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Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:44am

Promising evidence of deuterium forming into a metallic state at high pressure

A trio of researchers at the French Alternative Energies and Atomic Energy Commission has shown promising evidence of deuterium forming into a metallic state at high pressure. In their paper published in the journal Physical Review Letters, researchers describe the process they used to pressurize a deuterium sample and test it for a transition state. Theory suggests that all elements should transition to a metallic state if subjected to strong enough pressure. This is because at some point, their electrons will become delocalized. But modeling, much less demonstrating, such transition points has proven to be difficult. Early research looking for the transition state of hydrogen led to theories that it would reach a metallic state when hydrogen molecules disassociated completely. That led to many efforts to see if such theories were true—sadly, none were successful. Then in 2000, a team at Cornell University calculated that hydrogen should transition at 410 GPa. In 2020, the researchers of the current study used a diamond anvil cell to compress a sample of hydrogen to 425 GPa and used synchrotron infrared absorption and Raman spectroscopy to measure the band gap of the material. They found a sudden drop from 0.6eV to 0.1eV at 80K, comprising promising evidence of hydrogen forming into a metallic state as theorized. A short time later, physicist Alexander Goncharov suggested that transitions should happen more easily under conditions where quantum motion could allow for some atoms to tunnel from one place to another. Noting that deuterium nuclei are heavier than hydrogen, the researchers reasoned that they should be less delocalized than protons and thus should require more pressure to transition. To find out if that was the case, the team reran their 2020 effort, only this time, they used deuterium instead of hydrogen. They found the band gap decreased in ways similar to the hydrogen experiment, but it did so at 460 GPa, possibly confirming the theory. The researchers noted that they also saw nothing that would indicate molecular disassociation had occurred in either experiment.

Paul Loubeyre et al, Compression of D2 to 460 GPa and Isotopic Effects in the Path to Metal Hydrogen, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.129.035501

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Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:30am

Alarm as Earth hits 'Overshoot Day' Thursday: NGOs

Mankind marks a dubious milestone Thursday (yesterday), the day by which humanity has consumed all earth can sustainably produce for this year, with NGOS warning the rest of 2022 will be lived in resource deficit.

The date—dubbed "Earth Overshoot Day"—marks a tipping point when people have used up "all that ecosystems can regenerate in one year", according to the Global Footprint Network and WWF.

From January 1 to July 28, humanity has used as much from nature as the planet can renew in the entire year. That's why this July 28 is Earth Overshoot Day.

The Earth has a lot of stock, so we can deplete Earth for some time but we cannot overuse it for ever. It's like with money; we can spend more than we earn for some time until we're broke."

It would take 1.75 Earths to provide for the world's population in a sustainable way, according to the measure, which was created by researchers in the early 1990s.

Global Footprint Network said Earth Overshoot Day has fallen ever sooner over the last 50 years.

Source: News Agencies

Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:19am

Engineers develop stickers that can see inside the body

Ultrasound imaging is a safe and noninvasive window into the body's workings, providing clinicians with live images of a patient's internal organs. To capture these images, trained technicians manipulate ultrasound wands and probes to direct sound waves into the body. These waves reflect back out to produce high-resolution images of a patient's heart, lungs, and other deep organs.

Currently, ultrasound imaging requires bulky and specialized equipment available only in hospitals and doctor's offices. But a new design by MIT engineers might make the technology as wearable and accessible as buying Band-Aids at the pharmacy.

In a paper appearing recently in Science, the engineers present the design for a new ultrasound sticker—a stamp-sized device that sticks to skin and can provide continuous ultrasound imaging of internal organs for 48 hours.

The researchers applied the stickers to volunteers and showed the devices produced live, high-resolution images of major blood vessels and deeper organs such as the heart, lungs, and stomach. The stickers maintained a strong adhesion and captured changes in underlying organs as volunteers performed various activities, including sitting, standing, jogging, and biking.

The current design requires connecting the stickers to instruments that translate the reflected sound waves into images. The researchers point out that even in their current form, the stickers could have immediate applications: For instance, the devices could be applied to patients in the hospital, similar to heart-monitoring EKG stickers, and could continuously image internal organs without requiring a technician to hold a probe in place for long periods of time.

If the devices can be made to operate wirelessly—a goal the team is currently working toward—the ultrasound stickers could be made into wearable imaging products that patients could take home from a doctor's office or even buy at a pharmacy.

