Now online! Structural steps along the assembly of proteasome storage granules—membraneless organelles that form in response to metabolic shifts in yeast—are visualized inside cells by cryo-electron tomography. Inactive 26S proteasomes oligomerize into trimers, which assemble into paracrystalline arrays that serve as reservoirs of fully assembled proteasomes under conditions of low energy, ready for reactivation when glucose is restored.
New simulations performed on a NASA supercomputer are providing scientists with the most comprehensive look yet into the maelstrom of interacting magnetic structures around city-sized neutron stars in the moments before they crash. The team identified potential signals emitted during the stars’ final moments that may be detectable by future observatories.
“Just before neutron stars crash, the highly magnetized, plasma-filled regions around them, called magnetospheres, start to interact strongly. We studied the last several orbits before the merger, when the entwined magnetic fields undergo rapid and dramatic changes, and modeled potentially observable high-energy signals,” said lead scientist Dimitrios Skiathas, a graduate student at the University of Patras, Greece, who is conducting research for the Southeastern Universities Research Association in Washington at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
A paper describing the findings is published in the The Astrophysical Journal.
Researchers from Drexel University who discovered a versatile type of two-dimensional conductive nanomaterial called MXene nearly a decade and a half ago, have now reported on a process for producing its one-dimensional cousin: the MXene nanoscroll. The group posits that these materials, which are 100 times thinner than human hair yet more conductive than their two-dimensional counterparts, could be used to improve the performance of energy storage devices, biosensors and wearable technology.
Their finding, published in the journal Advanced Materials, offers a scalable method for producing the nanoscrolls from a MXene precursor with precise control over their shape and chemical structures.
“Two-dimensional morphology is very important in many applications. However, there are applications where 1D morphology is superior,” said Yury Gogotsi, Ph.D., Distinguished University and Bach professor in Drexel’s College of Engineering, who was a corresponding author of the paper.
Ordinary matter, when cooled, transitions from a gas into a liquid. Cool it further still, and it freezes into a solid. Quantum matter, however, can behave very differently. In the early 20th century, researchers discovered that when helium is cooled, it transitions from a seemingly ordinary gas into a so-called superfluid. Superfluids flow without losing any energy, among other quantum quirks, like an ability to climb out of containers.
What happens when you cool a superfluid down even more? The answer to this question has eluded physicists since they first started asking it half a century ago.
A team of researchers at Monash University has uncovered a powerful new way to engineer exotic quantum states, revealing a robust and tunable three-dimensional flat electronic band in an ultrathin kagome metal, an achievement long thought to be nearly impossible. The study, “3D Flat Band in Ultra-Thin Kagome Metal Mn₃Sn Film,” by M. Zhao, J. Blyth, T. Yu and collaborators appears in Advanced Materials.
The discovery centers on Mn₃Sn films just three nanometers thick. Despite their extreme thinness, these films host a 3D flat band that spans the entire momentum space, offering an unprecedented platform for exploring strongly correlated quantum phases and designing future low-energy electronic technologies.
“Until now, 3D flat bands had only been observed in a few bulk materials with special lattice geometries,” said Ph.D. candidate and co-lead author James Blyth, from the Monash University School of Physics and Astronomy.
NASA is announcing the availability of its newest supercomputer, Athena, an advanced system designed to support a new generation of missions and research projects. The newest member of the agency’s High-End Computing Capability project expands the resources available to help scientists and engineers tackle some of the most complex challenges in space, aeronautics, and science.
Housed in the agency’s Modular Supercomputing Facility at NASA’s Ames Research Center in California’s Silicon Valley, Athena delivers more computing power than any other NASA system, surpassing the capabilities of its predecessors, Aitken and Pleiades, in power and efficiency. The new system, which was rolled out in January to existing users after a beta testing period, delivers over 20 petaflops of peak performance – a measurement of the number of calculations it can make per second – while reducing the agency’s supercomputing utility costs.
“Exploration has always driven NASA to the edge of what’s computationally possible,” said Kevin Murphy, chief science data officer and lead for the agency’s High-End Computing Capability portfolio at NASA Headquarters in Washington. “Now with Athena, NASA will expand its efforts to provide tailored computing resources that meet the evolving needs of its missions.”
A UCLA-led, multi-institution research team has discovered a metallic material with the highest thermal conductivity measured among metals, challenging long-standing assumptions about the limits of heat transport in metallic materials.
Published this week in Science, the study is led by Yongjie Hu, a professor of mechanical and aerospace engineering at the UCLA Samueli School of Engineering. The team reported that metallic theta-phase tantalum nitride conducts heat nearly three times more efficiently than copper or silver, the best conventional heat-conducting metals.
Thermal conductivity describes how efficiently a material can carry heat. Materials with high thermal conductivity are essential for removing localized hot spots in electronic devices, where overheating limits performance, reliability and energy efficiency. Copper currently dominates the global heat-sink market, accounting for roughly 30% of commercial thermal-management materials, with a thermal conductivity of about 400 watts per meter-kelvin.
In a new study, an international group of researchers has found that chiral phonons can create orbital current without needing magnetic elements—in part because chiral phonons have their own magnetic moments. Additionally, this effect can be achieved in common crystal materials. The work has potential for the development of less expensive, energy-efficient orbitronic devices for use in a wide array of electronics.
All electronic devices are based upon the charge of an electron, and electrons have three intrinsic properties: spin, charge and orbital angular momentum. While researchers have long explored the use of spin as a more efficient way to create current, the field of orbitronics —based upon using an electron’s orbital angular momentum, rather than its spin, to create a current flow—is still relatively new.
“Traditionally it has been technically challenging to generate orbital current,” says Dali Sun, co-corresponding author on the study published in Nature Physics. Sun is a professor of physics and member of the Organic and Carbon Electronics Lab (ORaCEL) at North Carolina State University.
A research team affiliated with UNIST has reported a novel synthesis strategy that enables the direct intercalation of a wide range of metal cations into the interlayer spaces of layered titanate (LT) structures. This approach opens new possibilities for designing highly tailored catalysts and energy storage materials for specific industrial applications.
Professors Seungho Cho (Department of Materials Science and Engineering), Kwangjin An (School of Energy and Chemical Engineering), and Hu Young Jeong (Graduate School of Semiconductor Materials and Devices Engineering) at UNIST, in collaboration with Professor Jeong Woo Han from Seoul National University, report this advancement in Advanced Materials.
