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Comment by Dr. Krishna Kumari Challa on April 15, 2022 at 12:47pm

The time-of-flight neutron spectrometer Pelican at ANSTO's Center for Neutron Scattering has been used to measure the vibrational densities of states for several liquid systems including water, liquid metal, and polymer liquids. The Pelican instrument has the extreme sensitivity to measure rotational and translational vibrations over short time intervals and at low energies.

The experiments at ANSTO confirmed the linear relationship of the vibrational density of states with frequency at low energies as predicted earlier.

Caleb Stamper et al, Experimental Confirmation of the Universal Law for the Vibrational Density of States of Liquids, The Journal of Physical Chemistry Letters (2022). DOI: 10.1021/acs.jpclett.2c00297

Alessio Zaccone et al, Universal law for the vibrational density of states of liquids, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2022303118

https://phys.org/news/2022-04-surfing-atomic-scale-scientists-exper...

Part 2

Comment by Dr. Krishna Kumari Challa on April 15, 2022 at 12:46pm

Scientists experimentally confirm new fundamental law for liquids

The first experimental evidence to validate a newly published universal law that provides insights into the complex energy states for liquids has been found using an advanced nuclear technique.

 

The equation for the vibrational density of states formulated by Alessio Zaccone and Matteo Bagglioli was published in a paper in PNAS in 2021, providing an answer to a question that has been elusive for at least a century.

The elegant mathematical theory has solved the problem of obtaining the distribution of these complex energy states for liquids.

"One of the most important quantities in the physics of matter is the distribution of the frequencies or vibrational energies of the waves that propagate in the material. It is particularly important as it is the starting point for calculating and understanding some fundamental properties of matter, such as specific heat and thermal conductivity, and the light-matter interaction.

The big problem with liquids is that, in addition to acoustic waves, there are other types of vibrational excitations related to low energies of the disordered motion of atoms and molecules— excitations that are almost absent in solids. These excitations are typically short-lived and are linked to the dynamic chaos of molecular motions but are nevertheless very numerous and important, especially at low energies. Mathematically, these excitations, known as 'instantaneous normal modes' or INMs in the specialized literature are very difficult to deal with as they correspond to energy states described by imaginary numbers.

Part 1

Comment by Dr. Krishna Kumari Challa on April 15, 2022 at 11:47am

 Declining nitrogen availability in a nitrogen rich world

Research and discussion in recent times  has focused on the negative effects of excess nitrogen on terrestrial and aquatic ecosystems. However, new evidence indicates that the world is now experiencing a dual trajectory in nitrogen availability with many areas experiencing a hockey-stick shaped decline in the availability of nitrogen. In a new review paper in the journal Science, researchers have described the causes for these declines and the consequences on how ecosystems function.

There is both too much nitrogen and too little nitrogen on Earth at the same time now. 

Over the last century, humans have more than doubled the total global supply of reactive nitrogen through industrial and agricultural activities. This nitrogen becomes concentrated in streams, inland lakes, and coastal bodies of water, sometimes resulting in eutrophication, low-oxygen dead-zones, and harmful algal blooms. These negative impacts of excess nitrogen have led scientists to study nitrogen as a pollutant. However, rising CO2 and other global changes have increased demand for nitrogen by plants and microbes. In many areas of the world that are not subject to excessive inputs of nitrogen from people, long-term records demonstrate that nitrogen availability is declining, with important consequences for plant and animal growth.

Nitrogen is an essential element in proteins and as such its availability is critical to the growth of plants and the animals that eat them. Gardens, forests, and fisheries are almost all more productive when they are fertilized with moderate amounts of nitrogen. If plant nitrogen becomes less available, plants grow more slowly and their leaves are less nutritious to insects, potentially reducing growth and reproduction, not only of insects, but also the birds and bats that feed on them.

When nitrogen is less available, every living thing holds on to the element for longer, slowing the flow of nitrogen from one organism to another through the food chain. This is why we can say that the nitrogen cycle is slowing down.

Researchers reviewed long-term, global and regional studies and found evidence of declining nitrogen availability. 

These declines are likely caused by multiple environmental changes, one being elevated atmospheric CO2 changes. Atmospheric carbon dioxide has reached its highest level in millions of years, and terrestrial plants are exposed to about 50% more of this essential resource than just 150 years ago. Elevated atmospheric carbon dioxide fertilizes plants, allowing faster growth, but diluting plant nitrogen in the process, leading to a cascade of effects that lower the availability of nitrogen. On top of increasing atmospheric CO2, warming and disturbances, including wildfire, can also reduce availability over time.

