"When we publish, we focus on quantity over quality,” says a physics lecturer from a prominent Beijing university.

Tricks used by “paper mills” — the outfits paid to fabricate scientific studies — have become wearily familiar.

They range from clear duplication — the same images of cell cultures on microscope slides copied across numerous, unrelated studies — to more subtle tinkering. Sometimes an image is rotated “to try to trick you to think it’s different”