Metastatic cancer cells differ from their non-metastatic counterparts not only in terms of molecular composition and genetics, but also by the very strategy they employ for locomotion. Here, we analyzed large-scale statistics for cells migrating on linear microtracks to show that metastatic cancer cells follow a qualitatively different movement strategy than their non-invasive counterparts. The trajectories of metastatic cells display clusters of small steps that are interspersed with long “flights”. Such movements are characterized by heavy-tailed, truncated power law distributions of persistence times and are consistent with the Lévy walks that are also often employed by animal predators searching for scarce prey or food sources. In contrast, non-metastatic cancerous cells perform simple diffusive movements. These findings are supported by preliminary experiments with cancer cells migrating away from primary tumors in vivo. The use of chemical inhibitors targeting actin-binding proteins allows for “reprogramming” the Lévy walks into either diffusive or ballistic movements.

Placed at a water/air interface, particles of porphyrin-based MOFs (metal-organic frameworks) cut from large-area films display efficient, multiple-use autonomous motility powered by release of solvents incorporated in the MOF matrix and directionality dictated by their shapes. The particles can be refueled multiple times and can achieve speeds of ca. 200 mm·s with high kinetic energy per unit of chemical "fuel" expended (>50 μJ·g). Efficiency of motion depends on the nature of the fuel used as well as the microstructure and surface wettability of the MOF surface. When multiple movers are present at the interface, they organize into "open" structures that exhibit collective, time-periodic motions.

AlphaFold2 (AF2) is a promising tool for structural biology, but is it sufficiently accurate to predict the effect of missense mutations? We find that structural variation between closely related 1-3 mutations) protein pairs is correlated across experimental and AF2-predicted structures ~90,000 pairs. Analysis of ~10,000 predicted structures from three high-throughput studies linking sequence and phenotype (fluorescence, foldability, and catalysis) demonstrates that AF2 can predict the phenotypic effect of missense mutations.

This paper describes granular crystals held together by unusual, multipolar interactions and, under application of external bias, undergoing reversible structural transitions between closed and open forms. The system is comprised...