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Comment by Dr. Krishna Kumari Challa 13 hours ago

Tiny marine microbe sheds new light on how little genetic machinery a cell needs to survive
The marine archaeon Candidatus Sukunaarchaeum mirabile has 189 protein-coding genes, retaining machinery for DNA replication and protein synthesis. It lacks nearly all genes for nutrient and energy production, suggesting strong dependence on other organisms. It has not been directly observed, and its host and possible parasitic lifestyle remain unknown.

A hidden archaeal lineage with an ultra-reduced genome retaining only its replicative core, Current Biology (2026). DOI: 10.1016/j.cub.2026.09.042. www.cell.com/current-biology/f … 0960-9822(26)01251-0

Comment by Dr. Krishna Kumari Challa 14 hours ago

Strong magnetic fields could allow white dwarfs to grow beyond the Chandrasekhar limit

When a dying star runs out of fuel and sheds its outer layers, its remaining core can become an approximately Earth-sized, extremely dense stellar remnant called a white dwarf. For a white dwarf that is not strongly rotating or magnetized, there is a well-known upper mass limit of about 1.4 times the mass of the sun, known as the Chandrasekhar limit.
As a carbon-oxygen white dwarf approaches this limit, its core can become dense enough to ignite carbon, potentially triggering a thermonuclear explosion known as a Type Ia supernova.

If the Chandrasekhar limit is fixed, the supernova energy release rate and luminosity should be fixed. Scientists have used this constancy of luminosity to understand the evolution and size of the universe, which is presently thought to be expanding.
Now, simulations by researchers from the Department of Physics at the Indian Institute of Science (IISc) and collaborators show that strong internal magnetic fields could allow some white dwarfs to grow to substantially higher masses than the Chandrasekhar limit allows. In one of their simulations, the researchers found that a magnetized carbon-oxygen white dwarf can reach about 2.4 times the mass of the sun—well above the limit.
Stellar evolution simulations predict that magnetic pressure can support accreting carbon–oxygen white dwarfs up to about 2.4 solar masses, exceeding the usual 1.4-solar-mass Chandrasekhar limit. Accretion-driven contraction strengthens internal magnetic fields, providing additional support against gravity.

Zenia Zuraiq et al, Super-Chandrasekhar White Dwarfs by the Evolution of Magnetized Main-sequence Stars: New Mass Limits from STARS Simulation, The Astrophysical Journal Letters (2026). DOI: 10.3847/2041-8213/aea97e

Comment by Dr. Krishna Kumari Challa 14 hours ago

Bees struggle to smell flowers when air pollutants combine

Bees, moths and other pollinating insects have a harder time smelling flowers in polluted air, according to new research.
Scientists analyzed 22 experimental studies on how the air pollutants ozone and nitrogen oxides (NOx) affect pollinators. Both pollutants make it harder for pollinators to find flowers by breaking down or altering the scents that flowers give off.
The new research, published in the journal Frontiers in Ecology and the Environment, found that elevated ozone reduced pollinator performance by an average of 42%, while NOx cut performance by 46%. When the two pollutants occurred together, the average reduction was 68%.

Only a few studies tested both pollutants together, and in those the extra harm from combining them was smaller than the averages suggest. This is because the two gases react with each other in the air and partly cancel each other out.
The study also found specialist pollinators reliant on one plant's scent, such as some moths, are more at risk than generalists like many bees. Additionally, day-active pollinators such as bees and butterflies face higher ozone levels, while night-active pollinators (including many moths) encounter higher nitrogen oxides. Both need protection.

Pollinator risks and recovery from air pollutant interactions during the fossil fuel transition, Frontiers in Ecology and the Environment (2026). DOI: 10.1002/fee.70076

Comment by Dr. Krishna Kumari Challa yesterday

Sweat contains amino acids and other compounds that can interact with metals. The researchers added cysteine, an amino acid containing sulfur, to an artificial sweat solution and exposed the earrings to it for 168 hours at about 30 C (86°F). The team then measured the metals released into the solution using highly sensitive mass spectrometry, a scientific technique used to weigh molecules.

There is no standard artificial-sweat test specifically designed to capture how gold behaves in the presence of sulfur, so Hedberg added cysteine to the solution to create conditions that would reveal whether gold could become soluble.

The experiment was designed around a simple chemical principle. For a metal to cause an allergic response, it first has to become chemically available.
Gold was detected in the release solution from all five pairs of earrings.

Only tiny amounts of gold were released over the weeklong test, with a median of 0.057 micrograms per square centimeter. The amount varied among the earrings, ranging from 0.016 to 0.15 micrograms.

Copper was released in much greater amounts, exceeding gold in every sample. The median copper release was 0.53 micrograms per square centimeter per week. Copper is generally considered harmless for humans and has beneficial antibacterial properties. Its higher release was expected, since the earrings were alloys, meaning gold was combined with other metals. Surface analysis showed the materials consisted mainly of gold, copper, silver and zinc, with only small amounts of nickel detected at the surface.
None of the five pairs of jeweler-purchased earrings released detectable nickel under the conditions of the new experiment.

