Fluorescent Discrimination between Traces of Chemical Warfare Agents and Their Mimics

An array of fluorogenic probes is able to discriminate between nerve agents, sarin, soman, tabun, VX and their mimics, in water or organic solvent, by qualitative fluorescence patterns and quantitative multivariate analysis, thus making the system suitable for the inthe- field detection of traces of chemical warfare agents as well as to differentiate between the real nerve agents and other related compounds.Ministerio de Economía y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411) and the Swedish Ministry of Defence (no. A403913

Does the diurnal cycle of cortisol explain the relationship between physical performance and cognitive function in older adults?

Background Regular physical activity is a promising strategy to treat and prevent cognitive decline. The mechanisms that mediate these benefits are not fully clear but physical activity is thought to attenuate the harmful effects of chronic psychological stress and hypercortisolism on cognition. However, the circadian pattern of cortisol secretion is complex and it is not known which aspects are most closely associated with increased cognitive function and better physical performance. This is the first study to simultaneously measure cognitive function, the diurnal cycle of salivary cortisol and physical performance in older adults, without cognitive impairment (n = 30) and with amnestic Mild Cognitive Impairment (aMCI) (n = 30). Results Regression analysis showed that better cognitive function was associated with better physical performance. A greater variance in cortisol levels across the day from morning to evening was associated with better cognitive function and physical performance. Conclusions The results support the idea that a more dynamic cortisol secretion pattern is associated with better cognitive function and physical performance even in the presence of cognitive impairment, but our results could not confirm a mediating role in this relationship

Controlling binding dynamics of corrin-based chemosensors for cyanide

This paper describes a strategy to control the binding dynamics between cyanide and aquacyanocorrinoids on the molecular level. Aquacyanocorrinoids represent an important class of chemosensors and convert upon cyanide coordination to the corresponding dicyano derivatives. Structure–reactivity relationships were investigated for the first time by synthesizing and studying three diastereomerically pure aquacyanocorrinoids differing either in the configuration of the axially bound ligands or in the nature of remote side chains located at the periphery of the corrin macrocycle. Substitution of cobalt-coordinated water with cyanide was investigated using stopped-flow measurements between 5 and 30 °C, and second order rate constants and activation parameters were determined. In particular, it is demonstrated that the binding kinetics depend not only on (i) the configuration at the central metal center but also on (ii) the remote structural modifications of the macrocycle