Sunday, July 24, 2022

Cardiac rehab attendance lower among Asian, Black and Hispanic adults at all income levels

Journal of the American Heart Association Report

Peer-Reviewed Publication

AMERICAN HEART ASSOCIATION

DALLAS,  — Participation in cardiac rehabilitation is low among Asian, Black and Hispanic adults compared to white adults, with significant disparities by race/ethnicity regardless of income, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

Cardiac rehabilitation programs combine physical activity with counseling about healthy living and stress reduction to help improve recovery after a major cardiovascular event, such as a heart attack, heart failure, heart surgery or angioplasty. Cardiac rehabilitation is proven to be an effective method to for reducing recurrent cardiac events among people who have had a heart attack, heart failure, heart surgery or coronary intervention including angioplasty. A previous meta-analysis found that cardiac rehabilitation decreases the chances of death following a heart attack, or bypass surgery by about 25% and hospital re‐admissions by 18%.

In this study, researchers reviewed health insurance claims data for more than 107,000 people across the U.S. who had diagnoses and/or procedures designated for cardiac rehabilitation. The data came from Optum Clinformatics Data Mart, an administrative database including inpatient, outpatient, emergency department, pharmacy and lab health claims for people with commercial health insurance and Medicare Advantage (C and D). The average age of the people who met the criteria was 70 years; 37% were women; and 76% were white adults, while 2.5% were Asian race, 9.8% were Hispanic ethnicity, and 11.8% were Black race. Each person had experienced one or more of the following cardiovascular events between 2016 and 2018: a heart attack, bypass surgery, heart valve repair or replacement surgery, or angioplasty. Annual household income was estimated and validated from surveys of U.S. households using a comprehensive set of variables that encompass ZIP code data, Internal Revenue Service data, address-level home value, accumulated credit and short-term loans. Among all participants, 34.2% had a high school diploma or lower education level, and 31.5% had an annual household income of less than $40,000. Black individuals were most likely to have a history of high blood pressure, ischemic stroke or other chronic health conditions.

The study evaluated racial and ethnic differences in cardiac rehabilitation participation to determine if household income may affect attendance in cardiac rehabilitation programs.

Researchers found:

  • Overall, only about 26% of all study participants attended one or more cardiac rehabilitation sessions, which included 29.6% of the white individuals, 22.5% of the Asian individuals, 17.6% of the Black individuals and 14.4% of the Hispanic individuals.
  • After adjusting for age, sex, hypertension, diabetes, depression, ischemic stroke, income and education, the probability of attending cardiac rehabilitation was 31% lower among Asian individuals, 19% lower for Black individuals and 43% lower for Hispanic individuals compared to White individuals.
  • Compared to white individuals, the time to attendance in the first cardiac rehabilitation session averaged 9 days longer for Asian and Black people and 10 days longer for Hispanic people.
  • Asian, Black and Hispanic individuals were overall less likely to attend cardiac rehabilitation at all income levels compared to white adults: ranging from 53% less likely among Hispanic people with an annual household income of $60K – $75K; to 13% less likely among Black people earning more than $100K annually.

“Disparities in cardiac rehabilitation participation have been well-documented; however, it is alarming to see the magnitude of the disparities that persist,” said Joshua H. Garfein, M.P.H., co-lead study author and a medical student at the University of Pittsburgh. “We were surprised to find that the racial or ethnic disparities did not decrease at higher income levels, which means we need to do more research to identify the barriers.”

New initiatives are urgently needed to optimize the secondary prevention benefits of cardiac rehabilitation and promote equitable cardiovascular outcomes, researchers said.

“Clinicians should promote cardiac rehabilitation for all eligible patients after a major cardiac event or diagnosis and be aware of the factors that may make it more challenging for some people to participate,” said senior study author Jared W. Magnani, M.D., M.Sc., an associate professor of cardiology at the University of Pittsburgh’s Center for Research on Health Care.

“Future studies should evaluate how other social variables—such as the ability to understand health information, the number of people in a household or employment status—may contribute to disparities in cardiac rehabilitation participation,” Magnani said. “In addition, addressing these disparities will require continued research into new initiatives that may help to increase participation in cardiac rehabilitation programs. Several options include automatic referral, virtual delivery options, development of rehabilitation facilities in underserved or rural areas, community-based cardiac rehabilitation, evening programs and home-based programs.”

