A local post office owner in Liverpool says he has never seen anything like the surge in demand for solar eclipse glasses, describing the rush as “crazy” as customers race to secure a pair before the celestial event.
The specialist glasses, which are essential for safely viewing a solar eclipse without damaging the eyes, have become a hot commodity as public excitement builds. Unlike ordinary sunglasses, eclipse glasses use specially designed filters that block out nearly all visible light, as well as harmful ultraviolet and infrared radiation, allowing viewers to look directly at the sun during the event without risking permanent eye damage.
Retailers across the region are reportedly struggling to keep pace with orders, with stock disappearing almost as soon as it arrives. The shortage highlights both the growing public interest in astronomical events and the challenges small businesses face when demand spikes unexpectedly. Experts continue to stress that looking directly at the sun without proper protection, even during a partial eclipse, can cause serious and irreversible eye damage, making certified eclipse glasses a crucial purchase for anyone hoping to witness the phenomenon safely.
As the date of the eclipse approaches, shoppers are being urged to act quickly and to verify that any glasses they purchase meet recognized international safety standards, as counterfeit or substandard products have previously circulated during periods of high demand.
Skywatchers across Scotland are keeping their fingers crossed as forecasts suggest cloud cover could obscure much of the country’s view of the upcoming solar eclipse. The partial eclipse, a striking celestial event where the Moon passes between the Earth and Sun, has generated excitement among astronomy enthusiasts and casual observers alike, but weather conditions may dampen the spectacle for many.
Meteorologists note that cloud patterns can shift in the hours leading up to the eclipse, so there remains hope that breaks in the cloud cover could offer fleeting glimpses of the phenomenon in some areas. Regions with clearer skies stand the best chance of witnessing the Moon’s shadow creep across the Sun, while those under thick cloud may need to rely on live broadcasts or online streams to experience the event.
Solar eclipses offer a valuable opportunity for scientific observation and public engagement with astronomy, reminding us of the dynamic relationship between the Earth, Moon and Sun. Experts continue to remind viewers never to look directly at the Sun without proper eye protection, such as certified eclipse glasses, even when the Sun is partially obscured. Those hoping to catch the event are encouraged to check localized weather updates as the time approaches, since conditions can change quickly and vary significantly between regions of Scotland.
A significant pollution incident has devastated fish populations along a 5-kilometer stretch of the Kilkeel River in Northern Ireland’s Mourne Mountains area, with officials warning that multiple generations of fish have been effectively wiped out.
The Department of Environment confirmed the extent of the damage, describing a scene of substantial ecological harm along the waterway. Rivers like the Kilkeel serve as vital habitats for fish species, and the destruction of multiple generations suggests both breeding adults and juvenile fish have perished, a setback that could take years to reverse.
Pollution incidents of this scale typically stem from agricultural runoff, chemical spills, or wastewater discharge, though the specific cause has not been detailed. Such events often deplete oxygen levels in the water or introduce toxins directly harmful to aquatic life, leaving rivers unable to support fish populations until natural recovery processes—or active restocking efforts—take hold.
Environmental officials are expected to continue investigating the source of the contamination as part of efforts to prevent future incidents and support the river’s long-term recovery. The Mourne Mountains area is prized for its natural beauty and biodiversity, making this loss particularly concerning for local conservationists and anglers who rely on healthy river ecosystems.
A hydrogen combustion vehicle has roared into the record books, hitting a top speed of 406 miles per hour and smashing the previous benchmark set back in 2004. The new mark is more than double the speed of that earlier record, marking a major leap forward for hydrogen-based propulsion technology in high-performance applications.
The achievement highlights growing momentum behind hydrogen as a viable alternative to fossil fuels, not just for everyday transportation but for extreme engineering feats as well. Unlike battery-electric vehicles, hydrogen combustion cars burn hydrogen fuel directly, producing power through a modified combustion process while emitting primarily water vapor rather than carbon dioxide. This makes the technology an intriguing middle ground between traditional internal combustion engines and zero-emission electric drivetrains.
