Changes in these spin states can be detected using optically detected magnetic resonance (ODMR), which measures fluorescence changes under microwave radiation. NDs with NV centers are biocompatible and can be designed to interact with specific biological molecules, making them valuable tools for biological sensing. However, NDs used for bioimaging generally exhibit lower spin quality compared to bulk diamonds, resulting in reduced sensitivity and accuracy in measurements.

In a recent breakthrough, scientists from Okayama University in Japan developed nanodiamond sensors bright enough for bioimaging, with spin properties comparable to those of bulk diamonds. The study, published in ACS Nano, on 16 December 2024, was led by Research Professor Masazumi Fujiwara from Okayama University, in collaboration with Sumitomo Electric Company and the National Institutes for Quantum Science and Technology.

“This is the first demonstration of quantum-grade NDs with exceptionally high-quality spins, a long-awaited breakthrough in the field. These NDs possess properties that have been highly sought after for quantum biosensing and other advanced applications,” says Prof. Fujiwara.

Current ND sensors for bioimaging face two main limitations: high concentrations of spin impurities, which disrupt NV spin states, and surface spin noise, which destabilizes the spin states more rapidly. To overcome these challenges, the researchers focused on producing high-quality diamonds with very few impurities. They grew single-crystal diamonds enriched with 99.99% ¹²C carbon atoms and then introduced a controlled amount of nitrogen (30-60 parts per million) to create an NV center with about 1 part per million. The diamonds were crushed into NDs and suspended in water.

The resulting NDs had a mean size of 277 nanometers and contained 0.6-1.3 parts per million of negatively charged NV centers. They displayed strong fluorescence, achieving a photon count rate of 1500 kHz, making them suitable for bioimaging applications. These NDs also showed enhanced spin properties compared to commercially available larger NDs. They required 10-20 times less microwave power to achieve a 3% ODMR contrast, had reduced peak splitting, and demonstrated significantly longer spin relaxation times (T₁ = 0.68 ms, T₂ = 3.2 µs), which were 6 to 11 times longer than those of type-Ib NDs. These improvements indicate that the NDs possess stable quantum states, which can be accurately detected and measured with low microwave radiation, minimizing the risk of microwave-induced toxicity in cells.

To evaluate their potential for biological sensing, the researchers introduced NDs into HeLa cells and measured the spin properties using ODMR experiments. The NDs were bright enough for clear visibility and produced narrow, reliable spectra despite some impact from Brownian motion (random ND movement within cells). Furthermore, the NDs were capable of detecting small temperature changes. At temperatures around 300 K and 308 K, the NDs exhibited distinct oscillation frequencies, demonstrating a temperature sensitivity of 0.28 K/√Hz, superior to bare type-Ib NDs.

With these advanced sensing capabilities, the sensor has potential for diverse applications, from biological sensing of cells for early disease detection to monitoring battery health and enhancing thermal management and performance for energy-efficient electronic devices. “These advancements have the potential to transform healthcare, technology, and environmental management, improving quality of life and providing sustainable solutions for future challenges,” says Prof. Fujiwara.

The national survey found that discarded frozen items make up about 6% of wasted household food in the United States. Based on frozen food’s relatively small contribution to food waste and other findings in the study, researchers say urging consumers to stock their freezers might be one way to prevent premature disposal of food.

Results showed that though overall food waste remained high, there was a bright spot: Freezing food was associated with less food landing in the trash.

“We found that households with home freezing behaviors are more likely to have less food waste than other households,” said Lei Xu, first author of the paper and a postdoctoral scholar specializing in agricultural and food economics at The Ohio State University.

“Food waste is not just an economic loss — it also causes environmental damage because more than 90% of wasted food goes to the landfill, and this can produce greenhouse gas emissions,” Xu said. “The findings suggest that in the future, if we can encourage households to have home freezing behaviors, this small change in food storage habits can have a large environmental impact.”

Xu completed the study with graduate student Ran Li and senior author Brian Roe, professor in the Department of Agricultural, Environmental and Development Economics at Ohio State. The research was published recently in the British Food Journal.

Roe has been studying household food waste for years, but this is the first study to tease out where frozen food fits into the food waste picture. Recent estimates have suggested about 30% of food in the United States is wasted, but other research led by Roe suggests consumer food waste is trending upward.

“The fact that food waste is still increasing may suggest to policymakers that campaigns could be useful to educate households about balancing purchasing behavior and making the most of the food they buy,” Xu said.

