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Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:56am

To understand that critical part of the process, the research team turned to colloidal crystals—particles that are about 10,000 times larger than atoms and spontaneously form a crystal structure at high concentrations. These crystals are used to mimic atomic systems because they have the same structures, undergo the same phase transitions, and possess the same types of defects. Colloidal crystals, however, are very soft—even 100,000 times softer than Jell-O.

The researchers grew these colloidal crystals composed of millions of particles and observed each particle using a confocal optical microscope. When they applied a strain to these crystals, they could measure the motion of each and every particle.

Surprisingly, these colloidal crystals experience significant work hardening—even more strongly than any other material. In fact, when the difference in particle size is taken into account, these ultra-soft materials become much stronger than most metals.
It is the first time that work hardening has been observed in colloidal crystals; it reveals that the process is governed primarily by the geometry of the particles and the defects. The crystals became stronger because of the dislocation defects, how they interact and entangle with one another.

These observations reveal the universal mechanisms of work hardening which will also apply more generally to all materials.

Seongsoo Kim et al, Work hardening in colloidal crystals, Nature (2024). DOI: 10.1038/s41586-024-07453-6

Part 2

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Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:54am

Why do materials get stronger when they are deformed? Research sheds light on universal mechanisms of work hardening

The earliest blacksmiths in the Bronze and Iron Ages figured out that when they deformed metal through bending or hammering, it became stronger. This process, known as work or strain hardening, is still used widely in metallurgy and manufacturing today to increase the strength of everything from car frames to overhead power wires. But materials scientists have never been able to watch this essential process unfold in real time—until now.

A team of scientists  have observed, for the first time, the detailed mechanisms driving the fundamental process of work hardening.

It's been impossible to observe work hardening in metals in real time because the atomic structures can only be observed through an electron microscope. Researchers can compare the structure before and after deformation but have had only a limited view into what happens during the process. Previous research has revealed that imperfections in the structure, known as dislocations, form a network of defects which cause the work hardening.

Part 1

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:35am

Nanoscale silver exhibits intrinsic self-healing abilities without external intervention

As an innovative concept in materials science and engineering, the inspiration for self-healing materials comes from living organisms that have the innate ability to self-heal. Along this line, the search for self-healing materials has been generally focused on "soft" materials like polymers and hydrogels. For solid-state metals, one may intuitively imagine that any form of self-healing will be much more difficult to achieve.

While a few past studies have showcased the self-healing behavior in metals that more or less requires the assistance of external triggers (e.g., by heating, mechanical stimulus, or electron beam irradiation), whether the autonomous self-healing can occur in metal solids without any external intervention remains a scientific curiosity.

Now in a new study published in Matter, researchers from the Institute of Physics (IOP) of the Chinese Academy of Sciences have discovered that such an intrinsic and autonomous self-healing phenomenon can occur in nanoscale silver (Ag).

This study, which combines advanced in-situ transmission electron microscopy (TEM) with molecular dynamics (MD) simulations, reveals that nanoscale Ag can autonomously repair itself from structural damage, such as nanocracks and nanopores, without external intervention.

This remarkable ability is observed not only at room temperature but also at frigid temperatures as low as 173 K. Notably, over the same damaging area, the repeated reversible self-healing cycles can also be achieved with the same level of efficiency.

Jianlin Wang et al, Direct observation of autonomous self-healing in silver, Matter (2024). DOI: 10.1016/j.matt.2024.07.009

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:03am

A patient tests positive for bird flu despite no known exposure to animals

A hospitalized patient in Missouri was infected with bird flu despite having had no known contact with dairy cows or other animals associated with an ongoing outbreak, health officials said last week.

The person tested positive for influenza A, and CDC officials later confirmed it to be bird flu. The person received antiviral medication and has since recovered and gone home, health officials said. It's not clear whether the hospitalization was caused by the bird flu infection or the person's existing health conditions.

The case raises questions about how the person was exposed to the virus. All the previous U.S. infections were among people who worked around cows and poultry.

The investigation is continuing, officials said.

It's the first case detected through routine influenza surveillance rather than through targeted efforts to identify people infected with bird flu through exposure to infected cows and poultry, officials said.

Source: News agencies

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 9:52am

Newly identified biomarkers could reveal risk factors for sudden infant death syndrome

Researchers  are getting closer to being able to predict sudden infant death syndrome, or SIDS.

