ALCHEMY

The benefits of olive oil for health and wellbeing

Oleic acid, the principal component of olive oil, has properties that help to prevent cancer and Alzheimer’s disease and to lower cholesterol

Peer-Reviewed Publication

UNIVERSITY OF SEVILLE

The health benefits of olive oil, which are commonly attributed to its minor components such as polyphenols, are now well recognised by science. But little attention has been paid to oleic acid, which represents 70 to 80 percent of its composition. That is why a group of professors from the Faculties of Pharmacy and Medicine at the University of Seville, in conjunction with professionals from the Seville North and Aljarafe Health District and the Costa del Sol Hospital, have produced a study on its main contributions to health.

This fatty acid is the main constituent of olive oil and is responsible for many health-promoting properties. Oleic acid is produced by the diet and synthesis in the body itself. It is thereby the most abundant monounsaturated fatty acid (MUFA) in the human diet.

The Mediterranean diet is the most widely recognised diet for preventing disease and ageing. The olive tree (Olea europaea L.) is abundant in the Mediterranean basin and olive oil, which is extracted from its fruit, is the most characteristic nutrient and the main fat in this diet, which is also marked by a high vegetable intake, moderate fish consumption, low-moderate dairy consumption, low red meat intake and moderate wine consumption.

Oleic acid is the principal MUFA in the human circulatory system. In the brain, it is a major component of membrane phospholipids and abounds in the neuronal myelin sheaths. A significantly decreased level of oleic acid has been observed in the brains of patients suffering from major depressive disorders and Alzheimer’s disease.

Like all free fatty acids, oleic acid’s main function is that of an energy molecule and a component of cell membranes. One of its most characteristic effects is its antioxidant properties, since it can directly regulate both the synthesis and the activity of antioxidant enzymes. Another beneficial property is its hypocholesterolaemic effect: it inhibits the expression of proteins associated with cholesterol transport, reducing cholesterol absorption and thus preventing atherosclerosis.

Oleic acid is also recognised to be an anti-cancer molecule because of its inhibitory effects on the overexpression of oncogenes and their effects on programmed cell death. Moreover, oleic acid is generally considered an anti-inflammatory molecule, although this quality is still under debate among scientists.

On the other hand, oleoylethanolamide, a derivative of oleic acid, has anti-inflammatory and antioxidant effects of its own and has now been proposed as a potent therapeutic agent to treat obesity. This underlines the benefits of oleic acid for health. Emerging research suggests that it may influence epigenetic mechanisms (direct modifications of DNA and DNA-associated proteins) and modulation of the immune system, specifically by regulating cells involved in developing inflammation.

Finally, the authors of this study have pointed out that most studies on olive oil have been conducted on animals, hence they warn of the need for further research to confirm the significant properties shown by this molecule and its derivative, oleoylethanolamide, in humans.

---

JOURNAL

Nutrients

DOI

10.3390/nu15010224 

ARTICLE TITLE

Update on Anti-Inflammatory Molecular Mechanisms Induced by Oleic Acid

A labyrinth lake provides surprising benefits for an endangered seal

Peer-Reviewed Publication

UNIVERSITY OF HELSINKI

 

IMAGE: RESEARCHERS FROM THE UNIVERSITY OF HELSINKI TOGETHER WITH COLLEAGUES FROM THE UNIVERSITY OF EASTERN FINLAND AND THE UNIVERSITY OF COPENHAGEN COMPARED OVER 100 GENOMES OF SAIMAA RINGED SEALS PRESERVED IN A TISSUE BANK. view more 

CREDIT: MIA VALTONEN

The endangered Saimaa ringed seal is an Ice Age relict living in the highly labyrinthine Lake Saimaa, Finland. The newly published work shows that although individual seals have greatly reduced genetic variation, the loss of variation has been complementary, preserving the adaptive potential of the whole population.

Lake Saimaa, a highly labyrinthine lake in eastern Finland, provides a unique opportunity for assessing the effects of population fragmentation. The lake hosts a population of ringed seals (Pusa hispida saimensis) that became landlocked as the land rebounded after the retreat of the continental ice sheet 10 000 years ago. Today, the Saimaa ringed seal, with some 400 individuals, is one of the world's most endangered seals.

