Science Daily October 15, 2019 Cells often communicate using signaling molecules, which can travel only a short distance. Nevertheless, the cells can also communicate over large distances to spur collective action. An international team of researchers (USA – UT Houston, South Korea) used an engineered transcriptional circuit of combined positive and negative feedback loops in E. coli, which can periodically release two types of signaling molecules: activator and repressor. As the signaling molecules travel over a short distance, cells can only talk to their nearest neighbors. However, cell communities synchronize oscillatory gene expression in spatially extended systems if the transcriptional […]
Nanoscale manipulation of light leads to exciting new advancement
Eurekalert October 11, 2019 Researchers at the University of New Mexico studied arrays composed of silver nanoparticles placed in a repeating pattern. When the arrays are illuminated with light, each of the particles produces a strong response, which, in turn, results in enormous collective behaviors if all the particles can interact with one another. This happens at certain wavelengths of incident light, which are determined by the interparticle spacing of the array, and can result in electric fields that are thousands, or even tens of thousands, of times that of the light shined on the array. The strength of this […]
New electrolyte stops rapid performance decline of next-generation lithium battery
Science Daily October 10, 2019 Lithium-ion battery electrolytes currently contain a solvent mixture, with a dissolved lithium salt and often more than three organic additives. Researchers at Argonne National Laboratory have developed a unique electrolyte with a small amount of a second salt containing any one of several doubly or triply charged metal cations (Mg2+, Ca2+, Zn2+, or Al3+) they call MESA (mixed-salt electrolytes for silicon anodes). MESA gives silicon anodes increased surface and bulk stabilities, improving long-term cycling and calendar life. During charging, the metal cation additions in electrolyte solution migrate into the silicon-based anode along with the lithium […]
Refrigerator works by twisting and untwisting fibres
Physics World October 14, 2019 An international team of researchers (China, USA – UT Dallas, Georgia Southern University, industry, Brazil) studied the cooling effects of twist and stretch changes in twisted, coiled and supercoiled fibres of natural rubber, nickel-titanium and polyethylene fishing line. In each material, they observed a surface cooling as high as 16.4 °C, 20.8 °C, and 5.1 °C respectively. Analysis revealed changes in molecular structures associated with the transition from low to high entropy phases. They built a device from a three-ply nickel-titanium wire cable, which cooled a stream of running water by as much as 7.7 […]
Scientists unwind mystery behind DNA replication
Science Daily October 17, 2019 Researchers at Cornell University have unraveled the mystery of how DNA’s double helix manage to replicate without being tangled up from a topological perspective. Using eukaryotes as their model system, they found that the intrinsic mechanical properties of the chromatin (a complex of DNA and proteins) determine how the chromatin fibers will entwine. This topology is crucial to the successful separation of newly replicated DNA: If the fibers twist too tightly too early, then the molecules are unable to properly segregate during cell division. They found that twisting a single chromatin fiber is much easier […]
Solving the mystery of quantum light in thin layers
Science Daily October 15, 2019 Single-photon emitters play a key role in present and emerging quantum technologies. Several recent measurements have established monolayer WSe2 as a promising candidate for a reliable single-photon source. Researchers in Austria have shown that the origin and underlying microscopic processes responsible for this quantum light effect are the subtle interaction of single atomic defects in the material and mechanical strain. Computer simulations show how the electrons are driven to specific places in the material, where they are captured by a defect, lose energy and emit a photon…read more. TECHNICAL ARTICLE
Unique sticky particles formed by harnessing chaos
Phys.org October 14, 2019 The soft dendritic particle materials with unique adhesive and structure-building properties can be created from a variety of polymers precipitated from solutions under special conditions. An international team of researchers (USA – North Carolina State University, the Netherlands, UK) used ‘liquid’ nanomanufacturing to convert most polymers into branched particles after dissolving the polymer and mixing the solution rapidly with another liquid. Rapid mixing in turbulent flow creates branched particles organized in a hierarchical way. The thinnest branches surrounding these particles form a corona of nanofibers that distributes their stickiness by van der Waals forces. The process […]
Vibration in one direction only
Phys.org October 10, 2019 Researchers in the Netherlands created a robotic mechanical metamaterial wherein they used local control loops to break reciprocity at the level of the interactions between the unit cells. They showed theoretically and experimentally that first-of-their-kind spatially asymmetric standing waves at all frequencies and unidirectionally amplified propagating waves emerge. These findings realize the mechanical analogue of the non-Hermitian skin effect. They significantly advance the field of active metamaterials for Hermitian physics and open avenues to channel mechanical energy in unprecedented ways. Non-reciprocal transmission of motion is potentially highly beneficial to a wide range of applications, ranging from […]
Weaving quantum processors out of laser light
Science Daily October 17, 2019 The approach taken by an international team of researchers (Japan, Australia, USA – University of New Mexico) starts with extreme scalability, built in from the very beginning, because the processor, called a cluster state is made of light. A cluster state is a large collection of entangled quantum components that performs quantum computations when measured in a particular way. To be useful for real-world problems, a cluster state must be both large enough and have the right entanglement structure. To make the cluster state, specially designed crystals convert ordinary laser light into quantum light called […]
The World Could Soon Run Out of a Crucial Resource And Nobody Is Talking About It
Science Alert October 7, 2019 Phosphorous is an essential mineral for all plants and animals on Earth, including humans. It is not a renewable element, and there are currently no known substitutes and there are very few areas in which it is mined. In a report a group of 40 international experts have warned that if nothing is done to conserve this crucial element, our planet might soon run out completely. The world is entirely unprepared for the looming phosphorous crisis. There is no collaboration or coordination on a global scale that takes the responsibility of governing the global P-resource, […]