A5086787067- Advanced NMR Techniques and Applications
- Concrete Corrosion and Durability
- Solid-state spectroscopy and crystallography
- Corrosion Behavior and Inhibition
- NMR spectroscopy and applications
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Glass properties and applications
- Phase-change materials and chalcogenides
- Inorganic Fluorides and Related Compounds
- Advanced Battery Materials and Technologies
- Fuel Cells and Related Materials
- Chemical Synthesis and Characterization
- Advanced MRI Techniques and Applications
- Silk-based biomaterials and applications
- Hydrogen embrittlement and corrosion behaviors in metals
- Biochemical and Structural Characterization
- Photosynthetic Processes and Mechanisms
- Crystallography and molecular interactions
- Porphyrin and Phthalocyanine Chemistry
- Polyoxometalates: Synthesis and Applications
- Protein Structure and Dynamics
- Material Dynamics and Properties
- Vanadium and Halogenation Chemistry
- Luminescence and Fluorescent Materials
Arizona State University
2015-2025
Resonance Research (United States)
2011-2025
Tempe Union High School District
2016
Monash University
1998-2008
Sandia National Laboratories
2002-2005
Office of Scientific and Technical Information
2005
National Technical Information Service
2005
Pacific Northwest National Laboratory
2005
Sandia National Laboratories California
2002-2005
Indiana University Bloomington
2002-2003
The heteropolyanions of W, Mo, and V, which have found numerous applications, are formed simply by acidification solutions their oxoanions. Under similar conditions, these oxoanion precursors not available for Nb, Nb-oxo chemistry is dominated formation the Lindquist ion [Nb 6 O 19 ] 8– only. However, heteropolyniobate favored in hydrothermal reactions aqueous, alkaline precursor mixtures. Here we give two examples heteropolyniobates this general reaction type: K 12 [Ti 2 ][SiNb 40 ]·16H...
The goal of this work was to nondestructively measure glomerular (and thereby nephron) number in the whole kidney. Variations and size glomeruli have been linked many renal systemic diseases. Here, we develop a robust magnetic resonance imaging (MRI) technique based on injection cationic ferritin (CF) produce an accurate measurement individual glomeruli. High-field (19 Tesla) gradient-echo MR images perfused rat kidneys after vivo intravenous CF showed specific labeling with throughout We...
Nature employs a TyrZ-His pair as redox relay that couples proton transfer to the process between P680 and water oxidizing catalyst in photosystem II. Artificial relays composed of different benzimidazole-phenol dyads (benzimidazole models His phenol Tyr) with substituents designed simulate hydrogen bond network surrounding have been prepared. When benzimidazole are strong acceptors such primary or tertiary amines, theory predicts concerted two associated electrochemical oxidation will take...
Many natural silks produced by spiders and insects are unique materials in their exceptional toughness tensile strength, while being lightweight biodegradable-properties that currently unparalleled synthetic materials. Myriad approaches have been attempted to prepare artificial from recombinant spider silk spidroins but each failed achieve the advantageous properties of material. This is because an incomplete understanding vivo spidroin-to-fiber spinning process and, particularly, a lack...
Solid-state 1H, 17O MAS NMR, 1H−93Nb TRAPDOR and 1H double quantum 2D NMR experiments were used to characterize the oxygen, water, hydroxyl environments in monoprotonated hexaniobate material, Na7[HNb6O19]·15H2O. These solid-state demonstrate that proton is located on bridging oxygen of [Nb6O19]8- cluster. The results also show NbOH protons are spatially isolated from similar protons, but undergo exchange with water species crystal lattice. On basis measurements, it was determined lattice...
Abstract Sensing and responding to temperature is crucial in biology. The TRPV1 ion channel a well-studied heat-sensing receptor that also activated by vanilloid compounds, including capsaicin. Despite significant interest, the molecular underpinnings of thermosensing have remained elusive. S1-S4 membrane domain couples chemical ligand binding pore during gating. Here we show significantly contributes heat-activated Evaluation isolated human solution NMR, far-UV CD, intrinsic fluorescence...
