Monday, October 31, 2022

New catalyst can turn smelly hydrogen sulfide into a cash cow

An illustration of the light-powered, one-step remediation process for hydrogen sulfide gas made possible by a gold photocatalyst created at Rice University.
Image Credit: Halas Group/Rice University

Hydrogen sulfide gas has the unmistakable aroma of rotten eggs. It often emanates from sewers, stockyards and landfills, but it is particularly problematic for refineries, petrochemical plants and other industries, which make thousands of tons of the noxious gas each year as a byproduct of processes that remove sulfur from petroleum, natural gas, coal and other products.

In a published study in the American Chemical Society’s high-impact journal ACS Energy Letters, Rice engineer, physicist and chemist Naomi Halas and collaborators describe a method that uses gold nanoparticles to convert hydrogen sulfide into high-demand hydrogen gas and sulfur in a single step. Better yet, the one-step process gets all its energy from light. Study co-authors include Rice’s Peter Nordlander, Princeton University’s Emily Carter and Syzygy Plasmonics’ Hossein Robatjazi.

“Hydrogen sulfide emissions can result in hefty fines for industry, but remediation is also very expensive,” said Halas, a nanophotonics pioneer whose lab has spent years developing commercially viable light-activated nanocatalysts. “The phrase ‘game-changer’ is overused, but in this case, it applies. Implementing plasmonic photocatalysis should be far less expensive than traditional remediation, and it has the added potential of transforming a costly burden into an increasingly valuable commodity.”

Bulking Up to Beat Bacteria

The inhibitor-binding site of the wild-type MexB pump. (a) The crystal structure of the inhibitor ABI-PP bound to the MexB trimer. Three MexB monomers are shown in green, blue, and red, representing the access, binding, and extrusion monomer, respectively. ABI-PP is shown as a yellow space-filling model. (b) A close-up view of the inhibitor binding site. The substrate translocation pathway is shown as a solid gray surface. The proximal and distal binding pockets are indicated in green and blue circles, respectively. The inhibitor binding pit is shown as a red surface. The ABI-PP molecule is represented as a yellow stick model. (c) A detailed view of the inhibitor-binding site. Carbon atoms of ABI-PP are indicated in yellow while amino acid residues are indicated in green. The classification of these amino acids is shown on the right side of the panel.
Image Credit: 2022 Yamasaki et al., Spatial Characteristics of the Efflux Pump MexB Determine Inhibitor Binding, Antimicrobial Agents and Chemotherapy

The medical profession is in the midst of losing an arms race. Bacterial antibiotic resistance doesn’t just threaten our ability to treat infection but our ability to carry out any treatment where infection is a risk. This includes a raft of life-saving surgeries ranging from coronary bypass operations to organ transplantation. In fact, the number of new antimicrobials being developed is declining each year. Understanding how bacteria resist the influence of antibiotics is essential to winning this arms race: it is time to make up ground.

In a study published this month in Antimicrobial Agents and Chemotherapy, researchers at Osaka University have produced new insights into the structure of a particular bacterial protein known as an efflux pump. This protein is involved in antibiotic resistance and its structure influences the ability of drugs to target it.

New MicroBooNE analysis takes a closer look at the sterile neutrino

MicroBooNE features state-of-the-art particle detection techniques and technology. The experiment studies neutrino interactions and is probing models of a theorized fourth neutrino called the sterile neutrino.
Photo Credit: Reidar Hahn, Fermilab

A new result from the MicroBooNE experiment at the U.S. Department of Energy’s Fermi National Accelerator Laboratory probes the Standard Model — scientists’ best theory of how the universe works. The model assumes there are three kinds of neutrinos. Yet for more than two decades, a proposed fourth kind of neutrino has remained a promising explanation for anomalies seen in earlier physics experiments. Finding the theorized sterile neutrino would be a major discovery and radical shift in our understanding of the universe.

The new analysis published in arXiv compares the experiment’s data to a model with a fourth, sterile neutrino to test their compatibility. MicroBooNE scientists found no evidence of the long-sought sterile neutrino in the parameter range explored.

The possibility that sterile neutrinos caused the yet-unexplained anomalies reported by previous experiments still remains. These include measurements by the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory, the MiniBooNE experiment at Fermilab, and several radiochemical and nuclear reactor neutrino experiments.

“This is the first time we’ve checked whether our data fit a specific sterile-neutrino model,” said Matt Toups, a Fermilab scientist and co-spokesperson for MicroBooNE. “We’ve excluded large sections of the sterile neutrino parameter space allowed by LSND. But there are still corners where a sterile neutrino could potentially be hiding.”

Reprogramming of immune cells shown to fight off melanoma

Illustration showing how miniature artificial protocells loaded with anti-microRNA-223 cargo can reprogram cancer-associated macrophages in larval and adult zebrafish leading them to be more pro-inflammatory and thus able to drive melanoma shrinkage
Image Credit: Paco Lopez Cuevas

A new way of reprogramming our immune cells to shrink or kill off cancer cells has been shown to work in the otherwise hard to treat and devastating skin cancer, melanoma. The University of Bristol-led discovery, published in Advanced Science today [31 October], demonstrates a new way to clear early stage pre-cancerous and even late-stage tumor cells.

Using miniature artificial capsules called protocells designed to deploy reprogramming cargoes that are taken up by inflammatory cells (white blood cells), the scientists show they were able to transform these cells into a state that makes them more effective at slowing down the growth and killing of melanoma cells. They showed that this was possible for both animal and human immune cells.

The study is the first to test the capacity of a protocell to deliver cargoes for reprogramming immune cells and offers a promising novel target for the development of cancer immunotherapies.

Paul Martin, Professor of Cell Biology in the School of Biochemistry at the University of Bristol and one of the study's lead authors explained what happens when our immune system comes into contact with cancer cells: "Our immune cells have a surveillance capacity which enables them to detect pre-cancerous cells arising at any tissue site in the body. However, when immune cells encounter cancer cells, they are often subverted by the cancer cells and instead tend to nourish them and encourage cancer progression. We wanted to test whether it might be possible to reprogram our immune system to kill these cells rather than nurture them."

