New record-breaking thermoelectric material

Eco-friendly power generation from waste heat

Peer-Reviewed Publication

SEOUL NATIONAL UNIVERSITY

 

IMAGE: ▲ COLLEGE OF ENGINEERING AT SEOUL NATIONAL UNIVERSITY ANNOUNCED THAT PROFESSOR IN CHUNG'S GROUP IN THE SCHOOL OF CHEMICAL AND BIOLOGICAL ENGINEERING DEVELOPED A NEW THERMOELECTRIC MATERIAL OUTPERFORMING ANY OTHER BULK MATERIAL SYSTEMS. PROVIDED BY COLLEGE OF ENGINEERING AT SEOUL NATIONAL UNIVERSITY. view more 

CREDIT: SEOUL NATIONAL UNIVERSITY

◦ Prof. In Chung’s group at Seoul National University announced the development of the new record-breaking thermoelectric material consisting of less-toxic and inexpensive elements on Aug. 3 (Tue).

◦ Greater than 65% of the produced energy worldwide is lost as waste heat. Electric energy is mostly generated from fossil fuels. Accordingly, recovering such a huge amount of ubiquitous energy loss into usable forms of energy can contribute to solving energy and environmental crisis that humanity faces.

 

◦ Thermoelectric technology can contribute to solving such problems simultaneously. It converts heat to electric energy directly without releasing any environmentally undesirable chemical residues like greenhouse gases. However, current high-performance thermoelectric materials typically contain toxic lead and/or rare tellurium element, and their power generation efficiencies are low, making it difficult commercialize this technology.

◦ Prof. Chung’s group solved all these problems by developing a new ultrahigh performance polycrystalline thermoelectric material consisting of tin and selenium elements. Tin selenide-based material has attracted explosive academic attentions in 2014 because of the strikingly high thermoelectric figure of merit (ZT) of 2.6 reported in its single crystal form. However, the reproducibility of such high performance has been controversial so far. Futhermore, the corresponding polycrystalline materials have performed much poorer. Indeed, single crystal forms are unsuitable to mass production and commercial applications due to the high cost, lengthy and labor-intensitve production and mechanical brittleness.

◦ Prof. Chung’s group revealed the origin of poor performance of polycrystalline tin selenide materials, and developed a new synthesis process to solve all problems. As a result, the obtained new polycrystalline material exhibits thermoelectric figure of merit greater than 3.1 in a bulk form for the first time in history. Its record-breaking thermoelectric power generation efficiency exceeds 20%.

◦ Prof. Chung emphasized that “our new material open an era of the commercialization of ultrahigh performance practical thermoelectrics” like perovskite materials changing the paradigm of solar cell researches. Prof. Chung had also developed all-solid-state solar cells based on perovskite materials for the first time in 2012.

◦ This research result was published in the latest online edition (Aug. 3) of ‘Nature Materials’. This work was supported by Nano Material Technology Development and Mid-Career Research Programs throught the National Research Foundation of Korea grant funded by the Korean Government.

 

CAPTION

▲ Schematic illustration of thermoelectric power generation using wasted heat, and record-breaking thermoelectric performances of a new material developed by Professor Chung’s group. Provided by College of Engineering at Seoul National Universit y.

CREDIT

Seoul National University

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JOURNAL

Nature Materials

ARTICLE TITLE

Breaking thermoelectric performance limits

ARTICLE PUBLICATION DATE

1-Aug-2021

Extraordinary New Material Converts Waste Heat Into Energy

By NORTHWESTERN UNIVERSITY AUGUST 3, 2021

Purified tin selenide has extraordinarily high thermoelectric performance.

Perseverance, NASA’s 2020 Mars rover, is powered by something very desirable here on Earth: a thermoelectric device, which converts heat to useful electricity.

On Mars, the heat source is the radioactive decay of plutonium, and the device’s conversion efficiency is 4-5%. That’s good enough to power Perseverance and its operations but not quite good enough for applications on Earth.

A team of scientists from Northwestern University and Seoul National University in Korea now has demonstrated a high-performing thermoelectric material in a practical form that can be used in device development. The material — purified tin selenide in polycrystalline form — outperforms the single-crystal form in converting heat to electricity, making it the most efficient thermoelectric system on record. The researchers were able to achieve the high conversion rate after identifying and removing an oxidation problem that had degraded performance in earlier studies.

The polycrystalline tin selenide could be developed for use in solid-state thermoelectric devices in a variety of industries, with potentially enormous energy savings. A key application target is capturing industrial waste heat — such as from power plants, the automobile industry and glass- and brick-making factories — and converting it to electricity. More than 65% of the energy produced globally from fossil fuels is lost as waste heat. 

Purified tin selenide shown in pellet form. The material has extraordinarily high thermoelectric performance. Credit: Northwestern University

“Thermoelectric devices are in use, but only in niche applications, such as in the Mars rover,” said Northwestern’s Mercouri Kanatzidis, a chemist who specializes in the design of new materials. “These devices have not caught on like solar cells, and there are significant challenges to making good ones. We are focusing on developing a material that would be low cost and high performance and propel thermoelectric devices into more widespread application.”

Kanatzidis, the Charles E. and Emma H. Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences, is a co-corresponding author of the study. He has a joint appointment with Argonne National Laboratory.

Details of the thermoelectric material and its record-high performance were published on August 2, 2021, in the journal Nature Materials. 

