by Davide Castelvecchi

Long after most chemists had given up trying, a team of researchers has synthesized the first ring-shaped molecule of pure carbon — a circle of 18 atoms.

The chemists started with a triangular molecule of carbon and oxygen, which they manipulated with electric currents to create the carbon-18 ring. Initial studies of the properties of the molecule, called a cyclocarbon, suggest that it acts as a semiconductor, which could make similar straight carbon chains useful as molecular-scale electronic components.

It is an “absolutely stunning work” that opens up a new field of investigation, says Yoshito Tobe, a chemist at Osaka University in Japan. “Many scientists, including myself, have tried to capture cyclocarbons and determine their molecular structures, but in vain,” Tobe says. The results appear in Science1 on 15 August.

Pure carbon comes in several different forms, including diamond, graphite and ‘nanotubes’. Atoms of the element can form chemical bonds with themselves in various configurations: for example, each atom can bind to four neighbours in a pyramid-shaped pattern, as in diamond; or to three, as in the hexagonal patterns that make up the single-atom-thick sheets of graphene. (Such a three-bond pattern is also found in bulk graphite as well as in carbon nanotubes and in the globular molecules called fullerenes.)

But carbon can also form bonds with just two nearby atoms. Nobel-prizewinning chemist Roald Hoffmann at Cornell University in Ithaca, New York, and others have long theorized that this would lead to pure chains of carbon atoms. Each atom might form either a double bond on each side — meaning the adjacent atoms share two electrons — or a triple bond on one side and a single bond on the other. Various teams have attempted to synthesize rings or chains based on this pattern.

But because this type of structure is more chemically reactive than graphene or diamond, it is less stable, especially when bent, says chemist Przemyslaw Gawel of the University of Oxford, UK. Synthesizing stable chains and rings has usually required the inclusion of elements other than carbon. Some experiments have hinted at the creation of all-carbon rings in a gas cloud, but they have not able to find conclusive proof.

One ring
Gawel and his collaborators have now created and imaged the long-sought ring molecule carbon-18. Using standard ‘wet’ chemistry, his collaborator Lorel Scriven, an Oxford chemist, first synthesized molecules that included four-carbon squares coming off the ring with oxygen atoms attached to squares. The team then sent their samples to IBM laboratories in Zurich, Switzerland, where collaborators put the oxygen–carbon molecules on a layer of sodium chloride, inside a high-vacuum chamber. They manipulated the rings one at a time with electric currents (using an atomic-force microscope that can also act as a scanning-tunelling microscope), to remove the extraneous, oxygen-containing parts. After much trial-and-error, micrograph scans revealed the 18-carbon structure. “I never thought I would see this,” says Scriven.

The IBM researchers showed that the 18-carbon rings had alternating triple and single bonds. Theoretical results had disagreed over whether carbon-18 would have this kind of structure, or one made entirely of double bonds.

Alternating bond types are interesting because they are supposed to give carbon chains and rings the properties of semiconductors. The results suggest that long, straight carbon chains might be semiconductors, too, Gawel says, which could make them useful as components of future molecular-sized transistors.

For now, the researchers are going to study the basic properties of carbon-18, which they have been able to make one molecule at a time only. They are also going to keep trying alternative techniques that might yield greater quantities. “This is so far very fundamental research,” Gawel says.

“The work is beautiful,” says Hoffmann, although he adds that it remains to be seen whether carbon-18 is stable when lifted off the salt surface, and whether it can be synthesized more efficiently than one molecule at a time.

doi: 10.1038/d41586-019-02473-z
1. Kaiser, K. et al. Science (2019).


Scientists from Harvard University’s Dana-Farber Cancer Institute have found evidence that a chemical derived from cannabis may be capable of extending the life expectancy for those with pancreatic cancer.

Pancreatic cancer makes up just 3 percent of all cancers in America. But with a one-year survival rate of just 20 percent (and five-year survival rate of less than 8), it’s predicted to be the second leading cause of cancer-related death by 2020.

