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Comment by Dr. Krishna Kumari Challa 18 minutes ago

The potential real-world consequences of following viral skin care trends were highlighted in a separate observational study presented at the EADV Congress 2026. The study involved 94 patients who developed a new or aggravated skin condition following the use of cosmetic or dermatological products promoted on social media.

Chemical exfoliants containing alpha-hydroxy acids (AHAs) or beta-hydroxy acids (BHAs) were the most frequently implicated products, reported in 34% of cases, followed by over-the-counter retinoids (27%), vitamin C serums (14%) and niacinamide-containing products (11%).

Almost half (48%) of patients had adopted complete skin care routines directly inspired by social media content, while 63% were simultaneously using more than three active skin care ingredients.
Many patients were reproducing complex skin care routines involving several active ingredients simultaneously, often based on advice from nonmedical influencers.
Reactions ranged from irritant contact dermatitis (42%) and acne onset or significant worsening (28%) to rosacea flares or rosacea-like dermatitis (12%), post-inflammatory hyperpigmentation (11%) and superficial chemical burns (7%).

Combining several active ingredients can place excessive stress on the skin barrier since some have overlapping irritant effects.
The researchers stressed that Korean skin care itself is not the problem. Rather, the concern is that skin care principles such as gentle cleansing, hydration and barrier care can be transformed on social media into viral, one-size-fits-all routines without appropriate safety information.

Consumers should be cautious of content promising instant or universal results.
Anyone with an existing skin condition who develops irritation or is unsure whether a routine is appropriate for them should seek advice from a dermatologist.

Comment by Dr. Krishna Kumari Challa 20 minutes ago

Almost 95% of viral Korean skincare and 'glass skin' TikTok videos contain misleading claims, new study shows
Among 38 viral TikTok videos on Korean skincare and “glass skin,” nearly 95% contained potentially misleading claims, and safety guidance was largely absent. All were rated unreliable or less reliable. Among 94 patients with skin problems after using social media-promoted products, 63% used more than three active ingredients; irritant contact dermatitis was most common (42%).
Almost 95% of the videos contained at least one misleading claim, while 84% failed to account for different skin types, 45% promoted excessive combinations of active ingredients without appropriate safety guidance and 32% promised instant results.
Consistently basic safety information was absent in these calims.
All videos were classified as unreliable or less reliable, while none cited an external source or reference. Nearly 82% were created by nonphysician influencers, 11% by beauty brands and 8% by other beauty content creators; none were produced by dermatologists.
The findings show a clear gap between the popularity of this content and the quality of the information provided.
Following these routines without individualized guidance may contribute to irritation, over-exfoliation, acne flares or skin barrier disruption, particularly when multiple active ingredients are combined.
Part 1

Comment by Dr. Krishna Kumari Challa 25 minutes ago

Gut bacterial compound worsens brain injury after stroke, study suggests

How much damage a stroke causes in the brain depends strongly on how quickly blood flow can be restored. The patient's own immune response that follows the stroke also plays an important role.

Researchers have discovered how a metabolite produced by gut bacteria can influence brain damage after stroke. Their paper is published in the journal Cell.

They have now identified a specific bacterial signal that shapes this immune response and influences stroke outcome.
Gut bacterial indole worsened brain injury after stroke in mice through AHR signaling in dendritic cells. Disabling AHR in these cells promoted protective immune responses and reduced injury. In patients with ischemic stroke, higher bacterial TnaA abundance was associated with poorer functional outcomes.

The researchers found that in mice with severe stroke, gut bacteria capable of producing indole, a metabolite that is only produced in the gut, become more abundant. These bacteria carry the gene tnaA, which allows them to convert the amino acid tryptophan, found in food, into indole. In mice, the team showed that indole-producing bacteria worsened brain injury after stroke.

Indole acts on a receptor called AHR (aryl hydrocarbon receptor), found in dendritic cells—immune cells that patrol the intestinal lining and help coordinate immune responses. When the researchers switched off AHR specifically in dendritic cells, mice were better protected against brain injury.

