It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, April 19, 2022
Praising essential workers — nurses, grocery workers, corrections officers — is not just a good thing, it’s critical to their recovery from burnout
Essential workers who feel public praise recover from burnout; those less visible workers (like corrections officers) who don't feel that praise don't recover well
Remember when all those Twitter and Instagram posts thanking front-line workers blew up after the COVID pandemic hit? Turns out those were a big deal to essential workers.
Unfortunately, not all the essential workers felt the love, and that had major negative impacts.
A new study from Brigham Young University, University of Arizona, Rider University and New York University finds essential workers who receive public praise are energized and recover in healthy ways from the stress of their jobs, while those who don’t receive that praise experience negative emotions and are more likely to drink, smoke or overeat to recover from work.
“There are a lot of people that work behind the scenes, and we don’t see them, but they do need our public gratitude,” said study author Taeya Howell, an assistant professor in BYU's Marriott School of Business. “One of the main drivers behind doing the project was to understand what public gratitude does for essential workers while also calling attention to essential workers who are less visible.”
According to the study, published this month in Social Psychological and Personality Sciences, a significant number of essential workers in less visible fields — corrections officers, sanitation workers, truck drivers — felt the public had expressed no gratitude toward them at all. The research included two main studies: a survey of 186 corrections officers in hard-hit New England states during May/June 2020 and a second survey of 376 other essential workers who had seen social media posts praising their work or the work of other essential workers.
Quotes from two essential workers paint a clear picture of the disparity between those receiving the public praise (think nurses, doctors and grocery store workers) and those who did not.
“We’re doing three times the amount of work and feel more unappreciated than before this virus,” said one corrections officer. “Sometimes I question why I’m still an officer.” Contrast that with what one nurse reported in the media as saying: “From the patients, from the families, from management, from random people on the street… They stopped to say ‘Thank you,’ and it just re-energizes you.”
The study found that despite their essentiality, many workers who are less visible to the public received little appreciation for their efforts. For example, a pilot study by the same authors found that only 3% of those surveyed thought of corrections officers when asked to list those considered essential during the pandemic. Said one corrections officer interviewed in the study: “This job is thankless… we believe that people feel that our lives are not as valuable as other first responders.”
However, those who felt seen and appreciated were more likely to engage in healthy activities associated with a positive mental state, like exercising, meditating and spending time outdoors.
Authors say the study demonstrates the importance of public gratitude for essential workers’ long-term health, well-being and, indirectly, for the quality of their work. They also said the findings are also applicable beyond COVID-19, to other future health crises and disaster situations where essential workers do critical work, as well as to routinely stressful events.
“The general public needs to be more cognizant of the fact that showing gratitude to only some essential workers (but not others) can have detrimental effects on those who don’t receive gratitude,” said study author Hee Young Kim, associate professor of management at Rider University.
Fellow study author Sarah Doyle said people should remember that expressions of gratitude are essentially free, and yet they can have a substantial impact on the well-being of essential personnel.
“From an organizational perspective, this is a pretty powerful insight because companies spend a lot of money on other programs or initiatives that are intended to improve well-being of these workers, and yet may not be positively impacting these workers in the same way that felt gratitude does,” said Doyle, assistant professor of management and organizations at the University of Arizona’s Eller College of Management.
Dr. Michael Bizzarro of Penn Medicine Behavioral Health, Nathan Pettit, an associate professor at NYU, and Sijun Kim from the University of Arizona were also co-authors on the study.
IMAGE: INHALED FINE PARTICULATE MATTER (SHOWN HERE IN RED) PULLS STRINGS OF COLLAGEN TO DISTURB THE IMMUNE DEFENCE IN MICE WITH LUNG CANCER CELLS. THIS ACTIVITY DELAYS THE MOVEMENT OF CYTOTOXIC T-CELLS (PURPLE) AS THEY MIGRATE TOWARDS THE CANCER CELLS (GREEN) TO DESTROY THEM.view more
CREDIT: WANG ET AL. (CC BY 4.0)
Scientists have identified a mechanism that explains how fine air pollution particles might cause lung cancer, according to a study published today in eLife.
The findings could lead to new approaches for preventing or treating the initial lung changes that lead to the disease.
Tiny, inhalable fine particulate matter (FPM) found in air pollutants has been recognised as a Group 1 carcinogen and a substantial threat to global health. However, the cancer-causing mechanism of FPM remains unclear.