Headlines about the illness, as a result, tend to be discouraging. But this month scientists from Harvard University’s Dana-Farber Cancer Institute have released some much-needed good news. In their study, published in the journal Frontiers of Oncology on July 23, the researchers revealed that a chemical found in cannabis has demonstrated “significant therapy potential” in treatment of pancreatic cancer.

The specific drug, called FBL-03G, is a derivative of a cannabis “flavonoid” — the name for a naturally-occurring compound found in plants, vegetables and fruits which, among other purposes, provides their vibrant color. Flavonoids from cannabis were discovered by a London researcher named Marilyn Barrett in 1986, and were later found to have anti-inflammatory benefits.

But while scientists long suspected that cannabis flavonoids may have therapeutic potential, the fact that they make up just 0.14 percent of the plant meant that researchers would need entire fields of it to be grown in order to extract large enough quantities. That changed recently when scientists found a way to genetically engineer cannabis flavonoids — making it possible to investigate their benefits.

Enter the researchers at Dana-Farber, who decided to take the therapeutic potential of one of these flavonoids, FBL-03G, and test it on one of the deadliest cancers through a lab experiment. The results, according to Wilfred Ngwa, PhD, an assistant professor at Harvard and one of the study’s researcher, were “major.”

“The most significant conclusion is that tumor-targeted delivery of flavonoids, derived from cannabis, enabled both local and metastatic tumor cell kill, significantly increasing survival from pancreatic cancer,” Ngwa tells Yahoo Lifestyle. “This has major significance, given that pancreatic cancer is particularly refractory to current therapies.”

Ngwa says that the study is the first to demonstrate the potential new treatment for pancreatic cancer. But on top of successfully killing those cells, the scientist found FBL-03G capable of attacking other cancer cells — which was startling even to them. “We were quite surprised that the drug could inhibit the growth of cancer cells in other parts of the body, representing metastasis, that were not targeted by the treatment,” says Ngwa. “This suggests that the immune system is involved as well, and we are currently investigating this mechanism.”

The significance of that, says Ngwa, is that, because pancreatic cancer is often diagnosed in later stages, once it has spread, and the flavonoids seem to be capable of killing other cancer cells, it may mean the life expectancy of those with the condition could increase.

“If successfully translated clinically, this will have major impact in treatment of pancreatic cancer,” says Ngwa.

The next step for the Harvard researchers is to complete ongoing pre-clinical studies, which Ngwa hopes will be completed by the end of 2020. That could set the stage for testing the new treatment in humans, opening up a new window of hope for a group long in need of it.

by Quirin Schiermeier

Efforts to curb greenhouse-gas emissions and the impacts of global warming will fall significantly short without drastic changes in global land use, agriculture and human diets, leading researchers warn in a high-level report commissioned by the United Nations.

The special report on climate change and land by the Intergovernmental Panel on Climate Change (IPCC) describes plant-based diets as a major opportunity for mitigating and adapting to climate change ― and includes a policy recommendation to reduce meat consumption.

On 8 August, the IPCC released a summary of the report, which is designed to inform upcoming climate negotiations amid the worsening global climate crisis. More than 100 experts, around half of whom hail from developing countries, worked to compile the report in recent months.

“We don’t want to tell people what to eat,” says Hans-Otto Pörtner, an ecologist who co-chairs the IPCC’s working group on impacts, adaptation and vulnerability. “But it would indeed be beneficial, for both climate and human health, if people in many rich countries consumed less meat, and if politics would create appropriate incentives to that effect.”

Deforestation concerns
Researchers also note the relevance of the report to tropical rainforests, with concerns mounting about accelerating rates of deforestation. The Amazon rainforest is a huge carbon sink that acts to cool global temperature, but rates of deforestation are rising, in part because of the policies and actions of the government of Brazilian President Jair Bolsonaro.

Unless stopped, deforestation could turn much of the remaining Amazon forests into a degraded type of desert, and could release more than 50 billion tonnes of carbon into the atmosphere in 30 to 50 years, says Carlos Nobre, a climate scientist at the University of São Paolo in Brazil. “That’s very worrying,” he says.