The study had several limitations. Race or ethnicity was detailed in the health insurance claims data, and income and education levels were determined by ZIP code and geographic indicators. Additionally, the insurance data examined is for reimbursement purposes, therefore, diagnostic information may have been incomplete. Participants with less than 90 days of insurance enrollment were omitted from the analysis, as well as individuals with missing information, therefore, selection bias may have occurred. The researchers also note that the study only included insured individuals, therefore, the results may underestimate the correlation between low income and cardiac rehabilitation participation.

The American Heart Association supports congressional legislation such as the bipartisan “Increasing Access to Quality Cardiac Rehabilitation Care Act”’ that would expand cardiac rehabilitation resources.

”Studies show that participation in cardiac rehabilitation and prompt initiation of cardiac rehabilitation after hospitalization improve patient outcomes,” said Randal J. Thomas, M.D., a past chair of the American Heart Association's Council on Clinical Cardiology and a professor of medicine in the Mayo Clinic Alix School of Medicine who works with the Mayo Clinic Cardiac Rehabilitation Program in Rochester, Minnesota. “The proposed legislation would be one more tool available to improve referral to and participation in cardiac rehabilitation services by accelerating the timetable for enabling physician assistants, nurse practitioners and clinical nurse specialists to order and supervise cardiac rehabilitation.”

Other co-authors are co-lead author Emily N. Guhl, M.D., M.S.; Gretchen Swabe, M.S.; Akira Sekikawa, M.D., Ph.D.; Emma Barinas-Mitchell, Ph.D.; and Daniel E. Forman, M.D. Authors’ disclosures are listed in the manuscript.

Funding for the study was provided by the National Institutes of Health.

Studies published in the American Heart Association’s scientific journals are peer-reviewed. The statements and conclusions in each manuscript are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are available here. 

Additional Resources:

About the American Heart Association

The American Heart Association is a relentless force for a world of longer, healthier lives. We are dedicated to ensuring equitable health in all communities. Through collaboration with numerous organizations, and powered by millions of volunteers, we fund innovative research, advocate for the public’s health and share lifesaving resources. The Dallas-based organization has been a leading source of health information for nearly a century. Connect with us on heart.org, Facebook, Twitter or by calling 1-800-AHA-USA1.

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JOURNAL

Journal of the American Heart Association

DOI

10.1161/JAHA.122.025591 

ARTICLE TITLE

Cardiac rehab attendance lower among Asian, Black and Hispanic adults at all income levels

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Saturday, July 23, 2022

A simple tool to protect websites from cyber hacking

Reports and Proceedings

UNIVERSITY OF SOUTH AUSTRALIA

An international team of researchers has developed a scanning tool to make websites less vulnerable to hacking and cyberattacks.

The black box security assessment prototype, tested by engineers in Australia, Pakistan and the UAE, is more effective than existing web scanners which collectively fail to detect the top 10 weaknesses in web applications.

UniSA mechanical and systems engineer Dr Yousef Amer is one of the co-authors of a new international paper that describes the development of the tool in the wake of escalating global cyberattacks.

Cybercrime cost the world $6 trillion in 2021, reflecting a 300 per cent hike in online criminal activity in the past two years.

Remote working, cloud-based platforms, malware and phishing scams have led to skyrocketing data breaches, while the rollout of 5G and Internet of Things (IoT) devices has made us more connected – and vulnerable – than ever.

Dr Yousef Amer and colleagues from Pakistan, the UAE and Western Sydney University, highlight numerous security weaknesses in website applications and how these are costing organisations dearly.

Due to the widespread adoption of eCommerce, iBanking and eGovernment sites, web applications have become a prime target of cybercriminals who want to steal individual and company information and disrupt business activities.

Despite a projected $170 billion global outlay on internet security in 2022 against a backdrop of escalating and more severe cyberattacks, existing web scanners are falling way short when it comes to assessing  vulnerabilities, according to Dr Amer.

“We have identified that most of the publicly available scanners have weaknesses and are not doing the job they should,” he says.

Nearly 72 per cent of organisations have suffered at least one serious security breach on their website, with vulnerabilities tripling since 2017.