In a study appearing in JAMA Pediatrics, they have identified signals in the metabolic system of infants who died of SIDS.

This study suggests that metabolic factors may play a crucial role in SIDS. These patterns could help identify children at higher risk, potentially saving lives in the future.

Each year about 1,300 infants under the age of 1 die from SIDS, and researchers still aren't sure what causes these unexpected deaths. What they do know is that there are likely multiple factors that play a role, including inadequate prenatal care, smoking and alcohol use during pregnancy, structural racism and air pollution. Male babies have a higher rate of SIDS than girls.

Researchers are turning to biology to look for a cause of SIDS that can be screened for at birth or targeted with medication. Investigators in this study knew from previous research that the metabolic system—how bodies process and store energy—might play a part in SIDS. They decided to examine the role of the metabolic system more closely, and compare metabolic data taken from infants as part of a routine newborn screening.

They compared the data of infants who eventually died from SIDS with similar infants who lived.

In the 354 infants who died from SIDS, they found that there were some metabolic biomarkers that may be associated with increased risk. For example, infants with lower levels of C-3 and elevated levels of C-14OH appear to have a higher risk of dying from SIDS. These findings are in line with previous research that has found an association between enzymes of fatty acid oxidation, like these, and SIDS.

The scientists also found several other biomarkers that--when elevated--seemed to lead to a reduced risk of SIDS.

JAMA Pediatrics (2024). jamanetwork.com/journals/jamap … pediatrics.2024.3033

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 9:45am

Scientists provided evidence for long-standing wave amplification theory

Physicists  have tested and provided evidence for  a 50-year-old theory for the first time using electro-magnetic waves. They have shown that the energy of waves can be increased by bouncing "twisted waves"—those with angular momentum—off of an object which is rotating in a specific way.

This is known as the "Zel'dovich effect," named after Soviet physicist Yakov Zel'dovich who developed a theory based on this idea in the 1970s. Until now, it was believed to be unobservable with electromagnetic fields.

The Zel'dovich effect works on the principle that waves with angular momentum, that would usually be absorbed by an object, actually become amplified by that object instead, if it is rotating at a fast enough angular velocity. In this case, the object is an aluminum cylinder and it must rotate faster than the frequency of the incoming radiation.

Although physicists successfully tested this theory in sound waves a few years ago, but until this most recent experiment it hadn't been proven with electromagnetic waves. Using relatively simple equipment—a resonant circuit interacting with a spinning metal cylinder—and by creating the specific conditions required, they have now been able to do this.

M. C. Braidotti et al, Amplification of electromagnetic fields by a rotating body, Nature Communications (2024). DOI: 10.1038/s41467-024-49689-w

Comment by Dr. Krishna Kumari Challa on September 9, 2024 at 8:33am

Newly discovered antibody protects against all COVID-19 variants

Researchers have discovered an antibody able to neutralize all known variants of SARS-CoV-2, the virus that causes COVID-19, as well as distantly related SARS-like coronaviruses that infect other animals.

As part of a new study on hybrid immunity to the virus, the large, multi-institution research team discovered and isolated a broadly neutralizing plasma antibody, called SC27, from a single patient. Using technology developed over several years of research into antibody response, the research team obtained the exact molecular sequence of the antibody, opening the possibility of manufacturing it on a larger scale for future treatments.

The discovery of SC27, and other antibodies like it in the future, will help us better protect the population against current and future COVID variants.

Protective antibodies bind to a part of the virus called the spike protein that acts as an anchor point for the virus to attach to and infect the cells in the body. By blocking the spike protein, the antibodies prevent this interaction and, therefore, also prevent infection.

Scientists after verifying  the properties of SC27 found that it recognized the different characteristics of the spike proteins in the many COVID variants.

In addition to the discovery of this antibody, the research found that hybrid immunity—a combination of both infection and vaccination—offers increased antibody-based protection against future exposure compared with infection or vaccination alone.

The researchers have filed a patent application for SC27.

