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Full-Text Articles in Physical Sciences and Mathematics
Aerobic C-C And C-O Bond Formation Reactions Mediated By High-Valent Nickel Species., Sofia Smith, Oriol Planas, Laura Gómez, Nigam Rath, Xavi Ribas, Liviu Mirica, Liviu Mirica
Aerobic C-C And C-O Bond Formation Reactions Mediated By High-Valent Nickel Species., Sofia Smith, Oriol Planas, Laura Gómez, Nigam Rath, Xavi Ribas, Liviu Mirica, Liviu Mirica
Chemistry & Biochemistry Faculty Works
Nickel complexes have been widely employed as catalysts in C–C and C–heteroatom bond formation reactions. While Ni(0), Ni(I), and Ni(II) intermediates are most relevant in these transformations, recently Ni(III) and Ni(IV) species have also been proposed to play a role in catalysis. Reported herein is the synthesis, detailed characterization, and reactivity of a series of Ni(II) and Ni(III) metallacycle complexes stabilized by tetradentate pyridinophane ligands with various N-substituents. Interestingly, while the oxidation of the Ni(II) complexes with various other oxidants led to exclusive C–C bond formation in very good yields, the use of O2 or H2O2 as oxidants led to …
The Chemistry And Biology Of Cyclophostin, The Cyclipostins And Related Compounds, Christopher Spilling
The Chemistry And Biology Of Cyclophostin, The Cyclipostins And Related Compounds, Christopher Spilling
Chemistry & Biochemistry Faculty Works
Cyclophostin, the cyclipostins and the salinipostins are structurally related cyclic enolphosphate natural products. This mini review describes their isolation, synthesis and biological activities. In addition, the synthesis and biological activities of monocyclic enolphosphate and mono and bicyclic enolphosphonate analogs are presented.
Biosensor Applications Of Electrodeposited Nanostructures, Keith Stine
Biosensor Applications Of Electrodeposited Nanostructures, Keith Stine
Chemistry & Biochemistry Faculty Works
The development of biosensors for a range of analytes from small molecules to proteins to oligonucleotides is an intensely active field. Detection methods based on electrochemistry or on localized surface plasmon responses have advanced through using nanostructured electrodes prepared by electrodeposition, which is capable of preparing a wide range of different structures. Supported nanoparticles can be prepared by electrodeposition through applying fixed potentials, cycling potentials, and fixed current methods. Nanoparticle sizes, shapes, and surface densities can be controlled, and regular structures can be prepared by electrodeposition through templates. The incorporation of multiple nanomaterials into composite films can take advantage of …
Synthetic Ionophores As Non-Resistant Antibiotic Adjuvants, George Gokel, Mohit Patel, Evan Garrad, Joseph Meisel, Saeedeh Negin, Michael Gokel
Synthetic Ionophores As Non-Resistant Antibiotic Adjuvants, George Gokel, Mohit Patel, Evan Garrad, Joseph Meisel, Saeedeh Negin, Michael Gokel
Chemistry & Biochemistry Faculty Works
Antimicrobial resistance is a world-wide health care crisis. New antimicrobials must both exhibit potency and thwart the ability of bacteria to develop resistance to them. We report the use of synthetic ionophores as a new approach to developing non-resistant antimicrobials and adjuvants. Most studies involving amphiphilic antimicrobials have focused on either developing synthetic amphiphiles that show ion transport, or developing non-cytotoxic analogs of such peptidic amphiphiles as colistin. We have rationally designed, prepared, and evaluated crown ether-based synthetic ionophores (‘hydraphiles’) that show selective ion transport through bilayer membranes and are toxic to bacteria. We report here that hydraphiles exhibit a …
Lipg A Bifunctional Phospholipase/Thioesterase Involved In Mycobacterial Envelope Remodeling, Christopher Spilling, Pierre Santucci, Vanessa Point, Isabelle Poncin, Alexandre Guy, Celine Crauste, Carole Serveau-Avesque, Jean Galano, Jean-Francois Cavalier, Stephane Canaan
