There may be regional specialisation in structure and function across the placental surface. In Riyadh, Saudi Arabia, the length and the breadth of the placental surface at birth were highly correlated, but the breadth was more closely associated with the size of the baby. To replicate this we studied 321 pregnant Saudi women in the town of Baish. We measured the size of the newborn babies and their placentas.

Toxicity of nanoparticles depends on many factors including size, shape, chemical composition, surface area and surface charge. Silver nanoparticles (AgNPs) are likely to enter the aquatic ecosystems because of their multiple applications and pose a health concern for humans and aquatic species. Therefore, we used a freshwater snail Lymnaea luteola L (L. luteola) to investigate the acute toxicity and genotoxicity of AgNPs in a static-renewal system for 96 h. AgNPs caused molluscicidal activity in L. luteola, with 96 h median lethal concentrations (LC50) (48.10 mu g L-1).