Droplet Microfluidic Device for Chemoenzymatic Sensing.

The rapid detection of pollutants in water can be performed with enzymatic probes, the catalytic light-emitting activity of which decreases in the presence of many types of pollutants. Herein, we present a microfluidic system for continuous chemoenzymatic biosensing that generates emulsion droplets containing two enzymes of the bacterial bioluminescent system (luciferase and NAD(P)H:FMN-oxidoreductase) with substrates required for the reaction. The developed chip generates "water-in-oil" emulsion droplets with a volume of 0.

An asymmetric flow-focusing droplet generator promotes rapid mixing of reagents.

Nowadays droplet microfluidics is widely used to perform high throughput assays and for the synthesis of micro- and nanoparticles. These applications usually require packaging several reagents into droplets and their mixing to start a biochemical reaction. For rapid mixing microfluidic devices usually require additional functional elements that make their designs more complex.

Naive geography: geoconceptology and topology of geomental maps.

The article presents the study of the geospace mental representations and their variability depending on the regional point of view. The research material comprises about 500 naive maps of Russia, created by informants of seven Russian regions: Moscow, St. Petersburg (capitals), Siberia (Barnaul, Biysk), Southern, Mid- and Northern Ural (Orenburg, Ufa, Perm) and Kaliningrad.

Bouncing off the Walls: The Influence of Gas-Kinetic and van der Waals Effects in Drop Impact.

A model is developed for liquid drop impact on a solid surface that captures the thin film gas flow beneath the drop, even when the film's thickness is below the mean free path in the gas so that gas kinetic effects (GKE) are important. Simulation results agree with experiments, with the impact speed threshold between bouncing and wetting reproduced to within 5%, while a model without GKE overpredicts this value by at least 50%. To isolate GKE, the pressure dependence of the threshold is mapped and provides experimentally verifiable predictions.