Researchers from the University of Helsinki together with colleagues from the University of Eastern Finland and the University of Copenhagen compared over 100 genomes of Saimaa ringed seals preserved in a tissue bank.

"The Saimaa ringed seals have gone through a severe population size contraction resulting in greatly reduced genetic variation. This raises concerns about their ability to adaptively respond to ongoing climate change," Petri Auvinen and Jukka Jernvall from the University of Helsinki say.

The analyses revealed that the genomes of individual seals contained long stretches of DNA sequences that were inherited identically from both parents. Comparisons of these homozygous regions among seals living in far-flung nooks of the lake revealed something unexpected. "The good news is that the labyrinthine shape of Lake Saimaa has generated three subpopulations that are homozygous for largely different, complementary parts of their genome. This means that the population as a whole has retained much of its original genetic variation," explains Ari Löytynoja from the University of Helsinki.

Modelling the population history of the Saimaa ringed seals further suggested that the intricate shape of Lake Saimaa has been optimal in compensating for the detrimental effects of small population size. Detailed analyses also revealed a beneficial genetic signature of a seal individual that was translocated decades ago from one part of the lake to another. For the conservation of other endangered species, the lesson learned from the labyrinthine Lake Saimaa is the importance of careful gene flow management among poorly connected populations.

---

JOURNAL

Current Biology

DOI

10.1016/j.cub.2023.01.040 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animal tissue samples

ARTICLE TITLE

Fragmented habitat compensates for the adverse effects of genetic bottleneck

ARTICLE PUBLICATION DATE

22-Feb-2023

First-of-its-kind study examines the impact of cannabis use on surgical patients' post-procedure healthcare needs

Cannabis use among surgical patients tripled in Massachusetts between 2008 and 2020; one in seven patients report use, study finds

Peer-Reviewed Publication

BETH ISRAEL DEACONESS MEDICAL CENTER

BOSTON – As legislation in multiple states eases former restrictions around medical and recreational cannabis in the United States, an increasing proportion of the population reports use of the drug. Between 2016 and 2018, more than 22 percent of Massachusetts residents reported any prior cannabis use for medical or recreational reasons. However, little is known about cannabis use in patients who undergo surgery or interventional procedures, where cannabis use has important additional clinical implications.

In a new study published in The Lancet’s eClinical Medicine, researchers led by anesthesiologists at Beth Israel Medical Center (BIDMC) analyzed de-identified data from patients who underwent non-cardiac surgery in Boston between 2008 and 2020. The scientists found that cannabis users had a higher complexity of co-existing conditions overall, including mood disorders such as depression and substance use disorders. Patients with a diagnosed cannabis use disorder more often required advanced postprocedural healthcare – such as admission to an intensive care unit – compared to non-users. However, patients whose use of cannabis was not classified as a disorder had lower odds of requiring advanced healthcare after surgery compared to patients who never use cannabis.

“Our analysis revealed that cannabis use is very common and has substantially increased among patients undergoing surgery, reflecting trends in the general population; however, differential effects on postprocedural health care utilization were observed between patients with moderate non-medical cannabis use and patients with a cannabis use disorder,” said corresponding author Maximillian S. Schaefer, Director of the Center for Anesthesia Research Excellence at BIDMC. “We hope our data helps make clinicians aware of how different patterns of cannabis use might represent different patient populations, which in turn translates into distinct perioperative risk profiles.”

In this hospital registry study, Schaefer and colleagues analyzed de-identified data from 210,639 adult patients undergoing noncardiac surgery at BIDMC between January 2008 and June 2020. Non-medical cannabis use was identified before procedures during routine, structured interviews about past and ongoing habits of drug use, in accordance with the American Society of PeriAnesthesia Nursing recommendations. Patients with cannabis use disorder were identified through diagnostic codes.

Over the entire study period, the researchers found that more than 16,000 patients, or 7.7 percent, used cannabis prior to surgery, of which 14,045 (87 percent) were identified as non-medical users and 2,166 (13 percent) had a diagnosis of cannabis use disorder. Of all the patients undergoing surgery, a total of 24,516 patients, or 12 percent, required advanced post-procedural healthcare utilization, among which 1,465 patients self-identified as non-medical cannabis users, 418 patients presented with cannabis use disorder and 22,633 patients had no reported ongoing cannabis use.