William N. Voss et al, Hybrid immunity to SARS-CoV-2 arises from serological recall of IgG antibodies distinctly imprinted by infection or vaccination, Cell Reports Medicine (2024). DOI: 10.1016/j.xcrm.2024.101668

Comment by Dr. Krishna Kumari Challa on September 9, 2024 at 8:25am

A person's intelligence limits their computer proficiency more than previously thought, say researchers

A new study has found that intelligence, in the form of general cognitive abilities such as perception, thinking and remembering, is more important than hitherto thought at predicting a person's ability to complete common tasks with a PC. The study was published in the International Journal of Human-Computer Studies in August 2024.

This research findings are the first clear proof that cognitive abilities have a significant, independent and wide-ranging effect on people's ability to use a computer. Contrary to what was previously thought, cognitive abilities are as important as previous experience of computer use.

The findings have implications for digital equality, say the researchers, because everyday user interfaces have simply become too complex to use. Practice alone is no longer enough, with intelligence becoming an equally critical factor in predicting performance in computer tasks.

"It is clear that differences between individuals cannot be eliminated simply by means of training; in the future, user interfaces need to be streamlined for simpler use. This age-old goal has been forgotten at some point, and awkwardly designed interfaces have become a driver for the digital divide. We cannot promote a deeper and more equal use of computers in society unless we solve this basic problem, say the researchers. 

However, the research findings also show that age remains the most important factor in how well an individual can use applications. Older people clearly took more time to complete their tasks, and they also felt that the assignments were more burdensome.

 Erik Lintunen et al, Cognitive abilities predict performance in everyday computer tasks, International Journal of Human-Computer Studies (2024). DOI: 10.1016/j.ijhcs.2024.103354

Comment by Dr. Krishna Kumari Challa on September 8, 2024 at 5:07pm

Scientists Discover Mosquitoes Are Using Infrared to Track Humans Down

There's something about us that mosquitoes just love. In addition to our smell, and our breath, our exposed skin acts as a kind of neon sign advertising that this blood bar is open for business.

That's because mosquitoes use infrared sensing in their antennae to track down their prey, a new study has found.
In many parts of the world, mosquito bites are more than an irritation, capable of spreading pathogens like dengue, yellow fever, and Zika virus. Malaria, spread by the Anopheles gambiae mosquito, caused more than 600,000 deaths in 2022, according to World Health Organization statistics.

To avoid serious disease, or even just a case of maddening itchiness, we humans are pretty keen to find ways to prevent mosquito bites.

Research found that mosquitoes use infrared detection – along with other cues we already knew about, like a nose for the CO2 in our breath, and certain body odours, to seek out hosts.

https://www.nature.com/articles/s41586-024-07848-5

Comment by Dr. Krishna Kumari Challa on September 8, 2024 at 4:16pm

Bacteria in your mouth Reproduce in a rare way

The microbial ecosystem nesting in your mouth is giving scientists a rare tool to learn about how bacteria multiply. One of the most common bacteria living in your dental plaque, a filamentous bacterium called Corynebacterium matruchotii, divides not into two daughter cells like most cell divisions but multiple new microbes in a rarer process called multiple fission.

A team of scientists observed single C. matruchotii cells dividing up into up to 14 new cells – a feat that can tell us how these organisms form the scaffolding that supports the hosts of other microbes that are dwelling in your mouth.

The Corynebacterium cells in dental plaque are like a big, bushy tree in the forest; they create a spatial structure that provides the habitat for many other species of bacteria around them.

Most bacteria and archaea reproduce via an asexual process called binary fission. The genetic material divides, and the cell itself then divides, resulting in two organisms where there was one.

Researchers saw the unusual cell division of C. matruchotii was not the normal binary kind, but much more prolific. And it does so in a very strange way.

First, the filament elongates at just one end, growing much longer than the usual size of the cell. It does so at a rate five times faster than other, closely related Corynebacterium species that live in the nose or on the skin.

Then, a number of dividing walls called septa form simultaneously, before the cell breaks apart into between 3 and 14 complete daughter cells.

Thanks to this strange process, a colony of C. matruchotii can grow very fast indeed, up to half a millimeter per day – which might help explain why plaque starts to return to your teeth within hours, no matter how strenuously you clean them.

Another interesting thing about C. matruchotii that might drive its strange growth and division is that it lacks a flagellum; the whip-like appendage other bacteria use to get around. Because it is fixed in place, its fast growth could be a means of exploring its environment and looking for sources of food, the researchers say.

https://www.pnas.org/doi/10.1073/pnas.2408654121

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