“Despite its potential to cause mutations, recent research suggests that FPM does not directly promote – and may even inhibit – the growth of lung cancer cells,” explains first author Zhenzhen Wang, an associate researcher at Nanjing University (NJU), Nanjing, China, who carried out the study between labs at NJU and the University of Macau where she was sponsored by a University of Macau Fellowship. “This suggests that FPM might lead to cancer through indirect means that support tumour growth. For example, some studies suggest FPM can prevent immune cells from moving to where they are needed.”
To explore this possibility, Wang and the team collected FPM from seven locations in China and studied its effects on the main immune cells that defend against tumour growth – called cytotoxic T-cells (CTLs). In mice administered with lung cancer cells that were not exposed to FPM, CTLs were recruited to the lung to destroy the tumour cells. By contrast, in the mice whose lungs were exposed to FPM, the infiltration of CTLs was delayed – potentially allowing the tumour cells to establish in lung tissue.
To investigate why the CTLs did not enter the lung as quickly in the FPM-exposed lungs, the team studied both the CTLs themselves and the lung tissue structure. They found that CTLs exposed to FPM still retained their migratory ability, but that FPM exposure dramatically compressed the lung tissue structure and the spaces that immune cells move between. There were also much higher levels of collagen – a protein that provides biomechanical support for cells and tissues. When the team studied the movement of CTLs in the mice, in lung tissue exposed to FPM, CTLs struggled to move, whereas those in the untreated tissue were able to move freely.
Further analysis of the tissue showed that the structural changes were caused by increases in a collagen subtype called collagen IV, but the team still did not know how FPM triggered this. They found the answer when they looked more closely at the structural changes to collagen IV and the enzyme responsible for making them – called peroxidasin. This enzyme drives a specific type of cross-linking that exposure to FPM was found to cause and aggravate in the lung tissue.
“The most surprising find was the mechanism by which this process occurred,” Wang says. “The peroxidasin enzyme stuck to the FPM in the lung, which increased its activity. Taken together, this means that wherever FPM lands in the lung, increased peroxidasin activity leads to structural changes in the lung tissue that can keep immune cells out and away from growing tumour cells.”
“Our study reveals a completely new mechanism by which inhaled fine particles promote lung tumour development,” concludes senior author Lei Dong, Professor at the School of Life Sciences, Nanjing University. “We provide direct evidence that proteins that stick to fine particulate matter can cause a significant and adverse effect, giving rise to pathogenic activity. Our discovery that peroxidasin is the mediator of this effect in lung tissue identifies it as a specific and unexpected target for preventing lung disease caused by air pollution.”
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NATIONAL CENTER FOR ATMOSPHERIC RESEARCH/UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH
Increasingly large and intense wildfires in the Pacific Northwest are altering the seasonal pattern of air pollution and causing a spike in unhealthy pollutants in August, new research finds. The smoke is undermining clean air gains, posing potential risks to the health of millions of people, according to the study.
The research, led by scientists at the National Center for Atmospheric Research (NCAR), found that levels of carbon monoxide — a gas that indicates the presence of other air pollutants — have increased sharply as wildfires spread in August. Carbon monoxide levels are normally lower in the summer because of chemical reactions in the atmosphere related to changes in sunlight, and the finding that their levels have jumped indicates the extent of the smoke’s impacts.
“Wildfire emissions have increased so substantially that they’re changing the annual pattern of air quality across North America,” said NCAR scientist Rebecca Buchholz, the lead author. “It’s quite clear that there is a new peak of air pollution in August that didn’t used to exist.”
Although carbon monoxide generally is not a significant health concern outdoors, the gas indicates the presence of more harmful pollutants, including aerosols (airborne particulates) and ground-level ozone that tends to form on hot summer days.
The research team used satellite-based observations of atmospheric chemistry and global inventories of fires to track wildfire emissions during most of the past two decades, as well as computer modeling to analyze the potential impacts of the smoke. They focused on three North American regions: the Pacific Northwest, the central United States, and the Northeast.
Buchholz said the findings were particularly striking because carbon monoxide levels have been otherwise decreasing, both globally and across North America, due to improvements in pollution-control technologies.
The study was published this week in Nature Communications. The research was funded in part by the U.S. National Science Foundation, NCAR’s sponsor. The paper was co-authored by researchers from the University of Colorado, Boulder; Columbia University; NASA; Tsinghua University; and Colorado State University.
Increasing impacts on air pollution
Wildfires have been increasing in the Pacific Northwest and other regions of North America, due to a combination of climate change, increased development, and land use policies. The fires are becoming a larger factor in air pollution, especially as emissions from human activities are diminishing because of more efficient combustion processes in motor vehicles and industrial facilities.
