No abstract

Hierarchically three-dimensional (3D) porous ZnO architectures were synthesized by a template-free, economical hydrothermal method combined with subsequent calcination. First, a precursor of hierarchical basic zinc carbonate (BZC) nanostructures self-assembled by sheet-like blocks was prepared. Then calcination of the precursor produced hierarchically 3D porous ZnO architectures composed of interconnected ZnO nanosheets with high porosity resulting from the thermal decomposition of the precursor. The products were characterized by X-ray diffraction, Fourier tranform infrared spectroscopy, thermogravimetric-differential thermalgravimetric analysis, scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller N 2 adsorption-desorption analyses. Control experiments with variations in solvent and reaction time respectively revealed that ethanol was responsible for the formation of the BZC precursor, and the self-assembly of BZC nanosheets into hierarchically 3D architectures was highly dependent on the reaction time. Gas sensing tests showed that these hierarchically porous ZnO architectures were highly promising for gas sensor applications, as the gas diffusion and mass transportation in sensing materials were significantly enhanced by their unique structures. Moreover, it is believed that this solution-based approach can be extended to fabricate other porous metal oxide materials with a unique morphology or shape.

Porokeratosis (PK) is a heterogeneous group of keratinization disorders. No causal genes except MVK have been identified, even though the disease was linked to several genomic loci. Here, we performed massively parallel sequencing and exonic CNV screening of 12 isoprenoid genes in 134 index PK patients (61 familial and 73 sporadic) and identified causal mutations in three novel genes (PMVK, MVD, and FDPS) in addition to MVK in the mevalonate pathway. Allelic expression imbalance (AEI) assays were performed in 13 lesional tissues. At least one mutation in one of the four genes in the mevalonate pathway was found in 60 (98%) familial and 53 (73%) sporadic patients, which suggests that isoprenoid biosynthesis via the mevalonate pathway may play a role in the pathogenesis of PK. Significantly reduced expression of the wild allele was common in lesional tissues due to gene conversion or some other unknown mechanism. A G-to-A RNA editing was observed in one lesional tissue without AEI. In addition, we observed correlations between the mutations in the four mevalonate pathway genes and clinical manifestations in the PK patients, which might support a new and simplified classification of PK under the guidance of genetic testing.DOI: http://dx.doi.org/10.7554/eLife.06322.001

Polypyrrole-coated SnO 2 hollow spheres hybrid materials have been synthesized through an in situ polymerization of pyrrole monomers in the presence of preprepared SnO 2 hollow spheres. The hybrids were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), and thermogravimetric analysis (TG). Experimental data showed certain synergetic interaction existed in the hybrids, probably resulting in the enhanced thermal stability of polypyrrole coatings. Gas sensing tests showed that the hybrids possessed very fast response and high sensitivity to ammonia gas at room temperature, implying its potential application for gas sensors.

Small ZnO nanoclusters supported on dealuminated β zeolite were prepared and evaluated for catalyzing direct dehydrogenation of propane to propylene (PDH), exhibiting high catalytic performance. N2 sorption, XRD, TEM, 27Al and 28Si MAS NMR, IR, XRF, DR UV‐vis, XPS, and NH3‐TPD techniques were employed to characterize the physicochemical properties of this novel catalyst system. It is found that the Zn species can be accommodated in the vacant T‐atom sites of dealuminated β zeolite due to the reaction of aqueous zinc acetate solution with silanol groups, and thus, producing massive small ZnO nanoclusters as active phases in PDH. Additionally, dealuminated β zeolite can greatly depress side reactions attributable to the absence of strong acid sites, thereby guaranteeing high catalytic activity, propylene selectivity and stability. As a result, the optimal catalyst of 10 wt% Zn loaded on dealuminated β zeolite exhibits a high initial propane conversion of around 53 % and a superior propylene selectivity of about 93 % at a space velocity of 4000 cm3 gcat−1 h−1, together with the high stability and satisfactory reusability. This study may open a new way to design and synthesize highly active PDH catalysts with high selectivity and stability.