Dendritic cells have long extensions, like arms, that allow them to sense changes in their environment, including metabolites produced by gut bacteria. When scientists switched off AHR, the behaviour of these cells changed completely: Dendritic cells were better able to migrate from the intestine to the meninges, the membranes surrounding the brain. These dendritic cells also promoted protective T cells and helped reduce the damage in the brain.
The researchers also found evidence that this pathway may be relevant in humans. In a cohort of human patients with ischemic stroke, the ISD team found that a higher abundance of bacterial TnaA was associated with poorer functional outcomes.
The findings raise an important question for future research: Could changing the gut microbiome or the metabolites it produces in healthy individuals help prepare the immune system to respond differently if a stroke occurs?

Rosa Delgado Jiménez et al, Gut microbiota primes stroke severity via the AHR in intestinal dendritic cells, Cell (2026). DOI: 10.1016/j.cell.2026.09.013

Comment by Dr. Krishna Kumari Challa 2 hours ago

The biological clock regulates phases of wakefulness

The circadian clock is an internal biological system that regulates sleep-wake cycles, as well as many physiological functions such as body temperature and hormone production. In many animals, this clock relies on a network of neurons that generates rhythms of approximately 24 hours.
These neurons must then transmit this information to other regions of the brain, allowing activity and behaviour to be adapted to the time of day.
A circuit linking the biological clock to wakefulness
Imaging techniques that measure neuronal activity allowed researchers to show that this activity varies throughout the day. They identified a connection between the biological clock neurons and a population of neurons that produce dopamine, a molecule that enables neurons to communicate with one another.
Researchers observed that the clock neurons inhibit these dopaminergic neurons, which in turn stimulate neurons in the mushroom body. This brain region plays a role in learning, memory and the regulation of sleep, and its activity contributes to promoting wakefulness during the day
When the clock neurons inhibit the dopaminergic neurons, the wake-promoting signal decreases. Conversely, when this inhibition is released, the dopaminergic neurons can more strongly stimulate the mushroom body and promote wakefulness. Through its neurons, the biological clock can therefore transmit information about the time of day to a brain circuit involved in regulating sleep and wakefulness.

These findings shed light on how the biological clock influences sleep and wake states. In particular, they highlight the central role of dopamine in promoting wakefulness and show how information from the biological clock is relayed through different neural circuits throughout the day.

Disruptions of the circadian clock are associated with various sleep disorders and alterations in brain function. A better understanding of these fundamental mechanisms could ultimately help explain how disturbances in biological rhythms affect the brain.

Blanca Lago Solis et al, Circadian control of dopaminergic signaling to the mushroom body regulates sleep through rhythmic Pka-C1 transcription in Drosophila, Current Biology (2026). DOI: 10.1016/j.cub.2026.09.014

Comment by Dr. Krishna Kumari Challa yesterday

Skipping sweets during antibiotic treatment may help protect the gut microbiome

A new study by researchers suggests eating less sugar could protect the microbiome during antibiotic treatment. The study followed patients with blood cancer undergoing an intensive treatment called allogeneic hematopoietic cell transplant, a population at particularly high risk for severe gut microbiome disruption and associated side effects.

In stem cell transplant patients taking broad-spectrum antibiotics, each additional 100 g of sweets was associated with 24% lower gut bacterial diversity. High-sucrose diets promoted Enterococcus overgrowth in antibiotic-treated mice.
Published in Nature, the findings connect to the idea of "food as medicine" during cancer care and the ways diet can help us prevent and recover from illness. The research could lead to new treatment strategies for cancer patients and potentially others taking antibiotics.

Antibiotics disrupt the diversity of our gut bacteria, or microbiomes, which play an essential role in supporting our immune systems and overall health.
This new research supports emerging evidence that avoiding sugary foods during antibiotic treatment may protect the microbiome. Preserving microbiome diversity has previously been linked with improved clinical outcomes for patients with cancer.
Antibiotics are used to treat infections, but they also broadly destroy good bacteria in the gut, allowing harmful microbes to overgrow.

