With RRC-OSEM and six iterations, four of the six spheres reached the recovery convergence; all spheres reached recovery convergence after nine iterations.
Observing from Table1, without silica shell, the shrinkage ratio of air spheres reached as high as 14.7%, close to the value reported elsewhere[12, 13].
The centers of the spheres were placed in the center of the pores, and their radii increased with a step size of 1 voxel length (5.9 µm), until the spheres reached the surface of the sand and celestite grains.
As excepted, the hydrogen production rate of ZnO@TiO2 hollow spheres reached to 0.152 mmol h−1 g−1, higher than the 0.039 mmol h−1 g−1 of ZnO and 0.085 mmol h−1 g−1 of TiO2 (Fig. 5b).
However, when spheres reached their maximum dimensions, these levels rapidly declined (Figure S4A).
The ability of cells forming spheres to generate novel spheres over successive passages was evaluated through seeding the individual cells at low densities (104 cellstartingstarting when the spheres reached a minimum 100 µm diameter as described [32].
When spheres reached 0.7 mm in diameter, they were chopped up to passage 3 with a McIlwain tissue chopper.
The sphere culture media was changed every 48 h until the majority of spheres reached 100-400 μm in diameter (approximately 7 days).
When the spheres reached a size at which their cores turned dark (70 100 μm), the cultures were trypsinized to single cells (Suppl. Fig. 1).