The current study data comes from frozen food-related questions added to the summer 2022 wave of the U.S. National Household Food Waste Tracking Survey in which 1,067 households participated. Respondents were asked to estimate the percentage of all discarded food in the previous seven days that had been frozen and whether it was bought frozen or was unfrozen and placed in the freezer later. They also reported the typical frequency of buying frozen foods.

The responses indicated that 85% of U.S. households buy frozen foods and among those, 55% of participants reported they purchased frozen food to reduce waste. Frozen food purchasers were more likely to shop infrequently — two to three times per month — and were more likely to be living in households with annual income of under $50,000. The most common categories of discarded frozen foods were meat (20% of total frozen food waste), vegetables (22%) and potatoes and grains (15% each).

“Based on what we’re seeing among households, we still have space to increase awareness to save food by using freezing behavior,” Xu said.

Data showed a link between frequent home freezing and significantly less total food waste. Respondents most likely to freeze fresh items or extra food were aged 45 years and older and living in households of three or more people — a possible sign, the authors said, that consumers with a home freezing routine may be more experienced at managing meals for a group and motivated to avoid food waste.

What the team considered somewhat surprising — and enlightening — was the finding that about 30% more of wasted frozen food was discarded from the refrigerator than from the freezer.

“Thinking about why that happens, it might mean they don’t understand food storage techniques and don’t understand how long they should keep certain foods and where they should put it,” Xu said. “This suggests more explicit food storage instructions on food labels could educate consumers about how to correctly store foods to reduce waste.”

Trends in the data suggest that consumer education about the freezer’s role in saving food could make a difference economically and environmentally, Xu said, and also help address the societal problem of food insecurity experienced by 10% of U.S. households.

“Half of consumers buy frozen food to reduce waste. What about the other half?” she said. “We want to increase social awareness of how to save food, and explain how people use frozen food and home freezing techniques to save food. And freezing is one of the most accessible techniques because essentially all households have a refrigerator and freezer.”

This work was supported by the USDA National Institute of Food and Agriculture, the National Science Foundation and a gift from the Frozen Food Foundation that facilitated collection of a larger survey sample size.

Revolutionizing the Search for Habitability

The exploration of icy ocean worlds represents a new frontier in planetary science, focusing on understanding the potential for these environments to support life. Powell-Palm’s research addresses a fundamental question in this field: under what conditions can liquid water remain stable on these distant, frozen bodies? By defining and measuring the cenotectic, the absolute lowest temperature at which a liquid remains stable under varying pressures and concentrations, the team provides a critical framework for interpreting data from planetary exploration efforts.

This study combines Powell-Palm’s expertise in cryobiology — specifically the low-temperature thermodynamics of water — initially focused on medical applications like organ preservation for transplantation, with Journaux’s expertise in planetary science and high-pressure water-ice systems. Together, they developed a framework that bridges disciplines to tackle one of the most fascinating challenges in planetary science.

“With the launch of NASA Europa Clipper, the largest planetary exploration mission ever launched, we are entering a multi-decade era of exploration of cold and icy ocean worlds. Measurements from this and other missions will tell us how deep the ocean is and its composition,” said Journaux. “Laboratory measurements of liquid stability, and notably the lowest temperature possible (the newly-defined cenotectic), combined with mission results, will allow us to fully constrain how habitable the cold and deep oceans of our solar system are, and also what their final fate will be when the moons or planets have cooled down entirely.”

A Texas A&M Legacy of Innovation in Space Research

The research was conducted at Texas A&M and led by mechanical engineering graduate student Arian Zarriz. The work reflects Texas A&M’s deep expertise in water-ice systems and tradition of excellence in space research, which spans multiple disciplines. With the recent groundbreaking of the Texas A&M Space Institute, the university is poised to play an even larger role in space exploration, providing intellectual leadership for missions pushing the boundaries of human knowledge.

“The study of icy worlds is a particular priority for both NASA and the European Space Agency, as evidenced by the flurry of recent and upcoming spacecraft launches,” said Powell-Palm. “We hope that Texas A&M will help to provide intellectual leadership in this space.”

Looking Ahead

As planetary exploration missions, such as those targeting icy moons, continue to expand our understanding of the solar system, researchers at Texas A&M and beyond prepare to analyze the wealth of data they will provide. By combining experimental studies like those conducted by Powell-Palm and Journaux with the findings from these missions, scientists aim to unlock the secrets of cold, ocean-bearing worlds and evaluate their potential to harbor life.

