Nachweis fettl?slicher synthetischer Farbstoffe in Lebensmitteln und Cosmetica

Ohne Zusammenfassung     

Zur Bestimmung von Hydroxylgruppen

Ohne Zusammenfassung     

Mononuclear anionic formyl complexes; synthesis and properties

A series of kinetically unstable mononuclear anionic formyl complexes have been prepared by the action of Li(C₂H₅)₃BH on neutral metal carbonyl precursors. One of these, Li⁺[(CO)₄Mn(COC₆H₅)(CHO)]^?, is shown to decompose by a hydride transfer disproportionation mechanism involving the by-product (C₂H₅)₃B.     

Near-infrared photoluminescence from a plutonyl ion

We report the first example of photoluminescence from electronically excited states of the plutonyl ion. Discrete emission transitions were measured between 6000 and 10,200 cm(-1) from crystalline Cs2U(Pu)O2Cl4 cooled to 75 K following pulsed laser excitation at 628 nm. An excitation spectrum in the region of 15,000-16,500 cm(-1) is compared with 4.2 K plane-polarized absorption spectra reported by Gorshkov and Mashirov. Analysis of excited-state lifetime data suggests multiple relaxation pathways in the electronic structure of PuO2Cl4(2-).     

Lie powers and Witt vectors

In the study of Lie powers of a module V in prime characteristic p, a basic role is played by certain modules B _n introduced by Bryant and Schocker. The isomorphism types of the B _n are not fully understood, but these modules fall into infinite families , one family B(k) for each positive integer k not divisible by p, and there is a recursive formula for the modules within B(k). Here we use combinatorial methods and Witt vectors to show that each module in B(k) is isomorphic to a direct sum of tensor products of direct summands of the kth tensor power V ^{⊗ k} . To the memory of Manfred Schocker.     

A Set of Activity‐Based Probes to Visualize Human (Immuno)proteasome Activities

Proteasomes are therapeutic targets for various cancers and autoimmune diseases. Constitutively expressed proteasomes have three active sites, β1c, β2c, and β5c. Lymphoid tissues also express the immunoproteasome subunits β1i, β2i, and β5i. Rapid and simultaneous measurement of the activity of these catalytic subunits would assist in the discovery of new inhibitors, improve analysis of proteasome inhibitors in clinical trials, and simplify analysis of subunit expression. In this work, we present a cocktail of activity‐based probes that enables simultaneous gel‐based detection of all six catalytic human proteasome subunits. We used this cocktail to develop specific inhibitors for β1c, β2c, β5c, and β2i, to compare the active‐site specificity of clinical proteasome inhibitors, and to demonstrate that many hematologic malignancies predominantly express immunoproteasomes. Furthermore, we show that selective and complete inhibition of β5i and β1i is cytotoxic to primary cells from acute lymphocytic leukemia (ALL) patients.     

Novel silica stabilization method for the analysis of fine nanocrystals using coherent X‐ray diffraction imaging

High‐energy X‐ray Bragg coherent diffraction imaging (BCDI) is a well established synchrotron‐based technique used to quantitatively reconstruct the three‐dimensional morphology and strain distribution in nanocrystals. The BCDI technique has become a powerful analytical tool for quantitative investigations of nanocrystals, nanotubes, nanorods and more recently biological systems. BCDI has however typically failed for fine nanocrystals in sub‐100 nm size regimes – a size routinely achievable by chemical synthesis – despite the spatial resolution of the BCDI technique being 20–30 nm. The limitations of this technique arise from the movement of nanocrystals under illumination by the highly coherent beam, which prevents full diffraction data sets from being acquired. A solution is provided here to overcome this problem and extend the size limit of the BCDI technique, through the design of a novel stabilization method by embedding the fine nanocrystals into a silica matrix. Chemically synthesized FePt nanocrystals of maximum dimension 20 nm and AuPd nanocrystals in the size range 60–65 nm were investigated with BCDI measurement at beamline 34‐ID‐C of the APS, Argonne National Laboratory. Novel experimental methodologies to elucidate the presence of strain in fine nanocrystals are a necessary pre‐requisite in order to better understand strain profiles in engineered nanocrystals for novel device development.