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Comment by Dr. Krishna Kumari Challa on February 28, 2025 at 10:43am

A brain that turned to glass: scientific explanation

A young man was lying in his bed when a viciously hot cloud of ash swept down from the erupting Mount Vesuvius and turned his brain to glass almost 2,000 years ago.

That is the theory Italian scientists proposed this week  to explain the strange case of the ancient Roman's brain, which they said is the only human tissue ever known to have naturally turned to glass.

This unique brain could rewrite the story of one of history's most famous natural disasters—and help protect people against this little-understood phenomenon during future volcanic eruptions, the scientists suggested.

When Mount Vesuvius—near the modern-day Italian city of Naples—erupted in 79 AD, the cities of Pompeii and Herculaneum were buried in a fast-moving blanket of rock and ash called a pyroclastic flow.

Thousands of bodies have been discovered at the sites effectively frozen in time, offering a glimpse into the daily life of ancient Rome.

In the 1960s, the charred remains of a man aged roughly 20 were found on a wooden bed in a Herculaneum building dedicated to worshiping the Roman Emperor Augustus.

Italian anthropologist Pier Paolo Petrone, a co-author of a new study, noticed something strange in 2018.

He saw that something was shimmery in the shattered skull! What was left of the man's brain had been transformed into fragments of shiny black glass!!

These "chips" are up to a centimeter wide, say the volcanologist Guido Giordano, the lead author of the new study in Scientific Reports.

When scientists studied the glass using an electron microscope, they discovered an "amazing, truly unexpected thing". 

Complex networks of neurons, axons and other identifiable parts of the man's brain and spinal cord were preserved in the glass, according to the study.

How this happened is something of a mystery.

Glass occurs rarely in nature because it requires extremely hot temperatures to cool very rapidly, leaving no time for crystallization. It is usually caused by meteorites, lightning or lava.

This is even more unlikely to happen to human tissues, because they are mostly made out of water.

The Roman's brain being preserved in glass is the "only such occurrence on Earth" ever documented for human or animal tissue, the study said.

The scientists determined that the brain must have been exposed to temperatures soaring above 510 degrees Celsius (950 Fahrenheit).

That is hotter than the pyroclastic flow that buried the city, which topped out at around 465C.

Then the brain needed to rapidly cool down—and all this had to happen before the flow arrived.

Part 1

Comment by Dr. Krishna Kumari Challa on February 28, 2025 at 9:51am

Brain creates 'summaries' while reading, unlike AI models that process full texts

Unlike artificial language models, which process long texts as a whole, the human brain creates a "summary" while reading, helping it understand what comes next.

In recent years, large language models (LLMs) like ChatGPT and Bard have revolutionized AI-driven text processing, enabling machines to generate text, translate languages, and analyze sentiment. These models are inspired by the human brain, but key differences remain.

A new study, published in Nature Communications, explores these differences by examining how the brain processes spoken texts.

The study analyzed fMRI brain scans of 219 participants while they listened to stories. Researchers compared the brain's activity to predictions made by existing LLMs. They found AI models accurately predicted brain activity for short texts (a few dozen words). However, for longer texts, AI models failed to predict brain activity accurately.

The reason? While both the human brain and LLMs process short texts in parallel (analyzing all words at once), the brain switches strategies for longer texts. Since the brain cannot process all words simultaneously, it stores a contextual summary—a kind of "knowledge reservoir"—which it uses to interpret upcoming words.

In contrast, AI models process all previously heard text at once, so they do not require this summarization mechanism. This fundamental difference explains why AI struggles to predict human brain activity when listening to long texts.

To test their theory, the researchers developed an improved AI model that mimics the brain's summarization process. Instead of processing the entire text at once, the model created dynamic summaries and used them to interpret future text. This significantly improved AI predictions of brain activity, supporting the idea that the human brain is constantly summarizing past information to make sense of new input.

This ability allows us to process vast amounts of information over time, whether in a lecture, a book, or a podcast. Further analysis mapped brain regions involved in both short-term and long-term text processing, highlighting the brain areas responsible for context accumulation, which enables us to understand ongoing narratives.

Refael Tikochinski et al, Incremental accumulation of linguistic context in artificial and biological neural networks, Nature Communications (2025). DOI: 10.1038/s41467-025-56162-9

Comment by Dr. Krishna Kumari Challa on February 28, 2025 at 9:29am

Robot Headbutting Woman Raises Safety Questions

Humanoid robots are supposed to be our loyal assistants, but we saw another side to them the other day.