To analyze the impacts of fires, Buchholz and her collaborators used data from two instruments on the NASA Terra satellite: MOPITT (Measurements of Pollution in the Troposphere), which has tracked carbon monoxide continually since 2002; and MODIS (Moderate Resolution Imaging Spectrometer), which detects fires and provides information on aerosols. They also studied four inventories of wildfire emissions, which rely on MODIS data.
The scientists focused on the period from 2002, the beginning of a consistent and long-term record of MOPPIT data, to 2018, the last year for which complete observations were available at the time when they began their study.
The results showed an increase in carbon monoxide levels across North America in August, which corresponded with the peak burning season of the Pacific Northwest. The trend was especially pronounced from 2012 to 2018, when the Pacific Northwest fire season became much more active, according to the emissions inventories. Data from the MODIS instrument revealed that aerosols also showed an upward trend in August.
To determine whether the higher pollution levels were caused by the fires, the scientists eliminated other potential emission sources. They found that carbon monoxide levels upwind of the Pacific Northwest, over the Pacific Ocean, were much lower in August — a sign that the pollution was not blowing in from Asia. They also found that fire season in the central U.S. and the Northeast did not coincide with the August increase in pollution, which meant that local fires in those regions were not responsible. In addition, they studied a pair of fossil fuel emission inventories, which showed that carbon monoxide emissions from human activities did not increase in any of the three study regions from 2012 to 2018.
“Multiple lines of evidence point to the worsening wildfires in the Pacific Northwest as the cause of degraded air quality,” Buchholz said. “It’s particularly unfortunate that these fires are undermining the gains that society has made in reducing pollution overall.”
Risks to human health
The findings have implications for human health because wildfire smoke has been linked to significant respiratory problems, and it may also affect the cardiovascular system and worsen pregnancy outcomes.
Buchholz and her co-authors used an NCAR-based computer model, the Community Atmosphere Model with a chemistry component, to simulate the movement of emissions from the Pacific Northwest fires and their impact on carbon monoxide, ozone, and fine particulate matter. They ran the simulations on the Cheyenne supercomputer at the NCAR-Wyoming Supercomputing Center. The results showed the pollutants could affect more than 130 million people, including about 34 million in the Pacific Northwest, 23 million in the Central U.S., and 72 million in the Northeast.
Although the study did not delve deeply into the health implications of the emissions, the authors looked at respiratory death rates in Colorado for the month of August from 2002 to 2011, compared with the same month in 2012 to 2018. They chose Colorado, located in the central U.S. region of the study, because respiratory death rates in the state were readily obtainable.
They found that Colorado respiratory deaths in August increased significantly during the 2012-2018 period, when fires in the Pacific Northwest — but not in Colorado — produced more emissions in August.
“It’s clear that more research is needed into the health implications of all this smoke,” Buchholz said. “We may already be seeing the consequences of these fires on the health of residents who live hundreds or even thousands of miles downwind.”
This material is based upon work supported by the National Center for Atmospheric Research, a major facility sponsored by the National Science Foundation and managed by the University Corporation for Atmospheric Research. Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.
About the article
Title: New seasonal pattern of pollution emerges from changing North American wildfires Authors: Rebecca R. Buchholz, Mijeong Park, Helen M. Worden, Wenfu Tang, David P. Edwards, Benjamin Gaubert, Merritt Deeter, Thomas Sullivan, Muye Ru, Mian Chin, Robert C. Levy, Bo Zheng, and Sheryl Magzamen Journal:Nature Communications
ITHACA, N.Y. – A Cornell University study describes a breakthrough in the quest to improve photosynthesis in certain crops, a step toward adapting plants to rapid climate changes and increasing yields to feed a projected 9 billion people by 2050.
The authors developed a computational technique to predict favorable gene sequences that make Rubisco, a key plant enzyme for photosynthesis. The technique allowed the scientists to identify promising candidate enzymes that could be engineered into modern crops and, ultimately, make photosynthesis more efficient and increase crop yields.
Their method relied on evolutionary history, where the researchers predicted Rubisco genes from 20-30 million years ago, when Earth’s carbon dioxide (CO2) levels were higher than they are today and the Rubisco enzymes in plants were adapted to those levels.
By resurrecting ancient Rubisco, early results show promise for developing faster, more efficient Rubisco enzymes to incorporate into crops and help them adapt to hot, dry future conditions, as human activities are increasing heat-trapping CO2 gas concentrations in Earth’s atmosphere.
