Comment

Comment by Dr. Krishna Kumari Challa 7 minutes ago

Study provides first evidence that plastic nanoparticles can accumulate in the edible parts of vegetables

Plastic pollution represents a global environmental challenge, and once in the environment, plastic can fragment into smaller and smaller pieces.

A new study shows for the first time that some of the tiniest particles found in the environment can be absorbed into the edible sections of crops during the growing process.

The research used radishes to demonstrate, for the first time, that nanoplastics—some measuring as little as one millionth of a centimeter in diameter—can enter the roots, before spreading and accumulating into the edible parts of the plant.

The researchers say the findings reveal another potential pathway for humans and animals to unintentionally consume nanoplastics and other particles and fibers that are increasingly present in the environment.

It also underscores the need for further research to investigate what is an emerging food safety issue, and the precise impacts it could have on environmental and human health.

This study provides clear evidence that particles in the environment can accumulate not only in seafood but also in vegetables. This work forms part of our growing understanding on accumulation, and the potentially harmful effects of micro- and nanoparticles on human health.

Nathaniel J. Clark et al, Determining the accumulation potential of nanoplastics in crops: An investigation of 14C-labelled polystyrene nanoplastic into radishes, Environmental Research (2025). DOI: 10.1016/j.envres.2025.122687

Comment by Dr. Krishna Kumari Challa 15 minutes ago

A new explanation for Siberia's giant exploding craters

Scientists may be a step closer to solving the mystery of Siberia's giant exploding craters. First spotted in the Yamal and Gydan peninsulas of Western Siberia in 2012, these massive holes, known as giant gas emission craters (GECs) can be up to 164 feet deep. They seem to appear randomly in the permafrost and are formed when powerful explosions blast soil and ice hundreds of feet into the air.

For more than a decade, researchers have been coming up with theories about the origin of these craters, ranging from meteor impacts to gas explosions. However, none of these have been able to explain why the craters are only found in this specific area and not in the permafrost elsewhere in the Arctic.

Now, research published in the journal Science of the Total Environment proposes a new and more complete explanation that links the craters to specific factors unique to the two peninsulas, the vast gas reserves in this region and the effects of climate change.

"We propose that the formation of GECs is linked to the specific conditions in the area, including abundant natural gas generation and seepage and the overall limited thickness of the continuous permafrost," wrote the researchers in their paper.

According to their model, GECs form when gas and heat rise from deep underground. The heat melts the permafrost seal (a layer of permanently frozen ground that acts as a lid), making it thinner. Meanwhile, the gas builds up underneath it, and with nowhere to go, the pressure rises. As the climate warms, the permafrost thaws even more, making the lid thinner. Eventually, pressure becomes too great and causes an explosive collapse that creates a large crater.

 Helge Hellevang et al, Formation of giant Siberian gas emission craters (GECs), Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2025.180042

Exploding Siberian Craters

Comment by Dr. Krishna Kumari Challa 23 hours ago

Man's COVID Infection Lasted 2 Years, Setting a New Record

An immunocompromised man endured ongoing acute COVID-19 for more than 750 days. During this time, he experienced persistent respiratory symptoms and was hospitalized five times.
In spite of its duration, the man's condition differs from long COVID as it wasn't a case of symptoms lingering once the virus had cleared out, but the viral phase of SARS-CoV-2 that continued for over two years.

While this record may be easy to dismiss as something that occurs only to vulnerable people, persistent infections have implications for us all, researchers warn in their new study.

https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(25)00050-3/fulltext

Comment by Dr. Krishna Kumari Challa 23 hours ago

Researchers used two different and powerful methods—single cell RNA sequencing and advanced 3D imaging. They studied samples from both healthy and transplant rejection patients.

Single-cell sequencing allows scientists to study the activity of genes in individual cells, one at a time. The researchers did this on a very large scale to generate a huge amount of data. Then the team stained large chunks of kidney tissue while still intact and used a procedure to make it transparent. This 3D imaging helped validate the predictions from the single-cell genetic analysis.

The researchers found that during kidney transplant rejection, the lymphatic vessels within the transplant change their shape and organization. The vessels spread into deeper parts of the kidney known as the medulla, which normally has no lymphatic vessels within it. At the same time, the cell junctions, which are protein anchors that connect cells, go from looking like loose buttons to tightening up like zippers. This is a change that in other contexts is associated with immune cells getting trapped and unable to escape.

Additionally, the researchers found that the balance of T cells inside and around the vessels was disrupted. These T cells released signals that made the vessels switch on molecules acting like "brakes" for the immune system, in an attempt to calm inflammation. However, this protective response was not enough, as other immune cells and antibodies were seen to be directly attacking the kidney. Strikingly, the vessels themselves were also carrying signs that they too were being targeted by the same harmful antibodies.
These findings challenge the view that lymphatic vessels are simply good or bad in transplant rejection. This study suggests that the lymphatic system is normally protective but impaired in transplant rejection as the findings show the vessels change in ways that could encourage rejection by altering their structure and fueling immune responses. The results pave the way for research to focus on regenerating or protecting the lymphatic system in chronic kidney rejection.

