. Scientific Frontline

Tuesday, March 5, 2024

Aluminum nanoparticles make tunable green catalysts

Aaron Bayles is a Rice University doctoral alum, a postdoctoral researcher at the National Renewable Energy Laboratory and a lead author on a paper published in the Proceedings of the National Academy of Sciences.
Photo Credit: Courtesy of Aaron Bayles / Rice University

Catalysts unlock pathways for chemical reactions to unfold at faster and more efficient rates, and the development of new catalytic technologies is a critical part of the green energy transition.

The Rice University lab of nanotechnology pioneer Naomi Halas has uncovered a transformative approach to harnessing the catalytic power of aluminum nanoparticles by annealing them in various gas atmospheres at high temperatures.

According to a study published in the Proceedings of the National Academy of Sciences, Rice researchers and collaborators showed that changing the structure of the oxide layer that coats the particles modifies their catalytic properties, making them a versatile tool that can be tailored to suit the needs of different contexts of use from the production of sustainable fuels to water-based reactions.

“Aluminum is an earth-abundant metal used in many structural and technological applications,” said Aaron Bayles, a Rice doctoral alum who is a lead author on the paper. “All aluminum is coated with a surface oxide, and until now we did not know what the structure of this native oxide layer on the nanoparticles was. This has been a limiting factor preventing the widespread application of aluminum nanoparticles.”

Aluminum nanoparticles absorb and scatter light with remarkable efficiency due to surface plasmon resonance, a phenomenon that describes the collective oscillation of electrons on the metal surface in response to light of specific wavelengths. Like other plasmonic nanoparticles, the aluminum nanocrystal core can function as a nanoscale optical antenna, making it a promising catalyst for light-based reactions.

Juno Spacecraft Measures Oxygen Production on Jupiter's Moon, Europa

For the first time, SwRI scientists used the Jovian Auroral Distributions Experiment (JADE) instrument to definitively detect oxygen and hydrogen in the atmosphere of one of Jupiter's largest moons, Europa. NASA's Juno spacecraft, using its SwRI-developed instrument, made the measurements during a 2022 flyby of Europa.
Image Credit: Courtesy of NASA/JPL/University of Arizona

NASA’s Juno spacecraft has directly measured charged oxygen and hydrogen molecules from the atmosphere of one of Jupiter’s largest moons, Europa. According to a new study co-authored by SwRI scientists and led by Princeton University, these observations provide key constraints on the potential oxygenation of its subsurface ocean.

“These findings have direct implications on the potential habitability of Europa,” said Juno Principal Investigator Dr. Scott Bolton of SwRI, a co-author of the study. “This study provides the first direct in-situ measurement of water components existing in Europa’s atmosphere, giving us a narrow range that could support habitability.”

In 2022, Juno completed a flyby of Europa, coming as close as 352 kilometers to the moon. The SwRI-developed Jovian Auroral Distributions Experiment (JADE) instrument aboard Juno detected significant amounts of charged molecular oxygen and hydrogen lost from the atmosphere.

Harmful ‘forever chemicals’ removed from water with new electrocatalysis method

Per- and polyfluoroalkyl substances (PFAS) are often referred to as “forever chemicals” because they break down very slowly. Rochester scientists have developed nanocatalysts that can more affordably remediate a specific type of PFAS called Perfluorooctane sulfonate (PFOS).
Photo Credit: J. Adam Fenster / University of Rochester 

A novel approach using laser-made nanomaterials created from nonprecious metals could lay the foundation for globally scalable remediation techniques.

Scientists from the University of Rochester have developed new electrochemical approaches to clean up pollution from “forever chemicals” found in clothing, food packaging, firefighting foams, and a wide array of other products. A new Journal of Catalysis study describes nanocatalysts developed to remediate per- and polyfluoroalkyl substances, known as PFAS.

The researchers, led by assistant professor of chemical engineering Astrid Müller, focused on a specific type of PFAS called Perfluorooctane sulfonate (PFOS), which was once widely used for stain-resistant products but is now banned in much of the world for its harm to human and animal health. PFOS is still widespread and persistent in the environment despite being phased out by US manufacturers in the early 2000s, continuing to show up in water supplies.

How Does a River Breathe?

