Recent physical studies on the lipids of biological membranes have emphasized the potential instability of the lamellar phase of mixtures of lipids containing unsaturated species of phosphatidylethanolamine, plasmenylethanolamine, or monoglycosyldiacylglycerols, all of which are important constituents of the membranes of different groups of prokaryotes. The polar lipid compositions of bacteria ...

[1] Prediction of water flow and transport processes in soils susceptible to structural alteration such as compaction of tilled agricultural lands or newly constructed landfills rely on accurate description of changes in soil unsaturated hydraulic conductivity. Recent studies have documented the critical impact of aggregate contact characteristics on water flow rates and pathways in unsaturated...

Abnormal HDL metabolism among patients with diabetes and insulin resistance may contribute to their increased risk of atherosclerosis. ABCA1 mediates the transport of cholesterol and phospholipids from cells to HDL apolipoproteins and thus modulates HDL levels and atherogenesis. Unsaturated fatty acids, which are increased in diabetes, impair the ABCA1 pathway in cultured cells by destabilizing...

In this study, the interaction pattern and energies of a series of hydrocarbon dimers have been investigated by using a highly reliable quantum chemical method (M06-2X/cc-pVTZ). Saturated and unsaturated hydrocarbons in both cyclic and acyclic forms have been modelled to study their interaction. These dimers are found to involve different types of noncovalent interactions such as π-π (dimer of ...

Cholera toxin (CT) is an archetypal bacterial toxin that binds with a high affinity to the receptor ganglioside GM1 on the intestinal epithelial surface and that causes the severe watery diarrhea characteristic of the disease cholera. Blockage of the interaction of CT with the GM1 receptor is an attractive approach for therapeutic intervention. We report here that crude bile prevents the intera...

Anew computationally efficient directmethod is applied to estimating unsaturated hydraulic properties during steady-state infiltration and evaporation at soil surface. For different soil types with homogeneous and layered heterogeneity, soil hydraulic parameters and unsaturated conductivities are estimated. Unlike the traditional indirect inversion method, the direct method does not require for...

1. The effects of unsaturated fatty acids on drug-metabolizing enzymes in vitro were measured by using rat and rabbit hepatic 9000g supernatant fractions. 2. Unsaturated fatty acids inhibited the hepatic microsomal metabolism of ;type I' drugs with inhibition increasing with unsaturation: arachidonic acid>linolenic acid>linoleic acid>oleic acid. Inhibition was independent of lipid peroxidation....

The influence of various fatty acids of 14-18 carbon chain lengths on the binding of calcium to human serum albumin was studied. The cis-unsaturated fatty acids (myristoleic, palmitoleic, oleic, and linoleic) caused a much larger increase in the affinity and maximum binding of calcium for albumin than did saturated fatty acids (myristic, palmitic, and stearic). For the unsaturated fatty acids, ...

A semianalytical solution is presented for transient streaming potentials associated with flow to a pumping well in an unconfined aquifer, taking into account the effect of flow in the unsaturated zone above the water table. Flow in the unsaturated zone is modeled with a linearized form of Richards’ equation using an exponential model for soil moisture retention and unsaturated hydraulic conduc...

Cultures of a yeast mutant, deficient in the synthesis of unsaturated fatty acids, were supplemented with either stearolic acid or with any one of three octadecanoic acids having a cis double bond 6, 9, or 11 carbons away from the acyl group. The resulting cells, with lipid alkyl chains well defined with respect to the position and nature of unsaturated sites, were then studied with spin-labele...