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Comment by Dr. Krishna Kumari Challa on July 24, 2025 at 6:29am

Scientists use dental floss to deliver vaccines without needles

Flossing your teeth at least once a day is an essential part of any oral health routine. But it might also one day protect other parts of the body as scientists have created a novel, needle-free vaccine approach using a specialized type of floss.

In a study published in Nature Biomedical Engineering, researchers demonstrated that when floss laced with vaccine  components, such as proteins and inactive viruses, was applied along the gum lines of mice, it triggered an immune response.

This method of vaccine delivery is effective because the areas of gum between the teeth are highly permeable, allowing them to absorb vaccine molecules easily.

In the experiment, researchers flossed 50 mice every two weeks for 28 days, which wasn't an easy task. To floss each mouse, one person had to gently pull their jaw down with the metal ring from a keychain while another did the flossing.

Four weeks after the final vaccine dose, the mice were exposed to a lethal strain of flu.

All rodents that received the floss-based vaccine survived while the unvaccinated animals died. Additionally, the mice that had been flossed had a more widespread immune response throughout their bodies. Flu antibodies were detected in their feces, saliva and even in their bone marrow.

Finding antibodies in the bone marrow suggests the mice's bodies had established a long-term immune response. The researchers also saw an increase in T Cells (a type of immune cell that fights off infections) in the mice's lungs and spleen.

Next, the researchers wanted to see whether flossing would be a viable approach for humans. So they asked 27 healthy volunteers to floss with dental picks coated with food dye. On average, the dye reached the gums about 60% of the time.

The mouth and nose are the primary entry points for many viruses, making the oral cavity an ideal site for vaccine delivery. However, scientists have faced significant hurdles in developing needle-free vaccine alternatives for these areas due to the body's tough defenses against foreign invaders. A floss-based approach could bypass these challenges, offering a promising new method.

 Rohan S. J. Ingrole et al, Floss-based vaccination targets the gingival sulcus for mucosal and systemic immunization, Nature Biomedical Engineering (2025). DOI: 10.1038/s41551-025-01451-3

Comment by Dr. Krishna Kumari Challa on July 23, 2025 at 2:15pm

Engineered bacteria pave the way for vegan cheese and yogurt

Bacteria are set to transform the future of dairy-free milk products. Scientists have successfully engineered E. coli to produce key milk proteins essential for cheese and yogurt production, without using any animal-derived ingredients. This paves the way for plant-based dairy alternatives that mimic traditional dairy at a molecular level but are sustainable and cruelty-free.

A recent study published in Trends in Biotechnology reported two methods for producing casein (a milk protein) that are nutritionally and functionally similar to bovine casein.

Casein is a highly sought-after component in both infant and adult diets, as it is digestible, of high quality, and provides several essential amino acids our body needs.

The food and pharmaceutical industries have utilized microorganisms as cell factories for the large-scale production of biomolecules, dietary supplements, and enzymes for quite some time. Scientists were curious to see if the same approach could be used for recombinant casein proteins, produced through genetic engineering in microbial cell factories. However, these techniques often fail to replicate a key factor that imparts casein its unique properties—phosphorylation, a biological process where a phosphate group is added to a protein.

Phosphorylation of serine residues (amino acid components) is critical for casein's ability to bind calcium, which makes milk stable and provides it with nutritional properties. Calcium binding also ensures the formation of nanoscale protein structures called casein micelles, which act as delivery agents for bioavailable calcium and phosphate.

To overcome this issue, the researchers adopted two main strategies. First, they engineered bacteria to co-express three Bacillus subtilis protein kinases, which are enzymes that catalyze the addition of phosphate groups to proteins. Second, they designed a phosphomimetic version of αs1-casein, in which serine residues normally phosphorylated in the naturally occurring protein were replaced with aspartic acid to mimic the negative charge and functional effects of phosphorylation.

The team carried out structural analysis, calcium-binding tests, and simulated gastrointestinal digestion of the derived αs1-casein. The results indicated that both the phosphorylated and phosphomimetic caseins of bacterial origin had a high calcium-binding capacity, and their digestibility and structure were comparable to that of cattle-derived casein.

The researchers highlighted that while kinase-mediated phosphorylation provides a route for closely mimicking native casein, phosphomimetic casein provides a simpler path for producing functionally similar proteins. 

