It was previously thought ancient organisms called nectocaridids, which bear a resemblance to squid, were a type of cephalopod – marine molluscs with tentacles and a prominent head. But scientists, co-led by the University of Bristol, have now shown these creatures are actually an early descendent of arrow worms, also known as chaetognaths.

This surprising discovery means the rather simple marine arrow worms had ancestors with much more complex anatomies and a predatory role higher up in the food chain.

The study, in partnership with paleontologists at the Korean Polar Research Institute and University of Copenhagen, is the culmination of a series of excavation expeditions to Sirius Passet in North Greenland, which began nine years ago. The locality is famous for its extreme exceptional preservation of marine organisms from the Early Cambrian around 518 million years ago.

Co-lead author Dr Jakob Vinther, Associate Professor in Macroevolution at the University of Bristol, said: “Sirius Passet is a treasure trove of fossils from the Cambrian Explosion. We not only find delicate soft-bodied fossils but also their digestive systems, musculature and sometimes even their nervous system.

“Around 15 years ago a research paper, based on fossils from the famous Burgess Shale, claimed nectocaridids were cephalopods. It never really made sense to me, as the hypothesis would upend everything we otherwise know about cephalopods and their anatomy didn’t closely match cephalopods when you looked carefully.”

The research team’s excitement grew as fossils of the mysterious nectocaridids were unearthed in Sirius Passet for the first time.

By analysing 25 fossil specimens, the researchers were able to pinpoint where nectocaridids fit into the tree of life. The solution came from Sirius Passets’ unique preservation conditions resulting in their nervous systems commonly remaining intact.

“We discovered our nectocaridids preserve parts of their nervous system as paired mineralized structures, and that was a giveaway as to where these animals sit in the tree of life,” Dr Vinther explained.

Recently, the team uncovered fossils in Sirius Passet belonging to another branch of the animal tree – a small group of swimming worms called arrow worms or chaetognaths.

“These fossils all preserve a unique feature, distinct for arrow worms, called the ventral ganglion,” said co-lead author Dr Tae-Yoon Park of the Korean Polar Institute.

The ventral ganglion is a large mass of nerves situated on the belly of living arrow worms, which is unique to this type of creature. The unique anatomy of the organ combined with the special preservation conditions means it sometimes is replaced by phosphate minerals during decay.

Dr Park added: “We now had a smoking gun to resolve the nectocaridid controversy. Nectocaridids share a number of features with some of the other fossils that also belong to the arrow worm stem lineage. Many of these features are superficially squid-like and reflect simple adaptations to an active swimming mode of life in invertebrates, just like whales and ancient marine reptiles end up looking like fish when they evolve such a mode of life.”

The discovery helps reveal clues about arrow worms and their past.

“Nectocaridids have complex camera eyes just like ours. Living arrow worms can hardly form an image beyond working out roughly where the sun shines. So, the ancestors of arrow worms were really complex predators, just like the squids that only evolved about 400 million years later,” Dr Vinther added.

“We can therefore show how arrow worms used to occupy a role much higher in the food chain. Our fossils can be much bigger than a typical living arrow worm and combined with their swimming apparatus, eyes and long antennae, they must have been formidable and stealthy predators.”

As further evidence for nectocaridids being swimming carnivores, the researchers found several specimens with the carapaces of a swimming arthropod, called Isoxys, inside their digestive tract.

The fossil is named Nektognathus evasmithae. The species name honours Professor Eva Smith, the first female professor of law in Denmark and renowned human rights advocate.

Dr Vinther said: “My decision to name our fossil after Eva, is that this animal was a smart and stealthy fighter just like she is.”

Spintronics, short for “spin electronics,” is a field of technology that aims to go beyond the limits of conventional electronics. Traditional devices rely only on the electric charge of electrons to store and process information. Spintronics takes advantage of two additional quantum properties: spin angular momentum, which can be imagined as a built-in “up” or “down” orientation of the electron, and orbital angular momentum, which describes how electrons move around atomic nuclei. By using these extra degrees of freedom, spintronic devices can store more data in smaller spaces, operate faster, consume less energy, and retain information even when the power is switched off.

