The Fermionic Massless Modular Hamiltonian.

We provide an explicit expression for the modular hamiltonian of the von Neumann algebras associated to the unit double cone for the (fermionic) quantum field theories of the 2-component Weyl (helicity 1/2) field, and of the 4-component massless Dirac and Majorana fields. To this end, we represent the one particle spaces of these theories in terms of solutions of the corresponding wave equations, and obtain the action of the modular group on them. As an application, we compute the relative entropy between the vacuum of the massless Majorana field and one particle states associated to waves with Cauchy data localized in the spatial unit ball.

Correction: Substituent interference on supramolecular assembly in urea gelators: synthesis, structure prediction and NMR.

Correction for 'Substituent interference on supramolecular assembly in urea gelators: synthesis, structure prediction and NMR' by Francesca Piana et al., Soft Matter, 2016, 12, 4034-4043.

Substituent interference on supramolecular assembly in urea gelators: synthesis, structure prediction and NMR.

Eighteen N-aryl-N'-alkyl urea gelators were synthesised in order to understand the effect of head substituents on gelation performance. Minimum gelation concentration values obtained from gel formation studies were used to rank the compounds and revealed the remarkable performance of 4-methoxyphenyl urea gelator 15 in comparison to 4-nitrophenyl analogue 14, which could not be simply ascribed to substituent effects on the hydrogen bonding capabilities of the urea protons. Crystal structure prediction calculations indicated alternative low energy hydrogen bonding arrangements between the nitro group and urea protons in gelator 14, which were supported experimentally by NMR spectroscopy.

Detection of nerve agent via perturbation of supramolecular gel formation.

The formation of tren-based tris-urea supramolecular gels in organic solvents is perturbed by the presence of the nerve agent soman providing a new method of sensing the presence of organophosphorus warfare agents.