Chinese robot manufacturer Unitree was demonstrating its latest H1 robots at a lantern festival in the city of Taishan, Guangdong province, when one walked up to the crowd barrier and seemed to lunge at an elderly woman, nearly headbutting her.

Experts are now demanding these things to reduce the danger:

Robots that looks sleek and can dance and flip are fun to watch, but how safe are the audiences?

Safe designs should consider everything from reducing cavities where fingers could get caught, to waterproofing internal components.

Protective barriers or exoskeletons should be added to further reduce unintended contact, while cushioning mechanisms could reduce the effect of an impact.

Robots should be designed to signal their intent through lights, sounds and gestures. For example, they should arguably make a noise when entering a room so as not to surprise anyone.

Operators should be trained well and the public should be educated appropriately.

Comment by Dr. Krishna Kumari Challa on February 28, 2025 at 8:56am

Experts call for ban on toxic chemicals in plastics

Researchers are calling for a substantial reduction in the number of chemicals used in plastics manufacturing, and a complete ban of chemicals known to be detrimental to both human health and the environment—in a new paper published by Cambridge University Press in Cambridge Prisms: Plastics.

Plastics pollution is a major threat to human well-being and planetary health. While plastics recycling is often presented as the answer to plastics pollution, the presence of toxic chemicals in plastics, which enter plastics at various stages of the manufacturing process intentionally and otherwise, means that this is not a viable solution. To address the plastics pollution crisis, the safety and sustainability of plastics manufacturing must be improved.

Policymakers need to make changes to global, regional, and national policies to reduce the toxicity present in the plastics life cycle and address chemicals at each stage of manufacturing.

The researchers identified five policy strategies to support a transition to safer, more sustainable plastics:

Improving reporting, transparency and traceability of chemicals in plastics throughout their full life cycle

Advocating for chemical simplification and group-based approaches to regulating hazardous chemicals

Implementing chemical monitoring, testing and quality control

Creating economic incentives that follow the waste hierarchy

Generating support for a just transition to protect people, including waste pickers, impacted throughout the plastics life cycle.

Plastics contain a vast range of chemicals, including monomers, polymers, processing agents, fillers, antioxidants, plasticizers, pigments, microbiocides and stabilizers—and plastics production has already reached levels that threaten the stability of the Earth's functions. Moreover, the amounts and types of chemicals in plastics products varies, and there are few requirements for transparency and reporting.

We need a compulsory, globally standardized mandate that ensures transparent reporting regarding the chemicals used in plastics, to facilitate a safer and more sustainable reuse, refill, repurpose and recycling market, say the experts.

 Bethanie Carney Almroth et al, Addressing the toxic chemicals problem in plastics recycling, Cambridge Prisms: Plastics (2025). DOI: 10.1017/plc.2025.1

Comment by Dr. Krishna Kumari Challa on February 28, 2025 at 8:52am

High microplastic levels in bird lungs suggest widespread air pollution impact

Microscopic plastic pollutants drifting through the air are lodging in the lungs of birds, a new study finds. Researchers worldwide are increasingly alarmed by how pervasive these harmful particles are in the air humans breathe and the food they eat.

Birds were chosen for the study because they are found in almost every corner of the world and often share environments with humans. Birds serve as important indicators of environmental conditions. They help us understand the state of the environment and make informed decisions about conservation and pollution control.

The researchers  studied 56 different wild birds from 51 distinct species, all sampled from the Tianfu airport in western China. They collected lung samples from each bird and performed two types of chemical analyses.

They used laser direct infrared technology to detect and count microplastics in the birds' lungs. Pyrolysis gas chromatography-mass-spectrometry helped identify even smaller nanoplastics, which can enter the lungs through the bloodstream. Together, the tests allowed scientists to measure the amount of plastic in the birds' lungs and determine the specific types of plastics present.

The study found high concentrations of microplastics in bird lungs, with an average of 221 particles per species and 416 particles per gram of lung tissue. The most common types identified were chlorinated polyethylene, used for insulating pipes and wires, and butadiene rubber, a synthetic material in tires.

