Dental flosser for at-home stress monitoring

American Chemical Society

LinkedIn
MessageWhatsAppEmail

 

image: 

This dental floss pick has a sensor that can assess your stress level.

view more 

Credit: Atul Sharma

Over time, stress and anxiety can build to a point where life’s challenges become overwhelming and cause physical effects. Now, in ACS Applied Materials & Interfaces, researchers report a dental floss pick with a built-in sensor that could monitor stress as part of a daily routine. The device, which accurately senses levels of the stress hormone cortisol in minutes, could help users recognize when it’s time to get help.

Unchecked chronic stress can lead to health conditions such as heart disease and mental disorders. Catching rising stress levels early is important, but daily blood tests at a doctor’s office aren’t feasible for most people, and self-reported questionnaires are subjective. That’s why researchers are developing point-of-care tests that measure cortisol levels in saliva, which mirror the hormone’s concentrations in blood. Although the saliva tests are promising, many of them require people to remember to perform the complicated analyses or use a bulky mouthguard. In addition, the anxiety of performing a test can cause stress levels to spike. So, Sameer Sonkusale and colleagues took a completely different approach by integrating a cortisol sensor into a dental floss pick — something many people use every day.

The team’s dental pick features floss that collects saliva. The floss is connected to a microfluidic thread that transports saliva to a flexible electrochemical sensor embedded in the handle of the pick. The sensor is made of an electrode with an electropolymerized molecularly imprinted polymer (eMIP) on it. The researchers made the eMIP by embossing cortisol molecules into an electrically conductive film and then removing them — similar to a shoe leaving an impression in wet cement. During tests, salivary cortisol binds in the impressions, decreasing the electrical current flowing through the sensor, which produces a signal that is wirelessly transmitted to a mobile device. The strength of the signal corresponds to the amount of cortisol in the saliva. Finally, the analyzed saliva moves to an adsorbent waste pad next to the sensor and the pick can be discarded.

The device takes around 10 minutes to report a result. In tests with cortisol-spiked artificial saliva, the dental pick was sensitive enough to detect small increases in cortisol that could be early indicators of stress. In tests with real human saliva samples, the dental flosser performed just as well as the commonly used ELISA saliva test for measuring levels of cortisol.

Overall, the researchers say that this device is one of the best-performing cortisol sensors reported so far, and it could someday be modified to detect other clinically important salivary molecules.

The authors acknowledge funding from the National Science Foundation and Congressionally Directed Medical Research Program. The human saliva samples used in this work were collected per the approved protocol from the Tufts University Institutional Review Board.

###

The American Chemical Society (ACS) is a nonprofit organization founded in 1876 and chartered by the U.S. Congress. ACS is committed to improving all lives through the transforming power of chemistry. Its mission is to advance scientific knowledge, empower a global community and champion scientific integrity, and its vision is a world built on science. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

Registered journalists can subscribe to the ACS journalist news portal on EurekAlert! to access embargoed and public science press releases. For media inquiries, contact newsroom@acs.org.

Note: ACS does not conduct research but publishes and publicizes peer-reviewed scientific studies.

Follow us: Facebook | LinkedIn | Instagram

---

Journal

ACS Applied Materials & Interfaces

DOI

10.1021/acsami.5c02988 

Article Title

“Saliva-Sensing Dental Floss: An Innovative Tool for Assessing Stress via On-Demand Salivary Cortisol Measurement with Molecularly Imprinted Polymer and Thread Microfluidics Integration”

 

Academy award-nominated movie helps researchers identify brain region biased towards drug cues and treatment effects in individuals with heroin use disorder

The Mount Sinai Hospital / Mount Sinai School of Medicine

Facebook

XLinkedInWeChatBlueskyMessageWhatsApp\\Email

 

image: 

Graphic representation of the study.

view more 

Credit: Mount Sinai Health System

Mount Sinai researchers have found  that a brain region that is implicated extensively in value-based decision-making and craving in people with heroin use disorder – known as the orbitofrontal cortex (OFC) –  shows synchronized responses biased towards drug content, outcompeting other typical subjects of attention and motivation, in a group of individuals with heroin use disorder who watched “Trainspotting,” the Academy Award-nominated 1996 movie about people who use heroin in Scotland.

