The structure of a polyketide synthase bimodule core.

Polyketide synthases (PKSs) are predominantly microbial biosynthetic enzymes. They assemble highly potent bioactive natural products from simple carboxylic acid precursors. The most versatile families of PKSs are organized as assembly lines of functional modules.

Depressive symptoms among teenagers in the emergency department: prevalence estimate and concordance with parental perceptions.

Purpose: This study aims to estimate the prevalence of depressive symptoms among adolescents seen in hospital emergency departments and to investigate the concordance between self-reported adolescent depression and parental perceptions of their adolescents' health status.

Method: A multicentre cross-sectional survey in three emergency departments receiving adolescents in Ile-de-France took place in 2010. All adolescents completed a questionnaire including the Adolescent Depression Rating Scale (ADRS) and a series of questions concerning somatisation and risk behaviours.