In Chung of Seoul National University is the paper’s other co-corresponding author. Vinayak Dravid, the Abraham Harris Professor of Materials Science and Engineering at Northwestern’s McCormick School of Engineering, is one of the study’s senior authors. Dravid is a long-time collaborator of Kanatzidis’.

Thermoelectric devices are already well defined, says Kanatzidis, but what makes them work well or not is the thermoelectric material inside. One side of the device is hot and the other side cold. The thermoelectric material lies in the middle. Heat flows through the material, and some of the heat is converted to electricity, which leaves the device via wires.

The material needs to have extremely low thermal conductivity while still retaining good electrical conductivity to be efficient at waste heat conversion. And because the heat source could be as high as 400-500 degrees Celsius, the material needs to be stable at very high temperatures. These challenges and others make thermoelectric devices more difficult to produce than solar cells.

‘Something diabolical was happening’ 

In 2014, Kanatzidis and his team reported the discovery of a surprising material that was the best in the world at converting waste heat to useful electricity: the crystal form of the chemical compound tin selenide. While an important discovery, the single-crystal form is impractical for mass production because of its fragility and tendency to flake.

Tin selenide in polycrystalline form, which is stronger and can be cut and shaped for applications, was needed, so the researchers turned to studying the material in that form. In an unpleasant surprise, they found the material’s thermal conductivity was high, not the desirable low level found in the single-crystal form.

“We realized something diabolical was happening,” Kanatzidis said. “The expectation was that tin selenide in polycrystalline form would not have high thermal conductivity, but it did. We had a problem.” 

Upon closer examination, the researchers discovered a skin of oxidized tin on the material. Heat flowed through the conductive skin, increasing the thermal conductivity, which is undesirable in a thermoelectric device. 

A solution is found, opening doors

After learning that the oxidation came from both the process itself and the starting materials, the Korean team found a way to remove the oxygen. The researchers then could produce tin selenide pellets with no oxygen, which they then tested.

The true thermal conductivity of the polycrystalline form was measured and found to be lower, as originally expected. Its performance as a thermoelectric device, converting heat to electricity, exceeded that of the single crystal form, making it the most efficient on record.  

The efficiency of waste heat conversion in thermoelectrics is reflected by its “figure of merit,” a number called ZT. The higher the number, the better the conversion rate. The ZT of single-crystal tin selenide earlier was found to be approximately 2.2 to 2.6 at 913 Kelvin. In this new study, the researchers found the purified tin selenide in polycrystalline form had a ZT of approximately 3.1 at 783 Kelvin. Its thermal conductivity was ultralow, lower than the single-crystals.

“This opens the door for new devices to be built from polycrystalline tin selenide pellets and their applications explored,” Kanatzidis said.

Northwestern owns the intellectual property for the tin selenide material. Potential areas of application for the thermoelectric material include the automobile industry (a significant amount of gasoline’s potential energy goes out of a vehicle’s tailpipe), heavy manufacturing industries (such as glass and brick making, refineries, coal- and gas-fired power plants) and places where large combustion engines operate continuously (such as in large ships and tankers).

Reference: “Polycrystalline SnSe with a thermoelectric figure of merit greater than the single crystal” by Chongjian Zhou, Yong Kyu Lee, Yuan Yu, Sejin Byun, Zhong-Zhen Luo, Hyungseok Lee, Bangzhi Ge, Yea-Lee Lee, Xinqi Chen, Ji Yeong Lee, Oana Cojocaru-Mirédin, Hyunju Chang, Jino Im, Sung-Pyo Cho, Matthias Wuttig, Vinayak P. Dravid, Mercouri G. Kanatzidis and In Chung, 2 August 2021, Nature Materials.
DOI: 10.1038/s41563-021-01064-6

The research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (NRF-2020R1A2C2011111), Nano·Material Technology Development Program through the NRF grant funded by the Korean Government (NRF-2017M3A7B4049274 and NRF-2017M3A7B4049273) and the Institute for Basic Science (IBS-R009-G2).

 

USA

Barriers to voting in elections linked to increased odds of being uninsured

Peer-Reviewed Publication

COLUMBIA UNIVERSITY'S MAILMAN SCHOOL OF PUBLIC HEALTH

August 3, 2021-- Groups commonly targeted by voting restriction laws—those with low incomes, who are racial minorities, and who are young—are also less likely to be insured in states with more voting restrictions, according to a study by researchers at Columbia University Mailman School of Public Health and University of Alberta School of Public Health, Edmonton, Canada. However, those who are wealthier, white or older are no more likely to be uninsured irrespective of the level of voting restrictions.

This is one of the first studies to show the relationship between barriers to voting in elections and access to health insurance in the United States. The findings are published in The Lancet Regional Health --  Americas.

Implications of these findings underscore how access, or the lack of access, to power is associated with disparities in access to health care. The findings also provide evidence of the need for laws that assist rather than hinder minority and underserved groups in voting. 

“An often overlooked social determinant of health is access to power. When access to power is disproportionately distributed, health inequities develop. The right to vote is one of the most basic forms of access to power. By voting, citizens elect representatives who advocate for their interests,” noted Roman Pabayo, PhD, University of Alberta School of Public Health, and first author.

The researchers used data collected from 242, 727 adults in the 50 states and District of Columbia participating in the U.S. 2017 Behavioral Risk Factor Surveillance System (BRFSS). To quantify voting accessibility, the Cost of Voting Index (COVI), a global measure of barriers to voting within a state during a US election was used. The researchers adjusted for racial/ethnic identity, household income, and age group.