Lipg A Bifunctional Phospholipase/Thioesterase Involved In Mycobacterial Envelope Remodeling, Christopher Spilling, Pierre Santucci, Vanessa Point, Isabelle Poncin, Alexandre Guy, Celine Crauste, Carole Serveau-Avesque, Jean Galano, Jean-Francois Cavalier, Stephane Canaan
Chemistry & Biochemistry Faculty Works
Tuberculosis caused by Mycobacterium tuberculosis is currently one of the leading causes of death from an infectious agent. The main difficulties encountered in eradicating this bacteria are mainly related to (i) a very complex lipid composition of the bacillus cell wall, (ii) its ability to hide from the immune system inside the granulomas, and (iii) the increasing number of resistant strains. In this context, we were interested in the Rv0646c (lipGMTB) gene located upstream to the mmaA cluster which is described as being crucial for the production of cell wall components and required for the bacilli adaptation and survival in …
Generating High-Order Optical And Spin Harmonics From Ferromagnetic Monolayers, G.P. Zhang, M.S. Si, M. Murakami, Y.H. Bai, Thomas George
Generating High-Order Optical And Spin Harmonics From Ferromagnetic Monolayers, G.P. Zhang, M.S. Si, M. Murakami, Y.H. Bai, Thomas George
Chemistry & Biochemistry Faculty Works
High-order harmonic generation (HHG) in solids has entered a new phase of intensive research, with envisioned band-structure mapping on an ultrashort time scale. This partly benefits from a flurry of new HHG materials discovered, but so far has missed an important group. HHG in magnetic materials should have profound impact on future magnetic storage technology advances. Here we introduce and demonstrate HHG in ferromagnetic monolayers. We find that HHG carries spin information and sensitively depends on the relativistic spin–orbit coupling; and if they are dispersed into the crystal momentum k space, harmonics originating from real transitions can be k-resolved and …
Bis(Triphenylphosphine) Iminium Tetrafluoroborate Chloroform Monosolvate, Rachana Manandhar, Nigam Rath, Myron Jones
Bis(Triphenylphosphine) Iminium Tetrafluoroborate Chloroform Monosolvate, Rachana Manandhar, Nigam Rath, Myron Jones
Chemistry & Biochemistry Faculty Works
In the title compound, C36H30NP2+·BF4−·CHCl3 or [PPN]BF4·CHCl3, where [PPN] = [(Ph3P)2N]+, two triphenylphosphine units are attached to a central N atom. The P—N—P bond angle is 137.69 (11)°. The two P—N bonds are nearly equivalent, with lengths of 1.5834 (18) and 1.5798 (17) Å. Both the BF4− anion and the chloroform solvent molecule are disordered over two positions, with occupancy ratios of 0.872 (3):0.128 (3) and 0.9628 (9):0.0372 (9), respectively. In the crystal, C—H⋯F and C—H⋯Cl hydrogen bonds link the [PPN]+ cations, the BF4− anions, and the chloroform solvent molecules into an array which extends along the b-axis direction.
Crystal Structures Of 2-Bromo-1,1,1,3,3,3-HexaMethyl-2-(TriMethylSilYl)TrisIlane And 2-Bromo-1,1,1,3,3,3-HexaIsopropyl-2-(TriisoPropylSilYl)TriSilane, Eva Gulotty, Richard Staples, Shannon Biros, Peter Gaspar, Nigam Rath, William Winchester
Crystal Structures Of 2-Bromo-1,1,1,3,3,3-HexaMethyl-2-(TriMethylSilYl)TrisIlane And 2-Bromo-1,1,1,3,3,3-HexaIsopropyl-2-(TriisoPropylSilYl)TriSilane, Eva Gulotty, Richard Staples, Shannon Biros, Peter Gaspar, Nigam Rath, William Winchester
Chemistry & Biochemistry Faculty Works
The synthesis and crystal structures of two tris(trialkylsilyl)silyl bromide compounds, C9H27BrSi4 (I, HypSiBr) and C27H63BrSi4 (II, TipSiBr), are described. Compound I was prepared in 85% yield by free-radical bromination of 1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane using bromobutane and 2,2′-azobis(2-methylpropionitrile) as a radical initiator at 333 K. The molecule possesses threefold rotational symmetry, with the central Si atom and the Br atom being located on the threefold rotation axis. The Si—Br bond distance is 2.2990 (12) Å and the Si—Si bond lengths are 2.3477 (8) Å. The Br—Si—Si bond angles are 104.83 (3)° and the Si—Si—Si bond angles are 113.69 (2)°, reflecting the steric hindrance …