Electron transfer, critical to processes such as cellular respiration and energy harvesting in plants, has long posed challenges to scientists due to the complex quantum interactions involved. Current computational techniques often fall short of capturing the full scope of these processes. The multidisciplinary team at Rice, including physicists, chemists and biologists, addressed these challenges by creating a programmable quantum system capable of independently controlling the key factors in electron transfer: donor-acceptor energy gaps, electronic and vibronic couplings and environmental dissipation.

Using an ion crystal trapped in a vacuum system and manipulated by laser light, the researchers demonstrated the ability to simulate real-time spin dynamics and measure transfer rates across a range of conditions. The findings not only validate key theories of quantum mechanics but also pave the way for novel insights into light-harvesting systems and molecular devices.

“This is the first time that this kind of model was simulated on a physical device while including the role of the environment and even tailoring it in a controlled way,” said lead researcher Guido Pagano, assistant professor of physics and astronomy. “It represents a significant leap forward in our ability to use quantum simulators to investigate models and regimes that are relevant for chemistry and biology. The hope is that by harnessing the power of quantum simulation, we will eventually be able to explore scenarios that are currently inaccessible to classical computational methods.”

The team achieved a significant milestone by successfully replicating a standard model of molecular electron transfer using a programmable quantum platform. Through the precise engineering of tunable dissipation, the researchers explored both adiabatic and nonadiabatic regimes of electron transfer, demonstrating how these quantum effects operate under varying conditions. Additionally, their simulations identified optimal conditions for electron transfer, which parallel the energy transport mechanisms observed in natural photosynthetic systems.

“Our work is driven by the question: Can quantum hardware be used to directly simulate chemical dynamics?” Pagano said. “Specifically, can we incorporate environmental effects into these simulations as they play a crucial role in processes essential to life such as photosynthesis and electron transfer in biomolecules? Addressing this question is significant as the ability to directly simulate electron transfer in biomolecules could provide valuable insights for designing new light-harvesting materials.”

The implications for practical applications are far-reaching. Understanding electron transfer processes at this level could lead to breakthroughs in renewable energy technologies, molecular electronics and even the development of new materials for quantum computing.

“This experiment is a promising first step to gain a deeper understanding of how quantum effects influence energy transport, particularly in biological systems like photosynthetic complexes,” said Jose N. Onuchic, study co-author, the Harry C. and Olga K. Wiess Chair of Physics and professor of physics and astronomy, chemistry and biosciences. “The insights we gain in this type of experiment could inspire the design of more efficient light-harvesting materials.”

Peter G. Wolynes, study co-author, the D.R. Bullard-Welch Foundation Professor of Science and professor of chemistry, biosciences and physics and astronomy, emphasized the broader significance of the findings: “This research bridges the gap between theoretical predictions and experimental verification, offering an exquisitely tunable framework for exploring quantum processes in complex systems.”

The team plans to extend its simulations to include more complex molecular systems such as those involved in photosynthesis and DNA charge transport. The researchers also hope to investigate the role of quantum coherence and delocalization in energy transfer, leveraging the unique capabilities of their quantum platform.

“This is just the beginning,” said Han Pu, co-lead author of the study and professor of physics and astronomy. “We are excited to explore how this technology can help unravel the quantum mysteries of life and beyond.”

The study’s other co-authors include graduate students Visal So, Midhuna Duraisamy Suganthi, Abhishek Menon, Mingjian Zhu and research scientist Roman Zhuravel.

This research was made possible thanks to the Welch Foundation Award C-2154, the Office of Naval Research Young Investigator Program (No. N00014-22-1-2282), a National Science Foundation CAREER Award (No. PHY-2144910), the Army Research Office (W911NF22C0012), the Office of Naval Research (No. N00014-23-1-2665), the NSF (PHY-2207283, PHY-2019745 and PHY-2210291) and the D. R. Bullard-Welch Chair at Rice (No. C0016). The authors acknowledge that this material is based upon work supported by the U.S Department of Energy, Office of Science, Office of Nuclear Physics under the Early Career Award No. DE-SC0023806. The isotopes used in this research were supplied by the U.S. Department of Energy Isotope Program managed by the Office of Isotope R&D and Production.

An international team of interdisciplinary researchers, including the Canepa Research Laboratory at the University of Houston, has developed a new type of material for sodium-ion batteries that could make them more efficient and boost their energy performance — paving the way for a more sustainable and affordable energy future.

The new material, sodium vanadium phosphate with the chemical formula Na_xV₂(PO₄)₃, improves sodium-ion battery performance by increasing the energy density — the amount of energy stored per kilogram — by more than 15%. With a higher energy density of 458 watt-hours per kilogram (Wh/kg) compared to the 396 Wh/kg in older sodium-ion batteries, this material brings sodium technology closer to competing with lithium-ion batteries.