Many U.S. states have introduced barriers or restrictions on voting. Examples of voting restrictions include photo ID laws, no early voting, and same day registration are not allowed for elections. These laws are similar to "Jim Crow" laws which incorporated voting restrictions such as voter suppression and may reduce representation in legislative bodies. These same disadvantaged groups are thus less likely to have representatives to advocate for their interests and lifesaving goods, such as health insurance.

The association of greater voter restrictions and an overall increased odds of being uninsured was observed among Non-Hispanic Black, Hispanic, Asian, and other Non-Hispanic U.S. adults, but not among White Non-Hispanic and Native U.S. adults. Likewise, an increase in voting restrictions was observed among adults from low-income households, but not among those with incomes greater than $75,000. This association was observed among young adults but not among those aged 45 to 64.

Thus, in order to decrease health inequities, such as the disparities in health care access, voting restrictions that disproportionately affect racial and demographic groups, should be removed, according to the researchers.

“At the core of any democracy is the notion that we elect leaders to serve our best interests. When some groups are excluded from the democratic process, their voices are not heard, and the consequences can be deadly,” said Peter Muennig, MD, professor of health policy and management at Columbia Mailman School, and senior author. “The next step in this process is to explore other, broader consequences of voter restriction laws. Are they associated with shootings? Incarcerations for possession of substances that are legal in other states? Overall mortality?"

“When restrictions are more likely to prevent racial minorities, younger adults, and those from low socioeconomic backgrounds, from voting, legislation and policies that benefit their health are less likely to be enacted. Thus, ensuring the right to vote for all citizens may be one way to reduce population health inequities,” said Pabayo.

Co-authors are Sze Yan Liu, Montclair State University; Erin Grinshteyn, University of San Francisco; and Daniel Cook, University of Nevada.

Columbia University Mailman School of Public Health

Founded in 1922, the Columbia University Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Columbia Mailman School is the seventh largest recipient of NIH grants among schools of public health. Its nearly 300 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change and health, and public health preparedness. It is a leader in public health education with more than 1,300 graduate students from 55 nations pursuing a variety of master’s and doctoral degree programs. The Columbia Mailman School is also home to numerous world-renowned research centers, including ICAP and the Center for Infection and Immunity. For more information, please visit www.mailman.columbia.edu.

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JOURNAL

The Lancet Regional Health - Americas

DOI

10.1016/j.lana.2021.100026

ARTICLE TITLE

Barriers to Voting and Access to Health Insurance Among US Adults: A Cross-Sectional Study

 

EU project will develop, upscale and disseminate soil healing strategies

TUdi: Transforming unsustainable management of soils in key agricultural systems in EU and China. Developing an integrated platform of alternatives to reverse soil degradation

Grant and Award Announcement

PENSOFT PUBLISHERS

 

IMAGE: TRANSFORMING UNSUSTAINABLE SOIL MANAGEMENT IN THE EU AND CHINA. DEVELOPING AN INTEGRATED PLATFORM FOR REVERSING SOIL DEGRADATION. view more 

CREDIT: TUDI PROJECT

TUdi is conceived as a transformative cooperative project which aims to develop, upscale and popularise soil healing strategies in three major agricultural systems and farm typologies across Europe, China and New Zealand. To do this, TUdi relies on 15 research institutions and SMEs from all over the world, as well as a network of 42 cooperating stakeholder organisations and 66 long-term experiments and monitored farms in the participating countries.

Aimed to lead the way in improving soil health across EU, China and New Zealand, TUdi will develop healthy and productive agricultural ecosystems, which are among the most challenging UN development goals for 2030, including zero hunger, no poverty, climate action and life on land.

“Achieving global and regional food security and soil based ecosystem services depends on our ability to use the best science and experience,” comments project Coordinator José A. Gómez of the Spanish National Research Council (CSIC), Spain. ”In this way, we will drive widespread adoption of technologies to reverse degradation of agricultural soils and increase soil quality for food production, without damaging the wider environment.” The project is co-coordinated by Xiaoping Zhang of Northwest A&F University (NWAFU), China. 

Although monitoring the degradation of soil quality has progressed, less has been achieved to reverse soil degradation. About two billion people and 1.9 billion hectares of land are affected by land degradation globally, with an estimated cost to the global economy between $18-20 trillion USD annually. The European Commission estimates that current management practices result in approximately 60-70% of EU soils being unhealthy, with a further uncertain percentage of unhealthy soils due to poorly quantified pollution issues.

Multiple comprehensive EU and Chinese initiatives recognise the challenge of increasing agricultural production to supply the growing demands for healthy and sustainable food, while at the same time conserving their soil resource base. 

Against this background, the TUdi project plans four coherent steps: 

1. Engaging and cooperating with multiple stakeholders to identify and understand their needs and possibilities for strategies to cope with soil degradation
2. Developing a set of farming planning tools to facilitate implementation of fertilization and strategies for soil degradation control and soil restoration at farm scale
3. Providing different types of stakeholders with a thorough understanding of the impact of these soil restoring strategies
4. Scaling up the adoption of sustainable use of soils in a large number of multiple farms 

To mark the start of the TUdi project, its kick-off meeting was held on 22 and 23 July 2021 in an online environment. Despite the time difference, 35 people from 15 organisations across 2 continents and 2 islands attended. China, Hungary, Spain, Bulgaria, Czechia, Austria, New Zealand, the UK and Italy join forces in this four-year transcontinental research endeavour.  