Overall, patients who self-identified as cannabis users were on average younger, more often male, and more likely to suffer from depression, anxiety and schizoaffective disorders. Substance use disorders related to alcohol, cocaine, IV drugs, prescription medications and psychedelic drugs were more frequent in patients who used cannabis.

“As these comorbidities have been associated with increased complications including arrhythmias and sudden cardiac death after anesthesia, a history of cannabis use disorder might serve as an indicator of potentially complicating factor for patients undergoing anesthesia that in turn contribute to the requirement of higher-level healthcare utilization after surgery,” Schaefer said.

Compared to patients who did not use cannabis, patients with a diagnosis of cannabis use disorder had higher odds of requiring advanced post procedural healthcare utilization. Specifically, a diagnosis of cannabis use disorder was linked with higher odds of a 30-day hospital readmission, compared to patients who did not use cannabis.

By contrast, patients with reported ongoing non-medical cannabis use had lower odds of advanced post-procedural healthcare unit utilization compared to patients who did not use cannabis. Moreover, such use was linked to shorter hospital length of stay than patients who did not use cannabis. Over the course of the study period, the scientists saw the prevalence of cannabis use rise from 5 percent in 2008 to 14 percent by 2020 and observed higher rates of cannabis use among those undergoing surgery than previous studies reported. While the scientists acknowledge the discrepancy could be the result of regional consumption patterns, they suggest their inclusion of ongoing self-reported non-medical cannabis users based on structured pre-admission interviews paints a more accurate picture than findings that identified patients’ cannabis use on diagnostic codes alone.

“This cohort represents a distinctively different patient population of more general non-medical users,” said Schaefer. “These differential findings in patients who self-identified as ongoing, non-medical cannabis users without a diagnosis of disorder strongly suggest that future studies need to differentiate these two patient populations. Findings based on the identification of cannabis use from diagnostic codes alone might not be applicable to most mainstream cannabis users.”

Co-authors included first author Elena Ahrens, Luca J. Wachtendorf, Laetitia S. Chiarella, Sarah Ashrafian, Aiman Suleiman, Tim M. Tartler, Basit A. Azizi, Guangqing Chen, Amnon A. Berge, Denys Shay, Valerie Banner-Goodspeed, Haobo Ma, and Kevin P. Hill, of BIDMC; Bijan Teja, of University of Toronto; and Matthias Eikermann of Albert Einstein College of Medicine.

This work was supported by an unrestricted, philanthropic grant of Jeff and Judy Buzen. Hill has served as a consultant for Greenwich Biosciences and has received an honorarium from Walters-Klewer as an author. Schaefer received funding for investigator-initiated studies from Merck and Co which do not pertain to this manuscript. Schaefer received honoraria for presentations from Fisher and Paykel healthcare and Mindray medical information international limited period. All other authors declare no competing interests.

About Beth Israel Deaconess Medical Center

Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School and consistently ranks as a national leader among independent hospitals in National Institutes of Health funding. BIDMC is the official hospital of the Boston Red Sox.

Beth Israel Deaconess Medical Center is a part of Beth Israel Lahey Health, a health care system that brings together academic medical centers and teaching hospitals, community and specialty hospitals, more than 4,800 physicians and 36,000 employees in a shared mission to expand access to great care and advance the science and practice of medicine through groundbreaking research and education.

---

JOURNAL

The Lancet

DOI

10.1016/j.eclinm.2023.101831 

Workers moving products in the U.S. food supply chain at high risk of injury

Peer-Reviewed Publication

PENN STATE

UNIVERSITY PARK, Pa. — Workers tasked with moving products in the immense U.S. food system are at a high risk of serious injury, according to a new Penn State-led study, and pandemic-caused, supply-chain problems have worsened the situation, researchers suggest.

The modern food supply chain presents unique hazards to employees that result in higher rates of death and injury when compared to most other industries, noted lead researcher Judd Michael, Penn State professor of agricultural and biological engineering. Employees in food manufacturing, wholesaling and even retailing experience relatively high numbers of occupational injuries and fatalities.

