We report the strategy of using the cationic surfactant cetyltrimethylammonium bromide (CTAB) and amino acid L-histidine (His) as co-templates to produce hierarchical ZIF-8 in an aqueous system at room temperature. The hierarchical ZIF-8 had both meso- and microporous structure, resulting in a high mesopore volume as well as specific surface area which can be controlled by the synthesis conditions. We put forward the hypothesis for the formation of a mesoporous structure and the enhancement of the porosity of ZIF-8 that the histidine plays a key role on the stabilization of CTAB micelles and avoiding the production of unexpected by-products therefore promotes the fabrication of pure phase ZIF-8 containing the mesopores interconnected with micropores. The prepared hierarchical ZIF-8 exhibited an excellent performance as a new kind of porous absorbent for efficient removal of the toxic arsenate.

A general one-step in situ pyrolysis route for the construction of metal-organic frameworks encapsulating superparamagnetic γ-Fe2O3NPs dispersed in the confined cavities of MOFs homogeneously is described. The integration of γ-Fe2O3 NPs or clusters into MOFs can endow these porous materials with superparamagnetic element. By the combination of the thermal stability of MOFs and pyrolysis of metal triacetylacetonate complex at matched conditions, the porous structure of MOFs are well maintained while the size-induced superparamagnetic property of nano γ-Fe2O3 is obtained. As a proof of concept, both the γ- Fe2O3@ZIF-8 and γ-Fe2O3@MIL-53(Al) were successfully prepared, and the latter was chosen to demonstrate its potential drug delivery as a magnetic MOF.

No abstract

Wolfiporia cocos Ryvarden et Gilbertson is a saprophytic fungus in the Basidiomycetes. Its dried sclerotium is widely used as a traditional crude drug in East Asia. Especially in China, the dried sclerotium is regarded as the silver of the Chinese traditional drugs, not only for its white color, but also its medicinal value. Furthermore, triterpenoids from W. cocos are the main active compounds with antitumor and anti-inflammatory activity. Biosynthesis of the triterpenoids has rarely been researched. In this study, the de novo sequencing of the mycelia and sclerotia of W. cocos were carried out by Illumina HiSeq 2000. A total of 3,484,996,740 bp from 38,722,186 sequence reads of mycelia, and 3,573,921,960 bp from 39,710,244 high quality sequence reads of sclerotium were obtained. These raw data were assembled into 60,354 contigs and 40,939 singletons, and 56,938 contigs and 37,220 singletons for mycelia and sclerotia, respectively. The transcriptomic data clearly showed that terpenoid biosynthesis was only via the MVA pathwayin W. cocos. The production of total triterpenoids and pachymic acid was examined in the dry mycelia and sclerotia. The content of total triterpenoids was 5.36% and 1.43% in mycelia and sclerotia, respectively, and the content of pachymic acid was 0.458% and 0.174%. Some genes involved in the triterpenoid biosynthetic pathway were chosen to be verified by qRT-PCR. The unigenes encoding diphosphomevalonate decarboxylase (Unigene 20430), farnesyl diphosphate synthase (Unigene 14106 and 21656), hydroxymethylglutaryl-CoA reductase (NADPH) (Unigene 6395_All) and lanosterol synthase (Unigene28001_All) were upregulated in the mycelia stage. It is likely that expression of these genes influences the biosynthesis of triterpenoids in the mycelia stage.

Megacities are facing serious water pollution problems due to urbanization, rapid population growth and economic development. Water is an essential resource for human activities and socio-economic development and water quality in urban settings has important implications for human and environmental health. Urbanization and lack of sewerage has left the water in Jakarta, Indonesia in a heavily polluted condition. Rigorous assessment of urban water quality is necessary to understand the factors controlling water quality conditions. We use trend analysis to assess the current water quality conditions in Jakarta, focusing on Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), and Total Suspended Solids (TSS). In most monitoring stations analyzed, BOD and TSS concentrations have decreased over time, but from large starting concentrations. DO in most monitoring stations has increased. Although Jakarta’s water quality has shown some improvement, it remains heavily impaired. The average value of BOD is low in upper stream stations compared to middle and lower stream stations. BOD and TSS trends of some water quality stations in middle and lower streams show increasing trends. Cluster analysis results suggest three groups for BOD and TSS, and four groups for DO. Understanding water quality conditions and factors that control water quality suggest strategies for improving water quality given current trends in climate, population growth and urban development. Results from this study suggest research directions and management strategies to address water quality challenges.

Effective deposition of MOFs on "inert" solid surfaces is very challenging. In this work, we found that polydopamine, which can be facilely and tightly formed on any types as well as any forms of solid surfaces, could be used as an effective nucleation center for MOF deposition. Based on this finding, various MOFs were successfully deposited onto nanofibrous polymer membranes, especially the commercially available "inert" ones, affording hierarchically structured porous films.

No abstract

Molecular imprinting is an important tool for generating synthetic receptors with specific recognition sites.The resulting artificial receptor has been extensively used in areas that require molecular recognition.Nevertheless, various imprinted materials synthesized using conventional imprinting protocols have low binding capacities and slow binding kinetics because of difficulty in extracting the original templates and high resistance to mass transfer. The combination of molecular imprinting and nanostructured materials is expected to overcome such difficulties. In this work, template molecules were attached onto the electrospun fibers and by using electrospun nanofibers and attached molecules as sacrificial templates, surface molecularly imprinted membranes with bi-, tri-or tetramodal pore structures were fabricated in the absence or presence of SiO 2 nanoparticles in the molecular imprinting precursor. As a demonstration, bovine serum albumin (BSA) and hemoglobin from bovine blood (bHb) were chosen as template molecules and imprinted electrospun affinity membranes with multimodal pore structures were successfully fabricated for protein separation. Compared with the membrane with a bi-or trimodal pore structure, the tetramodal membrane, which consisted of tubule channels, imprinted nanocavities on the inner surface of tube wall, gaps between tubes and pores in the tube wall left by SiO 2 nanoparticles, exhibited a very favorable recognition property and efficient separation toward the template protein molecules in aqueous medium. In a two-protein system, the tetramodal membrane has also shown a very high specific recognition for the template proteins over the non-template proteins. Dynamic binding tests and reusability tests further revealed that tetramodal porous membranes had excellent selectivity, faster binding kinetics and good regenerability. These results indicate that in conjugation with the surface molecular imprinting technique the use of electrospun fibers as sacrificial templates could be used as an efficient strategy for development of high performance affinity membrane materials.