The study describes predictions of 98 Rubisco enzymes at key moments in the evolutionary history of plants in the Solanaceae family, which include tomato, pepper, potato, eggplant and tobacco. Researchers use tobacco as the experimental model for their studies of Rubisco.
“We were able to identify predicted ancestral enzymes that do have superior qualities compared to current-day enzymes,” Hanson said. Lin developed the new technique for identifying predicted ancient Rubisco enzymes.
Scientists have known that they can increase crop yields by accelerating photosynthesis, where plants convert CO2, water and light into oxygen and sugars that plants use for energy and for building new tissues.
For many years, researchers have focused on Rubisco, a slow enzyme that pulls (or fixes) carbon from CO2 to create sugars. Aside from being slow, Rubisco also sometimes catalyzes a reaction with oxygen in the air; by so doing, it creates a toxic byproduct, wastes energy and makes photosynthesis inefficient.
Hanson’s lab had previously tried to use Rubisco from cyanobacteria (blue-green algae), which is faster but also reacts readily with oxygen, forcing the researchers to try to create micro-compartments to protect the enzyme from oxygen, with mixed results. Other researchers have tried to engineer more optimal Rubisco by making changes in the enzyme’s amino acids, though little was known about which changes would lead to desired results.
In this study, Lin reconstructed a phylogeny – a tree-like diagram showing evolutionary relatedness among groups of organisms – of Rubisco, using Solanaceae plants.
“By getting a lot of [genetic] sequences of Rubisco in existing plants, a phylogenetic tree could be constructed to figure out which Rubiscos likely existed 20 to 30 million years ago,” Hanson said.
The advantage of identifying potential ancient Rubisco sequences is that carbon dioxide levels were possibly as high as 500 to 800 parts per million (ppm) in the atmosphere 25 million to 50 million years ago. Today, heat-trapping CO2 levels are rising sharply due to many human activities, with current measurements at around 420 ppm, after staying relatively constant under 300 ppm for hundreds of millennia until the 1950s.
Lin, Hanson and colleagues then used an experimental system developed for tobacco in Hanson’s lab, and described in a 2020 Nature Plants paper, which employs E. coli bacteria to test in a single day the efficacy of different versions of Rubisco. Similar tests done in plants take months to verify.
The team found that ancient Rubisco enzymes predicted from modern-day Solanaceae plants showed real promise for being more efficient.
“For the next step, we want to replace the genes for the existing Rubisco enzyme in tobacco with these ancestral sequences using CRISPR [gene-editing] technology, and then measure how it affects the production of biomass,” Hanson said. “We certainly hope that our experiments will show that by adapting Rubisco to present day conditions, we will have plants that will give greater yields.”
If their method proves successful, these efficient Rubisco sequences could be transferred into crops such as tomatoes, as well as those from other plant families, such as soybeans and rice.
The study was funded by the U.S. Department of Energy.
In percentage terms, Asian Americans are the fastest-growing U.S. racial group for the past three censuses, yet data aggregation obscure distinctions within subgroups of the more than 24 million Asians living in the United States. The JNCI commentary illustrates the harmful impacts this is having on Asian American communities.
Chen said the neglect of Asian American cancer inequities stems from multiple factors. They include historical prejudices against Asian Americans and the myth of Asian Americans as the model healthy minority, compounded by language and cultural barriers as well as racism.
“Asian Americans are unique as the first U.S. population to experience cancer as the leading cause of death,” said Chen. “Bigotry against Asian Americans, pervasive since the 19th century, but especially during the COVID-19 pandemic, is only exacerbating the cancer disparities that are costing Asian Americans their lives.”
High rates of certain cancer in Asian Americans
The authors cite a disproportionate rate of certain cancers affecting Asian Americans including:
Cancers due to infectious origin such as the human papillomavirus. For example, Vietnamese American women experience the highest U.S rates of cervical cancer.
High rates of liver cancer caused by chronic hepatitis B virus (HBV) infection rates in Asian and Southeast Asian Americans, including Hmong Americans.
Nasopharyngeal cancers, occurring in the upper part of the throat behind the nose, affecting Chinese Americans at high rates.
Stomach cancers, which have the highest rates among Korean Americans.
Lung cancer among never-smokers that disproportionately affects Asian American women at a rate of more than twice that of non-Hispanic white women.
The authors note an “infinitesimal proportion” of the National Institutes of Health (NIH) budget funded Asian American research even though the population is experiencing the highest percentage increases of any U.S. racial population for the past three decades. Between 1992 and 2018, only 0.17% of the total budget of the NIH funded research on Asian Americans. A portfolio analysis of grants funded by the National Cancer Institute’s Division of Cancer Control and Population Sciences showed a very limited number of studies focused on Asian Americans, with none at the time addressing the causes of cancer.