Declining nitrogen availability is also likely constraining the ability of plants to remove carbon dioxide from the atmosphere.

Rachel E. Mason et al, Evidence, Causes, and Consequences of Declining Nitrogen Availability in Terrestrial Ecosystems, Science (2022). DOI: 10.1126/science.abh3767. www.science.org/doi/10.1126/science.abh3767

Comment by Dr. Krishna Kumari Challa on April 14, 2022 at 8:57am

The lifespan secret

Ageing is linked to accumulated mutations - according to new research.

Comment by Dr. Krishna Kumari Challa on April 14, 2022 at 8:09am

Keeping web-like NETs from clogging blood vessels could improve stroke outcomes

Preventing the formation of a sticky, web-like substance that can form in blood vessels after a stroke could protect the brain and lead to better outcomes for patients, studies in mice suggest.

Stroke is a leading cause of disability in the world. The most common form, ischemic stroke, occurs when a vessel-blocking clot impedes the flow of blood to the brain. Quick treatment to break up or remove the clot can restore blood flow and limit damage to the brain.

But according to the new study, the blood that comes rushing back carries cells with the potential to cause further harm. Brain damage can worsen even after a clot has been eliminated when immune cells in the blood release sticky webs, known as neutrophil extracellular traps (NETs), that further clog vessels.

Those NETs can gum up the vessels [in the brain] by trapping other cells and reducing the amount of blood flow, causing more brain injury. Markers of NETs correlated with poorer stroke outcomes in patients.

Researchers now found they could prevent these effects in a mouse model of stroke by treating animals with a NET-blocking compound.

Frederik Denorme et al, Neutrophil extracellular traps regulate ischemic stroke brain injury, Journal of Clinical Investigation (2022). DOI: 10.1172/JCI154225

https://medicalxpress.com/news/2022-04-web-like-nets-clogging-blood...

Comment by Dr. Krishna Kumari Challa on April 13, 2022 at 8:31am

New study reveals how to rejuvenate the immune system of elderly people and reduce their risk of infectious disease

A new study identifies a reason for why older adults are significantly more susceptible to infectious diseases than younger people. Study results also pave the way for new potential therapeutic targets to rejuvenate the immune system in older adults and thereby reduce their risk of infectious disease.

T cell immunity declines with aging, thereby increasing severity and mortality from infectious disease. T cells are the quarterback of the immune system and coordinate immune responses to fight off infections. The addition of complex and branched carbohydrate chains ('glycans') to proteins suppresses T cells function.

In this study, researchers show that the branched glycans increase with age in T cells from females more than in males due to age-associated increases in an important sugar metabolite (N-acetylglucosamine) and signaling by the T cell cytokine interleukin-7.

This research reveals that reversing the elevation in branched glycans rejuvenates human and mouse T cell function and reduces severity of Salmonella infection in old female mice.

This suggests several potential novel therapeutic targets to revitalize old T cells, such as altering branched glycans or the age-triggered elevation in serum N-acetylglucosamine and IL-7 signaling.

Haik Mkhikian et al, Age-associated impairment of T cell immunity is linked to sex-dimorphic elevation of N-glycan branching, Nature Aging (2022). DOI: 10.1038/s43587-022-00187-y

https://medicalxpress.com/news/2022-04-reveals-rejuvenate-immune-el...

Comment by Dr. Krishna Kumari Challa on April 12, 2022 at 10:52am

Reductions in PFAS levels from blood or plasma donations may be because PFAS are bound to proteins primarily found in the serum; many other organic pollutants are bound to fats.

The finding that plasma was more effective than blood donation might be because firefighters in the plasma donation group donated blood every six weeks, whereas those in the blood donation group donated every 12 weeks.

In addition, each plasma donation can amount to as much as 800mL compared with 470mL for whole blood.

Plasma PFAS concentrations are also about two times higher than blood PFAS concentrations, which could make plasma donation more efficient at reducing the body burden of PFAS chemicals.

This study provides the first avenue for affected individuals to remove PFAS from their bodies and redress the effects of their PFAS exposure.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2790905

https://theconversation.com/new-evidence-shows-blood-or-plasma-dona...

part 2

Comment by Dr. Krishna Kumari Challa on April 12, 2022 at 10:50am

New evidence shows blood or plasma donations can reduce the PFAS ‘forever chemicals’ in our bodies

You might have heard of PFAS, a synthetic chemical found in certain legacy firefighting foams, non-stick pans, carpets, clothes and stain- or water-resistant materials and paints.

