Smart Surfaces: Heterogeneous Photo-Catalysis on TiO2 Based Coatings for De-pollution Purposes in Indoor and Outdoor Environments

Topics in Catalysis - Heterogeneous photocatalysis using semiconductors, e.g. TiO2 as photocatalyst is a promising technology for the degradation of environmental pollutants. Preliminary evidence...     

Ultra-low gas sensing utilizing metal oxide thin films

The structure, functionality and sensing response of metal oxide films is discussed with emphasis on ZnO and InO_x prepared by Aerosol Spray Pyrolysis in ambient atmosphere and DC Magnetron Sputtering techniques under vacuum. Optical, structural and electrical characterization techniques applied for the in-depth analysis of the film properties are described. Sensing response towards ozone is presented utilizing a conventional conductivity technique as well as surface acoustic wave (SAW) structures and devices. It is shown that sensing responses of extremely low ozone concentrations in the range of a few parts per billion (ppb), at room temperature (RT), may be obtained by appropriate control of the film nanostructure. It is also shown that InO_x employed as sensitive layer on top of surface acoustic wave structures can lead to strong frequency shifts for low concentrations of NO₂, H₂ and O₃ gases.     

Hydrogen storage in ordered and disordered phenylene-bridged mesoporous organosilicas

Novel hexagonal Periodic Mesoporous Organosilicas (PMOs) and Disordered Mesoporous Organosilicas (DMOs) were synthesized by hydrolysis of 1,4-bis(trialkoxylsilyl) benzene precursor in alkaline aqueous solutions of different alkyl-trimethyl ammonium cations and evaluated for their hydrogen storage capacity. The PMO materials exhibit regular hexagonal pore arrangement and specific surface area between 640 and 782 m² g⁻¹ whereas the DMO materials have specific surface area that lies between 650 and 910 m² g⁻¹. The storage capacity of the materials is discussed in terms of number of molecules per surface unit. The materials exhibit a reversible hydrogen excess surface adsorption capacity up to 2.10 wt% at 6 MPa and 77 K. DFT calculations were performed to define the binding strength of hydrogen with the pore walls indicated an interaction energy value of −0.55 Kcal mol⁻¹, higher than the interaction energy value of hydrogen with a single benzene or a benzene incorporated in the IRMOR-1 walls. Grand Canonical Monte Carlo (GCMC) simulations showed that no hydrogen molecule can be inserted inside the wall structure of the materials.     

Linear and cyclic porphyrin hexamers as near-infrared emitters in organic light-emitting diodes

Here we report organic light-emitting diodes incorporating linear and cyclic porphyrin hexamers which have red-shifted emission (λ(PL) = 873 and 920 nm, respectively) compared to single porphyrin rings as a consequence of their extended π-conjugation. We studied the photoluminescence and electroluminescence of blends with poly(9,9'-dioctylfluorene-alt-benzothiadiazole), demonstrating a high photoluminescence quantum efficiency of 7.7% for the linear hexamer when using additives to prevent aggregation and achieving high color purity near-infrared electroluminescence.     

19F NMR-Based Fragment Screening for 14 Different Biologically Active RNAs and 10 DNA and Protein Counter-Screens

We report here the nuclear magnetic resonance ¹⁹F screening of 14 RNA targets with different secondary and tertiary structure to systematically assess the druggability of RNAs. Our RNA targets include representative bacterial riboswitches that naturally bind with nanomolar affinity and high specificity to cellular metabolites of low molecular weight. Based on counter-screens against five DNAs and five proteins, we can show that RNA can be specifically targeted. To demonstrate the quality of the initial fragment library that has been designed for easy follow-up chemistry, we further show how to increase binding affinity from an initial fragment hit by chemistry that links the identified fragment to the intercalator acridine. Thus, we achieve low-micromolar binding affinity without losing binding specificity between two different terminator structures.     

Long-chain fatty acid uptake by skeletal muscle is impaired in homozygous,but not heterozygous,heart-type-FABP null mice

Previous studies with cardiac myocytes from homozygous heart-type fatty acid (FA)-binding protein (H-FABP)^−/− mice have indicated that this intracellular: receptor protein for long-chain FA is involved in the cellular uptake of these substrates. Based on the knowledge that muscle FA uptake is a process highly sensitive to regulation by hormonal and mechanical stimuli, we studied whether H-FABP would play a role in this regulation. A suitable model system to answer this question is provided by H-FABP^+/− mice, because in hindlimb muscles the content of H-FABP was measured to be 34% compared to wild-type mice. In these H-FABP^+/− skeletal muscles, just as in H-FABP^−/− muscles, contents of FA transporters, i.e., 43-kDa FABPpm and 88-kDa FAT/CD36, were similar compared to wild-type muscles, excluding possible compensatory mech-anisms at the sarcolemmal level. Palmitate uptake rates were measured in giant vesicles prepared from hindlimb muscles of H-FABP^−/−, H-FABP^+/− and H-FABP^+/+ mice. For comparison, giant vesicles were isolated from liver, the tissue of which expresses a distinct type of FABP (i.e., L-FABP). Whereas in H-FABP^−/− skeletal muscle FA uptake was reduced by 42–45%, FA uptake by H-FABP^+/− skeletal muscle was not different from that in wild-type mice. In contrast, in liver from H-FABP^−/− and from H-FABP^+/− mice, FA uptake was not altered compared to wild-type animals, indicating that changes in FA uptake are restricted to H-FABP expressing tissues. It is concluded that H-FABP plays an important, yet merely permissive, role in FA uptake into muscle tissues.