Platinum‐Promoted Ga/Al2O3 as Highly Active,Selective, and Stable Catalyst for the Dehydrogenation of Propane

A novel catalyst material for the selective dehydrogenation of propane is presented. The catalyst consists of 1000 ppm Pt, 3 wt % Ga, and 0.25 wt % K supported on alumina. We observed a synergy between Ga and Pt, resulting in a highly active and stable catalyst. Additionally, we propose a bifunctional active phase, in which coordinately unsaturated Ga³⁺ species are the active species and where Pt functions as a promoter.     

Efficient bifunctional gallium-68 chelators for positron emission tomography: tris(hydroxypyridinone) ligands

A new tripodal tris(hydroxypyridinone) bifunctional chelator for gallium allows easy production of (68)Ga-labelled proteins rapidly under mild conditions in high yields at exceptionally high specific activity and low concentration.     

Role of buffer concentration and applied voltage in obtaining a good separation in planar electrochromatography

Planar electrochromatography is performed by applying an electric field across a thin layer chromatography (TLC) plate. In addition to electroosmotic flow in the axial direction, there is also flow to the surface of the TLC layer, and this can substantially degrade the quality of separation. This effect is offset by Joule heating which causes evaporation of liquid from the layer surface, and which under some conditions causes degradation of separation quality by excessive drying of the layer. It is shown that pH, buffer concentration, and applied voltage control the balance between liquid being driven to the surface and liquid evaporating from the surface due to Joule heating. Conditions are discussed which result in good separation quality, or in separations degraded by either excessive wetting or drying of the layer. The above separations were performed at constant voltage. A chromatogram is presented that shows that a good separation is also obtained at constant power, i.e. under conditions where there is a constant amount of Joule heating.     

Biomolecular DNP‐Supported NMR Spectroscopy using Site‐Directed Spin Labeling

Dynamic nuclear polarization (DNP) has been shown to greatly enhance spectroscopic sensitivity, creating novel opportunities for NMR studies on complex and large molecular assemblies in life and material sciences. In such applications, however, site‐specificity and spectroscopic resolution become critical factors that are usually difficult to control by current DNP‐based approaches. We have examined in detail the effect of directly attaching mono‐ or biradicals to induce local paramagnetic relaxation effects and, at the same time, to produce sizable DNP enhancements. Using a membrane‐embedded ion channel as an example, we varied the degree of paramagnetic labeling and the location of the DNP probes. Our results show that the creation of local spin clusters can generate sizable DNP enhancements while preserving the intrinsic benefits of paramagnetic relaxation enhancement (PRE)‐based NMR approaches. DNP using chemical labeling may hence provide an attractive route to introduce molecular specificity into DNP studies in life science applications and beyond.