A longstanding challenge in spintronics has been the role of material defects. Introducing imperfections into a material can sometimes make it easier to “write” data into memory bits by reducing the current needed, but this typically comes at a cost: electrical resistance increases, spin Hall conductivity declines, and overall power consumption goes up. This trade-off has been a major obstacle to developing ultra-low-power spintronic devices.

Now, the Flexible Magnetic-Electronic Materials and Devices Group from the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences have found a way to turn this problem into an advantage. Their study, published in Nature Materials, focused on the orbital Hall effect in strontium ruthenate (SrRuO3), a transition metal oxide whose properties can be finely tuned. This quantum phenomenon causes electrons to move in a way determined by their orbital angular momentum.

Using custom-designed devices and precision measurement techniques, the researchers uncovered an unconventional scaling law that achieves a “two birds with one stone” outcome: Defect engineering simultaneously boosts both orbital Hall conductivity and orbital Hall angle, a stark contrast to conventional spin-based systems.

To explain this finding, the team linked it to the Dyakonov-Perel-like orbital relaxation mechanism. “Scattering processes that typically degrade performance actually extend the lifetime of orbital angular momentum, thereby enhancing orbital current,” said Dr. Xuan Zheng, a co-first author of the study.

“This work essentially rewrites the rulebook for designing these devices,” said Prof. Zhiming Wang, a corresponding author of the study. “Instead of fighting material imperfections, we can now exploit them.”

Experimental measurements confirm the technology’s potential: tailored conductivity modulation yielded a threefold improvement in switching energy efficiency.

This study not only provides new insights into orbital transport physics but also redefines design strategies for energy-efficient spintronics.

This study received support from the National Key Research and Development Program of China, the National Natural Science Foundation of China, and other funding bodies.

But current STEGs have major efficiency limitations preventing them from being more widely adopted as a practical form of energy production. Right now, most solar thermoelectric generators convert less than 1 percent of sunlight into electricity, compared to roughly 20 percent for residential solar panel systems.

That gap in efficiency was dramatically reduced through new techniques developed by researchers at the University of Rochester’s Institute of Optics. In a study published in Light: Science and Applications, the team described their unique spectral engineering and thermal management methods to create a STEG device that generates 15 times more power than previous devices.

“For decades, the research community has been focusing on improving the semiconductor materials used in STEGs and has made modest gains in overall efficiency,” says Chunlei Guo, a professor of optics and of physics and a senior scientist at Rochester’s Laboratory for Laser Energetics. “In this study, we don’t even touch the semiconductor materials — instead, we focused on the hot and the cold sides of the device instead. By combining better solar energy absorption and heat trapping at the hot side with better heat dissipation at the cold side, we made an astonishing improvement in efficiency.”

The new, high-efficiency STEGs were engineered with three strategies. First, on the hot side of the STEG, the researchers used a special black metal technology developed in Guo’s lab to transform regular tungsten to selectively absorb light at the solar wavelengths. Using powerful femtosecond laser pulses to etch metal surfaces with nanoscale structures, they enhanced the material’s energy absorption from sunlight, while also reducing heat dissipation at other wavelengths.

Second, the researchers “covered the black metal with a piece of plastic to make a mini greenhouse, just like on a farm,” says Guo. “You can minimize the convection and conduction to trap more heat, increasing the temperature on the hot side.”

Lastly, on the cold side of the STEG, they once again used femtosecond laser pulses, but this time on regular aluminum, to create a heat sink with tiny structures that improved the heat dissipation through both radiation and convection. That process doubles the cooling performance of a typical aluminum heat dissipator.

In the study, Guo and his research team provided a simple demonstration of how their STEGS can be used to power LEDs much more effectively than the current methods. Guo says the technology could also be used to power wireless sensors for the Internet of Things, fuel wearable devices, or serve as off-grid renewable energy systems in rural areas.

The National Science Foundation, FuzeHub, and the Goergen Institute for Data Science and Artificial Intelligence supported the research.

