2018, Mosrati, Jawaher, Atia, Hanan, Eckelt, Reinhard, Lund, Henrik, Agostini, Giovanni, Bentrup, Ursula, Rockstroh, Nils, Keller, Sonja, Armbruster, Udo, Mhamdi, Mourad

Recently, great attention has been paid to Ceria-based materials for selective catalytic reduction (SCR) with NH3 owing to their unique redox, oxygen storage, and acid-base properties. Two series of bimetallic catalysts issued from Titania modified by Ce and Nb were prepared by the one-step sol-gel method (SG) and by the sol-gel route followed by impregnation (WI). The resulting core-shell and bulk catalysts were tested in NH3-SCR of NOx. The impregnated Nb5/Ce40/Ti100 (WI) catalyst displayed 95% NOx conversion at 200 °C (GHSV = 60,000 mL·g−1·h−1, 1000 ppm NOx, 1000 ppm NH3, 5% O2/He) without forming N2O. The catalysts were characterized by various methods including ICP-OES, N2-physisorption, XRD, Raman, NH3-TPD, DRIFTS, XPS, and H2-TPR. The results showed that the introduction of Nb decreases the surface area and strengthens the surface acidity. This behavior can be explained by the strong interaction between Ceria and Titania which generates Ce-O-Ti units, as well as a high concentration of amorphous or highly dispersed Niobia. This should be the reason for the excellent performance of the catalyst prepared by the sol-gel method followed by impregnation. Furthermore, Nb5/Ce40/Ti100 (WI) has the largest NH3 adsorption capacity, which is helpful to promote the NH3-SCR reaction. The long-term stability and the effect of H2O on the catalysts were also evaluated.

2018, Vakkeel, Roshna, Aleeza, Farrukh, del Campo, Aranzazu

In order to study how dynamic changes of α5β1 integrin engagement affect cellular behaviour, photoactivatable derivatives of α5β1 specific ligands are presented in this article. The presence of the photoremovable protecting group (PRPG) introduced at a relevant position for integrin recognition, temporally inhibits ligand bioactivity. Light exposure at cell-compatible dose efficiently cleaves the PRPG and restores functionality. Selective cell response (attachment, spreading, migration) to the activated ligand on the surface is achieved upon controlled exposure. Spatial and temporal control of the cellular response is demonstrated, including the possibility to in situ activation. Photoactivatable integrin-selective ligands in model microenvironments will allow the study of cellular behavior in response to changes in the activation of individual integrins as consequence of dynamic variations of matrix composition.

2018, Koepler, Oliver, Jung, Nicole, Kraft, Angelina, Neumann, Janna, Auer, Sören, Bach, Felix, Bähr, Thomas, Engel, Thomas, Kettner, Carsten, Kowol-Santen, Johanna, Liermann, Johannes, Lipp, Anne, Porzel, Andrea, Razum, Matthias, Schlörer, Niels, Solle, Dörte, Winkler, Torsten

“Der stufenweise Aufbau einer Nationalen Forschungsdateninfrastruktur in Netzwerkform hat das Ziel, ein verlässliches und nachhaltiges Dienste-Portfolio zu schaffen, welches generische und fachspezifische Bedarfe des Forschungsdatenmanagements in Deutschland abdeckt.” Für das Fachgebiet Chemie ermöglicht eine solche nationale Forschungsdateninfrastruktur, öffentlich-finanzierte Forschungsdaten effizient zu erheben, standardisiert zu beschreiben, dauerhaft zu speichern und durch Persistent Identifier (PID) eindeutig referenzierbar und auffindbar zu machen. Sie unterstützt gemäß den Vorgaben des RfII die Reproduzierbarkeit und Nachnutzbarkeit der Daten zum Zwecke einer perpetuierten Wissensgenerierung. Mit der Reproduzierbarkeit von Forschungsergebnissen unterstützt eine solche Forschungsdateninfrastruktur den Peer Reviewing Prozess zur Förderung der wissenschaftlichen Selbstkontrolle und erhöht die Datenqualität, insbesondere in wissenschaftlichen Publikationen. Die NFDI4Chem ist ein gemeinschaftlicher Ansatz von Wissenschaftlern aus der Chemie, der Fachgesellschaft Gesellschaft Deutscher Chemiker und deren Fachgruppen, Einrichtungen aus der Forschungsförderung und Infrastruktureinrichtungen (Technische Informationsbibliothek). Eine Gruppe von Vertretern dieser Stakeholder hat sich Ende April 2018 zu einem Auftakttreffen “Fachgespräch NFDI4Chem” in Hannover getroffen. Dieses Papier fasst die Erkenntnisse des Fachgespräches zusammen. Weitere Stakeholder wie Verlage oder Datenbankanbieter sind im folgenden Diskurs willkommen.