 

Microwave-powered rocket propulsion gets a boost

Researchers led by the University of Tsukuba explore the possibility of launching rockets using a high-power beam of microwave radiation

Peer-Reviewed Publication

UNIVERSITY OF TSUKUBA

Tsukuba, Japan – Sending a rocket into space typically requires about 90% of the rocket’s initial weight to be fuel. This limitation could be overcome by wirelessly transmitting the needed power to the rocket through a beam of microwave radiation. A research team from Japan has investigated the viability of using such microwave-powered propulsion for real-world applications.

In a study published this month in the Journal of Spacecraft and Rockets, researchers led by the University of Tsukuba have demonstrated wireless power transmission via microwaves for a free-flying drone and determined the efficiency of this process.

Previous analyses of this kind were carried out decades ago and mostly considered microwaves of a low frequency (a few gigahertz; GHz). Given that the power transmission efficiency increases as the operating frequency is raised, the team behind this latest research used microwaves with a relatively high frequency (28 GHz). The team’s drone weighed roughly 0.4 kilograms and hovered for 30 seconds at a height of 0.8 meters above the source of the microwave beam.

“We used a sophisticated beam-tracking system to ensure that the drone received as much of the microwave power as possible,” says Kohei Shimamura, lead author of the study. “Moreover, to further increase the transmission efficiency, we carefully tuned the phase of the microwaves using an analog phase shifter that was synchronized with GPS units.”

The researchers measured the efficiencies of the power transfer through the beam (4%), the capture of microwaves by the drone (30%), the conversion of microwaves to electricity for propulsion (40%), and other relevant processes. Based on this information and an analytical formula, they calculated the overall power transmission efficiency in their experiment to be 0.43%. For comparison, in a previous study, the team measured the total transmission efficiency for a fixed-position (rather than free-flying) drone to be 60.1%.

“These results show that more work is needed to improve the transmission efficiency and thoroughly evaluate the feasibility of this propulsion approach for aircraft, spacecraft, and rockets,” explains Shimamura. “Future studies should also aim to refine the beam-tracking system and increase the transmission distance beyond that demonstrated in our experiment.”

Although microwave-powered rocket propulsion is still in its early stages, it could someday become a superior way to launch rockets into orbit given the high onboard-fuel demands of conventional propulsion techniques.

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The article, “28 GHz Microwave-Powered Propulsion Efficiency for Free-Flight Demonstration,” was published in the Journal of Spacecraft and Rockets at DOI: 10.2514/1.A35044

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DOI

10.2514/1.A35044

ARTICLE TITLE

28 GHz Microwave-Powered Propulsion Efficiency for Free-Flight Demonstration

ARTICLE PUBLICATION DATE

4-Jul-2021

 

Measuring nitrogen in green manures

by Emily Matzke, American Society of Agronomy

A crimson clover plant, which is generally recommended to grow in a mixture of grasses, which was used in this study. Credit: Sandra Wayman

Both chemical fertilizers and cover crops can help build the nitrogen content in soil. But cover crops come with many other benefits, like improving soil structure and boosting beneficial microbes.

Researchers at Cornell University are looking at ways to help breed better cover crops, also known as green manures, that could help farmers in their quest to grow crops in the most sustainable way. Their results were published in Crop Science, a publication of the Crop Science Society of America.

Katherine Muller and her team are working on strategies to measure nitrogen fixation in breeding programs for two common cover crops: crimson clover and hairy vetch. Both crops can pull nitrogen from the air to help them grow. This is called nitrogen fixation.

"Green manures are crops used to improve soil fertility," says Muller. "They help the soil by adding nutrients. We look at legumes, which bring nitrogen into the soil due to their symbiotic relationship with bacteria."

The use of legume green manures has been around for thousands of years. However, after the 1950s, chemical fertilizers became the main nitrogen source for farmers in developed countries. This is because two scientists, Haber and Bosch, found a way to pull nitrogen from the air, and make chemical fertilizer.

Though this type of fertilizer is productive, it also takes energy to make it—and it can easily slip into water bodies if not managed correctly.

A root system of a hairy vetch plant, with nodules that contain a symbiotic nitrogen fixing bacteria. Credit: Katherine Muller

"Cover crops are important ecological management tools," says Muller. "They foster microbial communities and put nutrients in the soil. Essentially, they help build fertile soil that can supply nutrients when plants need them."

The use of cover crops can be risky to farmers because they cannot determine the exact amount of nitrogen supplied to the soil. Chemical fertilizers allow for the exact calculation of the amount of nitrogen applied to a crop. But how much nitrogen is provided by each type of cover crop isn't a known number.

The amount of nitrogen supplied by a legume cover crop depends on how well it grows and how much of its nitrogen comes from fixation versus uptake from soil. Currently, cover crop seeds available do not have selective breeding for nitrogen fixation—a valuable trait.

Plant breeders are working to develop cover crop varieties that reduce the risks and increase benefits to farmers. They hope that better varieties will increase the use of cover crops as an alternative to chemical fertilizer. Nitrogen fixation is one of their top priorities for legume green manures.

"We aim to help plant breeders develop strategies to target nitrogen fixation in cover crops," explains Muller. "Because nitrogen fixation is a complicated trait that changes as plants grow, the timing of measurements is important."

For farmers, the most important measurement of nitrogen fixation is when the crop is terminated. Legume green manures are usually terminated in the late flowering stage. Earlier termination means the crop is likely to resprout and become a weed. However, breeding programs for hairy vetch and crimson clover cannot take that measurement, as they need to remove the plant before cross-pollination.