Daniyal J. Jafree et al, Organ-specific features of human kidney lymphatics are disrupted in chronic transplant rejection, Journal of Clinical Investigation (2025). DOI: 10.1172/jci168962

Part 2

Comment by Dr. Krishna Kumari Challa 23 hours ago

Kidney transplant rejection associated with changes in lymphatic vessels, new research shows

Scientists have uncovered how lymphatic vessels—the kidney's "plumbing system"—undergo dramatic changes during chronic transplant rejection, becoming structurally disorganized and spreading to unusual parts of the kidney.

Researchers used single-cell sequencing combined with powerful 3D imaging to look at small lymphatic vessels in kidney tissue, comparing healthy kidneys with transplanted kidneys that had been rejected.

Published in the Journal of Clinical Investigation, the research sheds new light on a major unsolved challenge in kidney transplantation and could open the door to new treatments that help transplants last longer.
Kidney transplantation is the most common form of solid organ transplant worldwide. Although the short-term outcomes of kidney transplantation—within a year after surgery—are very good, the long-term outcomes are poorer. Within 10 years, and depending on what country patients are treated in, roughly 50% of kidney grafts will fail.

Researchers know that a big component of why kidney transplant failure occurs is that the patient's immune system attacks parts of the new kidney—such as the blood vessels within it. However, the role of the lymphatic vessels is far less understood. In healthy kidneys, lymphatic vessels act as the organ's plumbing system—playing a vital role in draining excess fluid and helping to regulate immune activity. Therefore, the researchers sought to gain a deeper understanding of the lymphatic system during transplant rejection.

Part 1

Comment by Dr. Krishna Kumari Challa 23 hours ago

Similarities in the structure of the T2Rs were also analyzed for this study. For these receptors, part of the protein remains inside the cell, known as the intracellular region, while another part stays outside the cell (extracellular region). The interaction with signal molecules happens in the extracellular region. The study demonstrated that there are more structural similarities and consistencies among the intracellular regions of the T2Rs. The extracellular region of the receptors shows significant structural variation.
"Clustering of proteins is based on their structural similarity and dissimilarity. Based on their findings, the researchers divided the T2Rs into three different clusters.
The structure of T2Rs probably allows them to recognize the thousands of different bitter substances via interaction with another taste receptor-specific G protein, α-gustducin.

"With the receptors' involvement in detecting bitter tastants and maintaining the gut-brain axis, this can play an important role in health and pharmaceutical-based research, specifically targeting lifestyle diseases like diabetes.

 Takafumi Shimizu et al, The three-dimensional structure prediction of human bitter taste receptor using the method of AlphaFold3, Current Research in Food Science (2025). DOI: 10.1016/j.crfs.2025.101146

Part 2

**

Comment by Dr. Krishna Kumari Challa 23 hours ago

Scientists use AI to decode protein structures behind bitter taste detection

Receptor proteins, expressed on the cell surface or within the cell, bind to different signaling molecules, known as ligands, initiating cellular responses. Taste receptors, expressed in oral tissues, interact with tastants, the molecules responsible for the sensation of taste.

Bitter taste receptors (T2Rs) are responsible for the sensation of bitter taste. However, apart from oral tissue, these receptors are also expressed in the neuropod cells of the gastrointestinal tract, which are responsible for transmitting signals from the gut to the brain. Thus, T2Rs might play a crucial role in maintaining the gut-brain axis.

25 types of human T2Rs have been identified to date. However, due to certain complexities, the structure of most of these receptors is not yet elucidated. In recent times, AI-based prediction models have been used to understand protein structure accurately. Previously, a Nobel Prize-winning artificial intelligence (AI)-based model, AlphaFold2 (AF2), was utilized to decipher the structures of T2Rs. However, with the advancement in technology, the model has been updated to its latest version, AlphaFold3 (AF3). The latest model allows a more detailed structural prediction compared to the previous version.

In this study, a group of researchers decided to analyze the structure of T2Rs using the AF3 model and compare the accuracy with the results from the AF2-based prediction study and the available three-dimensional structures of the two T2Rs, T2R14 and T2R46.

The expression of bitter taste receptors in the gastrointestinal tract indicates that they are involved in maintaining the gut-brain axis, glucose tolerance, and appetite regulation. Hence, understanding the structure can provide a better insight into its function.

The researchers obtained the amino acid sequences of all human T2Rs from the UniProt database and used the AF3 model to predict their three-dimensional structures. For comparison, previously generated AF2 prediction data were retrieved from the AlphaFold database. The experimentally determined structures of T2R14 and T2R46 were sourced from the Protein Data Bank (PDB). Various software tools were employed for structure visualization, alignment, and accuracy assessment.