Asian Americans are also underrepresented in clinical trials. According to the commentary, only 1% of clinical trials emphasize racial and ethnic minority participation as a primary focus. Only 5 such trials focus on Asian Americans as compared with 83 for African Americans and 32 for Hispanics.
“Classifying Black Americans and Hispanic Americans as underrepresented minorities in clinical trials is helpful, but it is regrettable that our national policy excludes designating Asian Americans as underrepresented minorities, as documented by data in this commentary,” said Chen. “There is a myth that Asian Americans don’t get cancer, but that is far from the truth.”
What needs to happen to equalize cancer inequities
To rectify inequities, the authors recommend a call to action:
Disaggregate data for Asian American subgroups (Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippines, Thailand, and Vietnam). The commentary calls for a separate focus on Native Hawaiians and other Pacific Islanders.
Assess the impact of lived experiences and historical trauma. The authors state that culturally competent oncology care is required to improve access to health insurance/health care. They assert it is also needed to address language and cultural barriers that prevent Asian Americans from getting the medical help they need.
Listen to community voices. Rich diversity and unique experiences within Asian American communities are best understood and appreciated by listening to and partnering with patients and community advocates. Research must ensure community representation, buy-in and engagement.
“It is also important to focus on the impact of racism on cancer disparities and prioritize funding resources. Otherwise, we will not take the necessary steps forward for achieving health equity for Asian Americans,” Chen added.
In percentage terms, Asian Americans are the fastest-growing U.S. racial group for the past three censuses, yet data aggregation obscure distinctions within subgroups of the more than 24 million Asians living in the United States. The JNCI commentary illustrates the harmful impacts this is having on Asian American communities.
Chen said the neglect of Asian American cancer inequities stems from multiple factors. They include historical prejudices against Asian Americans and the myth of Asian Americans as the model healthy minority, compounded by language and cultural barriers as well as racism.
“Asian Americans are unique as the first U.S. population to experience cancer as the leading cause of death,” said Chen. “Bigotry against Asian Americans, pervasive since the 19th century, but especially during the COVID-19 pandemic, is only exacerbating the cancer disparities that are costing Asian Americans their lives.”
High rates of certain cancer in Asian Americans
The authors cite a disproportionate rate of certain cancers affecting Asian Americans including:
Cancers due to infectious origin such as the human papillomavirus. For example, Vietnamese American women experience the highest U.S rates of cervical cancer.
High rates of liver cancer caused by chronic hepatitis B virus (HBV) infection rates in Asian and Southeast Asian Americans, including Hmong Americans.
Nasopharyngeal cancers, occurring in the upper part of the throat behind the nose, affecting Chinese Americans at high rates.
Stomach cancers, which have the highest rates among Korean Americans.
Lung cancer among never-smokers that disproportionately affects Asian American women at a rate of more than twice that of non-Hispanic white women.
The authors note an “infinitesimal proportion” of the National Institutes of Health (NIH) budget funded Asian American research even though the population is experiencing the highest percentage increases of any U.S. racial population for the past three decades. Between 1992 and 2018, only 0.17% of the total budget of the NIH funded research on Asian Americans. A portfolio analysis of grants funded by the National Cancer Institute’s Division of Cancer Control and Population Sciences showed a very limited number of studies focused on Asian Americans, with none at the time addressing the causes of cancer.
Asian Americans are also underrepresented in clinical trials. According to the commentary, only 1% of clinical trials emphasize racial and ethnic minority participation as a primary focus. Only 5 such trials focus on Asian Americans as compared with 83 for African Americans and 32 for Hispanics.
“Classifying Black Americans and Hispanic Americans as underrepresented minorities in clinical trials is helpful, but it is regrettable that our national policy excludes designating Asian Americans as underrepresented minorities, as documented by data in this commentary,” said Chen. “There is a myth that Asian Americans don’t get cancer, but that is far from the truth.”
What needs to happen to equalize cancer inequities
To rectify inequities, the authors recommend a call to action:
Disaggregate data for Asian American subgroups (Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippines, Thailand, and Vietnam). The commentary calls for a separate focus on Native Hawaiians and other Pacific Islanders.
Assess the impact of lived experiences and historical trauma. The authors state that culturally competent oncology care is required to improve access to health insurance/health care. They assert it is also needed to address language and cultural barriers that prevent Asian Americans from getting the medical help they need.
