Mechanische Denaturierung von Hochpolymeren in Lösung. 33. Mitt. Einfluß von Antischaumreagentien auf die fließinduzierte Kristallisation von Polyvinylalkohol aus dessen wällriger Lösung

Ohne Zusammenfassung     

Radical C?H Functionalization of Heteroarenes under Electrochemical Control

Electrochemical reactions are shown to be effective for the C H functionalization of a number of heterocyclic substrates that are recalcitrant to conventional peroxide radical initiation conditions. Monitoring reaction progress under electrochemical conditions provides mechanistic insight into the C H functionalization of a series of heterocycles of interest in medicinal chemistry.     

Development of the 8-aza-3-bromo-7-hydroxycoumarin-4-ylmethyl group as a new entry of photolabile protecting groups

A significant substitution effect of the position of the bromo group on the photosensitivity of the 8-azacoumarin chromophore leads to the development of a highly photosensitive 8-aza-3-bromo-7-hydroxycoumarin-4-ylmethyl (aza-3-Bhc) group that shows excellent photolytic efficiency and hydrophilicity with long-wavelength absorption maxima. The newly identified aza-3-Bhc group can be applied to caged glutamates for ester-type and carbamate-type protections of carboxyl and amino functionalities.     

Alternative two‐step matrix application method for imaging mass spectrometry to avoid tissue shrinkage and improve ionization efficiency

Mass spectrometry (MS) was used to measure the concentrations of drug and biological compounds in plasma and tissues. Matrix‐assisted laser desorption/ionization (MALDI) imaging MS (IMS) has recently been applied to the analysis of localized drugs on biological tissue surfaces. In MALDI‐IMS, matrix application process is crucial for successful results. However, it is difficult to obtain homogeneous matrix crystals on the tissue surface due to endogenous salts and tissue surface heterogeneity. Consequently, the non‐uniform crystals degrade the quality of the spectrum and likely cause surface imaging artifacts. Furthermore, the direct application of matrix solution can cause tissue shrinkage due to the organic solvents. Here, we report an alternative two‐step matrix application protocol which combines the vacuum deposition of matrix crystals and the spraying of matrix solution to produce a homogeneous matrix layer on the tissue surface. Our proposed technique can also prevent cracking or shrinking of the tissue samples and improve the ionization efficiency of the distributed exogenous material. Copyright © 2013 John Wiley & Sons, Ltd.     

A Payne�CRayner Type Inequality for the Robin Problem on Arbitrary Minimal Surfaces in {\mathbb{R}^N}

We prove a Payne?CRayner type inequality for the first eigenfunction of the Laplacian with Robin boundary condition on any compact minimal surface with boundary in ${\mathbb{R}^N}$ . We emphasize that no topological condition is necessary on the boundary.