IF EATEN DAILY

Study: How red meat's digested may help explain heart risks

By Judy Packer-Tursman

New research suggests gut microbes may cause part of the higher risk of cardiovascular disease from eating red meat. 

Photo by Engin_Akyurt/Pixabay

WASHINGTON, Aug. 1 (UPI) -- New research suggests chemicals produced in the digestive tract by gut microbes may help explain the higher risk of cardiovascular disease from a diet of steak and hamburgers.

This flies in the face of most scientific studies on the harmful effects of red meat on heart health, which have focused on dietary saturated fat and blood cholesterol levels.

The study was published Monday in Arteriosclerosis, Thrombosis, and Vascular Biology, the American Heart Association's peer-reviewed journal.

Heart disease is the leading cause of death in the United States. Nationwide, nearly 700,000 people died from it in 2020, accounting for 1 in every 5 deaths, the Centers for Disease Control and Prevention says.

The risk of developing cardiovascular disease, including heart attack and stroke, increases with age. But experts say heart health may be improved by lifestyle factors such as regular exercise, good sleep, healthy body weight -- and eating healthy foods.

Meng Wang, the study's co-lead author, told UPI in an email that the new evidence reinforces longstanding American Heart Association recommendations that Americans should limit their intake of red meat and processed meat to reduce heart disease risk.

According to Wang, a postdoctoral fellow at Tufts University's Friedman School of Nutrition Science and Policy in Boston, the new research "helps us better understand why meat intake [is] associated with a higher cardiovascular risk."

Previous research has found that certain metabolites -- chemical byproducts of food digestion -- are associated with a greater risk of cardiovascular disease, a news release said.

One such metabolite is TMAO, or trimethylamine N-oxide, which is produced by gut bacteria to digest red meat and contains high amounts of the chemical L-carnitine .

However, the extent to which TMAO and related metabolites derived from L-carnitine may contribute to cardiovascular risk associated with red meat consumption is unclear.

So, the researchers measured levels of the metabolites in blood samples, and also examined whether blood sugar, inflammation, blood pressure and blood cholesterol may account for elevated cardiovascular risk associated with red meat consumption.

According to Wang, "The novel set of metabolites generated by our gut microbes, as well as pathways related to blood sugar and general inflammation, appeared to explain much of this elevated risk -- more so than blood cholesterol or blood pressure."

These findings suggest that when making dietary recommendations, "it may be less important to focus on saturated fat or cholesterol content in red meat," Wang said. "Other components like L-carnitine and heme iron in red meat may play a more important role and need to be better studied."

Wang said in a press release that, based on the study's findings, "novel interventions may be helpful to target the interactions between red meat and the gut microbiome to help us find ways to reduce cardiovascular risk."

One example of "novel interventions," she explained to UPI, is "medications to inhibit the generation of TMAO-related metabolites. It could potentially be used in people with high TMAO levels."

Could this result in a person taking a pill along with their steak in the future?

Said Wang, "Theoretically what you described is possible. However, I would say that following healthy eating behaviors is still an important first step to reduce cardiovascular risk, since it is safer and likely also more cost-effective compared to medications and can be applied to everyone."

She added: "Medications are usually used when lifestyle modifications alone cannot successfully manage the risk."

Study participants included nearly 4,000 of 5,888 adults initially recruited more than three decades ago for the Cardiovascular Health Study: federally funded research looking at risk factors for cardiovascular disease in adults aged 65 or older.

Participants' average age was 73, nearly two-thirds were female, and 88% self-identified as white.

Over the course of the study, participants provided blood samples and answered questionnaires about their dietary habits.

For the new study, the researchers compared the risk of cardiovascular disease among participants who ate different amounts of animal source foods, including red meat, processed meat, fish, chicken and eggs.

They found that eating more meat, especially red meat and processed meat, was linked to a higher risk of atherosclerotic cardiovascular disease: a 22% higher risk for about every 1.1 servings per day, the release said.

The scientists said the increase in TMAO and related metabolites found in the blood explained roughly one-tenth of this elevated risk.

They also noted that blood sugar and inflammation appear to be more important in linking red meat intake and cardiovascular disease than pathways related to blood cholesterol or blood pressure.

And the researchers concluded that eating fish, poultry and eggs was not significantly linked to higher risk of cardiovascular disease.

Wang noted the significance of having older adults participate in the study, though the findings may not apply to populations that are younger or more racially diverse.

She said "there haven't been many studies of animal source food intake and cardiovascular disease specifically focusing on this age group. So our study provides an important piece of evidence for older adults."

Christopher Gardner, chair of the American Heart Association's Nutrition Committee, told UPI in an email these findings "won't change anything for the vegan or vegetarian, other than further reinforcing their convictions and practices."

Gardner, professor of medicine at Stanford University and director of nutrition studies at the Stanford Prevention Research Center, said he will assume "the committed carnivore will brush this off as sounding too complex to move them to make a change."

However, the nutrition scientist said he thinks the target audience for this new finding is "the many people" who are considering eating less red meat.

"Maybe this is the added finding that convinces the on-the-fence flexitarian that despite some of the misinformation campaigns and social media confusion created around saturated fat, cholesterol, and fiber ... there is yet another scientifically plausible explanation for harm to health from red meat, published in a peer-reviewed, high-impact medical journal," Gardner said.

Research links red meat intake, gut microbiome, and cardiovascular disease in older adults

Microbiome-related metabolites like TMAO, as well as blood sugar and general inflammation, appear more important than blood cholesterol or blood pressure in mediating heart disease risk

Peer-Reviewed Publication

TUFTS UNIVERSITY

Does eating more meat—especially red meat and processed meat—raise the risk of cardiovascular disease, and if so, why? Despite intense study, the impact of animal source foods on atherosclerotic cardiovascular disease (ASCVD) is vigorously debated, and the mechanisms underlying potential effects of animal proteins remain unclear. Understanding the impacts of meat consumption is particularly important in older adults, because they are the most vulnerable to heart disease yet may benefit from intake of protein to offset age-related loss of muscle mass and strength. 

Over the years, scientists have investigated the relationship between heart disease and saturated fat, dietary cholesterol, sodium, nitrites, and even high-temperature cooking, but evidence supporting many of these mechanisms has not been robust. Recent evidence suggests that the underlying culprits may include specialized metabolites created by our gut bacteria when we eat meat. 

