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Comment by Dr. Krishna Kumari Challa 1 hour ago

'Don't use them': Tanning beds triple skin cancer risk, study finds

Tanning bed use is associated with nearly a threefold increase in melanoma risk, with users developing more DNA mutations in skin cells, particularly melanocytes. Melanomas in tanning bed users often appear on body areas usually shielded from sunlight. Over 80% of common melanomas are linked to ultraviolet radiation, including that from tanning beds.

Pedram Gerami et al, Molecular effects of indoor tanning, Science Advances (2025). DOI: 10.1126/sciadv.ady4878. www.science.org/doi/10.1126/sciadv.ady4878

Comment by Dr. Krishna Kumari Challa 1 hour ago

New sprayable powder forms instant gel barrier to stop severe bleeding in seconds

A sprayable powder hemostatic agent rapidly forms a hydrogel barrier within one second upon contact with blood, effectively stopping severe bleeding, including from deep or irregular wounds. Composed of biocompatible natural materials, it demonstrates high absorption (725%), strong adhesion (>40 kPa), low hemolysis (<3%), high cell viability (>99%), and antibacterial properties (99.9%).

Youngju Son et al, An Ionic Gelation Powder for Ultrafast Hemostasis and Accelerated Wound Healing, Advanced Functional Materials (2025). DOI: 10.1002/adfm.202523910

Comment by Dr. Krishna Kumari Challa 1 hour ago

Study shows tooth loss, not low-protein intake, drives memory decline in aging mice
Tooth loss in aging mice leads to significant memory decline and increased markers of brain cell death, independent of dietary protein intake. Reduced chewing, rather than low-protein diet, promotes inflammation and neuronal loss in hippocampal regions critical for memory, highlighting a direct link between oral health and cognitive function.

Tooth loss doesn't just make eating harder, it may also make thinking more challenging. A new study shows that aging mice missing their molars experience measurable cognitive decline, even when their nutrition remains perfectly intact.

The study examined whether tooth loss itself, independent of nutritional deficiency such as a low-protein diet, can cause cognitive decline in male mice.

To explore how chewing ability and nutrition jointly influence the brain, the research team used aging-prone male mice and assigned them to one of four conditions: a normal-protein diet with no tooth extraction, a low-protein diet with no extraction, molar extraction with a normal-protein diet, and molar extraction with a low-protein diet.

After six months, the mice underwent behavioral tests and detailed analyses of their brain tissue for markers of inflammation, neuronal loss, and cell death–related gene expression.

The results were striking: mice that lost their molars showed significant memory decline even though they received the same diet as the control groups.

This suggests that reduced masticatory stimulation, not dietary protein intake, contributes to cognitive deterioration. It is surprising that a peripheral event in the mouth can so profoundly affect the central nervous system.

Brain tissue analysis supported these behavioral findings. The results showed no interaction effect between tooth loss and low-protein diet on the levels of the Bax/Bcl-2 mRNA ratio, a marker representing cell death versus survival.

Instead, tooth loss alone significantly increased this ratio, indicating a shift toward pro-apoptotic, or cell death–promoting, activity in the brain. Losing teeth caused inflammation and cell loss in the CA1 and dentate gyrus regions of the hippocampus—areas essential for memory formation and storage.

Meanwhile, the effects of a low-protein diet were limited to the CA3 region, which plays a role in pattern completion. These findings suggest that a reduction in chewing induces pro–cell death pathways in the brain.

This study adds to growing evidence that oral health is deeply connected to brain health, and that protecting one's chewing ability may be a simple but powerful strategy for preserving cognitive function later in life.

Rie Hatakeyama et al, Tooth loss induces cognitive decline independent of low-protein diet intake in male mice, Archives of Oral Biology (2025). DOI: 10.1016/j.archoralbio.2025.106421

Comment by Dr. Krishna Kumari Challa 1 hour ago

With every extinction, we lose not just a species but a treasure trove of knowledge

Extinction results in the irreversible loss of unique scientific knowledge, cultural traditions, and spiritual connections associated with each species. Current extinction rates, driven mainly by human activities, far exceed natural background levels, threatening up to 1 million species this century. These losses diminish biodiversity, erode cultural and spiritual heritage, and reduce opportunities for future discoveries.

