Poly-phosphocholinated Liposomes Form Stable Superlubrication Vectors.

We have prepared phosphatidylcholine (PC) vesicles (liposomes) incorporating a novel lipid/poly-phosphocholine conjugate. This both stabilizes the liposomes against aggregation (for example, during storage or when being delivered) and allows them to act as very efficient lubricating elements readily attaining superlubric performance (defined as coefficient of friction µ < 10-2) via hydration lubrication at physiological salt concentrations and pressures. In contrast, vesicles sterically protected by poly(ethylene glycol) chains (PEGylation), which is the general method of choice, while being equally stable to aggregation are much poorer lubricants under these conditions, which is attributed to the relatively poor hydration of the PEG. Our approach enables the use of PC liposomes as stable superlubrication vectors in potential biomedical applications.

The seasoned executive's decision-making style.

Leaders make decisions every day of their lives, but how they do it changes dramatically over the course of their careers. At lower levels, the job is to get widgets out the door; action is at a premium. At higher levels, the job involves decisions about which widgets to offer and how to develop them. To climb the corporate ladder and be effective in new roles, managers need to change the way they use information and evaluate options. Based on a study of the decision-making profiles of more than 120,000 executives, the authors found that people make decisions very differently in public than they do in private and that the decision styles of successful managers evolve in highly predictable patterns. The most successful managers and executives become increasingly open and interactive in their leadership (or public) styles, and more analytic in their thinking (or private) styles, as they progress in their careers. The research shows that decision-making profiles do a complete flip over the course of a career; that is, the decision profile of a successful CEO is the opposite of a successful first-line supervisor's. When does the major change in focus occur? Somewhere between the manager level and the director level, executives find that formerly effective decision styles no longer work so well. At this point, decision styles fall into a "convergence zone", where managers use all styles more or less equally. From then on, the executives continue to evolve their styles. The most successful managers come to the convergence zone quickly and continue to adjust their styles as their careers progress. Low performers seem to stagnate once they hit the convergence zone; their styles do not evolve in new directions. Clearly, relying on past successes and habits is no guarantee of success-indeed, it may be the road to failure.