New Tech Solves Longstanding Challenges for Self-Healing Materials

3D printed thermoplastic on woven-carbon fiber reinforcement.
Credit: North Carolina State University

Engineering researchers have developed a new self-healing composite that allows structures to repair themselves in place, without having to be removed from service. This latest technology resolves two longstanding challenges for self-healing materials, and can significantly extend the lifespan of structural components such as wind-turbine blades and aircraft wings.

“Researchers have developed a variety of self-healing materials, but previous strategies for self-healing composites have faced two practical challenges,” says Jason Patrick, corresponding author of the research paper and an assistant professor of civil, construction and environmental engineering at North Carolina State University.

“First, the materials often need to be removed from service in order to heal. For instance, some require heating in an oven, which can’t be done for large components or while a given part is in use. Second, self-healing only works for a limited period. For example, the material might be able to heal a few times, after which its self-repairing properties would significantly diminish. We’ve come up with an approach that addresses both of those challenges in a meaningful way, while retaining the strength and other performance characteristics of structural fiber-composites.”

Largest Potentially Hazardous Asteroid Detected in Eight Years

Twilight observations with the U.S. Department of Energy-fabricated Dark Energy Camera at Cerro Tololo Inter-American Observatory in Chile, a program of NSF’s NOIRLab, have enabled astronomers to spot three near-Earth asteroids, or NEAs, hiding in the glare of the sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years.
Image Credit: DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA/J. da Silva/Spaceengine

Twilight observations with the US Department of Energy-fabricated Dark Energy Camera at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF's NOIRLab, have enabled astronomers to spot three near-Earth asteroids (NEA) hiding in the glare of the Sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years.

An international team using the Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab, has discovered three new near-Earth asteroids (NEAs) hiding in the inner Solar System, the region interior to the orbits of Earth and Venus. This is a notoriously challenging region for observations because asteroid hunters have to contend with the glare of the Sun.

By taking advantage of the brief yet favorable observing conditions during twilight, however, the astronomers found an elusive trio of NEAs. One is a 1.5-kilometer-wide asteroid called 2022 AP7, which has an orbit that may someday place it in Earth’s path. The other asteroids, called 2021 LJ4 and 2021 PH27, have orbits that safely remain completely interior to Earth’s orbit. Also, of special interest to astronomers and astrophysicists, 2021 PH27 is the closest known asteroid to the Sun. As such, it has the largest general-relativity effects [1] of any object in our Solar System and during its orbit its surface gets hot enough to melt lead.

Ghost of a giant star

This image shows a spectacular view of the orange and pink clouds that make up what remains after the explosive death of a massive star — the Vela supernova remnant. This detailed image consists of 554 million pixels, and is a combined mosaic image of observations taken with the 268-million-pixel OmegaCAM camera at the VLT Survey Telescope, hosted at ESO’s Paranal Observatory.   OmegaCAM can take images through several filters that each let the telescope see the light emitted in a distinct color. To capture this image, four filters have been used, represented here by a combination of magenta, blue, green and red. The result is an extremely detailed and stunning view of both the gaseous filaments in the remnant and the foreground bright blue stars that add sparkle to the image. 
Hi-Res Zoomable Image
Credit: ESO/VPHAS+ team. Acknowledgement: Cambridge Astronomical Survey Unit

A spooky spider web, magical dragons or wispy trails of ghosts? What do you see in this image of the Vela supernova remnant? This beautiful tapestry of colors shows the ghostly remains of a gigantic star, and was captured here in incredible detail with the VLT Survey Telescope, hosted at the European Southern Observatory’s (ESO’s) Paranal site in Chile.

The wispy structure of pink and orange clouds is all that remains of a massive star that ended its life in a powerful explosion around 11 000 years ago. When the most massive stars reach the end of their life, they often go out with a bang, in an outburst called a supernova. These explosions cause shock waves that move through the surrounding gas, compressing it and creating intricate thread-like structures. The energy released heats the gaseous tendrils, making them shine brightly, as seen in this image.

In this 554-million-pixel image, we get an extremely detailed view of the Vela supernova remnant, named after the southern constellation Vela (The Sails). You could fit nine full Moons in this entire image, and the whole cloud is even larger. At only 800 light-years away from Earth, this dramatic supernova remnant is one of the closest known to us.

A better way to tell which species are vulnerable

Intertidal ecosystems containing species of mussels, barnacles, and algae were one of the systems with fluctuating populations analyzed by the team. They developed a new way to detect species that are vulnerable to perturbations, such as waves and storms that affect intertidal ecosystems.
Credits: Courtesy of the researchers | Massachusetts Institute of Technology

Wildfires, floods, pollution, and overfishing are among the many disruptions that can change the balance of ecosystems, sometimes endangering the future of entire species. But evaluating these ecosystems to determine which species are most at risk, in order to focus preservation actions and policies where they are most needed, is a challenging task.

Most such efforts assume that ecosystems are essentially in a state of equilibrium, and that external perturbations cause a temporary shift before things eventually return to that equilibrium state. But that assumption fails to account for the reality that ecosystems are often in flux, with the relative abundances of their different components shifting on timetables of their own. Now, a team of researchers at MIT and elsewhere have come up with a better, predictive way of evaluating these systems in order to rank the relative vulnerabilities of different species, and to detect species that are under threat but could otherwise go unnoticed.

Contrary to conventional ways of making such rankings today, they found, the species with the lowest population numbers or the steepest decline in numbers — criteria typically used today — are sometimes not the ones most at risk.

The findings are reported today in the journal Ecology Letters, in a paper by MIT associate professor of civil and environmental engineering Serguei Saavedra, recent doctoral student Lucas Medeiros PhD ’22, and three others.

Just like humans, more intelligent jays have greater self-control

A study has found that Eurasian jays can pass a version of the ‘marshmallow test’ – and those with the greatest self-control also score the highest on intelligence tests.
Photo Credit: Takashi Yanagisawa

This is the first evidence of a link between self-control and intelligence in birds.

Self-control - the ability to resist temptation in favor of a better but delayed reward – is a vital skill that underpins effective decision-making and future planning.

Jays are members of the corvid family, often nicknamed the ‘feathered apes’ because they rival non-human primates in their cognitive abilities. Corvids hide, or ‘cache’, their food to save it for later. In other words, they need to delay immediate gratification to plan for future meals. The researchers think this may have driven the evolution of self-control in these birds.