Listen to community voices. Rich diversity and unique experiences within Asian American communities are best understood and appreciated by listening to and partnering with patients and community advocates. Research must ensure community representation, buy-in and engagement.
“It is also important to focus on the impact of racism on cancer disparities and prioritize funding resources. Otherwise, we will not take the necessary steps forward for achieving health equity for Asian Americans,” Chen added.
Many of the resources used to make batteries, such as lithium and pure graphite, are in limited supply or can potentially harm the environment after being disposed of. So, researchers are investigating ways to make batteries last longer, recover compounds from spent batteries or even incorporate alternative components. Below are some recent papers published in ACS journals that report insights into more sustainable technologies and materials to produce the next generation of batteries. Reporters can request free access to these papers by emailing newsroom@acs.org.
“Self-Oxygenated Blood Protein-Embedded Nanotube Catalysts for Longer Cyclable Lithium Oxygen-Breathing Batteries” ACS Sustainable Chemistry & Engineering March 23, 2022 Lithium-oxygen, or Li-O2, batteries are candidates for high-capacity, rechargeable energy-storage devices. But as they’re discharged, solid lithium peroxide builds up, and eventually, the system can’t be recharged. Now, researchers demonstrate that hemoglobin proteins — acquired from cow’s blood and embedded inside carbon nanotubes — catalyze the complete removal of these solids during charging, thereby helping extend the rechargeability of this type of battery.
“Alkaline Roasting Approach to Reclaiming Lithium and Graphite from Spent Lithium-Ion Batteries” ACS Sustainable Chemistry & Engineering March 21, 2022 Here, researchers recycled high-purity, high-performing graphite and lithium from dead lithium-ion battery anodes (negative electrodes) without generating harmful waste. They heated spent graphite with sodium hydroxide and then rinsed out most of the impurities, including newly formed lithium hydroxides and salts, with water. Both lithium and sodium hydroxide can be reclaimed from the wastewater, reducing the process’s waste and increasing its profitability.
“Sustainable Nitrogen Self-Doped Carbon Nanofibers from Biomass Chitin as Anodes for High-Performance Lithium-Ion Batteries” Energy & Fuels March 16, 2022 In this paper, researchers charred chitin — the main stuff in shrimp, lobster and crab shells — and show that it can be a naturally abundant replacement for graphite in the anode of a rechargeable lithium-ion battery. The resulting coin battery could be drained and recharged repeatedly without compromising the high capacity of its full charge. Charred chitin is a renewable source material for successfully generating high-performing and cost-effective lithium-ion batteries, the researchers say.
“Bimetallic Selenide Decorated Nanoreactor Synergizing Confinement and Electrocatalysis of Se Species for 3D-Printed High-Loading K–Se Batteries” ACS Nano Feb. 3, 2022 Potassium-selenium, or K-Se, batteries are considered promising for rechargeable energy storage because they’re produced from low-cost, abundant resources. But current versions lose their energy storage capacity very quickly. Here, researchers combined selenium, cobalt and nickel (Se/CoNiSe2) into spherical nanoreactors and 3D printed them into the cathode (positive electrode) of a button battery. The additional metals significantly lengthen the K-Se battery’s lifetime and make the system feasible for commercialization.
The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.
When you twist open an Oreo cookie to get to the creamy center, you’re mimicking a standard test in rheology — the study of how a non-Newtonian material flows when twisted, pressed, or otherwise stressed. MIT engineers have now subjected the sandwich cookie to rigorous materials tests to get to the center of a tantalizing question: Why does the cookie’s cream stick to just one wafer when twisted apart?
“There’s the fascinating problem of trying to get the cream to distribute evenly between the two wafers, which turns out to be really hard,” says Max Fan, an undergraduate in MIT’s Department of Mechanical Engineering.
In pursuit of an answer, the team subjected cookies to standard rheology tests in the lab and found that no matter the flavor or amount of stuffing, the cream at the center of an Oreo almost always sticks to one wafer when twisted open. Only for older boxes of cookies does the cream sometimes separate more evenly between both wafers.
The researchers also measured the torque required to twist open an Oreo, and found it to be similar to the torque required to turn a doorknob and about 1/10th what’s needed to twist open a bottlecap. The cream’s failure stress — i.e. the force per area required to get the cream to flow, or deform — is twice that of cream cheese and peanut butter, and about the same magnitude as mozzarella cheese. Judging from the cream’s response to stress, the team classifies its texture as “mushy,” rather than brittle, tough, or rubbery.
So, why does the cookie’s cream glom to one side rather than splitting evenly between both? The manufacturing process may be to blame.
