QUESTION I have a pregnant patient who regularly consumes sugar substitutes and she asked me if continuing their use would affect her pregnancy or child. What should I tell her, and are there certain options that are better for use during pregnancy? ANSWER Although more research is required to fully determine the effects of in utero exposure to sugar substitutes, the available data do not sug...

Stimulated by concerns of potential infective agents in donated blood, commercial enterprises have attempted to develop blood substitutes since the 1900s. After several years of development, a few of the many leads are showing promise. In this article, nanobiotechnological approaches that are now in phase III clinical trials are reviewed, followed by a discussion of how important basic knowledg...

The recent transplantation of an unusual allosteric effect from crocodile to human haemoglobin has implications for both molecular evolution and the engineering of artificial blood substitutes.

We distinguish two notions of substitutes for discrete inputs of a firm. Class substitutes are defined assuming that units of a given input have the same price while unitary substitutes treat each unit as a distinct input with its own price. Unitary substitutes is necessary and sufficient for such results as the robust existence of equilibrium, the robust inclusion of the Vickrey outcome in the...