The five-year study, one of the largest of its kind, followed patients who were hospitalized for several weeks to receive intensive chemotherapy, sometimes with radiation, to wipe out their immune systems before undergoing a stem cell transplant.

To prevent and treat infections, each patient took at least one antibiotic during their hospital stay. Some 80% took one or more broad-spectrum antibiotics, which have the strongest effect on the microbiome because they target many types of bacteria.

The research team tracked 9,419 meals eaten by 173 hospitalized patients and profiled microbiome diversity in stool samples from 158 patients. Microbiome diversity is a key indicator of a healthy microbiome.

Using a variety of advanced statistical models, the researchers searched the data for patterns linked to injury to the gut microbiome.

What they found surprised them.
The patients who consumed more sweets while taking antibiotics were more likely to experience a loss of microbiome diversity as aggressive microbes crowded out other strains of bacteria.

One organism stood out: Enterococcus. When it takes over the microbiome, patients undergoing transplant face a higher risk of bloodstream infections, graft-versus-host disease and other life-threatening complications.

The combination of high-sugar foods and broad-spectrum antibiotics appeared to multiply injury to the microbiome, leading to a 24% drop in bacterial diversity for every 100-gram (3.5-ounce) increase in sweets (equivalent in sugar content to a large milkshake).
The researchers also tested their hypothesis that sugar exacerbates microbiome injury by giving broad-spectrum antibiotics to healthy mice and feeding them a variety of diets. Mice that ate a high-sucrose diet quickly developed an overgrowth of Enterococcus in their guts. Mice that ate the high-sugar diet without antibiotics, however, maintained normal bacterial diversity.

Jonathan Peled, Sugar-rich foods exacerbate antibiotic-induced microbiome disruption, Nature (2026). DOI: 10.1038/s41586-026-11077-3. www.nature.com/articles/s41586-026-11077-3

Comment by Dr. Krishna Kumari Challa yesterday

Research shows poor mental health among politicians may impair decision-making

Longitudinal data from UK and international MPs link psychological distress with lower confidence in political decision-making and differences in how MPs assess choices and risks. The findings support better mental health support for representatives and safeguards for major decisions, but do not establish causation.

James Weinberg et al, The inner cabinet: how mental health impacts political decision-making, Parliamentary Affairs (2026). DOI: 10.1093/pa/gsag038

Comment by Dr. Krishna Kumari Challa yesterday

We don't actually know how many species there are on Earth. Estimates range from 8 million to 20 million. Scientists have identified only 1.5 million to 1.7 million, with around 16,000 new ones added to the list every year.

Some animals are tiny, live in hard-to-reach places or closely resemble known species.
Roughly half of known beetle species are so rare that they have been identified from a single specimen—the only one ever found. Identify it, and it's probably the last time you'll see it.
Given how quickly species are going extinct, the search has become a race against time.

"The assumption is we're losing ones we don't know about yet".
Why is it important to formally identify new species?

New discoveries, such as the recent revelation of Leopardus tilcayo, as "a wonderful reminder of how much remains unknown."
We cannot protect or fully appreciate what we have not yet recognized or understood.
Moreover, a population may look healthy only because scientists have lumped it together with its relatives.

"That's the real importance of recognizing a species from a subspecies".

Jonas Lescroart et al, Phylogenomics and museomics reveal five distinct species of tiger cats in South America, Current Biology (2026). DOI: 10.1016/j.cub.2026.08.059

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

How do scientists determine what counts as a separate species?
Sometimes one glance is all it takes.

You see a zebra and a giraffe, and they look completely different.
But this method doesn't always work with cats.

They say all cats look the same in the dark, and the tilcayo and its close cousins are no different. Even in broad daylight, they all resemble "a bunch of little leopard-spotted cats". Felines as a whole share a surprising number of physical traits.
Once nature reaches perfection, it only tweaks a little.
When animals look alike, scientists need a different way to determine where variation within one species ends and another begins. One way is by looking at reproduction. Can the animals breed, and can their descendants do the same?

In recent decades, scientists have increasingly turned to genetic analysis when asking whether a population forms its own recognizable branch on the evolutionary tree.