Self-control has been previously shown to be linked to intelligence in humans, chimpanzees and – in an earlier study by these researchers – in cuttlefish. The greater the intelligence, the greater the self-control.

The new results show that the link between intelligence and self-control exists across distantly related animal groups, suggesting it has evolved independently several times.

Of all the corvids, jays in particular are vulnerable to having their caches stolen by other birds. Self-control also enables them to wait for the right moment to hide their food without being seen or heard.

New Material for Perovskite Solar Cells Proposed in Russia

Scientists have proposed a new type of material for transporting electrons in perovskite solar cells.
 Photo Credit: Vladimir Petrov

Experts from the Ural Federal University and the Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences, together with other Russian scientists, have proposed a new type of material for one of the solar cell cells. The discovered compounds will significantly reduce the cost of solar cell production. An article with the results of the study was published in the New Journal of Chemistry.

Perovskite solar cells (PSCs) are a promising alternative to the familiar silicon cells, providing the same amount of energy with 180 times less material thickness. Their production technology is much simpler and cheaper than that of silicon cells. The problem with PSCs is their lack of stability. One of the most effective solutions today, as explained by the experts, is the selection of new materials that ensure the transport of the charge carriers after it is obtained in the perovskite layer itself.

The scientific team of the Ural Federal University and the Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences proposed a new type of material for transporting electrons in the PSCs, which has a number of advantages. According to the authors, with the new material they managed to achieve solar energy conversion efficiency of 12%, which is comparable with the average indicators of market analogues.

Thursday, October 27, 2022

Step by step

Berkeley researchers may be one step closer to making robot dogs our new best friends. Using advances in machine learning, two separate teams have developed cutting-edge approaches to shorten in-the-field training times for quadruped robots, getting them to walk — and even roll over — in record time.

In a first for the robotics field, a team led by Sergey Levine, associate professor of electrical engineering and computer sciences, demonstrated a robot learning to walk without prior training from models and simulations in just 20 minutes. The demonstration marks a significant advancement, as this robot relied solely on trial and error in the field to master the movements necessary to walk and adapt to different settings.

“Our work shows that training robots in the real world is more feasible than previously thought, and we hope, as a result, to empower other researchers to start tackling more real-world problems,” said Laura Smith, a Ph.D. student in Levine’s lab and one of the lead authors of the paper posted on arXiv.

In past studies, robots of comparable complexity required several hours to weeks of data input to learn to walk using reinforcement learning (RL). Often, they also were trained in controlled lab settings, where they learned to walk on relatively simple terrain and received precise feedback about their performance.

NUS researchers devise revolutionary technique to generate hydrogen more efficiently from water

An NUS team led by Assoc Prof Xue Jun Min (center) has found that light can trigger a new mechanism in a catalytic material used extensively in water electrolysis (held up by Mr. Zhong Haoyin), where water is broken down into hydrogen and oxygen. The result is a more energy-efficient method of obtaining hydrogen. Dr Vincent Lee Wee Siang (right) is a member of the research team.
 Credit: National University of Singapore

The team’s discovery that light can trigger a brand new electro-catalytic mechanism of water electrolysis could improve affordability of hydrogen as source of clean energy

A team of researchers from the National University of Singapore (NUS) have made a serendipitous scientific discovery that could potentially revolutionize the way water is broken down to release hydrogen gas - an element crucial to many industrial processes.

The team, led by Associate Professor Xue Jun Min, Dr Wang Xiaopeng and Dr Vincent Lee Wee Siang from the Department of Materials Science and Engineering under the NUS College of Design and Engineering (NUS CDE), found that light can trigger a new mechanism in a catalytic material used extensively in water electrolysis, where water is broken down into hydrogen and oxygen. The result is a more energy-efficient method of obtaining hydrogen.

This breakthrough was achieved in collaboration with Dr Xi Shibo from the Institute of Sustainability for Chemicals, Energy and Environment under the Agency for Science, Technology and Research (ASTAR); Dr Yu Zhigen from the Institute of High-Performance Computing under ASTAR; and Dr Wang Hao from the Department of Mechanical Engineering under the NUS CDE.

Overcoming resistance to colon cancer treatment

Colorectal cancer cells after treatment with FOLFORIXI chemotherapy for 34 weeks. Cell fibers (in green) and nuclei (in blue).
Credit: UNIGE-Nowak-Sliwinka

Colorectal cancer is one of the most common cancers. Its treatment is mainly based on chemotherapy. However, over time, chemotherapy induces resistance in the majority of patients, who end up being unresponsive to the drugs. As a result, the five-year survival rate for those affected is still low. After succeeding in reproducing this resistance in the laboratory, a team from the University of Geneva (UNIGE) has found a way to overcome it. The team has used an optimized combination of drugs belonging to the class of tyrosine kinase inhibitors, which take different pathways to attack cancer cells than chemotherapy. These results, to be found in the journal Cancers, open up new avenues for overcoming treatment resistance and for developing new therapies that are more targeted than chemotherapy.

Colorectal cancer is the third most diagnosed cancer in the world and second only to lung cancer in terms of mortality. It most often develops from the age of 50 in the terminal part of the colon. It results from a change in the DNA of certain cells present in this organ. These cells become cancerous and proliferate in an uncontrolled manner until they form a primary tumor. As in many cancers, these cells can migrate to other parts of the body and form secondary tumors. This is known as metastatic cancer.

While genetics play a role in the development of the disease, the presence of inflammatory bowel diseases (e.g. Crohn’s disease) and certain dietary habits (alcohol, red meat) are also risk factors. In the case of a primary tumor, treatment is based on surgery and chemotherapy. In the case of secondary tumors, it is based on a combination of chemotherapies. These treatments are non-targeted and aggressive. They cause significant side effects. They also lead to progressive resistance to treatment in the majority of patients.

Wednesday, October 26, 2022

Considering COVID a hoax is ‘gateway’ to belief in conspiracy theories

Data showed one strong trend suggesting that financial distress during the lockdown could have been a factor in adopting conspiracy theory beliefs about the pandemic – even among those who started off with low levels of conspiracist ideation.
Photo Credit: Lara Jameson

Belief that the COVID-19 pandemic was a hoax – that its severity was exaggerated or that the virus was deliberately released for sinister reasons – functions as a “gateway” to believing in conspiracy theories generally, new research has found.