 Suvasini Balasubramanian et al, Production of phosphorylated and functional αs1-casein in Escherichia coli, Trends in Biotechnology (2025). DOI: 10.1016/j.tibtech.2025.05.015

Comment by Dr. Krishna Kumari Challa on July 23, 2025 at 2:10pm

Quantum internet moves closer as researchers teleport light-based information

Quantum teleportation is a fascinating process that involves transferring a particle's quantum state to another distant location, without moving or detecting the particle itself. This process could be central to the realization of a so-called "quantum internet," a version of the internet that enables the safe and instant transmission of quantum information between devices within the same network.

Quantum teleportation is far from a recent idea, as it was experimentally realized several times in the past. Nonetheless, most previous demonstrations utilized frequency conversion rather than natively operating in the telecom band.

Researchers recently demonstrated the teleportation of a telecom-wavelength photonic qubit (i.e., a quantum bit encoded in light at the same wavelengths supporting current communications) to a telecom quantum memory. Their paper, published in Physical Review Letters, could open new possibilities for the realization of scalable quantum networks and thus potentially a quantum internet.

 Yu-Yang An et al, Quantum Teleportation from Telecom Photons to Erbium-Ion Ensembles, Physical Review Letters (2025). DOI: 10.1103/3wh8-2gh1.

Comment by Dr. Krishna Kumari Challa on July 19, 2025 at 9:41am

The researchers also investigated how sleepy a participant felt when they woke up. While participants felt the sleepiest when awoken from REM sleep, the impact of the slow waves in non-REM sleep stages is quite intriguing.

They found a new aspect in which slow waves can present very distinct and opposite behaviors. Some slow waves are actually acting like arousal elements—they are part of the 'wake up!' signal. The more these waves occur just before awakening, the more alert you tend to feel upon awakening. While the other slow waves—whether they are present before waking up or persisting after—are the reason we sometimes feel so sleepy in the first moments of the day.
These findings can be used for future research into sleep disorders, such as insomnia or conditions involving incomplete awakenings.

Aurélie M. Stephan et al, Cortical activity upon awakening from sleep reveals consistent spatio-temporal gradients across sleep stages in human EEG, Current Biology (2025). DOI: 10.1016/j.cub.2025.06.064

Part 2

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Comment by Dr. Krishna Kumari Challa on July 19, 2025 at 9:37am

Scientists discover a signature 'wave' of activity as the brain awakens from sleep

Each morning, your brain embarks on a remarkable series of events: it transitions from being asleep, potentially in an alternate reality, to waking up. Within a short time, you regain waking consciousness, reorient yourself and reconnect with your surroundings, becoming ready to interact with the world again. But how does your brain accomplish this transition so safely and efficiently?

To better understand the awakening brain, researchers  analyzed over 1,000 awakenings using high-density EEG recordings on a second-by-second basis.

The study, published in Current Biology, reveals that the brain doesn't wake up all at once. Instead, it orchestrates a precise sequence of activation.

The researchers worked with high-density EEG data, which offers information about the time and location of brain activity. When looking at the activity progression throughout the awakening brain, they observed a clear sequence: it starts in central and frontal brain regions and gradually spreads toward the back of the brain.

This progression likely reflects how signals from subcortical arousal centers (deeper in the brain) reach the cortex, with shorter paths to frontal areas and longer ones toward regions further back.

To better understand how the brain navigates waking up at any moment, the researchers specifically studied awakening patterns in two stages: REM sleep, commonly associated with vivid dreams, and non-REM sleep, also known as deep sleep.

When participants awoke from non-REM sleep, their brain activity first showed a brief surge in slower sleep-like waves immediately followed by faster activity related to wakefulness. When participants awoke from REM sleep, the slower waves were skipped, leading to a more direct boost in faster brain activity.

"The brain responds differently to arousing signals depending on the stage it's in", the researchers say. "In non-REM sleep, neurons that connect arousal centers to the cortex alternate between states of activity and silence—a dynamic known as 'bistability.'

"As a result of this bistability, any arousing stimulus first triggers a slow wave, before transitioning to faster activity. In contrast, REM sleep does not have this bistable pattern, so the cortex immediately responds with the fast, wake-like, activity."

Part 1

Comment by Dr. Krishna Kumari Challa on July 19, 2025 at 9:28am

To directly test whether MER11 sequences can control gene expression, the team used a technique called lentiMPRA (lentiviral massively parallel reporter assay). This method allows thousands of DNA sequences to be tested at once by inserting them into cells and measuring how much each one boosts gene activity.

