscattering at HIGS have been used to measure absolute cross sections and parities of dipole excited states, respectively. The HIGS data allows for indirect measurement of averaged branching ratios, which leads to significant corrections in the observed excitation cross sections. Results are compared to statistical calculations, to test photon strength functions and the Axel-Brink hypothesis

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Descant And Β-Delayed Neutron Measurements At Triumf, V. Bildstein, P. E. Garrett, S. F. Ashley, G. C. Ball, L. Bianco, D. Bandyopadhyay, J. Bangay, B. P. Crider, G. Demand, G. Deng, I. Dillman, A. Finlay, A. B. Garnsworthy, G. Hackman, B. Hadinia, R. Krücken, K. G. Leach, J-P. Martin, Marcus T. Mcellistrem, C. J. Pearson, E. E. Peters, Francisco M. Prados-Estévez, A. Radich, F. Sarazin, C. Sumithrarachchi, C. E. Svensson, J. R. Vanhoy, J. Wong, Steven W. Yates May 2015

Descant And Β-Delayed Neutron Measurements At Triumf, V. Bildstein, P. E. Garrett, S. F. Ashley, G. C. Ball, L. Bianco, D. Bandyopadhyay, J. Bangay, B. P. Crider, G. Demand, G. Deng, I. Dillman, A. Finlay, A. B. Garnsworthy, G. Hackman, B. Hadinia, R. Krücken, K. G. Leach, J-P. Martin, Marcus T. Mcellistrem, C. J. Pearson, E. E. Peters, Francisco M. Prados-Estévez, A. Radich, F. Sarazin, C. Sumithrarachchi, C. E. Svensson, J. R. Vanhoy, J. Wong, Steven W. Yates

Chemistry Faculty Publications

The DESCANT array (Deuterated Scintillator Array for Neutron Tagging) consists of up to 70 detectors, each filled with approximately 2 liters of deuterated benzene. This scintillator material o_ers pulse-shape discrimination (PSD) capabilities to distinguish between neutrons and γ-rays interacting with the scintillator material. In addition, the anisotropic nature of n – d scattering allows for the determination of the neutron energy spectrum directly from the pulse height spectrum, complementing the traditional time-of-flight (ToF) information. DESCANT can be coupled either to the TIGRESS (TRIUMF-ISAC Gamma-Ray Escape …

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Inelastic Neutron Scattering Studies Of 76Ge And 76Se: Relevance To Elevance To Neutrinoless Double-Β Decay, B. P. Crider, E. E. Peters, T. J. Ross, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. M. Allmond, J. R. Vanhoy, Steven W. Yates May 2015

Inelastic Neutron Scattering Studies Of 76Ge And 76Se: Relevance To Elevance To Neutrinoless Double-Β Decay, B. P. Crider, E. E. Peters, T. J. Ross, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. M. Allmond, J. R. Vanhoy, Steven W. Yates

Chemistry Faculty Publications

Inelastic neutron scattering measurements were performed at the University of Kentucky Accelerator Laboratory on enriched 76Ge and 76Se scattering samples. From measurements at incident neutron energies from 2.0 to 4.0 MeV, many new levels were identified and characterized in each nucleus; level lifetimes, transition probabilities, multipole mixing ratios, and other properties were determined. In addition, γ-ray cross sections for the 76Ge(n,n′γ) reaction were measured at neutron energies up to 5.0 MeV, with the goal of determining the cross sections of γ rays in 2040-keV region, which corresponds to the region of interest in the neutrinoless double β …

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Inelastic Neutron Scattering Studies Of 132,134Xe: Elucidating Structure In A Transitional Region And Possible Interferences For 0vββ Searches, E. E. Peters, T. J. Ross, B. P. Crider, S. F. Ashley, Anagha Chakraborty, M. D. Hennek, Ajay Kumar, S. H. Liu, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. S. Thrasher, Steven W. Yates May 2015

Inelastic Neutron Scattering Studies Of 132,134Xe: Elucidating Structure In A Transitional Region And Possible Interferences For 0vββ Searches, E. E. Peters, T. J. Ross, B. P. Crider, S. F. Ashley, Anagha Chakraborty, M. D. Hennek, Ajay Kumar, S. H. Liu, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. S. Thrasher, Steven W. Yates

