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Category Archives: Mind Building
Fossilized slime of 100-million-year-old hagfish shakes up vertebrate family tree
Paleontologists at the University of Chicago have discovered the first detailed fossil of a hagfish, the slimy, eel-like carrion feeders of the ocean. The 100-million-year-old fossil helps answer questions about when these ancient, jawless fish branched off the evolutionary tree from the lineage that gave rise to modern-day jawed vertebrates, including bony fish and humans.
The fossil, named Tethymyxine tapirostrum,is a 12-inch long fish embedded in a slab of Cretaceous period limestone from Lebanon. It fills a 100-million-year gap in the fossil record and shows that hagfish are more closely related to the blood-sucking lamprey than to other fishes. This means that both hagfish and lampreys evolved their eel-like body shape and strange feeding systems after they branched off from the rest of the vertebrate line of ancestry about 500 million years ago.
“This is a major reorganization of the family tree of all fish and their descendants. This allows us to put an evolutionary date on unique traits that set hagfish apart from all other animals,” said Tetsuto Miyashita, PhD, a Chicago Fellow in the Department of Organismal Biology and Anatomy at UChicago who led the research. The findings are published this week in the Proceedings of the National Academy of Sciences.
The slimy dead giveaway
Modern-day hagfish are known for their bizarre, nightmarish appearance and unique defense mechanism. They don’t have eyes, or jaws or teeth to bite with, but instead use a spiky tongue-like apparatus to rasp flesh off dead fish and whales at the bottom of the ocean. When harassed, they can instantly turn the water around them into a cloud of slime, clogging the gills of would-be predators.
This ability to produce slime is what gave away the Tethymyxine fossil. Miyashita used an imaging technology called synchrotron scanning at Stanford University to identify chemical traces of soft tissue that were left behind in the limestone when the hagfish fossilized. These soft tissues are rarely preserved, which is why there are so few examples of ancient hagfish relatives to study.
The scanning picked up a signal for keratin, the same material that makes up fingernails in humans. Keratin, as it turns out, is a crucial part of what makes the hagfish slime defense so effective. Hagfish have a series of glands along their bodies that produce tiny packets of tightly-coiled keratin fibers, lubricated by mucus-y goo. When these packets hit seawater, the fibers explode and trap the water within, turning everything into shark-choking slop. The fibers are so strong that when dried out they resemble silk threads; they’re even being studied as possible biosynthetic fibers to make clothes and other materials.
Miyashita and his colleagues found more than a hundred concentrations of keratin along the body of the fossil, meaning that the ancient hagfish probably evolved its slime defense when the seas included fearsome predators such as plesiosaurs and ichthyosaurs that we no longer see today.
“We now have a fossil that can push back the origin of the hagfish-like body plan by hundreds of millions of years,” Miyashita said. “Now, the next question is how this changes our view of the relationships between all these early fish lineages.”
Shaking up the vertebrate family tree
Features of the new fossil help place hagfish and their relatives on the vertebrate family tree. In the past, scientists have disagreed about where they belonged, depending on how they tackled the question. Those who rely on fossil evidence alone tend to conclude that hagfish are so primitive that they are not even vertebrates. This implies that all fishes and their vertebrate descendants had a common ancestor that — more or less — looked like a hagfish.
But those who work with genetic data argue that hagfish and lampreys are more closely related to each other. This suggests that modern hagfish and lampreys are the odd ones out in the family tree of vertebrates. In that case, the primitive appearance of hagfish and lampreys is deceptive, and the common ancestor of all vertebrates was probably something more conventionally fish-like.
Miyashita’s work reconciles these two approaches, using physical evidence of the animal’s anatomy from the fossil to come to the same conclusion as the geneticists: that the hagfish and lampreys should be grouped separately from the rest of fishes.
“In a sense, this resets the agenda of how we understand these animals,” said Michael Coates, PhD, professor of organismal biology and anatomy at UChicago and a co-author of the new study. “Now we have this important corroboration that they are a group apart. Although they’re still part of vertebrate biodiversity, we now have to look at hagfish and lampreys more carefully, and recognize their apparent primitiveness as a specialized condition.
Paleontologists have increasingly used sophisticated imaging techniques in the past few years, but Miyashita’s research is one of a handful so far to use synchrotron scanning to identify chemical elements in a fossil. While it was crucial to detect anatomical structures in the hagfish fossil, he believes it can also be a useful tool to help scientists detect paint or glue used to embellish a fossil or even outright forge a specimen. Any attempt to spice up a fossil specimen leaves chemical fingerprints that light up like holiday decorations in a synchrotron scan.