Land speed record attempts have long served as proving grounds for emerging automotive technology, and this run is no exception. Engineers and clean energy advocates see the milestone as evidence that hydrogen power can compete on performance, not just sustainability credentials. As governments and manufacturers continue investing in hydrogen infrastructure, from fueling stations to industrial applications, records like this help build public confidence that clean energy vehicles don’t have to sacrifice speed or excitement.
While hydrogen combustion vehicles remain a niche category compared to battery-electric cars, breakthroughs like this one could help accelerate research and investment into hydrogen as a broader climate solution, particularly for sectors like aviation, shipping, and heavy trucking, where battery weight remains a significant hurdle.
In October 1982, engineers in Paraguay and Brazil closed the gates along the Paraná River, setting in motion the slow flooding of a valley that would soon disappear beneath the reservoir of what became the world’s largest dam by energy output. As the waters rose, they swallowed forests, riverbanks, and islands that had teemed with life for generations, forcing one of the most urgent wildlife rescue efforts in South American history.
Conservationists and volunteers scrambled against the clock, wading into rising floodwaters to capture and relocate thousands of stranded animals—from sloths and monkeys to snakes, birds, and small mammals—before their habitat vanished entirely. The operation, born of necessity rather than long-term planning, revealed both the resilience of wildlife rescue teams and the harsh trade-offs that come with large-scale hydroelectric development.
The flooding of the Itaipu reservoir ultimately submerged hundreds of square miles of subtropical forest, reshaping the region’s ecology and displacing countless species along with local communities. While the dam has since become a cornerstone of clean energy production for both nations, supplying a significant share of their electricity, its creation stands as a stark reminder of the ecological costs embedded in even the most celebrated renewable energy projects.
Decades later, the story of the 1982 rescue continues to inform conversations about how nations balance the promise of hydropower with the irreversible loss of biodiversity, raising questions that remain urgent as new dam projects are proposed across the globe.
Crowds gathered across Kent, Surrey and Sussex to witness a striking celestial event as the moon partially obscured the sun in a rare partial solar eclipse. Armed with specialised viewing glasses, telescopes fitted with solar filters, and pinhole projectors, spectators young and old turned their eyes skyward to catch a glimpse of the phenomenon.
The eclipse offered a dramatic reminder of the intricate mechanics governing our solar system, as the moon’s shadow crept across the sun’s face, temporarily dimming daylight and casting an eerie glow over the countryside. Astronomy enthusiasts and casual observers alike described the experience as awe-inspiring, with many capturing photographs to mark the occasion.
Local astronomy clubs and community groups had organised viewing events in parks, schools and public spaces, providing safe equipment and guidance to ensure onlookers could enjoy the spectacle without risking eye damage from direct sunlight exposure. Experts had urged the public in the days leading up to the event to avoid looking directly at the sun without proper protection.
Partial solar eclipses, while less dramatic than total eclipses, still offer a valuable opportunity for both amateur and professional astronomers to study solar activity and inspire public interest in space science. Such events also serve as a reminder of the delicate cosmic alignments that shape our understanding of the natural world, encouraging renewed curiosity about the skies above.
Skywatchers across Yorkshire turned their eyes upward as crowds gathered in York, Leeds, and Bradford to witness the most significant solar eclipse visible from the region since 1999. The rare celestial event drew families, students, and astronomy enthusiasts alike to public squares and open spaces, many armed with specialized eclipse glasses and homemade viewing devices to safely observe the spectacle.
Onlookers described the experience as “incredible,” with many noting the eerie dimming of daylight as the moon passed between the Earth and the sun. In York, crowds packed public viewing areas, while similar scenes unfolded in Leeds and Bradford, where local astronomy groups and science centers set up telescopes and provided guidance on safe viewing practices.
The eclipse offered a rare opportunity for the public to engage directly with a dramatic astronomical phenomenon, sparking widespread interest in solar science and inspiring curiosity about future celestial events. Local schools and community organizations used the occasion to educate the public about the mechanics of eclipses and the importance of protecting eyesight when observing the sun.