A new study led by researchers at the Friedman School of Nutrition Science and Policy at Tufts University and Cleveland Clinic Lerner Research Institute quantifies the risk of ASCVD associated with meat intake and identifies underlying biologic pathways that may help explain this risk. The study of almost 4,000 U.S. men and women over age 65 shows that higher meat consumption is linked to higher risk of ASCVD—22 percent higher risk for about every 1.1 serving per day—and that about 10 percent of this elevated risk is explained by increased levels of three metabolites produced by gut bacteria from nutrients abundant in meat. Higher risk and interlinkages with gut bacterial metabolites were found for red meat but not poultry, eggs, or fish. 

The study, published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology (ATVB) on August 1, is the first to investigate the interrelationships between animal source foods and risk of ASCVD events, and the mediation of this risk by gut microbiota-generated compounds as well as by traditional ASCVD risk pathways such as blood cholesterol, blood pressure, and blood sugar. 

The research drew on years of data from the National Institutes of Health’s (NIH’s) Cardiovascular Health Study (CHS), a long-term observational study of risk factors for cardiovascular disease in Americans age 65 and older. Several blood biomarkers were measured at baseline and again during follow-up, including levels of the gut-microbiome generated trimethylamine N-oxide (TMAO) and two of its key intermediates, gamma-butyrobetaine and crotonobetaine, derived from L-carnitine, abundant in red meat. 

Highlights 

• In this community-based cohort of older U.S. men and women, higher intakes of unprocessed red meat, total meat (unprocessed red meat plus processed meat), and total animal source foods were prospectively associated with a higher incidence of ASCVD during a median follow-up of 12.5 years. 
• The positive associations with ASCVD were partly mediated (8-11 percent of excess risk) by plasma levels of TMAO, gamma-butyrobetaine, and crotonobetaine. 
• The higher risk of ASCVD associated with meat intake was also partly mediated by levels of blood glucose and insulin and, for processed meats, by systematic inflammation but not by blood pressure or blood cholesterol levels. 
• Intakes of fish, poultry, and eggs were not significantly associated with ASCVD. 

“These findings help answer long-standing questions on mechanisms linking meats to risk of cardiovascular diseases,” said the paper’s co-first author Meng Wang, a post-doctoral fellow at the Friedman School. “The interactions between red meat, our gut microbiome, and the bioactive metabolites they generate seem to be an important pathway for risk, which creates a new target for possible interventions to reduce heart disease.” 

The 3,931 study subjects were followed for a median of 12.5 years, and their average age at baseline was 73. The study adjusted for established risk factors such as age, sex, race/ethnicity, education, smoking, physical activity, other dietary habits, and many additional risk factors. 

“Interestingly, we identified three major pathways that help explain the links between red and processed meat and cardiovascular disease—microbiome-related metabolites like TMAO, blood glucose levels, and general inflammation—and each of these appeared more important than pathways related to blood cholesterol or blood pressure,” said co-senior author, Dariush Mozaffarian, dean for policy at the Friedman School. “This suggests that, when choosing animal-source foods, it’s less important to focus on differences in total fat, saturated fat, or cholesterol, and more important to better understand the health effects of other components in these foods, like L-carnitine and heme iron.” 

By leveraging extensive clinical and dietary data among a large elderly community, the research “links the gut microbial TMAO pathway to animal source foods and heightened atherosclerotic cardiovascular disease risks,” said co-senior author Stanley L. Hazen, section head of preventive cardiology and rehabilitation at Cleveland Clinic. “The study also argues for dietary efforts as a means of reducing that risk, since dietary interventions can significantly lower TMAO.”

More study is needed to determine if the findings are generalizable across ages and nationalities. The authors also noted that while microbiome biomarkers were directly measured in the blood, the dietary habits of study participants were self-reported, and study findings are observational and cannot prove cause-and-effect. 

Ahmed Hasan, a medical officer and program director in the Atherothrombosis & Coronary Artery Disease Branch at the National Heart, Lung, and Blood Institute, part of the NIH, agrees. “While more studies are needed, the current reports provide a potential new target for preventing or treating heart disease in a subgroup of people who consume excessive amounts of red meat,” said Hasan, who was not a part of the study. 

For now, consumers are encouraged to follow current recommendations for a heart-healthy lifestyle, including adapting a healthy diet that is rich in vegetables, fruits, whole grains, and other heart-healthy foods, NHLBI’s Hasan said. Other heart-healthy lifestyle changes also include aiming for a healthy weight, managing stress, managing blood pressure, getting more exercise, getting adequate sleep, and quitting smoking, he added.

Higher Levels of TMAO, Related Metabolites Linked to Higher Risk of Death

The ATVB study is part of ongoing collaboration among scientists at the Friedman School and Cleveland Clinic to uncover the role that the gut microbiome plays in human health, especially cardiovascular health. In a paper in JAMA Network Open in May, many of the same researchers reported that TMAO and related metabolites in older adults are positively associated with a higher risk of death whether deaths were related to cardiovascular disease or another disease. Participants with the highest levels of plasma TMAO and its biomarkers had a 20 to 30 percent higher risk of death compared with those having the lowest levels. 

This study included more than 5,000 participants from the CHS. Findings were notable because there have been few studies of TMAO and risk of death in the general population; previous research typically looked at clinical patients with underlying conditions such as diabetes, kidney disease, and heart disease. While identified risk factors are concerning, the good news is that TMAO levels are potentially modifiable. “Now that we know more about the severity of risks associated with TMAO, we can explore effective approaches to change these levels in the body,” said the paper’s co-first author, Amanda Fretts of the University of Washington Department of Epidemiology.

Both the ATVB and JAMA Network Open studies support the importance of the microbiome and specific metabolites to human health, with the ATVB paper specifically linking the gut microbiome with meat intake, and impacts on heart health. 

On the ATVB paper, Zeneng Wang of Cleveland Clinic was co-first author. On the JAMA Network Open paper, Hazen was co-first author; Rozenn Lemaitre of the University of Washington and Mozaffarian were co-senior authors. Work was supported by awards from the National Heart, Lung, and Blood Institute of the National Institutes of Health (R01HL135920, R01HL103866, and R01HL130819). Complete information on authors, funders, and conflicts of interest is available in the published papers. 

DISCLAIMER: This content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. 