“I’m impressed with what Tetsuto has marshaled here,” Coates said. “He’s maxed out all the different techniques and approaches that can be applied to this fossil to extract information from it, to understand it and to check it thoroughly.”
Greenland ice melting four times faster than in 2003
Greenland is melting faster than scientists previously thought — and will likely lead to faster sea level rise — thanks to the continued, accelerating warming of the Earth’s atmosphere, a new study has found.
Scientists concerned about sea level rise have long focused on Greenland’s southeast and northwest regions, where large glaciers stream iceberg-sized chunks of ice into the Atlantic Ocean. Those chunks float away, eventually melting. But a new study published Jan. 21 in the Proceedings of the National Academy of Sciences found that the largest sustained ice loss from early 2003 to mid-2013 came from Greenland’s southwest region, which is mostly devoid of large glaciers.
“Whatever this was, it couldn’t be explained by glaciers, because there aren’t many there,” said Michael Bevis, lead author of the paper, Ohio Eminent Scholar and a professor of geodynamics at The Ohio State University. “It had to be the surface mass — the ice was melting inland from the coastline.”
That melting, which Bevis and his co-authors believe is largely caused by global warming, means that in the southwestern part of Greenland, growing rivers of water are streaming into the ocean during summer. The key finding from their study: Southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise.
“We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers,” he said. “But now we recognize a second serious problem: Increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea.”
The findings could have serious implications for coastal U.S. cities, including New York and Miami, as well as island nations that are particularly vulnerable to rising sea levels.
And there is no turning back, Bevis said.
“The only thing we can do is adapt and mitigate further global warming — it’s too late for there to be no effect,” he said. “This is going to cause additional sea level rise. We are watching the ice sheet hit a tipping point.”
Climate scientists and glaciologists have been monitoring the Greenland ice sheet as a whole since 2002, when NASA and Germany joined forces to launch GRACE. GRACE stands for Gravity Recovery and Climate Experiment, and involves twin satellites that measure ice loss across Greenland. Data from these satellites showed that between 2002 and 2016, Greenland lost approximately 280 gigatons of ice per year, equivalent to 0.03 inches of sea level rise each year. But the rate of ice loss across the island was far from steady.
Bevis’ team used data from GRACE and from GPS stations scattered around Greenland’s coast to identify changes in ice mass. The patterns they found show an alarming trend — by 2012, ice was being lost at nearly four times the rate that prevailed in 2003. The biggest surprise: This acceleration was focused in southwest Greenland, a part of the island that previously hadn’t been known to be losing ice that rapidly.
Bevis said a natural weather phenomenon — the North Atlantic Oscillation, which brings warmer air to West Greenland, as well as clearer skies and more solar radiation — was building on man-made climate change to cause unprecedented levels of melting and runoff. Global atmospheric warming enhances summertime melting, especially in the southwest. The North Atlantic Oscillation is a natural — if erratic — cycle that causes ice to melt under normal circumstances. When combined with man-made global warming, though, the effects are supercharged.
“These oscillations have been happening forever,” Bevis said. “So why only now are they causing this massive melt? It’s because the atmosphere is, at its baseline, warmer. The transient warming driven by the North Atlantic Oscillation was riding on top of more sustained, global warming.”
Bevis likened the melting of Greenland’s ice to coral bleaching: Once the ocean’s water hits a certain temperature, coral in that region begins to bleach. There have been three global coral bleaching events. The first was caused by the 1997-98 El Niño, and the other two events by the two subsequent El Niños. But El Niño cycles have been happening for thousands of years — so why have they caused global coral bleaching only since 1997?
“What’s happening is sea surface temperature in the tropics is going up; shallow water gets warmer and the air gets warmer,” Bevis said. “The water temperature fluctuations driven by an El Niño are riding this global ocean warming. Because of climate change, the base temperature is already close to the critical temperature at which coral bleaches, so an El Niño pushes the temperature over the critical threshold value. And in the case of Greenland, global warming has brought summertime temperatures in a significant portion of Greenland close to the melting point, and the North Atlantic Oscillation has provided the extra push that caused large areas of ice to melt.”
