This allows the stratum corneum to be exfoliated, exposing live skin cells. The microdermabrasion vacuum removes the crystals and exfoliated skin cells. Mechanically exfoliated monolayers of are transparent photovoltaic materials with LED properties. Intermediate and superficial cells are constantly exfoliated from the epithelium. The diagnosis of oropharyngeal cancer occurs by biopsy of exfoliated cells or tissues. Hoses and masks accumulate exfoliated skin, particulate matter, and can even develop mold. NbSe monolayers can also be exfoliated from the bulk or deposited by molecular beam epitaxy. The superficial cells are exfoliated continuously. Hexagonal boron nitride can be exfoliated to mono or few atomic layer sheets. Therefore, TMDCs can be easily exfoliated into atomically thin layers through various methods. This is then exfoliated to isolate borocarbonitride layers. In shrubs, older bark is quickly exfoliated and thick rhytidome accumulates. Exfoliated graphite nano-platelets (xGnP) are new types of nanoparticles made from graphite.