Dimensions of triangulated categories via Koszul objects

Lower bounds for the dimension of a triangulated category are provided. These bounds are applied to stable derived categories of Artin algebras and of commutative complete intersection local rings. As a consequence, one obtains bounds for the representation dimensions of certain Artin algebras.     

A selective inhibitor and probe of the cellular functions of Jumonji C domain-containing histone demethylases

Histone methylations are important chromatin marks that regulate gene expression, genomic stability, DNA repair, and genomic imprinting. Histone demethylases are the most recent family of histone-modifying enzymes discovered. Here, we report the characterization of a small-molecule inhibitor of Jumonji C domain-containing histone demethylases. The inhibitor derives from a structure-based design and preferentially inhibits the subfamily of trimethyl lysine demethylases. Its methyl ester prodrug, methylstat, selectively inhibits Jumonji C domain-containing his-tone demethylases in cells and may be a useful small-molecule probe of chromatin and its role in epigenetics.     

Nanoscopic Visualization of Cross‐Linking Density in Polymer Networks with Diarylethene Photoswitches

The in situ nanoscopic imaging of soft matter polymer structures is of importance to gain knowledge of the relationship between structure, properties, and functionality on the nanoscopic scale. Cross‐linking of polymer chains effects the viscoelastic properties of gels. The correlation of mechanical properties with the distribution and amount of cross‐linkers is relevant for applications and for a detailed understanding of polymers on the molecular scale. We introduce a super‐resolution fluorescence‐microscopy‐based method for visualizing and quantifying cross‐linker points in polymer systems. A novel diarylethene‐based photoswitch with a highly fluorescent closed and a non‐fluorescent open form is used as a photoswitchable cross‐linker in a polymer network. As an example for its capability to nanoscopically visualize cross‐linking, we investigate pNIPAM microgels as a system known with variations in internal cross‐linking density.     

Zur thermischen Zersetzung des Hg2Cl2 und Hg2Br2

Thermical Decomposition of Hg₂Cl₂ and Hg₂Br₂ The thermical decomposition of Hg₂Cl₂ and Hg₂Br₂ was proved by total pressure measurements in a membrane manometer. The decomposition according to Hg₂X_2,s = Hg_,g + HgX_2,g and their thermodynamic data were confirmed.     

Über die Phasenbreite von V2O5 im Temperaturbereich von 450°C bis 620°C

About the Homogeneity Range of V₂O₅ in the Temperature Range of 450°C to 620°C The influence of the deposition temperature T₁ on the homogeneity range of V₂O₅-crystalls was investigated by using a solid electrolyte cell. The deviation x in V₂O_5–x from the stoichiometric composition was obtained with: x = 0.0066 at T₁ = 450°C up to x = 0.0326 at T₁ = 620°C.     

Untersuchungen zum System Bi2O3/BiI3

Investigations on the System Bi₂O₃/BiI₃ The temperature functions of decomposition pressures of the ternary compounds on the quasibinary line Bi₂O₃/BiI₃ were determined by total pressure measurements and mass spectrometry. The barogram of the system was constructed and the melting diagram precised. The enthalpies of formation and the standard entropies of the solid phases were derived from the decomposition functions: (Values see Inhaltsübersicht).     

Structural and mechanistic studies on γ-butyrobetaine hydroxylase

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Highlights? Crystal structure of γ-butyrobetaine hydroxylase in complex with substrate and inhibitor ? N-terminal Zn-binding domain involved in dimerization ? The clinically used inhibitor, THP, is also a substrate for BBOX ? BBOX catalyzed rearrangement reaction     

Interaction between oppositely charged polyelectrolytes in aqueous solution

Oppositely charged polyelectrolytes interact in solution, forming polyelectrolyte complexes, which often appear as gel-like precipitates. This kind of complex formation was studied by means of calorimetric and rheological measurements. The enthalpy effects, though being fairly small, give some information about the binding strength of counterions to the macroion. We studied the system poly(p-styrene sulfonate)/poly(trimethylammonium-2-ethyl methacrylate) (PSS-PTMA), varying systematically the low molar mass counterions of PSS. In every case, the maximum of enthalpy was found around a 1:1 (mol:mol monomer units) composition of the complexes, with the shape of enthalpy versus composition-curve indicating a stoichiometric interaction. The maximum enthalpy decreased with increasing atomic mass of the counterion when the alkaline metal salts of PSS were used and no change was made on the side of the cationic polyelectrolyte. The salts of the alkaline earth metals gave a distinctly higher enthalpy. On the contrary, viscosity measurements showed a very broad minimum as a function of composition, indicating that the formation of non-stoichiometric complexes is also occurring. The conclusion of these observations is that the complex formation is stoichiometric with respect to the monomeric units, but not necessarily stoichiometric with respect to the entire macromolecules.     

Beiträge zur Chemie der Oxidhalogenide von Molybdän und Wolfram. VI. Thermische Zersetzung von MoCl3 und MoOCl2

The temperature dependence of the thermal decay of α-MoCl₃ was determined and the entropies of MoCl₃ and MoCl₂ calculated. The decomposition behaviour of MoOCl₂ under equilibrium conditions may be described by the equation The decomposition reactions 6 MoOCl₂,s = Mo + MoO₂ + 4 MoOCl₃,g has only inferior importance. From the results the enthalpy and entropy values of MoOCl₂ are derived (data see “Inhaltsübersicht”).     

Investigations on the homogeneity of single crystals of materials with variable composition grown by chemical transport reactions

To investigate the problem of homogeneity in crystals grown by chemical transport reactions (CTR) solid solutions Fe_1-yCo_yS, Fe_1-yNi_yS, and Zn_1-yCo_yO were choosen as model substances. Relative concentration profiles of Co and Ni, respectively, were measured by electron-probe microanalysis and light absorption (in Zn_1-yCo_yO only). No significant deviations from homogeneity were found for Fe_1-yMe_yS, whereas in Zn_1-yCo_yO the Co contents increase in the growth direction. A qualitative explanation due to different diffusivities in the solids can be given.