Spontaneously rotating clusters of active droplets.

We report on the emergence of spontaneously rotating clusters in active emulsions. Ensembles of self-propelling droplets sediment and then self-organise into planar, hexagonally ordered clusters which hover over the container bottom while spinning around the plane normal. This effect exists for symmetric and asymmetric arrangements of isotropic droplets and is therefore not caused by torques due to geometric asymmetries.

Thermal Population Fluctuations in Two-Dimensional Infrared Spectroscopy Captured with Semiclassical Mechanics.

Time-resolved two-dimensional (2D) infrared spectra of the asymmetric stretch mode of solvated CO show distinct features corresponding to ground- and excited-state thermal populations of the bend modes. The time-dependence of these peaks arises in part from solvent-driven thermal fluctuations in populations of the lower-frequency bend modes through their coupling to the higher-frequency asymmetric stretch. This observation illustrates the capacity of multidimensional vibrational spectroscopy to reveal details of the interactions among vibrational modes in condensed phases.

pH changes the aggregation propensity of amyloid-β without altering the monomer conformation.

Decoupling conformational changes from aggregation will help us understand amyloids better. Here we attach Alzheimer's amyloid-β(1-40) monomers to silver nanoparticles, preventing their aggregation, and study their conformation under aggregation-favoring conditions using SERS. Surprisingly, the α-helical character of the peptide remains unchanged between pH 10.

On/off luminescence vapochromic selective sensing of benzene and its methylated derivatives by a trinuclear silver(I) pyrazolate sensor.

{[3,5-(CF(3))(2)Pz]Ag}(3) (1) films exhibit selective/reversible sensing of small-organic-molecule (SAM) vapors, which readily switch-on bright-green (benzene or toluene) or bright-blue (mesitylene) luminescence that switches-off upon vapor removal. Vapors of electron-deficient SAMs or non-aromatic solvents did not attain luminescence switching and were not adsorbed.