“Videos of the manufacturing process show that they put the first wafer down, then dispense a ball of cream onto that wafer before putting the second wafer on top,” says Crystal Owens, an MIT mechanical engineering PhD candidate who studies the properties of complex fluids. “Apparently that little time delay may make the cream stick better to the first wafer.”
The team’s study isn’t simply a sweet diversion from bread-and-butter research; it’s also an opportunity to make the science of rheology accessible to others. To that end, the researchers have designed a 3D-printable “Oreometer” — a simple device that firmly grasps an Oreo cookie and uses pennies and rubber bands to control the twisting force that progressively twists the cookie open. Instructions for the tabletop device can be found here.
The new study, “On Oreology, the fracture and flow of ‘milk’s favorite cookie,’” appears today in Kitchen Flows, a special issue of the journal Physics of Fluids. It was conceived of early in the Covid-19 pandemic, when many scientists’ labs were closed or difficult to access. In addition to Owens and Fan, co-authors are mechanical engineering professors Gareth McKinley and A. John Hart.
Confection connection
A standard test in rheology places a fluid, slurry, or other flowable material onto the base of an instrument known as a rheometer. A parallel plate above the base can be lowered onto the test material. The plate is then twisted as sensors track the applied rotation and torque.
Owens, who regularly uses a laboratory rheometer to test fluid materials such as 3D-printable inks, couldn’t help noting a similarity with sandwich cookies. As she writes in the new study:
“Scientifically, sandwich cookies present a paradigmatic model of parallel plate rheometry in which a fluid sample, the cream, is held between two parallel plates, the wafers. When the wafers are counter-rotated, the cream deforms, flows, and ultimately fractures, leading to separation of the cookie into two pieces.”
While Oreo cream may not appear to possess fluid-like properties, it is considered a “yield stress fluid” — a soft solid when unperturbed that can start to flow under enough stress, the way toothpaste, frosting, certain cosmetics, and concrete do.
Curious as to whether others had explored the connection between Oreos and rheology, Owens found mention of a 2016 Princeton University study in which physicists first reported that indeed, when twisting Oreos by hand, the cream almost always came off on one wafer.
“We wanted to build on this to see what actually causes this effect and if we could control it if we mounted the Oreos carefully onto our rheometer,” she says.
Cookie twist
In an experiment that they would repeat for multiple cookies of various fillings and flavors, the researchers glued an Oreo to both the top and bottom plates of a rheometer and applied varying degrees of torque and angular rotation, noting the values that successfully twisted each cookie apart. They plugged the measurements into equations to calculate the cream’s viscoelasticity, or flowability. For each experiment, they also noted the cream’s “post-mortem distribution,” or where the cream ended up after twisting open.
In all, the team went through about 20 boxes of Oreos, including regular, Double Stuf, and Mega Stuf levels of filling, and regular, dark chocolate, and “golden” wafer flavors. Surprisingly, they found that no matter the amount of cream filling or flavor, the cream almost always separated onto one wafer.
“We had expected an effect based on size,” Owens says. “If there was more cream between layers, it should be easier to deform. But that’s not actually the case.”
Curiously, when they mapped each cookie’s result to its original position in the box, they noticed the cream tended to stick to the inward-facing wafer: Cookies on the left side of the box twisted such that the cream ended up on the right wafer, whereas cookies on the right side separated with cream mostly on the left wafer. They suspect this box distribution may be a result of post-manufacturing environmental effects, such as heating or jostling that may cause cream to peel slightly away from the outer wafers, even before twisting.
The understanding gained from the properties of Oreo cream could potentially be applied to the design of other complex fluid materials.
“My 3D printing fluids are in the same class of materials as Oreo cream,” she says. “So, this new understanding can help me better design ink when I’m trying to print flexible electronics from a slurry of carbon nanotubes, because they deform in almost exactly the same way.”
As for the cookie itself, she suggests that if the inside of Oreo wafers were more textured, the cream might grip better onto both sides and split more evenly when twisted.
“As they are now, we found there’s no trick to twisting that would split the cream evenly,” Owens concludes.
This research was supported, in part, by the MIT UROP program and by the National Defense Science and Engineering Graduate Fellowship Program.