“Unfortunately, some countries don’t seem to understand the dire need of stopping deforestation in the tropics,” says Pörtner. “We cannot force any government to interfere. But we hope that our report will sufficiently influence public opinion to that effect.”

Paris goals
Although the burning of fossil fuels for energy and transport garners the most attention, activities relating to land management, including agriculture and forestry, produce almost one-quarter of heat-trapping gases resulting from human activities. The race to limit global warming to 1.5°C above pre-industrial levels ― the goal of the international Paris climate agreement made in 2015 ― might be a lost cause unless land is used in a more sustainable and climate-friendly way, the latest IPCC report says.

The report highlights the need to preserve and restore forests, which soak up carbon from the air, and peatlands, which release carbon if dug up. Cattle raised on pastures created by clearing woodland are particularly emission-intensive. This practice often comes with large-scale deforestation, as seen in Brazil and Colombia. Cows also produce large amounts of methane, a potent greenhouse gas, as they digest their food.

The report states with high confidence that balanced diets featuring plant-based and sustainably produced animal-sourced food “present major opportunities for adaptation and mitigation while generating significant co-benefits in terms of human health”.

By 2050, dietary changes could free up several million square kilometres of land, and reduce global CO2 emissions by up to eight billion tonnes per year, relative to business as usual, the scientists estimate (see ‘What if people ate less meat?’).

“It’s really exciting that the IPCC is getting such a strong message across,” says Ruth Richardson in Toronto, Canada, the executive director at the Global Alliance for the Future of Food, a strategic coalition of philanthropic foundations. “We need a radical transformation, not incremental shifts, towards a global land-use and food system that serves our climate needs.”

Careful management
The report cautions that land must remain productive to feed a growing world population. Warming enhances plant growth in some regions, but in others ― including northern Eurasia, parts of North America, Central Asia and tropical Africa ― increasing water stress seems to reduce vegetation. So the use of biofuel crops and the creation of new forests ― seen as measures with the potential to mitigate global warming ― must be carefully managed to avoid the risk of food shortages and biodiversity loss, the report says.

Farmers and communities around the world must also grapple with more intense rainfall, floods and droughts resulting from climate change, warns the IPCC. Land degradation and expanding deserts threaten to affect food security, increase poverty and drive migration.

About one-quarter of Earth’s ice-free land area seems to be suffering from human-induced soil degradation already ― and climate change is expected to make thing worse, particularly in low-lying coastal areas, river deltas, drylands and permafrost areas. Sea-level rise is also adding to coastal erosion in some regions, the report says.

Industrialized farming practices are responsible for much of the observed soil erosion, and for soil pollution, says André Laperrière, the executive director of Global Open Data for Agriculture and Nutrition in Wallingford, UK, an initiative that aims to make relevant scientific information accessible worldwide.

The report might provide a much-needed, authoritative call to action, he says. “The biggest hurdle we face is to try and teach about half a billion farmers globally to re-work their agricultural model to be carbon sensitive.”

Nobre also hopes that the IPCC’s voice will give greater prominence to land-use issues in upcoming climate talks. “I think that the policy implications of the report will be positive in terms of pushing all tropical countries to aim at reducing deforestation rates,” he says.

Regular assessments
Since 1990, the IPCC has regularly assessed the scientific literature, producing comprehensive reports every six years or so, and special reports ― such as today’s ― on specific aspects of climate change, at irregular intervals.

A special report released last year concluded that global greenhouse-gas emissions, which hit an all-time high of more than 37 billion tonnes in 2018, must decline sharply in the very near future to limit global warming to within 1.5°C of pre-industrial levels ― and that this will require drastic action without further delay. The IPCC’s next special report, about the ocean and ice sheets in a changing climate, is due next month.

Governments from around the world will consider the IPCC’s latest findings at a UN climate summit next month in New York. The next round of climate talks of parties to the Paris agreement will then take place in December in Santiago.

António Guterres, the UN secretary-general, said last week that it is “absolutely essential” to implement that landmark agreement ― and “to do so with an enhanced ambition”.

“We need to mainstream climate-change risks across all decisions,” he said. “That is why I am telling leaders don’t come to the summit with beautiful speeches.”