WhiteHat Security, a world leader in web application security, estimates that 86 per cent of scanned web pages have on average 56 per cent vulnerabilities. Among these, at least one is classified as critical.

The researchers compared 11 publicly available web application scanners against the top 10 vulnerabilities.

“We found that no single scanner is capable of countering all these vulnerabilities, but our prototype tool caters for all these challenges. It’s basically a one-stop guide to ensure 100 per cent website security,” Dr Amer says.

“There’s a dire need to audit websites and ensure they are secure if we are to curb these breaches and save companies and governments millions of dollars.”

The researchers are now seeking to commercialise their prototype.

DOI

10.1109/ICAI55435.2022.9773750 

METHOD OF RESEARCH

Computational simulation/modeling

ARTICLE TITLE

SAT: Integrated Multi-agent Blackbox Security Assessment Tool using Machine Learning

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Organ storage a step closer with cryopreservation discovery

Peer-Reviewed Publication

RMIT UNIVERSITY

Australian scientists have taken the first step towards improved storage of human cells, which may lead to the safe storage of organs such as hearts and lungs. 

The team’s discovery of new cryoprotective agents opens the door to many more being developed that could one day help to eliminate the need for organ transplant waiting lists. Their results are published in the Journal of Materials Chemistry B.

Cryopreservation is a process of cooling biological specimens down to very low temperatures so they can be stored for a long time. Storing cells through cryopreservation has had big benefits for the world – including boosting supplies at blood banks and assisting reproduction – but it is currently impossible to store organs and simple tissues.  

The lead researcher, Dr Saffron Bryant from RMIT University, said that in the United States around 60% of all donated hearts and lungs were discarded. 

While figures vary in other countries, preservation and transport times remain a global issue.

“We have these massive organ shortages, and we only have hours to get an organ from a donor to a recipient,” Bryant said. 

About 1,850 people are on the waiting list for an organ transplant in Australia, while more than 100,000 Americans are waiting for a transplant.  

Bryant said transplant waiting lists could become a problem of the past, as the RMIT team’s discovery of new cryoprotective agents could lead to the development of potentially thousands more that could help keep donated organs viable for years, rather than hours. 

“For the past 50 years cryopreservation practices have largely relied on the same two cryoprotective agents, but they don't work for organs and many cell types,” she said. 

Cryoprotective agents are like the antifreeze that you put in your car to stop the engine freezing as they allow the storage of cells at very low temperatures, Bryant said.  

“These agents help to protect against damage during cryopreservation, primarily from dehydration and freezing by preventing the formation of ice crystals that can damage cells,” she said. 

“Ice crystals cause damage inside cells. Cryoprotectants stop ice forming, leading to a glassy structure instead that can solidify but doesn't cause the same sort of damage as ice crystals.” 

The research team discovered a cryoprotectant with two agents, proline and glycerol, was effective for all four cell types tested, including skin and brain cells, which were incubated with the cryoprotectant at 37 degrees Celsius before being frozen.  

“This cryoprotectant was more effective and less toxic than its individual components,” Bryant said. 

“This is one of the first times that this class of solvents has been systematically tested for cryopreservation of mammalian cells. 

“This study could lead to the development of potentially thousands of new cryoprotective agents that may be tailored to specific cell types.” 

Bryant said incubating these cells with the cryoprotectant at 37 degrees Celsius for several hours prior to freezing and keeping them viable is a crucial step towards the storage of organs and tissues.  

“It means we could expose organs to the cryoprotectants for long enough for them to penetrate into the deepest layers of the organ without causing damage,” she said. 

“We have a long way to go with our research, as we've only looked at single cells and it's a much more complicated process for organs. 

“But if we can develop this approach to store organs, we could eliminate organ shortages – there would be no waiting lists at all.” 

As a next step, the RMIT team will investigate ways to cryopreserve new cell types, including some that cannot be frozen and kept viable using current methods.  

“We're also working with Lifeblood to investigate cryopreservation of blood products such as platelets, which are vital for the treatment of patients who have suffered significant blood loss,” Bryant said.  

“Current technology only enables the storage of platelets for up to a week, but with successful cryopreservation they could be stored for years.” 

