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Marcel Meury Matthias Knop Florian P. Seebeck 《Angewandte Chemie (International ed. in English)》2017,56(28):8115-8119
The formylglycine-generating enzyme (FGE) is a unique copper protein that catalyzes oxygen-dependent C−H activation. We describe 1.66 Å- and 1.28 Å-resolution crystal structures of FGE from Thermomonospora curvata in complex with either AgI or CdII providing definitive evidence for a high-affinity metal-binding site in this enzyme. The structures reveal a bis-cysteine linear coordination of the monovalent metal, and tetrahedral coordination of the bivalent metal. Similar coordination changes may occur in the active enzyme as a result of CuI/II redox cycling. Complexation of copper atoms by two cysteine residues is common among copper-trafficking proteins, but is unprecedented for redox-active copper enzymes or synthetic copper catalysts. 相似文献
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Consistent time and frequency domain formulations for a fully anisotropic, linear visco-elastic material model are presented. The finite element implementation leads to a complex valued stiffness matrix in the frequency domain. A homogenisation procedure based on unit-cell analyses in the frequency domain is presented to derive input parameters for the material model. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Christian Schenk Florian Henke Andreas Schnepf 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1370-1374
Abstract Metalloid cluster compounds of group 14 of the general formulae EnRm with n > m (E = Si, Ge, Sn, Pb; R = ligand), where naked as well as ligand bound tetrel atoms are present, represent a novel class of cluster compounds in group 14 chemistry and can be seen as intermediates on the way to the elemental state. Therefore, interesting properties are expected for these compounds, which might complement results from nanotechnology. In this article, first results for germanium are discussed, together with novel build-up reactions on the way to novel materials based on metalloid cluster compounds. GRAPHICAL ABSTRACT 相似文献
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Maria Carmen Florian Eric Condamine loïc Toupet Yvan Ramondenc Gérard Plé 《Supramolecular chemistry》2013,25(6):383-392
The synthesis and the structure of new macrocycles containing semiflexible dispiro-1,3-dioxane units is reported. The structural analysis of the compounds is performed by high field NMR spectra, mass spectrometry investigations (MALDI, ESI-MS) and the solid state molecular structure obtained for two compounds by single crystal X-ray diffractometry. The dynamics of the macrocycles promoted by the flipping of the middle cyclohexane ring of the dispirane units is investigated using low temperature NMR experiments. New macrocycles containing dispiro-1,3-dioxane units were investigated by NMR, X-ray diffractometry and mass spectrometry 相似文献
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Dr. Claudia Kolbeck Dr. Alexey Deyko Dr. Takashi Matsuda Florian T. U. Kohler Prof. Dr. Peter Wasserscheid Dr. Florian Maier Prof. Dr. Hans-Peter Steinrück 《Chemphyschem》2013,14(16):3726-3730
We present the first systematic study of the influence of temperature on the degree of surface enrichment of 1-alkyl-3-methylimidazolium-based ionic liquids (ILs). Using angle-resolved X-ray photoelectron spectroscopy, we demonstrate that the degree of surface enrichment strongly decreases with increasing temperature for all the studied ILs. For ILs with the same cation, but different anions, [C8C1Im]Br, [C8C1Im][TfO] and [C8C1Im][Tf2N], no significant differences of the temperature-induced partial loss of surface enrichment are found. Measurements for [C4C1Im][TfO], [C8C1Im][TfO] and [C18C1Im][TfO] indicate a small effect of the chain length. For [C18C1Im][TfO], a continuous decrease of alkyl surface enrichment is found with increasing temperature, with no abrupt changes at the phase-transition temperature from the smectic A to the isotropic phase, indicating that the surface enrichment is not affected by this phase transition. 相似文献
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Paul Bendig Florian Hägele Walter Vetter 《Analytical and bioanalytical chemistry》2013,405(23):7485-7496
Food and contaminated indoor environments are the most relevant sources of human exposure to polyhalogenated chemicals. This study analyzed for the first time fat residues in kitchen hoods for contaminations with polyhalogenated compounds. A wide range of contaminants was detected in all kitchen hoods (n?=?15) and most of them could be quantified. Between 0.2 and 18 μg polyhalogenated chemicals/g fat were detected, with chlorinated paraffins being the most relevant contaminant group. Aside from the chlorinated paraffins, each kitchen hood fat sample showed a distinct fingerprint. A wide range of old and current-use brominated flame retardants were also detected in the samples. In addition to these contaminants originating from their use in indoor equipment, residues of organochlorine pesticides and semi-volatile halogenated natural products verified that cooking of food, accompanied with the release of contaminants from the heated food, was another relevant source of contamination. Re-analyses of two samples after 3 months only resulted in small variations in contaminant pattern and concentrations. Therefore, fat from kitchen hoods is proposed as an easily accessible matrix to assess contamination of these hazardous polyhalogenated chemicals. Figure
Picture of a kitchen hood and its filter. The fat collected from kitchen hood filters contained plenty of polyhalogenated chemicals 相似文献