1982
Brominated surfactants are prepd. by the complete bromination of the double bonds in the hydrophobic chains of the oleic acid [112-80-1], linoleic acid [60-33-3], Span 80 [1338-43-8], Span 85 [26266-58-0], Tween 80 [9005-65-6], and Tween 85 [9005-70-3]. The addn. of Br increases the sp. gr. of the surfactant mol. to values above that of water, allowing the formation of oil-in-water emulsions with denser droplets, i.e., the surfactants are emulsifiers and weighting agents. The surfactant properties of the brominated surfactants are discussed. [on SciFinder(R)]
The less thermodynamically stable modification of tristearin [555-43-1], termed $\alpha$, is preserved when 1-10% of sorbitan monostearate [1338-41-6] emulsifier was added before allowing the molten fat to cool and crystallize. Several other emulsifiers were tested, and it was found that the combination of bulkiness of the hydrophilic groups and the appropriate length of the hydrophobic chains of a given emulsifier is necessary to preserve the $\alpha$-modification. Liq. emulsifiers and those having a pronounced hydrophilic character are not efficient as modifiers. The emulsifier was incorporated into the tristearin during crystn. from solvent without an immediate effect, but it affects subsequent behavior upon melting and resolidification. [on SciFinder(R)]
Stearic acid can exit in 3 main crystal structure modifications. The crystal structure is detd. by solute-solvent interactions. When changes occur in the growth conditions, for instance in flow regime or by increased cooling rate, the crystal modification is affected. Addn. of small amts. of surfactants will force the stearic acid to crystallize in only one modification regardless of the crystn. and the nature of the solvent. [on SciFinder(R)]
It has been found that calcium oxalate stone formers have low UGOT and UGPT activity compared to healthy individuals. The urine of 23 stone formers and 19 controls has been tested for combined UGOT and UGPT activity. The effect of L-aspartic acid, alanine and L-glutamic acid on calcium oxalate precipitation has been tested. Only L-glutamic acid exerted a significant retardation effect at physiological concentrations. As GPT and GOT convert alanine and aspartic acid respectively into glutamic acid, a possible mechanism of retardation of kidney stone formation involving enzyme steps via glutamic acid creation in situ is suggested.[on SciFinder (R)]
S SARIG, Garti, N, AZOURY, R, WAX, Y, and PERLBERG, S. 1982.
“A Method For Discrimination Between Calcium Oxalate Kidney Stone Formers And Normals”. The Journal Of Urology, 128, 3, Pp. 645–649.
Calcium ion concentration versus time was measured in solutions containing admixture of 10 per cent tested urine of normals and stone-formers, during induced calcium oxalate precipitation. A Discriminating Index was formulated by statistical analysis of the data. It was found that stone-formers and normals differ significantly with respect to the measurements and the Discriminating Indices. An equation to evaluate the odds of stone-forming based on results of an individual test has been derived. The Discrimination Index may be recommended as a diagnostic tool.[on SciFinder (R)]
Fatty acid esters of glycerol or tetraglycerol are prepd. by the transesterification of Me esters of fatty acids (esp. Me stearate [112-61-8]) with glycerol or tetraglycerol at 95-150° in the presence of an alk. catalyst and an anionic or nonionic emulsifier. These esters are not highly substituted. Emulsion formation and the catalyst are required for high transesterification yields. The effects of temp., type and concn. of emulsifier, and reactant ratio on the transesterification were examd. [on SciFinder(R)]
Product compn. of polyglycerol esters, prepd. from a direct alk. polymn. of glycerol followed by esterification with stearic or oleic acids, was studied. The internal product compn., as analyzed by high performance liq. chromatog. (HPLC), shows clearly that in contradiction to what has been published recently, the fatty acid radicals are not distributed at random among all available hydroxyl groups, and thus, any theor. calcn. on the product compn. could not be correct. The product compn. of the crude material indicates clearly that the internal positions (secondary hydroxyls) of the glycerol polymer are esterified with greater difficulty than the primary hydroxyl groups. [on SciFinder(R)]
It has been found that calcium oxalate stone formers have low UGOT activity compared to healthy individuals (controls). Urine from stone formers with no GOT activity and no effect on calcium oxalate precipitation was incubated with GOT for various periods. Subsequently calcium oxalate precipitation was decreased and found to be considerably retarded i.e., the pathological urine after the incubation acted in a way similar to that of normal urine. The yield of Glutamic-Oxalacetic Transaminase (GOT) activity is glutamic acid. It was shown that glutamic acid has a significant retardation effect on the precipitation of calcium oxalate stone formation. Therefore it may be suggested that GOT activity involved in glutamic acid creation in situ, has a role in kidney stone formation.[on SciFinder (R)]
Z. Goldman, Garti, Nissim , Sasson, Yoel , Ginzburg, Ben Zion , BLOCH, MR , Ginzburg, M.E. , and Porath, Asher . 1982.
“Conversion Of Halophilic Algae Into Extractable Oils.”. United States of America 4341038. doi:10.1016/0016-2361(80)90163-5.
A nonconventional method for the evaluation of emulsion stability was developed. The method was valid for viscous emulsions. The technique is based on elec. cond. measurements during nondestructive short-cooling-heating cycles carried out on cosmetic viscous emulsions. Cond. curves were obtained on a recorder, where the second heating cycles were lower and almost parallel to the first heating curves. The bigger the cond. differences between the two heating curves, the lower was the emulsion stability. A relative Stability Index $Δ$/h, indicating relative change in cond. between 2 cycles was elaborated. This index was useful for detg. optimal required hydrophile-lipophile balance values for required emulsions, optimal amt. of oily phase and emulsifier concn. [on SciFinder(R)]
The oxidn. of oleic acid and the cleavage of the carbon-carbon bond was achieved using potassium permanganate added to oil in water emulsion. The best emulsifier for the oxidn. and cleavage of the double bond was polyoxyethylene lauryl ether (HLB 16.9) which formed the best emulsion with the smaller droplets. The oxidn. is controlled by parameters affecting emulsion stability. Increasing the concns. of emulsifier or oxidizing agent improves the oleic acid conversion and azelaic acid formation. Poor stirring, low HLB's, high oil phase content and poor emulsion prepn. decrease the yields. [on SciFinder(R)]
DTA anal. was used to confirm evidence from x-ray diffraction studies for the existence of 1:1 mixed sitosterol-cholesterol crystals. The curve of m.p. against compn. has an inflection point at about 1:1 ratio. The DTA peaks for 1:1 mech. mixts. and for 1:1 mixed crystals are different with respect to symmetry and width. The curve of the heat of enthalpy against the compn. of crystals also changes indicating a change in entropy. This can be attributed to the difference between melting mixed crystals (high order) and solid soln. (low order). The soly. curve in the sitosterol-cholesterol-alc. system has also a region of inflection confirming the previous conclusion. [on SciFinder(R)]