Importantly, the research team also found that the OFC’s bias toward drug stimuli was significantly reduced in people who underwent treatment/abstinence from drugs. The study results appear in the May issue of Brain.

A core process in drug addiction is maladaptive salience attribution—the process by which the brain selectively focuses motivated attention on certain stimuli and gives them a sense of importance, often at the expense of other stimuli—to drug cues. In other words, with repeated drug use, drug-related stimuli, cues, and context begin to outcompete other typical rewards and reinforcers—such as food, sex, or social connection—for attention and motivation. In effect, for individuals with drug addiction, their reinforcing environment begins to “shrink” to become narrowly focused on drugs.

Previous neuroimaging studies of this phenomenon have looked at brain responses to repeated presentations of images of different types of stimuli, such as drugs, drug paraphernalia, or food. In this study, the Mount Sinai research team assessed salience attribution to drug cues using “Trainspotting” as a more realistic, dynamic, and complex stimulus. Using a movie with a narrative centered on the lived experience of individuals with heroin use disorder (or any psychiatric disorder) for this type of research has never been done before.

“In drug addiction, a drug-themed movie can function like a highly engaging mirror of a real-world drug environment in a way static images cannot, evoking brain processes that are closer to the lived experience of the person, which thereby improves the ecological validity of our functional magnetic resonance imaging (fMRI) studies of the brain,” said Rita Goldstein, PhD, Professor of Psychiatry, and Neuroscience, at the Icahn School of Medicine at Mount Sinai and senior author of the paper. “By imaging the brain while study participants watched the movie, we found several brain regions that responded to the movie in a manner that was biased towards the drug content in individuals with heroin use disorder. In particular, when watching the movie, the OFC responded to drug cues at the expense of other scenes. This result highlights the challenges of daily experience for individuals with substance use disorder.”

For the study, 30 inpatient individuals with heroin use disorders (24 male) and 25 healthy controls (16 male) watched the first 17 minutes of ”Trainspotting” while in an fMRI scanner at baseline and at follow-up after 15 weeks of inpatient treatment that encompassed standard of care with medications for opioid use disorder, relapse prevention and stress management, and group therapies (for the individuals with heroin use disorder). Individuals without addiction did not receive treatment, but the control group was also scanned twice, at baseline and 15 weeks later, to control for time and test-retest effects.

In analyzing these fMRI data, the research team adapted a reverse correlation method to identify the movie content that elicited synchronized fMRI responses in each group. They then measured the degree of shared bias towards drug content in the movie when both drug and non-drug stimuli were presented within this same dynamic narrative context. They also measured self-reported drug craving, which is a typical and well-validated treatment outcome that changes with abstinence and predicts clinical outcomes, in the individuals with substance use disorders.

“In addition to finding that the OFC showed synchronized responses that were biased towards drug content in the individuals with heroin use disorder, we were encouraged to find that with abstinence and treatment, there was recovery whereby this brain region normalized and responded less to the drug content,” said Greg Kronberg, PhD, postdoctoral fellow in the Department of Psychiatry at the Icahn School of Medicine at Mount Sinai and first author of the study. “Finding functional recovery in the OFC with just three months of treatment, with a link to reduced craving, was both surprising and very notable. It is the first evidence of such recovery that points towards avenues for improving treatment.”

“We did not find similar effect when using a static picture-based task, which suggests that movie fMRI, and especially using a movie tailored to the specific concerns of a unique patient population, is more sensitive to the effects of treatment and recovery in psychiatric research in general” added Dr. Goldstein.

The authors note some limitations of the study, including that it used only one movie and that all participants with heroin use disorder were in an inpatient treatment program and abstinent from drug use at the time of the study, so the researchers could not distinguish the contribution of abstinence itself vs. treatment for these recovery processes. Future studies are needed to validate these results with other movies, other substance use disorders, and other phases within the addiction cycle.

