This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American Urea is a small molecule formed as proteins ...

Asymptomatic Subjects. Sixty-five healthy, asymptomatic volunteers aged 54.2 ± 2.0 years (mean ± SEM; range 20 86 years) were involved in the present study. All subjects were initially screened for H.