Evasive quantum phenomenon makes debut in routine tabletop experiment

Researchers recently confirmed the presence of the axial Higgs mode, a particle excitation depicted here as a golden sphere. They used Raman spectroscopy, in which an incoming electric field, shown in blue, was coupled with the particle and subsequently scattered into a different frequency, shown in red.
 Credit: Ioannis Petrides and Prineha Narang/Harvard University

A Quantum Science Center-supported team has captured the first-ever appearance of a previously undetectable quantum excitation known as the axial Higgs mode.

This mode manifests as a low-energy excitation in rare-earth tellurides, a class of quantum materials notable for exhibiting charge density wave, or CDW, interactions. This behavior refers to arrangements of interacting electrons in quantum materials that form specific patterns and correlations.

Unlike the regular Higgs mode, which is produced by a Higgs mechanism that provides mass to fundamental particles in the Standard Model of Particle Physics, the axial Higgs mode is visible at room temperature. This characteristic enables more efficient and cost-effective experiments for manipulating quantum materials for various applications – including next-generation memory storage and opto-electronic devices – which would otherwise require extremely cold temperatures.

The team responsible for these results, which are published in Nature, was led by researchers at Boston College and includes scientists from Harvard University, Princeton University, University of Massachusetts Amherst, Yale University, University of Washington and the Chinese Academy of Sciences.

New delivery method allows slow-release of broader array of peptide drugs in the body

Schwendeman Lab.
Image credit: Michigan Photography

A new study from the University of Michigan describes one of the first entirely new drug delivery microencapsulation approaches in decades.

Microencapsulation in biodegradable polymers allows drugs such as peptide therapeutics to be released over time in the body.

Peptides are molecules in the body that are composed of short chains of amino acids, and include messengers, growth factors and well-known hormones such as insulin. Because of their larger size and structure, peptide drugs are rarely given by mouth and must be injected. Microencapsulation is one way to decrease the time needed between injections.

One slow-release delivery method for peptide drugs is to encapsulate them within the type of resorbable polymers often used as dissolving sutures, said study co-author Steven Schwendeman, professor of pharmaceutical sciences and biomedical engineering.

However, development of polymer dosage forms for delivery of certain peptide drugs has been difficult because the currently available methods to microencapsulate the peptide molecules in the polymer require organic solvents and complex manufacturing.

Altered gene helps plants absorb more carbon dioxide, produce more useful compounds

Hiroshi Maeda

Every day, plants around the world perform an invisible miracle. They take carbon dioxide from the air and, with the help of sunlight, turn it into countless chemicals essential to both plants and humans.

Some of these chemicals, known as aromatic compounds, are the starting material for a wealth of useful medications, such as aspirin and morphine. Yet, many of these chemicals come from fossil fuels because it’s hard to get plants to make enough of them to harvest economically. Others are essential human nutrients and can only be obtained through our food since our bodies are unable to make them.

In new work, scientists at the University of Wisconsin–Madison identified a way to release the brakes on plants’ production of aromatic amino acids by changing, or mutating, one set of genes. The genetic change also caused the plants to absorb 30% more carbon dioxide than normal, without any ill effect on the plants.

If scientists could add a trait like this to crops or drug-producing plants, it could help them produce more chemicals naturally while reducing greenhouse gases in the atmosphere.

“We’ve long been interested in this aromatic amino acid pathway because it’s one of the major plant pathways that transform carbon fixed by photosynthesis into medicines, food, fuels, and materials,” says Hiroshi Maeda, a UW–Madison professor of botany who led the new research. “Now for the first time, we’ve discovered how to regulate the key control knob plants use to turn up production of this pathway.”

Uncovering a novel way to bring to Earth the energy that powers the sun and stars

From left: PPPL physicists Ken Hill, Lan Gao, and Brian Kraus; image of the National Ignition Facility
 Collage courtesy of Kiran Sudarsanan

Scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) has uncovered critical new details about fusion facilities that use lasers to compress the fuel that produces fusion energy. The new data could help lead to the improved design of future laser facilities that harness the fusion process that drives the sun and stars.

Fusion combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — that generates massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power to generate electricity.