Before this study, scientists understood Greenland to be one of the Earth’s major contributors to sea-level rise — mostly because of its glaciers. But these new findings, Bevis said, show that scientists need to be watching the island’s snowpack and ice fields more closely, especially in and near southwest Greenland.
GPS systems in place now monitor Greenland’s ice margin sheet around most of its perimeter, but the network is very sparse in the southwest, so it is necessary to densify the network there, given these new findings.
“We’re going to see faster and faster sea level rise for the foreseeable future,” Bevis said. “Once you hit that tipping point, the only question is: How severe does it get?”
Energizing the immune system to eat cancer
Immune cells called macrophages are supposed to serve and protect, but cancer has found ways to put them to sleep. Now researchers at the Abramson Cancer Center of the University of Pennsylvania say they’ve identified how to fuel macrophages with the energy needed to attack and eat cancer cells. It is well established that macrophages can either support cancer cell growth and spread or hinder it. But most tumors also express a signal called CD47, which can lull macrophages into a deep sleep and prevent them from eating. Researchers have found that rewiring macrophage metabolism can overcome this signal and act like an alarm clock to rouse and prepare macrophages to go to work. Their findings were published in Nature Immunology today.
Macrophages are immune cells just like T and B cells, but differ in that they can eat cells that are not supposed to be in the body. In fact, they are the most prominent immune cell found in cancer, but unfortunately, most are often convinced to help cancer grow and spread. Cancer cells frequently stop macrophages from attacking them by expressing CD47, a “don’t eat me” signal. Researchers now say that merely blocking inhibitory signals like CD47 is not always sufficient to convince macrophages to attack cancer. Instead, two signals are required. First, they need a signal to activate them — such as a toll-like receptor agonist. After that, a second signal — such as a CD47 inhibitor — can lower the threshold needed to wage battle on the cancer.
“It turns out macrophages need to be primed before they can go to work, which explains why solid tumors may resist treatment with CD47 inhibitors alone,” said the study’s senior author Gregory L. Beatty, MD, PhD, an assistant professor of Hematology-Oncology at Penn’s Perelman School of Medicine. Jason Mingen Liu, an MD and PhD graduate student in Beatty’s lab, is the study’s lead author.
The team used this approach by activating macrophages with CpG, a toll-like receptor agonist that sends the first signal, and found that it rapidly induced shrinkage of tumors and prolonged survival of mice even without the requirement of T cells. Unexpectedly, they also found that the activated macrophages were able to eat cancer cells even in the presence of high levels of CD47.
To understand the molecular basis of this phenomenon, the team traced the metabolic activity of macrophages and determined that activated macrophages began to utilize both glutamine and glucose as fuel to support the energy requirements needed for them to eat cancer cells. This rewiring of the macrophages metabolism was necessary for CpG to be effective, and the researchers say these findings point to the importance of macrophage metabolism in determining the outcome of an immune response.
“Cancer does not shrink without the help of macrophages and macrophages need the right fuel to eat cancer cells and shrink tumors,” Liu said. “To do this, a shift in metabolism is needed to steer the energy in the right direction. It is the metabolism that ultimately allows macrophages to override signals telling them not to do their job.”
Beatty points out that patients with diabetes, cardiovascular disease, and other conditions are routinely treated with drugs that could affect macrophage metabolism, but virtually nothing is known about how these drugs might impact immunotherapy responses in cancer, meaning the team’s discovery has implications even for existing treatments.
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Materials provided by University of Pennsylvania School of Medicine. Note: Content may be edited for style and length.
He Jiankui: China condemns ‘baby gene editing’ scientist
Investigators say He Jiankui sought “fame and fortune” with his claim to have edited baby genes.
Health24.com | Breastfeeding isn’t just good for the baby – it may help a mom’s heart
Studies have long touted the benefits of breastfeeding for infants, including stronger immune systems and lower risk for asthma, obesity and type 2 diabetes.
But babies aren’t the only ones benefiting: Nursing also appears to provide health benefits for moms.
Research suggests women who breastfeed have a lower risk of breast and ovarian cancers. The longer women nurse, whether with one child or over the course of several, the lower their risk.
Release of oxytocin
More recently, studies have found that breastfeeding also helps the mother’s heart – beyond nurturing its bond with baby, that is.
Breastfeeding has been associated with a lower risk of developing diabetes, high cholesterol, high blood pressure and heart disease.
But the mechanics behind how that might happen is up for debate.
It’s possibly linked to the release of the hormone oxytocin, which relaxes blood vessels, said Dr Nieca Goldberg, medical director of the Joan H. Tisch Center for Women’s Health at New York University.
