Correction: Spatially heterogeneous dynamics of cells in a growing tumor spheroid: comparison between theory and experiments

Correction for ‘Spatially heterogeneous dynamics of cells in a growing tumor spheroid: comparison between theory and experiments’ by Sumit Sinha et al., Soft Matter, 2020, 16, 5294–5304, DOI: 10.1039/C9SM02277E.

Spatially heterogeneous dynamics of cells in a growing tumor spheroid: comparison between theory and experiments

Spatially heterogenous dynamics inside a growing tumor spheroid.

Structure and Correlation Between the Fraction of Structural Units and Bond Angle Distribution in Liquid B2 O3 Under Compression

Structure of network-forming liquid B2 O3 is investigated by Molecular dynamics simulation (MDS) at 2000K and in the 0-40 GPa pressure range (corresponding to the 1.71-3.04 g/cm3 density range). Results indicate that network structure of liquid B2 O3 comprises of basic structural units BO3 and BO4 . The topology and size of BO3 and BO4 units at different densities are identical. The O-B-O and B-O-B partial bond angle distributions (BADs) can be determined through the fraction of BO3 and BO4 units. Furthermore, the total BADs are directly related to the partial BADs and the fraction of structural units. It means the fraction of units BOX (X = 3,4) and units OBy (y = 2,3) can be determined from the experimental BADs. The spatial distribution of BO3 and BO4 units is not uniform but forming clusters of BO3 and BO4 . This leads to the polyamorphism in liquid B2 O3 . It also shows that the dynamical heterogeneity in liquid B2 O3 due to the lifetimes of BO3 and BO4 units are very different. The structural heterogeneity is origin of spatially heterogeneous dynamics in liquids B2 O3 .

Viscosity of deeply supercooled water and its coupling to molecular diffusion

The viscosity of a liquid measures its resistance to flow, with consequences for hydraulic machinery, locomotion of microorganisms, and flow of blood in vessels and sap in trees. Viscosity increases dramatically upon cooling, until dynamical arrest when a glassy state is reached. Water is a notoriously poor glassformer, and the supercooled liquid crystallizes easily, making the measurement of its viscosity a challenging task. Here we report viscosity of water supercooled close to the limit of homogeneous crystallization. Our values contradict earlier data. A single power law reproduces the 50-fold variation of viscosity up to the boiling point. Our results allow us to test the Stokes–Einstein and Stokes–Einstein–Debye relations that link viscosity, a macroscopic property, to the molecular translational and rotational diffusion, respectively. In molecular glassformers or liquid metals, the violation of the Stokes–Einstein relation signals the onset of spatially heterogeneous dynamics and collective motions. Although the viscosity of water strongly decouples from translational motion, a scaling with rotational motion remains, similar to canonical glassformers.