Nature 572, 291-292 (2019)

doi: 10.1038/d41586-019-02409-7

Brain tissue from deceased patients with Alzheimer’s has more tau protein buildup (brown spots) and fewer neurons (red spots) as compared to healthy brain tissue.

By Yasemin Saplakoglu

Alzheimer’s disease might be attacking the brain cells responsible for keeping people awake, resulting in daytime napping, according to a new study.

Excessive daytime napping might thus be considered an early symptom of Alzheimer’s disease, according to a statement from the University of California, San Francisco (UCSF).

Some previous studies suggested that such sleepiness in patients with Alzheimer’s results directly from poor nighttime sleep due to the disease, while others have suggested that sleep problems might cause the disease to progress. The new study suggests a more direct biological pathway between Alzheimer’s disease and daytime sleepiness.

In the current study, researchers studied the brains of 13 people who’d had Alzheimer’s and died, as well as the brains from seven people who had not had the disease. The researchers specifically examined three parts of the brain that are involved in keeping us awake: the locus coeruleus, the lateral hypothalamic area and the tuberomammillary nucleus. These three parts of the brain work together in a network to keep us awake during the day.

The researchers compared the number of neurons, or brain cells, in these regions in the healthy and diseased brains. They also measured the level of a telltale sign of Alzheimer’s: tau proteins. These proteins build up in the brains of patients with Alzheimer’s and are thought to slowly destroy brain cells and the connections between them.

The brains from patients who had Alzheimer’s in this study had significant levels of tau tangles in these three brain regions, compared to the brains from people without the disease. What’s more, in these three brain regions, people with Alzheimer’s had lost up to 75% of their neurons.

“It’s remarkable because it’s not just a single brain nucleus that’s degenerating, but the whole wakefulness-promoting network,” lead author Jun Oh, a research associate at UCSF, said in the statement. “This means that the brain has no way to compensate, because all of these functionally related cell types are being destroyed at the same time.”

The researchers also compared the brains from people with Alzheimer’s with tissue samples from seven people who had two other forms of dementia caused by the accumulation of tau: progressive supranuclear palsy and corticobasal disease. Results showed that despite the buildup of tau, these brains did not show damage to the neurons that promote wakefulness.

“It seems that the wakefulness-promoting network is particularly vulnerable in Alzheimer’s disease,” Oh said in the statement. “Understanding why this is the case is something we need to follow up in future research.”

Though amyloid proteins, and the plaques that they form, have been the major target in several clinical trials of potential Alzheimer’s treatments, increasing evidence suggests that tau proteins play a more direct role in promoting symptoms of the disease, according to the statement.

The new findings suggest that “we need to be much more focused on understanding the early stages of tau accumulation in these brain areas in our ongoing search for Alzheimer’s treatments,” senior author Dr. Lea Grinberg, an associate professor of neurology and pathology at the UCSF Memory and Aging Center, said in the statement.

The findings were published Monday (Aug. 12) in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.


We know that a range of factors influence weight, including those related to lifestyle and genetics, but researchers have now identified six specific exercises that seem to offer the best chance of keeping your weight down – even if your genes don’t want you to.

Based on an analysis of 18,424 Han Chinese adults in Taiwan, aged between 30 and 70 years old, the best ways of reducing body mass index (BMI) in individuals predisposed to obesity are: regular jogging, mountain climbing, walking, power walking, dancing (to an “international standard”), and lengthy yoga practices.

But interestingly, many popular exercise types weren’t shown to do much good for those who’s genetic risk score makes them more likely to be obese.

Specifically, exercises including cycling, stretching, swimming and legendary console game Dance Dance Revolution don’t appear to be able to counteract genetic bias (though are beneficial in many other ways).

“Our findings show that the genetic effects on obesity measures can be decreased to various extents by performing different kinds of exercise,” write the researchers in their paper published in PLOS Genetics.

“The benefits of regular physical exercise are more impactful in subjects who are more predisposed to obesity.”

Besides BMI, the team also looked at four other obesity measures for a more complete picture: body fat percentage (BFP), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR).

