ScienceAdviser (AAAS)

Researchers had been excited about a material called cerium magnesium hexaaluminate (CeMgAl₁₁O₁₉), which seemed to exhibit quantum properties in its liquid form. Many magnetic materials tend to exist in one of two states: ferromagnetic, where the magnetic moment, a quantum property of atoms, is aligned parallel and the substance is strongly magnetized, or antiferromagnetic, where the atoms are aligned oppositely and the substance is not magnetized. Scientists can determine which state a material exhibits when they bring it to near-absolute zero temperatures.

When researchers first looked at the elusive liquid CeMgAl₁₁O₁₉, it displayed a continuum of ferromagnetic and antiferromagnetic behavior: a sign the material exhibited both states in a way only quantum mechanics could describe. But additional tests showed scientists that they had been fooled.

Bombarding CeMgAl₁₁O₁₉ with neutrons revealed that the material didn’t exhibit a true continuum, but was “choosing” between different magnetic states. The team thinks the material’s boundary between its ferromagnetic and antiferromagnetic states is weaker than in other traditional materials, giving it a near-quantum look. “This is a new state of matter that, to our knowledge, we are the first to describe ,” said author Pengcheng Dai in a statement.

Polystyrene, one of the most widely used plastic polymers, is also one of the hardest to break down. Some insect species, such as mealworms, can digest small amounts of this material, but they aren’t particularly efficient. In a new study, scientists wanted to find out if the cockroach Blaptica dubia could do better. In controlled feeding experiments, each cockroach consumed an average of six milligrams of polystyrene per day. Over 42 days, the critters managed to degrade nearly 55% of the plastic they had ingested —far higher than rates reported for other plastic-munching insects. The key to the cockroach’s success, researchers reported, is its remarkably cooperative relationship with the microbes living in its gut. These microbes break the polymer down into smaller, more manageable pieces, which the cockroach’s own enzymes can then convert to energy.

“Plastic degradation in insects is not merely a microbial phenomenon, but a fully integrated metabolic collaboration,” study corresponding author Shan-Shan Yang explained in a statement. Setting a bunch of cockroaches loose on the world’s garbage heap is, of course, a terrible idea, but the discovery could help scientists develop other biological strategies for dealing with plastic waste.

In a study published in Science, researchers explored whether astrocytes could be engineered to remove these plaques more efficiently . Borrowing a strategy from cancer immunotherapy, they equipped astrocytes with chimeric antigen receptors, or CARs—synthetic receptors that allow cells to recognize a specific target. The engineered CAR-astrocytes were designed to bind amyloid-β and trigger engulfment when the protein was detected. In laboratory tests, the modified cells readily internalized amyloid aggregates. The researchers then delivered the CAR constructs into the brains of mice using a viral vector that selectively targets astrocytes.

In a mouse model of Alzheimer’s disease, the engineered astrocytes accumulated around plaques and increased amyloid clearance. In some animals treated early, a single intervention prevented much of the plaque buildup that typically appears later in life. However, the team didn’t see a lessening of the behavioral symptoms of the disease, which mirrors the inconsistent cognitive benefits seen with anti-amyloid-β antibodies in clinical trials , wrote Jake Boles and David Gate in a related Perspective. Perhaps, they posit, amyloid plaques aren’t the best treatment target.

Still, the work provides a proof of concept that the brain’s support cells can be genetically programmed to remove harmful proteins; it also “helps to establish a foundation for increasingly innovative CAR strategies in [Alzheimer’s],” Boles and Gate added. “Together, these findings position CAR engineering as a scalable and tunable strategy for treating neurodegenerative disease,” the authors concluded.

With contributions from Hannah Richter, Phie Jacobs, and Ana Georgescu

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