Hairy vetch ripe seeds, which were used in the study to display kinds of samples and measurements available to breeders. Credit: Sandra Wayman

"Our team did a field experiment with an active breeding program," says Muller. "We collected plant tissues and measured nitrogen fixation. We were able to tell how much of the plant's nitrogen comes from fixation versus the soil."

The team tested three kinds of samples that a plant breeder may take to compare them to the sample most relevant to farmers. They then measured nitrogen fixation by sending their samples to a lab that measures total nitrogen content and the abundance of a naturally occurring stable isotope.

Nitrogen from soil usually has a higher abundance of the nitrogen stable isotope than nitrogen from fixation. This allows researchers to estimate the proportion of nitrogen a plant obtains from soil versus fixation.

"Our recommendation is to collect stems from each plant in the early flowering stage to measure the nitrogen fixation via stable isotopes," says Muller. "This provides a good proxy for nitrogen fixation in whole plants, measured in the late flowering stage that is more relevant to farmers."

According to Muller, if breeders are going to add one measurement, it should be this. The proportion of nitrogen obtained by fixation often does not correlate with plant size or other measurements.

"It is important to measure actual nitrogen fixed in the cover crop because it can vary," says Muller. "Farmers want to know how much nitrogen they are bringing into their fields. We need to accurately measure and provide this information to help farmers make decisions. We hope our research will encourage more farmers to adopt legumes cover crops as a nitrogen source."

Balancing nitrogen for sunflowers

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More information: Katherine E. Muller et al, Estimating agronomically relevant symbiotic N fixation in green manure breeding programs, Crop Science (2021). DOI: 10.1002/csc2.20517

Provided by American Society of Agronomy 

 

Most comprehensive review yet of keto diets finds heart risks, cancer risk, dangers to pregnant women and kidney patients

Peer-Reviewed Publication

PHYSICIANS COMMITTEE FOR RESPONSIBLE MEDICINE

WASHINGTON—In the most comprehensive analysis yet of ketogenic (keto) diets, a review in Frontiers in Nutrition finds keto diets place pregnant women and kidney disease patients at risk of adverse health effects. The review, Ketogenic Diets and Chronic Disease: Weighing the Benefits Against the Risks, also found that for most people, the possible long-term risks of the keto diet, including heart disease, cancer, diabetes, and Alzheimer's disease, outweigh its possible benefits.

“The typical keto diet is a disease-promoting disaster,” says lead review author Lee Crosby, RD, nutrition education program manager at Physicians Committee for Responsible Medicine. “Loading up on red meat, processed meat, and saturated fat and restricting carbohydrate-rich vegetables, fruits, legumes, and whole grains is a recipe for bad health.”

Five key findings of the Frontiers in Nutrition review paper are:

1. Keto diets may be especially unsafe for women who are pregnant or may become pregnant—low-carb diets are linked to a higher risk of neural tube defects in the baby, even when women take folic acid.
2. Higher-protein keto diets could hasten kidney failure in those with kidney disease.
3. Keto diets raise “bad cholesterol” levels for many patients.
4. Keto diets are presented as a panacea, but they are not likely to be safe long term.
5. Restricting carbohydrate skews the diet toward cancer-causing foods. In fact, typical keto foods have been linked to an increased risk of heart disease, cancer, diabetes, and Alzheimer's—often the very diseases they are touted to help.

The term “ketogenic diet” generally refers to a diet that is very low in carbohydrate, modest in protein, and high in fat. This mix of fuels aims to induce ketosis, or the production of ketone bodies that serve as an alternate energy source for neurons and other cell types that cannot directly metabolize fatty acids.

Keto diets have been promoted for weight loss and, less commonly, for other health reasons—seizure disorders, obesity and weight management, type 1 and type 2 diabetes, fatty liver disease, cancer, Alzheimer’s disease, heart disease, kidney health, and prepregnancy and pregnancy—all of which were considered in this review. It also looked at potential long-term effects on health.

“In addition to the significant risks to kidney disease patients and pregnant women, keto diets are risky for others, too, as these diets can increase LDL cholesterol levels and may increase overall chronic disease risk,” Crosby explains. “While keto can reduce body weight short term, this approach is not more effective than other weight-loss diets.”

Researchers found that the only well-supported use for this dietary approach is to reduce seizure frequency in some individuals with drug-resistant epilepsy.

Crosby conducted the review with colleagues from New York University’s Grossman School of Medicine; New York City Health and Hospital at Bellevue; University of Pennsylvania; Loma Linda University; and George Washington University School of Medicine.

Founded in 1985, the Physicians Committee for Responsible Medicine is a nonprofit organization that promotes preventive medicine, conducts clinical research, and encourages higher standards for ethics and effectiveness in education and research.

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JOURNAL

Frontiers in Nutrition

DOI

https://doi.org/10.3389/fnut.2021.702802

ARTICLE TITLE

Ketogenic Diets and Chronic Disease: Weighing the Benefits Against the Risks

ARTICLE PUBLICATION DATE

16-Jul-2021

DR.TRUMP'S FAVORITE SNAKE OIL 

New study points to toxic potential of hydroxychloroquine in mammalian cells

Experts from Keck School of Medicine of USC conduct the first investigation of the DNA-damaging and mutagenic effects of the drug in mammalian cells

Peer-Reviewed Publication

KECK SCHOOL OF MEDICINE OF USC

During the height of the pandemic, as scientists worldwide raced to develop a vaccine, hydroxychloroquine (HCQ) emerged as a flashpoint of controversy. Pitting proponents of using the drug to fight COVID-19 against skeptics citing a lack of evidence of efficacy, the debate spilled into public view, polarizing national and international opinion.