Conjugation Of Nanomaterials And Nematic Liquid Crystals For Futuristic Applications And Biosensors, Thomas George, Amit Choudhary, Guoqiang Li
Conjugation Of Nanomaterials And Nematic Liquid Crystals For Futuristic Applications And Biosensors, Thomas George, Amit Choudhary, Guoqiang Li
Chemistry & Biochemistry Faculty Works
The established role of nematic liquid crystals (NLCs) in the recent rapid development of displays has motivated researchers to modulate the electro-optical properties of LCs. Furthermore, adding nanomaterials into NLCs has led to enhancements of the properties of NLCs, like reduced threshold of the operating voltage, variation in pretilt angle, reduced switching time, etc. These enhanced properties, due to interfacial dynamics, are enabling wider applications of NLCs and nanomaterials. The recent literature of nanomaterial-doped NLCs is rich with various kinds of nanomaterials in a variety of NLCs. The light has been focused on the most widely used and studied gold …
The Spin-Forbidden A^4z-—X^2n(1/2) Transition Of Geh Detected In Absorption Using Intracavity Laser Spectroscopy, James O'Brien, L. O'Brien, L. Harms
The Spin-Forbidden A^4z-—X^2n(1/2) Transition Of Geh Detected In Absorption Using Intracavity Laser Spectroscopy, James O'Brien, L. O'Brien, L. Harms
Chemistry & Biochemistry Faculty Works
The a 4Σ--X 2Π1/2 transition of GeH has been recorded in absorption for the first time using Intracavity Laser Spectroscopy (ILS). The GeH molecules were produced in a 0.40-0.60 A DC plasma discharge inside an aluminum hollow cathode, using 500 mTorr of Ar, 100 mTorr of H2, and 200 mTorr of GeH4. This cathode is located within the resonator cavity of a Coherent Verdi™ V-10 pumped dye laser. Effective path lengths for this series of measurements using the ILS method ranged from 2 to 7 km. Spectra were calibrated using the absorption spectrum of I2 collected from an extracavity cell, …
Shaping Light In Backward-Wave Nonlinear Hyperbolic Metamaterials, Thomas George, Alexander Popov, Sergey Myslivets, Vitaly Slabko, Victor Tkachenko
Shaping Light In Backward-Wave Nonlinear Hyperbolic Metamaterials, Thomas George, Alexander Popov, Sergey Myslivets, Vitaly Slabko, Victor Tkachenko
Chemistry & Biochemistry Faculty Works
Backward electromagnetic waves are extraordinary waves with contra-directed phase velocity and energy flux. Unusual properties of the coherent nonlinear optical coupling of the phase-matched ordinary and backward electromagnetic waves with contra-directed energy fluxes are described that enable greatly-enhanced frequency and propagation direction conversion, parametrical amplification, as well as control of shape of the light pulses. Extraordinary transient processes that emerge in such metamaterials in pulsed regimes are described. The results of the numerical simulation of particular plasmonic metamaterials with hyperbolic dispersion are presented, which prove the possibility to match phases of such coupled guided ordinary and backward electromagnetic waves. Particular …
Preparation, Modification, Characterization, And Biosensing Application Of Nanoporous Gold Using Electrochemical Techniques, Jay Bhattarai, Dharmendra Neupane, Bishal Nepal, Vasilii Mikhaylov, Alexei Demchenko, Keith Stine
Preparation, Modification, Characterization, And Biosensing Application Of Nanoporous Gold Using Electrochemical Techniques, Jay Bhattarai, Dharmendra Neupane, Bishal Nepal, Vasilii Mikhaylov, Alexei Demchenko, Keith Stine
Chemistry & Biochemistry Faculty Works
Nanoporous gold (np-Au), because of its high surface area-to-volume ratio, excellent conductivity, chemical inertness, physical stability, biocompatibility, easily tunable pores, and plasmonic properties, has attracted much interested in the field of nanotechnology. It has promising applications in the fields of catalysis, bio/chemical sensing, drug delivery, biomolecules separation and purification, fuel cell development, surface-chemistry-driven actuation, and supercapacitor design. Many chemical and electrochemical procedures are known for the preparation of np-Au. Recently, researchers are focusing on easier and controlled ways to tune the pores and ligaments size of np-Au for its use in different applications. Electrochemical methods have good control over fine-tuning …
