Materials Literature
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Tissue-engineered heart valves have been proposed by physicians and scientists alike to be the ultimate solution for treating valvular heart disease. Rather than replacing a diseased or defective native valve with a mechanical or animal tissue-derived artificial valve, a tissue-engineered valve would be a living organ…
The hydrogen storage capacity in nanostructured carbon materials can be increased by atomic hydrogen spillover from a supported catalyst. A simple and effective technique was developed to build carbon bridges that serve to improve contact between a spillover source and a secondary receptor. In this work, a supported c…
A highly selective copper(II) ion fluorescent sensor has been designed based on the UV-visible absorption of a spiropyran derivative coupled with the use of a metal porphyrin operative on the fluorescence inner filter effect. Spiropyrans, which combine the characteristics of metal binding and signal transduction, have…
We report on a comprehensive combined experimental and theoretical study of Curie temperature trends in (Ga,Mn)As ferromagnetic semiconductors. Broad agreement between theoretical expectations and measured data allows us to conclude that ${T}_{c}$ in high-quality metallic samples increases linearly with the number of…
Acetoxylation of ethylene to vinyl acetate (VA) was used to investigate the mechanism of the promotional effect of gold (Au) in a palladium (Pd)-Au alloy catalyst. The enhanced rates of VA formation for low Pd coverages relative to high Pd coverages on Au single-crystal surfaces demonstrate that the critical reaction…
The structure of the interface generated by a spread layer of beta-casein on an aqueous colloidal poly(silicic) acid subphase is described. The results are compared with data for the protein alone spread at the air/water interface and the silicate solution. Films develop at the air-solution interface and a strong pH d…
A combined main-chain/side-chain liquid-crystalline polymer (PSHQ4−7CNCOOH), which is composed of poly[(phenylsulfonyl- p -phenylenene 1,4-tetramethylene bis(oxybenzoate)] (PSHQ4) as the main-chain backbone and 8-[(4-cyano-4‘-phenyl)oxy]octanoic acid (7CNCOOH) as the side-chain mesogenic groups, has been synthesized.…
Four generations of monodendrons with multiple dodecyl alkyl tails (AA-N, N representing number of alkyl tails from 1 to 8), an azobenzene spacer group, and a carboxylic acid polar head have been studied at the air-water and air-solid interface using AFM, GIXD, X-ray reflectivity, and UV-vis spectrometry. The one and…
We study a small system of spherically confined hard spheres using the Widom particle insertion method as an indicator for the ordering transition. By Monte Carlo simulations we determine the insertion probability as a function of the number of particles and the box size. We find an increase of the insertion probabili…
The effect of MCM-41 on the ESR spectrum of an aqueous spin probe solution was observed. The sharp ESR spectrum turns into a rather broad characteristic one leaving a sharper signal as the minor component, immediately after the addition of MCM-41 powder to the system. This observation indicates that MCM-41 traps the s…
The effect of applied strain on martensitic transformation in a superelastic Ti(46.4)Ni(47.6)Nb(6.0) alloy at room temperature was investigated by tensile tests, differential scanning calorimetry measurements, and X-ray diffraction. Reverse transformation starting (A(s)) and finishing (A(f)) temperatures increased wit…
BACKGROUND: The alkaline protease from Pseudomonas aeruginosa (AprA) is a member of the metzincin superfamily of metalloendoproteases. A key feature of these proteases is a conserved methionine-containing 1,4-tight beta turn at the base of the active site zinc binding region. RESULTS: To explore the invariant methioni…
A network of screw dislocations was artificially created in SrTiO3, and characterized by transmission electron microscopy (TEM). Slight expansion of the dislocation core was observed by TEM. The composition of the dislocation core was quantified by electron energy loss spectroscopy, which reveals a 13±5% Ti∕O ratio in…
A single step sol-gel process was used to precipitate silica microspheres containing ibuprofen or naproxen for controlled drug delivery applications. The drug release behavior from these systems was analyzed in vitro. Pure ibuprofen and naproxen exhibited linear release with time, while sol-gel silica entrapped drugs…
Abstract The first example of a porphyrin‐quinonoid donor–acceptor triad featuring (tetraphenylporphinato)zinc( II ) moieties covalently attached to an oxoporphyrinogen through its macrocyclic nitrogen atoms is reported. This arrangement of chromophores results in an interesting interplay between the electron‐donating…
Längst überfällig: Die Kristallstruktur der metastabilen Form von Benzamid (siehe Bild), deren Existenz seit über 170 Jahren bekannt war, ist endlich aufgeklärt worden – durch eine Kombination von In-situ-Kristallisation, Hochgeschwindigkeits-Synchrotronröntgenpulverbeugung und globalen Optimierungsmethoden zur Strukt…
One of the essential parts in the molecular mechanism of biological properties is the structural changes of proteins induced by stimuli. An amphiphilic copolymer, poly(L-leucine) grafted polyallylamine as a simple model of proteins, has been prepared by NCA polymerization with free amino groups of polyallylamine as an…
Abstract An overview is given on the electronic and optical properties of Si and Ge nanocrystals. We model free‐standing Si and Ge nanocrystals passivated with H, with up to 363 group‐IV atoms and 276 H and oxidized nanocrystals with additional silicon oxide shells, e.g. Si 41 (O 60 Si 42 )(O 108 Si 64 )H 148 . The re…
Deformation twinning occurs in various materials including metals, intermetallics, ceramics, superconductors, and even geological systems. The rate of twin growth depends on the material system, but there are no crystallographic models to understand the mechanisms of slow twin growth. The physics of twin growth is pre…
The a.c. conductivity σa.c(ω), the dielectric constant ϵ′ and dielectric loss ϵ″ of polycarbonate sheet have been studied in the frequency range 1.5 × 102–5 × 106 Hz and temperature range 294–473 K. A.c. conductivity σa.c(ω) results show that it depends strongly on the frequency and slightly on the temperature, with a…