In the two-survey study, people who reported greater belief in conspiracy theories about the pandemic – for which there is no evidence – were more likely to later report they believed that the 2020 presidential election had been stolen from Donald Trump through widespread voter fraud, which is also not true. Participants’ overall inclination to believe in conspiracy theories also increased more among those who reported believing COVID-19 was a hoax.

Based on the results, the Ohio State University researchers have proposed the “gateway conspiracy” hypothesis, which argues that conspiracy theory beliefs prompted by a single event lead to increases in conspiratorial thinking over time.

Preliminary evidence suggests a sense of distrust may function as one trigger.

“It’s speculative, but it appears that once people adopt one conspiracy belief, it promotes distrust in institutions more generally – it could be government, science, the media, whatever,” said senior author Russell Fazio, professor of psychology at Ohio State. “Once you start viewing events through that distrustful lens, it’s very easy to adopt additional conspiracy theories.”

International Collaboration Is Key to Addressing Global Climate Change

Estimated annual savings from deployed annual solar PV modules using global versus national market scenarios in China, Germany and the United States (2008-2020). 
Credit: Helveston, He and Davidson 2022

Study Quantifies for First Time Past and Future Country Cost Savings to Solar Industry from Globalized Supply Chains

The world will need to deploy renewable energy at an unprecedented speed and scale in the future to reduce carbon emissions that are driving climate change. The option of solar energy promises to play a crucial role in achieving a sustainable, low-carbon energy future, especially if the price of production continues to decline as it has over the last 40 years.

A new study published in Nature by a team of scientists including Gang He, assistant professor in the Department of Technology and Society in the College of Engineering and Applied Sciences at Stony Brook University, supports this concept. Findings from the paper reveal that the globalized supply chain of solar photovoltaics saved countries $67 billion in solar module production costs. The study also found that if strong nationalistic policies that limit the free flow of goods, talent and capital are implemented going forward, solar panel costs will be much higher by 2030.

Borrowing a shape from a to-go cup lid, a drone wing could learn how to sense danger faster

Researchers have discovered a new possible use for the dome shape that you would find on a to-go cup lid.
Credit: Pexels/Caleb Oquendo

The oddly satisfying small domes that you press on your soda’s to-go cup lid may one day save a winged drone from a nosedive.

Patterns of these invertible domes on a drone’s wings would give it a way to remember in microseconds what dangerous conditions feel like and react quickly. The study, conducted by researchers at Purdue University and the University of Tennessee, Knoxville, is among the first demonstrations of a metamaterial that uses its shape to learn how to adapt to its surroundings on its own. The paper is published in the journal Advanced Intelligent Systems.

Unlike humans and other living beings, autonomous vehicles lack ways to filter out information they don’t need, which slows their response time to changes in their environment.

“There’s this problem called ‘data drowning.’ Drones cannot use their full flight capability because there is just too much data to process from their sensors, which prevents them from flying safely in certain situations,” said Andres Arrieta, a Purdue associate professor of mechanical engineering with a courtesy appointment in aeronautical and astronautical engineering.

Dome-covered surfaces that can sense their surroundings would be a step toward enabling a drone’s wings to feel only the most necessary sensory information. Because it only takes a certain minimum amount of force to invert a dome, forces below this threshold are automatically filtered out. A specific combination of domes popped up and down at certain parts of the wing, for example, could indicate to the drone’s control system that the wing is experiencing a dangerous pressure pattern. Other dome patterns could signify dangerous temperatures or that an object is approaching, Arrieta said.

People with paranormal beliefs spooked by science and the COVID-19 vaccine

The largest supermoon appearance of 2022, identified as the Buck Moon, rises above the mountain line in Morgantown, July 13. New WVU sociological research shows people who believe in witchcraft, telekinesis and other forms of paranormal phenomenon are more likely to mistrust science and vaccines.
Photo Credit:David Malecki | West Virginia University

The number 13, telekinesis and witchcraft play a part in a person’s mistrust of science and vaccines, including the COVID-19 shot, according to research from West Virginia University sociologists.

Previous research has shown that people with conservative religious beliefs are more likely to lack confidence in the COVID-19 vaccine, but most studies have observed only mainstream or institutionalized religious forms. WVU researchers Katie Corcoran, Chris Scheitle and Bernard DiGregorio were curious whether paranormal beliefs — beliefs in astrology and spirits, for instance — would be associated with a similar lack of confidence.

“We were interested in looking at how religion, science and what we call ‘the enchanted worldview’ relate to each other,” said Corcoran, associate professor of sociology in the Eberly College of Arts and Sciences, explaining that the enchanted worldview incorporates traditional religious beliefs, like beliefs in angels, God, demons and spirits.

“It also incorporates the belief that crystals can heal, belief in astrology and belief that the world is enchanted, that there’s more than the empirical world, beyond just religion. So, this particular project looks at what we call paranormal beliefs, which cut across several different areas.”

Autistic women have increased risk of mental illness

Photo credit: Alexander Grey

Young men and women with autism are more affected by psychiatric conditions and are at increased risk of being threatened as a result of their mental illness, compared to people without autism. Practically vulnerable are autistic women. This is shown by researchers from the Karolinska Institutet in a study published in JAMA Psychiatry.

People with autism have an increased risk of suffering from mental illness. Current data indicates that women with autism are more vulnerable than autistic but are, but few studies have been able to establish that there are gender differences.

Researchers from Karolinska Institutet have now done a register-based cohort study with just over 1.3 million people in Sweden, which was followed from 16 to 24 years between 2001 and 2013. More than 20,000 of these were diagnosed with autism.

The researchers could see that by the age of 25, 77 out of 100 women with autism, compared to 62 out of 100 but with autism, had received at least one psychiatric diagnosis.

We saw an increased risk of eleven different psychiatric conditions, including depression, anxiety syndrome, self-harm behavior and insomnia, says Miriam Martini, PhD student in psychiatric epidemiology at Department of Medical Epidemiology and Biostatics at Karolinska Institutet and first author of the study.

