Materials Literature
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In Bacillus subtilis, the NADPH-dependent glyceraldehyde-3-phosphate dehydrogenase (GapB) and the phosphoenolpyruvate carboxykinase (PckA) enzymes are necessary for efficient gluconeogenesis from Krebs cycle intermediates. gapB and pckA transcription is repressed in the presence of glucose but not via CcpA, the major…
A molecular double-throw switch that employs a photochromic moiety to direct photoinduced electron transfer from an excited state donor down either of two pathways has been prepared. The molecular triad consists of a free base porphyrin (P) linked to both a C(60) electron acceptor and a dihydroindolizine (DHI) photoch…
Substantial alignment of isolated individual single-wall carbon nanotubes (SWNTs) has been achieved by mechanically stretching gelatin films filled with homogeneously dispersed SWNTs. Highly polarized absorption and photoluminescence are observed that are attributed to interband optical transitions in SWNTs. Sharp and…
Covalent ties: The polyoxometalate (nBu4N)3[(MeO)TiW5O18] is easily anchored to alkanol-functionalized surfaces of porous and single-crystal silicon (see picture, polyhedra: polyoxometalate, dark blue: Si surface). Scanning tunneling microscopy reveals the growth of 35–50 nm diameter islands on functionalized Si(111),…
The energy level alignment (see Figure) at interfaces between pentacene and thin films of conducting polymers (made from ethylenedioxythiophene and sulfonate moieties) is found to be independent of initial polymer work function or morphology. Interfacial chemical reactions control the energy level alignment, rather th…
We show that hydrogen-bonded multilayer thin film coatings assembled on colloidal particles can be used as templates for the in situ synthesis of nanoparticles. The concentration and size of nanoparticles grown within the coatings can be tuned by the number of loading cycles. The hydrogen-bonded multilayer thin films…
Nanostructural control of gallium oxide formation is achieved at low temperatures by the enzyme-catalyzed hydrolysis and polycondensation of gallium oxide precursors. Filaments of silicatein, a hydrolase originally discovered in a marine sponge, catalyze the hydrolysis of gallium(III) nitrate, producing oriented nanoc…
Photochromic conductivity modulation of conjugated polymers containing a diarylethene unit with high photochromic conversion ratios is described. The electrical conductivity can be switched quasi-reversibly from the bleached low-conductivity state (Figure, left) and the blue high-conductivity state (right) by alternat…
We have fabricated n-type carbon nanotube field effect transistors by choosing the contact metal. Single-walled carbon nanotubes were grown directly on a SiO2∕Si substrate by chemical vapor deposition using patterned metal catalysts. Following the nanotube growth, Ca contacts with a small work function were formed by…
Single- or multicolor-encoded microspheres are created by confining water-soluble CdTe nanocrystals with different sizes within hydrogel microspheres of N-isopropylacrylamide and 4-vinylpyridine copolymer based on the pH-responsive swelling behavior of the gel (see Figure). The emission intensity level and color of th…
In the present article, we report adsorption energies, structures, and vibrational frequencies of CO on Fe(100) for several adsorption states and at three surface coverages. We have performed a full analysis of the vibrational frequencies of CO, thus determining what structures are stable adsorption states and charact…
Abstract The crystallization behavior of poly(3‐hydroxybutyrate) (PHB) and poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyvalerate) (PHBV) induced by two kinds of nucleating agents, boron nitride (BN) and talc, was investigated by differential scanning calorimetry, polarized optical microscopy and X‐ray diffraction. Both BN and…
Se and Te nanowires (NWs) are spontaneously formed in solution through chemical decomposition of stabilizer-depleted nanoparticles (NPs) in the presence of a strong complexing agent. Highly crystalline Se and Te NWs with monodisperse lateral sizes, in the range 10–100 nm, are produced (see Figure and cover). This work…
We experimentally and theoretically studied a left-handed structure based on a photonic crystal (PC) with a negative refractive index. The structure consists of triangular array of rectangular dielectric bars with dielectric constant 9.61. Experimental and theoretical results demonstrate the negative refraction and th…
Guest–host composites with improved dispersion of guest species can be fabricated using a new method that exploits the confined space between the silica walls and templated aggregates in as-prepared mesoporous materials. This produces mesoporous functional composites with high oxide dispersions with potential applicat…
We report on measurements of the crystal structure and hole density in a series of as-grown and annealed GaMnAs samples. The measured hole densities are used to obtain the fraction of incorporated Mn atoms occupying interstitial and substitutional sites. This allows us to make a direct comparison of the measured latti…
We demonstrate tunable room-temperature amplified spontaneous emission and lasing from blue-emitting core-shell CdS∕ZnS nanocrystals (NCs) stabilized in a sol-gel derived silica matrix. Variable stripe length measurements show that these NC-silica composites have a modal gain of ∼100cm−1 at room temperature. Coating m…
Polymerization of polyaniline in the presence of carbon nanotubes results in a soluble carbon nanotube/polyaniline composite (Figure, left) displaying enhanced thermal and electrical properties. Polyaniline in the proximity of nanotubes grows in a more planar conformation due to strong π–π interactions simultaneously…
Single-crystalline gold nano- and microplates with triangular or hexagonal shapes are synthesized by reduction of HAuCl(4) in lyotropic liquid crystal (LLC) mainly made of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers and water after adding a small amount of capping agents, cetyltrim…
Different ways of dealing with one-dimensional (1D) spectra, measured e.g. in the Compton scattering or angular correlation of positron annihilation radiation (ACAR) experiments are presented. On the example of divalent hexagonal close packed metals it is shown what kind of information on the electronic structure one…