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Comment by Dr. Krishna Kumari Challa 2 hours ago

Both very low and very high heart rates are significantly associated with stroke risk, study finds

A study presented at the European Stroke Organization Conference (ESOC) 2026 suggests that both very low and very high resting heart rates are linked with an increased risk of stroke. As the largest population-level study to examine this relationship, the findings challenge the assumption that lower heart rates are always a sign of good cardiovascular fitness and carry no risk.
Both very low (<50 bpm) and very high (≥90 bpm) resting heart rates are independently associated with increased stroke risk, forming a U-shaped relationship, with the lowest risk at 60–69 bpm. This association persists after adjusting for major risk factors and is evident only in individuals without atrial fibrillation. Low heart rates are mainly linked to ischemic stroke, while high rates are associated with both ischemic and hemorrhagic stroke. In an analysis of the UK Biobank, researchers followed 460,000 participants for an average of 14 years, during which 12,290 strokes occurred. Analyses were adjusted for age, sex and cardiovascular risk factors, including atrial fibrillation—a heart condition that causes an irregular heartbeat and is a major cause of stroke. Stroke risk was lowest at resting heart rates of 60 to 69 beats per minute (bpm) but increased at both extremes—below 50 bpm and at or above 90 bpm—forming a clear U-shaped pattern. At these extremes, stroke risk was 25% higher in those with very low heart rates and 45% higher in those with very high heart rates. Importantly, in the overall population, this relationship remained after adjustment for established stroke risk factors including hypertension, diabetes and atrial fibrillation, suggesting it reflects a genuine biological signal. However, when participants were analyzed separately, the pattern was only seen in people without atrial fibrillation. In those with the condition, the relationship was not apparent. This is likely because atrial fibrillation is such a strong risk factor for stroke, increasing risk by around fivefold, that it outweighs the contribution of heart rate and limits our ability to detect its effect. Heart rate was therefore most informative in people without atrial fibrillation, where it may provide a valuable additional tool for identifying and stratifying stroke risk. The researchers also explored the potential mechanisms underlying the relationship between heart rate and stroke. Very low heart rates were primarily associated with ischemic stroke. This would be consistent with the hypothesis that very low heart rates could be associated with reduced blood flow to the brain by prolonging the relaxation phase between heartbeats. In contrast, elevated heart rates were associated with both ischemic and hemorrhagic stroke and may suggest increased stress on blood vessel walls that could contribute to both ischemic injury and a greater predisposition to bleeding.

Penn, D., et al. Reduced and elevated resting heart rates predict risk of stroke, independently of atrial fibrillation: A UK Biobank analysis. Oral presentation. European Stroke Organization Conference (ESOC) 2026.

Comment by Dr. Krishna Kumari Challa 2 hours ago

Early-life chemical exposure may leave extra X and Y chromosomes in sperm

An estimated 7% of all men are affected by infertility. Multiple animal studies indicate that exposure to persistent environmental chemicals in early life can negatively impact male reproductive health, and now a human study suggests the same.
Prenatal and early-life exposure to organochlorines (PCBs) and perfluorinated compounds (PFASs) is associated with increased sperm aneuploidy, specifically extra X and Y chromosomes, in adult men. Elevated PCB levels correlated mainly with additional Y chromosomes, while PFAS exposure was linked to both extra X and Y chromosomes, indicating enduring impacts on sperm genetic integrity.
Normal sperm contain either an X (i.e., the designated chromosome for females) or Y (i.e., the one present in males) chromosome. PCB concentration in blood samples was associated mainly with having an additional Y chromosome, while PFAS exposure was consistently associated with both extra Y and X chromosomes.

Researchers theorize that PCB exposure could be from a maternal diet of contaminated seafood. PFAS exposure was likely due to environmental pollutants in food, water, and air.

Melissa J. Perry et al, In utero and childhood exposure to organochlorines and perfluorinated chemicals in relation to sperm aneuploidy in adulthood, Environmental Health (2026). DOI: 10.1186/s12940-026-01303-w

Comment by Dr. Krishna Kumari Challa 2 hours ago

Masculine behavior bad for the planet says new research

Major new research on climate change, global warming and environmental collapse, how they connect with what men do, and what to do about it has just been published by a research team.
Men generally exhibit higher carbon footprints and environmental impacts, particularly through consumption, travel, and involvement in high-impact industries. They show less concern for climate change and are less likely to support or engage in environmental politics. These patterns are most pronounced among elite men in the global North, though some men actively work to counteract these trends.
The team's findings
Men tend to have a greater carbon footprint and greater environmental impact through consumption, especially travel, transportation, and tourism
Men tend to have less concern with climate change, and less willingness to change everyday practices to ameliorate it
Men tend to be less ambitious and less active in environmental politics, and less supportive of political parties that work for environmental justice
Men tend to be more involved in owning, managing, controlling heavy, chemical, carbon-based, industrialized agriculture, high environmental impact and extractive industries, and of course militarism, with its own devastating environmental effects
These damaging patterns apply especially to elite men in the global North
But some men are working urgently and energetically to change these tendencies.