A key regulator of cell growth deciphered

The SEA complex is composed of a cage-like core (SEACAT, blue) that regulates the activity of the wings (SEACIT, white and bright).
Credit: Ciencia Graficada

The mTOR protein plays a central role in cell growth, proliferation and survival. Its activity varies according to the availability of nutrients and some growth factors, including hormones. This protein is implicated in several diseases, including cancer, where its activity frequently increases. To better understand its regulation, a team from the University of Geneva (UNIGE), in collaboration with researchers from the Martin Luther University (MLU) of HalleWittenberg in Germany, and the recently inaugurated Dubochet Center for Imaging (UNIGE-UNIL-EPFL), has identified the structure of the SEA complex - an interdependent set of proteins - responsible for controlling mTOR. The discovery of this structure allows a better understanding of how cells perceive nutrient levels to regulate their growth. This work can be read in the journal Nature.

From yeast to humans, the mTOR protein (mammalian target of rapamycin) is the central controller of cell growth. This protein responds to various signals in the cell’s environment, such as nutrients and hormones, and regulates many fundamental cellular functions, such as protein and lipid synthesis, energy production by mitochondria and the organization of the cell’s structure. Disruptions in mTOR activity are the cause of several diseases, including diabetes, obesity, epilepsy and various types of cancer

Awareness of one’s own body is based on uncertainty and guesses

Researchers at Karolinska Institutet have found that the perception of one's own body is very based on the brain making guesses based on probability theory. It shows a study recently published in the journal eLife.

How we perceive our own body is largely based on probability assessments based on past experiences, in combination with sensory information such as vision and feeling, for example.

You could say that the experience of your own body is a statistical estimate of reality based on sensory information, sensorory uncertainty, and past experiences that can be summed up in the mathematical model explain Henrik Ehrsson, professor at the Department of Neuroscience, Karolinska Institutet.

Nestling birds recognize their local song ‘dialect’

The researchers discovered that the juvenile flycatchers clear response to their own song dialect helped them avoid learning songs from other species in the environment.
Photo credit: Tom Wallis

A recent study, published in Current Biology, led by researchers at Stockholm University and Uppsala University, has shown that juvenile songbirds react to hearing the songs they will eventually produce as adults, even when they are as young as 12 days old. Experiments conducted on nestling pied flycatchers across Europe demonstrate that they preferentially respond to songs from their own species and, remarkably, their own population.

Like human children learning language, juvenile songbirds learn their songs by listening to those produced by their parents and other adults. In both human language and songbird song, the learning process gives rise to small changes from one generation to the next, which leads to characteristic differences among populations, called dialects.

Metabolite product from pomegranate: Researchers identify way to boost tumor-fighting immune cells

A metabolite from pomegranates boosts tumor-fighting T cells, according to a study by Georg-Speyer-Haus, Goethe University Frankfurt and the LOEWE Centre Frankfurt Cancer Institute (FCI).
Photo credit: Markus Bernards

As part of an interdisciplinary project of the LOEWE Centre Frankfurt Cancer Institute (FCI), researchers from the Georg-Speyer-Haus in Frankfurt am Main, Germany, and Goethe University Frankfurt have succeeded in identifying a new approach for the therapy of colorectal cancer. In preclinical models and studies on human immune cells, they found that urolithin A, a metabolite product from pomegranate, sustainably improves the function of immune cells in their fight against cancer. After treatment with urolithin A, tumor-fighting immune cells become T memory stem cells which, due to their ability to divide, constantly supply the immune system with rejuvenated, non-exhausted T cells.

Colorectal cancer remains a disease with high mortality rates in advanced stages. In recent years, numerous research findings have improved early diagnosis and therapy, although unfortunately not all patients respond adequately to novel therapeutic approaches. Current research suggests that one characteristic of tumor diseases is immune dysfunction: immune cells that are supposed to fight the tumor are systematically suppressed by the tissue surrounding the tumor, the tumor microenvironment. As a result, T cells, which are our body's natural immune response against cancer, are restricted in their function, allowing the tumor to grow and spread uncontrollably.

Tree rings offer insight into devastating radiation storms

A University of Queensland study has shed new light on a mysterious, unpredictable and potentially devastating kind of astrophysical event.

A team led by Dr Benjamin Pope from UQ’s School of Mathematics and Physics applied cutting edge statistics to data from millennia-old trees, to find out more about radiation ‘storms.

“These huge bursts of cosmic radiation, known as Miyake Events, have occurred approximately once every thousand years but what causes them is unclear,” Dr Pope said. “The leading theory is that they are huge solar flares.

“We need to know more, because if one of these happened today, it would destroy technology including satellites, internet cables, long-distance power lines and transformers.

“The effect on global infrastructure would be unimaginable.”

Enter the humble tree ring.

First author UQ undergraduate math student Qingyuan Zhang developed software to analyze every available piece of data on tree rings.

Study Identifies Key T Cells for Immunity Against Fungal Pneumonia

 GM-CSF+ and IL-17A+ lineages of T cells are instrumental in controlling many fungal and bacterial infections and implicated in autoimmune pathology. This study shows that GM-CSF expressing Tc17 cells are necessary for mediating fungal vaccine immunity without augmenting pathology.
Credit: Som Nanjappa

Researchers at the University of Illinois College of Veterinary Medicine have demonstrated in a mouse model that a specific type of T cell, one of the body’s potent immune defenses, produces cytokines that are necessary for the body to acquire immunity against fungal pathogens. This finding could be instrumental in developing novel, effective fungal vaccines.

Despite vaccines being hailed as one of the greatest achievements of medicine, responsible for controlling or eradicating numerous life-threatening infectious diseases, no vaccines have been licensed to prevent or control human fungal infections.

This lack proved especially deadly during the COVID-19 pandemic. In countries where steroids were widely used to suppress inflammation of the lungs, COVID-19 patients with preexisting conditions such as uncontrolled diabetes showed a greater likelihood of developing lethal fungal infections.

Researchers create the first quasiparticle Bose-Einstein condensate

Observation of Bose-Einstein condensates of excitons in a bulk semiconductor using mid-infrared induced absorption imaging realized in a dilution refrigerator A close-up picture of the apparatus in a cryogen-free dilution refrigerator. A dark red-colored cubic crystal in the center of the picture is cuprous oxide. A zinc selenide meniscus lens placed behind the crystal is an objective lens. A rod and a stage below the crystal is used for generation of an inhomogeneous strain field in the crystal that acts as a trap potential for excitons.
Credit: ©2022 Yusuke Morita, Kosuke Yoshioka and Makoto Kuwata-Gonokami, The University of Tokyo

Physicists have created the first Bose-Einstein condensate — the mysterious “fifth state” of matter — made from quasiparticles, entities that do not count as elementary particles but that can still have elementary-particle properties like charge and spin. For decades, it was unknown whether they could undergo Bose-Einstein condensation in the same way as real particles, and it now appears that they can. The finding is set to have a significant impact on the development of quantum technologies including quantum computing.

