A metallic bioelement, atomic no. 28, atomic wt. 58.6934, closely resembling cobalt and often associated with it. Protects ribosome structure against heat denaturation. A deficiency of n. causes changes in the ultrastructure of the liver. It is a cofactor in a number of enzymes ( e.g., urease). [abbrev. fr. Ger. kupfer-n., name of copper-colored ore from which n. was first obtained; n., the Ger. word for a dwarfish imp]
- Raney n. See Raney N..
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nick·el 'nik-əl n a silver-white hard malleable ductile metallic element capable of a high polish and resistant to corrosion that is used chiefly in alloys and as a catalyst symbol Ni see ELEMENT (table)
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nick·el (Ni) (nikґəl) [L. niccolum] a silver-white metallic element; specific gravity, 8.9; atomic number, 28; atomic weight, 58.71. Long-term excessive exposure to metallic nickel, as in jewelry, can cause contact dermatitis (nickel dermatitis); excessive exposure to nickel fumes can cause nasal and lung cancers.Medical dictionary. 2011.