Now, a new study published in the journal DNA Repair shows, for the first time, HCQ’s genotoxicity in mammalian cells. The study was led by Ahmad Besaratinia, PhD, professor of research in the Department of Population and Public Health Sciences at the Keck School of Medicine of USC.

“The uproar over HCQ drew our group’s attention, and we realized that, although the drug has been widely used for the treatment of diseases ranging from malaria to rheumatoid arthritis, its exact mechanisms of action are only beginning to be understood,” Besaratinia says. “Most importantly, there was no data on whether HCQ has adverse effects on the genome.”

Hydroxychloroquine shows mutagenic effects at clinical achievable dose

Besaratinia’s study demonstrated conclusively that HCQ exhibits DNA-damaging and mutagenic effects at a clinically achievable dose. He notes that the dosages were critical to the findings. “We conducted the study using a cell culture system derived from embryonic mouse cells. Whereas many in vitro experiments administer unrealistically high levels of a drug for testing, we used therapeutic doses of HCQ that are actually given to patients,” he says.

Use of HCQ has long been associated with cardiotoxicity and ophthalmologic and gastrointestinal complications. Besaratinia’s study suggests the possibility of additional side effects that might impact patient populations. For instance, mutations induced by DNA damage are the cause of many chronic diseases including cancer. “This drug is capable of inducing genetic mutation, which means we must carefully measure the risks and benefits of its use, especially in the context of clinical trials,” he says.

Besaratinia and his team performed the study during lockdown, when USC’s campus was largely closed. “Some scientists doing COVID-19-related research were exempt from the university’s stay-at-home order,” Besaratinia says. “We were part of a limited number of groups allowed to have one designated person at a time report to the lab. The hope was that our work could help shed light on the risks versus benefits of using HCQ in a variety of contexts.”

Weighing risks and benefits in decision-making

Though the study did not specifically evaluate HCQ’s ability to treat COVID-19, it did raise warnings about using the drug without fully assessing its potential for harm – and the need for informing volunteers in clinical trials about its potential adverse effects. “It is important to distinguish between the use of this drug in clinical trials versus using it to treat diseases for which it has been proven effective over the course of decades,” Besaratinia says. “If a patient’s need for HCQ outweighs the risks of using the drug, it makes perfect sense to prescribe it. But when it comes to healthy volunteers signing up for a clinical trial, they need to be aware of what the side effects may be so they can make an informed decision.”

Besaratinia points out that interspecies differences (between mice and humans), as well as in vitro versus in vivo conditions, may impact both the pharmacokinetics and pharmacodynamics of drugs like HCQ and that his team’s findings must now be validated. He says the need for follow up studies is pressing.

“Given the substantial percentage of people across the globe receiving HCQ for the treatment of various chronic diseases or in the context of clinical trials for COVID-19, our findings may have significant implications for safety monitoring in patient populations,” he says.

About the Study

The study’s additional authors are Stella Tommasi, PhD, assistant professor of research, and Andrew Caliri, research laboratory technician, both of the Department of Population and Public Health Sciences at the Keck School of Medicine of USC.

The study was supported by grants from the National Institute of Dental and Craniofacial Research of the National Institutes of Health (1R01DE026043) and the University of California Tobacco-Related Disease Research Program (28IR-0058 and T311R-1839).

About Keck School of Medicine

Founded in 1885, the Keck School of Medicine of USC is one of the nation’s leading medical institutions, known for innovative patient care, scientific discovery, education and community service. Medical and graduate students work closely with world-renowned faculty and receive hands-on training in one of the nation’s most diverse communities. They participate in cutting-edge research as they develop into tomorrow’s health leaders. With more than 900 resident physicians across 50 specialty and subspecialty programs, the Keck School is the largest educator 

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JOURNAL

DNA Repair

DOI

10.1016/j.dnarep.2021.103180

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animal tissue samples

ARTICLE TITLE

Hydroxychloroquine induces oxidative DNA damage and mutation in mammalian cells

 

Iowa school districts with strong teachers unions more likely to adopt mask mandates

New study suggests teachers across the country can play influential role in pandemic safety as students go back to school this fall

Peer-Reviewed Publication

GEORGE WASHINGTON UNIVERSITY

 

IMAGE: A NEW STUDY SUGGESTS TEACHERS ACROSS THE COUNTRY CAN PLAY INFLUENTIAL ROLE IN PANDEMIC SAFETY AS STUDENTS GO BACK TO SCHOOL THIS FALL view more 

CREDIT: GW

WASHINGTON (Aug. 2, 2021)—School districts in Iowa were more likely to adopt COVID-19 mask mandates if they had a strong teachers union, according to a study in the August issue of the journal Health Affairs. The new study suggests teachers unions may play a crucial role in ensuring that COVID-19 recommendations from the U.S. Centers for Disease Control and Prevention are implemented at the local level.

“Safely reopening schools during the COVID-19 pandemic is one of the most pressing public health challenges facing the nation this fall,” Adam Dean, lead author and an assistant professor of political science at the George Washington University, said. “Our study suggests teachers unions could play an important role in helping to prevent the spread of COVID-19.”

Dean and his colleagues knew that teachers unions supported mask mandates, but no one had studied the issue to see if union demands lead to the adoption of this important safety measure. To find out, the research team examined proprietary data on school district unionization and mask mandates from the Iowa State Education Association, the teachers union in the state.

