Lipid-lowering phenomenon

Thus we discovered a new phenomenon of phase transition for alamethicin in a membrane. The phase diagram (Figure 6) is characterized by a phase boundary that ends at a critical lipid.-peptide molar ratio L P at 100% RH. If the lipid-peptide ratio is greater than L P (that is, at a low peptide concentration), alamethicin is always on the membrane surface in equilibrium. For L P smaller than L P, alamethicin is always inserted in the membrane in equilibrium at 100% RH, but if RH is below the phase boundary, alamethicin is again on the membrane surface. Starting from the critical L P, the phase boundary decreases to lower RH for lower L P. 

In hepatocytes cultured in the presence of oleic acid, incorporation of pH]-water into secreted lipids and TG was lower than incorporation into synthesized lipids with the 3-thia fatty acids. ° A similar phenomenon was observed with pH]-glycerol as the radioactive precursor. This suggests that some of the hypotriglyceridemic effects of 3-thia fatty acids may arise from a reduction in biosynthesis and/or secretion of TG. 

Third, the mass resolution of the ion peaks in either precursor-ion scans or the SRM experiments is always lower than those observed in fiill mass spectra, product-ion spectra, or neutral-loss scans. This phenomenon is probably due to a minor time-lag resulting from a different free path experienced by the interrogated ions in the collision cell [22], Reduction of the collision gas pressure, which can be compensated with an increase in collision energy to achieve an optimized fragmentation, is advisable if peak-broadening becomes an issue in either precursor-ion scans or SRM analyses of lipids. 

The crumb structure also changes, although at a lower rate. The crumb becomes firm, its elasticity and juiciness are lost, and it crumbles more easily. The so-called staling defect of the crumb is basically a starch retrogradation phenomenon (cf. 4.4.4.14.2) which proceeds at different rates with amylose and amylopectin. On cooling bread, the high-molecular amylose very rapidly forms a three-dimensional network and the crystalline states of order of amylose/lipid complexes increase. These processes stabilize the crumb. 

The absolute values of the interfacial tensions varied between different amphi-philes and solvents (Table 1). AOT, which is well known in the literature for the formation of microemulsions, showed the lowest surface tension at the interface of both solvents. The other nonionic snrfactants mentioned here. Span 80 and Brij 72 showed shghtly higher valnes. This was also observed for Lecithine, but this lipid precipitated partly during the spinning-drop measurements. Due to this phenomenon, it was not possible to measure accurate data for this emulsifying compound. The interfacial tension had also some influence on the mean size of the emulsion droplets and on the stability of the vesicles (Table 3). In addition to the stationary values of the surface tension, dynamic processes as the surfactant diffusion represented another important factor for the process of stimulated vesicle formation. If an aqueous droplet passed across the fluid interface it carried-over a thin layer of emulsifiers and thereby lowered the local surfactant concentration in the vicinity of the oil-water interface. In the short time span, before the next water droplet approached the interface, the surfactant films should entirely reform and this only occurred, if the surfactant diffusion was fast enough. 

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