While no official "safe" level of plastic particles in lung tissue exists, high levels of microplastics have been linked to serious health conditions, including heart disease, cancer, respiratory problems and fertility issues.

The research highlights an urgent need to address plastic pollution in our environments, as these contaminants can have far-reaching impacts on ecosystem health, as well as human health.

 Mengzhu Wang et al, Assessing microplastic and nanoplastic contamination in bird lungs: evidence of ecological risks and bioindicator potential, Journal of Hazardous Materials (2025). DOI: 10.1016/j.jhazmat.2025.137274

Comment by Dr. Krishna Kumari Challa on February 28, 2025 at 8:37am

Their key findings were that aged smoke is more toxic:

The study found that 4-nitrocatechol was significantly more toxic to lung cells than levoglucosan. At relatively low doses, 4-nitrocatechol reduced cell survival and caused oxidative stress—an imbalance that damages cells and can lead to lung diseases.
Exposure to 4-nitrocatechol disrupted the function of mitochondria in lung cells, leading to a process called apoptosis, or programmed cell death. This damage could contribute to long-term lung problems.
While levoglucosan exposure also led to cellular stress, its effects were much less severe compared to 4-nitrocatechol. Cells exposed to levoglucosan showed signs of mitochondrial stress, but they were able to recover over time.
Since 4-nitrocatechol forms when biomass smoke reacts with urban air pollutants like nitrogen oxides, areas affected by both wildfires and traffic pollution may be particularly at risk.
While wearing an N95 or P100 mask can help filter out fine particles, it may not fully protect against toxic gases and chemicals present in aged smoke. Here are some steps individuals can take:

Use HEPA air purifiers to remove fine particles from indoor air, and keeping windows and doors closed can help minimize smoke infiltration.
Ensure that homes are properly sealed to prevent smoke from entering through cracks, vents or poorly fitted windows and doors; avoid using candles, gas stoves or burning wood indoors, as these can add to indoor air pollution;
In extreme conditions, individuals with respiratory issues or prolonged exposure may consider investing in gas masks with activated carbon filters, which can help remove both particles and harmful gases.
If air quality levels are hazardous and exposure is prolonged, relocating to an area with cleaner air—either indoors with filtered ventilation or to a different location—might be the safest option.
This study reinforces concerns that exposure to biomass smoke—especially aged smoke containing 4-nitrocatechol—can have serious health consequences.
Long-term exposure to these pollutants has been linked to respiratory diseases such as asthma, chronic obstructive pulmonary disease and lung cancer. People who live in wildfire-prone areas or who frequently burn wood for heating should take extra precautions, say the researchers.

Faria Khan et al, Evidence for cytotoxicity and mitochondrial dysfunction in human lung cells exposed to biomass burning aerosol constituents: Levoglucosan and 4-nitrocatechol, Environmental Pollution (2024). DOI: 10.1016/j.envpol.2024.125173

Part 2

Comment by Dr. Krishna Kumari Challa on February 28, 2025 at 8:35am

Aged biomass emissions could pose greater risk to lungs than fresh wildfire smoke

Biomass burning—whether from wildfires, wood stoves or agricultural fires—sends massive amounts of tiny particles and chemicals into the air. These emissions are not just an environmental issue; they pose serious health risks, especially for our lungs.

An Environmental Pollution study reveals how two key components of biomass smoke—levoglucosan and 4-nitrocatechol—affect human lung cells. Their findings suggest that aged smoke, which has undergone chemical changes in the atmosphere, could be even more dangerous than fresh smoke.

Biomass burning refers to the combustion of organic materials like wood, leaves and crop residues. This process releases large amounts of carbon-based aerosols, which contribute to air pollution. Among the many chemicals produced in the smoke, levoglucosan and 4-nitrocatechol serve as important markers.

Levoglucosan is a sugar-like compound released when wood burns, while 4-nitrocatechol forms when smoke interacts with nitrogen oxides in the atmosphere, a process known as chemical aging. While scientists have long studied the environmental effects of biomass burning, less is known about how these compounds directly impact human health.

Researchers used two different types of lung cells: BEAS-2B cells, which represent normal lung-lining cells, and A549 cells, which come from lung cancer tissue and are commonly used in respiratory studies. The researchers exposed these cells to different concentrations of levoglucosan and 4-nitrocatechol over 24 and 48 hours. They then measured cell survival, stress levels and signs of damage to the cells' mitochondria—the "power plants" of cells that generate energy.