The researchers applied this method to nearly 7,000 MER11 sequences from humans and other primates, and measured their effects in human stem cells and early-stage neural cells.

The results showed that MER11_G4 (the youngest subfamily) exhibited a strong ability to activate gene expression. It also had a distinct set of regulatory "motifs," which are short stretches of DNA that serve as docking sites for transcription factors, the proteins that control when genes are turned on. These motifs can dramatically influence how genes respond to developmental signals or environmental cues.

Further analysis revealed that the MER11_G4 sequences in humans, chimpanzees, and macaques had each accumulated slightly different changes over time. In humans and chimpanzees, some sequences gained mutations that could increase their regulatory potential in human stem cells.

Young MER11_G4 binds to a distinct set of transcription factors, indicating that this group gained different regulatory functions through sequence changes and contributes to speciation
The study offers a model for understanding how "junk" DNA can evolve into regulatory elements with important biological roles. By tracing the evolution of these sequences and directly testing their function, the researchers have demonstrated how ancient viral DNA has been co-opted into shaping gene activity in primates.

Xun Chen et al, A phylogenetic approach uncovers cryptic endogenous retrovirus subfamilies in the primate lineage, Science Advances (2025). DOI: 10.1126/sciadv.ads9164. www.science.org/doi/10.1126/sciadv.ads9164

Part 2

Comment by Dr. Krishna Kumari Challa on July 19, 2025 at 9:27am

Study reveals hidden regulatory roles of 'junk' DNA

A new international study suggests that ancient viral DNA embedded in our genome, which were long dismissed as genetic "junk," may actually play powerful roles in regulating gene expression. Focusing on a family of sequences called MER11, researchers have shown that these elements have evolved to influence how genes turn on and off, particularly in early human development.

The findings are published in the journal Science Advances.

Transposable elements (TEs) are repetitive DNA sequences in the genome that originated from ancient viruses. Over millions of years, they spread throughout the genome via copy-and-paste mechanisms.

Today, TEs make up nearly half of the human genome. While they were once thought to serve no useful function, recent research has found that some of them act like "genetic switches," controlling the activity of nearby genes in specific cell types.

However, because TEs are highly repetitive and often nearly identical in sequence, they can be difficult to study. In particular, younger TE families like MER11 have been poorly categorized in existing genomic databases, limiting our ability to understand their role.

To overcome this, the researchers developed a new method for classifying TEs. Instead of using standard annotation tools, they grouped MER11 sequences based on their evolutionary relationships and how well they were conserved in the primate genomes.

This new approach allowed them to divide MER11A/B/C into four distinct subfamilies, namely, MER11_G1 through G4, ranging from oldest to youngest.

This new classification revealed previously hidden patterns of gene regulatory potential. The researchers compared the new MER11 subfamilies to various epigenetic markers, which are chemical tags on DNA and associated proteins that influence gene activity. This showed that this new classification aligned more closely with actual regulatory function compared with previous methods.

Part 1

Comment by Dr. Krishna Kumari Challa on July 19, 2025 at 7:42am

Why do we need sleep? Researchers find the answer may lie in mitochondria

Sleep may not just be rest for the mind—it may be essential maintenance for the body's power supply. A new study by University of Oxford researchers, published in Nature, reveals that the pressure to sleep arises from a build-up of electrical stress in the tiny energy generators inside brain cells.

The discovery offers a physical explanation for the biological drive to sleep and could reshape how scientists think about sleep, aging, and neurological disease.

The team found that sleep is triggered by the brain's response to a subtle form of energy imbalance. The key lies in mitochondria—microscopic structures inside cells that use oxygen to convert food into energy.

When the mitochondria of certain sleep-regulating brain cells (studied in fruit flies) become overcharged, they start to leak electrons, producing potentially damaging byproducts known as reactive oxygen species. This leak appears to act as a warning signal that pushes the brain into sleep, restoring equilibrium before damage spreads more widely.

The researchers found that specialized neurons act like circuit breakers—measuring this mitochondrial electron leak and triggering sleep when a threshold is crossed. By manipulating the energy handling in these cells—either increasing or decreasing electron flow—the scientists could directly control how much the flies slept.

Even replacing electrons with energy from light (using proteins borrowed from microorganisms) had the same effect: more energy, more leak, more sleep.

In certain sleep-regulating neurons, they discovered that mitochondria—the cell's energy producers—leak electrons when there is an oversupply. When the leak becomes too large, these cells act like circuit breakers, tripping the system into sleep to prevent overload.

