Noun [edit]. viola â(plural violas). ( 1 music) A stringed instrument of the violin family, somewhat larger than a violin, played under the chin, and having a deeper tone. ( 2 music) An organ stop having a similar tone. ( 3 music) A 10-string steel-string acoustic guitar, used in Brazilian folk music.oun [edit]. viola â(plural violas). ( 1 music) A stringed instrument of the violin family, somewhat larger than a violin, played under the chin, and having a deeper tone. ( 2 music) An organ stop having a similar tone. ( 3 music) A 10-string steel-string acoustic guitar, used in Brazilian folk music.
Dipalmitoylphosphatidylcholine (DPPtdCho) is a phospholipid (and a lecithin) consisting of two palmitic acids attached of a phosphatidylcholine head-group and is the major constituent of many pulmonary surfactants. It is zwitterionic by virtue of having a negative charge on the phosphate group and a positive charge on the quaternary ammonium group.
Phosphatidylcholine (PPC) and sodium deoxycholate (DC) are both approved by the U.S. Food and Drug Administration (FDA) for use as surfactants and drug carriers, among other applications, but neither is approved for subcutaneous injection. Lipodissolveâ¢ and Lipostabilâ¢ are not approved by the FDA.