Chonghe Wang et al, Bioadhesive ultrasound for long-term continuous imaging of diverse organs, Science (2022). DOI: 10.1126/science.abo2542. www.science.org/doi/10.1126/science.abo2542

Philip Tan et al, Seeing inside a body in motion, Science (2022). DOI: 10.1126/science.adc8732. www.science.org/doi/10.1126/science.adc8732

Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:09am

Earlier this year, Krishnamurthy's group showed how cyanide can enable the chemical reactions that turn prebiotic molecules and water into basic organic compounds required for life. Unlike previously proposed reactions, this one worked at room temperature and in a wide pH range. The researchers wondered whether, under the same conditions, there was a way to generate amino acids, more complex molecules that compose proteins in all known living cells.

In cells today, amino acids are generated from precursors called α-keto acids using both nitrogen and specialized proteins called enzymes. Researchers have found evidence that α-keto acids likely existed early in Earth's history. However, many have hypothesized that before the advent of cellular life, amino acids must have been generated from completely different precursors, aldehydes, rather than α-keto acids, since enzymes to carry out the conversion did not yet exist. But that idea has led to debate about how and when the switch occurred from aldehydes to α-keto acids as the key ingredient for making amino acids.

After their success using cyanide to drive other chemical reactions, Krishnamurthy and his colleagues suspected that cyanide, even without enzymes, might also help turn α-keto acids into amino acids. Because they knew nitrogen would be required in some form, they added ammonia—a form of nitrogen that would have been present on the early earth. Then, through trial and error, they discovered a third key ingredient: carbon dioxide. With this mixture, they quickly started seeing amino acids form.

If you mix only the keto acid, cyanide and ammonia, it just sits there. As soon as you add carbon dioxide, even trace amounts, the reaction picks up speed.

Part 2

Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:08am

Scientists discover new 'origins of life' chemical reactions

Four billion years ago, the Earth looked very different than it does today, devoid of life and covered by a vast ocean. Over the course of millions of years, in that primordial soup, life emerged. Researchers have long theorized how molecules came together to spark this transition. Now, scientists have discovered a new set of chemical reactions that use cyanide, ammonia and carbon dioxide—all thought to be common on the early earth—to generate amino acids and nucleic acids, the building blocks of proteins and DNA.

In addition to giving researchers insight into the chemistry of the early earth, the newly discovered chemical reactions are also useful in certain manufacturing processes, such as the generation of custom labeled biomolecules from inexpensive starting materials.

Because the new reaction is relatively similar to what occurs today inside cells—except for being driven by cyanide instead of a protein—it seems more likely to be the source of early life, rather than drastically different reactions, the researchers say. The research also helps bring together two sides of a long-standing debate about the importance of carbon dioxide to early life, concluding that carbon dioxide was key, but only in combination with other molecules.

In the process of studying their chemical soup, the researchers discovered that a byproduct of the same reaction is orotate, a precursor to nucleotides that make up DNA and RNA. This suggests that the same primordial soup under the right conditions, could have given rise to a large number of the molecules that are required for the key elements of life.

 Ramanarayanan Krishnamurthy, Prebiotic synthesis of α-amino acids and orotate from α-ketoacids potentiates transition to extant metabolic pathways, Nature Chemistry (2022). DOI: 10.1038/s41557-022-00999-w. www.nature.com/articles/s41557-022-00999-w

Part 1

Comment by Dr. Krishna Kumari Challa on July 28, 2022 at 10:21am

FNDs

Comment by Dr. Krishna Kumari Challa on July 27, 2022 at 9:35am

Research breakthrough in mystery child hepatitis

Researchers reported a breakthrough this week in mysterious hepatitis cases affecting young children, finding the serious liver condition was linked to co-infection of two common viruses, but not the coronavirus.

The World Health Organization (WHO) has reported at least 1,010 probable cases, including 46 that required transplants and 22 deaths from the illness dating back to last October.

Previous theories had centered on a spike in commonly found adenovirus infections being behind the cases.

But in two new studies carried out independently and simultaneously in Scotland and London, scientists found another virus, AAV2 (adeno-associated virus 2) played a significant role and was present in 96 percent of all patients examined.

AAV2 is not normally known to cause disease and cannot replicate itself without another "helper" virus being present.

Both teams concluded that co-infection with either AAV2 and an adenovirus, or sometimes the herpes virus HHV6, offered the best explanation for the severe liver disease.

The presence of the AAV2 virus is associated with unexplained hepatitis in children. also cautioned it was not yet certain whether AAV2 was causing the disease or was rather a biomarker for underlying adenovirus infection that is harder to detect but was the main pathogen.