The researchers found that the probability of schools adopting a mask mandate increased along with the teachers’ unionization rate. They also found that the political partisanship of union members made a big difference; school districts with Democratic leaning union members were more likely than districts with Republican union members to adopt mask requirements.

Last fall, the CDC strongly encouraged schools to require mask wearing as part of a strategy to prevent the spread of COVID-19. However, there was no national requirement for school districts to go along with the recommendation. In Iowa and many other states, policies regarding mask wearing were left up to local school districts.

Although the study was conducted in Iowa, Dean and his colleagues think the results may hold true for schools in other states as well. “Our study is the first to look at the role that labor unions play in helping to make schools safer during the pandemic, not just for teachers, but for students and parents as well.” Public health experts say that mask mandates in schools can help prevent the spread of the COVID-19 virus, including the Delta variant

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In addition to Dean, the research team included Jamie McCallum, an associate professor at Middlebury College; Simeon Kimmel, an assistant professor at Boston University; and Atheendar Venkataramani, an assistant professor at the University of Pennsylvania.

The paper, “Iowa School Districts Were More Likely to Adopt COVID-19 Mask Mandates Where Teachers Were Unionized,” was published Aug. 2 in the journal Health Affairs. 

(Link: https://www.healthaffairs.org/doi/abs/10.1377/hlthaff.2020.02518)

 

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JOURNAL

Health Affairs

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Iowa School Districts Were More Likely to Adopt COVID-19 Mask Mandates Where Teachers Were Unionized

ARTICLE PUBLICATION DATE

2-Aug-2021

AMERICA THE AUTOCRACY

From Health Affairs: Democracies provide stronger universal health coverage than autocracies

Peer-Reviewed Publication

HEALTH AFFAIRS

Despite widespread recognition that universal health coverage is a political choice, the roles that a country’s political system plays in ensuring essential health services and minimizing financial risk remain poorly understood. To assess the relationships that democratic quality has with universal health coverage and government health financing, Tara Templin of Stanford University and coauthors examine both private and government observational data and indices from 170 countries from 1990 to 2019. Of those countries, 73 were classified as democratic and the remainder autocratic. The authors found that for the democratic countries, per person government health spending increased from $326 to $601 during the study period; in contrast, in autocratic countries the per person spending grew less dramatically, going from $77 to $192. According to the authors, democracies are also more likely than autocracies to maintain universal health coverage, even amid economic recessions, which may have significance for the economic turndown spurred by the COVID-19 pandemic. During these times, the authors note, global institutions and development assistance providers may need to adjust their policy recommendations and activities to achieve the best possible results in countries where political leaders lack sufficient electoral incentives to provide high-quality health care to the citizenry.

Also in the issue:

• Trust In Governments And Health Workers Low Globally, Influencing Attitudes Toward Health Information, Vaccines; Corrina Moucheraud and coauthors from the University of California Los Angeles
• Competition From Biosimilars Drives Price Reductions For Biologics In The French Single-Payer Health System; James C. Robinson of the University of California Berkeley and Quentin Jarrion of the University Hospitals of Reims (France)
• Pandemic Fatigue: The Effects Of The COVID-19 Crisis On Public Trust And Compliance With Regulations In Israel; Moran Bodas and Kobi Peleg of the Gertner Institution (Israel)

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Health Affairs is the leading peer-reviewed journal at the intersection of health, health care, and policy. Published monthly by Project HOPE, the journal is available in print and online. Late-breaking content is also found through healthaffairs.org, Health Affairs Today, and Health Affairs Sunday Update.

Stay Up To Date With Health Affairs’ COVID-19 Resource Center: We’ve gathered blogs and journal articles, along with relevant content from our journal archive: lessons from previous pandemics, including school closures during the Spanish flu; public health preparedness; and communicating risk.

Project HOPE is a global health and humanitarian relief organization that places power in the hands of local health care workers to save lives across the globe. Project HOPE has published Health Affairs since 1981. 

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JOURNAL

Health Affairs

ARTICLE TITLE

Democracies Linked To Greater Universal Health Coverage Compared With Autocracies, Even In An Economic Recession

ARTICLE PUBLICATION DATE

2-Aug-2021

Disclaimer: AAAS and EurekAlert! ar

 

Vapor-collection technology saves water while clearing the air

System could reclaim pure water from power plant cooling towers; at-scale prototypes tested on MIT facilities have proven effective.

Business Announcement

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

About two-fifths of all the water that gets withdrawn from lakes, rivers, and wells in the U.S. is used not for agriculture, drinking, or sanitation, but to cool the power plants that provide electricity from fossil fuels or nuclear power. Over 65 percent of these plants use evaporative cooling, leading to huge white plumes that billow from their cooling towers, which can be a nuisance and, in some cases, even contribute to dangerous driving conditions.

Now, a small company based on technology recently developed at MIT by the Varanasi Research Group is hoping to reduce both the water needs at these plants and the resultant plumes — and to potentially help alleviate water shortages in areas where power plants put pressure on local water systems.

The technology is surprisingly simple in principle, but developing it to the point where it can now be tested at full scale on industrial plants was a more complex proposition. That required the real-world experience that the company’s founders gained from installing prototype systems, first on MIT’s natural-gas-powered cogeneration plant and then on MIT’s nuclear research reactor.

