We developed a unique strategy for fabricating hierarchically structured (nanoparticles-in-beads) Zn2SnO4 beads (ZTO-Bs), which were then used to produce ternary metal oxide-based dye-sensitized solar cells (DSSCs). DSSCs were fabricated using the ZTO-Bs as the photoelectrodes and highly absorbable organic dyes as the sensitizers. The DSSCs based on the ZTO-Bs and the organic dyes (SJ-E1 and SJ-ET1) exhibited the highest performance ever reported for DSSCs with ternary metal oxide-based photoelectrodes. The optimized DSSCs exhibited a power conversion efficiency of 6.3% (VOC of 0.71 V, JSC of 12.2 mA cm−2, FF of 0.72), which was much higher than that for DSSCs with conventional ZTO-NPs-based photoelectrodes or those based on the popular ruthenium-based dye, N719. The unique morphology of the ZTO-Bs allowed for improvements in dye absorption, light scattering, electrolyte penetration, and the charge recombination lifetime, while the organic dyes resulted in high molar absorbability.

Celastrol, a quinone methide triterpenoid from the Chinese medicinal root bark of Tripterygium wilfordii, possesses beneficial therapeutic properties and affects numerous cellular pathways. Recently, structure and activity relation studies based on celastrol semi-synthetic derivatives have contributed greatly to our understanding of its mechanism of action and cellular targets. These modifications have resulted in better activity and improvement of the pharmacokinetic properties of celastrol. This review will mainly cover advances in the structural modifications of celastrol at the C-20 carboxylic acid functionality, alterations of the A ring, and modifications at C-6.