Part 1

Comment by Dr. Krishna Kumari Challa on February 27, 2025 at 10:21am

Five common controversial tests in Instagram and TikTok posts
Full-body MRI scan: Claimed to test for up to 500 conditions, yet no evidence of benefit for healthy people, while real dangers exist of unnecessary diagnoses and overtreatment.

Multi-cancer early detection tests: Claimed to screen for more than 50 cancers, yet clinical trials are still underway. As yet, there is no evidence that the benefits of screening healthy populations will outweigh the harms of unnecessary cancer diagnoses.

AMH or "egg-timer" test: While beneficial for certain women, this test is falsely promoted to healthy women as a test for fertility, with concerns the results can lead to unnecessary, costly fertility treatments.

Gut microbiome test: Test promises "wellness" via early detection of many conditions—from flatulence to depression—without good evidence of benefit, alongside concerns that test results could lead to medical overuse, causing harm and waste.

Testosterone test: No evidence of benefit for testing healthy men, yet the danger of overuse of treatments; long-term safety of testosterone therapy, in relation to adverse cardiovascular events and early death, has not yet been established.

 Social Media Posts about Medical Tests with Potential for Overdiagnosis, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2024.61940

Part 3

Comment by Dr. Krishna Kumari Challa on February 27, 2025 at 10:21am

These findings suggest social media is an open sewer of medical misinformation.

This is a public health crisis that exacerbates overdiagnosis and threatens the sustainability of health systems.

A detailed analysis of the results found that posts from medical doctors, posts mentioning scientific evidence, or scientists themselves and posts from influencers with no financial interest in the tests, tended to be more balanced overall. The research group is currently investigating ways to better regulate this type of misleading medical information on social media.

Given that social media platforms like Instagram are moving away from fact-checking their content, the need for stronger regulation to prevent misleading medical information has gained urgency, say the researchers. 

Part 2

Comment by Dr. Krishna Kumari Challa on February 27, 2025 at 10:18am

Study finds influencers promote 'overwhelmingly' misleading information about medical tests on social media

Influencers are promoting "overwhelmingly" misleading information about medical tests on Instagram and TikTok, according to a global University of Sydney-led study published in JAMA Network Open.

Researchers analyzed almost 1,000 posts about five controversial medical screening tests that had been promoted by social media influencers to almost 200 million followers. They found most posts had no reference to scientific evidence, were promotional, had explicit financial interests and failed to mention potential harms.

The tests included full-body MRI scans; genetic testing claiming to identify early signs of 50 cancers; blood tests for testosterone levels; the anti-mullerian hormone (AMH) test which surveys a woman's egg count; and the gut microbiome test. Experts say these tests have limited evidence of benefit in healthy people and could lead to overdiagnosis and overuse.

The vast majority of these posts were overwhelmingly misleading, the study concludes. They are being promoted under the guise of early screening, as a way to take control of your own health. The problem is they are unnecessary for most people and, in some cases, the science backing their efficacy is shaky.

One example is the 'egg timer' or AMH test. It is being heavily marketed to women by influencers as a way of measuring fertility, but experts do not consider it to be reliable. There is the concern that a low result discovered outside the context of a specific medical issue may drive some women to unnecessary, costly fertility interventions.

Another example is the testosterone test, often marketed to men using fear-mongering tactics to then promote testosterone supplements which claim to enhance masculinity and sexual performance. This is risky as the long-term safety of testosterone replacement therapy on cardiovascular health and mortality is still unknown.

One of the underlying themes being used by influencers promoting these tests is that knowledge is power, but most information is cherry-picked. When it comes to health, getting the full picture is so important, and half-truths are often lies.

Among the 982 posts on Instagram and TikTok:

• 87% mentioned the benefits of the tests, yet only 15% mentioned potential harms;
• Only 6% mentioned the risk of overdiagnosis or overtreatment;
• Only 6% mentioned scientific evidence, while 34% used personal anecdotes to promote the test;
• 68% of influencers and other account holders had financial interests in promoting the test (e.g. partnership, collaboration, sponsorship or selling for own profit in some way).

Part 1

The study found 85% of the posts did not mention any test downsides or risks. These tests carry the potential for healthy people to receive unnecessary diagnoses, which could lead to unnecessary medical treatments or impact mental health.

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