Materials Literature
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Unter Kontrolle! Ag2S-Nanokristalle mit vorhersagbarer Größe und Form sind aus Ag(SCOPh) in Gegenwart eines Amins zugänglich. Sorgfältiges Einstellen von Parametern wie der Reaktionstemperatur und dem Verhältnis Amin:Ausgangsverbindung lieferte Ag2S-Nanokristalle unterschiedlicher Größe und Morphologie (rot: Nanowürfe…
Abstract We present an XPS method to determine the termination of the ZnO(0001) surface. By measuring O 1s and Zn 2p 3/2 core‐level x‐ray photoelectron spectra at photoemission angles of 0° and 70° and comparing the intensity ratio ( I O1s / I Zn2p3 ) θ=0 /( I O1s / I Zn2p3 ) θ=70 , the Zn and O termination can be dis…
Substructure-solution and phasing procedures using a combination of anomalous scattering and radiation-damage-induced isomorphous differences have been investigated. The tyrosine residues in thaumatin were iodinated with N-iodosuccinimide in the crystalline form as well as prior to crystallization. Several data sets w…
Abstract An effective interionic interaction potential (EIOP) is developed to investigate the pressure induced phase transitions from NaCl‐type ( B 1) to CsCl‐type ( B 2) structure in lanthanum monochalcogenides LaX [X = S, Se, Te] compounds. The long range Coulomb, van der Waals (vdW) interaction and the short‐range…
Escherichia coli argininosuccinate lyase has been crystallized from a highly concentrated sample of purified recombinant alpha-methylacyl-CoA racemase, in which it occurred as a minor impurity. The structure has been solved using molecular replacement at 2.44 A resolution. The enzyme is tetrameric, but in this crystal…
Structural studies of a ternary complex composed of the Yersina pestis virulence factors YopN, SycN and YscB were initially hampered by poor solubility of the individual proteins. Co-expression of all three proteins in Escherichia coli yielded a well behaved complex, but this sample proved to be recalcitrant to crysta…
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…