Ruthenium Complexes Of The General Formula [Rucl 2 (Phox) 2 ] As Precatalysts In Propargylic Substitution Reactions, Negar Jourabchian, Kellsie Jurkowski, Eike Bauer
Ruthenium Complexes Of The General Formula [Rucl 2 (Phox) 2 ] As Precatalysts In Propargylic Substitution Reactions, Negar Jourabchian, Kellsie Jurkowski, Eike Bauer
Chemistry & Biochemistry Faculty Works
After activation by chloride abstraction utilizing NaBArF as an activator (BArF = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate), a complex of the general formula [RuCl2 (PHOX)2 ] was utilized as a catalyst in propargylic substitution reactions, where PHOX is a phosphinooxazoline ligand. Oxygen and nitrogen-centered nucleophiles could be employed in the substitution of a propargylic acetate to obtain the corresponding propargylic substitution products in 87% to 9% isolated yields (45 °C, 16 h reaction time, toluene solvent, 1-2 mol% catalyst loading, 1-2 mol% activator).
Identification Of 4-Isopropyl–Thiotropolone As A Novel Anti-Microbial: Regioselective Synthesis, Nmr Characterization, And Biological Evaluation, Mohamed Elagawany, Mohamed Elagawany, Lamees Hegazy, Feng Cao, Maureen Donlin, Nigam Rath, John Tavis, Bahaa Elgendy, Bahaa Elgendy
Identification Of 4-Isopropyl–Thiotropolone As A Novel Anti-Microbial: Regioselective Synthesis, Nmr Characterization, And Biological Evaluation, Mohamed Elagawany, Mohamed Elagawany, Lamees Hegazy, Feng Cao, Maureen Donlin, Nigam Rath, John Tavis, Bahaa Elgendy, Bahaa Elgendy
Chemistry & Biochemistry Faculty Works
We have synthesized and separated tosylated thujaplicin isomers for the first time, and elucidated their structures using 1D, 2D-NMR techniques and X-ray crystallography. The tosylated isomers were used to synthesize 4-isopropyl–thiotropolone and 6-isopropyl–thiotropolone in a regioselective manner. 1H and 13C Chemical shifts of synthesized isomers were fully assigned using several NMR experiments, and their isotropic magnetic shielding was calculated using the GIAO (Gauge Including Atomic Orbitals) method and the B3LYP def2-TZVPP level of theory. The calculated chemical shift values were in a good agreement with the experimental results. The biological activity of all synthesized compounds was evaluated against the fungal …
First-Principles And Model Simulation Of All-Optical Spin Reversal, Thomas George, G.P. Zhang, Z. Babyak, Y. Xue, Y. Bai
First-Principles And Model Simulation Of All-Optical Spin Reversal, Thomas George, G.P. Zhang, Z. Babyak, Y. Xue, Y. Bai
Chemistry & Biochemistry Faculty Works
All-optical spin switching is a potential trailblazer for information storage and communication at an unprecedented fast rate free of magnetic fields. However, the current wisdom is largely based on semiempirical models of effective magnetic fields and heat pulses, so it is difficult to provide high-speed design protocols for actual devices. Here, we carry out a massively parallel first-principles and model calculation for 13 spin systems and magnetic layers, free of any effective field, to establish a simpler and alternative paradigm of laser-induced ultrafast spin reversal and to point out a path to a full-integrated photospintronic device. It is the interplay …
Intramolecular Glycosylation, Alexei Demchenko, Xiao Jia
Intramolecular Glycosylation, Alexei Demchenko, Xiao Jia
Chemistry & Biochemistry Faculty Works
Carbohydrate oligomers remain challenging targets for chemists due to the requirement for elaborate protecting and leaving group manipulations, functionalization, tedious purification, and sophisticated characterization. Achieving high stereocontrol in glycosylation reactions is arguably the major hurdle that chemists experience. This review article overviews methods for intramolecular glycosylation reactions wherein the facial stereoselectivity is achieved by tethering of the glycosyl donor and acceptor counterparts.