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JOURNAL

Arteriosclerosis Thrombosis and Vascular Biology

DOI

10.1161/ATVBAHA.121.316533 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Dietary Meat, Trimethylamine N-Oxide-Related Metabolites, and Incident Cardiovascular Disease Among Older Adults: The Cardiovascular Health Study

ARTICLE PUBLICATION DATE

1-Aug-2022

COI STATEMENT

D. Mozaffarian reports research funding from the National Institutes of Health, the Gates Foundation, The Rockefeller Foundation, Vail Innovative Global Research, and Kaiser Permanente; personal fees from Acasti Pharma, Barilla, Danone, and Motif FoodWorks; scientific advisory board, Beren Therapeutics, Brightseed, Calibrate, Discern Dx, Elysium Health, Filtricine, HumanCo, January Inc, Perfect Day, Tiny Organics, and (ended) Day Two and Season Health; stock ownership in Calibrate and HumanCo; and chapter royalties from UpToDate. Z. Wang and S.L. Hazen report being named as coinventor on pending and issued patents held by the Cleveland Clinic relating to cardiovascular diagnostics and therapeutics. S.L. Hazen also reports being a paid consultant for Zehna Therapeutics and having received research funds from Procter & Gamble, Zehna Therapeutics and Roche Diagnostics. Z. Wang and S.L. Hazen report being eligible to receive royalty payments for inventions or discoveries related to cardiovascular diagnostics or therapeutics from Cleveland Heart Lab, and Procter & Gamble, and S.L. Hazen from Zehna Therapeutics. B.M. Psaty serves on the Steering Committee of the Yale Open Data Access Project funded by Johnson & Johnson. The other authors report no conflicts.

Increased heart disease risk from red meat may stem from gut microbe response to digestion

ATVB News release

Peer-Reviewed Publication

AMERICAN HEART ASSOCIATION

DALLAS, August 1, 2022 — Chemicals produced in the digestive tract by gut microbes after eating red meat may help explain part of the higher risk of cardiovascular disease associated with red meat consumption, according to new research published today in the American Heart Association’s peer-reviewed journal Arteriosclerosis, Thrombosis, and Vascular Biology (ATVB).

In the United States and around the world, cardiovascular disease is the leading cause of death. While the risk of developing cardiovascular disease, including heart attack and stroke, increases with age, other risk factors are influenced by lifestyle. Lifestyle and behaviors that are known to improve cardiovascular health include eating healthy foods, especially fruits and vegetables; regular physical activity; obtaining sufficient sleep; maintaining a healthy body weight; stopping smoking; and controlling high blood pressure, high cholesterol and high blood sugar.

“Most of the focus on red meat intake and health has been around dietary saturated fat and blood cholesterol levels,” said co-lead author of the study Meng Wang, Ph.D., a postdoctoral fellow at the Friedman School of Nutrition Science and Policy at Tufts University in Boston. “Based on our findings, novel interventions may be helpful to target the interactions between red meat and the gut microbiome to help us find ways to reduce cardiovascular risk.”

Previous research has found that certain metabolites — chemical byproducts of food digestion — are associated with a greater risk of cardiovascular disease . One of these metabolites is TMAO, or trimethylamine N-oxide, which is produced by gut bacteria to digest red meat that contains high amounts of the chemical L-carnitine .

High blood levels of TMAO in humans may be associated with higher risks of CVD, chronic kidney disease and Type 2 diabetes. However, whether TMAO and related metabolites derived from L-carnitine may help explain the effects of red meat intake on cardiovascular risk, and to what extent they may contribute to cardiovascular risk associated with meat consumption, are still unknown.

To understand these questions, the researchers conducting this study measured levels of the metabolites in blood samples. They also examined whether blood sugar, inflammation, blood pressure and blood cholesterol may account for the elevated cardiovascular risk associated with red meat consumption.

Study participants included nearly 4,000 of the 5,888 adults initially recruited from 1989 to 1990 for the Cardiovascular Health Study (CHS). The participants selected for the current study were free of clinical cardiovascular disease at time of enrollment in the CHS, an observational study of risk factors for cardiovascular disease in adults aged 65 or older. The CHS follows 5,888 participants recruited from four communities: Sacramento, California; Hagerstown, Maryland; Winston-Salem, North Carolina; and Pittsburgh, Pennsylvania. The average age of participants at enrollment was 73, nearly two-thirds of participants were female and 88% of participants self-identified as white. The median follow-up time for participants was 12.5 years, and up to 26 years in some cases.  At follow-up appointment, participants’ medical history, lifestyle, health conditions and sociodemographic characteristics — such as household income, education and age — were assessed.

Several blood biomarkers were measured at the start of the study and again in 1996-1997. The fasting blood samples stored frozen at -80 ˚C were tested for levels of several gut-microbiome linked to red meat consumption including TMAO, gamma-butyrobetaine and crotonobetaine.

Additionally, all study participants answered two validated food-frequency questionnaires about their usual dietary habits, including intake of red meat, processed meat, fish, poultry and eggs, at the start of the study and again from 1995 to 1996. For the first questionnaire, participants indicated how often, on average in the previous 12 months, they had eaten given amounts of various foods, ranging from “never” to “almost every day or at least five times per week,” based on medium portion sizes, which varied based on the food source. The second questionnaire used a ten-category frequency of average intake over the past 12 months, ranging from “never or less than once per month” to “six+ servings per day,” with defined standard portion sizes.

For the current analyses, the researchers compared the risk of cardiovascular disease among participants who ate different amounts of animal source foods (i.e., red meat, processed meat, fish, chicken and eggs). They found that eating more meat, especially red meat and processed meat, was linked to a higher risk of atherosclerotic cardiovascular disease - a 22% higher risk for about every 1.1 serving per day .

According to the authors, the increase in TMAO and related metabolites found in the blood explained roughly one-tenth of this elevated risk. They also noted that blood sugar and general inflammation pathways may help explain the links between red meat intake and cardiovascular disease. Blood sugar and inflammation also appear to be more important in linking red meat intake and cardiovascular disease than pathways related to blood cholesterol or blood pressure. Intake of fish, poultry and eggs were not significantly linked to higher risk of cardiovascular disease.

“Research efforts are needed to better understand the potential health effects of L-carnitine and other substances in red meat such as heme iron, which has been associated with Type 2 diabetes, rather than just focusing on saturated fat,” Wang said. 

The study had several limitations that may have affected its results. The study was observational, meaning it could not control for all risk factors for cardiovascular disease, and may not prove cause and effect between meat consumption and cardiovascular disease or its mediation by gut microbe-generated chemicals. Additionally, food consumption was self-reported, so errors in reporting were possible. And, as most of the study participants were older, white men and women in the United States, the findings may not apply to populations that are younger or more racially diverse.

