Materials Literature
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BtuB is a bacterial outer-membrane protein that transports vitamin B(12). Spectroscopic studies using site-directed spin labeling (SDSL) indicate that the N-terminus of BtuB undergoes a dramatic structural change from a docked (folded) to an undocked (unfolded) configuration upon substrate binding. However, this drama…
The selective and permanent titration of protons with organic bases (2,6‐di‐ tert ‐butylpyridine or pyridine) provides an accurate measure of the dispersion of Keggin structures during catalytic oxidation of methanol. Titration allows the systematic control of the redox and acid properties of H 3+ n PV n Mo 12− n O 40…
A novel method for transferring silver nanoparticles from aqueous solution into organic solvents such as toluene or hexane was developed. Phase-transfer reagent, tri- n -octylphosphine oxide, TOPO, provides a capping shell around Ag particles that enables concentrating nanoparticle dispersion in toluene, which is a pr…
The crystal structures of bovine pancreatic ribonuclease A (RNase A) in complex with 3',5'-ADP, 2',5'-ADP, 5'-ADP, U-2'-p and U-3'-p have been determined at high resolution. The structures reveal that each inhibitor binds differently in the RNase A active site by anchoring a phosphate group in subsite P1. The most pot…
A unique epitaxial growth method, reactive solid-phase epitaxy, was used to fabricate heteroepitaxial thin films of LaCuOS, a transparent p-type semiconductor with layered structure. The epitaxial growth mechanism is examined through microscopic observations. A thin metallic Cu layer deposited between the amorphous La…
Hydrocalumite, Ca 2 Al(OH) 6 (anion)· n H 2 O, belongs to the layered double-hydroxide family, with the particularity for both intralayered cations and interlayered anions and water molecules to be well-ordered. The monomer vinyl benzene sulfonate (VBS) and the syndiotactic polymer poly(styrene sulfonate) (PSS) were r…
The crystal structures of lactose repressor protein (LacI) provide static endpoint views of the allosteric transition between DNA- and IPTG-bound states. To obtain an atom-by-atom description of the pathway between these two conformations, motions were simulated with targeted molecular dynamics (TMD). Strikingly, this…
Aqueous phase catalytic oxidation of ammonia has been studied over Ru/TiO2 catalyst in a batch reactor by changing the solution pH, concentration of catalyst in the solution, temperature, and reaction time. The oxidation reaction of ammonia over Ru/TiO2 catalyst has been found to take place exclusively for the aqueous…
A new approach for the formation of bimetallic coordination complexes of bismuth containing a 1:1 ratio of the two metal species has been developed. The strategy exploits the Lewis acidic nature of bismuth and has been used to synthesize the new complexes BiV(O)(Hsal)(sal)(salen*)·CH 2 Cl 2 ( 1 ), BiCu(Hsal) 3 (salen)…
The incorporation of tetravalent cations (Zr 4+ and Sn 4+ ) inside sheets of layered double hydroxide (LDH) was reported by Velu et al. As no local structural information was provided so far, the question here is whether the LDH structure may accommodate such a presence. From three different systems presenting the cat…
Hyperbranched poly( ε -caprolactone)s (HPCLs) were synthesized by moisture-sensitive catalyst-free polycondensation of AB 2 macromonomers, 2,2-bis[ω-hydroxy oligo( ε -caprolactone)methyl]propionic acids. The HPCLs were designed to incorporate different lengths of linear oligomeric segments consisting of 5, 10, and 20…
Abstract The conductivity of styrene‐butadiene‐styrene block copolymers containing different amounts of extraconductive carbon black (CB) was investigated as a function of the mold temperature. The composites exhibited reduced percolation thresholds (between 1.0 and 2.0 vol % CB). The dynamic mechanical analysis chara…
Abstract The phase structure of crystalline isotactic polystyrene (iPS) has been investigated with temperature‐modulated differential scanning calorimetry (TMDSC), wide‐angle X‐ray scattering (WAXS), and Fourier transform infrared (FTIR) spectroscopy. Quenched amorphous samples have been cold‐crystallized at 140 or 17…
Thin CdSe layers (“quantum shells”) were epitaxially grown onto CdS nanocrystal templates. Their optical properties are dominated by the shell thickness despite the different bandgap and size of the templates. The emission of the CdSe quantum shells, which can be tuned by varying the shell thickness, ranges from 520 t…
The structure of the phases obtained upon dehydration and decomposition of Friedel's salt [Ca 2 Al(OH) 6 ]Cl·2H 2 O, also known as hydrocalumite, was investigated by several experimental techniques, in particular, high-temperature in situ XRD measurements, which allowed the detection of a metastable intermediate phase…
Si deposition on H terminated Si(100)-2x1 and 3x1 surfaces at temperatures 300-530 K is studied by scanning tunneling microscopy. Hydrogen apparently hinders Si adatom diffusion and enhances surface roughening. The post-growth annealing effect is analyzed. Hydrogen is shown to remain on the growth front up to at least…
We discuss the anomalous Hall effect in a two-dimensional electron gas subject to a spatially varying magnetization. This topological Hall effect (THE) does not require any spin-orbit coupling, and arises solely from Berry phase acquired by an electron moving in a smoothly varying magnetization. We propose an experime…
We develop a new concept for active plasmonics exploiting nanoscale structural transformations which is supported by rigorous numerical analysis. We show that surface plasmon-polariton signals in a metal-on-dielectric waveguide containing a gallium section a few microns long can be effectively controlled by switching…
The appearance of "magic" heights of Pb islands grown on Cu(111) is studied by self-consistent electronic structure calculations. The Cu(111) substrate is modeled with a one-dimensional pseudopotential reproducing the essential features, i.e. the band gap and the work function, of the Cu band structure in the [111] di…
We study the interactions of the vortex lattice with a periodic square array of holes in a superconducting Nb film using magnetic and resistive measurements. Three different temperature regions have been observed. They are governed by interplay between vortex-vortex interactions and pinning by holes. At low temperatur…