Chemistry Faculty Publications

Highly enriched (> 99.9%) 132Xe and 134Xe gases were converted to solid 132XeF2 and 134XeF2 and were used as scattering samples for inelastic neutron scattering measurements at the University of Kentucky Accelerator Laboratory (UKAL). Lifetimes of levels up to 3.5MeV in excitation energy in these xenon isotopes were measured using the Doppler-shift attenuation method, allowing the determination of reduced transition probabilities. Gamma rays corresponding to new transitions and levels have been observed. In particular, tentative new excited 0+ states and associated decays have been examined in an effort to elucidate the structure of …

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“No-Spin” States And Low-Lying Structures In 130Xe And 136Xe, T. J. Ross, E. E. Peters, Anagha Chakraborty, B. P. Crider, Ajay Kumar, S. H. Liu, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. R. Vanhoy, Steven W. Yates May 2015

“No-Spin” States And Low-Lying Structures In 130Xe And 136Xe, T. J. Ross, E. E. Peters, Anagha Chakraborty, B. P. Crider, Ajay Kumar, S. H. Liu, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. R. Vanhoy, Steven W. Yates

Chemistry Faculty Publications

Inelastic neutron scattering on solid 130XeF2 and 136XeF2 targets was utilized to populate excited levels in 130Xe and 136Xe. When calculating nuclear matrix elements vital to the understanding of double-beta decay, it is important to have a clear understanding of the low-lying level structure of both the parent and daughter nucleus. Of particular relevance to double-beta decay searches are the assignments of 0+ states. We show here that in the case of 130Xe there are several discrepancies in the adopted level structure. We found that one previous 0+ candidate level (1590 …

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Studies Of 54,56Fe Neutron Scattering Cross Sections, S. F. Hicks, J. R. Vanhoy, A. J. French, S. L. Henderson, T. J. Howard, R. L. Pecha, Z. C. Santonil, B. P. Crider, S. Liu, Marcus T. Mcellistrem, E. E. Peters, Francisco M. Prados-Estévez, T. J. Ross, Steven W. Yates May 2015

Studies Of 54,56Fe Neutron Scattering Cross Sections, S. F. Hicks, J. R. Vanhoy, A. J. French, S. L. Henderson, T. J. Howard, R. L. Pecha, Z. C. Santonil, B. P. Crider, S. Liu, Marcus T. Mcellistrem, E. E. Peters, Francisco M. Prados-Estévez, T. J. Ross, Steven W. Yates

Chemistry Faculty Publications

Elastic and inelastic neutron scattering differential cross sections and γ-ray production cross sections have been measured on 54,56Fe at several incident energies in the fast neutron region between 1.5 and 4.7 MeV. All measurements were completed at the University of Kentucky Accelerator Laboratory (UKAL) using a 7-MV Model CN Van de Graaff accelerator, along with the neutron production and neutron and γ-ray detection systems located there. The facilities at UKAL allow the investigation of both elastic and inelastic scattering with nearly mono-energetic incident neutrons. Time-of-flight techniques were used to detect the scattered neutrons for the differential cross section measurements. …

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The Neutron Time-Of-Flight Cross Section Program At The University Of Kentucky - Adventures In Analysis Ii, J. R. Vanhoy, S. F. Hicks, B. C. Combs, B. P. Crider, A. J. French, E. A. Garza, S. L. Henderson, T. J. Howard, S. H. Liu, S. Nigam, R. L. Pecha, E. E. Peters, Francisco M. Prados-Estévez, Marcus T. Mcellistrem, B. J. Rice, T. J. Ross, Z. C. Santonil, L. C. Sidwell, J. L. Steves, Steven W. Yates May 2015

The Neutron Time-Of-Flight Cross Section Program At The University Of Kentucky - Adventures In Analysis Ii, J. R. Vanhoy, S. F. Hicks, B. C. Combs, B. P. Crider, A. J. French, E. A. Garza, S. L. Henderson, T. J. Howard, S. H. Liu, S. Nigam, R. L. Pecha, E. E. Peters, Francisco M. Prados-Estévez, Marcus T. Mcellistrem, B. J. Rice, T. J. Ross, Z. C. Santonil, L. C. Sidwell, J. L. Steves, Steven W. Yates