Biophysical And Computational Studies Of The Vcci:Vmip-Ii Complex, Anna Nguyen, Nai-Wei Kuo, Laura Showalter, Ricardo Ramos, Cynthia Dupureur, Michael Colvin, Patricia Liwang
Biophysical And Computational Studies Of The Vcci:Vmip-Ii Complex, Anna Nguyen, Nai-Wei Kuo, Laura Showalter, Ricardo Ramos, Cynthia Dupureur, Michael Colvin, Patricia Liwang
Chemistry & Biochemistry Faculty Works
Certain viruses have the ability to subvert the mammalian immune response, including interference in the chemokine system. Poxviruses produce the chemokine binding protein vCCI (viral CC chemokine inhibitor; also called 35K), which tightly binds to CC chemokines. To facilitate the study of vCCI, we first provide a protocol to produce folded vCCI from Escherichia coli (E. coli.) It is shown here that vCCI binds with unusually high affinity to viral Macrophage Inflammatory Protein-II (vMIP-II), a chemokine analog produced by the virus, human herpesvirus 8 (HHV-8). Fluorescence anisotropy was used to investigate the vCCI:vMIP-II complex and shows that vCCI binds to …
Cyclipostins And Cyclophostin Analogs As Promising Compounds In The Fight Against Tuberculosis, Phuong Nguyen, Vincent Delorme, Anaïs Bénarouche, Benjamin Martin, Rishi Paudel, Giri Gnawali, Abdeldjalil Madani, Rémy Puppo, Valérie Landry, Laurent Kremer, Priscille Brodin, Christopher Spilling, Jean-François Cavalier, Stéphane Canaan
Cyclipostins And Cyclophostin Analogs As Promising Compounds In The Fight Against Tuberculosis, Phuong Nguyen, Vincent Delorme, Anaïs Bénarouche, Benjamin Martin, Rishi Paudel, Giri Gnawali, Abdeldjalil Madani, Rémy Puppo, Valérie Landry, Laurent Kremer, Priscille Brodin, Christopher Spilling, Jean-François Cavalier, Stéphane Canaan
Chemistry & Biochemistry Faculty Works
A new class of Cyclophostin and Cyclipostins (CyC) analogs have been investigated against Mycobacterium tuberculosis H37Rv (M. tb) grown either in broth medium or inside macrophages. Our compounds displayed a diversity of action by acting either on extracellular M. tb bacterial growth only, or both intracellularly on infected macrophages as well as extracellularly on bacterial growth with very low toxicity towards host macrophages. Among the eight potential CyCs identified, CyC 17 exhibited the best extracellular antitubercular activity (MIC50 = 500 nM). This compound was selected and further used in a competitive labelling/enrichment assay against the activity-based probe Desthiobiotin-FP in order …
Characterization Of Wy 14,643 And Its Complex With Aldose Reductase, Michael Sawaya, Malkhey Verma, Vaishnavi Balendiran, Nigam Rath, Duilio Cascio, Ganesaratnam Balendiran
Characterization Of Wy 14,643 And Its Complex With Aldose Reductase, Michael Sawaya, Malkhey Verma, Vaishnavi Balendiran, Nigam Rath, Duilio Cascio, Ganesaratnam Balendiran
Chemistry & Biochemistry Faculty Works
The peroxisome proliferator, WY 14,643 exhibits a pure non-competitive inhibition pattern in the aldehyde reduction and in alcohol oxidation activities of human Aldose reductase (hAR). Fluorescence emission measurements of the equilibrium dissociation constants, Kd, of oxidized (hAR•NADP+) and reduced (hAR•NADPH) holoenzyme complexes display a 2-fold difference between them. Kd values for the dissociation of WY 14,643 from the oxidized (hAR•NADP+•WY 14,643) and reduced (hAR•NADPH•WY 14,643) ternary complexes are comparable to each other. The ternary complex structure of hAR•NADP+•WY 14,643 reveals the first structural evidence of a fibrate class drug binding to hAR. These observations demonstrate how fibrate molecules such as …
Conformationally Superarmed S-Ethyl Glycosyl Donors As Effective Building Blocks For Chemoselective Oligosaccharide Synthesis In One Pot, Mithila Bandara, Jagodige Yasomanee, Nigam Rath, Christian Pedersen, Mikael Bols, Alexei Demchenko
Conformationally Superarmed S-Ethyl Glycosyl Donors As Effective Building Blocks For Chemoselective Oligosaccharide Synthesis In One Pot, Mithila Bandara, Jagodige Yasomanee, Nigam Rath, Christian Pedersen, Mikael Bols, Alexei Demchenko
Chemistry & Biochemistry Faculty Works
A new series of superarmed glycosyl donors has been investigated. It was demonstrated that the S-ethyl leaving group allows for high reactivity, which is much higher than that of equally equipped S-phenyl glycosyl donors that were previously investigated by our groups. The superarmed S-ethyl glycosyl donors equipped with a 2-O-benzoyl group gave complete β-stereoselectivity. Utility of the new glycosyl donors has been demonstrated in a one-pot one-addition oligosaccharide synthesis with all of the reaction components present from the beginning.