One reason for the high hazard rates may be the reliance on a synergistic packaging system designed to load and transport food products within and between manufacturers, wholesalers and retailers, Michael noted. In the modern system, food products are aggregated and transported after they have been packaged, requiring potentially dangerous machinery, equipment and methods to accomplish those tasks, Michael explained.

“Materials handling and movement within and between facilities is critical to the efficient functioning of all links of the food-related supply chain, but product movement can be a source of occupational injuries,” he said. “For example, manufacturers often use palletizers to aggregate individually packaged food products into a unit load before they can be transported using a pallet jack, forklift or other powered industrial truck.”

Michael, who is the Penn State Nationwide Insurance Professor of Safety and Health in the College of Agricultural Sciences, noted that the COVID-19 pandemic motivated his team to undertake the research. They were curious about how the added pressure on the food supply chain was affecting workers.

News reports in the first year of the pandemic gave the impression that our food supply chain was not keeping up with the new demands from the pandemic, he explained. It was clear most Americans had to stay home, and that changed the way that food had to be prepared, packaged and moved.

“Suddenly, we weren't eating out at restaurants, we were going to the grocery store or ordering online much more and buying food products that we hadn't purchased the same way before,” he said. “We suspected this put a lot of pressure on the workers in the food supply chain. And we wanted to try to document that, to highlight the increase in injuries during the first part of the pandemic when the food supply chain was under tremendous pressure.”

And significantly, Michael added, “we wanted to emphasize the importance of the blue-collar food industry workers and the sacrifices they make every day to get food from the farm to our tables.”

The researchers used a database maintained by the U.S. Occupational Safety and Health Administration to investigate all severe injuries in the six years from 2015 to 2020 in the food supply chain. Their results documented 1,084 severe injuries and 47 fatalities during the six-year period although the researchers noted that actual figures could be twice as high. Data indicated that 2020 saw a significant increase in severe injuries as compared to previous years.

In findings published this morning (Feb. 24) in the Journal of Safety Research, the researchers reported that fractures of the lower extremities were most prevalent, with the most frequent accident event type being transportation-related, such as pedestrian-vehicle incidents.

Large retailers that sell food along with many other products — such as Walmart, Sam’s Club and Costco — were not included in the research, Michael pointed out.

“We wanted to be very narrow with our definition of a grocery store or a food retailer, and those big, multi-faceted operations are not, strictly speaking, just grocery or food retailers, because food is just a part of their overall sales,” he said.

“It would not have been possible for us to determine which of their accidents and injuries were related to moving food products. If we had somehow been able to include their statistics, of course, the injury numbers would be considerably higher.”

Serap Gorucu, assistant professor of risk analysis, safety, and health of agricultural systems at the University of Florida, contributed to the research.

The research was funded in part by the Nationwide Insurance Endowment for Safety & Health.

---

JOURNAL

Journal of Safety Research

DOI

10.1016/j.jsr.2023.02.007 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Severe injuries from product movement in the U.S. food supply chain

How does a person’s ethnicity impact their risk of death?

Study analyzed mortality patterns among the three largest ethnic groups in the UK— Asian, Black and White— using data on nearly half a million UK Biobank participants.

Peer-Reviewed Publication

PLOS

 

IMAGE: MORTALITY view more 

CREDIT: LEE ET AL., 2022, PLOS GLOBAL PUBLIC HEALTH, CC-BY 4.0 (HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

In the UK, disparities in mortality risk factors exist between ethnic groups, with differences in overall mortality, top causes of mortality and individual mortality risk factors, according to a new study published this week in the open-access journal PLOS Global Public Health by I. King Jordan of Georgia Institute of Technology, US, and colleagues.

Despite the progress made in improving mortality rate, life expectancy, and disease survival outcomes in the last century, health disparities between various population groups persist and remain a major global health issue. Both environmental and genetic factors, with increasing evidence for interaction between environment and genetics through epigenetic mechanisms, have been cited as contributors of health disparities.