Gold-plated jewelry can have a thin gold coating over one or more underlying layers that may contain nickel. In the earlier study on inexpensive earrings, nickel was detected in the artificial sweat in which all 10 inexpensive gold-plated earrings were tested.
For the jewelry-store earrings, element-specific spectroscopy showed gold throughout the material, rather than just a thin surface coating, while the Temu earrings, if they contained any gold, had only a thin layer of plating.
The study measured how much gold became soluble (able to dissolve in a liquid) under specific laboratory conditions. It did not measure how much gold reaches or remains on a person's skin during actual wear, nor does it establish a dose at which gold jewelry triggers dermatitis.

Hedberg says the very small amounts of gold detected in the study would probably not be enough to trigger an allergic reaction in most circumstances. But that does not make the result irrelevant to someone who already knows they are allergic to gold.
For most people, however, nickel remains a more immediate concern with inexpensive jewelry, rather than gold.

Mikkel Bak Jensen et al, Gold and Nickel Release From Gold‐Plated Earrings Under Cysteine‐Modified Artificial Sweat Conditions, Contact Dermatitis (2026). DOI: 10.1111/cod.70187

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Allergic to gold jewelry? Lab tests reveal gold can dissolve from earrings under specific chemical conditions
Gold has a reputation for being chemically untouchable. But according to chemists that reputation is a little misleading—gold is not unreactive so much as selective about what it reacts with.

Every material has its own enemy. Its own kryptonite. For gold, one of those enemies is sulfur.
When researchers tested five pairs of 10K and 14K gold earrings purchased from a jeweller, all five pairs of 10K and 14K gold earrings released gold after one week in cysteine-containing artificial sweat, with a median release of 0.057 micrograms per square centimeter. Nickel release was undetectable. Gold can become soluble under these conditions, but the results do not establish exposure during wear or a dose that triggers allergy.

After a week in cysteine-modified artificial sweat, all five pairs released measurable amounts of gold. Cysteine is an amino acid, or protein building block, made naturally by the body that contains sulfur, which binds to gold.

The amounts were tiny, and the findings do not show that the released gold is enough to cause an allergic reaction. But the study, published in the journal Contact Dermatitis, demonstrates that gold in jewelry can become chemically available under the right conditions—a finding that helps explain how exposure to gold can occur at the skin.
Gold, silver and platinum are known as noble metals because they do not readily react with oxygen. That resistance to oxidation is a big part of gold's reputation for stability. But it does not mean the metal is universally unreactive.
Gold reacts to different things.
Gold doesn't react much with oxygen, but it can react with sulfur and some amino groups. And for some people, that reaction poses a problem.
Gold allergy is real, although it is less common than nickel allergy. But for a metal to trigger an allergic response, some of that metal has to become chemically available to the body.
Part 1

Comment by Dr. Krishna Kumari Challa on Thursday

Scientists win chemistry Nobel for discoveries about mirrored molecules that led to many drugs
Developed chemical reactions demonstrate how homochirality can emerge spontaneously. Homochirality involves molecules sharing the same handedness rather than an equal mixture of mirror-image forms.
Scientists Henri B. Kagan and Kenso Soai won the Nobel Prize in chemistry this week for untangling mysterious mirror images in molecules, a discovery that has been used to develop countless drugs and transformed modern medicine.
Many molecules come in versions that look alike but are not exactly identical, like right and left hands. Kagan, who is from France, and Soai, from Japan, found ways to make chemistry pick a side, describing and designing reactions to produce the desired mirror image.

"The medicines we have today would not be possible without this chemistry".
The discovery enabled most modern medicines
Mirror images of the same molecule can have different properties. For example, one version of the chemical carvone smells like mint, while the other has a whiff of caraway, a spice often used in rye bread.
The alternate versions can also behave differently when interacting with other chemicals. When designing drugs to treat diseases, scientists are choosy about which mirror image they use. They want the version of a molecule to treat a cold, not one that will make the sniffles worse.

In the 1980s, Kagan's work showed there might be a way to design reactions to produce one form of a molecule over the other. Years later, Soai perfected the process. He created the first-ever chemical reaction to efficiently produce only one of a molecule's mirror images, in what's now known as the Soai reaction.

Comment by Dr. Krishna Kumari Challa on Thursday

194-year-old tortoise reveals stable gene switches that may help resist aging

Researchers studying a giant tortoise named Jonathan say it's not just good genes but a lack of genetic wear and tear that has kept him going for nearly two centuries.