‘Deep eutectic solvents as cryoprotective agents for mammalian cells’, with RMIT co-authors Saffron Bryant, Miyah Awad, Aaron Elbourne, Andrew Christofferson, Andrew Martin, Nastaran Meftahi, Calum Drummond, Tamar Greaves and Gary Bryant, is published in the Journal of Materials Chemistry B (DOI: 10.1039/D2TB00573E). 

IMAGES FOR MEDIA USE:

Here is a link to the images, along with captions and credit information: https://cloudstor.aarnet.edu.au/plus/s/WpCeiCrqpVN6mAh 

JOURNAL

Journal of Materials Chemistry B

DOI

10.1039/D2TB00573E 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Deep eutectic solvents as cryoprotective agents for mammalian cells

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LE SURREALISTES WERE RIGHT

Study links obsessive passion and social alienation to support for political violence

Peer-Reviewed Publication

UNIVERSITY OF CÓRDOBA

Stock image of a container burning in the street 

IMAGE: STOCK IMAGE OF A CONTAINER BURNING IN THE STREET view more 

CREDIT: UNIVERSITY OF CÓRDOBA

Violent extremism could be defined as support for violence to achieve political, ideological or social objectives. Under the umbrella of this type of mindset, violent acts are seen as a legitimate means of imposing a way of life in which there is no room for diversity. But what really underlies this type of behavior, and what drives a given person to exhibit these behaviors in which political violence is a desirable option?


A research team at the University of Cordoba (UCO) and the Marbella International University Center asked itself this same question and, in a study published in the Journal of Interpersonal Violence, analyzes some of the factors involved in this radicalization process. According to the main conclusions of the work, there are two elements that may foster extremism and that, therefore, can be considered risk factors: social alienation, and what in the scientific literature is known as "obsessive passion." The more intense these two feelings are, "the greater the support for political violence," the study states.


While social alienation can be understood as a feeling of detachment and disconnection from society, obsessive passion implies a tendency towards a certain activity in which, in a certain way, self-control is lost. "There is harmonious passion, which is positive and spurs us to perform rewarding actions, but also another linked to negative indicators of mental health and psychosocial adjustment," explained researcher Manuel Moyano, one of the researchers in the Department of Psychology at the UCO who participated in the study. It is precisely this latter feeling which, according to the results of the study, makes individuals more likely to respond violently to what they consider attacks on their identity.


To reach this conclusion, the team surveyed more than 1,500 people varying in age, background, education and employment status in two complementary studies. The first one evaluated the concept of religion as a cause of obsessive passion, while a second study, carried out with a different sample, analyzed another of the causes that can turn certain people into "obsessively passionate" beings: family. However, as the study points out, there are many causes that can give free rein to this uncontrolled passion and that should be taken into account in future studies. 


Both studies confirmed the same hypothesis: the feeling of social alienation - that is, of disengagement with society - can trigger extreme behavior and support for political violence, especially in "people who develop an obsessive passion for a particular cause or ideology," the study concludes. 


Understanding how these factors are related, explains Professor Moyano, can be key to better understanding the mechanisms that lead to violent extremism and, above all, to developing new strategies focused on preventing political violence, a high-priority objective in times like today, in which new armed conflicts are reshaping international relations and in which various studies have warned of the increase in social polarization. In this context, understanding the social and psychological causes of the process of violent radicalization is crucial to being able to take proactive prevention and coping actions.  
 

JOURNAL

Journal of Interpersonal Violence

DOI

10.1177/08862605221094631 

METHOD OF RESEARCH

News article

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Disconnected Out of Passion: Relationship Between Social Alienation and Obsessive Passion

Making sense of socially enhanced aggression in the brain


Researchers from the University of Tsukuba identify the brain pathway that is responsible for the "priming" of aggression that occurs when male animals spend time together

Peer-Reviewed Publication

UNIVERSITY OF TSUKUBA

Researchers from the University of Tsukuba identify the brain pathway that is responsible for the "priming" of aggression that occurs when male animals spend time together

Tsukuba, Japan—When male animals spend time around other males of the same species, subsequent aggressive behavior tends to be amplified—this type of priming is known as social instigation. However, the pathway in the brain that leads to this increased aggression was, until recently, relatively unknown. In a study published in Nature Communications, researchers from the University of Tsukuba have revealed that the lateral habenula, a small and relatively primitive region located deep within the brain, is important for this behavior in mice.