2018, Höhne, Martha, Aluri, Bhaskar R., Spannenberg, Anke, Müller, Bernd H., Peulecke, Normen, Rosenthal, Uwe

The title compound, C24H22N2O2P2, contains a diphosphazane backbone, as well as a hydrazine entity. The P—N—P diphosphazane unit and the N-amine N atom are almost coplanar, and the O atoms of the Ph2P(O) units are oriented trans to each other with respect to the P...P axis. In the crystal, centrosymmetrically related mol­ecules are linked into dimers by pairs of N—H...O hydrogen bonds, forming rings of graph-set motif R22(10).

2018, Khan, Essak, Sankaran, Shrikrishnan, Paez, Julieta, Muth, Christina, Han, Mitchell, del Campo, Aránzazu

Hsp47 is a chaperone protein with a fundamental role in the folding, stability and intracellular transport of procollagen triple helices. A light-responsive Hsp47 recombinant protein, engineered to control in situ the production and assembly of cellular collagen is here demonstrated. This novel light-driven tool enables unprecedented fundamental studies of collagen biosynthesis and associated diseases.

2018, Kidd, Rich, Koch, Wolfram, Milne, James, Sens, Irina, Tegen, Sarah, Wilson, Emma, Henderson, Darla, Brennan, Marshall

In this post, the ChemRxiv Governing Board and Management Team describe the achievements of the past year and detail some of our plans for the future of ChemRxiv.

2018, Rohles, Christina Maria, Gläser, Lars, Kohlstedt, Michael, Gießelmann, Gideon, Pearson, Samuel, del Campo, Aránzazu, Becker, Judith, Wittmann, Christoph

In the present work, we established the bio-based production of glutarate, a carbon-5 dicarboxylic acid with recognized value for commercial plastics and other applications, using metabolically engineered Corynebacterium glutamicum. The mutant C. glutamicum AVA-2 served as a starting point for strain development, because it secreted small amounts of glutarate as a consequence of its engineered 5-aminovalerate pathway. Starting from AVA-2, we overexpressed 5-aminovalerate transaminase (gabT) and glutarate semialdehyde dehydrogenase (gabD) under the control of the constitutive tuf promoter to convert 5-aminovalerate further to glutarate. The created strain GTA-1 formed glutarate as a major product, but still secreted 5-aminovalerate as well. This bottleneck was tackled at the level of 5-aminovalerate re-import. The advanced strain GTA-4 overexpressed the newly discovered 5-aminovalerate importer NCgl0464 and formed glutarate from glucose in a yield of 0.27 mol mol−1. In a fed-batch process, GTA-4 produced more than 90 g L−1 glutarate from glucose and molasses based sugars in a yield of up to 0.70 mol mol−1 and a maximum productivity of 1.8 g L−1 h−1, while 5-aminovalerate was no longer secreted. The bio-based glutaric acid was purified to >99.9% purity. Interfacial polymerization and melt polymerization with hexamethylenediamine yielded bionylon-6,5, a polyamide with a unique structure.

2018, Salihovic, Miralem, Hüsing, Nicola, Bernardi, Johannes, Presser, Volker, Elsaesser, Michael S.

Mechanically reversible compressible resorcinol–formaldehyde (RF) aerogels can be converted into mechanically reversible compressible carbon aerogels (CA) by carbonization in an inert atmosphere. By incorporation of polystyrene spheres into the RF gels as a sacrificial template, it is possible to create macropores with controlled size within the carbon framework during carbonization. The resulting templated carbon aerogel shows enhanced mechanical flexibility during compression compared to pristine samples. In addition, the presence of hierarchical porosity provides a porous architecture attractive for energy storage applications, such as supercapacitors.