The analysis revealed that AF3 provided consistently more accurate structural predictions than AF2. For T2R14, predictions were benchmarked against 115 cryo-EM structures, and AF3 showed a higher agreement with experimental data. Similarly, for T2R46, comparisons with three experimentally resolved structures confirmed that AF3 achieved the closest match in all cases.

Part1

Comment by Dr. Krishna Kumari Challa yesterday

Geologists discover where energy goes during an earthquake

The ground-shaking that an earthquake generates is only a fraction of the total energy that a quake releases. A quake can also generate a flash of heat, along with a domino-like fracturing of underground rocks. But exactly how much energy goes into each of these three processes is exceedingly difficult, if not impossible, to measure in the field.

Earthquakes are driven by energy that is stored up in rocks over millions of years. As tectonic plates slowly grind against each other, stress accumulates through the crust. When rocks are pushed past their material strength, they can suddenly slip along a narrow zone, creating a geologic fault. As rocks slip on either side of the fault, they produce seismic waves that ripple outward and upward.

We perceive an earthquake's energy mainly in the form of ground shaking, which can be measured using seismometers and other ground-based instruments. But the other two major forms of a quake's energy—heat and underground fracturing—are largely inaccessible with current technologies.

Now  geologists have traced the energy that is released by "lab quakes"—miniature analogs of natural earthquakes that are carefully triggered in a controlled laboratory setting. For the first time, they have quantified the complete energy budget of such quakes, in terms of the fraction of energy that goes into heat, shaking, and fracturing.

They found that only about 10% of a lab quake's energy causes physical shaking. An even smaller fraction—less than 1%—goes into breaking up rock and creating new surfaces. The overwhelming portion of a quake's energy—on average 80%—goes into heating up the immediate region around a quake's epicenter. In fact, the researchers observed that a lab quake can produce a temperature spike hot enough to melt surrounding material and turn it briefly into liquid melt.

The geologists also found that a quake's energy budget depends on a region's deformation history—the degree to which rocks have been shifted and disturbed by previous tectonic motions. The fractions of quake energy that produce heat, shaking, and rock fracturing can shift depending on what the region has experienced in the past.

The team's lab quakes are a simplified analog of what occurs during a natural earthquake. Down the road, their results could help seismologists predict the likelihood of earthquakes in regions that are prone to seismic events.

 Daniel Ortega‐Arroyo et al, "Lab‐Quakes": Quantifying the Complete Energy Budget of High‐Pressure Laboratory Failure, AGU Advances (2025). DOI: 10.1029/2025av001683

Comment by Dr. Krishna Kumari Challa yesterday

Comment by Dr. Krishna Kumari Challa yesterday

Scientists shoot lasers into brain cells to uncover how illusions work

An illusion is when we see and perceive an object that doesn't match the sensory input that reaches our eyes.

In a new study published in Nature Neuroscience, researchers identified the key neural circuit and cell type that plays a pivotal role in detecting these illusions—more specifically, their outer edges or "contours"—and how this circuit works.

They discovered a special group of cells called IC–encoder neurons that tell the brain to see things that aren't really there as part of a process called recurrent pattern completion.

Because IC–encoder neurons have this unique capacity to drive pattern completion, the researchers think that they might have specialized synaptic output connectivity that allows them to recreate this pattern in a very effective manner.

They also also know that they receive top-down inputs from higher visual areas. The representation of the illusion arises in higher visual areas first and then gets fed back to the primary visual cortex; and when that information is fed back, it's received by these IC–encoders in the primary visual cortex.

 In the context of the brain and vision—using the above shape diagram—higher levels of the brain interpret the image as a square and then tell the lower-level visual cortex to "see a square" even though the visual stimulus consists of four semi-complete black circles.

They made the discovery by observing the electrical brain activity patterns of mice when they were shown illusory images like the Kanizsa triangle. They then shot beams of light at the IC-encoder neurons, in a process called two-photon holographic optogenetics, when there was no illusory image present.

When this happened, they noticed that even in the absence of an illusion, IC-encoder neurons triggered the same brain activity patterns that exist when an illusory image was present. They successfully emulated the same brain activity by stimulating these specialized neurons.

The findings shed light on how the visual system and perception work in the brain and have implications for diseases where this system malfunctions. In certain diseases you have patterns of activity that emerge in your brain that are abnormal, and in schizophrenia these are related to object representations that pop up randomly.

If you don't understand how those objects are formed and a collective set of cells work together to make those representations emerge, you're not going to be able to treat it; so understanding which cells and in which layer this activity occurs is helpful.

Recurrent pattern completion drives the neocortical representation of sensory inference, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02055-5.

• ‹ Previous
• 1
• 2
• 3
• …
• 1112
• Next ›
• Page