Aggressive behavior, especially between males, is important in many animal species and can be promoted in a number of different ways, including by social instigation. Although this behavioral effect is well characterized, the brain pathway that is responsible for it is less understood. The dorsal raphe nucleus is a brain region that controls aggressive behaviors, and it receives glutamate (a molecule that acts as a signal between brain cells) when social instigation occurs. However, the source of this glutamate was a mystery. Researchers from the University of Tsukuba decided to address this gap in the knowledge.

"Many different brain regions release glutamate into the dorsal raphe nucleus," explains lead author of the study Professor Aki Takahashi. "Because our initial experiments suggested that glutamate release from the lateral habenula might be responsible for aggression induced by social instigation, we conducted more experiments to see if this was the case."

The research team used two different techniques to block communication between the lateral habenula and dorsal raphe nucleus in mice, and found that this also blocked the increased aggression caused by social instigation—but it didn't affect normal levels of aggression, suggesting that this pathway is not important for aggressive behavior in general.

"We then wanted to look at the pathway beyond the dorsal nucleus," says Professor Takahashi. "We found that social instigation caused signals to travel through the brain from the lateral habenula to the dorsal raphe nucleus and then on to the ventral tegmental area—a highly connected region in the midbrain—leading to heightened aggression."

Although there are many differences in aggression between humans and mice, the results of this new study may have applications when investigating socially provoked anger or violence. There is currently a lack of effective preventative measures against socially provoked aggression, and any information that increases our understanding of these aggressive behaviors will be useful.

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This research was supported by JSPS KAKENHI Grant Numbers JP17H04766, JP19H05202, JP21H00183, Japan Science and Technology Agency (JST) Adaptable and Seamless Technology transfer Program through Target-driven R&D (A-STEP) Grant Number JPMJTM20BW and JST FOREST Program Grant Number JPMJFR214A to AT, and by National Institute of Mental Health grants R01MH114882-01, R01MH104559, and R01MH127820 to SJR.
 

Original Paper

The article, "Lateral habenula glutamatergic neurons projecting to the dorsal raphe nucleus promote aggressive arousal in mice," was published in Nature Communications at DOI: 10.1038/s41467-022-31728-z

Correspondence

Associate Professor TAKAHASHI Aki
Faculty of Human Sciences

Related Link

Faculty of Human Sciences

 

JOURNAL

Nature Communications

DOI

10.1038/s41467-022-31728-z 

ARTICLE TITLE

Lateral habenula glutamatergic neurons projecting to the dorsal raphe nucleus promote aggressive arousal in mice

ARTICLE PUBLICATION DATE

21-Jul-2022

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Tiny fish-shaped robot ‘swims’ around picking up microplastics

Peer-Reviewed Publication

AMERICAN CHEMICAL SOCIETY

Tiny fish-shaped robot ‘swims’ around picking up microplastics 

IMAGE: A LIGHT-ACTIVATED FISH-SHAPED ROBOT COLLECTS MICROPLASTICS AS IT SWIMS (SCALE BAR IS 10 MM). view more 

CREDIT: ADAPTED FROM NANO LETTERS 2022, DOI: 10.1021/ACS.NANOLETT.2C01375

Microplastics are found nearly everywhere on Earth and can be harmful to animals if they’re ingested. But it’s hard to remove such tiny particles from the environment, especially once they settle into nooks and crannies at the bottom of waterways. Now, researchers in ACS’ Nano Letters have created a light-activated fish robot that “swims” around quickly, picking up and removing microplastics from the environment.

Because microplastics can fall into cracks and crevices, they’ve been hard to remove from aquatic environments. One solution that’s been proposed is using small, flexible and self-propelled robots to reach these pollutants and clean them up. But the traditional materials used for soft robots are hydrogels and elastomers, and they can be damaged easily in aquatic environments. Another material called mother-of-pearl, also known as nacre, is strong and flexible, and is found on the inside surface of clam shells. Nacre layers have a microscopic gradient, going from one side with lots of calcium carbonate mineral-polymer composites to the other side with mostly a silk protein filler. Inspired by this natural substance, Xinxing Zhang and colleagues wanted to try a similar type of gradient structure to create a durable and bendable material for soft robots.