The Mount Sinai team is now developing a real-time neurofeedback protocol in which study participants are shown their brain activity in real time with the goal of training them to modulate activity towards a target value. They are testing whether such real-time neurofeedback, provided during watching of the drug-themed movie, could help facilitate recovery in people with substance use disorders. They are also running studies to test these methods with several other movies, where one goal is to use this naturalistic drug cue reactivity platform to test for menstrual phase differences in women with addiction.

About the Mount Sinai Health System
Mount Sinai Health System is one of the largest academic medical systems in the New York metro area, with 48,000 employees working across seven hospitals, more than 400 outpatient practices, more than 600 research and clinical labs, a school of nursing, and a leading school of medicine and graduate education. Mount Sinai advances health for all people, everywhere, by taking on the most complex health care challenges of our time—discovering and applying new scientific learning and knowledge; developing safer, more effective treatments; educating the next generation of medical leaders and innovators; and supporting local communities by delivering high-quality care to all who need it.

Through the integration of its hospitals, labs, and schools, Mount Sinai offers comprehensive health care solutions from birth through geriatrics, leveraging innovative approaches such as artificial intelligence and informatics while keeping patients’ medical and emotional needs at the center of all treatment. The Health System includes approximately 9,000 primary and specialty care physicians and 11 free-standing joint-venture centers throughout the five boroughs of New York City, Westchester, Long Island, and Florida. Hospitals within the System are consistently ranked by Newsweek’s® “The World’s Best Smart Hospitals, Best in State Hospitals, World Best Hospitals and Best Specialty Hospitals” and by U.S. News & World Report's® “Best Hospitals” and “Best Children’s Hospitals.” The Mount Sinai Hospital is on the U.S. News & World Report® “Best Hospitals” Honor Roll for 2024-2025.

For more information, visit https://www.mountsinai.org or find Mount Sinai on Facebook, Instagram, LinkedIn, X, and YouTube.

###

---

Journal

Brain

DOI

10.1093/brain/awae369 

Method of Research

Observational study

Subject of Research

People

Article Title

Shared orbitofrontal dynamics to a drug-themed movie track craving and recovery in heroin addiction

Article Publication Date

13-May-2025

 

These structures shrink when pulled

Discovery unlocks new exotic properties for soft robotics, smart devices, and more.

AMOLF

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Cuplifting: adding weight to the cup increases the tension—until suddenly, it lifts!

view more 

Credit: AMOLF

When you pull something—like a rubber band—you expect it to get longer. But what if it did the opposite? What if it suddenly shrunk instead? In a study published on April 14 in Proceedings of the National Academy of Sciences (PNAS), researchers from AMOLF and ARCNL have made this possible. They created structures that snap inward when pulled outward. This surprising behavior defies conventional understanding of materials and opens up exciting applications in soft robotics, smart devices, and vibration control systems.  

Countersnapping
“We’ve shown that mechanical systems can be designed to behave in ways that seem almost paradoxical” says Bas Overvelde, principal investigator of the Soft Robotic Matter Group. “This new kind of behavior - that we coin ‘countersnapping’ - has never been seen in experiments before. This could transform how we design everything from medical robotic devices to earthquake-resistant buildings.” 

Combining building blocks
To make this counterintuitive behavior happen, the team developed a clever design strategy: instead of trying to build the complex behavior all at once, they started with small, more simple parts and combined them in a specific way. The result? Structures that suddenly contract when pulled - something previously thought to be nearly impossible to achieve in practice. According to first author Paul Ducarme: “It’s like discovering a new building block for mechanical systems. It behaves in a completely unexpected way—but once you understand it, you can use it to do amazing things.” 

Applications
The researchers demonstrated that these countersnapping structures can lead to exotic properties that could potentially be useful in a range of applications. Examples include: 

• One-way sliding motion without motors or electronics — potentially useful in soft robots that need to move forward without slipping backward, such as medical robots navigating through the body. 

• Materials that switch stiffness on demand — ideal for wearable exosuits or prosthetics that need to be flexible during movement but stiffen instantly for support or safety. 

• Structures that dampen excessive vibration all by themselves — potentially lifesaving in systems like airplanes, wind turbines, or even buildings in earthquake-prone areas. 

Beyond using individual structures, the team also explored combining multiple structures together. “This opens new possibilities for metamaterials that act like computers”, says Martin van Hecke, principal investigator of the Mechanical Metamaterial group at AMOLF.  