A paper describing the process of creation of the substance, achieved at temperatures a hair’s breadth from absolute zero, was published in the journal Nature Communications.

Bose-Einstein condensates are sometimes described as the fifth state of matter, alongside solids, liquids, gases and plasmas. Theoretically predicted in the early 20th century, Bose-Einstein condensates, or BECs, were only created in a lab as recently as 1995. They are also perhaps the oddest state of matter, with a great deal about them remaining unknown to science.

Autistic people are more likely to experience depression and anxiety during pregnancy

Credit: PetraSolajova

Autistic people are more vulnerable to depression and anxiety during pregnancy, according to new research from the University of Cambridge. The results are published in the Journal of Autism and Developmental Disorders and have important implications for supporting autistic people during pregnancy.

In the study, led by researchers at the Autism Research Centre, 524 non-autistic people and 417 autistic people completed an online survey about their experience of pregnancy. Anyone who was pregnant at the time of responding or had previously given birth was eligible to take part.

The study revealed that autistic parents were around three times more likely than non-autistic parents to report having experienced prenatal depression (9% of non-autistic parents and 24% of autistic parents) and anxiety (14% of non-autistic parents and 48% of autistic parents).

Autistic respondents also experienced lower satisfaction with pregnancy healthcare. Autistic respondents were less likely to trust professionals, feel that professionals took their questions and concerns seriously, feel that professionals treated them respectfully, and be satisfied with how information was presented to them in appointments. Furthermore, autistic respondents were more likely to experience sensory issues during pregnancy and more likely to feel overwhelmed by the sensory environment of prenatal appointments.

Municipal building regulations inhibit the expansion of renewable energies

Solar systems change the townscape. That can be problematic.
Credit: Solarimo

Municipalities with high legal requirements for the construction of photovoltaic systems have been shown to produce less solar power.

Securing energy supplies, coping with climate change and expanding renewable energies are high priorities in Germany. However, municipalities often pursue their own goals: municipal building regulations in particular, for example to protect the historical townscape, conflict with the expansion of renewable energies. A research team led by Prof. Dr. Stefano Carattini, professor of economics at Georgia State University, Atlanta, USA, and Prof. Dr. Andreas Löschel, professor for environmental / resource economics and sustainability at the Ruhr University Bochum, examines. The study shows that many municipalities have issued building regulations that regulate the installation of photovoltaic systems. These communities have 10.4 percent less solar power than communities in the comparison group. The study is on 24. October 2022 published as a CESifo working paper in Munich.

In Germany, the Renewable Energy Sources Act and the resulting increase in solar systems in the past two decades have made a decisive contribution to greatly reducing the price of solar power. As a result, the share of renewable energies in the energy mix has increased significantly. "However, the expansion goals are immense and clearly exceed the historical trend," says Andreas Löschel. “In our current study, we are researching for the first time whether building law requirements, in particular building design law, represent a decisive obstacle to the expansion of solar energy."

Monday, October 24, 2022

Study looks inside the brain during sleep to show how memory is stored


MRI scans showing locations of medial-temporal electrodes in a representative patient.
Source/Credit: Department of Neurological Surgery, The University of Chicago.

A new study looks deep inside the brain, where previous learning was reactivated during sleep, resulting in improved memory.

Neuroscientists from Northwestern University teamed up with clinicians from the University of Chicago Epilepsy Center to study the brain electrical activity in five of the center’s patients in response to sounds administered by the research team as part of a learning exercise.

The five patients who volunteered to participate in the study had electrode probes implanted into the brain for the purpose of investigating potential treatments for their seizure disorders.

While prior studies have used EEG recordings captured by electrodes on the head to measure memory processing during sleep, this is the first study to record such electrical activity from inside the brain.

The study found participants significantly improved their performance in a recall test the next morning. The mapped brain activity allowed the researchers to take a big step forward in understanding how memory storage works by providing visual data identifying the areas of the brain engaged in the process of overnight memory storage.

Molecular cage protects precious metals in catalytic converters

Stable catalyst illustration
Source/Credit: Slac National Accelerator Laboratory

Sometimes, solutions to environmental problems can have environmentally unfriendly side effects. For example, while most gas-powered cars have a catalytic converter that transforms engine emission pollutants into less harmful gases, this comes with a tradeoff: Catalytic converters contain precious metals such as platinum and palladium.

The good thing about these precious metals is that they act as catalysts that help break down pollutants, with a suite of properties that make them the best elemental candidates for this chemical job. But they are also rare, which makes them expensive, and extracting them from the earth produces its own pollution.

However, in a paper published October 24 in Nature Materials, researchers at the SUNCAT Center for Interface Science and Catalysis and the Precourt Institute for Energy at Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory reported a way of encapsulating catalysts that could reduce the number of precious metals catalytic converters need to work, which could in turn reduce the practice of precious metal mining.

“I think the material we made could knock down the number of precious metals used in a catalytic converter by 50 precent, which would mean a lot once you multiply that by the nearly 1.5 billion cars we now have in circulation on the planet,” said Matteo Cargnello, the new study's senior author and an assistant professor of chemical engineering at Stanford University.

Gestational Exposure to Flame Retardant Alters Brain Development in Rats

A new study from North Carolina State University shows that exposure in utero to the flame retardant FireMaster® 550 (FM 550), or to its individual brominated (BFR) or organophosphate ester (OPFR) components, resulted in altered brain development in newborn rats. The effects – most notably evidence of mitochondrial disruption and dysregulated choline and triglyceride levels in brain tissue – were greater in male offspring than in females. The work adds to the body of evidence that both OPFRs and BFRs can be neurotoxic.

FM 550 is a flame-retardant mixture first identified a decade ago. It was developed to replace PBDEs, a class of fire retardants being phased out due to safety concerns.

