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Comment by Dr. Krishna Kumari Challa on May 7, 2025 at 11:59am

A recently-discovered termite terminator is better, more targeted and won't harm humans

Drywood termites, the ones that hide in wooden structures, molt about seven times in their lives. Researchers have found that a chemical preventing them from growing new exoskeletons will also end their infestation of your home.

The chemical, bistrifluron, and its ability to kill about 95% of a termite colony without off-target effects on mammals, are documented in a paper published in the Journal of Economic Entomology.

This chemical is more environmentally friendly than ones traditionally used for drywood termite infestation. It's specific to insects and can't harm humans.

Unlike humans with skeletons located inside their flesh, termites have exoskeletons on the outside that protect them from the elements. The main component of these external skeletons is chitin, which is also found in fungal cell walls, fish scales, and the beaks of squids and octopuses. Chitin also provides mechanical strength for insect exoskeletons, making them suitable as armor as well as sites for muscle attachment.

As termites are getting ready to molt, something they must do in order to grow, they also produce chitin to create the new exoskeleton. Bistrifluron prevents them from doing so.

Once the termites reach a certain stage, they have to molt. They cannot avoid that. With a lethal dose of this chemical, they'll try to shed their old exoskeleton but won't have a new one ready to protect them. 

The researchers observed that bistrifluron initially slows the termites down, reducing their feeding activity. Eventually it prevents them from molting, and they die. This is one of the first studies that looks at the impact of chitin-inhibiting chemicals on drywood termites.

As the termites eat the treated wood, they also spread the chemical to other members of the colony. Full collapse happens in about two months, which is slower than other methods but carries certain advantages in addition to lower toxicity.

Nicholas A Poulos et al, Toxicity and horizontal transfer of chitin synthesis inhibitors in the western drywood termite (Blattodea: Kalotermitidae), Journal of Economic Entomology (2025). DOI: 10.1093/jee/toaf064

Comment by Dr. Krishna Kumari Challa on May 7, 2025 at 11:50am

Why some mammals glow under ultraviolet light

Scientists have been trying to discover exactly why some animals glow under ultraviolet light as photoluminescence in mammal fur is common.

 Rats, along with bandicoots, possums, bats, tree-kangaroos and many other creatures  around the world are photoluminescent; they glow under ultraviolet, violet or blue light.

Scientists' aim 's to identify luminophores (molecules or groups of molecules) contributing to photoluminescence.

The researchers  shaved fur from roadkill and subjected it to high-performance liquid chromatography.

The fur of the  northern long-nosed and northern brown bandicoots photoluminesces strongly, displaying pink, yellow, blue and/or white colors. The researchers wanted to find out whether the luminophores present in bandicoot fur might be common across multiple species.

So they compared the results from the two bandicoots to the northern quoll, the coppery brushtail possum, the Lumholtz's tree-kangaroo, the pale field rat and the platypus—all of which photoluminesce in different ways.

The scientists confirmed metabolites of the amino acid tryptophan and identified derivatives of the chemical compound porphyrin that cause bandicoots, quolls and possums to glow bright pink in UV light.

They   also found a contributing cause of the colour of coppery brushtail possum fur—not photoluminescent, but a strong purple colouration in white light—a match for the molecule Indigo—which is also extracted as a dye from plants.

 Linda M. Reinhold et al, Luminophores in the fur of seven Australian Wet Tropics mammals, PLOS One (2025). DOI: 10.1371/journal.pone.0320432. journals.plos.org/plosone/arti … journal.pone.0320432

Comment by Dr. Krishna Kumari Challa on May 7, 2025 at 9:47am

Tire additives found deposited on fruits and vegetables

A new study has found that tire additives enter into and pass through the food chain. Further research is needed to establish the implications for human health.

Traces of the additives typically used in tire manufacturing have been detected in all of the most common types of fruits and vegetables.  The scientists don't yet know the long-term implications of exposure to these substances for human health. Further research is needed to clarify this point.

The study follows on from two Austrian studies demonstrating that these additives were present in leafy vegetables. 

Researchers  sampled around 100 of the most commonly eaten fruits and vegetables  from major supermarket chains to organic markets and small,  grocery stores.

After rinsing the fruits and vegetables and turning them into workable samples, the scientists tested them for 11 compounds typically found in tire additives. Using consumption data held by the FSVO, they were then able to calculate theoretical daily intake values for these substances.

They found that 31% of the samples contained traces of the compounds, including 6-PPD and 6-PPD-quinone, with no difference according to where the fruits and vegetables came from or whether they were organic.

Previous studies have established that tire additives, especially DPG, 6-PPD and 6-PPD-quinone, are toxic to mammals. This research, which has so far been carried out only on rodents, found that these additives lead to decreased fertility in males and have neurotoxic and neuroinflammatory effects.

