Highlights •Tissue-resident macrophages abound in the mouse and human AV nodes •Connexin 43 connects macrophages with cardiomyocytes •Macrophages modulate the electrical activity of cardiomyocytes •Macrophages assist normal AV nodal conduction

Macrophages have a previously unrecognized role in helping the mammalian heart beat in rhythm. Massachusetts General Hospital researchers discovered that macrophages aggregate around central cardiac cells that regulate electrical impulses within the mouse heart, helping the cells conduct electricity. Mice that were genetically engineered to lack macrophages have irregular heartbeats, hinting that these immune cells may also play a role in heart disease.

“This work opens up a completely new view on electrophysiology; now, we have a new cell ty...

Graphene and gold make a better brain probe. Credit: DGIST

Brain electrodes record neural activity, and can help treat neural diseases like Parkinson’s and epilepsy. Interest is also growing in developing better brain-machine interfaces, in which electrodes can help control prosthetic limbs. Progress in these fields is hindered by limitations in electrodes, which are relatively stiff and can damage soft brain tissue. Designing smaller, gentler electrodes that still pick up brain signals is a challenge because brain signals are so weak. Typically, the smaller the electrode, the harder it is to detect a signal. However, a team from the Daegu Gyeongbuk Institute of Science & Technology in Korea developed new probes that are small, flexible and read brain signals clearly.

The probe consists of...

(Left to right): Postdoc Kyusang Lee, Professor Jeehwan Kim (sitting), and graduate students Samuel Cruz and Yunjo Kim. Credit: Jose-Luis Olivares/MIT

A new technique may vastly reduce the overall cost of wafer technology and enable devices made from more exotic, higher-performing semiconductor materials than conventional silicon. The new method uses graphene as a sort of ‘copy machine’ to transfer intricate crystalline patterns from an underlying semiconductor wafer to a top layer of identical material. In 2016, annual global semiconductor sales reached their highest-ever point, at $339 billion worldwide. In that same year, the semiconductor industry spent about $7...

This artist’s impression shows the exoplanet LHS 1140b, which orbits a red dwarf star 40 light-years from Earth and may be the new holder of the title ‘best place to look for signs of life beyond the Solar System’. Using ESO’s HARPS instrument at La Silla, and other telescopes around the world, an international team of astronomers discovered this super-Earth orbiting in the habitable zone around the faint star LHS 1140. This world is a little larger and much more massive than the Earth and has likely retained most of its atmosphere. Credit: ESO/spaceengine.org

Super-Earth LHS 1140b orbits in the habitable zone around a faint red dwarf star named LHS 1140, in the constellation of Cetus (The Sea Monster)...