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Der so genannte SCILL-Katalysator (englisch: solid catalyst with ionic liquid layer) beschreibt ein neues, äußerst erfolgreiches Konzept im Bereich der heterogenen Katalyse. Hierbei besteht die Grundidee darin, die Selektivität eines Katalysators durch die Beladung mit ionischen Flüssigkeiten drastisch zu erhöhen. In dieser Arbeit zeigen wir, dass das Konzept auf die Elektrokatalyse übertragbar ist und zur selektiven Umsetzung von organischen Verbindungen genutzt werden kann. Bei der hier untersuchten Elektrooxidation von 2,3-Butandiol können zwei Produkte entstehen. Das einfach oxidierte Acetoin und das zweifach oxidierte Diacetyl. Durch die Zugabe einer ionischen Flüssigkeit (1-Ethyl-3-methyl-imidazolium-trifluormethansulfonat, [C2C1Im][OTf]) kann die Selektivität des Katalysators zu Gunsten der Acetoinbildung drastisch erhöht werden. Der zugrundeliegende Mechanismus wurde dabei spektroskopisch in situ untersucht: Die Adsorption des Anions der ionischen Flüssigkeit verhindert die Wasseraktivierung. Dies unterbindet den zweiten Oxidationsschritt vom Acetoin zum Diacetyl und erhöht damit die Selektivität. Unsere Studie zeigt das große Potential elektrochemischer SCILL-Katalysatoren für die selektive Umsetzung von organischen Verbindungen.

Acidic supported ionic liquid phase catalysts were investigated for the synthesis of oxymethylene dimethyl ethers (OMEs). The application of OME1 and trioxane for the gas-phase synthesis of higher OMEs and in particular the generation of OMEn with n higher than 3 was successfully demonstrated. Raising the pressure led to an increase in the conversion of OME1 and to higher selectivity for higher molecular weight OMEs. Furthermore, a correlation between the ionic liquid’s acidity and the catalytic activity was shown with higher acidity leading to higher conversion of trioxane and OME1. Moreover, successful long-term operation for more than 200 h time on stream has been demonstrated with good catalyst system stability.

Four satellite-based snow products are evaluated over the Tibetan Plateau for the 2007–2010 snow seasons. The Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua snow cover daily L3 Global 500-m grid products (MOD10A1 and MYD10A1), the National Oceanic and Atmospheric Administration Interactive Multisensor Snow and Ice Mapping System (IMS) daily Northern Hemisphere snow cover product and the Advanced Microwave Scanning Radiometer – Earth Observing System Daily Snow Water Equivalent were validated against Thematic Mapper (TM) snow cover maps of Landsat-5 and meteorological station snow depth observations. The overall accuracy of MOD10A1, MYD10A1 and IMS is higher than 91% against stations observations and than 79% against Landsat TM images. In general, the daily MODIS snow cover products show better performance than the multisensor IMS product. However, the IMS snow cover product is suitable for larger scale (~4km) analysis and applications, with the advantage over MODIS to allow for mitigation for cloud cover. The accuracy of the three products decreases with decreasing snow depth. Overestimation errors are most common over forested regions; the IMS and Advanced Microwave Scanning Radiometer – Earth Observing System Snow Water Equivalent products also show poorer performance that the MODIS products over grassland. By identifying weaknesses in the satellite products, this study provides a focus for the improvement of snow products over the Tibetan plateau. The quantitative evaluation of the products proposed here can also be used to assess their relative weight in data assimilation, against other data sources, such as modelling and in situ measurement networks. Copyright © 2015 John Wiley & Sons, Ltd.

LSECtin, a novel member of the C-type lectin DC-SIGN family, not only acts as an attachment factor for pathogens, but also recognizes "endogenous" activated T cells. The endogenous ligands of LSECtin, however, have remained unclear. In this study, we identified CD44 on Jurkat T cells as a candidate ligand of LSECtin, and confirmed the specific interaction between LSECtin and CD44. Moreover, we showed that LSECtin selectively bound CD44s, CD44v4 and CD44v8-10 by screening a series of typical CD44 isoforms. By deletion of the carbohydrate-recognition domain region and mutation of crucial amino acids involved in carbohydrate-recognition of LSECtin and by inhibition of the N-linked glycosylation of CD44, we further demonstrated that the interaction between CD44 and LSECtin is dependent on protein-glycan recognition. Our findings indicate that CD44 is the first identified endogenous ligand of LSECtin, and similarly, that LSECtin is a novel ligand of CD44. These findings provide important new perspectives on the biology of both LSECtin and CD44 in the immune system.