Just the beginning
The researchers believe this is just the beginning. Much like traditional snapping is used in things like pop-up tents, snapping toys, and deployable space structures, countersnapping could find its way into a new generation of technologies that are smarter, faster, and more adaptive. 

These structures shrink when pulled [VIDEO] | 

When you pull something—like a rubber band—you expect it to get longer. But what if it did the opposite? This countersnapping material shows exotic behavior!

Building blocks of countersnapping material with exotic behavior.

Credit

AMOLF/Alberto Comoretto

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2423301122 

Method of Research

Experimental study

Article Title

Exotic mechanical properties enabled by countersnapping instabilities

Article Publication Date

13-May-2025

 

Professor challenges long-held assumptions of symmetry in physics

Mississippi State University

Facebook

XLinkedInWhatsAppEmail

 

image: 

Mississippi State Professor of Physics Dipangkar Dutta is a principal investigator on a groundbreaking experiment—revealing “symmetry” in physics doesn’t always behave as scientists once believed.

view more 

Credit: Beth Wynn, MSU Office of Public Affairs

STARKVILLE, Miss.—Mississippi State Professor of Physics Dipangkar Dutta is a principal investigator on a groundbreaking experiment—revealing “symmetry” in physics doesn’t always behave as scientists once believed—recently published in the prestigious journal Physics Letters B.

For centuries, scientists have used symmetry as a foundation to understand the universe. The new research findings on symmetry now add to the growing body of scientific knowledge that powers breakthroughs in energy, technology, medicine and beyond.

Conducted at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, the research reveals that quarks—the tiny building blocks of matter—occasionally defy expectations. When hit by high-energy electrons, they sometimes separate and recombine unevenly, challenging long-held ideas about symmetry in nuclear physics.

The research team’s high-precision measurements challenge the status-quo and offer new insight into the strong force that binds subatomic particles. These findings may impact how future experiments interpret quark behavior and the structure of matter.

“The assumptions we make based on symmetries greatly simplify our analyses,” said Dutta, a faculty member in the MSU Department of Physics and Astronomy. “But they haven’t been tested quantitatively with precision until now. Our new results show when the symmetries are valid and when they need certain corrections.”

By uncovering symmetry violations, Dutta and his collaborators are helping refine the theoretical tools physicists use to study subatomic behavior. Their work also lays the groundwork for future studies into other, more subtle symmetries, potentially revealing more about the inner workings of protons and neutrons—the particles that form the core of every atom.

MSU graduate student Hem Bhatt also contributed to the experiment and data analysis as part of his Ph.D. thesis. He was joined on the research team by doctoral students Deepak Bhetuwal and Abishek Karki, who have since completed their degrees, as well as post-doctoral researchers Latiful Kabir, now a staff scientist at Brookhaven National Lab in New York, and Carlos Ayerbe Gayoso, currently a research scientist at Old Dominion University in Virginia. Nuclear physicists from 25 institutions around the world participated in the significant international collaboration.

Physics Letters B is a leading peer-reviewed journal that has published significant advances in nuclear and particle physics since 1967. Known for its rigorous standards and rapid dissemination of research, the journal is widely respected in the global physics community.

 For more details about MSU’s College of Arts and Sciences and Department of Physics and Astronomy, visit www.cas.msstate.edu and www.physics.msstate.edu.

Mississippi State University is taking care of what matters. Learn more at www.msstate.edu.

---

Journal

Physics Letters B

DOI

10.1016/j.physletb.2025.139485 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Flavor dependence of charged pion fragmentation functions

 

UPF and the Royal Veterinary College make the first 3D reconstructions of cat hearts to compare them with humans’

Shortly, 3D reconstructions of the hearts of dogs, pigs and sheep will be made, in addition to simulating their blood flow.

Universitat Pompeu Fabra - Barcelona

Facebook

XLinkedIn

Email

Pompeu Fabra University (UPF) and the Royal Veterinary College of London have worked together on a pioneering project worldwide to generate 3D reconstructions of the hearts of different animals and simulations of their blood flow using advanced computational techniques to date only applied to humans. So far, 3D images of cats’ hearts have been generated, but soon the same will be done for dogs, pigs and sheep.