Fluselenamyl: A Novel Benzoselenazole Derivative For Pet Detection Of Amyloid Plaques (Aβ) In Alzheimer's Disease, Nigam Rath, G.S.M. Sundaram, Dhruva Dhavale, Julie Prior, Ping Yan, John Cirrito, Richard Laforest, Nigel Cairns, Jin-Moo Lee, Paul Kotzbauer, Vijay Sharma
Fluselenamyl: A Novel Benzoselenazole Derivative For Pet Detection Of Amyloid Plaques (Aβ) In Alzheimer's Disease, Nigam Rath, G.S.M. Sundaram, Dhruva Dhavale, Julie Prior, Ping Yan, John Cirrito, Richard Laforest, Nigel Cairns, Jin-Moo Lee, Paul Kotzbauer, Vijay Sharma
Chemistry & Biochemistry Faculty Works
Fluselenamyl (5), a novel planar benzoselenazole shows traits desirable of enabling noninvasive imaging of Aβ pathophysiology in vivo; labeling of both diffuse (an earlier manifestation of neuritic plaques) and fibrillar plaques in Alzheimer’s disease (AD) brain sections, and remarkable specificity for mapping Aβ compared with biomarker proteins of other neurodegenerative diseases. Employing AD homogenates, [18F]-9, a PET tracer demonstrates superior (2–10 fold higher) binding affinity than approved FDA tracers, while also indicating binding to high affinity site on Aβ plaques. Pharmacokinetic studies indicate high initial influx of [18F]-9 in normal mice brains accompanied by rapid clearance in the absence of …
A Simplified Direct Lipid Mixing Lipoplex Preparation: Comparison Of Liposomal-, Dimethylsulfoxide-, And Ethanol-Based Methods, Joseph Meisel, George Gokel
A Simplified Direct Lipid Mixing Lipoplex Preparation: Comparison Of Liposomal-, Dimethylsulfoxide-, And Ethanol-Based Methods, Joseph Meisel, George Gokel
Chemistry & Biochemistry Faculty Works
Established transfection methodology often uses commercial reagents, which must be formed into liposomes in a sequence of about half a dozen steps. The simplified method reported here is a direct lipid mixing approach that requires fewer steps, less manipulation, and is less time-consuming. Results are comparable to those obtained with more commonly used methods, as judged by a variety of analytical techniques and by comparisons of transfection results. The method reported here may be applied to non-liposome-forming compounds, thereby greatly expanding the range of structures that can be tested for transfection ability.
