substances

But in this case, fitting into a given pore depends on many more characteristics than just the shape of the toddler's peg, allowing certain pores to select for some substances over others -- what chemists call the "selectivity" of "molecular encapsulation," or just selective encapsulation.

The interior of this ring -- in general -- forms the cavity or pore where only certain substances "fit."

He told local media he was given electric shocks, chained to a bed and injected with substances.

Conspiracy theories have grown up around contrails, with some people alleging they are in fact “chemtrails” that contain chemical or biological substances.

They also found it didn't produce mycotoxins, the potentially deadly substances associated with some fungi.