Solid-phase photocatalytic degradation of polystyrene plastic with goethite modified by boron under UV-vis light irradiation

A novel photodegradable polyethylene-boron-goethite (PE-B-goethite) composite film was prepared by embedding the boron-doped goethite into the commercial polyethylene. The goethite catalyst was modified by boron in order to improve its photocatalytic efficiency under the ultraviolet and visible light irradiation. Solid-phase photocatalytic degradation of the PE-B-goethite composite film was carried out in an ambient air at room temperature under ultraviolet and visible light irradiation. The properties of composite films were compared with those of the pure PE films and the PE-goethite composite films through performing weight loss monitoring, scanning electron microscope (SEM) analysis, FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS). The photo-induced degradation of PE-B-goethite composite films was higher than that of the pure PE films and the PE-goethite composite films under the UV-irradiation, while there has been little change under the visible light irradiation. The weight loss of the PE-B-goethite (0.4 wt.%) composite film reached 12.6% under the UV-irradiation for 300 h. The photocatalytic degradation mechanism of the composite films was briefly discussed.     

Stepwise synthesis of RNA conjugates carrying peptide sequences for RNA interference studies

Oligoribonucleotide conjugates carrying nuclear localization peptide sequences at the 3′-end were prepared stepwise on a single support. The siRNA duplex carrying the nuclear localization peptide sequence at the 3′-end of the passenger strand has similar inhibitory properties as those of unmodified or cholesterol-modified RNA duplexes.