Both papers have been posted online to "preprint" servers and still await peer review before they are published in journals.

https://media.gosh.nhs.uk/documents/MEDRXIV-2022-277963v1-Breuer.pdf

https://www.medrxiv.org/content/10.1101/2022.07.19.22277425v1

https://medicalxpress.com/news/2022-07-breakthrough-mystery-child-h...

Comment by Dr. Krishna Kumari Challa on July 27, 2022 at 9:24am

Natural clean-up: Bacteria can remove plastic pollution from lakes

A study of 29 European lakes has found that some naturally-occurring lake bacteria grow faster and more efficiently on the remains of plastic bags than on natural matter like leaves and twigs.

The bacteria break down the carbon compounds in plastic to use as food for their growth.

The scientists say that enriching waters with particular species of bacteria could be a natural way to remove plastic pollution from the environment.

The effect is pronounced: the rate of bacterial growth more than doubled when plastic pollution raised the overall carbon level in lake water by just 4%.

The results suggest that the plastic pollution in lakes is 'priming' the bacteria for rapid growth— the bacteria are not only breaking down the plastic but are then more able to break down other natural carbon compounds in the lake.

Lake bacteria were found to favor plastic-derived carbon compounds over natural ones. The researchers think this is because the carbon compounds from plastics are easier for the bacteria to break down and use as food.

The scientists caution that this does not condone ongoing plastic pollution. Some of the compounds within plastics can have toxic effects on the environment, particularly at high concentrations.

Eleanor Sheridan, Plastic pollution fosters more microbial growth in lakes than natural organic matter, Nature Communications (2022). DOI: 10.1038/s41467-022-31691-9. www.nature.com/articles/s41467-022-31691-9

Comment by Dr. Krishna Kumari Challa on July 26, 2022 at 9:47am

Researchers identify how cells move faster through mucus than blood

Researchers  have discovered that certain cells move surprisingly faster in thicker fluid—think honey as opposed to water, or mucus as opposed to blood—because their ruffled edges sense the viscosity of their environment and adapt to increase their speed.

Their combined results in cancer and fibroblast cells—the type that often creates scars in tissues—suggest that the viscosity of a cell's surrounding environment is an important contributor to disease, and may help explain tumor progression, scarring in mucus-filled lungs affected by cystic fibrosis, and the wound-healing process.

The study, "Membrane ruffling is a mechanosensor of extracellular fluid viscosity," published today in Nature Physics, sheds new light on cell environments, an under-explored area of research.

The study found that the thicker the surrounding environment, the stronger the cells adhere to the substrate and the faster they move—much like walking on an icy surface with shoes that have spikes, versus shoes with no grip at all.

Jian Liu, Membrane ruffling is a mechanosensor of extracellular fluid viscosity, Nature Physics (2022). DOI: 10.1038/s41567-022-01676-y. www.nature.com/articles/s41567-022-01676-y

Comment by Dr. Krishna Kumari Challa on July 26, 2022 at 9:42am

Scientists blunt the impact of natural killer cells to improve vaccine effectiveness

Scientists have discovered that the body's own natural killer cells can suppress the immune benefits of therapeutic vaccines, a problem that can affect inoculations against chronic viral infections and cancer.

Indeed, the scientific literature is replete with examples of otherwise effective vaccines sometimes proving impotent. Increasingly, the reasons are pointing to an enemy within the body itself: a friend that transforms into a foe.

Scientists have been investigating the conundrum and have turned to an animal model to decipher how natural killer cells inadvertently blunt the benefits of vaccines.

In Science Translational Medicine, researchers report that natural killer cells can react so overwhelmingly after vaccination that they negatively impact a critical constituent of the immune response—CD8+T cells. This vital population can become overworked and exhausted, they found, a phenomenon that causes vaccination to have little effectiveness.

Therapeutic vaccines for chronic infections have reduced efficacy because of the presence of exhausted T cells and [an] environment that limits vaccine response. The problem invariably begins with the aggression of natural killer cells.

Working with a mouse model, scientists have found that a combination treatment can boost robust immune responses after vaccination by acting on natural killer cells. The strategy, the team said, may eventually prove useful in the design and improvement of therapeutic vaccines for chronic viral infections and cancers.

Mariana O. Diniz et al, NK cells limit therapeutic vaccine–induced CD8 + T cell immunity in a PD-L1–dependent manner, Science Translational Medicine (2022). DOI: 10.1126/scitranslmed.abi4670

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