In these demanding tests, which involved exposure to not only the heat and vibrations of a working industrial plant but also the rigors of New England winters, the system proved its effectiveness at both eliminating the vapor plume and recapturing water. And, it purified the water in the process, so that it was 100 times cleaner than the incoming cooling water. The system is now being prepared for full-scale tests in a commercial power plant and in a chemical processing plant.

“Campus as a living laboratory”

The technology was originally envisioned by professor of mechanical engineering Kripa Varanasi to develop efficient water-recovery systems by capturing water droplets from both natural fog and plumes from power plant cooling towers. The project began as part of doctoral thesis research of Maher Damak PhD ’18, with funding from the MIT Tata Center for Technology and Design, to improve the efficiency of fog-harvesting systems like the ones used in some arid coastal regions as a source of potable water. Those systems, which generally consist of plastic or metal mesh hung vertically in the path of fogbanks, are extremely inefficient, capturing only about 1 to 3 percent of the water droplets that pass through them.

Varanasi and Damak found that vapor collection could be made much more efficient by first zapping the tiny droplets of water with a beam of electrically charged particles, or ions, to give each droplet a slight electric charge. Then, the stream of droplets passes through a wire mesh, like a window screen, that has an opposite electrical charge. This causes the droplets to be strongly attracted to the mesh, where they fall away due to gravity and can be collected in trays placed below the mesh.

Lab tests showed the concept worked, and the researchers, joined by Karim Khalil PhD ’18, won the MIT $100K Entrepreneurship Competition in 2018 for the basic concept. The nascent company, which they called Infinite Cooling, with Damak as CEO, Khalil as CTO, and Varanasi as chairperson, immediately went to work setting up a test installation on one of the cooling towers of MIT’s natural-gas-powered Central Utility Plant, with funding from the MIT Office of Sustainability. After experimenting with various configurations, they were able to show that the system could indeed eliminate the plume and produce water of high purity.

Professor Jacopo Buongiorno in the Department of Nuclear Science and Engineering immediately spotted a good opportunity for collaboration, offering the use of MIT’s Nuclear Reactor Laboratory research facility for further testing of the system with the help of NRL engineer Ed Block. With its 24/7 operation and its higher-temperature vapor emissions, the plant would provide a more stringent real-world test of the system, as well as proving its effectiveness in an actual operating reactor licensed by the Nuclear Regulatory Commission, an important step in “de-risking” the technology so that electric utilities could feel confident in adopting the system.

After the system was installed above one of the plant’s four cooling towers, testing showed that the water being collected was more than 100 times cleaner than the feedwater coming into the cooling system. It also proved that the installation — which, unlike the earlier version, had its mesh screens mounted vertically, parallel to the vapor stream — had no effect at all on the operation of the plant. Video of the tests dramatically illustrates how as soon as the power is switched on to the collecting mesh, the white plume of vapor immediately disappears completely.

The high temperature and volume of the vapor plume from the reactor’s cooling towers represented “kind of a worst-case scenario in terms of plumes,” Damak says, “so if we can capture that, we can basically capture anything.”

Working with MIT’s Nuclear Reactor Laboratory, Varanasi says, “has been quite an important step because it helped us to test it at scale. … It really both validated the water quality and the performance of the system.” The process, he says, “shows the importance of using the campus as a living laboratory. It allows us to do these kinds of experiments at scale, and also showed the ability to sustainably reduce the water footprint of the campus.”

Far-reaching benefits

Power plant plumes are often considered an eyesore and can lead to local opposition to new power plants because of the potential for obscured views, and even potential traffic hazards when the obscuring plumes blow across roadways. “The ability to eliminate the plumes could be an important benefit, allowing plants to be sited in locations that might otherwise be restricted,” Buongiorno says. At the same time, the system could eliminate a significant amount of water used by the plants and then lost to the sky, potentially alleviating pressure on local water systems, which could be especially helpful in arid regions.

The system is essentially a distillation process, and the pure water it produces could go into power plant boilers — which are separate from the cooling system — that require high-purity water. That might reduce the need for both fresh water and purification systems for the boilers.

What’s more, in many arid coastal areas power plants are cooled directly with seawater. This system would essentially add a water desalination capability to the plant, at a fraction of the cost of building a new standalone desalination plant, and at an even smaller fraction of its operating costs since the heat would essentially be provided for free.

Contamination of water is typically measured by testing its electrical conductivity, which increases with the amount of salts and other contaminants it contains. Water used in power plant cooling systems typically measures 3,000 microsiemens per centimeter, Khalil explains, while the water supply in the City of Cambridge is typically around 500 or 600 microsiemens per centimeter. The water captured by this system, he says, typically measures below 50 microsiemens per centimeter.

Thanks to the validation provided by the testing on MIT’s plants, the company has now been able to secure arrangements for its first two installations on operating commercial plants, which should begin later this year. One is a 900-megawatt power plant where the system’s clean water production will be a major advantage, and the other is at a chemical manufacturing plant in the Midwest.

In many locations power plants have to pay for the water they use for cooling, Varanasi says, and the new system is expected to reduce the need for water by up to 20 percent. For a typical power plant, that alone could account for about a million dollars saved in water costs per year, he says.

“Innovation has been a hallmark of the U.S. commercial industry for more than six decades,” says Maria G. Korsnick, president and CEO of the Nuclear Energy Institute, who was not involved in the research. “As the changing climate impacts every aspect of life, including global water supplies, companies across the supply chain are innovating for solutions. The testing of this innovative technology at MIT provides a valuable basis for its consideration in commercial applications.”

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Written by David L. Chandler, MIT News Office

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METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Not applicable