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991.
Pro- and Antioxidants in the Field of Fats XVII: Fats and Fat-metabolism of Hibernating Animals I. The Seven Sleepers. (Glis glis L.) After a short review of the literature about hibernation, the analysis of the lipids of the seven sleepers (Glis glis L.) is given. The problem, whether the yellow lipochrome results from the autoxidation of polyenoic fatty acids because of the decrease in biological antioxidants, especially vitamin E, could not be completely explained. The brown tissue, the socalled “sleep gland” contains substances which are insoluble in fat solvents and probably formed by the reaction of polyenes with proteins or by the autoxidation of lipoproteins which contain them.  相似文献   
992.
The empirical equation, 1/ti = AeEi/RT, which expresses the exponential dependence of the reciprocal of crystallization induction time, ti, has been analyzed and shown to be equivalent to the nucleation rate equations derived earlier in Part III (1). Consequently we have used the ti measurements obtained earlier by Krueger and Yeh to calculate not only the nucleation rate enhancements but also the melting point elevations, the relative crystal thickness changes and molecular coil extension ratios of shear-crystallization polyethylene. It is shown that polyethylene when crystallized between 129 and 131°C at shear rates between 1.56 and 9.70 sec?1 can have melting point increases of 4.2 to 7.2°C and crystal thickness decreases of 20 to 25 percent, when compared to those crystallized at 130°C in the quiescent state. The predicted “coil” extension in the melt just prior to shear-induced crystallization ranges between 21 and 36 percent. The results of these analyses as well as those on nucleation rates of polyethylene oxide are discussed in detail.  相似文献   
993.
994.
Journal of the American Oil Chemists' Society - Scanning electron microscopy was used to study the crystal structure of hydrogenated Canola oil. Fixation of the samples was carried out at 10 C...  相似文献   
995.
996.
The fatty acids of subcutaneous triacylglycerols (containing ca. 11% of branched chain components) from lambs fed on barley-rich diets were fractionated by treatment with mercuric acetate and by urea adduct formation to yield concentrates rich in the branched chain components, all of which were saturated. The concentrates were subjected to analysis by high resolution gas liquid chromatography in conjunction with mass spectrometry. The branched chain fatty acids consisted of a complex mixture of mono-, di-, and trimethyl substituted components. The greater part of the mixture comprised monomethyl substituted acids of chain length 10–17 carbon atoms. Within each of these molecular species, a number of positional isomers was identified, notably in respect of methyltetradecanoic acid (methyl substituent on carbon 2, 4, 6, 8, 10, and 12) and methylhexadecanoic acid (methyl substituent on carbon 2, 4, 6, 8, 12, and 14). Homologous series also could be recognized of one of which all eight members from 4-methyldecanoic acid to 4-methylheptadecanoic acid were identified; together they accounted for ca. 39% of the branched chain fatty acids which were sampled for mass spectrometry. The dibranched acids identified consisted of five members of a homologous series, ranging in chain length from 11–15 carbon atoms and with substituent methyl groups at positions 4 and 8. Though the identity of only one tribranched acid (2,6,10-trimethyltetradecanoic acid) was established, others also apparently were present in the mixture. The probable involvement of methylmalonate in the biosynthesis of these branched chain acids is discussed briefly, with particular reference to the availability of vitamin B12 in relation to the activity of methylmalonyl coenzyme A mutase.  相似文献   
997.
998.
Even chain sodium alkanesulfonates from the Strecker reaction, odd chain sodium alkanesulfonates from the alkaline decarboxylation of α-sulfo acids, and sodium 1-hydroxy-2-alkanesulfonates from the reduction of esters of α-sulfo acids were compared with respect to Krafft point, critical micelle concentration, detergency and foam height. Sodium alkanesulfonates and crude fusion products from the α-sulfo acids (mixtures of alkanesulfonates of one less carbon atom with a lesser amount of a soap of two less carbon atoms) are more soluble and have better detergent and foaming properties. Sodium 1-hydroxy-2-alkanesulfonates resemble monosodium salts of α-sulfo acids. Alkanesulfonic acids and 1-hydroxy-2-alkane-sulfonic acids obtained from the sodium salts by ion exchange have lower Krafft points and are more readily soluble. The critical micelle concentrations of 1-hydroxy-2-alkanesulfonic acids and α-sulfo acids are nearly the same and about equal to those of alkanesulfonic acids of one less carbon atom. Presented at the AOCS meeting in Toronto, Canada, 1962. A laboratory of the E. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.  相似文献   
999.
Composition of the Seed Oil of Clustered Elder (Sambucus racemosa L.) The seeds of clustered elder (Sambucus racemosa L.) contain 28% of an oil. Its separation to groups of components was carried out by adsorption chromatography. Single groups of substances were further analysed by TLC and GLC in combination with physico-chemical methods (IR and MS). Thus the following substances were found and identified: n-alkanes (C17–C33), 2-methyl- and 3-methylalkanes, squalene, a mixture of esters, triglycerides, β-sitosterol, campesterol and a mixture of diglycerides. The conditions for the separation of esters by silica gel column chromatography were also found. The mixture of esters was thus separated into a group of aliphatic wax esters (C34–C44) and four groups of esters of steroidal alcohols (mainly β-sitosterol and campesterol) with aliphatic unsaturated acids (predominantly C18:1, C18:2 and C18:3). In the triglycerides representing the main fraction of the oil (93%), the acids C16:0, C18:1, C18:2 and C18:3 are present. The same acids were also found in diglycerides.  相似文献   
1000.
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