After wrapping up its investigation at the contact between clay and olivine-bearing rocks at “Westport,” Perseverance is journeying south once more. Previously, attempts were made to drive uphill to visit a new rock exposure called “Midtoya.” However, a combination of the steep slope and rubbly, rock-strewn soil made drive progress difficult, and after several attempts, the decision was made to return to smoother terrain. Thankfully, the effort wasn’t fruitless, as the rover was able to gather data on new spherule-rich rocks thought to have rolled downhill from “Midtoya,” including the witch hat or helmet-shaped rock “Horneflya,” which has attracted much online interest.

More recently, Perseverance explored a site called “Kerrlaguna” where the steep slopes give way to a field of megaripples: large windblown sand formations up to 1 meter (about 3 feet) tall. The science team chose to perform a mini-campaign to make a detailed study of these features. Why such interest? While often the rover’s attention is focused on studying processes in Mars’ distant past that are recorded in ancient rocks, we still have much to learn about the modern Martian environment.

Almost a decade ago, Perseverance’s forerunner Curiosity studied an active sand dune at “Namib Dune” on the floor of Gale crater, where it took a memorable selfie. However the smaller megaripples — and especially dusty, apparently no longer active ones like at “Kerrlaguna” — are also common across the surface of Mars. These older immobile features could teach us new insights about the role that wind and water play on the modern Martian surface.

After arriving near several of these inactive megaripples, Perseverance performed a series of measurements using its SuperCam, Mastcam-Z, and MEDA science instruments in order to characterize the surrounding environment, the size and chemistry of the sand grains, and any salty crusts that may have developed over time.

Besides furthering our understanding of the Martian environment, documenting these potential resources could help us prepare for the day when astronauts explore the Red Planet and need resources held within Martian soils to help them survive. It is hoped that this investigation at “Kerrlaguna” can provide a practice run for a more comprehensive campaign located at a more extensive field of larger bedforms at “Lac de Charmes,” further along the rover traverse.

Written by Melissa Rice, Professor of Planetary Science at Western Washington University

Yue Wu, a graduate student at Sichuan University, will present her team’s results at the ACS Fall 2025 Digital Meeting, a meeting of the American Chemical Society.

“Losing weight can help some people prevent long-term health issues like diabetes and heart disease,” says Wu. “Our microbeads work directly in the gut to block fat absorption in a noninvasive and gentle way.”

Weight gain is caused by genetic and lifestyle factors, including eating a high-fat diet. A high-fat diet is defined by the U.S. Department of Agriculture as one where 35% or more of a person’s daily calories come from fat, as opposed to protein or carbohydrates. Some pharmaceuticals, such as orlistat, inhibit certain gastric enzymes from breaking down dietary fats, leading to less fat being absorbed by the body. Orlistat is a U.S. Food and Drug Administration (FDA)-approved medication and is effective for weight loss. However, for some people it causes serious side effects, including liver and kidney damage.

So, Wu and her colleagues wanted to target the fat absorption process with their weight-loss intervention but do so without negative side effects. “We want to develop something that works with how people normally eat and live,” says Wu.

To get started, the team created tiny plant-based beads that spontaneously form through a series of chemical bonds between the green tea polyphenols and vitamin E. These structures can form chemical tethers to fat droplets and serve as the fat-binding core of the microbeads. The researchers then coated the spheres in a natural polymer derived from seaweed to protect them from the acidic environment of the stomach. Once ingested, the protective polymer coating expands in response to the acidic pH, and the green tea polyphenols and vitamin E compounds bind to and trap partially digested fats in the intestine.

The microbeads are nearly flavorless, and the researchers foresee them being easily integrated into people’s diets. For example, the microbeads could be made into small tapioca- or boba-sized balls and added to desserts and bubble teas.

The researchers assessed the microbeads as a weight-loss treatment in rats. They put the animals into three groups (eight rats per group), those which were fed a high-fat diet (60% fats) either with or without microbeads and those which were fed a normal diet (10% fats) for 30 days. Rats fed the high-fat diet and microbeads:

• Lost 17% of their total body weight, while rats in the other groups didn’t lose weight.
• Had reduced adipose tissue and less liver damage compared to rats fed the high-fat and normal diets without microbeads.
• Excreted more fat in their feces compared to rats not given microbeads. The extra fat in the rats’ feces had no apparent ill effects on the animals’ health.