Regular jogging – 30 minutes, three times a week – turned out to be the most effective way of counteracting obesity genes across all of them.

The researchers also suggest, based on the information dug up in the Taiwan BioBank database, that the less effective forms of exercise typically don’t use up as much energy, which is why they don’t work quite so well.

The researchers specifically noted that activities in cold water, such as swimming, could make people hungrier and cause them to eat more.

The study was able to succeed in one of its main aims, which was to show that having a genetic disposition towards obesity doesn’t mean that obesity is inevitable – the right type of exercise, carried out regularly, can fight back against that built-in genetic coding.

“Obesity is caused by genetics, lifestyle factors, and the interplay between them,” epidemiologist Wan-Yu Lin, from the National Taiwan University, told Newsweek. “While hereditary materials are inborn, lifestyle factors can be determined by oneself.”

It’s worth noting that not every type of exercise was popular enough within the sample population to be included: activities like weight training, table tennis, badminton or basketball may or may not be helpful, too. There wasn’t enough data to assess.

But with obesity numbers rising sharply across the world – and 13 percent of the global population now thought to quality as being obese – it’s clear that measures need to be taken to reverse the trend.

Being obese affects our physiological health in the way it increases the risk of cardiovascular disease, some cancers, and other issues; and there’s evidence that being seriously overweight can have a negative effect on our brains too.

Studies like this latest one can point towards ways of sticking at a healthy weight, even when the genetic cards are stacked against it. In some cases all it takes is a few minutes of exertion per day.

“Previous studies have found that performing regular physical exercise could blunt the genetic effects on BMI,” conclude the researchers.

“However, few studies have investigated BFP or measures of central obesity. These obesity measures are even more relevant to health than BMI.”

The research has been published in PLOS Genetics.


When you want to lose weight, there are two things you do: eat less and exercise more.

Just cutting calories should cause you to drop pounds. But exercise alone is rarely enough for weight loss. Life isn’t fair, after all.

Think of it this way: When going on a 30-minute brisk walk at about 4 miles per hours (that’s a 15-minute mile), a 155-pound person burns about 167 calories, according to Harvard Medical School. Want to celebrate your accomplishment? That exercise is quickly erased by a large scoop of vanilla ice cream or two small chocolate chip cookies.

If more serious exercise is your thing, 30 minutes of vigorous stationary bicycling burns 391 calories. But that gets wiped away with one slice of pepperoni pizza.

It doesn’t seem fair how all that effort can be nullified by a few bites of tasty food.

Is more exercise the answer?

It seems like simple math: If exercising for x minutes burns y calories, then just exercise longer and burn more calories. But research shows it’s not that easy.

Recently, New Scientist explained it with a story called, “Why doing more exercise won’t help you burn more calories.” Science writer Teal Burrell explored the idea of the so-called exercise paradox. People who dramatically increase their workout regimens often find that despite all the sweat and motion, they shed few pounds. Scientists have several theories why that might happen.

They eat more. You went for a grueling hike and are so proud of yourself, so you reward yourself later with a chocolate shake. People tend to overestimate the calories they burn when they exercise. In one study, people worked out on a treadmill and then were told to eat from a buffet the amount of food that equaled the calories they thought they burned. They guessed they had burned about 800 calories and ate about 550, when they had really burned just 200.

They move less. You went on that grueling hike in the morning, so you sprawled on the couch the rest of the day. Another theory is that people make up for their workouts by spending the rest of the time being sedentary. These are called “compensatory behaviors” when the moving and not moving balance each other out. But exercise physiologist Lara Dugas of Loyola University doesn’t buy this idea. “That doesn’t mean you lose that 500-calorie run because you’re sedentary for the rest of the day,” she tells New Scientist. “That doesn’t make sense.”

The body adapts. The theory that seems to make the most sense is that when you exercise more, your body adjusts by spending less energy on internal functions, from the immune system to digestion. Those systems that are working in the background, spending calories, just become more efficient when you exercise more, researchers think.