The co-lead author is  Zeneng Wang, Ph.D. Co-authors are Yujin Lee, Ph.D.; Heidi T.M. Lai, Ph.D.; Marcia C. de Oliveira Otto, Ph.D.; Rozenn N. Lemaitre, Ph.D., M.P.H.; Amanda Fretts, Ph.D., M.P.H.; Nona Sotoodehnia, M.D., M.P.H.; Matthew Budoff, M.D.; Joseph A. DiDonato, Ph.D.; Barbara McKnight, Ph.D.; W. H. Wilson Tang, M.D.; Bruce M. Psaty, M.D., Ph.D.; David S. Siscovick, M.D., M.P.H.; Stanley L. Hazen, M.D., Ph.D.; and Dariush Mozaffarian, M.D., Dr.Ph. Authors’ disclosures are listed in the manuscript.

The study was funded by the National Heart, Lung, and Blood Institute, with additional support from the National Institutes of Health, the National Institute of Neurological Disorders and Stroke, and the National Institute on Aging.

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:

• After August 1, view the manuscript online : https://newsroom.heart.org/news/increased-heart-disease-risk-from-red-meat-may-stem-from-gut-microbe-response-to-digestion?preview=0fd5e9bc554d43ed9d4b5619a314bab3
• AHA news release: Eating protein from a greater variety of sources may lower risk of high blood pressure (April 2022)
• AHA news release: Eating more plant foods may lower heart disease risk in young adults, older women (August 2021)
• AHA Scientific Statement: 2021 Dietary Guidance to Improve Cardiovascular Health: A Scientific Statement From the American Heart Association  (November 2021)
• Follow AHA/ASA news on Twitter @HeartNews
• Follow news from the AHA’s Arteriosclerosis, Thrombosis, and Vascular Biology (ATVB) journal @atvbahajournals

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

Arteriosclerosis Thrombosis and Vascular Biology

DOI

10.1161/ATVBAHA.121.316533 

POSTMODERN ALCHEMY

NUS study: Black cardamom effective against lung cancer cells

NATIONAL UNIVERSITY OF SINGAPORE

NUS researchers embarked on a scientific study of black cardamom, a spice used in Indian Ayurvedic medicine, as a source of potent bioactive compounds that are effective against lung cancer cells. view more
Credit: National University of Singapore

The main challenges associated with existing lung cancer drugs are severe side effects and drug resistance. There is hence a constant need to explore new molecules for improving the survival rate and quality of life of lung cancer patients.

In Indian Ayurvedic medicine, black cardamom has been used in formulations to treat cancer and lung conditions. A team of researchers from the NUS Faculty of Science, NUS Yong Loo Lin School of Medicine, and NUS College of Design and Engineering studied the scientific basis behind this traditional medicinal practice and provided evidence of the cytotoxic effect of black cardamom on lung cancer cells. The research highlighted the spice as a source of potent bioactives, such as cardamonin and alpinetin, which could be used in the treatment or prevention of lung cancer. The study is the first to report the association of black cardamom extract with oxidative stress induction in lung cancer cells, and compare the spice’s effects on lung, breast and liver cancer cells.

The findings could potentially lead to the discovery of safe and effective new bioactives which can prevent or cure cancer formation. The research was first published in the Journal of Ethnopharmacology in December 2021.

Delving into the science behind Ayurveda

The research provides the verification of ethnomedical uses of black cardamom for its effect on lung-related conditions. Black cardamom is typically used in Asian households in rice preparations, curries and stews either as a whole spice or in powdered form. The spice is also prescribed in Indian Ayurvedic medicine in powder form where it is used for conditions such as cough, lung congestion, pulmonary tuberculosis, and throat diseases. In addition, black cardamom has been used in medicine formulations for cancer patients in some rural and tribal cultures in India.

In the NUS study, black cardamom fruits were powdered and sequentially extracted with five types of solvents, including organic solvents and water. This allowed the researchers to evaluate the best solvents to extract the most potent actives in the fruit. The various types of black cardamom extracts were then tested for their cytotoxicity against several types of cancer cells. These included cancer cells from the lung, liver and breast. Among the three types of cells, lung cancer cells were least likely to survive when tested with the black cardamom extracts.

“The study lays the foundation for further study on whether consuming black cardamom can prevent, or help as a therapeutic for, lung cancer. Previous research papers on black cardamom’s effects on cancer were preliminary and did not link research findings with the use of black cardamom in traditional medicine. There was also not enough screening done using different cancer cells to understand which cancer cells were most responsive to black cardamom extracts,” said Pooja Makhija, a doctoral student from the Department of Chemistry at NUS Faculty of Science.

The sequential extraction method using hexane followed by dichloromethane produced a black cardamom extract that was most effective against lung cancer cells. Dichloromethane extract treated cells were found to be killed mainly by apoptotic pathway where the measure of live cells, dropped to less than an average of about 20 percent after 48 hours of contact with the black cardamom extracted using dichloromethane. Cell death was caused by apoptosis with cells displaying morphological changes, such as shape distortion and shrinkage, increased oxidative stress, and a failure in DNA damage repair.

After running the black cardamom extract though liquid chromatography mass spectrometry analysis, the researchers linked the presence of two well-researched bioactives, cardamonin and alpinetin, to the cytotoxic potential of black cardamom.

“With black cardamom being commonly used as an important spice in cooking, further in-depth investigation about its impact on lung cancer progression in the pre-clinical models can provide strong evidence in support of the “food as medicine” philosophy of Hippocrates that has been neglected to great extent in the present day,” said Associate Professor Gautam Sethi from the Department of Pharmacology at the NUS Yong Loo Lin School of Medicine, who was a collaborator for the research.

Potential applications for cancer research

“The black cardamom extract used in the study can potentially be used to isolate and identify more novel chemical compounds that can be effective against cancer cells. These new actives could then undergo cellular, pre-clinical and clinical testing for further development into drugs for treating cancer,” said co-principal investigator Adjunct Associate Professor Bert Grobben from Department of Industrial Systems Engineering and Management at the NUS College Design of Engineering.

Āyurveda and Alchemy – Fontana Editore

Monkeypox: New agents to combat a dangerous pathogen

Grant and Award Announcement

UNIVERSITY OF WÜRZBURG

The coronavirus pandemic is far from over, and already another virus is causing a stir: “International outbreak of monkeypox” was the cry in the media a few weeks ago, followed by daily headlines along the lines of “first case of monkeypox in Baden-Württemberg, Bavaria, Berlin and so on”. Subsequent reports, like that of Bavaria’s public broadcasting service Bayerischer Rundfunk – “Study: monkeypox pathogen mutates faster than expected” – or that of the German weekly news magazine Der Spiegel – “Doctor says of monkeypox: ‘We have gone past the point in time where the virus could still have been stopped completely’”, did nothing to calm the situation.