Scientists in China are also conducting in-depth research into the subject, analyzing human blood and urine for the presence of these substances.

When tires wear against road surfaces, they release additives such as antioxidants and vulcanizing agents (which give rubber more strength, elasticity and durability). These particles, the toxicity of which is yet to be determined, disperse through the air, settle on the ground, and are transported in runoff water. Humans are exposed to them in two ways: by inhaling them and, as the EPFL-FSVO study shows, by ingesting them in contaminated food.

According to a paper published in 2017, six million metric tons of these additives are released into the environment every year. Our exposure to these additives is similar to that for other micropollutants. 

They're around us constantly, in every part of our environment. What we don't know is whether we need to introduce tighter controls, such as by phasing them out in tire manufacturing in favor of less toxic alternatives.

Scientists  are currently exploring ways in which roads can be decontaminated to prevent tire additives from entering the environment. Several studies have shown that aggressive driving—with hard acceleration and braking—increases tire wear, making it more likely that these particles will transfer into the air, soil and surface water.

 Florian Breider et al, Assessment of tire-derived additives and their metabolites into fruit, root and leafy vegetables and evaluation of dietary intake in Swiss adults, Journal of Hazardous Materials (2025). DOI: 10.1016/j.jhazmat.2025.138432

Comment by Dr. Krishna Kumari Challa on May 6, 2025 at 12:11pm

Experimental peptide treatment could triple survival rates in severe blood loss cases

Researchers  have discovered a promising new therapeutic approach to treating hemorrhagic shock, a life-threatening condition caused by severe blood loss that remains the leading cause of preventable death in trauma cases globally.

The study demonstrated that activating Protein Kinase C epsilon (PKC-ε) significantly improves early survival rates and physiological stability following severe hemorrhage.

The work is published in the journal Scientific Reports.

In a carefully controlled experiment using a porcine model, researchers induced hemorrhagic shock by withdrawing 35% of the animals' total blood volume. Animals treated with a PKC-ε activator peptide just five minutes after the onset of bleeding showed dramatically improved survival—73% of treated subjects survived compared to only 25% of those left untreated.

Additionally, treated animals maintained significantly better cardiovascular stability, including blood pressure, heart rate, and cardiac output, all critical indicators of effective response during severe trauma.

Moreover, detailed analysis of mitochondrial activity revealed enhanced function within the heart tissues of animals receiving the PKC-ε activator. As mitochondria are vital cellular energy producers, these findings suggest that activating PKC-ε helps maintain organ energy levels under stress, potentially protecting tissues against further damage associated with severe blood loss.

The implications of this study are far-reaching. Current therapeutic strategies for severe hemorrhagic shock often involve fluid resuscitation, which can unintentionally exacerbate tissue damage by triggering ischemic-reperfusion injury.

This new approach—administering a PKC-ε activator peptide—has the potential to significantly minimize these detrimental effects, thereby improving survival chances and reducing complications associated with severe trauma.

Maya Simchoni et al, Protein kinase C epsilon activation improves early survival in an acute porcine model of controlled hemorrhage, Scientific Reports (2025). DOI: 10.1038/s41598-025-92310-3

Comment by Dr. Krishna Kumari Challa on May 6, 2025 at 11:51am

Tetracycline antibiotics impair T cell function by targeting mitochondria

A team of international researchers has revealed in unprecedented detail how tetracycline antibiotics impair T cell function by binding mitochondrial ribosomes and inhibiting oxidative metabolism (OXPHOS). The study, reported in Nature Communications, raises mechanistic considerations for antibiotic therapy and the design of new molecules that can better discriminate between pathogen and host.

Antibiotics historically developed to inhibit bacterial protein synthesis cross-react with mitochondrial ribosomes due to shared evolutionary features, impairing translation of key phosphorylation complex subunits in host cells. Indeed, certain antibiotics, such as tetracyclines, have a long history in the treatment of inflammatory conditions, such as rheumatoid arthritis, although large controlled cohort studies are lacking, in part due to the lack of a molecular mechanism.

When you take antibiotics, the effects are not solely restricted to commensal and pathogenic bacteria. Some of your cells take a hit, and there is good evidence in the literature to support reversible inhibition of that mitochondrial translation can be used to treat inflammatory diseases.

The researchers identified specific structural features of mitochondrial ribosomes that could potentially be targeted to develop more selective therapeutics.

"The discrimination between bacterial and human mitochondrial ribosomes represents an important frontier for antibiotic development. By understanding the specific binding domains within the mitoribosome that interact with tigecycline, it will be possible to design next-generation entities with different specificities, whether those affect the host or pathogen.