App Regulates Microglial Phenotype In A Mouse Model Of Alzheimer's Disease, Gunjan Manocha, Angela Floden, Keiko Rausch, Joshua Kulas, Brett Mcgregor, Lalida Rojanathammanee, Kelley Puig, Kendra Puig, Sanjib Karki, Michael Nichols, Diane Darland, James Porter, Colin Combs
App Regulates Microglial Phenotype In A Mouse Model Of Alzheimer's Disease, Gunjan Manocha, Angela Floden, Keiko Rausch, Joshua Kulas, Brett Mcgregor, Lalida Rojanathammanee, Kelley Puig, Kendra Puig, Sanjib Karki, Michael Nichols, Diane Darland, James Porter, Colin Combs
Chemistry & Biochemistry Faculty Works
Prior work suggests that amyloid precursor protein (APP) can function as a proinflammatory receptor on immune cells, such as monocytes and microglia. Therefore, we hypothesized that APP serves this function in microglia during Alzheimer's disease. Although fibrillar amyloid β (Aβ)-stimulated cytokine secretion from both wild-type and APP knock-out (mAPP−/−) microglial cultures, oligomeric Aβ was unable to stimulate increased secretion from mAPP−/− cells. This was consistent with an ability of oligomeric Aβ to bind APP. Similarly, intracerebroventricular infusions of oligomeric Aβ produced less microgliosis in mAPP−/− mice compared with wild-type mice. The mAPP−/− mice crossed to an APP/PS1 transgenic mouse line …
Uplc–Qtof–Ms And Nmr Analyses Of Graviola (Annona Muricata) Leaves, Ingrid De Moraes, Paulo Ribeiro, Flávio Schmidt, Kirley Canuto, Guilherme Zocolo, Edy De Brito, Rensheng Luo, Kristy Richards, Kevin Tran, Robert Smith
Uplc–Qtof–Ms And Nmr Analyses Of Graviola (Annona Muricata) Leaves, Ingrid De Moraes, Paulo Ribeiro, Flávio Schmidt, Kirley Canuto, Guilherme Zocolo, Edy De Brito, Rensheng Luo, Kristy Richards, Kevin Tran, Robert Smith
Chemistry & Biochemistry Faculty Works
No abstract provided.
Variable Van Der Waals Radii Derived From A Hybrid Gaussian Charge Distribution Model For Continuum-Solvent Electrostatic Calculations, Renlong Ye, Xuemei Nie, Chung Wong, Xuedong Gong, Yan Wang, Thomas Heine, Baojing Zhou
Variable Van Der Waals Radii Derived From A Hybrid Gaussian Charge Distribution Model For Continuum-Solvent Electrostatic Calculations, Renlong Ye, Xuemei Nie, Chung Wong, Xuedong Gong, Yan Wang, Thomas Heine, Baojing Zhou
Chemistry & Biochemistry Faculty Works
We introduce a hybrid Gaussian charge distribution model (HGM) that partitions the molecular electron density into overlapping spherical atomic domains. The semi-empirical HGM consists of atom-centered spherical Gaussian functions and discrete point charges, which are optimized to reproduce the electrostatic potential on the molecular surface as well as the number of electrons in atom-centered and certain off-atom-centered spherical regions as closely as possible. In contrast, our previous Gaussian charge distribution model [J. Chem. Phys. 129, 014509 (2008)] contained only spherical Gaussian functions and was not required to reproduce the number of electrons in off-atom-centered regions. Variable van der Waals (vdW) …
Phase Transition Enthalpy Measurements Of Organic And Organometallic Compounds. Sublimation, Vaporization And Fusion Enthalpies From 1880 To 2015. Part 1. C1 − C10, William Acree, James Chickos
Phase Transition Enthalpy Measurements Of Organic And Organometallic Compounds. Sublimation, Vaporization And Fusion Enthalpies From 1880 To 2015. Part 1. C1 − C10, William Acree, James Chickos
Chemistry & Biochemistry Faculty Works
A compendium of phase change enthalpies published in 2010 is updated to include the period 1880–2015. Phase change enthalpies including fusion, vaporization, and sublimation enthalpies are included for organic, organometallic, and a few inorganic compounds. Part 1 of this compendium includes organic compounds from C1 to C10. Part 2 of this compendium, to be published separately, will include organic and organometallic compounds from C11 to C192. Sufficient data are presently available to permit thermodynamic cycles to be constructed as an independent means of evaluating the reliability of the data. Temperature adjustments of phase change enthalpies from the temperature of measurement …