And at the latest since the World Health Organisation (WHO) declared the monkeypox outbreak in more than 50 countries an "emergency of international concern" on 23 July, it should be clear to everyone: Viruses can cross species barriers at any time and cause novel diseases, known as zoonoses, in humans. In extreme cases, they can even trigger another pandemic.

Innovative approaches to drug development

Given this context, it seems more than fitting that the University of Würzburg (JMU) is now launching a new research project that deals with this very topic. “A structure-based approach to combat zoonotic poxviruses” is its title.

This project, with funding of around EUR 700,000 from the Volkswagen Foundation, is headed by Professor Utz Fischer, Chair of Biochemistry at JMU, and his colleague Dr Clemens Grimm. Also on board is Intana Bioscience GmbH, a biotech company based near Munich with a special interest in the development of new agents. Poxviruses are the focus of this project.

Poxviruses carry a high risk potential

“We know that animals carry many types of viruses in their organism that can pose a threat to humans,” says Utz Fischer. Unfortunately, it is impossible to predict which of them will be the next to make the jump across species barriers. However, it is clear that some viruses have a higher potential than others and are therefore more threatening to humanity, with poxviruses right at the top of this list. The aim of the project is therefore to conceive new approaches to developing novel drugs against pox pathogens. To this end, the scientists are looking for substances that interfere with the viral transcription process and thus prevent the viruses from multiplying.

Fischer and his team can draw on findings that they presented to the public last autumn. “We succeeded in visualising the poxviral gene expression machinery at the atomic level,” explains the biochemist. These studies therefore allow to observe how the molecular machinery acts when the virus multiplies. The images show in detail how the players involved operate during the early phase of transcription. The short videos can be seen on the university's YouTube channel:

https://www.youtube.com/watch?v=9Ij9iFks-NE

https://www.youtube.com/watch?v=KPHGoHxsAOA

An approach that can also be applied to swine fever

With the search for agents that can inhibit these molecular machines, the team can exploit a special circumstance: While many viruses draw extensively on the biochemical resources of the host cell for their multiplication, poxviruses encode their own molecular machinery in their genome for this purpose. Important components of this machinery are two enzymes: DNA polymerase, which multiplies the viral genes, and RNA polymerase, which transcribes the viral genes into mRNA.

This unique replication strategy offers the opportunity to search for inhibitors of key viral complexes and enzymes that attack at this exact point and thus spare the host cells, ideally making them free from side effects. Should the team succeed in identifying and designing such molecules, they might even kill two birds with one stone: “Because the transcription machineries of Poxviridae and Asfarviridae are highly similar, our research is also likely to be of relevance for the economically highly threatening Asfarvirus-linked swine fever disease,” says Fischer.

Technical progress helps the research

What is most helpful to the scientists in their work are technical advances. One of these is a significant increase in the resolution of cryo-electron microscopic images. With this technology, samples are “flash-frozen” to temperatures of up to minus 180 degrees Celsius. This is what makes it possible to examine biological molecules and complexes in solution and to reconstruct their three-dimensional structure on the scale of atoms.

The JMU has had a suitable electron microscope for many years. “Many medically relevant target molecules are therefore becoming the focus of drug design. We will use this technology alongside established methods to identify molecules that target the special structures of poxviruses and disrupt their multiplication,” explains Clemens Grimm, who carries out structural biology analyses at the department.

Indeed, the scientists involved are optimistic that they will succeed over the coming years in defining a number of chemical compounds that can serve as a kind of guiding structure for the subsequent development of a pharmaceutical product.

Poxviruses are a threat for several reasons

It is, of course, a coincidence that the research team is starting its work at the same time as this outbreak of monkeypox – the application was written months ago. But what is not a coincidence is that the scientists are focusing on poxviruses. After all, these pose a potential threat to humanity for various reasons. For one thing, there are currently very few antiviral drugs available, and these often display very limited potency.

In addition, while there is effective protection against pox infection in the form of vaccination, after the World Health Organization (WHO) declared smallpox eradicated in 1980, the corresponding vaccination campaigns were terminated in the ensuing years. Since then, herd immunity to poxviruses has been noticeably dwindling in humans. It is no wonder that a recent study ranks the monkeypox virus as one of the most threatening viruses because of the risk of infecting humans, adapting to its new host through mutations and then spreading exponentially.

How color in photos can make food look tastier

Study finds saturation in images is key to marketing menu items

Peer-Reviewed Publication

OHIO STATE UNIVERSITY

 

IMAGE: THE PHOTO ON THE LEFT OF A POKE BOWL DOESN'T LOOK AS FRESH AND TASTY TO VIEWERS AS THE ONE ON THE RIGHT. view more 

CREDIT: OHIO STATE UNIVERSITY

COLUMBUS, Ohio – An appealing photo of a pizza or other menu item can help a restaurant increase sales – especially if the right filter is used, a new study suggests.

Photos high in color saturation make food look fresher and tastier to viewers, which increases their willingness to order the menu items, researchers found.

Color saturation refers to the intensity of the color in the image – the vividness and richness of the reds and greens and blues.

But how well color saturation works to make food appealing depends on the visual distance of the food in the photo – and even on whether consumers plan to dine alone or with others.

In the cutthroat restaurant business, these results provide a simple method to increase sales, said Stephanie Liu, lead author of the study and associate professor of hospitality management at The Ohio State University.

“On Instagram, it means using the ‘X-Pro II’ filter on your food photos rather than the ‘Earlybird’ filter,” Liu said. “It is not difficult and doesn’t cost a dime, so it is an easy win for restaurant marketers.”

The study was published online recently in the Journal of Business Research.

The researchers did two online studies.

In one study, 267 participants were asked to imagine themselves browsing through options on an online food ordering platform.

They were shown photos of a poke bowl, a Hawaiian dish featuring chunks of raw, marinated fish, vegetables and sauce over rice.  They were from a fictitious restaurant named Poke Kitchen.

Study participants were randomly assigned to view one of the four different photos with either high or low color saturation and either close or farther away visual distance.

The photos with high color saturation were edited with professional graphic design software to be 130% more saturated than the low-saturation photos. The up-close photos were 130% larger in radius and appeared nearer to the observer than the more distant photo.

Participants were asked to rate how fresh the food in each photo looked, how tasty it looked and how likely they would be to purchase it.

The food in the more highly saturated photos looked fresher and tastier to participants, and that led them to be more likely to purchase the food, results showed.

