Urinary Concentrations of Diisoheptyl Phthalate Biomarkers in Convenience Samples of U.S. Adults in 2000 and 2018-2019.

We know little about the potential health risks from exposure to diisoheptyl phthalate (DiHpP), a plasticizer used in commercial applications. The production of DiHpP ended in the United States in 2010, but DiHpP may still be present in phthalate diester mixtures. To investigate human exposure to DiHpP, we used three oxidative metabolites of DiHpP: Monohydroxyheptyl phthalate (MHHpP), mono-oxoheptylphthalate (MOHpP), and monocarboxyhexyl phthalate (MCHxP) as exposure biomarkers.

Engineering Proton Transfer in Photosynthetic Oxygen Evolution: Chloride, Nitrate, and Trehalose Reorganize a Hydrogen-Bonding Network.

Photosystem II oxidizes water at a MnCaO cluster. Oxygen evolution is accompanied by proton release through a 35 Å hydrogen-bonding network to the lumen. The mechanism of this proton-transfer reaction is not known, but the reaction is dependent on chloride.