Additionally, the eight rats on high-fat diets that consumed microbeads showed similar intestinal fat excretion, but without the gastrointestinal side effects the researchers observed with a fourth group of rats they treated with orlistat.

Wu and her team have started working with a biotechnology company to manufacture the plant-based beads. “All the ingredients are food grade and FDA-approved, and their production can be easily scaled up,” says Yunxiang He, Sichuan University associate professor and co-author on Wu’s presentation.

They’ve also initiated a human clinical trial in collaboration with the West China Hospital of Sichuan University. “This represents a major step toward clinical translation of our polyphenol-based microbeads, following our foundational results,” says Wu. “We have officially enrolled 26 participants in our investigator-initiated trial, and we anticipate that preliminary data may become available within the next year.”

Title Oral polyphenol-based microbeads with synergistic demulsification and fat locking for obesity treatment

Abstract Excessive fat intake is strongly linked to the growing prevalence of obesity and associated metabolic disorders. Orlistat is the only Food and Drug Administration-approved drug for limiting the absorption of fat; however, the unabsorbed fat in the colon can cause severe side effects. Here, we report a polyphenol-mediated fat-locking (PmFL) microbead made of green tea polyphenol, dietary fiber (alginate), and D-a-tocopherol that efficiently captures and excludes a broad spectrum of dietary fat derivatives in the gut. Mechanistically, PmFL microbeads actively capture emulsified fat droplets through gastrointestinal pH-responsive expansion and facilitate multiple molecular interaction-driven demulsification and fat locking. The high-fat dieted rats orally administered PmFL microbeads showed 17.02% weight loss, accompanied by reduced adipose tissue, alleviated liver damage, and lower blood fat levels. Notably, the rats exhibited direct excretion of fat-containing feces without side effects or blood glucose fluctuations. Our work provides a basis for novel dietary strategies to combat obesity.

The research was funded by National Key R&D Program of China; the National Excellent Young Scientists Fund; the National Natural Science Foundation of China; the Talents Program of Sichuan Province; the Double First-Class University Plan of Sichuan University; the State Key Laboratory of Polymer Materials Engineering; the Tianfu Emei Program of Sichuan Province; the Postdoctoral Special Funding of Sichuan Province; the Postdoctoral Funding of Sichuan University; the Ministry of Education Key Laboratory of Leather Chemistry and Engineering; and the National Engineering Research Center of Clean Technology in Leather Industry.

The research, led by McGill University scientist Masha Prager-Khoutorsky in collaboration with an interdisciplinary team at McGill and the Research Institute of the McGill University Health Centre, suggests the brain may be a missing link in certain forms of high blood pressure – or hypertension – traditionally attributed to the kidneys.

“This is new evidence that high blood pressure can originate in the brain, opening the door for developing treatments that act on the brain,” said Prager-Khoutorsky, associate professor in McGill’s Department of Physiology.

Hypertension affects two-thirds of people over 60 and contributes to 10 million deaths worldwide each year. Often symptomless, the condition increases the risk of heart disease, stroke and other serious health problems.

About one-third of patients don’t respond to standard medications, which primarily target the blood vessels and kidneys based on the long-standing view that hypertension begins there. The study, published in the journal Neuron, suggests the brain may also be a key driver of the condition, particularly in treatment-resistant cases.

How salt disrupts the brain

To mimic human eating patterns, rats were given water containing two per cent salt, comparable to a daily diet high in fast food and items like bacon, instant noodles and processed cheese.

The high-salt diet activated immune cells in a specific brain region, causing inflammation and a surge in the hormone vasopressin, which raises blood pressure. Researchers tracked these changes using cutting-edge brain imaging and lab techniques that only recently became available.

“The brain’s role in hypertension has largely been overlooked, in part because it’s harder to study,” Prager-Khoutorsky said. “But with new techniques, we’re able to see these changes in action.”

The researchers used rats instead of the more commonly studied mice because rats regulate salt and water more like humans. That makes the findings more likely to apply to people, noted Prager-Khoutorsky.

Next, the scientists plan to study whether similar processes are involved in other forms of hypertension.

“Microglia regulate neuronal activity via structural remodeling of astrocytes” by Ning Gu et al., was published in Neuron and supported by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada and the Azrieli Foundation.