Major experimental facilities include tokamaks, the magnetic fusion devices that PPPL studies; stellarators, the magnetic fusion machines that PPPL also studies and have recently become more widespread around the world; and laser devices used in what are called inertial confinement experiments.

Rapid-fire fast radio burst shows hot space between galaxies

The Five-hundred-meter Aperture Spherical radio Telescope, known as FAST, in Ghizou province, southwest China, where Fast Radio Burst 20190520B was discovered, is considered the spiritual successor to the now-defunct, Cornell-built Arecibo Observatory in Puerto Rico.
Credit: Shami Chatterjee

A rare and persistent rapid-fire fast radio burst source – sending out an occasional and informative cosmic ping from more than 3.5 billion light years away – now helps to reveal the secrets of the broiling hot space between the galaxies.

What excites astronomers about the repeating fast radio bursts (FRBs) – since they only burst once, generally speaking – is that these quick-fire surges provide a pathway for scientists to comprehend the perplexing, mysterious and million-degree intergalactic medium.

This work, “A Repeating Fast Radio Burst Associated with a Persistent Radio Source,” was published June 8 in Nature, by an international group of scientists led by Chinese and Cornell astronomers.

“Examining the intergalactic medium is really hard,” said co-author Shami Chatterjee, Ph.D. ’03, principal research scientist in astronomy in the College of Arts and Sciences. “The intergalactic medium is difficult to probe, which is why fast radio bursts are exciting. The bursts let us study the properties of the intergalactic medium.”

Joining Chatterjee on the Nature paper are James M. Cordes, the George Feldstein Professor of Astronomy (A&S) and Stella K. Ocker, a doctoral student in astronomy.

Human skin can be damaged by exposure to thirdhand smoke and electronic cigarette spills

Prue Talbot (left) and her former graduate student Giovanna Pozuelos.
Credit: UCR/Stan Lim

A University of California, Riverside, study has found that dermal exposure to nicotine concentrations found in thirdhand smoke, or THS, and electronic cigarette spills may damage the skin.

THS, of which nicotine is a major component, is created when exhaled smoke and smoke emanating from the tip of burning cigarettes settles on surfaces such as clothing, hair, furniture, and cars. Not strictly smoke, THS refers to the residues left behind by smoking. Electronic cigarette spills are e-liquid spills that may occur by leaky electronic cigarette products or when consumers and vendors mix e-liquids for refillable electronic cigarettes.

Study results appear in Atmosphere, a journal.

“We found dermal contact with nicotine may impair wound healing, increase susceptibility to skin infections due to a decrease in immune response, and cause oxidative stress in skin cells,” said Giovanna Pozuelos, who graduated earlier this year from UC Riverside with a doctoral degree in cell, molecular, and developmental biology.

The study was performed using EpiDermTM, a 3D model of the human epidermis, and cultured human keratinocytes. Keratinocytes are epidermal cells that produce keratin, the protein found in hair and fingernails. The researchers exposed EpiDermTM for 24 hours to different nicotine concentrations typically found in THS environments and electronic cigarette spills. The researchers then proceeded to identify processes and pathways altered by the exposure. They investigated nicotine’s effect on cellular organelles, mitochondria, and peroxisomes — organelles containing enzymes involved in many metabolic reactions.

Zinc Found to Play an Important Role in Lung Fibrosis

Paul Noble, MD

Cedars-Sinai research shows targeting a newly identified molecular Pathway with a common mineral could help reverse lung damage in Idiopathic Pulmonary Fibrosis patients

Investigators from the Women’s Guild Lung Institute at Cedars-Sinai have discovered that zinc, a common mineral, may reverse lung damage and improve survival for patients with a deadly age-related condition known as idiopathic pulmonary fibrosis (IPF).

Their findings, published in The Journal of Clinical Investigation, have the potential to change the landscape of treatment for patients with this disease, which most often affects those over age 50.

“This study has the potential to be a game changer,” said Paul Noble, MD, chair of the Department of Medicine, director of the Women’s Guild Lung Institute and co-senior author of the study. “We identified a root cause of IPF-related lung damage and a potential therapeutic target that might restore the lungs’ ability to heal themselves.”