In the new study, the researchers analyzed data on 490,610 Asian, Black and White participants from the UK Biobank, a prospective study that enrolled 500,000 people in the UK aged 40 to 69 between 2006 and 2010. The UK Biobank includes data spanning physical measures, lifestyle, blood and urine biomarkers, imaging, genetic, and linked medical and death registry records.

Overall, the White ethnic group had a higher all-cause mortality rate than the Asian and Black groups. Moreover, Asian and Black females had lower risk of mortality than Asian and Black men, but that sex difference was absent among Whites. Certain causes of mortality were more common among the different ethnic groups: Asians had the highest mortality from ischemic heart disease, while Blacks had the highest mortality from COVID-19 and Whites had the highest mortality from cancers of respiratory/intrathoracic organs. In addition, some preexisting medical conditions and biomarkers showed specific associations with ethnicity and mortality. Mental health diagnoses, for instance, were a major risk factor for mortality for the Asian group, whereas parasitic diseases and C-reactive protein (CRP) serum levels were associated with higher mortality in the Black group.

“These results underscore the importance of population-specific studies that can help decompose health disparities and inform targeted interventions towards greater health equity,” the researchers concluded.

The authors add: “Despite a recent decrease in the overall burden of disease mortality, ethnic disparities in mortality persist for a number of diseases.  Our study of the United Kingdom Biobank revealed numerous blood biomarkers, environmental, and behavioral risk factors that explain ethnic disparities for all-cause mortality and disease-specific mortality for digestive system cancers, COVID-19, and coronary heart disease.”

 

#####

In your coverage please use this URL to provide access to the freely available article in PLOS Global Public Health: https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0001560

Citation: Lee KK, Norris ET, Rishishwar L, Conley AB, Mariño-Ramírez L, McDonald JF, et al. (2023) Ethnic disparities in mortality and group-specific risk factors in the UK Biobank. PLOS Glob Public Health 3(2): e0001560. https://doi.org/10.1371/journal.pgph.0001560

Author Countries: USA

Funding: The work was supported by the National Institutes of Health (NIH) Distinguished Scholars Program (DSP) (1ZIAMD000016 and 1ZIAMD000018 to LMR and the Division of Intramural Research (DIR) of the National Institute on Minority Health and Health Disparities (NIMHD) at NIH), the IHRC-Georgia Tech Applied Bioinformatics Laboratory (RF383 to KKL, ETN, LR, ABC, and IKJ), and the Ovarian Cancer Institute (Atlanta), Deborah Nash Endowment, and Northside Hospital Research Foundation to JFM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

---

JOURNAL

PLOS Global Public Health

DOI

10.1371/journal.pgph.0001560 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Ethnic disparities in mortality and group-specific risk factors in the UK Biobank

ARTICLE PUBLICATION DATE

23-Feb-2023

Gender dysphoria in young people is rising—and so is professional disagreement

Is there an evidence-based standard of care in the US?

Peer-Reviewed Publication

BMJ

More children and adolescents are identifying as transgender and offered medical treatment, especially in the US. But some providers and European authorities are urging caution because of a lack of strong evidence. 

In a new report from The BMJ Investigations Unit, Jennifer Block, investigations reporter, looks into the evidence base behind this surge in treatment.

More adolescents with no history of gender dysphoria are presenting at gender clinics. For example, a recent analysis of insurance claims found that nearly 18,000 US minors began taking puberty blockers or hormones from 2017 to 2021, the number rising each year.

Meanwhile, the number of US private clinics focused on providing hormones and surgeries have grown from just a few a decade ago to more than 100 today.

American medical professional groups are aligned in support of “gender affirming care” for gender dysphoria, which may include hormone treatment to suppress puberty and promote secondary sex characteristics, and surgical removal or augmentation of breasts, genitals, and other physical features.

Three organisations in particular have had a major role in shaping the US approach to gender dysphoria care: The World Professional Association for Transgender Health (WPATH), the American Academy of Pediatrics, and the Endocrine Society, all of which have guidelines or policies that support early medical treatment for gender dysphoria in young people.

These endorsements are often cited to suggest that medical treatment is both uncontroversial and backed by rigorous science, but governing bodies around the world have come to different conclusions regarding the safety and efficacy of certain treatments, notes Block. 