“It may also very well be that many breastfeeding mothers have a healthier lifestyle overall,” she said.
These women may eat healthier, exercise regularly and “they make healthier choices in general, not only for their babies but themselves,” she said.
Another theory stems from the large number of calories burned from breastfeeding.
Jury still out
A 2017 study published in the Journal of the American Heart Association found nursing may help mothers lower their risk of heart attack and stroke long after giving birth. The study didn’t explain the reason behind the link, but researchers noted that breastfeeding helps women lose pregnancy-related weight, including fat reserves that help fuel foetal growth. This process may help “reset” the body’s metabolism after giving birth.
But for the most part, Goldberg said, “the jury is still out on the specific reasons why breastfeeding lowers risk for heart disease.”
None of the research suggests that women who can’t or choose not to breastfeed are more likely to develop heart issues, Goldberg said.
“There are many other things you can do to improve your heart health,” she said. “Think about it, every time you take your baby for a walk, you’re exercising yourself, too.”
A 2018 report from the Centers for Disease Control and Prevention found that four out of five babies are breastfed after birth, although only half of all infants are still breastfed at six months.
The American Academy of Pediatrics recommends exclusive breastfeeding for the first six months, then continued nursing with the introduction of foods through the rest of the first year and thereafter for as long as mother and baby desire.
Lifestyle decisions
For women who don’t know whether they want to breastfeed, just knowing the option may improve their heart health could tip the scale, said Dr Lisa Hollier, president of the American College of Obstetricians and Gynecologists.
It could be especially appealing for women who develop pregnancy complications such as preeclampsia or gestational diabetes, since those conditions can mean a significantly increased lifetime risk of cardiovascular disease.
“Breastfeeding would be beneficial for these women,” said Hollier, chief medical officer for obstetrics and gynaecology at Texas Children’s Health Plan in Houston. “Our counselling of women after delivery following this type of pregnancy complication really should include information about the protective association between breastfeeding and metabolic disease and cardiovascular disease.”
Women should still make healthy lifestyle decisions to reduce their risk, such as eating healthy, exercising regularly and reducing stress, Hollier said.
“But if you were on the fence about breastfeeding,” she said, “this is just one other thing that would add to your decision.”
Image creddit: iStock
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Health24.com | How getting a flu shot could save your life
It’s not too late to get your flu shot, which can protect you in ways that may surprise you.
The flu vaccine can be a lifesaver for people with heart disease, according to infectious disease specialist Dr Michael Chang, assistant professor of paediatrics at University of Texas Health Science Center at Houston.
A no-brainer
“Previous studies have shown influenza vaccination could reduce death, acute coronary syndromes, and hospitalisation in patients with coronary heart disease, and/or heart failure,” Chang said in a university news release.
“This makes getting your flu shot a no-brainer for anyone with a history of heart disease. It’s an extremely cost-effective intervention with lifesaving potential,” he said.
The flu shot can also protect you from other nasty infections.
“Your immunity can be altered by having flu, making you more prone to other infections, particularly in the respiratory tract where cells have been damaged. Staph infections are common and mainly not serious, but if you have flu already, Staphylococcus aureus can enter the lungs, causing pneumonia,” Chang said.
‘Super spreaders’
“That explains why this type of bacterial coinfection is frequent in influenza-associated pneumonia,” he said, noting that patients with more than one infection have higher odds for complications and death.
It’s not just important for adults to get a flu shot. Having kids vaccinated protects their grandparents and other elderly people, who are at high risk from the flu.
“Children have been described as ‘super spreaders’ because they come into close contact with family members, and younger ones tend to put their hands in their mouths more, which can put others at greater risk, especially older family members,” Chang said.
Children under five years are especially vulnerable. Fortunately, the nasal flu spray has returned this year, which should make it easier for little ones who don’t like injections, Chang said. Studies show it is just as effective as the shot.
Last year’s flu season was the worst in four decades, with more than 80 000 flu or pneumonia-related deaths in the United States.
Image credit: iStock
Health24.com | 5 everyday things people think cause cancer but don’t
Over the years, we’ve heard that plastic bottles, our car’s air conditioning and microwaving plastic containers cause cancer.
But don’t believe everything you read. Research shows that these are myths. We uncovered five everyday things people think cause cancer but actually don’t.