Events like this eclipse serve as reminders of the dynamic relationship between Earth and the wider solar system, offering moments of collective wonder that transcend everyday life. As skies cleared over Yorkshire, the shared experience underscored how such natural phenomena continue to captivate public imagination, uniting communities in a shared moment of awe beneath the same sky.
For the first time in my life, I have a proper garden, and I was determined to make the most of it. Back in spring, I went all in: seeds, trays, pots, grow bags, soil, and a shiny new watering can. My vision was modest but hopeful: a small patch of fruit and vegetables, flowers to attract pollinators, and a chance to teach my eldest child how things grow, and how to handle it when they don’t.
We started with tomatoes, a household favorite. The seedlings sprouted with promise, only to shrivel and die in the season’s first heatwave. It felt like a bad sign. The dahlias, ranunculus, and freesias I’d planted refused to bloom at all. Slowly, my gardening enthusiasm began to fade.
What started as a cozy parent-child project in patience and resilience is beginning to feel like something else entirely: a small, personal front line in the climate crisis. As heatwaves become more frequent and intense across Britain, pushing more regions into drought, the simple act of growing your own food is no longer just a hobby. It’s a test of adaptability, and increasingly, a luxury that requires more water, more vigilance, and more heartbreak than it once did.
My family’s failed harvest is a tiny story, but it echoes a much bigger one, as gardeners, allotment holders, and small-scale growers across the country grapple with unpredictable weather patterns that are reshaping how, and whether, we can grow our own food at all.
A stunning drone video capturing dozens of stingrays swimming together off the coast of New York has drawn widespread attention from beachgoers and marine life enthusiasts alike. The footage offers an unusual bird’s-eye perspective on cownose rays, a species known for its seasonal visits to Long Island’s waters.
Captured last Friday off Southampton, the video was filmed by Joanna Steidle, a Hamptons-based drone pilot recognized for her striking aerial ocean photography. The clip shows a large group of cownose rays gliding gracefully just beneath the water’s surface, their distinctive wing-shaped bodies visible in remarkable detail.
Cownose rays, which can grow wing spans of up to three feet, are known for traveling in large schools and typically arrive in the region during the warmer summer months. Despite their somewhat intimidating appearance, marine scientists describe the species as shy and generally harmless to humans, posing little threat to swimmers or beachgoers who might encounter them.
While the sight of so many rays moving together may seem unusual to casual observers, experts note that this behavior is a normal part of their seasonal pattern and that these creatures have likely been visiting Long Island’s coastal waters for decades. The viral footage has offered a rare glimpse into a natural phenomenon that typically goes unnoticed by those on shore, highlighting the rich marine biodiversity present just off New York’s beaches during summer.
At sunrise, the yacht Boaventura II departs Rio de Janeiro carrying a boatload of eager whale watchers. Just past the Cagarras Islands, a rocky archipelago three miles from Ipanema beach, passengers crowd the bow, eyes fixed on the horizon.
Their patience is quickly rewarded. A pod of bottlenose dolphins surfaces first, leaping and diving playfully near the boat. Moments later, two plumes of mist rise into the air—the telltale sign of humpback whales. The massive creatures breathe rhythmically at the surface before diving, their distinctive tail flukes briefly visible above the waves.
This scene, once unimaginable, has become increasingly common off Rio’s coast. Humpback whales, hunted to near extinction during the 20th century whaling era, have made a remarkable comeback in Brazilian waters. Their resurgence has sparked a booming whale-watching tourism industry, drawing visitors eager to witness these ocean giants up close.
Yet the very success story that brings tourists to the water is now raising concerns among marine biologists. As boat traffic increases to meet demand, researchers are questioning whether unchecked tourism growth could threaten the fragile recovery of the species. The challenge now facing Rio: how to celebrate and share this conservation triumph without loving the whales back toward danger.
