Materials Literature
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Polyhydroxybutyrate (PHB) synthases catalyze the polymerization of (R)-3-hydroxybutyryl-CoA (HB-CoA) into high molecular weight PHB, biodegradable polymers. The class III PHB synthase from Allochromatium vinosum is composed of a 1:1 mixture of two approximately 40 kDa proteins: PhaC and PhaE. Previous studies using si…
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The internal nanomorphologies of two types of vinyl polymer-silica colloidal nanocomposites were assessed using electron spectroscopy imaging (ESI). This technique enables the spatial location and concentration of the ultrafine silica sol within the nanocomposite particles to be determined. The ESI data confirmed that…
Cyanamide (NH(2)CN), an interstellar molecule, is a relevant molecule in prebiotic chemistry, because it can be converted into urea in liquid water. Carbodiimide (HNCNH), the most stable cyanamide isomer, is able to assemble amino acids into peptides. In this work, using FTIR spectroscopy, we show that carbodiimide ca…
Submicrometer-sized inorganic−organic composite particles with disklike, cell-like, and hemispheroidal shapes have been fabricated by in-situ mineralization of CaCO 3 within hydrogel spheres of poly( N -isopropylacrylamide- co -(4-vinylpyridine)) (PNIPVP). The shape and functionality of the composite particles obtaine…
The optical gas recognition capability of a covalently self-assembled monolayer of 5,10,15-tri-{ p -dodecanoxyphenyl}-20-( p -hydroxyphenyl) porphyrin molecules on silica substrates was studied. The following analytes have been investigated: NO 2, CO, CH 4, H 2, NH 3, HCl, CHCl 3, C 2 H 5 OH, CH 3 OH, pyridine, tetrah…
We present in-situ observations of the epitaxial nucleation of the metastable polymorph of a steroid on specific faces of the stable form in different solutions using optical microscopy. The polar morphology of the crystals allows for the determination of the specific face where the epitaxial nucleation takes place. T…
Crystallization of organic compounds in nanometer-scale channels of controlled pore glass (CPG) and porous polystyrene (p-PS), the latter prepared by etching of the polylactide (PLA) component of shear-aligned PS-PLA diblock copolymers, produces crystals with dimensions that reflect the size constraints imposed by the…
High-density large-area nanowire arrays of thermoelectric material Sb 2 Te 3 have been successfully prepared using electrochemical deposition into the channels of the porous anodic alumina membrane. The morphologies, structure, and composition of the as-prepared Sb 2 Te 3 nanowires have been characterized using field-…
We review analytical and numerical results for surface-directed spinodal decomposition (SDSD), namely, the interplay of wetting kinetics and phase separation in a binary (AB) mixture in contact with a surface S which prefers one of the components (say, A). Depending on the relative strengths of the A–B, A–S and B–S in…
An extensive optical and photoelectrochemical study of blended systems composed of organic-capped TiO(2) nanocrystals with either a spherical or rodlike morphology and a conjugated polymer, MEH-PPV, is presented. The absorption and emission properties of the heterojunctions have been characterized both in solution and…
We report the crystal structure of alanine racemase from Mycobacterium tuberculosis (Alr(Mtb)) at 1.9 A resolution. In our structure, Alr(Mtb) is found to be a dimer formed by two crystallographically different monomers, each comprising 384 residues. The domain makeup of each monomer is similar to that of Bacillus and…
Grafting of poly(ethylene glycol) (PEG) is a common strategy for reducing nonspecific interactions of surfaces with proteins. We have used grafting at "cloud point" solution conditions that ensures maximum grafting density of linear methoxy terminated PEG-aldehyde (mPEG-ald, M(w) = 5000 and 30000). In an alternative a…
The electronic structure and the conductance of a carbon nanotube based metal/semiconductor/metal intramolecular junction is investigated numerically. The nature of electronic states at the interfaces and in the semiconductor section is analysed. The quantum conductance of the system is calculated in the coherent regi…
High molecular weight polymer solutions have a powerful tendency to deposit adsorbed layers when exposed to even mildly attractive surfaces. The equilibrium properties of these dense interfacial layers have been extensively studied theoretically. A large body of experimental evidence, however, indicates that non-equil…
Silver paint has been tested as a soldering agent for DyBaCuO single-domain welding. Junctions have been manufactured on Dy-Ba-Cu-O single-domains cut either along planes parallel to the c-axis or along the ab-planes. Microstructural and superconducting characterisations of the samples have been performed. For both ty…
The paper describes a study of the magnetic, transport and magnetoresistive properties of La_{1-x}Ca_{x}MnO_{3} (x\approx 0.33) crystals prepared by the floating-zone method. We found that these properties testify to rather good crystal perfection of the sample studied. In particular, a huge magnetoresistance ([R(0)-R…
Nanostructured Fe dots were prepared on antiferromagnetic FeF2 thin films and investigated by magneto-optical Kerr effect (MOKE). We studied the influence of dot sizes on the magnetic hysteresis and compared the result with both continuous thin film bilayers and nanostructured Fe/FeF2 pillars. Hysteresis loops were me…
We propose a spin-mechanical device to control and detect spin currents by mechanical torque. Our hybrid nano-electro-mechanical device, which contains a nanowire with a ferromagnetic-nonmagnetic interface, is designed to measure or induce spin polarized currents. Since spin carries angular momentum, a spin flip or sp…
We propose a structural path for the icosahedra <-> fcc transition in clusters and demonstrate the transition in Pb_13 by ab initio molecular-dynamics simulation. The proposed path can be described by using only two variables. The energy surface on this two-dimensional space for Pb_13 was calculated and a barrierless…