Chemistry Faculty Publications

Elastic and inelastic neutron differential cross sections are measured at the University of Kentucky Accelerator Laboratory (www.pa.uky.edu/accelerator/) at incident energies in the fast neutron region. The laboratorys facilities and instrumentation will be described and our measurement and analysis procedures outlined. Many corrections are required for neutron scattering experiments and the analysis utilizes information from many other cross section data sets and model calculations. Exploring and understanding the limitations of the foundational information and procedures are important for controlling the accuracy of the cross section results. We are examining the limitations in neutron detection efficiency, the normalization of (n,n′ …

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A Review On The Bulk And Surface Chemistry Of Iron In Atmospherically-Relevant Systems Containing Humic Like Substances (Hulis), Hind A. Al-Abadleh May 2015

A Review On The Bulk And Surface Chemistry Of Iron In Atmospherically-Relevant Systems Containing Humic Like Substances (Hulis), Hind A. Al-Abadleh

Chemistry Faculty Publications

As the fourth most abundant element by mass in the Earth’s crust, iron is ubiquitous and its chemistry is rich and interdisciplinary in nature. This review synthesizes the current state of knowledge of iron chemistry in multicomponent atmospheric aerosols, which is also applicable to other atmospherically-relevant systems that include iron-containing anthropogenic nanodust, ocean surfaces and buildings. Because of the abundance of humic-like substances (HULIS) in these systems, studies on their chemistry with iron and those used as models for HULIS are the focus of this review. Findings from field measurements and laboratory studies are summarized to highlight major themes in …

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A Rapid Lc-Ms/Ms Method For Quantification Of Csuoh0901, A Novel Antitumor Agent, In Rat Plasma, Ramakrishna R. Voggu, Ravali Alagandula, Xiang Zhou, Bin Su Ph.D., Bo Zhong, Baochuan Guo May 2015

A Rapid Lc-Ms/Ms Method For Quantification Of Csuoh0901, A Novel Antitumor Agent, In Rat Plasma, Ramakrishna R. Voggu, Ravali Alagandula, Xiang Zhou, Bin Su Ph.D., Bo Zhong, Baochuan Guo

Chemistry Faculty Publications

CSUOH0901, a novel anticancer derivative of nimesulide, exhibits very promising anticancer activities in various cancer cell lines. In order to support further pharmacological and toxicological studies of this promising anticancer drug candidate, an LC-MS/MS method was developed and validated in accordance with the US Food and Drug Administration guidelines. The drug molecules were extracted from plasma samples by protein precipitation and then analyzed with LC-ESI-MS/MS. An excellent analyte separation was achieved using a phenomenex C18 column with a mobile phase of 90% methanol and 5 m m of ammonium formate. The validated linear dynamic range was between 0.5 and 100 …

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A Rapid Lc-Ms/Ms Method For Quantification Of Csuoh0901, A Novel Antitumor Agent, In Rat Plasma, Ramakrishna R. Voggu, Ravali Alagandula, Xiang Zhou, Bin Su, Bo Zhong, Baochuan Guo May 2015

A Rapid Lc-Ms/Ms Method For Quantification Of Csuoh0901, A Novel Antitumor Agent, In Rat Plasma, Ramakrishna R. Voggu, Ravali Alagandula, Xiang Zhou, Bin Su, Bo Zhong, Baochuan Guo

Chemistry Faculty Publications

CSUOH0901, a novel anticancer derivative of nimesulide, exhibits very promising anticancer activities in various cancer cell lines. In order to support further pharmacological and toxicological studies of this promising anticancer drug candidate, an LC-MS/MS method was developed and validated in accordance with the US Food and Drug Administration guidelines. The drug molecules were extracted from plasma samples by protein precipitation and then analyzed with LC-ESI-MS/MS. An excellent analyte separation was achieved using a phenomenex C18 column with a mobile phase of 90% methanol and 5 m m of ammonium formate. The validated linear dynamic range was between 0.5 and 100 …

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