At the quantum scale, tiny particles behave in bizarre ways. One reason for this is the uncertainty principle, which says that the more you know about where a quantum particle is, the less you can know about how fast it’s moving, and vice versa. Recently, this rule got a rare upgrade. The new uncertainty principle relates to fractals, shapes that remain equally complex no matter how much you…
For several months, I had been on the hunt for new T-shirts. I vaguely had a vision of what they should look like: not so different from my current T-shirts, except in some way elevated and, more urgent, free of stains or holes. Perhaps they could come in interesting colors? Ideally, they would not be made in sweatshops. There were many, many shirts that seemed to meet these criteria—and with a few clicks, they could be delivered to my doorstep, maybe even by tomorrow. And still, I had purchased none of them.
The problem is the overabundance of options. The problem is too much information, or too little information. The problem is inflation, which has eroded any sense I had of what a T-shirt is supposed to cost. Yet none of them alone can explain why shopping is sucking up more of my time—and maybe yours too. “I don’t think people are actually enjoying the shopping process,” Jaehee Jung, a University of Delaware professor who studies the psychology of fashion, told me. “People spend more time contemplating, and the pre-decision process seems to be taking longer.”
Everywhere, someone is selling something: on Instagram and TikTok, over email and via text. At this point, the boundary between “shopping” and “not shopping” has all but collapsed. There is now a third state: “a little bit shopping.” Shopping is visiting a store or website on purpose, examining the wares, and either buying or not buying them. A little bit shopping is the constant thrum of consumer opportunities that lead mostly to more consumer opportunities. It is looking at a pair of shoes, which leads to looking at another pair of shoes, and another, and then you’re $15 short of the minimum for free shipping and is there anything else you need? It is the feeling of being haunted by the targeted ads that populate your social-media feeds. Even if you never click on them, their very presence contributes to the overwhelming sense that the retail landscape is infinite—so infinite that perfection must exist, and if you look long enough and hard enough, somewhere in the universe, it is probably on sale.
In small doses, a little bit shopping can be fun, a private thrill. It is both a genuine attempt at making a purchase, and a hobby that is infinitely expandable to fill any length of time. Who among us has not scrolled through sweater sales while trapped on a work call? It does not require spending money, nor does it apply to urgent and essential purchases: You don’t a little bit shop for baby Tylenol. “No matter what you’re doing on the computer,” Wendy Woloson, a material historian at Rutgers University at Camden, told me, “it seems like there’s a really easy drift into the shopping mode.”
Unlike brick-and-mortar stores, the internet never closes. You can a little bit shop forever, until you are also a little bit miserable. Shopping in person, then, ought to solve the problem, but it often doesn’t. A survey of 30 retailers by the consulting firm AlixPartners found that, on average, they carried only 9 percent of their online offerings in store. The shoes are out of stock in your size, but have you checked the website? You could stand in line to buy lesser, uglier shoes and be done with it, but why? Online, beautiful shoes are infinite and, in theory, instant.
The more mindful you are about various concerns—overconsumption, worker exploitation, microplastics—the higher the bar climbs: I need not only black pants, but ethical black pants that I can wear to the beach, but also to the opera, and that will be flattering from now until my death. No such pants exist, which is why I don’t have any, but as long as you’re a little bit shopping, the possibility exists.
This state of perpetual shopping has been building for ages. People were a little bit shopping on Amazon and eBay in 2005. But the feeling has become even more acute in recent years as e-commerce has taken over and affiliate marketing has boomed. In addition to sites such as Wirecutter and The Strategist, and every media property with a gift guide, all kinds of influencers have opinions about what you should buy (and may receive a commission if you do).