Idiopathic pulmonary fibrosis, or IPF, affects 100,000 people in the U.S. and has no known cause. The condition, which leads to scarring of the lungs, called fibrosis, and progressive breathing difficulty, has no cure, and most patients die or require a lung transplant within three to five years of diagnosis. The incidence of IPF rises dramatically with age and affects men more often than women.

Through this research, Cedars-Sinai investigators found that stem cells lining the air sacs in the lungs of patients with IPF lose their ability to process zinc, which is known to have a role in the growth of cells and healing damaged tissue.

Earth Is Safe: Astronomers Conducted a "Space Exercise"

Today, the distance from Apophis to Earth is 0.88 astronomical units, or almost 132 million km.
Photo: Eyes on Asteroids / NASA

More than 100 astronomers from 18 countries conducted a "space exercise". They joined their efforts to simulate the approach to the Earth of a dangerous asteroid and to estimate the probability of collision. Employees of the Kourovka Astronomical Observatory of the UrFU also took part in the project: Eduard Kuznetsov, Dmitry Glamazda, Galina Kaiser, Aleksandr Perminov and Yulia Vibe. The study was led by experts from NASA and the International Asteroid Warning Network (IAWN). The results are published in the Planetary Science Journal.

The asteroid Apophis, which was approaching Earth from December 2020 to March 2021, was taken as a sample of the potential threat. According to the "exercises", all data on Apophis were "forgotten", and scientists had to detect the asteroid again, determine its coordinates, speed, trajectory and many other parameters, as well as estimate the probability of collision with the Earth, the strength (energy) of the hit, which can cause an asteroid like Apophis. By common efforts it was even possible to determine the general composition of the asteroid and the properties of its surface. It was crucial, however, to understand how far in advance scientists were able to detect and how quickly they could classify extraterrestrial bodies that could pose a danger to the Earth.

International team visualizes properties of plant cell walls at nanoscale

Scattering-type scanning near-field optical microscopy, a nondestructive technique in which the tip of the probe of a microscope scatters pulses of light to generate a picture of a sample, allowed the team to obtain insights into the composition of plant cell walls.
Credit: Ali Passian/ORNL, U.S. Dept. of Energy

To optimize biomaterials for reliable, cost-effective paper production, building construction, and biofuel development, researchers often study the structure of plant cells using techniques such as freezing plant samples or placing them in a vacuum. These methods provide valuable data but often cause permanent damage to the samples.

A team of physicists including Ali Passian, a research scientist at the Department of Energy’s Oak Ridge National Laboratory, and researchers from the French National Centre for Scientific Research, or CNRS, used state-of-the-art microscopy and spectroscopy methods to provide nondestructive alternatives. Using a technique called scattering-type scanning near-field optical microscopy, the team examined the composition of cell walls from young poplar trees without damaging the samples.

But the team still had other obstacles to overcome. Although plant cell walls are notoriously difficult to navigate due to the presence of complex polymers such as microfibrils — thin threads of biomass that Passian describes as a maze of intertwined spaghetti strings — the team reached a resolution better than 20 nanometers, or about a thousand times smaller than a strand of human hair. This detailed view allowed the researchers to detect optical properties of plant cell materials for the first time across regions large and small, even down to the width of a single microfibril. Their results were published in Communications Materials.

Gravity-defying spike waves rewrite the rule book

The ‘spike wave’ created in the FloWave circular wave tank
Credit: University of Oxford

Researchers studying wave breaking have found that axisymmetric ‘spike waves' can far exceed limits that were previously thought to dictate the maximum height of ocean waves.

In a new study on ocean wave breaking, researchers have demonstrated that the breaking behavior of axisymmetric ‘spike waves’ is quite different to the long-established theories on the breaking of traveling waves.

Travelling waves break when waves become so steep that the crest is no longer stable. This leads to a breakdown of wave motion and energy loss. As a result, the height of the wave is limited by the breaking process.

‘Much of our understanding of wave breaking is routed in theories developed and experiments carried out in two dimensions when waves are moving in one direction,’ explained lead author Dr Mark McAllister, Department of Engineering Science, University of Oxford. ‘However, wave breaking in the ocean is a three-dimensional process.’