“Sodium is nearly 50 times cheaper than lithium and can even be harvested from seawater, making it a much more sustainable option for large-scale energy storage,” said Pieremanuele Canepa, Robert Welch assistant professor of electrical and computer engineering at UH and lead researcher of the Canepa Lab. “Sodium-ion batteries could be cheaper and easier to produce, helping reduce reliance on lithium and making battery technology more accessible worldwide.”

From Theory to Reality

The Canepa Lab, which uses theoretical expertise and computational methods to discover new materials and molecules to help advance clean energy technologies, collaborated with the research groups headed by French researchers Christian Masquelier and Laurence Croguennec from the Laboratoire de Reáctivité et de Chimie des Solides, which is a CNRS laboratory part of the Université de Picardie Jules Verne, in Amiens France, and the Institut de Chimie de la Matière Condensée de Bordeaux, Université de Bordeaux, Bordeaux, France for the experimental work on the project. This allowed theoretical modelling to go through experimental validation.

The researchers created a battery prototype using the new material, Na_xV₂(PO₄)₃, demonstrating significant energy storage improvements. Na_xV₂(PO₄)₃, part of a group called “Na superionic conductors” or NaSICONs, is designed to let sodium ions move smoothly in and out of the battery during charging and discharging.

Unlike existing materials, it has a unique way of handling sodium, allowing it to work as a single-phase system. This means it remains stable as it releases or takes in sodium ions. This allows the NaSICON to remain stable during charging and discharging while delivering a continuous voltage of 3.7 volts versus sodium metal, higher than the 3.37 volts in existing materials.

While this difference may seem small, it significantly increases the battery’s energy density or how much energy it can store for its weight. The key to its efficiency is vanadium, which can exist in multiple stable states, allowing it to hold and release more energy.

“The continuous voltage change is a key feature,” said Canepa. “It means the battery can perform more efficiently without compromising the electrode stability. That’s a game-changer for sodium-ion technology.”

Possibilities for a Sustainable Future

The implications of this work extend beyond sodium-ion batteries. The synthesis method used to create Na_xV₂(PO₄)₃ could be applied to other materials with similar chemistries, opening new possibilities for advanced energy storage technologies. That could in turn, impact everything from more affordable, sustainable batteries to power our devices to help us transition to a cleaner energy economy.

“Our goal is to find clean, sustainable solutions for energy storage,” Canepa said. “This material shows that sodium-ion batteries can meet the high-energy demands of modern technology while being cost-effective and environmentally friendly.”

A paper based on this work was published in the journal Nature Materials. Ziliang Wang, Canepa’s former student and now a postdoctoral fellow at Northwestern University, and Sunkyu Park, a former student of the French researchers and now a staff engineer at Samsung SDI in South Korea, performed much of the work on this project.

According to the Centers for Disease Control and Prevention, heart failure affects nearly 7 million U.S. adults and is responsible for 14% of deaths per year. There is no cure for heart failure, though medications can slow its progression. The only treatment for advanced heart failure, other than a transplant, is pump replacement through an artificial heart, called a left ventricular assist device, which can help the heart pump blood.

“Skeletal muscle has a significant ability to regenerate after injury. If you’re playing soccer and you tear a muscle, you need to rest it, and it heals,” said Hesham Sadek, MD, PhD, director of the Sarver Heart Center and chief of the Division of Cardiology at the U of A College of Medicine — Tucson’s Department of Medicine. “When a heart muscle is injured, it doesn’t grow back. We have nothing to reverse heart muscle loss.”

Sadek led a collaboration between international experts to investigate whether heart muscles can regenerate. The study was funded through a grant awarded to Sadek by the Leducq Foundation Transatlantic Networks of Excellence Program, which brings together American and European investigators to tackle big problems.

The project began with tissue from artificial heart patients provided by colleagues at the University of Utah Health and School of Medicine led by Stavros Drakos, MD, PhD, a pioneer in left ventricular assist device-mediated recovery.

Jonas Frisén, MD, PhD, and Olaf Bergmann, MD, PhD, of the Karolinska Institute in Stockholm, led teams in Sweden and Germany and used their own innovative method of carbon dating human heart tissue to track whether these samples contained newly generated cells.

The investigators found that patients with artificial hearts regenerated muscle cells at more than six times the rate of healthy hearts.