My own digital social life is a mix of people I know, people I don’t know, brands that post like people, and people launching brands. Here is my high-school lab partner’s baby.Here is a plate of pasta. Here is a picture of an antique lamp for sale from an estate-sale company in Texas. “Everyone is trying to either make money or gain recognition”—and thereby make money—“for their taste,” Isabel Slone, who writes about fashion on the Substack Freak Palace, told me. An influencer can help move $1 million worth of swimsuits in three hours. For a solitary activity, a little bit shopping is perversely social. It is pleasantly intimate, knowing how an opinionated stranger feels about their chef’s knife, or their microwave, or the life-changing sweater that got them through their divorce and is available right now if you click the link in the bio. Whether it is helpful consumer education is a separate question: “I do think that the affiliate-link economy,” Slone said, “contributes to this constant feeling of not knowing exactly what is good.”
There is, of course, a way out. You could stop caring. You could embrace the good-enough and the suboptimal, understanding that a little bit shopping is a trap that keeps you shopping all the time. Eventually, I bought a T-shirt, which is in all ways absolutely adequate, and in no sense exceptional. And then, the next day, I saw a post about a T-shirt, which was better. I clicked.
The former Bibb County deputies were arrested this week amid a growing national debate over Flock cameras, which can be found on roads in every state but Alaska.
Andy Green, a 64-year-old retired Royal Air Force pilot from Britain, was already the only person to break the sound barrier on land. “The ground comes at you very, very quickly,” he said.
The event horizons of black holes that are far from equilibrium can now be described by the first and second laws of thermodynamics thanks to new work by theoretical physicists at Pennsylvania State University in the US. The result augments the work of the late Stephen Hawking and others who showed in the 1970s that these classical concepts have applications in idealized, static black holes.
Black holes are objects so dense that their gravitational pull prevents anything – even light – from escaping them. The “point of no return” of any object falling into a black hole is called the event horizon, and it represents the black hole’s mathematically defined “edge”.
Although black holes can be described using concepts from quantum mechanics and Einstein’s general theory of relativity, some 50 years ago physicists like Hawking and Jacob Bekenstein showed that the equations governing them are also astonishingly similar to the fundamental laws of thermodynamics. “This seminal observation sparked a rethinking of black holes in thermodynamics terms,” explains Abhay Ashtekar, a physicist at Penn State’s Eberly College who led the new study. In particular, Ashtekar says it meant that black holes could be assigned an entropy that is equal to the area of their event horizon.
The problem, he continues, is that technically, these relationships are only valid for black holes in equilibrium – that is, those that are stable and do not change over time. In contrast, real astrophysical black holes are constantly changing: they form, merge and eventually evaporate because of quantum effects.
“In these dynamical objects, event horizons are ‘teleological’, meaning that we need to know how a black hole will behave for all of eternity to be able to define its entropy today,” Ashtekar explains. “This notion of black hole entropy is therefore physically untenable. Indeed, this limitation was already recognized in the 1990s and it has been the elephant in the room since then.”
Extending the laws of thermodynamics
In their new work, Ashtekar and colleagues sought to overcome this limitation by replacing static event horizons with an alternative concept known as dynamical horizon segments. These segments are characterized by the physical properties of a black hole at a given moment in time, and other researchers have employed them in numerical simulations of black hole mergers and gravitational collapse. Indeed, Ashtekar and various colleagues had previously shown that dynamical horizons were a physically admissible replacement for event horizons.
However, Ashtekar says that these earlier studies had not addressed two central questions. These involved defining intensive parameters – analogues of pressure and temperature in ordinary thermodynamics systems such as gases – and defining the energy of a black hole by itself in a highly curved region of space-time at a given instant.
“Our study now shows that Einstein’s equations imply that these dynamical horizons also satisfy equations very similar to the first and second laws of thermodynamics,” Ashtekar tells Physics World. “What is more, the change in thermodynamical quantities of these horizons at any given moment in time are caused directly by fluxes of energy and changes in the angular momentum of the black hole at that instant.”
The researchers’ new calculations show that even when black holes are very far from equilibrium, their evolution defines specific trajectories in the space of different equilibrium states. “This allows us to transport observables from these states to instantaneous non-equilibrium ones,” explains Ashtekar. “Such a procedure cannot be applied to conventional thermodynamics systems; black holes are very special in this regard.”