Scientists at Pacific Northwest National Laboratory have been studying processes that affect how rivers and streams breathe, particularly in the Columbia River Basin, to help prepare for future changes related to water quality and climate change. 
Photo Credit: Andrea Starr | Pacific Northwest National Laboratory

Take a deep breath.

Pay attention to how air moves from your nose to your throat before filling your lungs with oxygen.

As you exhale your breath, a mix of oxygen and carbon dioxide leaves your nose and mouth.

Did you know that streams and rivers “breathe” in a similar way?

The United States is home to more than 250,000 of these flowing bodies of water that connect to coastal zones and oceans. They vary in size, from small streams to large rivers, but all take in oxygen and give off carbon dioxide and other greenhouse gases like methane. 

Over recent years, a team of scientists led by Pacific Northwest National Laboratory (PNNL) has been immersed in crucial research around the processes and interactions that contribute to greenhouse gas dynamics. Their work focuses on whole networks of streams and rivers, as well as the land surrounding these systems.       

Their work also includes factors that can disturb how streams and rivers breathe. Some of these disturbances happen beyond streams, like wildfires, but still impact how streams breathe by changing how material enters streams. Understanding these impacts is key to addressing challenges related to water quality, global carbon cycling, and climate change.

Possible ‘Trojan Horse’ found for treating stubborn bacterial infections

Transmission electron microscope (TEM) image of the bacterial cell with an extracellular vesicle attached.
Image Credit: Courtesy of Washington State University

Bacteria can be tricked into sending death signals to stop the growth of their slimy, protective homes that lead to deadly infections, a new study demonstrates.

The discovery by Washington State University researchers could someday be harnessed as an alternative to antibiotics for treating difficult infections. Reporting in the journal Biofilm, the researchers used the messengers, which they named death extracellular vesicles (D-EVs), to reduce growth of the bacterial communities by up to 99.99% in laboratory experiments.

“Adding the death extracellular vesicles to the bacterial environment, we are kind of cheating the bacteria cells,” said Mawra Gamal Saad, first author on the paper and a graduate student in WSU’s Gene and Linda Voiland School of Chemical Engineering and Bioengineering. “The cells don’t know which type of EVs they are, but they take them up because they are used to taking them from their environment, and with that, the physiological signals inside the cells change from growth to death.”

A Larger Area of Arctic Seafloor is Exposed to Sunlight

Photo Credit: © Ignacio Garrido

Most of the sunlight reaching the Arctic Ocean is reflected by sea ice, shielding ocean ecosystems from light. As Arctic sea ice continues to melt, larger areas of the ocean and seafloor become exposed to sunlight, potentially allowing more photosynthesis to occur and making the Arctic Ocean more productive. However, this does not seem to be occurring uniformly across the Arctic Ocean.

Over the past 25 years, the amount of summer Arctic sea ice has diminished by more than 1 million square kilometers. As a result, vast areas of the Arctic Ocean are now, on average, ice free in summer. Scientists are closely monitoring how this impacts sunlight availability and marine ecosystems in the far north.

Many questions arise when such large areas become ice-free and can receive sunlight. A prevailing paradigm suggests that the Arctic Ocean is rapidly becoming more productive as sunlight becomes more abundant in the marine environment. However, it is unclear how ecosystems will evolve in response to increasing sunlight availability and how different parts of the marine ecosystem will be affected, says Karl Attard, a marine scientist and Associate Professor at the Department of Biology.

Attard has led an international research team investigating sunlight availability and photosynthetic production on the understudied Arctic seafloor. Their study has been published in the scientific journal Proceedings of the National Academy of Sciences (PNAS).

Groundbreaking survey reveals secrets of planet birth around dozens of stars

This research brings together observations of more than 80 young stars that might have planets forming around them in spectacular discs. This small selection from the survey shows 10 discs from the three regions of our galaxy observed in the papers. V351 Ori and V1012 Ori are located in the most distant of the three regions, the gas-rich cloud of Orion, some 1600 light-years from Earth. DG Tau, T Tau, HP Tau, MWC758 and GM Aur are located in the Taurus region, while HD 97048, WW Cha and SZ Cha can be found in Chamaeleon I, all of which are about 600 light-years from Earth.  The images shown here were captured using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument mounted on ESO’s Very Large Telescope (VLT). SPHERE’s state-of-the-art extreme adaptive optics system corrects for the turbulent effects of Earth’s atmosphere, yielding crisp images of the discs around stars. The stars themselves have been covered with a coronagraph — a circular mask that blocks their intense glare, revealing the faint discs around them.  The discs have been scaled to appear roughly the same size in this composition. 
Full Size Zoomable Image
Image Credit: ESO/C. Ginski, A. Garufi, P.-G. Valegård et al.