Kadri Aavik et al, Men, masculinities, and the planet at the end of (M)Anthropocene: ecological/social/economic/political relations, processes and consequences, NORMA (2025). DOI: 10.1080/18902138.2025.2576458

Comment by Dr. Krishna Kumari Challa 3 hours ago

Microplastics pass through earthworms without accumulating in body tissues, study shows
Microplastics ingested by earthworms remain confined to the gut and do not accumulate in internal tissues. Earthworms rapidly eliminate these particles when moved to clean soil, indicating minimal risk of tissue retention. High-resolution imaging confirmed the absence of microplastic translocation beyond the digestive tract. Further research is needed to assess implications for other organisms and humans.

Nicholas V Letwin et al, Assessing the accumulation of microplastics in earthworms (Eisenia fetida) using traditional bioaccumulation modeling and synchrotron-based microcomputed tomography, Environmental Toxicology and Chemistry (2026). DOI: 10.1093/etojnl/vgag072

Comment by Dr. Krishna Kumari Challa 3 hours ago

Coloured microplastics could be making global warming worse

There's more bad news about microplastics. We already know they pose a risk to health and can pollute ecosystems, but now researchers have discovered that tiny plastic particles drifting in Earth's atmosphere could be a significant contributor to global warming.
According to a paper published in the journal Nature Climate Change, airborne microplastics trap nearly one-fifth as much heat as black carbon, also known as soot.
Researchers found that coloured microplastics and nanoplastics absorb much more sunlight than previously estimated. While white particles mostly scatter light, darker shades like blue, red, and black can absorb up to 74.8 times more sunlight than uncoloured plastic. The problem with this is that the particles then convert that energy into heat in the air around them.
The study revealed that the global average warming effect (direct radiative forcing, or DRF) from these particles is 0.039 watts per square meter. "Colored MNPs intensify DRF by 15.3-fold compared with non-pigmented particles," write the paper's authors. In some parts of the world, such as the North Pacific Subtropical Gyre circulation, their warming effect was found to be nearly five times that of local soot.
The scientists add, "MNPs emerge as dual-threat climate forcers, simultaneously driving radiative heating and carbon budget perturbations."

Yu Liu et al, Atmospheric warming contributions from airborne microplastics and nanoplastics, Nature Climate Change (2026). DOI: 10.1038/s41558-026-02620-1

Comment by Dr. Krishna Kumari Challa 3 hours ago

At first, swapping in a similar building block worked only about 43% of the time. To improve this, the researchers turned to AI, which helped them select the best replacement for a missing amino acid based on its surrounding context, ensuring the protein didn't fold incorrectly or collapse. They redesigned ribosomes that were capable of producing 52 Ile-free proteins. They eventually combined 21 of these redesigned parts into a single E. coli strain, which they named Ec19.

The results showed that the so-called universal 20-letter (amino acid) code of life isn't an absolute requirement for survival, and it is indeed possible to create a living organism that gets by with just 19 amino acids.

The researchers noted that as genome-scale modeling and DNA synthesis improve, scientists will be able to test many engineered genomes by swapping amino acids, creating cells with new traits and pushing the limits of synthetic biology.

Liyuan Liu et al, Toward life with a 19–amino acid alphabet through generative artificial intelligence design, Science (2026). DOI: 10.1126/science.aeb5171. www.science.org/doi/10.1126/science.aeb5171

Part 2

Comment by Dr. Krishna Kumari Challa 3 hours ago

Engineered bacteria break the 20-amino-acid rule

There are over 500 different types of amino acids found in nature, yet protein synthesis in life forms uses only the canonical 20. Some bacteria are known to use extra amino acids, bringing the total to 21 or even 22, but no naturally occurring organism has been found that uses fewer than these 20 amino acids. Large-scale genetic studies are a testament to it.