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Written by Jennifer Chu, MIT News Office
Paper: “On Oreology, the fracture and flow of ‘milk’s favorite cookie’”
IMAGE: THE TEAM AFFIXED COOKIES TO A LABORATORY RHEOMETER AND DESIGNED A 3D-PRINTED OREOMETER TO STUDY THE INFLUENCES OF ROTATION RATE, FLAVOR, AMOUNT OF CREME, AND ENVIRONMENT ON OREOS.view more
CREDIT: CRYSTAL OWENS
WASHINGTON, April 19, 2022 – Imagine the perfect way to eat an Oreo. Perhaps you twist the top layer, separating the cookie into two parts, and then eat them one by one. Alternatively, you could dunk the treat into milk to soften it just the right amount. Or maybe, if you're a rheologist who studies complex fluids, you snack on the cookie while you test its mechanical properties in your lab.
In Physics of Fluids, by AIP Publishing, researchers from Massachusetts Institute of Technology characterized the flow and fracture of Oreos, finding the creme, which is officially "mushy" in rheological texture, tends to stick to one side of the cookie.
"Rheology can be used to measure the texture of food depending on the failure stresses and strains," said author Crystal Owens. "We were able to characterize Oreo creme as quantitatively mushy."
They placed Oreos in a rheometer, a laboratory instrument they used to measure torque as it fixed one side of the cookie in place and carefully twisted the other. After the filling failed and the cookie broke apart, they quantified the amount of creme on each wafer by visual inspection.
"I had in my mind that if you twist the Oreos perfectly, you should split the creme perfectly in the middle," said Owens. "But what actually happens is the creme almost always comes off of one side."
The authors investigated the influence of milk, cookie flavor, amount of filling, and rotation rate on the final creme distribution. After being dipped in milk, the cookies degraded quickly, crumbling after about 60 seconds. Flavor and filling seemed to have little effect on cookie mechanics, but breaking the cookies apart cleanly did depend on the rotation rate.
"If you try to twist the Oreos faster, it will actually take more strain and more stress to break them," said Owens. "So, maybe this is a lesson for people who are stressed and desperate to open their cookies. It'll be easier if you do it a little bit slower."
The creme may stick consistently to one side because of the way the cookies are manufactured and then oriented during packaging. Cookies from the same box often followed the same trends and varied from box to box, possibly due to different storage conditions.
By also designing an open-source, 3D-printed "Oreometer" powered by rubber bands and coins, the team hopes to encourage educators and Oreo enthusiasts to continue studying the cookies and learning about rheology.
"One of the main things we can do with the Oreometer is develop an at-home education and self-discovery plan, where you teach people about basic fluid properties like shear strain and stress," said author Max Fan.
The article, "On Oreology, the fracture and flow of 'milk's favorite cookie®'" is authored by Crystal E. Owens, Max R. Fan (范瑞), A. John Hart, and Gareth H. McKinley. The article will appear in Physics of Fluids on April 19, 2022 (DOI: 10.1063/5.0085362). After that date, it can be accessed at https://aip.scitation.org/doi/full/10.1063/5.0085362.
ABOUT THE JOURNAL
Physics of Fluids is devoted to the publication of original theoretical, computational, and experimental contributions to the dynamics of gases, liquids, and complex fluids. See https://aip.scitation.org/journal/phf.
There are many ways to eat an Oreo, from just taking a bite to my preferred method, dunking it in milk until it's deliciously soggy. But for many, the time-tested tradition is to twist the cookie in half and see which side got all the icing. And now, engineers with a little too much time on their hands have cracked the code of how to predict which side gets the icing.
Quartz reports that back in 2014, three Princeton graduate students studying mechanical and aerospace engineering were chatting about the "Oreo twist-off game," which would help them settle disputes as kids, wishbone-style. But one of them remembered having one friend as a kid who always won the game. How did he do it? They decided to experiment until they figured it out.
They put cookies into complicated machinery to test exactly what happens with different separation techniques, from twisting to pulling apart. They also tested on their family and friends, using bulk boxes of hundreds of Oreos. But it turns out that there's no complicated physics to the twist-off game, just manufacturing techniques.
If you want to predict which side will get the icing, just test one cookie from the box. Every other cookie in your entire package will turn out the same way. According to the Princeton scientists, just position your Oreo box so the text faces the right way, then take the cookie out from the upper left hand corner. If the icing is on the left side, it'll be on the left side for every other cookie, and the same goes if the icing is on the right.
Oreo won't give away its secrets, but the Princeton team thinks that during manufacturing, a machine pumps the icing onto one wafer and then puts the second wafer on top. The icing just sticks better to the first wafer, kind of like hot glue, and then the cookies are loaded into the packages all in the same way. It's unclear whether the same method goes for the Double Stuf and other varieties, so you'll just have to undergo your own delicious experiments to find out.