Abstract The focal adhesion kinase (FAK) scaffold provides FAK-targeted cancer therapeutics with greater efficacy and specificity than traditional inhibitors. FAK function largely involves the interaction between FAK’s targeting (FAT) domain paxillin, ultimately regulating many hallmarks of cancer. We report design paxillin LD-motif mimetics that successfully inhibit FAT-paxillin interaction. Chemical biochemical screening identifies stapled peptide 1907, a high affinity binder FAT...
A method for radical coupling of porphyrins using copper(II) salts as one-electron oxidants was developed. Zn(II)-porphyrin bearing an aminophenyl group yielded porphyrin oligomers, and two tri-arylporphyrins were oxidized to form doubly triply linked dimers. Bromination dimers gave macrocycles with twisted skeletons.
Solid-state NMR and molecular dynamics (MD) simulations are presented to help elucidate the secondary structure of poly(Gly-Gly-X), which is one most common structural repetitive motifs found in orb-weaving dragline spider silk proteins. The combination computational experiments provides insight into poly(Gly-Gly-X) segments further support that these regions disordered primarily non-β-sheet. Furthermore, MD illustrate possibility for several elements silks, including β-turns, 3
Upon solution in water, both [hydroxy(mesyloxy)iodo]benzene and [hydroxy(tosyloxy)iodo]benzene undergo complete ionization to give the hydroxy(phenyl)iodonium ion (PhI+OH) corresponding sulfonate (RSO2O-) as fully solvated species, i.e., "free" ions. The phenyliodonium species do not form pairs with organosulfonate is presumed be ligated at least one water molecule an apical site of iodine(III) atom originally occupied by ion. In view relative basicities HO- H2O, hydroxy ligand...
A recently reported synthetic method has been employed to prepare several arrays of free base and zinc porphyrins. In the arrays, porphyrins are arranged around a central benzene ring. The lack aryl rings in linkages ring, coupled with presence only one meso-aryl substituent on each porphyrin, allows strong electronic interactions between porphyrin macrocycles. containing two or six porphyrins, variety evidence indicates that exist as twist-stacked dimers reminiscent special pairs...
Cacti thrive in xeric environments through specialized water storage and collection tactics such as a shallow, widespread root system that maximizes rainwater absorption spines adapted for fog droplet collection. However, many cacti, the epidermis, not spines, dominates exterior surface area. Yet, little attention has been dedicated to studying interactions of cactus epidermis with drops. Surprisingly, plants genus Opuntia, also known prickly pear water-repelling characteristics. In this...
Solid-state 1H magic angle spinning (MAS) NMR was used to investigate sulfonated Diels−Alder poly(phenlylene) polymer membranes. Under high speed MAS conditions, the proton environments of sulfonic acid and phenylene backbone are resolved. A double-quantum (DQ) filter using rotor-synchronized back-to-back (BABA) multiple-pulse sequence allowed selective suppression environment in spectra. This DQ conjunction with a spin diffusion experiment then measure domain size component within membrane....
Two molecules in which the intensity of shorter-wavelength fluorescence from a strong fluorophore is modulated by longer-wavelength irradiation an attached merocyanine-spirooxazine reverse photochromic moiety have been synthesized and studied. This unusual behavior result quenching thermally stable, open, zwitterionic form spirooxazine, whereas photogenerated closed, spirocyclic has no effect on excited state. The population ratio closed open forms spirooxazine controlled light. Both square...
Natural glues offer great potential as bio-inspired solutions to problems associated with the performance of synthetic adhesives. Spider viscous are elastic pressure sensitive adhesives (PSAs) that physically adhere surfaces on contact across a range environmental conditions. Extracting useful components from these secretions remains challenge can be met by comparative analyses functional analogues. Here we used 1 H NMR spectroscopy and mass spectrometry ascertain organic salt compositions...
Ab initio calculations of the 17O electrical field gradient (EFG) tensor quadrupolar coupling constant (CQ) and asymmetry parameter (ηQ), along with NMR isotropic chemical shift (δiso) for three crystalline polymorphs P2O5 are presented. These computational results compared experimental values h-P2O5 (hexagonal-form) obtained using a combination solid-state magic angle spinning (MAS) at different magnetic strengths (9.4, 14.1, 19.6 T), two-dimensional (2D) multiple-quantum (MQ)MAS NMR, 2D...