Adsorption at the air-water interface and aggregation in dilute solutions of sodium ricinoleate (sodium 12-hydroxy-cis-9-octadecenoate) (NaR) have been investigated. The mid-chain polarity due to the presence of a double bond and hydroxy group have a profound influence on the dilute solution properties of NaR. The area per molecule obtained at the air-water interface (1.06 nm2) suggests that the molecule takes up a wicket shape with both carboxyl and hydroxyl groups residing at the interface. Studies on the micellar state appear to indicate the formation of premicellar aggregates. NaR fonns small micelles with a low aggregation number (-34). The micelles are probably ellipsoidal and have a high degree of counterion dissociation (77%). These results suggest that NaR behaves like a short chain surfactant and adopts a bent-wicket-like conformation in the micelles. 'H and 13C NMR of NaR at concentrations below and above the critical micelle concentration (cmc) support the wicketlike conformation of NaR in the micelles.
Background:Vertigo is one of the most distressing symptom seen in patients encountered in clinical practice by otolaryngologist and neurologist. It results from dysfunction of vestibular system, among which most common is BBPV(benign paroxysmal positional vertigo). BPPV present with short episodes of vertigo lasting for few seconds, usually precipitated by change in head position. In BPPV, otoconia from utricles are thought to collect in semicircular canal making them abnormally gravity sensitive. BPPV is clinical diagnosis on the basis of typical history and Dix Hallpike testing. Dr. T Brandt and Daroff introduced Brandt daroff home exercises based on cupulolithiasis theory. In 1980, John M Epley introduced canalolith repositioning procedure of Epley in the treatment of BPPV. Because of lack of consensus regarding the optimal treatment maneuver, in our study we have compared the effectiveness of Brandt Daroff and Epleys maneuver.
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