“While some new flame-retardant mixtures still contain BFRs, the OPFRs are a popular substitute for PBDEs, since it is believed that OPFRs don’t accumulate in the body and thus cannot be as harmful,” says Heather Patisaul, associate dean for research in NC State’s College of Sciences and corresponding author of the study. “Specifically, it was thought that OPFRs wouldn’t impact acetylcholinesterase – a key neurotransmitter. But it looks as though OPFRs still impact choline signaling and are just as bad if not worse than PBDEs for the developing brain.”

Patisaul and her colleagues performed transcriptomic and lipidomic studies on the prefrontal cortexes of newborn rats whose mothers had been exposed to FM550, or to BFR or OPFR elements individually, during gestation.

High-tech sensors could guide vehicles without satellites, if they can handle the ride

Sandia National Laboratories atomic physicist Jongmin Lee examines the sensor head of a cold-atom interferometer that could help vehicles stay on course where GPS is unavailable.
Photo credit: Bret Latter

Words like “tough” or “rugged” are rarely associated with a quantum inertial sensor. The remarkable scientific instrument can measure motion a thousand times more accurately than the devices that help navigate today’s missiles, aircraft and drones. But its delicate, table-sized array of components that includes a complex laser and vacuum system has largely kept the technology grounded and confined to the controlled settings of a lab.

Jongmin Lee wants to change that.

The atomic physicist is part of a team at Sandia National Laboratories that envisions quantum inertial sensors as revolutionary, onboard navigational aids. If the team can reengineer the sensor into a compact, rugged device, the technology could safely guide vehicles where GPS signals are jammed or lost.

In a major milestone toward realizing their vision, the team has successfully built a cold-atom interferometer, a core component of quantum sensors, designed to be much smaller and tougher than typical lab setups. The team describes their prototype in the academic journal Nature Communications, showing how to integrate several normally separated components into a single monolithic structure. In doing so, they reduced the key components of a system that existed on a large optical table down to a sturdy package roughly the size of a shoebox.

Microscopy reveals how psychedelics light up brain’s neuropathways

 Alex Kwan, Ph.D. ‘09, associate professor in the Meinig School of Biomedical Engineering, is using optical microscopy and other tools to map the brain’s neural response to psychedelic drugs, an approach that could lead to the development of fast-acting antidepressants
Photo credit: Ryan Young/Cornell University.

What a long, strange trip it’s been for psychedelic drugs. From their use in ancient indigenous ceremonies, to their often-caricatured association with the 1960s counterculture, to their recent reemergence as a potential therapeutic, hallucinogens have been embraced by very different communities for very different reasons. But scientists have never fully understood how these drugs actually work on the brain.

Alex Kwan, Ph.D. ‘09, associate professor in the Meinig School of Biomedical Engineering in the College of Engineering, is using optical microscopy and other tools to map the brain’s neural response to these psychoactive chemicals, an approach that could eventually lead to the development of fast-acting antidepressants and treatments for substance-use disorders and cluster headaches.

“We know more about the pharmacology, how psychedelics work at the structural level, interacting with the brain receptors. But there has been a big void in terms of understanding what they do to the brain itself, at the neural circuit level,” Kwan said. “There’s a chain of events that happen that ultimately lead to acute and longer-lasting behavioral changes that might be useful for treatment. But in between a lot of that is a black box.”

Despite the renewed interest in the benefits of psychedelics from popular figures such as environmentalist and author Michael Pollan, much of the research into these drugs was conducted in the 1950s and 60s with fairly rudimentary methods, Kwan said.

Penguin feathers may be secret to effective anti-icing technology

Gentoo penguins
Photo Credit: 66 north

Ice buildup on powerlines and electric towers brought the northern US and southern Canada to a standstill during the Great Ice Storm of 1998, leaving many in the cold and dark for days and even weeks. Whether it is on wind turbines, electric towers, drones, or airplane wings, dealing with ice buildup typically depends on techniques that are time consuming, costly and/or use a lot of energy, along with various chemicals. But, by looking to nature, McGill researchers believe that they have found a promising new way of dealing with the problem. Their inspiration came from the wings of Gentoo penguins who swim in the ice-cold waters of the south polar region, with pelts that remain ice-free even when the outer surface temperature is well below freezing.

We initially explored the qualities of the lotus leaf, which is very good at shedding water but proved less effective at shedding ice,” said Anne Kietzig, who has been looking for a solution for close to a decade. She is an associate professor in Chemical Engineering at McGill and the director of the Biomimetic Surface Engineering Laboratory. “It was only when we started investigating the qualities of penguin feathers that we discovered a material found in nature that was able to shed both water and ice.”

Sand serves up a possible cure for obesity

Engineered particles of purified sand could be the next anti-obesity therapy as new research from the University of South Australia published in journal MPDI Pharmaceutics shows that porous silica can prevent fats and carbohydrates from being adsorbed in the body.

The engineered silica particles are made from purified sand and are optimally designed with a high surface area that enables them to soak up large amounts of digestive enzymes, fats, and sugars within the gastrointestinal tract.

Funded by the Channel 7 Children’s Research Foundation, the study is the first to validate how porous silica particles can impede digestive processes and stop fat and sugar adsorption.

Developed in partnership with Glantreo Limited, the new silica-based therapy will be gentler on the stomach with fewer of the unpleasant side effects associated with the mainstream anti-obesity drug, Orlistat.

Lead researcher, UniSA’s Dr Paul Joyce says this breakthrough finding could change the health outcomes for billions of people struggling with obesity.

More yield, fewer species: How human nutrient intakes alter grasslands

Credit: Pete Linforth

High nutrient inputs in grassland lead to more plant species being lost than new ones can establish over longer periods of time. In addition, fewer new species settle than under natural nutrient availability. A worldwide experiment led by the German Centre for Integrative Biodiversity Research (iDiv), the Helmholtz Centre for Environmental Research (UFZ) and the Martin Luther University Halle-Wittenberg (MLU) has now been able to show why additional nutrient inputs reduce plant diversity in grasslands. The study published in "Ecology Letters", also sheds light on another issue: The increase in biomass with nutrient inputs is due to a few plant species that can use higher nutrient inputs to their advantage and remain successfully at a site over long periods of time.

One of the reasons for the global threat to biodiversity is that we humans introduce more nutrients into our environment than would naturally be present there, for example, when fertilizing agricultural land. In addition, precipitation re-distributes excess nutrients to other areas, and nutrients can also enter our soil through air pollution.