But color saturation had a stronger effect when the food appeared more distant in the photos, Liu said.

“When the food is shown close up, it is already easy for the viewers to imagine how fresh and tasty the food would be,” she said. “Color saturation is not as necessary.”

The second study involved 222 online participants.  In this case, the participants were asked to imagine they were browsing Instagram and came across images of pizza from a fictitious restaurant near their home named Pizza City. They were shown photos either high or low in color saturation.

People in the study were also told they would either be eating alone or with family that night and were again asked to rate the pizza on perceived freshness and tastiness and on whether they would likely purchase the menu item.

As in the previous study, the food in the color-saturated photo was always seen as fresher and tastier and one that people would be more likely to buy.  But that effect was stronger for people who were told they would be eating alone and weaker for those who would be eating with family.

“When people are eating with others, the social experience is a big part of what people look forward to,” Liu said.

“But when they anticipate eating alone, they focus more on the food itself. They want the food to be fresher and tastier and that’s why color saturation is more important in this context.”

These findings are more important now than ever before, with people ordering online and looking at photos to help them decide what to eat, Liu said.

“Restaurants have to post pictures of their food on social media and online ordering platforms,” she said.

“They should be paying as much attention, or maybe more, to the photos they post as they do to the text. Color saturation is one key element they need to focus on.”

Co-authors on the study were Laurie Luorong Wu of Temple University, Xi Yu of the City University of Macau and Huiling Huang of the University of Macau in China. Xi Yu and Huiling Huang are recent doctoral graduates of the hospitality management program at Ohio State.

JOURNAL

Journal of Business Research

DOI

10.1016/j.jbusres.2022.06.061 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Marketing online food images via color saturation: A sensory imagery perspective

Investment urgently needed in new technology to mitigate CO2 emissions at airports, Cranfield University report reveals

Reports and Proceedings

CRANFIELD UNIVERSITY

• Multi-million-pound investment needed in technologies such as direct air capture
• Some airports could become green energy ‘power stations’ to fuel the aircraft they serve
• Carbon capture technology should be integrated alongside other transport policies as part of Government’s Net Zero 2050 roadmap

Multi-million-pound investment is urgently needed in technologies including direct air capture (DAC) if the UK is to make ‘green’ airports a reality in the future, research by Cranfield University has revealed.

In the first study of its kind focusing primarily on emissions from the operational aspects of airports, researchers looked at how carbon capture, utilisation and sequestration (CCUS) technologies could be deployed across the sector to help some airports effectively become green energy ‘power stations’ to fuel the aircraft they serve for achieving the true net zero target.

DAC works by capturing CO2 in the air and then either sequestrating it or using it to manufacture carbon neutral fuel.

The report – which was compiled for the world’s leading specialist in air transport technology, SITA, – examined 2019 emissions and other information from London Luton Airport (LTN), Aberdeen Airport (ABZ), Indira Gandhi International Airport in India (DEL) and San Francisco International Airport (SFO).

Direct Air Capture, green hydrogen and SAF (sustainable aviation fuel)

The researchers said that a combination of integrating renewable green hydrogen technology (generated by renewable energy or low carbon power) with DAC and sustainable aviation fuel, (SAF) would help in the UK’s Net Zero ambitions. The report added that as part of the Government’s Net Zero 2050 roadmap, CCUS should be included alongside other air transport energy policies.

Dr Chikage Miyoshi, a co-author of the report from Cranfield University and lead for the university’s new Sustainable Aviation Systems Laboratory, said: “Carbon abatement measures have the potential to revolutionise the concept of aerospace sustainability, particularly through CCUS at airports.

“The case airports involved in this report recorded CO2 emissions in the range of 50 to 100 kilo tonnes of CO2 per annum. This indicates the potential of direct air capture in an airport environment.

“A combination of integrating renewable green hydrogen technology with DAC and SAF could be the ideal solution for achieving true net zero.

“This all requires long-term investment and strong leadership alongside an integrated energy policy and incentive scheme to facilitate such changes. In the long-run, we could see some airports act as power stations to fuel sustainable air transport operations.”

CCUS has both engineering and nature-based solutions

Six different types of CCUS engineering-based solutions were examined as part of the report. These can be combined with nature-based solutions for mitigating CO2 emissions, including tree planting and wetland restoration.

“Although the land required for DAC is relatively small” said Dr Miyoshi, “the initial investment is large. However, when we compute the operating cost to abate CO2 per passenger, it represents value for money.

“There are various sources of emissions at an airport ranging from electrical generation through to ground operations. Emissions from passenger surface access (the way customers reach the airport) are the second largest emissions source after aircraft emissions.

“Based on current technology, it is estimated that for CCUS engineering measures at Luton Airport, up to 0.04-2.5 km2 would be required. Some aspects could be introduced by airports working with local power stations.”

London Luton Airport Head of Sustainability, David Vazquez, said: “This collaboration provides timely, valuable insight into carbon capture and storage technologies and innovations, some of which we will explore further as we develop our evolving net zero roadmap.

“Although we recognise there will be some emissions that we cannot reduce in the short-term, London Luton Airport is committed to achieving carbon neutrality in 2023 and net zero for airport operations by 2040. This study is an example of the way in which LLA is working with the wider industry to look at the potential of emerging carbon capture technologies”.

Dr. Carlos Kaduoka, Head of Airport Business Strategy, SITA, said: “SITA is committed to reducing its climate impact and building a more sustainable air transport industry.

“Contributing to the research by Cranfield University is one example of our collaborative industry approach to exploring new ways to help decarbonize the industry and reach net-zero emissions.”

The report – The viability of Carbon Capture at Airports using Innovative Approaches – will be published at the end of August on the Cranfield University website.

Weed zapping

Do electrocution treatments have a place in weed control?

Peer-Reviewed Publication

CAMBRIDGE UNIVERSITY PRESS

Researchers from the University of Missouri recently conducted two field studies to explore the effectiveness of electricity in weed control. They used a tractor attachment called The Weed Zapper™ to electrocute eight types of weeds common in soybean crops, including herbicide-resistant waterhemp.

The first study showed that control was more effective in the later stages of weed growth and was most closely related to plant height and the moisture in the plant at the time of electrocution. Once the weeds had set seed, the treatments reduced viability by 54 to 80 percent across the weed species evaluated. A second study showed electrocution reduced late-season, herbicide-resistant waterhemp plants by 51 to 97 percent.