The researchers linked Î²-cyclodextrin molecules to sulfonated graphene, creating composite nanosheets. Then solutions of the nanosheets were incorporated with different concentrations into polyurethane latex mixtures. A layer-by-layer assembly method created an ordered concentration gradient of the nanocomposites through the material from which the team formed a tiny fish robot that was 15-mm (about half-an-inch) long. Rapidly turning a near-infrared light laser on and off at a fish’s tail caused it to flap, propelling the robot forward. The robot could move 2.67 body lengths per second — a speed that’s faster than previously reported for other soft swimming robots and that is about the same speed as active phytoplankton moving in water. The researchers showed that the swimming fish robot could repeatedly adsorb nearby polystyrene microplastics and transport them elsewhere. The material could also heal itself after being cut, still maintaining its ability to adsorb microplastics. Because of the durability and speed of the fish robot, the researchers say that it could be used for monitoring microplastics and other pollutants in harsh aquatic environments.

The authors acknowledge funding from a National Key Research and Development Program of China Grant, National Natural Science Foundation of China Grants and the Sichuan Provincial Natural Science Fund for Distinguished Young Scholars.

The paper’s abstract will be available on June 22 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.2c01375.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. 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, eBooks 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.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

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JOURNAL

Nano Letters

DOI

10.1021/acs.nanolett.2c01375 

ARTICLE TITLE

Robust, Healable, Self-Locomotive Integrated Robots Enabled by Noncovalent Assembled Gradient Nanostructure


Silk offers an alternative to some microplastics


Researchers have developed a biodegradable system based on silk to replace microplastics added to agricultural products, paints, and cosmetics

Peer-Reviewed Publication

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Replacing microplastics 

IMAGE: THESE SCANNING ELECTRON MICROSCOPE IMAGES SHOW SILK-COATED MICROCAPSULES CONTAINING VITAMIN C, AT DIFFERENT SCALES OF DETAIL. ON THE LEFT, AND TOP CENTER, SAMPLES MADE BY SPRAY DRYING, A METHOD ALREADY WIDELY USED IN INDUSTRY. ON THE RIGHT AND AT BOTTOM CENTER, SAMPLES MADE BY ULTRASONIC SPRAY FREEZE DRYING, A METHOD USED BY THE RESEARCHERS TO REVEAL GREATER DETAIL OF THE PROCESS INVOLVED. view more 

CREDIT: CREDITS:SEM IMAGES BY MUCHUN LIU, EDITED BY MIT NEWS

Microplastics, tiny particles of plastic that are now found worldwide in the air, water, and soil, are increasingly recognized as a serious pollution threat, and have been found in the bloodstream of animals and people around the world.

Some of these microplastics are intentionally added to a variety of products, including agricultural chemicals, paints, cosmetics, and detergents — amounting to an estimated 50,000 tons a year in the European Union alone, according to the European Chemicals Agency. The EU has already declared that these added, nonbiodegradable microplastics must be eliminated by 2025, so the search is on for suitable replacements, which do not currently exist.

Now, a team of scientists at MIT and elsewhere has developed a system based on silk that could provide an inexpensive and easily manufactured substitute. The new process is described in a paper in the journal Small, written by MIT postdoc Muchun Liu, MIT professor of civil and environmental engineering Benedetto Marelli, and five others at the chemical company BASF in Germany and the U.S.

The microplastics widely used in industrial products generally protect some specific active ingredient (or ingredients) from being degraded by exposure to air or moisture, until the time they are needed. They provide a slow release of the active ingredient for a targeted period of time and minimize adverse effects to its surroundings. For example, vitamins are often delivered in the form of microcapsules packed into a pill or capsule, and pesticides and herbicides are similarly enveloped. But the materials used today for such microencapsulation are plastics that persist in the environment for a long time. Until now, there has been no practical, economical substitute available that would biodegrade naturally.

Much of the burden of environmental microplastics comes from other sources, such as the degradation over time of larger plastic objects such as bottles and packaging, and from the wear of car tires. Each of these sources may require its own kind of solutions for reducing its spread, Marelli says. The European Chemical Agency has estimated that the intentionally added microplastics represent approximately 10-15 percent of the total amount in the environment, but this source may be relatively easy to address using this nature-based biodegradable replacement, he says.