The project focuses on reconstructing the animals’ left atrium, the part of the heart where thrombi (or blood clots) that can lead to a heart attack occur. By studying these reconstructions and comparing them with the existing ones of the human heart, it is hoped useful conclusions may be drawn to prevent thrombi both in humans and in animals.

Computational tools will enable studying the heart of different species and reduce direct experiments on animals

Moreover, as 3D reconstructions of the left atria of the different species become available, “it will be possible to study this part of the heart using computational methods and reduce the need to experiment directly on animals” – explains Andy L. Olivares (UPF), one of the researchers involved in the project.

The first study resulting from this project, dedicated to the left atrium of cats, has been published recently in Scientific Reports (Nature). The research team is mainly made up of researchers from the Physense group of the BCN MedTech  Research Unit of the UPF Department of Engineering and the Cardiology Service of the Royal Veterinary College in London. Óscar Cámara (Physense, UPF) and Virginia Luis Fuentes (Cardiology Service of the Royal Veterinary College) are the principal co-investigators. Other co-authors of the study are linked to the Sant Joan de Déu Research Institute (IRSJD), Great Ormond Street Hospital for Children (NHS Foundation Trust) in London, and the Institute of Cardiovascular Science at University College London.

Why start studying cats’ hearts?

Cats’ heart tissue has particularly interesting characteristics to ascertain the relationship between heart morphology and thrombi, which, to date, has scarcely been analysed in medicine. In the case of the human heart, most of the existing studies focus on the relationship between clots and the most common type of arrhythmia, atrial fibrillation. The alterations of the movements of the heart muscle caused by arrhythmias cause the blood to be retained in a specific area of the left atrium of the heart where it should not accumulate, the left atrial appendage, which increases the risk of a thrombus.

Conversely, there are still some unknown factors concerning the relationship between the shape of the human heart and the risk of clotting. Precisely, in the case of cats, clots are due solely to heart morphology and the blood flow within, because they do not suffer arrhythmias. Therefore, with felines, the relationship can be analysed between thrombi and heart morphology without interference from arrhythmias. In other words, the first two factors can be isolated from the third.

This study examined the morphology of the left atrium and the blood flow characteristics (or haemodynamics) of 24 cats, 8 healthy (control group) and 16 with different cardiac pathologies. From medical images of the cats’ hearts provided by veterinary clinics, 3D reconstructions of their left atria were generated using advanced computational techniques.

The larger the left atrium of the heart, the greater the risk of blood clots, a pattern shared by cats and humans

The recently published study associates some morphological features of cats’ hearts with some pathologies. 3D heart reconstruction has shown that felines with a larger left atrium and a larger and bigger left atrial appendage are more at risk of clotting. The risk of thrombi is also increased if the blood circulates more slowly inside or if the left atrial appendage is more curved, which forces the blood to zigzag more in order to circulate. The left atrial appendage also has trabeculae (or lobes) and, if numerous, they can also stop blood flow and lead to the formation of clots.

The results suggest that the heart of felines behaves in a similar way to that of humans, since previous studies on the human left atrium had reached similar conclusions. However, more studies will need to be conducted with more feline samples to examine their heart behaviour in more detail.

New tools to prevent thrombi in people and animals

The same research team also plans to examine the left atrium of dogs, pigs and sheep in the near future. In short, they propose carrying out a cross-sectional study of different species to determine which hearts are most similar to the human heart and to provide new tools for diagnosing and preventing thrombi in the medical and veterinary fields.

Reference article:

Pons, MI, Olivares, AL, Mill, J. et al. Cardiomyopathy and thrombogenesis in cats through left atrial morphological and fluid dynamics analysis. Sci Rep 15, 12263 (2025). https://doi.org/10.1038/s41598-025-96245-7

---

Journal

Scientific Reports

DOI

10.1038/s41598-025-96245-7 

Method of Research

Computational simulation/modeling

Subject of Research

Animals

Article Title

Cardiomyopathy and thrombogenesis in cats through left atrial morphological and fluid dynamics analysis

Article Publication Date

10-Apr-2025