For example, Sweden’s National Board of Health and Welfare, which sets guidelines for care, determined earlier this year that the risks of puberty blockers and treatment with hormones “currently outweigh the possible benefits” for minors.

And NHS England, which is in the midst of an independent review of gender identity services, recently stated that there is “scarce and inconclusive evidence to support clinical decision-making” for minors with gender dysphoria, and that for most who present before puberty it will be a “transient phase,” requiring clinicians to focus on psychological support and to be “mindful” of the risks of even social transition 

Experts are also questioning the evidence underpinning these guidelines.

Professor Mark Helfand at Oregon Health and Science University identified several deficiencies in WPATH’s recommendations, such as lack of a grading system to indicate the quality of the evidence, while Professor Gordon Guyatt at McMaster University found “serious problems” with the Endocrine Society guidelines, including pairing strong recommendations with weak evidence.

Helfand explains that calling a recommendation ‘evidence-based’ should mean a treatment has not just been systematically studied, but that there was also a finding of high quality evidence supporting its use. 

Despite these concerns, WPATH recommends that youth have access to treatments following comprehensive assessment, stating “the emerging evidence base indicates a general improvement in the lives of transgender adolescents.”

Eli Coleman, lead author of WPATH’s Standards of Care and former director of the Institute for Sexual and Gender Health at the University of Minnesota, told The BMJ that WPATH’s new guidelines emphasise “careful assessment prior to any of these interventions” by clinicians who have appropriate training and competency to assure that minors have “the emotional and cognitive maturity to understand the risks and benefits.”

But without an objective diagnostic test, others remain concerned, pointing to examples of teenagers being “fast-tracked to medical intervention” with little or no mental health involvement. 

And in her interim report of a national review into services for young people with gender identity issues, Hilary Cass noted that some NHS staff reported feeling “under pressure to adopt an unquestioning affirmative approach and that this is at odds with the standard process of clinical assessment and diagnosis that they have been trained to undertake in all other clinical encounters.”

For Guyatt, claims of certainty represent both the success and failure of the evidence-based medicine movement. “When there’s been a rigorous systematic review of the evidence and the bottom line is ‘we don’t know,’” he says, then “anybody who then claims they do know is not being evidence based.”

---

DOI

10.1136/bmj.p382 

METHOD OF RESEARCH

News article

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Gender dysphoria in young people is rising—and so is professional disagreement

ARTICLE PUBLICATION DATE

23-Feb-2023

Scientists identify new mechanism of corrosion

Controlling one-dimensional wormhole corrosion could help advance power plant designs

Peer-Reviewed Publication

PENN STATE

 

IMAGE: MOLTEN SALT CORRODED A METAL BARRIER, APPEARING DISCONNECTED ON A SLICE VIEW OF THE DAMAGE (RIGHT). RESEARCHERS IMAGED THE CORROSION IN 3D AND RECONSTRUCTED THE PATH THE SALT TOOK THROUGH METAL (LEFT). view more 

CREDIT: YANG YANG/PENN STATE

UNIVERSITY PARK, Pa. — It started with a mystery: How did molten salt breach its metal container? Understanding the behavior of molten salt, a proposed coolant for next-generation nuclear reactors and fusion power, is a question of critical safety for advanced energy production. The multi-institutional research team, co-led by Penn State, initially imaged a cross-section of the sealed container, finding no clear pathway for the salt appearing on the outside. The researchers then used electron tomography, a 3D imaging technique, to reveal the tiniest of connected passages linking two sides of the solid container. That finding only led to more questions for the team investigating the strange phenomenon.   

They published the answers on Feb. 22 in Nature Communications. 

“Corrosion, a ubiquitous failure mode of materials, is traditionally measured in three dimensions or two dimensions, but those theories were not sufficient to explain the phenomenon in this case,” said co-corresponding author Yang Yang, assistant professor of engineering science and mechanics and of nuclear engineering at Penn State. He is also affiliated with the National Center for Electron Microscopy at Lawrence Berkeley National Laboratory, as well as the Materials Research Institute at Penn State. “We found that this penetrating corrosion was so localized, it only existed in one dimension — like a wormhole.” 