Qiuya Shao et al, T cell toxicity induced by tigecycline binding to the mitochondrial ribosome, Nature Communications (2025). DOI: 10.1038/s41467-025-59388-9

Comment by Dr. Krishna Kumari Challa on May 6, 2025 at 11:16am

Probing the molecular mechanisms of metastasis

Cells have a mailing system of sorts. They can release tiny molecular balls, called extracellular vesicles (EVs), that contain biological matter or messages and attach to other cells to share whatever they contain.

In cancer, EVs often depart from tumour cells to seed the cancer elsewhere in the body, leading to metastasis. However, how the EVs connected to recipient cells to deliver their payload has remained a mystery—until now. A team of researchers has now revealed the molecular mechanisms underpinning the process for small EVs (sEVs), which they said could have implications for developing better cancer treatments.

The team published their findings in the Journal of Cell Biology.

EVs can serve as biomarkers, since they carry specific proteins and genetic material that can indicate disease progression. Researchers have also started to explore their potential to treat cancers, either by inhibiting their binding to host cells or by encouraging the binding of EVs with therapeutic payloads.

The researchers now focused on understanding the role of integrin heterodimers, which are molecules that help sEVs adhere to the host cell. The same team previously found that sEVs could be sorted into subtypes with different properties, depending on which tetraspanin protein it has. This type of protein is small but critical to EV formation and regulation.

Using this understanding, the researchers sorted and tracked the sEVs with single-molecule resolution.

They examined the sorted subtypes with super-resolution microscopy to find that all subtypes primarily used integrin heterodimers associated with a specific tetraspanin protein known as CD151 and a molecule containing carbohydrates and fats called GM1 to bind to laminin, a protein critical to cellular membranes and heavily involved in cell membrane structure and cell adhesion, among other responsibilities.

Laminin is specifically a glycoprotein, meaning it is a protein with a carbohydrate, or sugar, molecule attached to it. It exists in the extracellular matrix, or the molecular network surrounding cells and supports their signaling and structure.

Quantitative analysis using single-molecule imaging and super-resolution microscopy demonstrated that all EV subtypes derived from four distinct tumor cell lines, irrespective of size, predominantly bind to laminin via CD151-associated integrin heterodimers and GM1, thereby eliciting responses in recipient cells.

EVs bound to laminin significantly more than they bound to fibronectin, which is another protein responsible for cell adhesion in the extracellular matrix.

Two other proteins associated with adhesion in the EVs, talin and kindlin, did not activate the integrin heterodimers. Taken all together, the researchers concluded that GM1 and integrin heterodimers associated with CD151 are key for EV binding. This understanding could help researchers better inhibit or encourage binding as needed in the name of disease treatment.

 Tatsuki Isogai et al, Extracellular vesicles adhere to cells primarily by interactions of integrins and GM1 with laminin, Journal of Cell Biology (2025). DOI: 10.1083/jcb.202404064

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Comment by Dr. Krishna Kumari Challa on May 6, 2025 at 11:05am

Technically, it is currently impossible to accelerate rockets to a speed at which this effect could be seen in a photograph. However, physicists found another solution inspired by art: they used extremely short laser pulses and a high-speed camera to recreate the effect in the laboratory.
They moved a cube and a sphere around the lab and used the high-speed camera to record the laser flashes reflected from different points on these objects at different times.
It is easy to combine images of different parts of a landscape into one large image. What has been done here for the first time is to include the time factor: the object is photographed at many different times. Then the areas illuminated by the laser flash at the moment when the light would have been emitted from that point if the speed of light was only 2 m/s are combined into one still image. This makes the Terrell-Penrose effect visible.
They combined the still images into short video clips of the ultra-fast objects. The result was exactly what they expected.
The demonstration of the Terrell-Penrose effect is not only a scientific success—it is also the result of an extraordinary symbiosis between art and science.

Dominik Hornof et al, A snapshot of relativistic motion: visualizing the Terrell-Penrose effect, Communications Physics (2025). DOI: 10.1038/s42005-025-02003-6

Part 2

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Comment by Dr. Krishna Kumari Challa on May 6, 2025 at 11:02am

Special relativity made visible

When an object moves extremely fast—close to the speed of light—certain basic assumptions that we take for granted no longer apply. This is the central consequence of Albert Einstein's special theory of relativity. The object then has a different length than when it is at rest, and time passes differently for the object than it does in the laboratory. All this has been repeatedly confirmed in experiments.

However, one interesting consequence of relativity has not yet been observed—the so-called Terrell-Penrose effect. In 1959, physicists James Terrell and Roger Penrose (Nobel laureate in 2020) independently concluded that fast-moving objects should appear rotated. 

