Physicists probe quark‑gluon plasma temperatures, helping paint more detailed picture of big bang

Frank Geurts is a professor of physics and astronomy at Rice and co-spokesperson of the RHIC STAR collaboration.
Photo Credit: Jeff Fitlow/Rice University.

A research team led by Rice University physicist Frank Geurts has successfully measured the temperature of quark-gluon plasma (QGP) at various stages of its evolution, providing critical insights into a state of matter believed to have existed just microseconds after the big bang, a scientific theory describing the origin and evolution of the universe. 

The study addresses the long-standing challenge of measuring the temperature of matter under extreme conditions where direct access is impossible. By using thermal electron-positron pairs emitted during ultrarelativistic heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in New York, the researchers have decoded the thermal profile of QGP. 

Temperature measurements existed previously but have been plagued by several complications such as whether they were of the QGP phase or biased by a Doppler-like effect from the large velocity fields pushing such effective temperatures.

“Our measurements unlock QGP’s thermal fingerprint,” said Geurts, a professor of physics and astronomy and co-spokesperson of the RHIC STAR collaboration. “Tracking dilepton emissions has allowed us to determine how hot the plasma was and when it started to cool, providing a direct view of conditions just microseconds after the universe’s inception.” 

A promising target for multiple sclerosis

The image depicts a neuron with its axon insulated by segments of the myelin sheath. The visible degradation and fragmentation of that sheath represent the demyelination process that is characteristic of multiple sclerosis. This process disrupts the neuron's ability to transmit signals efficiently, leading to the neurological symptoms associated with the condition.
Image Credit: Scientific Frontline / AI generated

A team from UNIGE and HUG has discovered a subgroup of immune cells particularly involved in the disease, paving the way for more precise treatments and avoiding certain side effects.

Multiple sclerosis, which affects around one in 500 people in Switzerland, is an autoimmune disease in which immune cells attack the central nervous system, causing irreversible damage. Current treatments involve blocking the immune system to prevent it from attacking the body. Although effective, these drugs can trigger potentially serious infections. A team from the University of Geneva (UNIGE) and Geneva University Hospitals (HUG), in collaboration with the University of Pennsylvania, has identified a subtype of immune cells in newly diagnosed patients that may have a decisive role in disease progression.  A treatment targeting these cells specifically could effectively control the disease while avoiding certain side effects. These findings have been published in the journal Annals of Neurology.

Metamaterials can stifle vibrations with intentional complexity

This 3-D printed “kagome tube” can passively isolate vibrations using its complex, but deliberate, structure.
Image Credit: James McInerney, Air Force Research Laboratory

In science and engineering, it’s unusual for innovation to come in one fell swoop. It’s more often a painstaking plod through which the extraordinary gradually becomes ordinary.

But we may be at an inflection point along that path when it comes to engineered structures whose mechanical properties are unlike anything seen before in nature, also known as mechanical metamaterials. A team led by researchers at the University of Michigan and the Air Force Research Laboratory, or AFRL, have shown how to 3D print intricate tubes that can use their complex structure to stymy vibrations.

Such structures could be useful in a variety of applications where people want to dampen vibrations, including transportation, civil engineering and more. The team’s new study, published in the journal Physical Review Applied, builds on decades of theoretical and computational research to create structures that passively impede vibrations trying to move from one end to the other.

New advances to boost regeneration and plasticity of brain neurons

The study is led by Professor Daniel Tornero and researcher Alba Ortega , from the Faculty of Medicine and Health Sciences and the Institute of Neurosciences of the University of Barcelona
Photo Credit: Courtesy of University of Barcelona

The brain’s mechanisms for repairing injuries caused by trauma or degenerative diseases are not yet known in detail. Now, a study by the University of Barcelona describes a new strategy based on stem cell therapy that could enhance neuronal regeneration and neuroplasticity when this vital organ is damaged. The results reveal that the use of brain-derived neurotrophic factor (BDNF), combined with stem cell-based cell therapies, could help in the treatment of neurodegenerative diseases or brain injuries.

Combining cell therapy with BDNF production

BDNF is a protein that is synthesized mainly in the brain and plays a key role in neuronal development and synaptic plasticity. Several studies have described its potential to promote neuronal survival and growth, findings that are now extended by the new study.

“The findings indicate that BDNF can promote the maturation and increase the activity of neurons generated in the laboratory from donor skin cells. The skin cells must first be reprogrammed to become induced pluripotent stem cells (iPSCs), and then differentiated to obtain neuronal cultures,” says Daniel Tornero, from the UB’s Department of Biomedicine and the CIBER Area for the Neurodegenerative Diseases (CIBERNED).

In this way, the study combines cell therapy with the production of BDNF in the same cells. This study confirms the beneficial effects of this growth factor in neuronal cultures derived from human stem cells, the same cells that are used in cell therapy to treat, for example, stroke in animal models.

Study links wind-blown dust from receding Salton Sea to reduced lung function in area children

Researchers with the UC Irvine-led study sample dust at the southern edge of the Salton Sea. Joe C. Wen School of Population & Public Health
Photo Credit: Courtesy of University of California, Irvine

Children living near the Salton Sea, in Southern California’s desert region of Imperial County, are experiencing poorer lung function than children exposed to less wind-blown dust, according to a new study led by researchers at the University of California, Irvine’s Joe C. Wen School of Population & Public Health.

