Preparation of nanocrystalline VO<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript> by high-energy ball milling

We report high-energy milling of macrocrystalline nonstoichiometric cubic vanadium monoxide (VO _y ) powder in a planetary ball mill lined with stabilized zirconia. The results indicate that milling of macrocrystalline VO _y powder at 500 rpm for more than 2 h considerably broadens diffraction line profiles, with no changes in the crystal structure of the vanadium monoxide, VO_1.00. Microstructural examination of vanadium monoxide powder by high-resolution scanning electron microscopy and X-ray diffraction indicates that high-energy ball milling can be used to produce vanadium monoxide powder with an average crystallite size within 23 nm.     

Structure oriented library design in gas phase oxidation catalysis

Structure oriented screening techniques are discussed with regard to their usefulness and applicability in catalyst screening in research projects with different degrees of exploratory character. Structure oriented screening approaches were applied to build libraries for two target reactions in two case studies presented in this paper one challenging exploratory ammon-oxidation reaction for the conversion of C₆-feedstocks to adipodinitrile precursors with currently no relevant useful materials and no technical solution known. In this study the structure driven approach helped to identify lead structures for the conversion. The second case study focuses on the oxidation of acrolein and methacrolein to the corresponding unsaturated acids. Here technical catalyst candidate materials are known and are applied in the actual industrial applications. Therefore, the focus of the second case study is to find a superior material or alternative candidate materials with improved properties with this research strategy. For both case studies the effectiveness of the structure based approach is evaluated and put into perspective with state of the art library design and research strategies in high throughput experimentation and combinatorial catalysis.     

The Pro-Inflammatory Deletion Allele of the NF-κB1 Polymorphism Is Characterized by a Depletion of Subunit p50 in Sepsis

The functionally important NF-κB1 promoter polymorphism (−94ins/delATTG) significantly shapes inflammation and impacts the outcome of sepsis. However, exploratory studies elucidating the molecular link of this genotype-dependent pattern are lacking. Accordingly, we analyzed lipopolysaccharide-stimulated peripheral blood mononuclear cells from both healthy volunteers (n = 20) and septic patients (n = 10). All individuals were genotyped for the −94ins/delATTG NF-κB1 promoter polymorphism. We found a diminished nuclear activity of the NF-κB subunit p50 in ID/DD genotypes after 48 h of lipopolysaccharide stimulation compared to II genotypes (p = 0.025). This was associated with higher TNF-α (p = 0.005) and interleukin 6 concentrations (p = 0.014) and an increased production of mitochondrial radical oxygen species in ID/DD genotypes (p = 0.001). Although ID/DD genotypes showed enhanced activation of mitochondrial biogenesis, they still had a significantly diminished cellular ATP content (p = 0.046) and lower mtDNA copy numbers (p = 0.010) compared to II genotypes. Strikingly, these findings were mirrored in peripheral blood mononuclear cells taken from septic patients. Our results emphasize the crucial aspect of considering NF-κB subunits in sepsis. We showed here that the deletion allele of the NF-κB1 (−94ins/delATTG) polymorphism was associated with the lower nuclear activity of subunit p50, which, in turn, was associated with aggravated inflammation and mitochondrial dysfunction.     

Influence of the degree of order and nonstoichiometry on the microstructure and microhardness of titanium monoxide

The influence of the degree of order and nonstoichiometry on the microstructure of TiO _y titanium monoxide has been studied. The microstructure of substoichiometric, stoichiometric, and superstoichiometric titanium monoxide samples has been found to be determined by the presence of various ordered phases, which nucleate and grow in a matrix consisting of the high-temperature, cubic phase. The microhardness of titanium monoxide has been shown to depend on both nonstoichiometry and the degree of order, ranging from 9.9 to 14.0 GPa. The microhardness of the ordered monoxide exceeds that of the disordered monoxide, which is due to the formation of domains of an ordered phase, which hinder dislocation motion.     

An unusual chemical reactivity of Sm site adenosines strongly correlates with proper assembly of core U snRNP particles

The small nuclear ribonucleoprotein particles (snRNP) U1, U2, U4, and U5 contain a common set of eight Sm proteins that bind to the conserved single-stranded 5'-PuAU3-6GPu-3' (Sm binding site) region of their constituent U snRNA (small nuclear RNA), forming the Sm core RNP. Using native and in vitro reconstituted U1 snRNPs, accessibility of the RNA within the Sm core RNP to chemical structure probes was analyzed. Hydroxyl radical footprinting of in vitro reconstituted U1 snRNP demonstrated that riboses within a large continuous RNA region, including the Sm binding site, were protected. This protection was dependent on the binding of the Sm proteins. In contrast with the riboses, the phosphate groups within the Sm core site were accessible to modifying reagents. The invariant adenosine residue at the 5' end, as well as an adenosine two nucleotides downstream of the Sm binding site, showed an unexpected reactivity with dimethyl sulfate. This novel reactivity could be attributed to N7-methylation of the adenosine and was not observed in naked RNA, indicating that it is an intrinsic property of the RNA- protein interactions within the Sm core RNP. Further, this reactivity was observed concomitantly with formation of the Sm subcore intermediate during Sm core RNP assembly. As the Sm subcore can be viewed as the commitment complex in this assembly pathway, these results suggest that the peculiar reactivity of the Sm site adenosine bases may be diagnostic for proper assembly of the Sm core RNP. Consistent with this idea, a strong correlation was found between the unusual N7-A methylation sensitivity of the Sm core RNP and its ability to be imported into the nucleus of Xenopus laevis oocytes.     

Investigation of NH3 Influence on Adsorptive H2S Removal from Biogas for Solid Oxide Fuel Cell Application

The generation of electrical energy from biogas is state of the art. One option is the application of fuel cells for generating electrical energy. Due to their construction, the materials used and their mode of operation, solid oxide fuel cells (SOFCs) are particularly suitable. The primary problem in the operation of SOFCs using biogas is H₂S. The goal of this work is to investigate the possible effects of ammonia on different sorbents that have already successfully been used for the desulfurization of biogas. The H₂S adsorption capacity of four commercially available sorbents in the presence of NH₃ was investigated as well as the influence of an upstream NH₃ removal. The CuO‐MnO‐based sorbent showed the best performance related to sulfur uptake.     

Patterned immobilisation of silicon dioxide nanoparticles on the surface of a photosensitive polymer

A photosensitive co-polymer of styrene and 4-vinylbenzyl thiocyanate was synthesised and employed for the immobilisation of aminofunctionalised silica nanoparticles (SiO₂-NP) at the polymer surface. Upon UV irradiation of the co-polymer, isothiocyanate groups are generated by a photo-isomerisation reaction of the thiocyanate groups. The silica nanoparticles were selectively immobilised in irradiated areas by immersing the illuminated polymer surface in a solution of SiO₂-NP. Depending on the time of immersion and the nanoparticle concentration, different amounts of silica can be deposited in the irradiated areas, whilst no immobilisation of SiO₂-NP is observed in the non-irradiated areas. By using photolithographic methods, patterned silica structures (μm scale) were produced on the polymer surface. The SiO₂-NP covered surfaces are of potential interest to generate protective surface layers and to carry out further functionalisation reactions of the immobilised SiO₂-NP particles.