Now, a collaboration study has succeeded for the first time in reproducing the effect using laser pulses and precision cameras—at an effective speed of light of 2 meters per second. The research is published in the journal Communications Physics.

Suppose a rocket whizzes past us at 90% of the speed of light. For us, it no longer has the same length as before it took off, but is 2.3 times shorter. This is the relativistic length contraction, also known as the Lorentz contraction.

However, this contraction cannot be photographed. If you want to take a picture of the rocket as it flew past, you will have to take into account that the light from different points take different lengths of time to reach the camera. 

The light coming from different parts of the object and arriving at the lens or our eye at the same time is not emitted at the same time—and this results in complicated optical effects.

Let's imagine that the super-fast object is a cube. Then the side facing away from us is further away than the side facing towards us. If two photons reach our eye at the same time, one from the front corner of the cube and one from the back corner, the photon from the back corner has traveled further. So it must have been emitted at an earlier time. And at that time, the cube was not at the same position as when the light was emitted from the front corner. This makes it look to us as if the cube has been rotated.

This is a combination of relativistic length contraction and the different travel times of light from different points. Together, this leads to an apparent rotation, as predicted by Terrell and Penrose.

Of course, this is irrelevant in everyday life, even when photographing an extremely fast car. Even the fastest Formula One car will only move a tiny fraction of the distance in the time difference between the light emitted by the side of the car facing away from us and the side facing towards us. But with a rocket traveling close to the speed of light, this effect would be clearly visible.

Part 1

Comment by Dr. Krishna Kumari Challa on May 5, 2025 at 9:33am

Home washing machines fail to remove important pathogens from textiles

Health care workers who wash their uniforms at home may be unknowingly contributing to the spread of antibiotic-resistant infections in hospitals, according to a new study published in PLOS One.

Hospital-acquired infections are a major public health concern, in part because they frequently involve antibiotic-resistant bacteria. Many nurses and health care workers clean their uniforms at home in standard washing machines, but some studies have found that bacteria can be transmitted through clothing, raising the question of whether these machines can sufficiently prevent the spread of dangerous microbes.

In the new study, researchers evaluated whether six models of home washing machine successfully decontaminated health care worker uniforms, by washing contaminated fabric swatches in hot water, using a rapid or normal cycle. Half of the machines did not disinfect the clothing during a rapid cycle, while one-third failed to clean sufficiently during the standard cycle.

The team also sampled biofilms from inside 12 washing machines. DNA sequencing revealed the presence of potentially pathogenic bacteria and antibiotic resistance genes. Investigations also showed that bacteria can develop resistance to domestic detergent, which also increases their resistance to certain antibiotics.

This research shows that domestic washing machines often fail to disinfect textiles, allowing antibiotic-resistant bacteria to survive. If we're serious about the transmission of infectious disease via textiles and tackling antimicrobial resistance, we must rethink how we launder what we wear.  

Caroline Cayrou et al, Domestic laundering of healthcare textiles: Disinfection efficacy and risks of antibiotic resistance transmission, PLOS One (2025). DOI: 10.1371/journal.pone.0321467. journals.plos.org/plosone/arti … journal.pone.0321467

Comment by Dr. Krishna Kumari Challa on May 3, 2025 at 6:59am

In extreme conditions, heat does not flow between materials—it bounces off

A new study published in Nature Communications shows, for the first time, how heat moves—or rather, doesn't—between materials in a high-energy-density plasma state.

The work is expected to provide a better understanding of inertial confinement fusion experiments, which aim to reliably achieve fusion ignition on Earth using lasers. How heat flows between a hot plasma and a material's surface is also important in other technologies, including semiconductor etching and vehicles that fly at hypersonic speeds.

High-energy-density plasmas are produced only at extreme pressures and temperatures. The study shows that interfacial thermal resistance, a phenomenon known to impede heat transfer in less extreme conditions, also prevents heat flow between different materials in a dense, super-hot plasma state.

Researchers focused on how heat moves between metal and plastic heated to extreme temperatures and pressures. 

In their experiment, the tungsten wire was heated to about 180,000 degrees Fahrenheit while its plastic coating remained relatively cool at "only" 20,000 degrees Fahrenheit. Using a series of laser shots with progressively delayed timing, the researchers were able to see if the heat was moving between the tungsten and plastic.

When they looked at the data, they were totally shocked because the heat was not flowing between these materials. It was getting stuck at the interface between the materials. 

The reason was interfacial thermal resistance. The electrons in the hotter material arrive at the interface between the materials carrying thermal energy but then scatter off and move back into the hotter material.

Cameron H. Allen et al, Measurement of interfacial thermal resistance in high-energy-density matter, Nature Communications (2025). DOI: 10.1038/s41467-025-56051-1

https://vimeo.com/1065285809

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