Comment by Dr. Krishna Kumari Challa 1 hour ago

The gut bacteria that put the brakes on weight gain in mice

The gut bacterium Turicibacter reduces weight gain and improves metabolic health in mice on a high-fat diet by producing fatty molecules that lower ceramide levels. Obese individuals tend to have less Turicibacter, suggesting a potential role in human weight regulation. Turicibacter’s effects depend on dietary fat, indicating a feedback loop between diet and gut microbiota.

The gut microbiome is intimately linked to human health and weight. Differences in the gut microbiome—the bacteria and fungi in the gut—are associated with obesity and weight gain, raising the possibility that changing the microbiome could improve health. But any given person's gut contains hundreds of different microbial species, making it difficult to tell which species could help.

Now, new research has identified a specific type of gut bacteria, called Turicibacter, that improves metabolic health and reduces weight gain in mice on a high-fat diet.

People with obesity tend to have less Turicibacter, suggesting that the microbe may promote healthy weight in humans as well. The results could lead to new ways to control weight by adjusting gut bacteria.

The results are published in Cell Metabolism.

The researchers found that a rod-shaped bacterium called Turicibacter could single-handedly reduce blood sugar, levels of fat in the blood, and weight gain for mice on a high-fat diet.

Turicibacter appears to promote metabolic health by producing fatty molecules that are absorbed by the small intestine. When the researchers added purified Turibactor fats to a high-fat diet, they had the same weight-controlling effects as Turicibacter itself.

They don't yet know which fatty molecules are the important part—the bacterium produces thousands of different fats, in what Klag describes as a "lipid soup"—but they hope to narrow down on the most important molecules in future work for potential therapeutic use.

Turicibacter appears to improve metabolic health by affecting how the host produces a fatty molecule called ceramides, the researchers found.

 The fats produced by Turicibacter are able to keep ceramide levels low, even for mice on a high-fat diet.

Turicibacter levels are themselves affected by how much fat the host eats, the researchers discovered. The bacterium won't grow if there's too much fat in its environment, so mice fed a high-fat diet will lose Turicibacter from their gut microbiome unless their diet is regularly supplemented with the microbe.

The results point to a complex feedback loop, in which a fatty diet inhibits Turicibacter and fats produced by Turicibacter improve how the host responds to dietary fats.

Kendra Klag et al, Dietary fat disrupts a commensal-host lipid network that promotes metabolic health, Cell Metabolism (2025). DOI: 10.1016/j.cmet.2025.10.007

Comment by Dr. Krishna Kumari Challa 1 hour ago

How to make clear ice at home

The simplest way to have a go at directional freezing at home is to use an insulated container—you can use a really small cooler (that is, an "esky"), an insulated mug or even a commercially available insulated ice cube tray designed for making clear ice at home.

Fill the insulated container with water and place it in the freezer, then check on it periodically.

Once all the impurities and air bubbles are concentrated in a single cloudy area at the bottom, you can either pour away this water before it's fully frozen through, or let the block freeze solid and then cut off the cloudy portion with a large serrated knife, then cut the ice into cubes for your drinks.

If using a commercial clear ice tray, it will likely come with instructions on how to get rid of the cloudy portion so you can enjoy the sparkling clear ice.

How do I make clear ice at home? A food scientist shares easy tips

Author: Paulomi (Polly) Burey

Professor in Food Science, University of Southern Queensland

Part 3

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Comment by Dr. Krishna Kumari Challa 1 hour ago

Myths about clear ice that don't work

You might think that to get clear ice, you simply need to start out with really clean water. However, a recent study found this isn't the case.

Using boiling water: Starting out with boiling water does mean the water will have less dissolved gases in it, but boiling doesn't remove all impurities. It also doesn't control the freezing process, so the ice will still become cloudy.

Using distilled water: While distilling water removes more impurities than boiling, distilled water still freezes from the outside in, concentrating any remaining impurities or air bubbles in the center, again resulting in cloudy ice.

Using filtered or tap water: Filtering the water or using tap water also doesn't stop the impurities from concentrating during the conventional freezing process.

What actually works

As it turns out, it's not the water quality that guarantees clear ice. It's all about how you freeze it. The main technique for successfully making clear ice is called "directional freezing."

Directional freezing is simply the process of forcing water to freeze in a single direction instead of from all sides at once, like it does in a regular ice cube tray.

This way, the impurities and air will be forced to the opposite side from where the freezing starts, leaving the ice clear except for a small cloudy section.

In practice, this means insulating the sides of the ice container so that the water freezes in one direction, typically from the top down. This is because heat transfer and phase transition from liquid to solid happens faster through the exposed top than the insulated sides.

