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Comment by Dr. Krishna Kumari Challa 15 hours ago

Carbon in our bodies likely left galaxy and came back!

Life on Earth could not exist without carbon. But carbon itself could not exist without stars. Nearly all elements except hydrogen and helium—including carbon, oxygen and iron—only exist because they were forged in stellar furnaces and later flung into the cosmos when their stars died. In an ultimate act of galactic recycling, planets like ours are formed by incorporating these star-built atoms into their makeup, be it the iron in Earth's core, the oxygen in its atmosphere or the carbon in the bodies of Earthlings.

A team of scientists  recently confirmed that carbon and other star-formed atoms don't just drift idly through space until they are dragooned for new uses. For galaxies like ours, which are still actively forming new stars, these atoms take a circuitous journey. They circle their galaxy of origin on giant currents that extend into intergalactic space.

These currents—known as the circumgalactic medium—resemble giant conveyer belts that push material out and draw it back into the galactic interior, where gravity and other forces can assemble these raw materials into planets, moons, asteroids, comets and even new stars.

The heavy elements that stars make get pushed out of their host galaxy and into the circumgalactic medium through their explosive supernovae deaths, where they can eventually get pulled back in and continue the cycle of star and planet formation.

So the same carbon in our bodies most likely spent a significant amount of time outside of the galaxy.

 Samantha L. Garza et al, The CIViL* Survey: The Discovery of a C iv Dichotomy in the Circumgalactic Medium of L* Galaxies, The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad9c69

Comment by Dr. Krishna Kumari Challa 15 hours ago

Plastic crystals could replace greenhouse gases used in refrigerators

A team of chemical engineers  has found that a type of plastic crystal can be used as a refrigerant, possibly replacing the greenhouse gas currently used in most refrigerators. Their study is published in the journal Science.

The most commonly used gas in modern refrigerators is R-134a, a hydrofluorocarbon that has largely replaced freon. And while it does not contribute to the breakdown of the Earth's ozone layer, it is a greenhouse gas and thus, as it leaks from refrigerators, contributes to global warming. In this new effort, the researchers have found a possible replacement—one that is not even a gas.

The idea involves the use of "plastic crystals"—so named because once they are grown, their molecules can move under certain conditions. Prior research had shown that when pressurized, the molecules in organic ionic crystals move from a disorganized state to a neat grid configuration. When pressure is released, the molecules return to their disorganized state. More importantly, when they are pressed into an organized state, the crystals absorb heat, which chills the air around them.

In their work, the researchers tested several types of such crystals to find one that viably chills the air around it when compressed at ambient temperatures. They found several that were capable of pulling heat from the air at temperatures ranging from -37°C to 10°C.

To use the crystals as a refrigerant, the researchers built a compression chamber to squeeze the crystals and added a fan to blow the chilled air into the area around the device. By repeatedly squeezing and un-squeezing the crystals, the researchers found they functioned as a clean refrigerant. They acknowledge that more work is required due to the extreme amount of pressure needed to squeeze the crystals, making it an expensive way to cool a home.

 Samantha L. Piper et al, Organic ionic plastic crystals having colossal barocaloric effects for sustainable refrigeration, Science (2025). DOI: 10.1126/science.adq8396

Josep-Lluís Tamarit et al, Compressed ionic plastic crystals are cool, Science (2025). DOI: 10.1126/science.adu3670

Comment by Dr. Krishna Kumari Challa yesterday

Researchers reveal why the lung is a frequent site of cancer metastasis

More than half of cancer patients in whom the cancer spreads beyond the primary site have lung metastases. What makes the lungs such a tempting place for cancer cells?

To find out, researchers investigated the gene expression in cells from aggressive lung metastases. They found evidence for an alternative translation program. Translation is the process that uses our genetic code as a blueprint to make proteins in cells. A change in the translational program results in a set of different proteins that allow cancer cells to grow easier in the lung environment

They  found high levels of aspartate in the lungs of mice and patients with breast cancer compared to mice and patients without cancer, which suggests that aspartate may be important for lung metastasis.

Aspartate is an amino acid (a protein building block) that has very low concentrations in blood plasma but, surprisingly, very high concentrations in the lungs of mice with metastatic breast cancer.

Many proteins in our bodies can affect the translation process, among them the so-called initiation factors. One such initiation factor is eIF5A, which kickstarts translation. In the cells of cancer cells within lung metastases, the researchers found an activating modification to eIF5A called "hypusination," which was associated with higher cancer aggressiveness of lung metastases.