“We cannot solve the whole microplastics problem with one solution that fits them all,” he says. “Ten percent of a big number is still a big number. … We’ll solve climate change and pollution of the world one percent at a time.”

Unlike the high-quality silk threads used for fine fabrics, the silk protein used in the new alternative material is widely available and less expensive, Liu says. While silkworm cocoons must be painstakingly unwound to produce the fine threads needed for fabric, for this use, non-textile-quality cocoons can be used, and the silk fibers can simply be dissolved using a scalable water-based process. The processing is so simple and tunable that the resulting material can be adapted to work on existing manufacturing equipment, potentially providing a simple “drop in” solution using existing factories.

Silk is recognized as safe for food or medical use, as it is nontoxic and degrades naturally in the body. In lab tests, the researchers demonstrated that the silk-based coating material could be used in existing, standard spray-based manufacturing equipment to make a standard water-soluble microencapsulated herbicide product, which was then tested in a greenhouse on a corn crop. The test showed it worked even better than an existing commercial product, inflicting less damage to the plants, Liu says.

While other groups have proposed degradable encapsulation materials that may work at a small laboratory scale, Marelli says, “there is a strong need to achieve encapsulation of high-content actives to open the door to commercial use. The only way to have an impact is where we can not only replace a synthetic polymer with a biodegradable counterpart, but also achieve performance that is the same, if not better.”

The secret to making the material compatible with existing equipment, Liu explains, is in the tunability of the silk material. By precisely adjusting the polymer chain arrangements of silk materials and addition of a surfactant, it is possible to fine-tune the properties of the resulting coatings once they dry out and harden. The material can be hydrophobic (water-repelling) even though it is made and processed in a water solution, or it can be hydrophilic (water-attracting), or anywhere in between, and for a given application it can be made to match the characteristics of the material it is being used to replace.

In order to arrive at a practical solution, Liu had to develop a way of freezing the forming droplets of encapsulated materials as they were forming, to study the formation process in detail. She did this using a special spray-freezing system, and was able to observe exactly how the encapsulation works in order to control it better. Some of the encapsulated “payload” materials, whether they be pesticides or nutrients or enzymes, are water-soluble and some are not, and they interact in different ways with the coating material.

“To encapsulate different materials, we have to study how the polymer chains interact and whether they are compatible with different active materials in suspension,” she says. The payload material and the coating material are mixed together in a solution and then sprayed. As droplets form, the payload tends to be embedded in a shell of the coating material, whether that’s the original synthetic plastic or the new silk material.

The new method can make use of low-grade silk that is unusable for fabrics, and large quantities of which are currently discarded because they have no significant uses, Liu says. It can also use used, discarded silk fabric, diverting that material from being disposed of in landfills.

Currently, 90 percent of the world’s silk production takes place in China, Marelli says, but that’s largely because China has perfected the production of the high-quality silk threads needed for fabrics. But because this process uses bulk silk and has no need for that level of quality, production could easily be ramped up in other parts of the world to meet local demand if this process becomes widely used, he says.

The research team also included Pierre-Eric Millard, Ophelie Zeyons, Henning Urch, Douglas Findley and Rupert Konradi from the BASF corporation, in Germany and in the U.S. The work was supported by BASF through the Northeast Research Alliance (NORA).

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Written by David L. Chandler, MIT News Office

Additional background

Paper: “Microencapsulation of high-content actives using biodegradable silk materials.”

https://onlinelibrary.wiley.com/doi/full/10.1002/smll.202201487

DOI

10.1002/smll.202201487 

ARTICLE TITLE

“Microencapsulation of high-content actives using biodegradable silk materials.”

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Long sought-after particle consisting of four neutrons discovered 

OR CREATED BY THE OBSERVERS

Research team for the first time observed a neutral nucleus: the Tetra Neutron

IT MIGHT ALL BE IN THEIR IMAGINATIONS

Peer-Reviewed Publication

TECHNISCHE UNIVERSITAT DARMSTADT

The experiment has been carried out at the Radioactive Ion Beam Factory RIBF at RIKEN (Japan) by a large international research team. Significantly involved were besides TU Darmstadt, scientists from TU Munich, the RIKEN Nishina Center, and the GSI Helmholtz Center for Heavy-ion Research. The experiment yielded an unambiguous signal for the first observation of the Tetra Neutron. The result has been published in the current issue of “Nature”.

