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Besides particles like sterile neutrinos, axions and weakly interacting massive particles (WIMPs), a leading candidate for the cold dark matter of the universe are primordial black holes—black holes created from extremely dense conglomerations of subatomic particles in the first seconds after the Big Bang.

Primordial black holes (PBHs) are classically stable, but as shown by Stephen Hawking in 1975, they can evaporate via , radiating nearly like a blackbody. Thus, they have a lifetime; it’s proportional to the cube of their initial mass. As it’s been 13.8 billion years since the Big Bang, only PBHs with an initial mass of a trillion kilograms or more should have survived to today.

However, it has been suggested that the lifetime of a black hole might be considerably longer than Hawking’s prediction due to the memory burden effect, where the load of information carried by a black hole stabilizes it against evaporation.

More than ten years ago, researchers at Rice University led by materials scientist Boris Yakobson predicted that boron atoms would cling too tightly to copper to form borophene, a flexible, metallic two-dimensional material with potential across electronics, energy and catalysis. Now, new research shows that prediction holds up, but not in the way anyone expected.

Unlike systems such as graphene on , where atoms may diffuse into the substrate without forming a distinct alloy, the in this case formed a defined 2D copper boride ⎯ a new compound with a distinct atomic structure. The finding, published in Science Advances by researchers from Rice and Northwestern University, sets the stage for further exploration of a relatively untapped class of 2D materials.

“Borophene is still a material at the brink of existence, and that makes any new fact about it important by pushing the envelope of our knowledge in materials, physics and electronics,” said Yakobson, Rice’s Karl F. Hasselmann Professor of Engineering and professor of materials science and nanoengineering and chemistry. “Our very first theoretical analysis warned that on copper, boron would bond too strongly. Now, more than a decade later, it turns out we were right ⎯ and the result is not , but something else entirely.”

Much of the world’s lithium occurs in salty waters with fundamentally different chemistry than other naturally saline waters like the ocean, according to a study published on May 23 in Science Advances. The finding has implications for lithium mining technologies and wastewater assessment and management.

Lithium is a critical mineral in the renewable energy sector. About 40% of global lithium production comes from large pans, called salars, in the central Andes Mountains in South America and the Tibetan Plateau in Asia. In these arid, high-altitude regions, lithium exists below surface salt deposits, dissolved in extremely saline water called .

“We discovered that the pH of brines in these regions is almost entirely driven by boron, unlike seawater and other common saline waters. This is a totally different geochemical landscape, like studying an extraterrestrial planet,” said Avner Vengosh, distinguished professor of environmental quality and Chair of the Division of Earth and Climate Sciences at Duke University’s Nicholas School of the Environment, who oversaw the research.

A large team of astronomers and astrophysicists affiliated with several institutions in China has discovered a binary star system, where one of the stars is a millisecond pulsar and the other is made mostly of helium. In their paper published in the journal Science, the group describes how they discovered that a pulsar under study since 2020 had a companion star—one that was gravitationally bound to it.

Researchers on the team first spotted the back in May of 2020, and soon thereafter noticed that not only did it spin incredibly fast, but for one-sixth of its orbit, its radiation emissions were blocked. That suggested an object was passing between it and Earth. Over the next four years, the team studied the apparent binary system to learn more about its characteristics and confirm that there truly was a second star.

Pulsars are a type of neutron star that emit beams of radiation from their poles. They appear to pulse as viewed from Earth due to their spinning—the radiation signal can only be seen when one of the poles is pointed directly at the Earth.

Researchers at the First Affiliated Hospital of Chongqing Medical University in China have uncovered a sharply rising burden of skin cancer in older adults driven largely by population growth and affecting men twice as often.

Skin cancer already ranks among the costliest malignancies to treat, and an aging world means more time for ultraviolet damage to accumulate. Previous research shows older patients now make up nearly three-quarters of new cases, yet global data capturing the full scope and trend in those over 65 remains scarce.

In the study, “Burden of Skin Cancer in Older Adults From 1990 to 2021 and Modelled Projection to 2050,” published in JAMA Dermatology, researchers mined the Global Burden of Diseases 2021 registry to quantify how melanoma, , and affect adults aged 65 and older worldwide.

Most humans can recall specific events and past experiences for long periods of time. This capability, referred to as episodic memory, is known to be in great part supported by the activity of neurons in the hippocampus and medial temporal lobe.

Past neuroscience and psychology studies consistently found that is associative. This essentially means that remembering one past event, for instance a graduation, can in many cases prompt people to also remember other related events, such as a party that celebrated the graduation.

Researchers at Biología Molecular y Neurociencias (IFIByNE)-CONICET and the University of Buenos Aires recently carried out a new study exploring the possibility that the reactivation of specific episodic memories does not only help to strengthen those memories, but also the memories of other related events or experiences.

A breakthrough study, led by scientists at Waipapa Taumata Rau, University of Auckland, has uncovered how daylight can boost the immune system’s ability to fight infections.

The team focused on the most abundant immune cells in our bodies, called neutrophils, which are a type of white blood cell. These cells move quickly to the site of an infection and kill invading bacteria.

The researchers used zebrafish, a small freshwater fish, as a , because its is similar to ours and the fish can be bred to have transparent bodies, making it easy to observe biological processes in real time.

Researchers from Nagoya City University, Tohoku University, and other institutions have used numerical simulations to replicate how a peculiar mineral texture called barred olivine forms inside chondrules—millimeter-sized spherical particles found in meteorites. These chondrules are considered time capsules from the early solar system, and barred olivine is a rare mineral texture not seen in Earth rocks.

The study is published in Science Advances.

Associate Professor Hitoshi Miura of Nagoya City University and the team were the first to reproduce this texture using and theoretically elucidate its formation process.

Our cells rely on microscopic highways and specialized protein vehicles to move everything—from positioning organelles to carting protein instructions to disposing of cellular garbage. These highways (called microtubules) and vehicles (called motor proteins) are indispensable to cellular function and survival.

The dysfunction of motor proteins and their associated proteins can lead to severe neurodevelopmental and neurodegenerative disorders. For example, the dysfunction of Lis1, a partner protein to the motor protein , can lead to the rare fatal birth defect lissencephaly, or “smooth brain,” for which there is no cure. But therapeutics that target and restore dynein or Lis1 function could change those dismal outcomes—and developing those therapeutics depends on thoroughly understanding how dynein and Lis1 interact.

New research from the Salk Institute and UC San Diego captured short movies of Lis1 “turning on” dynein. The movies allowed the team to catalog 16 shapes that the two proteins take as they interact, some of which have never been seen before. These insights will be foundational for designing future therapeutics that restore dynein and Lis1 function, since they shine a light on precise locations where drugs could interact with the proteins.

Blue phosphorescent OLEDs can now last as long as the green phosphorescent OLEDs already in devices, University of Michigan researchers have demonstrated, paving the way for further improving the energy efficiency of OLED screens.

“This moves the blues into the domain of green lifetimes,” said Stephen Forrest, the Peter A. Franken Distinguished University Professor of Electrical Engineering and corresponding author of the study in Nature Photonics.

“I can’t say the problem is completely solved—of course it’s not solved until it enters your display—but I think we’ve shown the path to a real solution that has been evading the community for two decades.”