1. Plastic bottles
The claim: In the 2000s, an email circulated that read, “Many are unaware of poisoning caused by re-using plastic bottles … bottles are safe for one-time use only; if you must keep them longer, it should be for no more than a few days, a week max, and keep them away from heat as well.” It went on to explain that plastic bottles contain a potentially carcinogenic substance called diethylhexyl adipate (DEHA).
The truth: The American Cancer Society says these emails were apparently based on a student’s thesis. They say, “DEHA is not inherent in the plastic used to make these bottles.” Even if it was, however, according to the US Environmental Protection Agency, DEHA “cannot reasonably be anticipated to cause cancer; teratogenic effects; immunotoxicity, neurotoxicity; gene mutations; liver, kidney, reproductive, or developmental toxicity; or other serious or irreversible chronic health effects”. The International Agency for Research on Cancer adds that DEHA “is not classifiable as to its carcinogenicity to humans”.
Bisphenol A (or BPA) found in plastic does not pose a health risk either. Cancer Research UK says, “There is no good evidence that BPA can cause cancer in people. The European Food Safety Authority did a full scientific review and concluded there was no health risk.”
If you’re still unsure, then use a glass bottle – it’s more environmentally friendly anyway.
2. Microwaving plastic containers
The claim: An email was circulated where Dr Fujimoto from Castle Hospital warned that heating plastic in the microwave (or freezing water in plastic bottles) could release dangerous toxins, such as dioxin and DEHA. In August 2004, the email continued to do the rounds, this time with the name of an American Cancer Society staffer attached to it, which gave the hoax claim more credibility.
The truth: According to the US Food and Drug Administration (FDA), substances that are used to make plastics can leach into foods. However, they also found that the levels expected to transfer from the plastic into foods is within the margin of safety based on the information they have. The FDA adds that it “has seen no evidence that plastic containers or films contain dioxins, and knows of no reason why they would”.
In terms of personal safety, only use containers that are labelled as microwave safe – if they are not, the plastic could melt. According to Harvard Health Publishing, most takeaway containers, water bottles, plastic tubs or jars made to hold margarine, yoghurt, cream cheese, mayonnaise and mustard are not suitable for heating in the microwave.
3. Underwire bras
The claim: In 1995 Ross Singer and Soma Grismaijer, a husband and wife medical anthropologist team, published a book called Dressed to Kill. The Scientific American reports that in this book they claim that women who wear tight-fitting bras every day are at a higher risk of developing breast cancer. Singer and Grismaijer said “by inhibiting lymphatic drainage, bras trap toxins in the breast tissue, which causes cancer”.
The truth: There is only one scientific study looking at the link between wearing a bra and breast cancer, and it found no difference between wearing a bra or not. The research was published online in 2014 by Cancer Epidemiology Biomarkers & Prevention.
Lu Chen, public health sciences researcher at the Fred Hutchinson Cancer Research Center, said, “Our study found no evidence that wearing a bra increases a woman’s risk for breast cancer. The risk was similar, no matter how many hours per day women wore a bra, whether they wore a bra with an underwire, or at what age they first began wearing a bra.”
4. Your car
The claim: Do you remember the email that did the rounds claiming that dangerous levels of benzene, a cancer-causing chemical, are released from the plastic surfaces in your car? The advice was to open car windows to get rid of the benzene before turning the air conditioning on.
The truth: A German study reported that the air inside parked cars did not pose any health hazards. Although the analysis found some cancer-causing chemicals, these were also detected at similar levels in the air inside buildings.
Perhaps the only reason to open your windows before using your air con is to cool the car down more quickly. If it’s a really hot day, the temperature in a car can be more than 4°C higher than outside. So, when you open the windows, you’re replacing the hot air inside with cooler air from outside, making the air conditioning more effective when you switch it on.
If you’re still worried about benzene, however, stay away from cigarette smoke, which is a major source of benzene exposure.
5. Deodorant
The claim: Your underarm deodorant or antiperspirant that masks or prevents body odour is potentially harmful and could cause cancer. Cameron Diaz told Marc Malkin from E!News, “I don’t believe in antiperspirant. It’s really bad for you. I haven’t used it for almost 20 years.”
The truth: Good news is you don’t need to ditch the deo. The National Cancer institute says there is no truth in this myth. “Because underarm antiperspirants or deodorants are applied near the breast and contain potentially harmful ingredients, several scientists and others have suggested a possible connection between their use and breast cancer. However, no scientific evidence links the use of these products to the development of breast cancer,” the institute reports in a fact sheet.