Aspartate has something to do with this. The researchers discovered that aspartate triggered this modification on eIF5A through an unexpected mechanism. Surprisingly, aspartate was not taken up by the cancer cells. Instead, it activated a cell surface protein called an NMDA receptor in cancer cells, leading to a signaling cascade that eventually triggered eIF5A hypusination.

This subsequently drives a translational program that enhances the ability of cancer cells to change their environment and make it more suitable for aggressive growth.

Looking at human lung tumor samples from patients with metastatic breast cancer, the scientists noted a similar translational program as in mice and an elevated expression of the NMDA receptor subunit that binds aspartate compared to metastases from other organs.

 Ginevra Doglioni et al, Aspartate signalling drives lung metastasis via alternative translation, Nature (2025). DOI: 10.1038/s41586-024-08335-7

Comment by Dr. Krishna Kumari Challa yesterday

In the new study, the team studied brain imaging, clinical data, and blood markers of angiogenesis, including the family of VEGF growth factors and their receptors. VEGF stands for vascular endothelial growth factor. VEGF is critically necessary for angiogenesis and plays a central role in stimulating the growth and development of new blood vessels.

There are multiple types of VEGF that contribute to angiogenesis, with the most prominent being VEGF-A, but also VEGF-B, VEGF-C and placental growth factor, PlGF. Each has a slightly different role and binding affinity to VEGF receptors.
The research identified two main pathways to brain abnormalities—aberrant angiogenesis and sex-specific patterns in the trajectories of VEGF growth factors in the brain.

"The trajectories of some markers of angiogenesis are associated with better executive function and less brain atrophy in younger women, but not in men. However, these trajectories reversed at the age of 75, suggesting that both sex and age are critical variables for future study.
The study revealed that angiogenesis markers weren't the only ones that showed differences across a gender divide. For example, about 30% of participants were carriers of the APOE4 genotype with significant differences between men and women.

APOE4 is strongly associated with an increased risk of developing Alzheimer's disease. In the study, men represented a higher proportion of APOE4 carriers—34.2%—compared with 25.6% among women. APOE4 is also linked with elevated cholesterol levels, particularly low-density lipoprotein, or LDL, the so-called bad form of the compound, which is additionally associated with obstructed arteries.

At the beginning of the research project, the Clinical Dementia Rating scale showed that 73% of participants were considered to be functionally normal with no evidence of cognitive impairment or dementia at first visit. However, by the end of the study, only 66% were considered functionally normal. The average age was 71 at the beginning of the analysis, and 77 by the end of the study.

There were statistically significant differences between men and women for Clinical Dementia Rating scores at both first and last visit. A higher proportion of men presented with signs of cognitive impairment at both visits.

Abel Torres-Espin et al, Sexually dimorphic differences in angiogenesis markers are associated with brain aging trajectories in humans, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adk3118

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Abnormal blood vessel growth in the brain may be an early diagnostic sign of cognitive impairment

Gender differences define how the human brain ages, and telltale biomarkers in the blood may be strongly suggestive of cognitive impairment and dementia, according to a comprehensive new study involving more than 500 people.

Just as skin wrinkles and muscles sag, the human body's massive network of vasculature can be waylaid by the vagaries of age. Indeed, growing older can impact the very process by which healthy new blood vessels are made, resulting in aberrant angiogenesis—an abnormal and disordered formation of new vasculature.

A team of neuroscientists  was able to uncover differences in brain aging between men and women by pinpointing biomarkers—fragments of blood vessel growth factors—the remains of aberrant angiogenesis in their blood. These scientists suggest that an ailing angiogenesis system offers a new target for early intervention against neurodegenerative disorders.

Aberrant angiogenesis can contribute to the development of cognitive impairment the  new analysis published in Science Translational Medicine says.

Many forms of dementia and cognitive impairment are linked to abnormalities in small vessels and capillaries in the brain. Vascular dementia is a prime example of a brain disorder that develops as a direct consequence of blood vessel impairment. But Alzheimer's disease is among a host of others that are also marked by damaged vasculature in the brain.

As people age, vessels can lose their tensile strength as well as undergo a decline in density, and this can be accompanied by an overall slowdown in angiogenesis. While these problems do not become pervasive for many people, for some they contribute to irreversible brain disorders.