Event horizons “entirely absent” when quantum effects are included
According to team member Daniel Paraizo, the new work treats the event horizon as a dynamical horizon segment that forms in a gravitational collapse and then evaporates because of quantum effects. Intriguingly, Paraizo says that within this framework, event horizons vanish entirely when quantum effects are included – a fact which, he says, “removes a great deal of confusion currently surrounding the issue of information loss from a black hole, for example”. This same finding, he notes, also supports an idea that Hawking advocated shortly before his death in 2018: the possibility that a “true” event horizon never actually forms.
The Penn State researchers now plan to build on their present work with theories involving both classical and quantum gravity. Team member Jonathan Shu says that such theories may provide a thermodynamic explanation of several puzzling features that have been observed in numerical simulations of black hole mergers. “We have also already extended our results to theories of gravity beyond general relativity,” he reveals. “For quantum gravity, dynamical horizon segments have been successfully deployed in the so-called semi-classical phase of black hole evaporation and work is underway to address still unanswered questions about the final stages of the process using a theory known as loop quantum gravity.”
The researchers report their work in Physical Review Letters. Ashtekar will also be speaking on this subject at Penrose Fest@95, which is due to be held in Oxford, UK in September.
A system will generally move towards equilibrium when a change is made to it in a process called relaxation. To predict the state of the system after some period of time, we only need to know its current state and the external conditions. However, some polymers have memory behaviours where the evolution of the system is not only dependent on the current state, but also on previous states. This is known as the Kovacs effect.
In this work, the researchers investigated the Kovacs effect in a system consisting of suspensions of rod-like nanoparticles. By applying an electric field to these nanoparticles they align, therefore the particles change the liquid’s optical anisotropy, which can be measured as birefringence, which is how the liquid changes light polarization. More birefringence means the particles are more aligned. Importantly, there are faster- and slower-relaxing nanoparticles because of their polydispersity and different sizes, meaning they align at different rates. By changing the strength of the electric field, the faster and slower nanoparticles become out of sync with each other. The future behaviour will then depend on the system’s previous history that is overall hidden by the global birefringence measurement; this is the Kovacs effect.
The researchers modelled the orientational dynamics using the Smoluchowski equation, which describes rotational diffusion of particles. They found that relaxation is not determined by a single timescale or relaxation mode. When some of the modes are fast and some are slow, memory effects will occur. The Kovacs effect is important because it shows that a simple strategy of applying a strong electric field before switching to the target field does not necessarily speed up relaxation. Due to memory effects arising from particles relaxing at different rates, the system overshoots the target state, reducing the expected gain in speed.
To overcome this, the researchers designed improved two- and three-step protocols that suppress the slowest relaxation modes rather than simply matching the average birefringence. These protocols reduce the memory effect, produce a smoother approach to equilibrium, and achieve faster relaxation, although the benefit of additional switching steps becomes progressively smaller. This research improves our understanding of memory effects in complex systems and provides a practical strategy for controlling nanoparticle dynamics more quickly and efficiently.
Topological materials have been receiving a lot of attention in recent years because of their potential applications in future electronic and quantum technologies.
These are a type of material whose electrons have properties that stay stable even when the material has small defects, impurities, or imperfections. They often have surface or edge behaviour that is very different from the interior, because of the structure of the material’s quantum states.
Researchers use quantities such as Berry curvature and Chern numbers to describe topological materials. Berry curvature measures how an electron’s quantum state changes as its momentum changes. Adding this curvature across the whole band gives a Chern number, a whole-number label that can show whether the material is topological.
A key question in this area is: when a material has topological properties, how much of that behaviour is actually tied to quantum entanglement?
In a new paper published recently, Kazuki Ikeda and Steven Rayan tackled this question using the spinless Haldane model. This is a widely used theoretical model for understanding topological materials. This model describes electrons moving on a honeycomb lattice, which has two different sublattices, called A and B.
Here, the researchers added an extra layer of analysis. Instead of only calculating whether the model is topological, they were able to determine where the topological signal comes from.