They found that higher dust exposure – measured in hours per year – was linked to lower lung function, with the negative effects most pronounced among children living closest to the lake. The work, published in the American Journal of Respiratory and Critical Care Medicine, marks one of the first investigations to directly link dust events from a drying saline lake to measurable declines in children’s respiratory health.

A federal grant from the National Institute of Environmental Health Sciences and the Southern California Environmental Health Sciences Center funded the research in partnership with the Imperial Valley community-based organization Comite Civico del Valle.

The tides are changing for white dwarfs

Impression of the 6.9 minute double white dwarf binary J1539+5027, composed of a tidally heated white dwarf (yellow) and its more compact companion (blue). It is about to start mass transferring.
 Image Credit: KyotoU / Lucy McNeill

White dwarfs are the compact remnants of stars that have stopped nuclear burning, a fate that will eventually befall our sun. These extremely dense objects are degenerate stars because their structure is counterintuitive: the heavier they are, the smaller they are.

White dwarfs often form binary systems, in which two stars orbit one another. The majority of these are ancient even by galactic standards, and have cooled to surface temperatures of about 4,000 degrees Kelvin. However, recent studies have revealed a class of short period binary systems in which the stars orbit each other faster than once per hour. Contrary to theoretical models, these stars are inflated to twice the size as expected due to surface temperatures of 10 to 30 thousand degrees Kelvin.

Binding power of trapped water demonstrated for the first time

Water molecules are a driving force in the formation of molecular bonds, such as in proteins.
Image Credit: INT, KIT

Water is everywhere – it covers most of the earth, circulates in the human body and can be found in even the smallest molecular niches. But what happens if water does not flow freely but is trapped in such structures? Researchers at the Karlsruhe Institute of Technology (KIT) and Constructor University in Bremen have proven for the first time that "locked" water can influence its environment and strengthen the bond between molecules. This finding could open new avenues for the development of drugs and materials.

Some of the water on Earth is found in tiny nooks and crannies – enclosed in molecular pockets, such as protein binding sites or synthetic receptors. Whether this water behaves neutrally in the presence of other molecules or influences their binding has so far been controversial. "Water molecules usually interact most strongly with each other. However, experimental data showed that water behaves unusually in such narrow pockets", says Dr. Frank Biedermann from KIT's Institute of Nanotechnology. "We have now been able to provide the theoretical basis for these observations and prove that the water in the molecular pockets is energetically tense."

Russian Physicists Found a Way to Speed Up the Process of Developing Solar Panels

According to Ivan Zhidkov, this method allows for the quick selection of only promising materials.
 Photo Credit: Rodion Narudinov

Physicists at Ural Federal University and their colleagues from the Institute of Problems of Chemical Physics of the Russian Academy of Science (IPCP RAS) have found a way to significantly reduce the thousands of hours required for developing perovskite solar panel technology. Scientists have proposed a method that allows us  to determine in a few hours whether solar panels will fail quickly or if the development is promising with a potentially long service life. The test results were published in the journal Physica B: Condensed Matter.

Perovskite films are promising energy converters for various photoelectronic devices, such as solar cells, LEDs, and photodetectors. They have excellent optoelectronic properties and can be grown relatively easily at a low production cost.

Geologists discover the first evidence of 4.5-billion-year-old “proto-Earth”

“This is maybe the first direct evidence that we’ve preserved the proto Earth materials,” says Nicole Nie. An artist’s illustration shows a rocky proto Earth bubbling with lava.
Image Credit: MIT News; iStock
(CC BY-NC-ND 4.0)

Scientists at MIT and elsewhere have discovered extremely rare remnants of “proto-Earth,” which formed about 4.5 billion years ago, before a colossal collision irreversibly altered the primitive planet’s composition and produced the Earth as we know today. Their findings, reported today in the journal Nature Geosciences, will help scientists piece together the primordial starting ingredients that forged the early Earth and the rest of the solar system.

Billions of years ago, the early solar system was a swirling disk of gas and dust that eventually clumped and accumulated to form the earliest meteorites, which in turn merged to form the proto-Earth and its neighboring planets.

In this earliest phase, Earth was likely rocky and bubbling with lava. Then, less than 100 million years later, a Mars-sized meteorite slammed into the infant planet in a singular “giant impact” event that completely scrambled and melted the planet’s interior, effectively resetting its chemistry. Whatever original material the proto-Earth was made from was thought to have been altogether transformed.

“Cocktails” of common pharmaceuticals in our waterways may promote antibiotic resistance

Photo Credit: Nana K.

New research has shown, for the first time, how mixtures of commonly used medications which end up in our waterways and natural environments might increase the development of antibiotic-resistant bacteria.

When humans or animals take medications, as much as 90 percent can pass through the body and into natural environments, via waste-water, or run-off from fields, ending up in the ocean. 

In the environment, this build-up of antibiotic medicines can accumulate to a strength sufficient to kill the bacteria that live there; this can result in bacteria evolving defenses that help them to survive these concentrations, which can mean they are also resistant to antibiotics used to treat them if they later infect humans. However, less is known about how build-up of other medicines also affects bacteria, and until now, scientists have largely investigated the effect of these medications on triggering this antibiotic resistance one-at-a-time.