In a series of studies, a team of astronomers has shed new light on the fascinating and complex process of planet formation. The stunning images, captured using the European Southern Observatory's Very Large Telescope (ESO’s VLT) in Chile, represent one of the largest ever surveys of planet-forming discs. The research brings together observations of more than 80 young stars that might have planets forming around them, providing astronomers with a wealth of data and unique insights into how planets arise in different regions of our galaxy.

“This is really a shift in our field of study,” says Christian Ginski, a lecturer at the University of Galway, Ireland, and lead author of one of three new papers published today in Astronomy & Astrophysics. “We’ve gone from the intense study of individual star systems to this huge overview of entire star-forming regions.”

How artificial intelligence learns from complex networks

Multi-layered, so-called deep neural networks are highly complex constructs that are inspired by the structure of the human brain. However, one shortcoming remains: the inner workings and decisions of these models often defy explanation.
Image Credit: Brian Penny / AI Generated

Deep neural networks have achieved remarkable results across science and technology, but it remains largely unclear what makes them work so well. A new study sheds light on the inner workings of deep learning models that learn from relational datasets, such as those found in biological and social networks.

Graph Neural Networks (GNNs) are artificial neural networks designed to represent entities—such as individuals, molecules, or cities—and the interactions between them. These networks have practical applications in various domains; for example, they predict traffic flows in Google Maps and accelerate the discovery of new antibiotics within computational drug discovery pipelines.

GNNs are notably utilized by AlphaFold, an acclaimed AI system that addresses the complex issue of protein folding in biology. Despite these achievements, the foundational principles driving their success are poorly understood.

A recent study sheds light on how these AI algorithms extract knowledge from complex networks and identifies ways to enhance their performance in various applications.

Scientists Have Created Organic Films to Charge Cardiac Pacemakers

The resulting films have high biocompatibility.
Photo Credit: Andrei Ushakov

UrFU scientists, together with colleagues from the University of Aveiro (Portugal), have succeeded in obtaining biocompatible crystalline films. They have high piezoelectric properties - they generate an electric current under mechanical or thermal stress. This property will be useful in the design of elements for invasive medical devices, such as pacemakers. Detailed information about the films obtained and the new method of their synthesis has been published by the scientists in ACS Biomaterials Science & Engineering

"We have succeeded in obtaining films from diphenylalanine that have high piezoelectric properties comparable to their inorganic counterparts. Under mechanical or thermal stress, these films generate electricity. The use of such films will be particularly useful for making invasive cardiac pacemakers - devices that reside inside the human body. When the heart moves or beats, these films generate electricity, which is stored in the pacemaker's batteries. Energy storage devices based on such materials could solve the problem of replacing depleted batteries and reduce the number of surgical procedures," explains Denis Alikin, Head of the Laboratory of Functional Nanomaterials and Nanodevices at the UrFU Research Institute of Physics and Applied Mathematics.

Monday, March 4, 2024

New dressing robot can ‘mimic’ the actions of care-workers

The world's first bimanual dressing robot system mimics how caregivers assist humans in dressing.
Photo Credit: Courtesy of University of York

Scientists have developed a new robot that can ‘mimic’ the two-handed movements of care-workers as they dress an individual.

Until now, assistive dressing robots, designed to help an elderly person or a person with a disability get dressed, have been created in the laboratory as a one-armed machine, but research has shown that this can be uncomfortable for the person in care or impractical. 

To tackle this problem, Dr Jihong Zhu, a robotics researcher at the University of York’s Institute for Safe Autonomy, proposed a two-armed assistive dressing scheme, which has not been attempted in previous research, but inspired by caregivers who have demonstrated that specific actions are required to reduce discomfort and distress to the individual in their care.

It is thought that this technology could be significant in the social care system to allow care-workers to spend less time on practical tasks and more time on the health and mental well-being of individuals. 

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