Part 2

Comment by Dr. Krishna Kumari Challa 2 hours ago

How do I make clear ice at home? A food scientist shares easy tips

Clear ice forms when water freezes in a single direction, pushing air and impurities to one end, unlike typical home freezing that traps them throughout the cube and causes cloudiness. Using an insulated container to promote directional freezing produces clear ice, while water quality or boiling alone does not prevent cloudiness. Clear ice is denser, melts slower, and resists imparting flavors.

Clear ice is actually made from regular water—what's different is the freezing process.

With a little help from science, you can make clear ice at home, and it's not even that tricky. However, there are quite a few hacks on the internet that won't work. Let's dive into the physics and chemistry involved.

Why ice goes cloudy

Homemade ice is often cloudy because it has a myriad of tiny bubbles and other impurities. In a typical ice cube tray, as freezing begins and ice starts to form inward from all directions, it traps whatever is floating in the water: mostly air bubbles, dissolved minerals and gases.

These get pushed toward the center of the ice as freezing progresses and end up caught in the middle of the cube with nowhere else to go.

That's why when making ice the usual way—just pouring water into a vessel and putting in the freezer—it will always end up looking somewhat cloudy. Light scatters as it hits the finished ice cube, colliding with the concentrated core of trapped gases and minerals. This creates the cloudy appearance.

The point of clear ice

As well as looking nice, clear ice is denser and melts slower because it doesn't have those bubbles and impurities. This also means that it dilutes drinks more slowly than regular, cloudy ice.

Because it doesn't have impurities, the clear ice should also be free from any inadvertent flavors that could contaminate your drink.

Additionally, because it's less likely to crumble, clear ice can be easily cut and formed into different shapes to further dress up your cocktail.

If you've tried looking up how to make clear ice before, you've likely seen several suggestions. These include using distilled, boiled or filtered water, and a process called directional freezing. Here's the science on what works and what doesn't.

Part 1

Comment by Dr. Krishna Kumari Challa 2 hours ago

they gathered new valuable observations that could explain in greater detail known differences between the brain functions of humans and other primates. Notably, the researchers also identified transcription factors that modulate the development of the human brain but not of macaques, while also pinpointing types of cells in human tissues that are known to be affected in the brains of patients with specific disorders.

Jiyao Zhang et al, Single-cell spatiotemporal transcriptomic and chromatin accessibility profiling in developing postnatal human and macaque prefrontal cortex, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02150-7

Part 2

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"Our discoveries shed light on human-specific regulatory programs extending postnatal cortical maturation through coordinated neuronal and glial development, with implications for cognition and neurodevelopmental disorders," wrote the team.

Comment by Dr. Krishna Kumari Challa 2 hours ago

Why the human brain matures slower than its primate relatives

The human brain is a fascinating and complex organ that supports numerous sophisticated behaviors and abilities that are observed in no other animal species. For centuries, scientists have been trying to understand what is so unique about the human brain and how it develops over the human lifespan.

Researchers have recently set out to study both the human and macaque brain, comparing their development over time using various genetic and molecular analysis tools. Their paper, published in Nature Neuroscience, highlights some key differences between the two species, with the human pre-frontal cortex (PFC) developing slower than the macaque PFC.

The researchers collected several samples of brain tissue that was surgically removed from the PFC of macaques and humans at different stages after birth. The human subjects were children with epilepsy who were undergoing surgical procedures as part of their treatment plan.

The researchers analyzed the expression of genes in single cells taken from the tissues they collected, as well as chromatin accessibility (i.e., how open DNA is within individual cells). They also mapped the expression of genes across the entire brain tissues, using a technique known as spatial transcriptomics, and looked at the types of cells that were present.

"Integrative analyses outlined species-specific dynamic trajectories of different cell types, highlighting key windows and gene regulatory networks for processes such as synaptogenesis, synaptic pruning and gliogenesis," wrote the authors in their paper.

The researchers' analyses revealed that the human PFC takes longer to develop than that of macaques. They also observed that glial progenitors (i.e., stem-like cells that later divide and develop into specific types of glial cells) proliferate more in humans.
"We identified regulatory correlates of the prolonged development of human PFC relative to macaques," wrote the researchers. "Glial progenitors showed higher proliferation capability in humans compared to macaques, associated with distinct gene expression profiles. Furthermore, we uncovered cell types and lineages most susceptible to neurodevelopmental and neuropsychiatric disorders, focusing on transcription factors with human-specific expression features."

Part 1

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