Modifying membrane potential synchronously controls the somite's formation periodicity and growth.

Coordination between periodicity of somite formation and somite growth is crucial for regular body pattern formation during somitogenesis. Yet, the specific mechanism that links the two processes remains unclear. Using chick embryos, we demonstrate that both temporal and spatial features can be simultaneously controlled by membrane potential (V) of somite-forming cells.

Dependence of cell's membrane potential on extracellular voltage observed in Chara globularis.

The membrane potential (V) of a cell results from the selective movement of ions across the cell membrane. Recent studies have revealed the presence of a gradient of voltage within a few nanometers adjacent to erythrocytes. Very notably this voltage is modified in response to changes in cell's membrane potential thus effectively extending the potential beyond the membrane and into the solution.

Voltage and concentration gradients across membraneless interface generated next to hydrogels: relation to glycocalyx.

Next to many hydrophilic surfaces, including those of biological cells and tissues, a layer of water that effectively excludes solutes and particles can be generated. This interfacial water is the subject of research aiming for practical applications such as removal of salts, pathogens or manipulation of biomolecules. However, the exact mechanism of its creation is still elusive because its persistence and extension contradict hydrogen-bond dynamics and electric double layer predictions.

Cells in New Light: Ion Concentration, Voltage, and Pressure Gradients across a Hydrogel Membrane.

The ionic compositions of the intra- and extracellular environments are distinct from one another, with K being the main cation in the cytosol and Na being the most abundant cation outside of the cell. Specific ions can permeate into and out of the cell at different rates, bringing about uneven distribution of charges and development of negative electric potential inside the cell. Each healthy cell must maintain a specific ion concentration gradient and voltage.

Propolis-induced exclusion of colloids: Possible new mechanism of biological action.

Propolis is a natural product originating from life activity of honeybees. It exhibits wide range of biological properties applicable in medicine, the food industry, and cosmetics. Chemically, propolis is a complex and variable mixture with more than 300 identified biologically active components.

Moving Water Droplets: The Role of Atmospheric CO and Incident Radiant Energy in Charge Separation at the Air-Water Interface.

One of the characteristics of aqueous interfaces is their negative charge, whose origin is still a subject of scientific debate. In this work, we provide spectroscopic evidence that bicarbonate anions, from dissolution of atmospheric CO, can be a source of negative charge at the air-water and/or solid-water interface. Also, interfacial charge separation, with a negatively charged droplet rim and positive charges gathering more toward the interior, makes water droplets receptive systems.

Beyond esterase-like activity of serum albumin. Histidine-(nitro)phenol radical formation in conversion cascade of p-nitrophenyl acetate and the role of infrared light.

Serum albumin, recognized mainly for its capacity to act as a carrier protein for many compounds, can also actively transform some organic molecules. As a starting point in this study, we consider esterase-like activity of bovine serum albumin (BSA) toward p-nitrophenyl acetate (p-NPA). Our results reveal that the reaction goes beyond ester hydrolysis step.

Spontaneous emulsification in ionic liquid/water systems and its use for templating of solids.

We report on the spontaneous formation of nano-sized ionic liquid/water (IL/W) emulsions in a simple system solely composed of an IL and aqueous solution of an inorganic salt. The IL ions play a dual role, that of both a surfactant and the dispersed phase. No extra surfactant is needed to promote emulsification.