The findings help explain well-known links between metabolism, sleep, and lifespan. Smaller animals, which consume more oxygen per gram of body weight, tend to sleep more and live shorter lives. Humans with mitochondrial diseases often experience debilitating fatigue even without exertion, now potentially explained by the same mechanism.

This research answers one of biology's big mysteries. "Why do we need sleep? The answer appears to be written into the very way our cells convert oxygen into energy."

Raffaele Sarnataro et al, Mitochondrial origins of the pressure to sleep, Nature (2025). DOI: 10.1038/s41586-025-09261-y

Comment by Dr. Krishna Kumari Challa on July 19, 2025 at 7:31am

Vision problems emerge as astronauts spend months in orbit

When astronauts began spending six months and more aboard the International Space Station, they started to notice changes in their vision. For example, many found that, as their mission progressed, they needed stronger reading glasses. Researchers studying this phenomenon identified swelling in the optic disk, which is where the optic nerve enters the retina, and flattening of the eye shape. These symptoms became known as Space-Associated Neuro-Ocular Syndrome (SANS).

Microgravity causes a person's blood and cerebrospinal fluid to shift toward the head and studies have suggested that these fluid shifts may be an underlying cause of SANS.

A current investigation, Thigh Cuff, examines whether tight leg cuffs change the way fluid moves around inside the body, especially around the eyes and in the heart and blood vessels.

If so, the cuffs could serve as a countermeasure against the problems associated with fluid shifts, including SANS. A simple and easy-to-use tool to counter the headward shift of body fluids could help protect astronauts on future missions to the moon and Mars. The cuffs also could treat conditions on Earth that cause fluid to build up in the head or upper body, such as long-term bed rest and certain diseases.

These and other studies ultimately could help researchers prevent, diagnose, and treat vision impairment in crew members and people on Earth.

Source: NASA

Comment by Dr. Krishna Kumari Challa on July 19, 2025 at 7:17am

Don't feed the animals: Researchers warn of risks tied to wildlife interactions

A study by  scientists  offers new warnings on the dangers of human interactions with wildlife.

The researchers study endangered Asian elephants and has previously reported on their shrinking habitats, a downturn that has resulted in territorial conflicts between people and elephants.

The new study now provides fresh evidence in the journal Ecological Solutions and Evidence on the serious consequences of humans supplying food to wild animals. The report indicates that such provisioning can lead wildlife to become habituated to people, causing the animals to become bolder and more prone to causing problems. Even for those who live in areas without native elephant populations, the new study provides cautionary information about interactions with any wildlife species living among us.

In Sri Lanka, they studied 18 years of elephant-tourist interactions at Udawalawe National Park. They found that the elephants congregating near tourists at the park's southern boundary have developed "begging" behaviour and have become habituated to sugary foods, sometimes breaking through fences to continue being fed.

As a result of elephants being drawn to the fence, several people have been killed or injured, and at least three elephants have been killed, while others have ingested plastic food bags and other contaminants. Such close human-wildlife encounters, including tourists feeding animals from sightseeing vehicles, also increases the risk of disease transmission to animals.

In India's Sigur region, study co-authors observed feeding interactions with 11 male Asian elephants, four of whom died from suspected human causes. One elephant was successfully rehabilitated and returned to natural foraging behaviour.

Many people, especially foreign tourists, think Asian elephants are tame and docile, like domestic pets, the researchers say, that they don't realize these are formidable wild animals and try to get too close in order to take photographs or selfies, which can end badly for both parties.

Of the 800 to 1,200 elephants estimated to live in Udawalawe National Park, the study found that 66 male elephants, or 9–15% of the local male population of Asian elephants, were observed begging for food. Some elephants, including a popular male named Rambo, became local celebrities as they solicited food from tourists over several years.

"Food-conditioned animals can become dangerous, resulting in the injury and death of wildlife, people or both," the researchers note in their paper. "These negative impacts counteract potential benefits."

Since wild elephant feeding cannot be adequately regulated as an ongoing activity, the authors of the study recommend that feeding bans should be strictly enforced.

Such interactions  can change animals' movement patterns and possibly force them to lose knowledge of natural food sources if they become too dependent on handouts.

With rare exceptions, people should avoid feeding wild animals, the researchers urge, and encourages people to engage in responsible tourism.

Don't Feed The Elephant: A Critical Examination of Food-Provisioning Wild Elephants, Ecological Solutions and Evidence (2025). DOI: 10.1002/2688-8319.70060

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