Wormholes on Earth, unlike the hypothetical astrophysical phenomenon, are typically bored by insects like worms and beetles. They dig into the ground, wood or fruits, leaving one hole behind as they excavate an unseen labyrinth. The worm may return to the surface through a new hole. From the surface, it looks like the worm disappears at one point in space and time and reappears at another. Electron tomography could reveal the hidden tunnels of the molten salt’s route on a microscopic scale, whose morphology looks very similar to the wormholes.

To interrogate how the molten salt “digs” through metal, Yang and the team developed new tools and analysis approaches. According to Yang, their findings not only uncover a new mechanism of corrosion morphology, but also point to the potential of intentionally designing such structures to enable more advanced materials. 

“Corrosion is often accelerated at specific sites due to various material defects and distinct local environments, but the detection, prediction and understanding of localized corrosion is extremely challenging,” said co-corresponding author Andrew M. Minor, professor of materials science and engineering at the University of California Berkeley and Lawrence Berkeley National Laboratory.

The team hypothesized that wormhole formation is linked to the exceptional concentration of vacancies — the empty sites that result from removing atoms — in the material. To prove this, the team combined 4D scanning transmission electron microscopy with theoretical calculations to identify the vacancies in the material. Together, this allowed the researchers to map vacancies in the atomic arrangement of the material at the nanometer scale. The resulting resolution is 10,000 times higher than conventional detection methods, Yang said. 

“Materials are not perfect,” said co-corresponding author Michael Short, associate professor of nuclear science and engineering at the Massachusetts Institute of Technology (MIT). “They have vacancies, and the vacancy concentration increases as the material is heated, is irradiated or, in our case, undergoes corrosion. Typical vacancy concentrations are much less than the one caused by molten salt, which aggregates and serve as the precursor of the wormhole.” 

Molten salt, which can be used as a reaction medium for materials synthesis, recycling solvent and more in addition to a nuclear reactor coolant, selectively removes atoms from the material during corrosion, forming the 1D wormholes along 2D defects, called grain boundaries, in the metal. The researchers found that molten salt filled the voids of various metal alloys in unique ways. 

“Only after we know how the salt infiltrates can we intentionally control or use it,” said co-first author Weiyue Zhou, postdoctoral associate at MIT. “This is crucial for the safety of many advanced engineering systems.”

Now that the researchers better understand how the molten salt traverses specific metals — and how it changes depending on the salt and metal types — they said they hope to apply that physics to better predict the failure of materials and design more resistant materials. 

“As a next step, we want to understand how this process evolves as a function of time and how we can capture the phenomenon with simulation to help understand the mechanisms,” said co-author Mia Jin, assistant professor of nuclear engineering at Penn State. “Once modeling and experiments can go hand-in-hand, it can be more efficient to learn how to make new materials to suppress this phenomenon when undesired and utilize it otherwise.”

Other contributors include co-authors Jim Ciston, M.C. Scott, Sheng Yin, Qin Yu, Robert O. Ritchie and Mark Asta, Lawrence Berkeley National Laboratory; co-authors Mingda Li and Ju Li, MIT; Sarah Y. Wang, Ya-Qian Zhang and Steven E. Zeltmann, University of California, Berkeley; Matthew J. Olszta and Daniel K. Schreiber, Pacific Northwest National Laboratory; and John R. Scully, University of Virginia. Minor, Scott, Ritchie and Asta are also affiliated with the University of California, Berkeley. 

This work was primarily supported by FUTURE (Fundamental Understanding of Transport Under Reactor Extremes), an Energy Frontier Research Center funded by the Department of Energy, Office of Science, Basic Energy Sciences.   

Researchers found that corrosion mechanisms differ in dimensions from three to two to one. In 1D, the corrosion partially runs along the grain boundaries of the metal material.

Molten salt penetrates various metal alloys in different patterns; oxide growth can form similar 1D morphology. From top left, clockwise: stainless steel corroded in salt, iron-nickel-chromium alloy corroded in salt, chromium-manganese-iron-cobalt-nickel alloy oxidized in air and nickel-aluminum alloy oxidized in water. All the morphologies appear similar, covering partial grain boundaries.

