The author was referring to the steam holiday gems. They are a new feature (released yesterday) in which a steam user can turn their extra junk cards/backgrounds/emotes into gems.. These gems can be used to buy more cards; or, during the upcoming holiday event only, to bid on games.
Acinar cells. 1  Acinar cells are the exocrine (exo=outward) cells of the pancreas that produce and transport enzymes that are passed into the duodenum where they assist in the digestion of food.
An acousto-optic modulator (AOM), also called a Bragg cell, uses the acousto-optic effect to diffract and shift the frequency of light using sound waves (usually at radio-frequency). They are used in lasers for Q-switching, telecommunications for signal modulation, and in spectroscopy for frequency control.