At some stages of growth, the soybean crops exhibited yield losses of 11 to 26 percent following electrocution treatments – though researchers say those results likely represent a worse-case scenario. In late-season treatments, for example, the clear height differential between waterhemp and the soybean canopy means the electrocution device can treat the weed without sustained contact with the crop.

The net takeaway: When used as part of an integrated control program, electrocution can eliminate many late-season, herbicide-resistant weed escapes in soybean crops and reduce the number and viability of weed seeds that return to the soil seedbank. 

Want to know more? Read the article “The Impact of Electrocution Treatments on Weed Control and Weed Seed Viability in Soybean” featured in the latest edition of the journal Weed Technology.

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JOURNAL

Weed Technology

DOI

10.1017/wet.2022.56 

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

The Impact of Electrocution Treatments on Weed Control and Weed Seed Viability in Soybean

Fiddler crab eye view inspires Gwangju Institute of Science and Technology researchers to develop novel artificial vision

The researchers develop an amphibious artificial vision system with a panoramic field-of-view based on the Fiddler crab’s eye structure

Peer-Reviewed Publication

GIST (GWANGJU INSTITUTE OF SCIENCE AND TECHNOLOGY)

 

IMAGE: RESEARCHERS FROM GWANGJU INSTITUTE OF SCIENCE AND TECHNOLOGY IN KOREA HAVE DEVELOPED, IN A NEW STUDY, AN ARTIFICIAL VISION SYSTEM MODELED AFTER THE FIDDLER CRAB EYE STRUCTURE, WHICH IS SUITABLE FOR BOTH LAND AND UNDERWATER ENVIRONMENTS, AND PROVIDES A PANORAMIC IMAGING ABILITY. view more 

CREDIT: PROF. YOUNG MIN SONG FROM GIST, KOREA

Artificial vision systems find a wide range of applications, including self-driving cars, object detection, crop monitoring, and smart cameras. Such vision is often inspired by the vision of biological organisms. For instance, human and insect vision have inspired terrestrial artificial vision, while fish eyes have led to aquatic artificial vision. While the progress is remarkable, current artificial visions suffer from some limitations: they are not suitable for imaging both land and underwater environments, and are limited to a hemispherical (180°) field-of-view (FOV).

To overcome these issues, a group of researchers from Korea and USA, including Professor Young Min Song from Gwangju Institute of Science and Technology in Korea, have now designed a novel artificial vision system with an omnidirectional imaging ability, which can work in both aquatic and terrestrial environments. Their study was made available online on 12 July 2022 and published in Nature Electronics on 11 July 2022.

“Research in bio-inspired vision often results in a novel development that did not exist before. This, in turn, enables a deeper understanding of nature and ensure that the developed imaging device is both structurally and functionally effective,” says Prof. Song, explaining his motivation behind the study.

The inspiration for the system came from the fiddler crab (Uca arcuata), a semiterrestrial crab species with amphibious imaging ability and a 360° FOV. These remarkable features result from the ellipsoidal eye stalk of the fiddler crab’s compound eyes, enabling panoramic imaging, and flat corneas with a graded refractive index profile, allowing for amphibious imaging.

Accordingly, the researchers developed a vision system consisting of an array of flat micro-lenses with a graded refractive index profile that was integrated into a flexible comb-shaped silicon photodiode array and then mounted onto a spherical structure. The graded refractive index and the flat surface of the micro-lens were optimized to offset the defocusing effects due to changes in the external environment. Put simply, light rays traveling in different mediums (corresponding to different refractive indices) were made to focus at the same spot.

To test the capabilities of their system, the team performed optical simulations and imaging demonstrations in air and water. Amphibious imaging was performed by immersing the device halfway in water. To their delight, the images produced by the system were clear and free of distortions. The team further showed that the system had a panoramic visual field, 300o horizontally and 160o vertically, in both air and water. Additionally, the spherical mount was only 2 cm in diameter, making the system compact and portable.

“Our vision system could pave the way for 360° omnidirectional cameras with applications in virtual or augmented reality or an all-weather vision for autonomous vehicles,” speculates Prof. Song excitedly.

And it might be soon!

***

Reference

DOI: https://doi.org/10.1038/s41928-022-00789-9

Authors: Mincheol Lee1,2, Gil Ju Lee3,4, Hyuk Jae Jang3, Eehyung Joh1,2, Hyojin Cho1,2, Min Seok Kim3, Hyun Myung Kim3, Kyeong Muk Kang3, Joong Hoon Lee3, Myungbin Kim1,2, Hongwoo Jang5, Ji-Eun Yeo3, Frédo Durand6, Nanshu Lu5,7,9,10,11, Dae-Hyeong Kim1,2,8, and Young Min Song3

Affiliations:        

1Center for Nanoparticle Research, Institute for Basic Science (IBS)

2School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University

3School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology

4Department of Electronics Engineering, Pusan National University

5Texas Materials Institute, University of Texas at Austin

6Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology

7Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin

8Department of Materials Science and Engineering, Seoul National University

9Department of Electrical and Computer Engineering, The University of Texas at Austin

10Department of Biomedical Engineering, The University of Texas at Austin, Austin

11Department of Mechanical Engineering, The University of Texas at Austin

 

About the Gwangju Institute of Science and Technology (GIST)

The Gwangju Institute of Science and Technology (GIST) is a research-oriented university situated in Gwangju, South Korea. Founded in 1993, GIST has become one of the most prestigious schools in South Korea. The university aims to create a strong research environment to spur advancements in science and technology and to promote collaboration between international and domestic research programs. With its motto of “A Proud Creator of Future Science and Technology,” GIST has consistently received one of the highest university rankings in Korea.

Website: http://www.gist.ac.kr/

 

About the authors

Young Min Song is currently a Professor in the School of Electrical Engineering and Computer Science at Gwangju Institute of Science and Technology (GIST), Korea. He received his Ph.D. in Information and Communications from GIST in 2011. From 2011 to 2013, he was a postdoctoral research associate in the Department of Materials Science and Engineering at the University of Illinois at Urbana-Champaign (UIUC), USA. Over the decades, he has predominantly focused his efforts on developing bio-inspired optics and photonics. His group is developing advanced optoelectronic sensors and systems, multifunctional nanophotonics, and optical healthcare systems.

Dae-Hyeong Kim obtained Ph. D. degree in Materials Science and Engineering from University of Illinois at Urbana Champaign (UIUC) in 2009. He was a post-doctoral research associate at UIUC from 2009 to 2011. He joined Seoul National University in 2011 and is currently a Professor in the School of Chemical and Biological Engineering at Seoul National University. Since 2017, he has also served as an associate director of Center for Nanoparticle Research at Institute for Basic Science (IBS). He has been focusing on the research of nanomaterials and deformable devices and their application to bio-integrated and bio-inspired electronics.

