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Enantioresolution turns bright but racemic gold-silver clusters into circularly polarized emitters

Chiral metal clusters that emit circularly polarized light often face a trade-off between photoluminescence efficiency and luminescence dissymmetry. A study published in the journal Advanced Optical Materials tested whether highly luminescent racemic carbon-centered gold(I)-silver(I) clusters could be converted into bright CPL emitters by enantioresolution with chiral donor ligands.

Researchers have shown that treating highly luminescent but racemic carbon-centered gold(I)-silver(I) clusters with chiral oxygen-donor ligands can separate them into mirror-image forms (enantiomers) that retain strong photoluminescence while gaining the ability to emit circularly polarized light.

A phosphate-protected enantiomer pair achieved a photoluminescence quantum yield of 0.92÷0.93 and the largest luminescence dissymmetry factor (|glum | = 0.008) among the clusters tested. Incorporating the cluster into a composite device with a cholesteric liquid crystal raised the measured device-level |glum | to 1.25.

Rotating light pattern reveals laser frequency in a single image

An international team of physicists has developed a new method for determining the precise color of laser light using an image that rotates as the laser’s frequency shifts.

The finding could offer a new way to ensure that lasers are ‘locked’ to the frequencies needed by technologies that rely on them, from GPS positioning to quantum sensors. It could also spur developments in spectroscopy, magnetometry and quantum communications.

In a new paper published in the journal Optica, the University of Glasgow-led team describes how it devised a way to determine the frequency of a laser beam in a single snapshot.

Revisiting a Young Isaac Newton

Isaac Newton is typically portrayed as a solitary scientist with intense focus who was obsessed with power and deeply egotistical. But a new book by Caltech historians Jed Buchwald and Mordechai Feingold takes a deeper look at Newton’s life in the two decades leading up to the 1687 publication of his groundbreaking text, Principia Mathematica, when he was 44. Using newly digitized scans of Newton’s early writings, Buchwald and Feingold uncover a portrait of the young polymath as a curious and social scholar whose interests were often fleeting.

How the moon and sun may trigger slow earthquakes on Earth

While not quite a fatal attraction, the gravitational pull of the moon and sun creates tiny stresses on Earth that can trigger events known as slow earthquakes. These are movements along fault lines (fault slips) that release their energy gradually over much longer periods than ordinary quakes. Although they have been observed, exactly how these celestial bodies trigger them has been a relatively tough nut to crack.

So a team of geoscientists led by Yishuo Zhou at PSL University in Paris created computer models of these fault lines to find out what is going on.

Overlooked lakes may be helping to keep the Northern Hemisphere cool

Lakes may cover only a small fraction of Earth’s surface, but new research suggests they play a bigger role in regulating the planet’s climate than previously recognized. By reflecting sunlight back into space when covered in snow and ice, lakes in the Northern Hemisphere have a stronger cooling effect than the surrounding land.

Dr. Sarah Cooley of Duke University and colleagues say their results highlight an overlooked part of Earth’s climate system that could be better represented in climate models, which scientists use to understand how the planet responds to changing environmental conditions.

How bumblebees keep up with a flower that won’t stay still

Landing on a moving target is a challenge for all flying animals. For bumblebees, a flower swaying in the wind creates an erratic landing pad. Reaching it means matching its sideways motion while continuing to face it. When the bee turns in flight, its view of the flower changes, which complicates the feat.

In a new study, researchers Chenyao Wang and colleagues at Wageningen University and Delft University of Technology placed a circular, flowerlike platform at a hive entrance, where bumblebees learned to land to return home. During the experiments, the flower model moved sideways through two complete cycles per second, traveling 2.5 centimeters (1 inch) to either side of its central position.

Three high-speed cameras captured 48 landing sequences. The team reconstructed the flights in three dimensions to separate two actions that happened together: moving sideways to follow the platform and turning to face it.

New device measures curved mirrors’ absolute shape to within 2 nanometers without touching them

Researchers at AIST have developed a device that measures the absolute surface profile of curved optical elements with high precision without touching them.

High-precision curved mirrors are used for light collection and wavefront control in extreme ultraviolet (EUV) lithography systems, synchrotron facilities, astronomical telescopes, gravitational wave detectors and more. The accuracy of their surface profiles significantly affects the performance of these devices.

During manufacturing, it is crucial to determine not only fine-scale surface topography but also the absolute surface profile, including information such as the radius of curvature. These measurements are then used to correct the surface profile. However, measuring the surface profile of curved mirrors with accuracy on the order of a few nanometers without damaging the surface has been difficult.

AI structure prediction speeds discovery of ‘molecular glues’ to treat disease

A Baylor College of Medicine-led team has developed a strategy that combines the analysis of thousands of proteins with artificial intelligence to accelerate the discovery of small molecules called molecular glues to treat disease. Their approach, published in Nature Communications, has uncovered a new class of molecular glues that could neutralize harmful proteins linked to blood cancers and autoimmune diseases. The work also shows how AI-based structural modeling can help chemists optimize compounds well before experiments reveal how they work.

“Many scientists are increasingly exploring a new way to treat disease: Instead of blocking harmful proteins, they aim to eliminate them entirely. One promising approach uses molecular glues, which act like matchmakers inside cells,” said senior and co-corresponding author Dr. Jin Wang, director of the Center for NextGen Therapeutics and Michael E. DeBakey, M.D., endowed professor in pharmacology and in the Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology at Baylor. Wang also is a member of Baylor’s Dan L Duncan Comprehensive Cancer Center.

“These compounds bring a target protein to the cell’s natural protein-disposal machinery, which destroys the target. In this study, our team discovered and optimized a new class of molecular glues that selectively remove a protein called VAV1, an important regulator of immune cell function that has been linked to blood cancers and autoimmune diseases,” Wang said.

Students develop electric car that captures particulate matter while driving

VENTRA is a new sustainable concept car developed by the student team TU/ecomotive. The electric vehicle captures particulate matter generated by tires and brakes while driving, encourages a more sustainable driving style and produces less particulate matter itself. With this concept, the students aim to raise awareness of the dangers of particulate matter and inspire the industry to develop new solutions.

The students are focusing on a form of vehicle emissions that often receives less attention. Although electric cars do not produce exhaust emissions, fine particles are still released while driving because of wear on tires, brakes and the road surface. “No exhaust emissions does not necessarily mean no emissions,” says team manager Tim Spencer. According to him, the problem may be greater with electric cars because they are generally heavier and exert more force on the tires when accelerating.

Microplastics clog liver immune cells, driving fat buildup in mice

Microplastics appear capable of significantly impairing the function of phagocytes in the liver, at least in mice. In turn, this disrupts the metabolism of this vital organ and increases the build-up of fat inside it. These key findings from a joint German-Austrian study led by the University of Bonn, have now been published in the journal Nature Metabolism.

Phagocytes, literally “eating cells,” or “macrophages” to give them their scientific name, are immune cells that reside in virtually every organ of the body. They play an important protective role, looking out for bacteria, diseased cells and foreign matter, engulfing them and breaking them down into their component parts. In addition, they help the organs they live in function properly.

“From working with cell cultures, we’ve known for several years that macrophages also take up microplastics,” explains Professor Elvira Mass from the LIMES Institute at the University of Bonn. “We wanted to know whether that’s also the case in a living organism and, if so, what effect it has.”

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