“This is the strongest evidence we have, so far, that human heart muscle cells can actually regenerate, which really is exciting, because it solidifies the notion that there is an intrinsic capacity of the human heart to regenerate,” Sadek said. “It also strongly supports the hypothesis that the inability of the heart muscle to ‘rest’ is a major driver of the heart’s lost ability to regenerate shortly after birth. It may be possible to target the molecular pathways involved in cell division to enhance the heart’s ability to regenerate.”

Finding better ways to treat heart failure is a top priority for Sadek and the Sarver Heart Center. This study builds on Sadek’s prior research into rest and heart muscle regeneration.

In 2011, Sadek published a paper in Science showing that while heart muscle cells actively divide in utero, they stop dividing shortly after birth to devote their energy to pumping blood through the body nonstop, with no time for breaks.

In 2014, he published evidence of cell division in patients with artificial hearts, hinting that their heart muscle cells might have been regenerating.

These findings, combined with other research teams’ observations that a minority of artificial heart patients could have their devices removed after experiencing a reversal of symptoms, led him to wonder if the artificial heart provides cardiac muscles the equivalent of bedrest in a person recovering from a soccer injury.

“The pump pushes blood into the aorta, bypassing the heart,” he said. “The heart is essentially resting.”

Sadek’s previous studies indicated that this rest might be beneficial for the heart muscle cells, but he needed to design an experiment to determine whether patients with artificial hearts were actually regenerating muscles.

“Irrefutable evidence of heart muscle regeneration has never been shown before in humans,” he said. “This study provided direct evidence.”

Next, Sadek wants to figure out why only about 25% of patients are “responders” to artificial hearts, meaning that their cardiac muscle regenerates.

“It’s not clear why some patients respond and some don’t, but it’s very clear that the ones who respond have the ability to regenerate heart muscle,” he said. “The exciting part now is to determine how we can make everyone a responder, because if you can, you can essentially cure heart failure. The beauty of this is that a mechanical heart is not a therapy we hope to deliver to our patients in the future — these devices are tried and true, and we’ve been using them for years.”

Led by Texas A&M University graduate students Samere Zade of the biomedical engineering department and Ting-Ching Wang of the chemical engineering department, an article released by the Lele Lab has uncovered new details about the mechanism behind cancer progression.

Published in Nature Communications, the article explores the influence the mechanical stiffening of the tumor cell’s environment may have on the structure and function of the nucleus.

“Cancer has proven to be a difficult disease to treat. It is extremely complex and the molecular mechanisms that enable tumor progression are not understood,” said Dr. Tanmay Lele, joint faculty in the biomedical engineering and chemical engineering departments. “Our findings shed new light into how the stiffening of tumor tissue can promote tumor cell proliferation.”

In the article, researchers reveal that when a cell is faced with a stiff environment, the nuclear lamina — scaffolding that helps the nucleus keep its shape and structure — becomes unwrinkled and taut as the cell spreads on the stiff surface. This spreading causes yes-associated protein (YAP), the protein that regulates the multiplication of cells, to move to the nucleus.

That localization can cause increased cell proliferation, which may explain the rapid growth of cancer cells in stiff environments.

“The ability of stiff matrices to influence nuclear tension and regulate YAP localization could help explain how tumors become more aggressive and perhaps even resistant to treatment in stiffened tissues,” Zade said.

These findings build on Lele’s previous discovery that the cell nucleus behaves like a liquid droplet. In that work, researchers found that a protein in the nuclear lamina called lamin A/C helps maintain the nucleus’ surface tension. In the most recent study, it was found that reducing the levels of lamin A/C decreases the localization of YAP, in turn decreasing rapid cell proliferation.

“The protein lamin A/C plays a key role here — reducing it made cells less responsive to environmental stiffness, particularly affecting the localization of a key regulatory protein (YAP) to the nucleus,” Zade explained.

Although seemingly complex and specialized, Zade and Lele believe the broader implications of their discovery may guide future treatments for cancer.

“Uncovering how matrix stiffness drives nuclear changes and regulates key pathways, like YAP signaling, opens the door to developing therapies that target these mechanical pathways,” Zade explained. “Drugs or treatments could be designed to soften the tumor environment, disrupting the physical cues that help cancer cells thrive. Lamin A/C and related nuclear mechanics could become targets for cancer treatments.”

Moving forward, the Lele Lab aims to investigate the extent to which their discoveries apply to tumors derived from patients.

For this work, the Lele Lab was funded by the National Institutes of Health, the Cancer Prevention and Research Institute of Texas, and the National Science Foundation. Funding for this research is administered by the Texas A&M Engineering Experiment Station, the official research agency for Texas A&M Engineering.