The role of exercise

Mathematician and obesity researcher Kevin Hall explained to Vox why adding more exercise probably won’t lead to much weight loss. Hall used the National Institutes of Health’s Body Weight Planner to calculate that if a 200-pound man added 60 minutes of medium-intensity running four days per week for a month while keeping his calorie intake the same, he’d lose five pounds. “If this person decided to increase food intake or relax more to recover from the added exercise, then even less weight would be lost,” Hall added.

So if someone is trying to lose a lot of weight, it would take a lot of time and effort to try to lose pounds based on exercise alone.

But of course, that doesn’t mean you should cancel your gym membership and toss your sneakers into the back of your closet. Exercise is still a key part of the one-two punch to weight loss. You just have to combine it with calorie control.

Nutritionists will say that weight loss is about 80% diet and 20% exercise. So yes, watch the brownies and the snacks if you’re trying to lose the love handles, but keep moving. It’s an eat-move combination that does require smart eating and regular movement to be healthy.

Within four hours of a traumatic experience, certain physiological markers—namely, sweating—are higher in people who go on to develop posttraumatic stress disorder (PTSD), according to a new study by a researcher at Case Western Reserve University and other institutions.

Around 90% of people who experience a traumatic event do not develop PTSD, according to existing data and research, making the medical community eager for better insights into the 10% who do—and for how to best treat these patients.

The study, conducted at Atlanta’s Grady Memorial Hospital, found that micro perspirations—detected non-invasively by a mobile device in an emergency department—can be plugged into a new mathematical model developed by the researchers to help predict who may be more at risk for developing PTSD.

The findings are especially important for targeting early treatment efforts and prevention of the disorder, said Alex Rothbaum, a pre-doctoral researcher in the Department of Psychological Sciences in the College of Arts and Sciences at Case Western Reserve.

“With PTSD, there is a need for more reliable and immediate patient information, especially in situations where research suggests people may underreport their own symptoms, such as with men, and those who live in violent neighborhoods or are on active duty,” said Rothbaum, a co-author of the study, which was published in the journal Chronic Stress.

“While skin is always secreting sweat, our method can discern meaningful, actionable information from perspirations too small for the naked eye to see,” he added.

The measurement differs from traditional practices to diagnose PTSD, which look for psychological differences in patients based on self-reported data and clusters of symptoms defined by the Diagnostic and Statistical Manual of Mental Disorders (often referred to as the DSM) published by the American Psychiatric Association.

“Eventually, this finding may help contribute to changes in how we diagnose and treat PTSD, pointing us toward which patients would do better in therapy, with medication, or a combination of the two—or no treatment at all,” said Rothbaum.

New testing device: less expensive, more accessible
Researchers hope the PTSD test can become available and standard in emergency departments, aided by the recent development of a practical and inexpensive device that can plug into common tablets and can measure “skin conductance response”—a measure of sweating.

Before, such tests could only be conducted on a large stand-alone machine costing upwards of $10,000. While the new device lacks the sensitivity of its more expensive counterpart, the readings it provides can be used to determine who should continue with additional testing and who is not at risk for developing PTSD.

The study—which included nearly 100 patients—was prompted, in part, by recent research showing the ineffectiveness of current methods practiced with patients immediately after traumas, known as critical incident stress debriefing and psychological debriefing.

Both the new method and model created by researchers will need to be further validated by a larger study underway with a National Institutes of Health grant.

The research
The study was co-authored with researchers at Emory University School of Medicine: Rebecca Hinrichs, Sanne J. H. van Rooij, Jennifer Stevens, Jessica Maples-Keller and Barbara O. Rothbaum; Vasiliki Michopoulos of Emory and Yerkes National Primate Research Center; Katharina Schultebraucks and Isaac Galatzer-Levy of New York University School of Medicine; Sterling Winters of Wayne State University; Tanja Jovanovic of Emory and Wayne State; and Kerry J. Ressler of Emory and Harvard/ McLean Hospital.

The research was supported by the National Institute of Mental Health and a Brain and Behavior Research Foundation NARSAD Independent Investigator Award.

Sweating is a clue into who develops PTSD—and who doesn’t