With aging, numerous pathologies result in abnormal blood vessels across calibers of vessels, from capillaries to large vessels. The pathologies present in small blood vessels are among the most insidious and yet most prevalent and detrimental consequences of aging.

 The task now, they say, is to conduct additional studies to tease out how to exploit aberrant angiogenesis as a druggable target.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

How does a hula hoop master gravity? Mathematicians prove that body shape matters

Hula hooping is so commonplace that we may overlook some interesting questions it raises: "What keeps a hula hoop up against gravity?" and "Are some body types better for hula hooping than others?" A team of mathematicians explored and answered these questions with findings that also point to new ways to better harness energy and improve robotic positioners.

The results are the first to explain the physics and mathematics of hula hooping.

A paper based on the results appears in the Proceedings of the National Academy of Sciences.

The researchers tested different shapes and motions in a series of experiments on robotic hula hoopers using 3D-printed bodies of different shapes (e.g., cylinders, cones, hourglass shapes) to represent human forms at one-tenth the size.

These shapes were driven to gyrate by a motor, replicating the motions we take when hula hooping. Hoops approximately 6 inches in diameter were launched on these bodies, with high-speed video capturing the movements.

The results showed that the exact form of the gyration motion or the cross-section shape of the body (circle versus ellipse) wasn't a factor in hula hooping.

In all cases, good twirling motions of the hoop around the body could be set up without any special effort.

However, keeping a hoop elevated against gravity for a significant period of time was more difficult, requiring a special "body type"—one with a sloping surface as "hips" to provide the proper angle for pushing up the hoop and a curvy form as a "waist" to hold the hoop in place.

The  results explain why some people are natural hoopers and others seem to have to work extra hard.

The paper's authors conducted mathematical modeling of these dynamics to derive formulas that explained the results—calculations that could be used for other purposes.

 The math and physics involved are very subtle, and the knowledge gained could be useful in inspiring engineering innovations, harvesting energy from vibrations, and improving robotic positioners and movers used in industrial processing and manufacturing.

Xintong Zhu et al, Geometrically modulated contact forces enable hula hoop levitation, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2411588121

Comment by Dr. Krishna Kumari Challa on Wednesday

Needle-Free Shock Syringes for painless medical treatments

Medical practitioners have been using needles to inject medicines into human bodies for decades. But no one likes getting pricked, be it children or adults. In some cases, the fear is so strong, especially in children, that many miss out on vaccinations and other medical treatments. For patients who have diabetes, the stress is even greater as they may require frequent insulin injections. 

As a relief to patients, a team of researchers led by Prof. Viren Menezes from the Department of Aerospace Engineering at the Indian Institute of Technology Bombay (IIT Bombay) has now worked a way around to deliver drugs without needles by developing a shock syringe. In their study published in the Journal of Biomedical Materials & Devices, the IIT Bombay researchers compared the effectiveness of drug delivery by a shock syringe versus a regular needle on laboratory rats. 

Unlike syringes with needles, the shock syringe doesn’t rely on piercing the skin with a sharp tip. Instead, it uses high-energy pressure waves (shock waves) that can travel faster than the speed of sound to pierce the skin. These waves, when generated, compress the surrounding medium (such as air or liquid) through which they travel. A similar effect happens during a sonic boom; when an aircraft flies faster than the speed of sound, it creates shock waves that push and disturb the air.

The shock syringe, developed earlier in 2021 in Prof. Menezes’ lab, is slightly longer than a regular ballpoint pen. The device has a micro shock tube consisting of three sections: the driver, driven, and drug holder, which work together to create the shockwave-driven microjet for drug delivery. Pressurised nitrogen gas is applied to the shock syringe (driver section of micro shock tube part) filled with liquid drugs to create a microjet of the drug. The microjet travels at a speed nearly twice as fast as a commercial aeroplane at takeoff. This jet stream of liquid drug passes through the nozzle of the syringe before penetrating the skin. The entire process of delivering drugs using a shock syringe is rapid and gentle; most patients wouldn’t feel a thing.

To minimise tissue damage and ensure consistent and precise drug delivery, the pressure in the shock syringe is continuously monitored. Additionally, the researchers have optimised the nozzle design to have an opening of just 125 μm (roughly the width of a human hair).

