Materials Literature
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A novel tripeptide motif called a nest has recently been described in proteins with the function of binding anionic, or partially anionic, atoms such as carbonyl O atoms. In the present work, a search for nests in small polypeptides stored in the Cambridge Structural Database is reported. 37 unique examples were found…
Type I polyhydroxyalkanoate (PHA) synthases, as represented by Ralstonia eutropha enzyme (PhaC(Re)), have narrow substrate specificity toward (R)-3-hydroxyacyl-coenzyme A with acyl chain length of C3-C5 to yield PHA polyesters. In this study, saturation point mutagenesis of a highly conserved alanine at position 510 (…
Reaction of 5,5-dimethyldipyrromethane (1) with electron-deficient aryl aldehydes in the presence of BF(3)-Et(2)O and NH(4)Cl in propionitrile constitutes efficient, easy access to unprecedented, functional porphomonomethenes together with the expected porphodimethenes (calix[4]phyrins). Alternatively, when the reacti…
Micellization in sodium dodecyl sulfate (SDS)-N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate and SDS-polyoxyethylenesorbitan monolaurate binary surfactant solutions was studied by means of conductivity and surface tension measurements. These studies showed that two types of micellar aggregates are present in the…
Verknüpfte Ringe: Ein direkt β-β-verknüpftes Dimer (siehe Abbildung) aus N-invertierten Porphyrinen wurde durch eine einfache säurekatalysierte Kondensation der monomeren Makrocyclen erhalten. Die elektronische Wechselwirkung zwischen den Porphyrinuntereinheiten wurde sowohl für die freie Base als auch für den Bis(nic…
The thermal stability of anatase TiO 2 nanoparticles, produced by flame synthesis, is investigated in the current study. Phase-pure anatase particles of ∼4 nm in size can be reproducibly synthesized by using a tubular burner and rotating sampler. Transmission electron microscopy (TEM), glancing incidence X-ray diffrac…
Abstract We report the coating of maghemite (γ‐Fe 2 O 3 ) nanoparticles with poly(ε‐caprolactone) (PCL) through a covalent grafting to technique. ω‐Hydroxy‐PCL was first synthesized by the ring‐opening polymerization of ε‐caprolactone with aluminum isopropoxide and benzyl alcohol as a catalytic system. The hydroxy end…
Rare earth (RE) and group III oxide additions are frequently used to optimize densification during the processing of ceramics. Silicon nitride ceramics frequently serve as model cases, and in these systems the effects of rare earths are important. Additions often determine the morphology of $\ensuremath{\beta}\text{\e…
The structure and reactivity of high-valent FeVO and MnVIO oxidation catalysts containing a polyoxometalate [PW11O39]7− lacunary ligand (2) have been investigated by a computational study. Calculations have demonstrated there is an intriguing analogy between these species and the active species (1) of the enzyme cytoc…
Genome sequence data of the cold-adapted archaeon, Methanococcoides burtonii, was linked to liquid chromatography-mass spectrometry analysis of the expressed-proteome to define the key biological processes functioning at 4 degrees C. 528 proteins ranging in pI from 3.5 to 13.2, and 3.5-230 kDa, were identified. 133 id…
Dendrimers, specifically suited to construct site-isolated groups due to their well-defined hyperbranched structure, have been used as a ligand design element for the construction of nickel catalysts for ethylene oligomerization. The dendritic P,O ligand indeed suppresses the formation of inactive bis(P,O)Ni complexes…
Impurities have a clear negative influence on the nucleation and growth rate kinetics of the semisynthetic antibiotic ampicillin (AMPI) crystallization. The tested impurities phenylglycine and 6-aminopenicillanic acid are the building blocks of AMPI and will therefore be present in any AMPI manufacturing process, as w…
meso-Functionalized dipyrromethanes 6-10 were synthesized by acid-catalyzed addition of pyrrole to <TEX>${\alpha}$</TEX>-position of 2-alkenyl pyrroles. The regiochemistry of the reaction can be explained by either the formation of more stable carbocation intermediate or <TEX>${\beta}$</TEX>-addition of <TEX>${\alpha}…
Abstract The effect of high hydrostatic pressure on Y 3 Al 5 O 12 (YAG) single crystals has been studied up to 15 GPa by Raman spectroscopy at room temperature. The pressure dependence of 23 Raman‐active modes, out of 25 predicted by group theory, has been followed. The determined mode Grüneisen parameters ( γ i ) ext…
Abstract Summary: The thermal and structural analysis of silk fibroin (SF) and silk sericin (SS) blend films reveals that the crystallization of SF is retarded in the presence of SS. Although a phase separation was observed, there might be a strong interaction at the boundary of the SF and SS through intermolecular hy…
Tripyrranes were condensed with 1,3,5-cycloheptriene-1,6-dicarbaldehyde in TFA-CH(2)Cl(2) to give, following oxidation with 0.1% aqueous ferric chloride solutions, a series of tropiporphyrins 9. These cycloheptatrienyl analogues of the porphyrins show strong diatropic ring currents by proton NMR spectroscopy where the…
We report Raman scattering and x-ray diffraction studies of polycrystalline $\mathrm{Ca}{\mathrm{Cu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$ (CCTO) under high pressures. The pressure dependence of several Raman modes was investigated. No anomalies have been observed on the phonon spectra thereby indicating that the ${…
Neutron scattering has been used to study the nature of the ferromagnetic transition in single crystals of ${\mathrm{La}}_{0.7}{\mathrm{Ca}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ and ${\mathrm{La}}_{0.8}{\mathrm{Ca}}_{0.2}\mathrm{Mn}{\mathrm{O}}_{3}$, and polycrystalline samples of ${\mathrm{La}}_{0.67}{\mathrm{Ca}}_{0.33…
The synthesis and magnetic properties of three isostructural hexadecametallic manganese clusters [Mn(16)O(16)(OMe)(6)(O(2)CCH(2)Ph)(16)(MeOH)(6)] (1), [Mn(16)O(16)(OMe)(6)(O(2)CCH(2)Cl)(16)(MeOH)(6)] (2), and [Mn(16)O(16)(OMe)(6)(O(2)CCH(2)Br)(16)(MeOH)(6)] (3) are reported. The complexes were prepared by a reductive…
There's nothing confusing about the dimer (see picture) that forms from N-confused porphyrin! The dimer was obtained as a directly β–β-linked structure through a simple acid-catalyzed condensation reaction of the monomeric macrocycles, and the electronic interaction between the porphyrin subunits was studied for both…