Heterogeneous Dynamics In Dna Site Discrimination By The Structurally Homologous Dna-Binding Domains Of Ets-Family Transcription Factors, Gaofei He, Ana Tolic, James Bashkin, Gregory Poon
Heterogeneous Dynamics In Dna Site Discrimination By The Structurally Homologous Dna-Binding Domains Of Ets-Family Transcription Factors, Gaofei He, Ana Tolic, James Bashkin, Gregory Poon
Chemistry & Biochemistry Faculty Works
The ETS family of transcription factors exemplifies current uncertainty in how eukaryotic genetic regulators with overlapping DNA sequence preferences achieve target site specificity. PU.1 and Ets-1 represent archetypes for studying site discrimination by ETS proteins because their DNA-binding domains are the most divergent in sequence, yet they share remarkably superimposable DNA-bound structures. To gain insight into the contrasting thermodynamics and kinetics of DNA recognition by these two proteins, we investigated the structure and dynamics of site discrimination by their DNA-binding domains. Electrophoretic mobilities of complexes formed by the two homologs with circularly permuted binding sites showed significant dynamic differences only …
Stereocontrolled 1,2-Cis Glycosylation As The Driving Force Of Progress In Synthetic Carbohydrate Chemistry, Swati Nigudkar, Alexei Demchenko
Stereocontrolled 1,2-Cis Glycosylation As The Driving Force Of Progress In Synthetic Carbohydrate Chemistry, Swati Nigudkar, Alexei Demchenko
Chemistry & Biochemistry Faculty Works
Recent developments in stereoselective 1,2-cis glycosylation that have emerged during the past decade are surveyed herein. For detailed coverage of the previous achievements in the field the reader is referred to our earlier reviews: A. V. Demchenko, Curr. Org. Chem., 2003, 7, 35–79 and Synlett, 2003, 1225–1240.
A Generator-Produced Gallium-68 Radiopharmaceutical For Pet Imaging Of Myocardial Perfusion, Nigam Rath, Vijay Sharma, Jothilingam Sivapackiam, Scott Harpstrite, Julie Prior, Hannah Gu, David Piwnica-Worms
A Generator-Produced Gallium-68 Radiopharmaceutical For Pet Imaging Of Myocardial Perfusion, Nigam Rath, Vijay Sharma, Jothilingam Sivapackiam, Scott Harpstrite, Julie Prior, Hannah Gu, David Piwnica-Worms
Chemistry & Biochemistry Faculty Works
Lipophilic cationic technetium-99m-complexes are widely used for myocardial perfusion imaging (MPI). However, inherent uncertainties in the supply chain of molybdenum-99, the parent isotope required for manufacturing 99Mo/99mTc generators, intensifies the need for discovery of novel MPI agents incorporating alternative radionuclides. Recently, germanium/gallium (Ge/Ga) generators capable of producing high quality 68Ga, an isotope with excellent emission characteristics for clinical PET imaging, have emerged. Herein, we report a novel 68Ga-complex identified through mechanism-based cell screening that holds promise as a generator-produced radiopharmaceutical for PET MPI.
High Resolution Electronic Spectroscopy Of The A 2 Σ − − X 2 Π 1/2 Transition Of Ptn, Kaitlin Womack, Sean Whittemore, James O'Brien, An Le, Timothy Steimle
High Resolution Electronic Spectroscopy Of The A 2 Σ − − X 2 Π 1/2 Transition Of Ptn, Kaitlin Womack, Sean Whittemore, James O'Brien, An Le, Timothy Steimle
Chemistry & Biochemistry Faculty Works
The (2,0) vibrational band of the A {sup 2}Σ{sup −} − X {sup 2}Π{sub 1/2} transition of platinum nitride, PtN, was recorded at Doppler-limited resolution using intracavity laser absorption spectroscopy (ILS) and at sub-Doppler resolution using molecular beam laser induced fluorescence (LIF) spectroscopy. Isotopologue structure for {sup 194}PtN, {sup 195}PtN, and {sup 196}PtN, magnetic hyperfine splitting due to {sup 195}Pt (I = ½), and nuclear quadrupole splitting due to {sup 14}N (I = 1) were observed in the spectrum. Molecular constants for the ground and excited states are derived. The hyperfine interactions are used to illuminate the nature of the …