The development of a shock syringe promises more than pain-free injections. It could make immunization drives quicker and more efficient for both children and adults. It could prevent the occurrence of bloodborne diseases caused by needle-stick injuries due to mishandling or improper disposal.

https://link.springer.com/article/10.1007/s44174-024-00239-4

Comment by Dr. Krishna Kumari Challa on Wednesday

Animal studies have shown its potential as an endocrine disruptor, affecting pregnancy in mice and puberty in rats. A study published back in 2022 found a significant link between increased DEHP metabolites in the urine samples of 5303 US adults and an increase in mortality rate. This recent study calculates 164,000 deaths worldwide could be related to DEHP exposure, with an estimated US$398 billion in equivalent economic losses.

PBDEs are a class of brominated flame retardants controversially behind advice to throw out your black plastic spatula. Common in materials that are exposed to high levels of heat, they're also present in electronics, car parts, aircraft, and certain textiles.

They can enter your body by inhalation, dermal absorption, or via your food – a seemingly unlikely route, but they've turned up in utensils, food packaging, and children's toys made from recycled black plastic.
A correlation between PBDE exposure and measures of intelligence suggests almost 12 million collective IQ points may have been lost due to maternal PBDE exposure.
The cumulative impact, it seems, is damning. BPA and DEHP may be eliminated from the body relatively quickly over a course of days, but the continuous stream of plastics in our lives means we have little relief from their exposure. The 'stickiness' of PBDE in our bodies is less clear, and depends on the specific chemical makeup.
All of the study's estimates lean heavily on the data from existing observational studies, making causation difficult to confirm. Some unrelated factor might increase people's exposure to the chemicals as well as their health problems – a diet high in fast food, for instance, would increase a person's exposure to plastics and is also known to increase the risk of cardiovascular disease.

https://www.pnas.org/doi/epub/10.1073/pnas.2412714121

Part 2

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Comment by Dr. Krishna Kumari Challa on Wednesday

Common Plastic Additives May Have Affected The Health of Millions

Exposure to a trio of chemicals found in many everyday household and industrial items may have contributed to millions of cases of heart disease, stroke, and deaths over the years according to estimations of the health and economic impacts of common plastic additives.

An international team of researchers pooled findings from over 1,700 existing studies from 38 different countries investigating links between people's exposure to the chemicals and certain health impacts.

The researchers argue the results are concerning enough to warrant global action, but critics say we still need conclusive proof that these chemicals are the true cause.

The suspects in question – BPA (bisphenol A), DEHP (di(2-ethylhexyl) phthalate) and PBDEs (polybrominated diphenyl ethers) – have been previously associated with serious health issues.

The safety of BPA has been questioned for a while: widespread in our food packaging, especially in the form of the epoxy that lines some food and drink cans and bottles, exposure to this compound has been linked to higher rates of ischemic heart disease and stroke.

This latest study found 5.4 million cases of ischemic heart disease and 346,000 cases of stroke in 2015 could be associated with BPA exposure. That suggests BPA exposure could be associated with 431,000 deaths. An estimate on the total economic impact suggests the resulting loss in health could have cost nations an equivalent of US$1 trillion in purchasing power.

DEHP is present in the flexible plastics of garden hoses, shower curtains, medical tubing, and synthetic leathers.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

Although the researchers suspected estrogen would have an effect on drinking, they were surprised by its mechanism of action. This steroid hormone typically regulates behaviours by binding to receptors that then travel to the nucleus, where they alter the activity of specific genes—a process that could take hours.

However, researchers now realized that something else must be happening when estrogen infused directly into the BNST excited the neurons and triggered binge drinking within minutes.

So, the researchers tested estrogen that had been doctored so it could not enter cells and bind to nuclear receptors—a feat of chemical engineering performed by Dr. Jacob Geri, assistant professor of pharmacology at Weill Cornell Medicine. They determined that when estrogen promotes binging, the hormone is binding to receptors on the neurons' surface, where it directly modulates cell-cell communication.
This is the first time that anybody has shown that during a normal estrous cycle, endogenous estrogen made by the ovaries can use such a rapid mechanism to control behaviour.
The team identified the estrogen receptor that mediates this effect and determined that it is expressed in the excited BNST neurons and in neurons from other brain regions that excite them. The researchers are now investigating the signaling mechanisms for this effect, and they will also examine whether the same system regulates drinking in males.

 Lia J. Zallar et al, Rapid nongenomic estrogen signaling controls alcohol drinking behavior in mice, Nature Communications (2024). DOI: 10.1038/s41467-024-54737-6

Part 3

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