CREDIT

Yang Yang/Penn State

JOURNAL

Nature Communications

DOI

10.1038/s41467-023-36588-9 

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

One dimensional wormhole corrosion in metals

ARTICLE PUBLICATION DATE

22-Feb-2023

Plastic upcycling to close the carbon cycle

A new PNNL-developed process produces fuel quickly at mild temperature, with few by-products

Peer-Reviewed Publication

DOE/PACIFIC NORTHWEST NATIONAL LABORATORY

 

IMAGE: A NEW METHOD TO CONVERT LOW-DENSITY PLASTIC WASTE TO FUEL AND RAW MATERIALS PROMISES TO HELP CLOSE THE CARBON CYCLE. view more 

CREDIT: (ART BY MELANIE HESS-ROBINSON | PACIFIC NORTHWEST NATIONAL LABORATORY)

RICHLAND, Wash.—There’s a lot of potentially useful raw materials bound up in used face masks, grocery bags and food wrap. But it has been much cheaper to keep making more of these single-use plastics than to recover and recycle them.

Now, an international research team led by the Department of Energy’s Pacific Northwest National Laboratory has cracked the code that stymied previous attempts to break down these persistent plastics. They reported their discovery in today’s issue of Science.

Low temperature and reaction control

Typically, recycling plastics requires ‘cracking’ or splitting apart the tough and stable bonds that also make them so persistent in the environment. This cracking step requires high temperatures, making it expensive and energy intensive.

The novelty here is combining the cracking step with a second reaction step that immediately completes the conversion to a liquid gasoline-like fuel without unwanted byproducts. The second reaction step deploys what are known as alkylation catalysts. These catalysts provide a chemical reaction currently deployed by the petroleum industry to improve the octane rating of gasoline.

Crucially in the current study, the alkylation reaction immediately follows the cracking step in a single reaction vessel, near room temperature (70 degrees C/158 degrees F).

“Cracking just to break the bonds results in them forming another one in an uncontrolled way, and that's a problem in other approaches,” said  Oliver Y. Gutiérrez, a study author and chemist at PNNL. “The secret formula here is that when you break a bond in our system, you immediately make another one in a targeted way that gives you the end product you want. That is also the secret that enables this conversion at low temperature.”

In their study, the research team, co-led by scientists from the Technical University of Munich, Germany, pointed to separate, recent developments by the petroleum industry to commercialize the second part of the process reported here for crude oil processing.

“The fact that industry has successfully deployed these emerging alkylation catalysts demonstrates their stable, robust nature,” said Johannes Lercher, a senior author of the study, director of PNNL’s Institute for Integrated Catalysis, and professor of chemistry at TUM. “This study points to a practical new solution to close the carbon cycle for waste plastic that is closer to implementation than many others being proposed.”

In their study, the researchers note a limitation on their findings. The process works for low-density polyethylene products (LDPE, plastic resin code #4), such as plastic films and squeezable bottles, and polypropylene products (PP, plastic resin code #5) that are not typically collected in curb-side recycling programs in the United States. High-density polyethylene (HPDE, plastic resin code #2) would require a pretreatment to allow the catalyst access to the bonds it needs to break.

Seeing waste plastic as future fuel and new products

Petroleum-based plastic waste is an untapped resource that can serve as the starting material for useful durable materials and for fuels. More than half of the 360 million tons of plastics produced globally each year are the plastics targeted in this study. But looking at a mountain of plastic and seeing its value requires an innovator’s mindset, a chemist’s ingenuity, and a realist’s understanding of the economics involved. These scientists are trying to change the dynamic by applying their expertise in efficiently breaking chemical bonds.

“To solve the problem of persistent waste plastic, we need to reach a critical point where it makes more sense to collect it and return it to use than to treat it as disposable,” said Lercher. “We’ve shown here that we can make that conversion quickly, at mild conditions, which provides one of the incentives to move forward to that tipping point.”

This research study, published Feb. 24, 2023, was supported by the Department of Energy Office of Science.

---

JOURNAL

Science

DOI

10.1126/science.ade7485 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Low-temperature upcycling of polyolefins into liquid alkanes via tandem cracking-alkylation

ARTICLE PUBLICATION DATE

24-Feb-2023