One of life's many mysteries is how it ended up choosing only a set of 20 amino acids to build proteins for its wide catalog of organisms, from single-celled bacteria to behemoth whales. From a chemical standpoint, many of the canonical amino acids share similar chemical structures and properties, which might make them expendable. This raises an intriguing question: could life manage with one less amino acid?

In a recent study in Science, researchers used generative AI and deep-learning models like AlphaFold2, which can predict protein 3D structures, to design Ec19 —a genetically engineered strain of E. coli that functions using just 19 amino acids instead of the usual 20.

In Ec19, the researchers set out to see if they could remove isoleucine (Ile) and still obtain a living, healthy cell. The resulting strain remained genomically stable and grew at nearly the same rate as normal bacteria for over 450 generations in the laboratory, and whole-genome sequencing found no evidence of Ec19 attempting to restore Ile and revert to the 20-amino acid system.

Scientists also suggest that before the single-celled organism considered our last universal common ancestor (LUCA), early life forms likely used a smaller set of amino acids than the one we see today. Since many canonical amino acids have similar biochemical properties, their role might be redundant.

Computational studies have suggested that as few as 9 to 12 amino acids may be enough to build almost every known protein shape. Even the cell's own protein-making machinery isn't perfect, where every so often it slips, and about 8% of proteins end up with at least one wrong amino acid. Yet most of them still work just fine.
For this study, the researchers began by analyzing the 20 amino acids to determine which one was most replaceable, and isoleucine (Ile) emerged as a contender because it is chemically very similar to another amino acid, valine. So they followed a careful step-by-step approach known as the design-build-test framework to see if they could create a living cell that functions without the amino acid Ile.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

People who are blind from birth never develop schizophrenia—what this tells us about the psychiatric condition
Congenital cortical blindness appears to confer strong protection against schizophrenia, with no reported cases among individuals blind from birth due to visual cortex damage. This protection is not seen in those who lose vision later or have blindness from eye damage, suggesting early absence of visual input alters brain development and prediction processes implicated in schizophrenia. Insights from this phenomenon may inform new approaches targeting perception and brain organization in schizophrenia treatment.

https://www.frontiersin.org/journals/psychology/articles/10.3389/fp...

original article.

Comment by Dr. Krishna Kumari Challa yesterday

Why your face doesn't perceive itchiness the same way your body does

In a new study, researchers show that itch sensations in the face are perceived differently from those in the body due to differences in signalling between trigeminal (located in the brain) and spinal pain pathways. The work could lead to the development of specific molecular targets for treating facial pain or itch. The study appears in Communications Biology.
On the body, itch signals go from neuronal projections in the skin through the dorsal root ganglia (DRG)—which are clusters of sensory cells located at the root of the spinal nerves—then to the spinal cord. But on the face and head, those signals travel to the trigeminal ganglia (TG)—which are clusters of sensory cells located in a small structure below the brain where it sits atop the skull."

We know that in terms of itch, the face and torso have different thresholds—in mice, for example, they have lower itch response to histamine exposure on the cheek as compared to the nape of the neck.
The researchers first looked at itch response in mice exposed to histamine on the cheek and nape. They observed that itch response on the cheek was significantly reduced when compared with the neck. Next, they looked at innervation—or how many nerves were present—in the face versus the neck to rule out structural causes for the difference in response.

Finally, they looked at the neuronal populations within the DRG and TG, and the neuropeptides they express.

The neurons within the DRG and TG differ, mainly because the sensory environments they work in differ. Skin doesn't need to be able to sense taste or smell, for example. But it also seems as though the neuronal populations don't handle signals the same way, either.

Wheeler, J.J. et al, Substance P and somatostatin neurons limit facial itch by recruiting distinct nociceptive circuits in the brainstem, Communications Biology (2026). DOI: 10.1038/s42003-026-10128-9 www.nature.com/articles/s42003-026-10128-9

Comment by Dr. Krishna Kumari Challa yesterday

A 'living plastic' activates and self-destructs on command

A living plastic incorporating dormant Bacillus subtilis spores and two cooperative polymer-degrading enzymes fully degrades polycaprolactone into monomers within six days upon activation with nutrient broth at 50 °C, without generating microplastics. The material retains mechanical properties similar to conventional polycaprolactone and demonstrates potential for programmable, on-demand biodegradation in various plastic types.

Chenwang Tang et al, Degradable Living Plastics Programmed by Engineered Microbial Consortia, ACS Applied Polymer Materials (2026). DOI: 10.1021/acsapm.5c04611

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