Tuesday, July 31, 2012

word of the day: smectic

The word of the day is smectic:

Etymology:  < Latin smēcticus (Pliny), < Greek σμηκτικός , < σμήχειν to wipe, cleanse 
1. Cleansing, abstersive, detergent. rare.
2. Physical Chem. Applied to (the state of) a mesophase (a liquid crystal) in which the molecules all have the same orientation and are arranged in well-defined planes.  (OED)

"From the recent work of de Haas and co-workers, it appeared that the mode of aggregation of lecithins plays an essential role in their interaction with porcine pancreatic lipase A.  This enzyme catalyses the hydrolysis of the 2 fatty acid ester bonds.  It was found to be very weakly active on dispersions of natural or synthetic lecithins, when aggregated in the form of smectic liquid crystals."

 - Tausk et al., "Physical chemical studies of short-chain lecithin homologues.  I.  Influence of the chain length of the fatty acid ester and of electrolytes on the critical micelle concentration", Biophysical Chemistry 1:175 (1973)

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