[dumb1224]

Not an expert in this field, but from their website https://www.hfnl.ustc.edu.cn/detail?id=23165 They seemed to have developed a vibration-based slicer scanner 'Blockface-VISoR' to scan 600μm 3d image but cut 400μm each time repeatly to reconstruct full 3d image. It says it's hydrogel treated sample.

P.S the visualisation tool to explore and navigate the slices is quite awesome too https://mesoanatomy.org/mesomouse/