The building blocks of atomic nuclei are nucleons, which exist as two kinds, the neutral neutrons and the charged protons, representing the two isospin states of the nucleon. To our present knowledge, nuclei made of neutrons only are not existing as bound nuclei. The only bound systems known made of almost only neutrons are neutron stars, which are very compact high-density objects in the universe bound by the gravitational force with typical diameters of around 10 kilometers. Atomic nuclei are bound by the nuclear strong force with a preference to balance neutrons and protons, as known for the stable nuclei we find on earth.

The study of pure neutron systems is of particular importance since they provide the only means to extract experimental information on the interaction among several neutrons and thereby on the nuclear force. If multi-neutron systems do exist as resonances or even bound states has been a long-standing quest in nuclear physics. The exploration of the so far hypothetical particles might furthermore provide information helping for a better understanding of neutron-star properties. If multi-neutron systems do exist as unbound resonant states or even bound states has been a long-standing quest in nuclear physics. A research team lead by scientists from TU Darmstadt set out to undertake a new attempt by using a different experimental technique as compared to previous attempts. This work was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) via the SFB 1245.

“This experimental break-through provides a benchmark to test the nuclear force with a pure system made of neutrons only", says Dr. Meytal Duer from Institute for Nuclear Physics at the TU Darmstadt. “The nuclear interaction among more than two neutrons could not be tested so far, and theoretical predictions yield a wide scatter concerning the energy and width of a possible tetra neutron state. We are currently planning to a next-generation experiment at R3B at FAIR, which will detect directly the correlations among the four neutrons with the R3B NeuLAND detector, which will give deeper insight to the nature of this four-neutron system”.

The experimental study of pure neutron systems is challenging because neutron targets do not exist. In order to create multi-neutron systems in a volume where the neutrons can interact via the short-range nuclear force (few femto-meter, 10-15 meter), nuclear reactions have to be used. Here, the interaction of the neutrons with other particles involved in the reaction process poses a major problem, which can mask the properties of the pure neutron interaction. The scientists have overcome this problem by shooting out the compact alpha core from 8He instantaneously induced by a proton of the liquid hydrogen target. The remaining four neutrons are suddenly free and left alone and can interact among each other.

“Key for the successful observation of the Tetra Neutron was the chosen reaction, which isolates the four neutrons in a fast (compared to the nuclear scale) process, and the chosen kinematics of large momentum-transfer, which separates the neutrons from the charged particles in momentum space”, says Professor Dr. Thomas Aumann from the Institute for Nuclear Physics at TU Darmstadt. “The extreme kinematics resulted in an almost background-free measurement. We now plan to employ the same reaction in an experiment at the RIBF to make a precision measurement of the low-energy neutron-neutron interaction. A dedicated neutron detector for this experiment is currently being built at our university”.

 

The Publication

M. Duer, T. Aumann et al.: „Observation of a correlated free four-neutron system“, in „Nature“ (2022), June 22nd 2022, DOI: 10.1038/s41586-022-04827-6, https://go.nature.com/3n8mBvu

 

About TU Darmstadt

TU Darmstadt is one of Germany’s leading technical universities and a synonym for excellent, relevant research. We are crucially shaping global transformations – from the energy transition via Industry 4.0 to artificial intelligence – with outstanding insights and forward-looking study opportunities. TU Darmstadt pools its cutting-edge research in three fields: Energy and Environment, Information and Intelligence, Matter and Materials. Our problem-based interdisciplinarity as well as our productive interaction with society, business and politics generate progress towards sustainable development worldwide. Since we were founded in 1877, we have been one of Germany’s most international universities; as a European technical university, we are developing a trans-European campus in the network, Unite! With our partners in the alliance of Rhine-Main universities – Goethe University Frankfurt and Johannes Gutenberg University Mainz – we further the development of the metropolitan region Frankfurt-Rhine-Main as a globally attractive science location.

www.tu-darmstadt.de

MI-Nr. 39/2022, Aumann/mih

JOURNAL

Nature

DOI

10.1038/s41586-022-04827-6 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

„Observation of a correlated free four-neutron system“

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