PFAS stands for “per- and poly-fluorinated alkyl substances”. These molecules, made up of chains of carbon and fluorine atoms, are nicknamed “forever chemicals” because they don’t degrade in our bodies.

There is global concern about PFAS because they have been used widely, are persistent in the environment and accumulate in our bodies over time.

There was no way to reduce the amount of PFAS found in the body – until now.

But a new randomised clinical trial, published in the journal JAMA Network Open, has found regularly donating blood or plasma can reduce blood PFAS levels.

The trial involved 285 Fire Rescue Victoria staff and contractors with elevated levels of PFOS, a common detected type of PFAS used in some firefighting foams.

They were randomly allocated to donate plasma every six weeks, to donate whole blood every 12 weeks, or to make no donations (the control group) for 12 months.

Their PFAS levels were measured at four intervals: at recruitment, the start of the trial, after 12 months of following their treatment plan, and again three months later to test if the results were sustained.

Both blood and plasma donation resulted in significantly lower PFAS chemicals than the control group, and these differences were maintained three months later.

Plasma donation was most effective, resulting in a roughly 30% decrease in average blood serum PFAS concentrations over the 12-month trial period.

Part 1

Comment by Dr. Krishna Kumari Challa on April 12, 2022 at 9:19am

Decoy particles trick coronavirus as it evolves

They might look like cells and act like cells. But a new potential COVID-19 treatment is actually a cleverly disguised trickster, which attracts viruses and binds them, rendering them inactive.

As the ever-evolving SARS-CoV-2 virus begins to evade once promising treatments, such as monoclonal antibody therapies, researchers have become more interested in these "decoy" nanoparticles. Mimicking regular cells, decoy nanoparticles soak up viruses like a sponge, inhibiting them from infecting the rest of the body.

In a new study, Northwestern University synthetic biologists set out to elucidate the design rules needed make decoy nanoparticles effective and resistant to viral escape. After designing and testing various iterations, the researchers identified a broad set of decoys—all manufacturable using different methods—that were incredibly effective against the original virus as well as mutant variants.

In fact, decoy nanoparticles were up to 50 times more effective at inhibiting naturally occurring viral mutants, compared to traditional, protein-based inhibitor drugs. When tested against a viral mutant designed to resist such treatments, decoy nanoparticles were up to 1,500 times more effective at inhibiting infection.

Although much more research and clinical evaluations are needed, the researchers believe decoy nanoparticle infusions someday could potentially be used to treat patients with severe or prolonged viral infections.

Taylor F. Gunnels et al, Elucidating Design Principles for Engineering Cell‐Derived Vesicles to Inhibit SARS‐CoV‐2 Infection, Small (2022). DOI: 10.1002/smll.202200125

https://phys.org/news/2022-04-decoy-particles-coronavirus-evolves.h...

Comment by Dr. Krishna Kumari Challa on April 12, 2022 at 8:50am

Climatic variability might not drive evolutionary change as much as previously thought, study finds

A new study combining climate data with fossil records of large mammals that lived across Africa during the last 4 million years casts doubt on a long-standing hypothesis that repeated shifts in climate acted as major drivers of evolutionary change in mammals, including human ancestors.

Published in the journal Proceedings of the National Academy of Sciences, the study yields an African continent-wide synthesis of environmental variability during the Plio-Pleistocene, a period in Earth's history that spans roughly the last 5 million years and includes the last ice age about 20,000 years ago.

The study finds that environmental variability during that time mirrors changes in the Earth's orbit and orientation with respect to the sun, as predicted by a natural phenomenon known as Milankovic cycles. These cycles expose our planet to varying intensity of solar radiation, resulting in well-documented, cyclical effects on Earth's climate at various frequencies.

The researchers observed a long-term trend of increasing environmental variability across Africa attributable to variations in global ice volume and ocean temperature. The results did not, however, yield a significant correlation between environmental variation and rates of species origination or extinction, suggesting that environmental variability and species turnover may not be closely related.

Plio-Pleistocene environmental variability in Africa and its implications for mammalian evolution, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2107393119.

https://phys.org/news/2022-04-climatic-variability-evolutionary-pre...

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