Mincheol Lee is a post-doctoral research associate at Seoul National University. He received his Ph. D. degree in the School of Chemical & Biological Engineering from Seoul National University in 2021. He has been focusing on the research of stretchable electronics based on ultrathin semiconductor films and their application to wearable, implantable, and bio-inspired electronics.

Gil Ju Lee is currently serving as an Assistant Professor in the Department of Electronics Engineering at Pusan National University since 2021. He has intensely focused on the research of advanced photonics and optics for next-generation optoelectronics and optical systems. Before coming to Pusan National University, he completed his Postdoctoral training and doctoral course at Gwangju Institute of Science and Technology (GIST).

Hyuk Jae Jang received his B.S. from Department of Physical and Semiconductor Science at Dongguk University and is a Ph. D. candidate under the guidance of Prof. Young Min Song in GIST. His current research interests focus on bio-inspired nano-optics and imaging device systems.

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JOURNAL

Nature Electronics

DOI

10.1038/s41928-022-00789-9 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

An amphibious artificial vision system with a panoramic visual field

RESEARCH NEWS - Turning Fish Waste into Quality Carbon-based Nanomaterial

: August 1, 2022

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Thanks to their low toxicity, chemical stability, and remarkable electrical and optical properties, carbon-based nanomaterials are finding more and more applications across electronics, energy conversion and storage, catalysis, and biomedicine. Carbon nano-onions (CNOs) are certainly no exception. First reported in 1980, CNOs are nanostructures composed of concentric shells of fullerenes, resembling cages within cages. They offer multiple attractive qualities such as a high surface area and large electrical and thermal conductivities.

Unfortunately, the conventional methods for producing CNOs have some serious drawbacks. Some require harsh synthesis conditions, such as high temperatures or vacuum, while others demand a lot of time and energy. Some techniques can circumvent these limitations, but instead call for complex catalysts, expensive carbon sources, or dangerous acidic or basic conditions. This greatly limits the potential of CNOs.

Fortunately, not all hope is lost. In a recent study published in Green Chemistry (available online on April 25, 2022, and published in issue 10 on May 21, 2022), a team of scientists from Nagoya Institute of Technology in Japan found a simple and convenient way to turn fish waste into extremely high-quality CNOs. The team, which included Assistant Professor Yunzi Xin, Master's student Kai Odachi, and Associate Professor Takashi Shirai, developed a synthesis route in which fish scales extracted from fish waste after cleaning are converted into CNOs in mere seconds through microwave pyrolysis.

But how can fish scales be converted into CNOs so easily? While the exact reason is not altogether clear, the team believes that it has to do with the collagen contained in fish scales, which can absorb enough microwave radiation to produce a fast rise in temperature. This leads to thermal decomposition or "pyrolysis," which produces certain gases that support the assembly of CNOs. What is remarkable about this approach is that it needs no complex catalysts, nor harsh conditions, nor prolonged wait times; the fish scales can be converted into CNOs in less than 10 seconds!

Moreover, this synthesis process yields CNOs with very high crystallinity. This is remarkably difficult to achieve in processes that use biomass waste as a starting material. Additionally, during synthesis, the surface of the CNOs is selectively and thoroughly functionalized with (−COOH) and (−OH) groups. This is in stark contrast to the surface of CNOs prepared with conventional methods, which is typically bare and has to be functionalized through additional steps.

This "automatic" functionalization has important implications for applications of CNOs. When the CNO surface is not functionalized, the nanostructures tend to stick together owing to an attractive interaction known as pi−pi stacking. This makes it difficult to disperse them in solvents, which is necessary in any application requiring solution-based processes. However, since the proposed synthesis process produces functionalized CNOs, it allows for an excellent dispersibility in various solvents.

Yet another advantage associated with functionalization and the high crystallinity, is that of exceptional optical properties. Dr. Shirai explains: "The CNOs exhibit ultra-bright visible-light emission with an efficiency (or quantum yield) of 40%. This value, which has never been achieved before, is about 10 times higher than that of previously reported CNOs synthesized via conventional methods."

To showcase some of the many practical applications of their CNOs, the team demonstrated their use in LEDs and blue-light-emitting thin films. The CNOs produced a highly stable emission, both inside solid devices and when dispersed in various solvents, including water, ethanol, and isopropanol. "The stable optical properties could enable us to fabricate large-area emissive flexible films and LED devices," speculates Dr. Shirai. "These findings will open up new avenues for the development of next-generation displays and solid-state lighting."

Furthermore, the proposed synthesis technique is environmentally friendly and provides a straightforward way to convert fish waste into infinitely more useful materials. The team believes their work would contribute to the fulfillment of several of UN's Sustainable Development Goals. Additionally, if CNOs make their way into next-generation LED lighting and QLED displays, they could greatly help reduce their manufacturing costs.

Let us hope the efforts of these scientists tip the scales in favor of CNOs for more practical applications!

Figure 1. Converting fish scales into high-quality nanomaterials.
(Left) Scheme depicting the synthesis of carbon nano-onions via the microwave pyrolysis of fish scales. The top inset shows the rise in temperature of the fish scales due to microwave absorption over a period of 10 seconds, as well as a proposed formation mechanism for the carbon nano-onions.
(Right) transmission electron microscopy images showing the morphology of the synthesized carbon nano-onions and photographs of CNO dispersion in ethanol, an emissive flexible film, and an LED containing CNO.
Image credit: Takashi Shirai from NITech, Japan.

Reference

Title of original paper

Fabrication of ultra-bright carbon nano-onions via a one-step microwave pyrolysis of fish scale waste in seconds

Journal

Green Chemistry


DOI

10.1039/d1gc04785j

About Associate Professor Takashi Shirai

Dr. Takashi Shirai is an Associate Professor at Nagoya Institute of Technology (NITech), Japan at the Department of Life Science and Applied Chemistry and Advanced Ceramics Research Laboratory. He works in the field of functional materials synthesis, surface chemistry, and ceramics engineering. His expertise lies in the surface and interface engineering and characterizations of nanostructures and inorganic and composite materials. He has published more than 180 scientific papers in reputed journals, book chapters, and conference proceedings and 50 patents to his credit. He has received 11 awards from the Ceramics Society of Japan, The Society of Powder Technology, and The Association of Powder Process Industry and Engineering, among others.

Contact

Links : Shirai Group Energy Materials Lab.