Even within the same species, DNA varies a bit. As populations adapt to different environments, however, traits that give them an advantage take root. They make the genetic differences between groups more pronounced over time.

Scientists compare these differences and use statistical methods to decide when a genetic signature becomes a sign of a separate species.

How are new species discovered?
Decades ago, scientists collected specimens in the field and compared them to known animals.
While expeditions still happen, DNA technology has given scientists a new way to spot differences that aren't visible to the eye.

That said, there's a difference between a species being scientifically identified and a species being known.
For example, local communities were aware of the tilcayo for generations.

It's also important to remember that nature doesn't pause to file paperwork when one species becomes two. Instead, it's an ongoing process. Scientists use the concept of subspecies to mark groups in transition.
New species also form when animals from different groups interbreed, producing descendants that follow a separate evolutionary path.

That's exactly what's going on in the case of tiger cats.
in southern Brazil, two of five existing species—Geoffroy's cats and Atlantic Forest cats—are interbreeding as they adapt to human-altered landscapes. This is allowing scientists to watch a sixth species emerge in real time.

"We're seeing evolution in action" .

Part 1

Comment by Dr. Krishna Kumari Challa on Wednesday

Now, Shyamsundar is investigating how nanoparticles can be used to improve cancer treatments. Traditional chemotherapy attacks cancerous and healthy cells, often causing severe side effects. By designing nanoparticles that can better exploit the acidic tumour microenvironment for drug release, she hopes to improve the delivery of chemotherapy drugs to cancer cells while reducing damage to healthy tissue.

To do this, she uses the nanoparticle core as an anchor for molecules—known as a ligand shell—that can regulate what is released and when. The shell resembles a pom-pom, with strings that can both protect the drug and treat cancer depending on the environment they enter. By changing the chemistry of these anchored molecules, she can more precisely tune drug release.
She also investigated factors affecting the formation of lipid nanoparticles for vaccine delivery. She wants to combine her expertise from academia and industry to develop a broader understanding of nanoparticle drug delivery systems.
For her efforts, Shyamsundar earned the Lois Jean Durham Scholarship, which recognizes excellence in chemistry and biochemistry.

The shell hides the drug when the nanoparticle is in the chemical environment of healthy cells, but when it reaches the acidic environment near cancer cells, the particles spring into action.

Changing ligand shell behaviour has the potential to make a big impact on how the drug releases.

I am impressed!

Kaveen Tennakoon et al, Isolating Ligand Steric Effects on Metal Ion Reduction and Gold Nanoparticle Formation Pathways Using Au(I)–Phosphine Complexes, Langmuir (2026). DOI: 10.1021/acs.langmuir.6c02684

Comment by Dr. Krishna Kumari Challa on Wednesday

Researcher solves a nanoparticle mystery using an iPhone camera

We complain about lack of equipment.
Then we use our phones to take selfies and make reels.

But what do intelligent people do?
Read this story to know.

Instead of capturing a memory with an iPhone camera, Carnegie Mellon University's Nivedita Shyamsundar used hers to make a scientific discovery. A senior in the Department of Chemistry, Shyamsundar studies tiny particles that could help medicines and vaccines travel more effectively through the human body and reach their targets. Her work may one day lead to better cancer treatments and stronger vaccines.
She worked with researchers to create new metal nanoparticles. But the researchers could capture only the final stages of nanoparticle formation.

The formation was happening way too fast to capture with typical lab technologies.
The researchers noticed that the solution changed color as the nanoparticles formed. Shyamsundar recorded a reaction with her iPhone. By analyzing the video frame by frame, she tracked the timing of the color changes and compared those observations with the lab's data.

Building on this insight, Shyamsundar created a program that allows researchers to monitor nanoparticle formation using cameras they have on hand. Using the program, they discovered how the nanoparticles formed.
She found out the formation mechanism wasn't the classical one of metal atoms coming together one by one. It was actually clusters of metal atoms coalescing.

This innovation was possible not only because Nivedita is outstandingly smart and a hard worker, but because she is unusually talented in engaging available tools to solve longstanding problems in creative, robust ways that make real impact.
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