By introducing a filter based on quantum entanglement, they tested whether the Berry curvature is associated with electron states that are spread across both A and B sublattices, or with states that mostly sit on one sublattice.
They also focused on what happens when the system moves between different topological phases, giving a more organised way to describe what changes when the energy gap closes and the material switches phase.
These results will provide invaluable insights into understanding and designing topological materials going forward.
What’s also interesting here is that, in order to obtain these results, the authors employed Langlands-inspired mathematics to keep track of what changes when the material switches between topological phases.
The Langlands programme is an ambitious mathematical dictionary that tries to translate problems about numbers into problems about symmetry, geometry and analysis.
Although the link in this work is purely conceptual, it does show that Langlands-style structures can organise real physics problems in topological matter.
Tissue engineering offers a means to restore, maintain or replace biological tissues. But it is difficult to grow blood vessels using conventional fabrication techniques like 3D printing, as they are typically not precise enough to print fine capillaries and veins. A team of engineers from the Massachusetts Institute of Technology (MIT) has now developed a new approach to do just that, by using mechanical forces. Their blood-vessel-on-a-chip could be the first step in the scalable production of vascular networks that could then be implanted in the body to replace tissue that has been damaged by disease or injury.
The researchers, led by Ritu Raman, made their chip by filling a Petri dish with a gel containing nutrients and cell-growth factors. They then embedded a small magnet into the gel. Finally, they introduced a thin, hollow tube into the gel and coated the inside of the tube with live endothelial cells – the cells that naturally line blood vessels in the body.
Once anchored onto the inner walls of the tube, the endothelial cells began sprouting new, capillary-like vessels in the gel. And when the researchers moved the embedded magnet back and forth in different directions and by varying degrees, they found that the mechanical forces created by the moving magnet could stretch the vessels and increase the number of new capillaries that grew, as well as their length.
‘Steering’ blood vessel growth
“We also showed that blood vessel growth, or angiogenesis, could be directionally patterned using the mechanical forces created by the magnet and that these directions could change dynamically over time,” explains Raman. “This allows us to ‘steer’ blood vessel growth in all three spatial directions (x, y, z) and make complex geometries (like L-shaped branches) that would not be possible to fabricate using conventional methods.”
The researchers had previously demonstrated that biological cells are highly responsive to mechanical forces in the body, but they did not know how different types of forces – for example, stretching in different directions and at different degrees and frequencies – impacted the 3D structure of blood vessels. The main obstacle lay in developing a coupled magnet system to precisely stretch blood vessels in different directions. To achieve this, they designed a method for mechanically stimulating tissues, dubbed “magnetic matrix actuation”.
In their new work, which is detailed in PNAS, they went a step further and developed a method to accurately yet non-invasively stretch 3D blood vessel tissues they had built in the laboratory.
To better understand the effect of mechanical forces on angiogenesis, the MIT team decided to look into the role of a gene known as PIEZO1, which is just one of the many mechanically sensitive genes in the body. They built on the work of molecular biologist Ardem Patapoutian, who received the 2021 Nobel Prize in Physiology or Medicine for discovering that ion channels in cells open and close in response to mechanical pressure. One such ion channel is PIEZO1, which is regulated by the PIEZO1 gene.
By suppressing this PIEZO1 gene in the endothelial cells they studied, the researchers indeed observed that significantly fewer new blood vessels grew in the gel. This, they say, provides evidence that the applied mechanical forces in their experiment may have been opening the PIEZO1 ion channel in the endothelial cells, so triggering the new blood vessel growth.
“My group has always been interested in engineering artificial tissues that can be implanted in the body to repair damage caused by disease or traumatic injury, but such artificial tissues require integrated networks of blood vessels in order to function,” says Raman. “We hope that our method for precisely fabricating complex networks of blood vessels within engineered tissues will enable the development of such implants,” she tells Physics World.
The new label, which will begin to be applied next month, is an effort by the streaming service to be more transparent about A.I.-generated music on its app.
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