ScienceDaily: Matter & Energy News

Over time, concrete cracks and crumbles. Well, most concrete cracks and crumbles. Structures built in ancient Rome are still standing, exhibiting remarkable durability despite conditions that would devastate modern concrete. One of these structures is the large cylindrical tomb of first-century noblewoman Caecilia Metella. New research shows that the quality of the concrete of her tomb may exceed that of her male contemporaries' monuments because of the volcanic aggregate the builders chose and the unusual chemical interactions with rain and groundwater with that aggregate over two millennia.

A conundrum has long stumped polymer scientists: Elastic polymers can be stiff, or they can be tough, but they can't be both. This stiffness-toughness conflict is a challenge for scientists developing polymers that could be used in applications including tissue regeneration, bioadhesives, bioprinting, wearable electronics, and soft robots. Researchers have resolved that long-standing conflict and developed an elastomer that is both stiff and tough.

Blue mussels (Mytilus edulis) spend their days being buffeted by crashing waves. They manage to stay tethered to the rocks or their fellow mussels thanks to a highly effective underwater glue they produce. Because achieving adhesion in the presence of water is so challenging, scientists who are interested in producing effective adhesives for use in wet environments (e.g., for surgical or dental treatments) have turned to mussels for inspiration. After a decade of work in the area, a team has succeeded in uncovering the cellular mechanisms by which mussels fabricate underwater adhesives.

For the first time, researchers have been able capture images providing unprecedented details of how particles behave in a liquid suspension when the phenomenon known as shear thickening takes place. The work allows us to directly understand the processes behind shear thickening, which had previously only been understood based on inference and computational modeling.

Researchers describe how large cyclic molecules can be used for the synthesis of big metallic complexes with two or more metal atoms.

Proteins drive nearly all biological functions and insight into their workings is essential for pharmaceutical developments. But now, a pair of scientists from Japan have found that our fundamental understanding of a characteristic of proteins that is key to their proper functioning -- the mechanism by which their structures fold -- has been flawed. These new findings call for a re-assessment of all research and applications based on the earlier theory.

Lead-based vacancy centers in diamonds that form after high-pressure and high-temperature treatment are ideal for quantum networks, find scientists. The modified crystal system could also find applications in spintronics and quantum sensors.