An estimated 194-year-old giant tortoise carried 287 unique gene variants linked to DNA repair, inflammation, insulin regulation and cancer suppression. Epigenetic regulation of DNA repair and metabolism resembled that of younger tortoises, indicating limited age-associated changes in these pathways.
In a study published in the journal Science Advances, scientists have pinpointed 287 unique gene variants in this remarkably old giant tortoise that reduce the usual effects of aging. These control key processes in the body, including repairing DNA damage, reducing inflammation, regulating insulin and suppressing cancer.

Jonathan, an Aldabra giant tortoise (Aldabrachelys gigantea), is estimated to be 194 years old. This makes him the oldest living giant tortoise and the oldest land animal in the world today. He's thought to have hatched in 1832—making him a contemporary of Charles Darwin .

The team also compared the giant tortoise's epigenome—the "on/off" switches on his genes—with those of younger giant tortoises of the same species. Remarkably, they found the switches controlling Jonathan's DNA repair and metabolism genes were very similar to those in his younger relatives. Usually, the epigenome changes over time, contributing to the aging process—this is a key reason why things start to go wrong in older bodies.
Researchers found that the gene regulators involved in energy production and DNA repair have remained incredibly stable in Jonathan over almost two centuries.

Benjamin Vaisvil et al, Epigenetic insights into extreme longevity in the world's oldest terrestrial animal, Jonathan, Science Advances (2026). DOI: 10.1126/sciadv.adw8887. www.science.org/doi/10.1126/sciadv.adw8887

Comment by Dr. Krishna Kumari Challa on Thursday

Cricket's day-night pink ball not always so pretty

A new study has found that players with colour vision deficiency (CVD) struggle to see the pink ball around dusk or against the crowd and grass.

Color blindness affects about 8% of men (1 in 12) and 0.5% of women (1 in 200) globally
Spectral modelling indicates that pink cricket balls can be harder to see with colour vision deficiency, depending on lighting, background and ball condition. Red balls generally provide more consistent and equitable visibility, though no ball is optimal in every setting. Injuries and on-field performance were not measured.
Cricket balls are hard and travel very fast, so anything that makes them harder to see warrants attention. We also need to consider whether the choice of ball places some players at a greater disadvantage than others.

Peter M. Allen et al, Not So Pretty in Pink: Computational Modelling of Cricket Ball Visibility with Colour Vision Deficiency, Sports Medicine (2026). DOI: 10.1007/s40279-026-02518-0

Comment by Dr. Krishna Kumari Challa on Thursday

IVF-conceived babies had a higher overall proportion of L-1 DNA in their genomes than naturally conceived babies, a statistically significant difference. This difference was also seen in all three sibling pairs studied. When the researchers examined the surrounding base pairs, they found a high concentration of genes linked to metabolic conditions, cardiovascular diseases, neuropsychiatric disorders and cancer development.

The levels of L-1 DNA did not differ significantly between children conceived through standard IVF and those conceived through ICSI.

This study sheds fresh light on a possible genomic mechanism that may connect the embryonic stress of in vitro fertilization (IVF) to a higher risk of disease. The findings make a strong case for further research on ways to optimize IVF protocols so that embryonic stress and its consequences for the genome can be kept as low as possible.

Jian Li et al, In vitro fertilization–conceived offspring exhibit altered Long Interspersed Nuclear Elements-1 retrotransposition dynamics associated with long-term disease risks, American Journal of Obstetrics and Gynecology (2026). DOI: 10.1016/j.ajog.2026.05.005

Part 2

Comment by Dr. Krishna Kumari Challa on Thursday

IVF-conceived children show more 'jumping gene' DNA, study finds

Infertility affects more than 15% of couples worldwide. Thanks to medical science, infertility treatments have come a long way over the past few years. For millions of people, in vitro fertilization (IVF) has opened a medical pathway to having biological children. This procedure gives fertilization a helping hand outside the body. It involves retrieving eggs from the ovaries and fertilizing them with sperm in a laboratory to create embryos.

Despite its benefits, IVF has also raised questions about the long-term health of children conceived through the procedure. Large epidemiological studies have found that these children have a slightly higher risk of developing certain health conditions later in life.

A recent study published in the American Journal of Obstetrics and Gynecology examined whether the stress embryos experience during IVF laboratory procedures could alter how certain DNA elements move within the genome, potentially putting babies conceived through the process at higher risk of these long-term health conditions.

IVF-conceived babies had a higher overall amount of LINE-1 (short for Long Interspersed Nuclear Elements-1) DNA in their genomes compared with naturally conceived babies. Most of our DNA stays in one place, but LINE-1 (Long Interspersed Nuclear Element-1) is part of a family of transposable elements that can remodel the human genome. These jumping genes can copy themselves and insert those copies into new locations, and this movement showed up at specific points in the genome.

Researchers found 11 locations where the two groups differed in how often LINE-1, or L-1, was inserted and 14 where they differed in how often it was deleted. Genes located near these sites have been linked to metabolic conditions and cancer.
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