Natural grasslands are a habitat for many different plant species including grasses, herbs, wildflowers and orchids, many of which can be threatened by human activities and impacts. Plants need three things to grow: carbon dioxide (CO2) from the air, water and nutrients from the soil. The latter are usually scarce in semi-natural European meadows. Although this limits the growth of individual plants, it Favours the possibility of many different species growing side by side. Excessive amounts of nutrients, however, create the image that is ubiquitous in our landscape today: lush green meadows but without the colorful flowers of former times.

Mild thyroid disorders can cause serious heart problems

Johannes W. Dietrich works in the section diabetology, endocrinology and metabolism of Medical Clinic I in the RUB Clinic St. Josef Hospital.
Credit: Curtesy of Johannes W. Dietrich

A systematic evaluation of 32 studies with 1.3 million participants reveals new relationships.

It has been known for more than 200 years that severe over functions of the thyroid gland can lead to disturbances in the heart rhythm and thus to sudden cardiac death. So far, it has been unclear what risk is associated with only slight over- or under-functions. A systematic evaluation of 32 studies with 1.3 million participants shows that even slight deviations in thyroid function can increase the risk of serious cardiovascular diseases. "This puts our understanding of the interaction between the thyroid and the heart on a new footing and shows the way to personalized prevention," said private lecturer Dr. Johannes Dietrich from the medical clinic in St. Josef Hospital, Clinic of the Ruhr University Bochum (RUB). The researchers worked in the journal Frontiers in Cardiovascular Medicine.

For the work, the cardiac and hormone researchers of the RUB cooperated with the Tan Tock Seng Hospital, the Lee Kong Chian School of Medicine and the Duke-NUS Medical School in Singapore.

Scientists Created a Material Promising for Improving Brightness of Screens

One of the assembled organic LEDs based on push-pull systems.
Photo credit: Ruslan Gadirov / TSU

Scientists at the Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, and Ural Federal University have developed, synthesized, and studied a series of new fluorophores - push-pull systems (compounds with pronounced electron-donor and electron-acceptor parts) based on cyanopyrazine. Ural chemists in cooperation with colleagues from Tomsk State University showed that the presence of a cyano group in the substance significantly increases the efficiency of organic light emitting diodes (OLEDs) based on it. This opens the prospect of creating new materials to enhance the brightness of displays of smartphones, computers and televisions. An article describing the research and its results was published in the journal Dyes and Pigments.

In previous research work, chemists demonstrated that one of the most promising compounds as an acceptor (attracting electrons) part in push-pull systems is the pyrazine ring (another name is 1,4-diazine), a compound of nitrogen, hydrogen and carbon that has a significant electron-accepting effect.

A revolutionary method to observe cell transport

Nanobodies (grey) with magnetic probes (red stars) target the desired membrane protein.
Credit: Bordignon, Enrica

Membrane proteins are key targets for many drugs. They are located between the outside and inside of our cells. Some of them, called ‘‘transporters’’, move certain substances in and out of the cellular environment. Yet, extracting and storing them for observation is particularly complex. A team from the University of Geneva (UNIGE), in collaboration with the University of Zurich (UZH), has developed an innovative method to study their structure in their native environment: the cell. The technique is based on electron spin resonance spectroscopy. These results, just published in the journal Science Advances, may facilitate future development of new drugs.

In living organisms, each cell is surrounded by a cell membrane (or ‘‘cytoplasmic membrane’’). This membrane consists of a double layer of lipids. It separates the contents of the cell from its direct environment and regulates the substances that can enter or leave the cell. The proteins attached to this membrane are called ‘‘membrane proteins’’.

Located at the interface between the outside and inside of the cell, they carry various substances across the membrane - into or out of the cell - and play a crucial role in cell signaling, i.e. in the communication system of cells that allows them to coordinate their metabolic processes, development and organization. As a result, membrane proteins represent more than 60% of current drug targets.

Using Carbon-Carbon Clumping to Detect the Signature of Biotic Hydrocarbons

The mystery of the origin of hydrocarbons found in extraterrestrial environment may finally be resolved, thanks to a technique developed by researchers at Tokyo Tech based on a 13C-13C abundance analysis. By measuring the abundance of clumped 13C-13C isotope in the hydrocarbons, it can be inferred if a hydrocarbon was produced via biological processes. This could open doors to distinguishing such hydrocarbons from abiotic ones, aiding our search for extra-terrestrial life.

An important signature of life is the existence of organic molecules that have originated from biological processes. The most common organic molecule found in all life forms are hydrocarbons. However, they need not be of biotic origin, i.e., produced from thermal decomposition of sedimentary organic matter or microbes. So, while hydrocarbons have been found in several places outside Earth, they are not necessarily indicative of extra-terrestrial life. These hydrocarbons could well have formed from abiotic, or non-biological processes. Therefore, finding out whether a hydrocarbon is of biotic or abiotic origin is key to inferring the existence of life. Unfortunately, this has proved to be a tremendously challenging task so far.

How heart failure disrupts the cell’s powerhouse

From left: Shingo Takada, Hokkaido University and Hokusho University; Shintaro Kinugawa, Kyushu University; and Hisataka Sabe, Hokkaido University
Photos credits: Shingo Takada, Shintaro Kinugawa, Hisataka Sabe

Chronic heart failure causes the cell’s powerhouses to dysfunction, in part due to overconsumption of an important intermediary compound in energy production. Supplementing the diet to compensate for this could prove a promising strategy for treating heart failure. The findings were published in the journal PNAS by Hokkaido University scientists and colleagues in Japan.

Mitochondria are small organelles found in almost every cell and are responsible for converting carbohydrates, fats and proteins into energy to power biochemical reactions. Chronic heart failure is known to be associated with mitochondrial dysfunction, but much is still unknown about how this happens at the molecular level.

A research team consisting of molecular biologist Hisataka Sabe (Hokkaido University), cardiovascular medicine specialists Shingo Takada (Hokkaido University and Hokusho University) and Shintaro Kinugawa (Kyushu University) and their colleagues studied the biochemical processes that occur in mice with chronic heart failure caused by surgically blocking part of the blood supply to their hearts. They specifically looked at heart cells outside the boundaries of dead tissue.