According to breascancer.org, even the strongest antiperspirant won’t block all perspiration in your armpit. They say, “Most cancer-causing substances are removed by the kidneys and released through urine or processed by the liver. Sweating isn’t a significant way for your body to release toxins. And while there are concerns about chemicals, such as phthalates and parabens used for fragrance and preservation, from a whole list of personal care products (including antiperspirants) being absorbed by the body, these chemicals are unlikely to be culprits in causing breast cancer.”
So, what does cause cancer?
CANSA explains that cancer is a malignant growth or tumour, which is caused by abnormal and uncontrolled cell division.
Researchers believe that there are a number of factors that need to work together to cause cancer. These include genetic, environmental or constitutional characteristics of the individual, according to Stanford Health Care.
Cancer risk factors include:
- Lifestyle factors, such as smoking, unhealthy diets and working with toxic chemicals
- Family history and genetic disorders
- Exposure to certain viruses, such as Epstein-Barr virus and HIV
- Environmental exposure to pesticides, fertilisers and UV rays
Image credit: iStock
Women’s frozen eggs ‘should be stored for longer’
The 10-year limit for keeping a woman’s frozen eggs is arbitrary and does not reflect current technology, campaigners say.
New class of solar cells, using lead-free perovskite materials
Lead-based perovskites already gained much attention as promising materials for low-cost and high-efficiency solar cells. However, the intrinsic instability and the toxicity of lead (Pb) have raised serious concerns of the viability of Pb-based perovskites, hindering large-scale commercialization of solar cells and similar devices based on these materials. As an alternative solution, Pb-free perovskites were recently proposed to counter the toxicity of lead-based perovskites, yet it is of little use due to lower efficiencies.
A recent study, led by Professor Tae-Hyuk Kwon in the School of Natural Science at UNIST has taken a major step toward the development of a new generation of solar cells, using lead-free perovskites. With its promising electronic properties, the new perovskite material has been demonstrated to function as a charge regenerator with dye-sensitized solar cells, thus enhancing both the overall efficiency and stability. Published in the November 2018 issue of Advanced Materials, their findings will open new possibilities for the application of lead-free perovskites in solar cells.
Among the various alternatives to lead, the research team used the vacancy-ordered double perovskite (Cs2SnI6). Despite their promising outlook, the surface states of Cs2SnI6 and their function remain largely unclear. Thus, a comprehensive study is necessary to clarify these features of Cs2SnI6 for the future design of Cs2SnI6-based devices.
Through this work, the team examined the charge transfer mechanism of Cs2SnI6 with the aim of clarifying the function of its surface state. For this purpose, a 3-electrode system was developed to observe charge transfer through the surface state of Cs2SnI6. Cyclic voltammetry and Mott-Schottky analyses were also used to probe the surface state of Cs2SnI6, whose potential is related to its bandgap.
Their analysis demonstrated that the surface state of Cs2SnI6 is highly redox active and can be effectively charged/discharged in the presence of iodide redox mediators. Besides, the preparation of a charge regenerator system based on Cs2SnI6 confirmed that charge transfer occurred through the surface state of Cs2SnI6.
“In case of Cs2SnI6, charge transfer occurred through the surface state of Cs2SnI6,” says HyeonOh Shin in the Combined MS./Ph.D in Chemistry at UNIST. “This will aid in the design of future electronic and energy devices, using Pb-free perovskites.”
Based on this strategy, the research team engineered hybrid solar cells, using a Cs2SnI6-based charge regenerator for organic dye-sensitized solar cells (DSSCs). Such solar cells generate electric current in the process where the oxidized organic dye returns to its original state.
“Due to a high volume of electrical charges in organic dyes that show high connectivity with the surface state of Cs2SnI6, more electric current were generated,” says Byung-Man Kim in the Department of Chemistry at UNIST, another lead author of this study. “Consequently, Cs2SnI6 shows efficient charge transfer with a thermodynamically favorable charge acceptor level, achieving a 79% enhancement in the photocurrent density compared with that of a conventional liquid electrolyte.”
This study has attracted considerable attention among researchers, as it examined the charge transfer mechanism of Cs2SnI6 with the aim of clarifying the function of its surface state. Their results suggest that the surface state of Cs2SnI6 is the main charge transfer pathway in the presence of a redox mediator and should be considered in future designs of Cs2SnI6‐based devices.
