No abstract

No abstract

A pseudophase diagram for ternary compositions of n-hexane, water and 2-propanol has been published previously. Some of the compositions exhibited the physical characteristics of a water/oil (w/o) microemulsion even though a detergent was not present. We have now determined the effect of ionic materials on the system by replacing water with NaCI solutions'. Addition of NaCI caused significant changes in the location of region boundaries. The microemulsion was stabilized while a region of small H-bonded aggregates appeared to be destabilized by the added NaCI. An investigation of these systems by NMR, with or without added NaCI, showed that "bulk" water was present in the detergentless microemulsion. In addition, NMR was found to be a useful tool for locating region boundaries and for elucidating the nature of compositions assigned to these regions.

No abstract

Varieties of pyruvate carboxylase [pyruvate:CO2 ligase (ADP-forming), EC 6.4. Structural studies with transcarboxylase from Propionibacterium shermanli (9) and acetyl-CoA carboxylase from Escherichla coli (3, 10) have revealed a close correlation be-* Present address: