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Comment by Dr. Krishna Kumari Challa on December 21, 2023 at 11:23am

Researchers demonstrate how magnetism can be actively changed by pressure

Magnetism occurs depending on how electrons behave. For example, the elementary particles can generate an electric current with their charge and thereby induce a magnetic field. However, magnetism can also arise through the collective alignment of the magnetic moments (spins) in a material. What has not been possible until now, however, is to continuously change the type of magnetism in a crystal.

An international research team has now succeeded in doing just that: Changing magnetism  "by pushing a button." For that, the team continuously changed the magnetic interactions in a single crystal by applying pressure. The researchers recently published their results in Physical Review Letters.

Spins can be visualized as small compass needles that can align themselves in an external magnetic field and have a magnetic field themselves. In case of ferromagnetism, which is used in permanent magnets, all electron spins align parallel to each other. In some arrangements of electron spins, for example in ordinary square, checkerboard-type crystal lattices, an anti-parallel alignment of the spins is also possible: Neighboring spins always point alternately in opposite directions.

With triangular lattices (or lattices in which triangular structures occur, such as the more complex kagome lattice), a completely antiparallel arrangement is not possible: If two corners of a triangle have opposite spin directions, the remaining side must match one of the two directions. Both options—spin up or spin down—are then exactly equivalent. "This possibility of multiple identical alternatives is known as 'geometrical frustration' and occurs in crystal structures with electron spins arranged in triangular, kagome or honeycomb lattices.

The remaining unpaired magnetic moments could be entangled with each other, manipulated with external magnetic fields and thus used for data storage or computational operations in quantum computers.

In real materials, we are still far from such a state of ideal frustration. First of all, we need to be able to precisely control the symmetry of the crystal lattice and thus the magnetic properties

Part 1

Comment by Dr. Krishna Kumari Challa on December 21, 2023 at 11:17am

Study details how biomimetic nanomaterials can minimize damage after a heart attack

A recent study details how, when targeted specifically to the spleen, histone deacetylase (HDAC) inhibitors, chemical compounds that can be used to treat cancers and other diseases, can potentially improve the healing response following a heart attack.

Normally, immune cells  migrate from the spleen to the heart after a heart attack in response to injury. Here, researchers found that they could design nanomaterials that mimic dead and dying red blood cells, causing them to be retained in the spleen and enabling them to deliver inhibitors that modulate the inflammatory response.

Notably, this targeting strategy significantly decreases cardiac scar size and the preservation of heart function, even after just one dose, when given within two hours of heart attack injury.

 Rajendran JC Bose et al, Biomimetic Nanomaterials for the Immunomodulation of the Cardiosplenic Axis Postmyocardial Infarction, Advanced Materials (2023). DOI: 10.1002/adma.202304615

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Mineral coatings could enable shelf-stable mRNA therapies

A protective mineral coating identified by University of Wisconsin–Madison biomedical engineering researchers could allow powerful messenger RNA therapeutics like COVID-19 vaccines to be stored at room temperature, making them more accessible to lower-resourced communities across the world.

Comment by Dr. Krishna Kumari Challa on December 21, 2023 at 11:13am

Why paint does not dry slower in a humid environment

A team of physicists  working with an infection and immunity specialist  has, via experimentation, validated a theory to explain why paint dries at the same rate regardless of humidity levels. The study is published in Physical Review Letters.

Common sense suggests that paint should dry faster on an outdoor fence on a dry day than when it is humid because evaporation occurs faster when the air around a liquid source is drier. But anecdotal evidence suggests this is not the case for paint and other liquids. Six years ago, chemists developed a theory to explain why this is the case. They suggested it is because large molecules in the liquid are pulled to the surface during evaporation, forming a 'polarization layer' that inhibits evaporation, and by extension, drying. In this new effort, the research team conducted an experiment to test this theory.

The researchers found that in their experiments evaporation rates remained constant for approximately three hours. But then, rates plummeted, as was theorized by chemists, regardless of humidity levels. The evaporation rate did not decrease as humidity increased during the initial three hours. However, the theory only appeared to hold for humidity levels up to 80%—at rates higher than that, evaporation did slow down, which the team suggests was likely due to some other force.

The researchers suggest their work could have medical applications as recent research efforts have shown that respiratory droplets tend to form skins similar to those seen in the experimental apparatus.

Max Huisman et al, Evaporation of Concentrated Polymer Solutions Is Insensitive to Relative Humidity, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.131.248102

Comment by Dr. Krishna Kumari Challa on December 21, 2023 at 9:54am

Using AI, researchers identify a new class of antibiotic candidates that can kill a drug-resistant bacterium

Using a type of artificial intelligence known as deep learning, researchers have discovered a class of compounds that can kill a drug-resistant bacterium that causes thousands of deaths around the world every year.

In a  study  appearing in Nature, the researchers showed that these compounds could kill methicillin-resistant Staphylococcus aureus (MRSA) grown in a lab dish and in two mouse models of MRSA infection. The compounds also show very low toxicity against human cells, making them particularly good drug candidates. A key innovation of the new study is that the researchers were also able to figure out what kinds of information the deep-learning model was using to make its antibiotic potency predictions. This knowledge could help researchers to design additional drugs that might work even better than the ones identified by the model.

James Collins, Discovery of a structural class of antibiotics with explainable deep learning, Nature (2023). DOI: 10.1038/s41586-023-06887-8. www.nature.com/articles/s41586-023-06887-8

Comment by Dr. Krishna Kumari Challa on December 20, 2023 at 10:53am

Flu has long-term illness risk — like COVID

People who have been very ill with flu could develop a long-haul illness similar to long COVID. The medical records of more than 81,000 people who were hospitalized with COVID-19 and almost 11,000 with flu show that both infections carried a risk of health problems in the following .... ‘Long flu’ symptoms were more likely to be respiratory — shortness of breath or cough. We need to “stop trivialising viral infections and understand that they are major drivers of chronic diseases”, says clinical epidemiologist and study co-author Ziyad Al-Aly.

Reference: The Lancet Infectious Diseases paper

Comment by Dr. Krishna Kumari Challa on December 20, 2023 at 10:50am

What we can expect in the year 2024 in the field of science

The consciousness debate: round two

Next year could bring new insights into the neural basis of consciousness. A large project that is testing two theories of consciousness through a series of adversarial experiments is expected to release the results of its second experiment by the end of 2024. In the first round, both theories failed to completely align with observed brain-imaging data, settling a 25-year bet in favour of philosophy over neuroscience. The second round could put neuroscience closer to deciphering the mysteries of the subjective experience.

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Saving the planet

In the second half of 2024, the International Court of Justice in the Hague could give an opinion on nations’ legal obligations to combat climate change, and rule on legal consequences for those deemed to be damaging the climate. Although the ruling will not be legally binding, the court’s clout can push countries to strengthen their climate goals and can be cited in domestic legal cases.

Negotiations for the UN plastics treaty, which seeks to establish a binding international agreement to eliminate plastic pollution, will wrap up next year. Since the 1950s, the world has produced 10 billion tonnes of plastic, of which more than 7 billion tonnes is now waste — much of which is polluting oceans and harming wildlife. But there is growing concern among researchers that the UN negotiations, which started last year, are advancing too slowly and will not accomplish the intended goals.

https://www.nature.com/articles/d41586-023-04044-9?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on December 20, 2023 at 10:49am

Weaponized mosquitoes

The World Mosquito Program will start producing disease-fighting mosquitoes at a factory in Brazil next year. The mosquitos are infected by a bacterial strain that prevents them from transmitting pathogenic viruses, and could protect up to 70 million people from diseases such as dengue and zika. The non-profit organization will produce up to five billion bacteria-infected mosquitoes per year over the next decade.

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Illuminating dark matter

Results of an experiment to detect dark-matter particles known as axions will see light in 2024. Axions are thought to be emitted by the Sun and converted into light, but the tiny particles have not yet been observed experimentally because they require sensitive detection tools and an extremely strong magnetic field. The experiment BabyIAXO at the German Electron Synchrotron in Hamburg is using a solar telescope made of a 10-metre-long magnet and ultra-sensitive noise-free X-ray detectors to track the centre of the Sun for 12 hours per day, to capture the conversion of axions into photons.

And 2024 could be the year that scientists nail down the mass of the neutrino — the most mysterious particle in the standard model of particle physics. Results of the Karlsruhe Tritium Neutrino experiment in 2022 showed that neutrinos had a maximum mass of 0.8 electron volts. Researchers will finish collecting data in 2024 and are expected to make a definite measurement of the tiny particles.

Comment by Dr. Krishna Kumari Challa on December 20, 2023 at 10:24am

The research team explained that they suggest this path because other studies have shown women to be very responsive to exercise countermeasures during (simulated) weightlessness. In addition, future space missions are likely to be much longer than the current study and information in this area is needed for longer durations of weightlessness.

More information: Todd A. Trappe et al, Microgravity-induced skeletal muscle atrophy in women and men: implications for long-duration spaceflights to the Moon and Mars, Journal of Applied Physiology (2023). DOI: 10.1152/japplphysiol.00412.2023

Part 2

Comment by Dr. Krishna Kumari Challa on December 20, 2023 at 10:24am

Research suggests women lose more muscle than men in spaceflight

New research published ahead of print in the Journal of Applied Physiology suggests women lose more muscle than men in a microgravity environment such as spaceflight. The study "represent[s] the longest bed rest study on a large cohort of women" and underscores the need for more sex-specific studies on physiological responses to microgravity, the research team wrote.

Historically, only about 2 out of every 10 astronauts sent into space have been women. With NASA's decision to diversify crewmembers in future spaceflight missions, including the agency's intention to send the first woman to the moon in 2024, scientists are more interested than ever in discovering how biological sex plays a role in the physiological response to microgravity. However, existing literature on the female response to low-gravity environments is sparse.

The current study explored muscle loss (atrophy) in men and women during two extended bed rest trials. The men spent 90 days, and the women spent 60 days in a 6-degree head-down tilt position, where their head was below their feet. This simulated a weightless condition similar to what crewmembers experience during spaceflight. Both volunteer groups ate, slept, performed personal hygiene, and all other activities in either the head-down tilt or a horizontal position.

The research team conducted magnetic resonance imaging tests on the volunteers' thigh and calf muscles before and after the trial as well as at the one-month mark of bed rest. These muscles were chosen "because they are critical for ambulation and extravehicular activities that likely will be required of space crews visiting the moon or Mars," the researchers said.

The researchers found that all participants lost a significant amount of muscle mass in both areas of the leg throughout their bed rest period compared to before bed rest. The women lost more muscle from the quadriceps at one month compared to the men, and the women lost more muscle mass at two months than the men lost at three months. This trend is concerning not only because of the impact on typical muscle function but also because "it is now established that muscle serves as an endocrine organ, communicating with numerous other organs," the research team explained.

The current findings from two spaceflight simulation studies suggest that women are more susceptible to weightlessness-induced muscle atrophy," the researchers wrote. "Therefore, a more appropriate path to understand sex-specific responses to microgravity (including the muscle atrophy issue) and to obtain data to better protect the health of future crewmembers may be through well-controlled long-duration bed rest studies with only exercise countermeasure groups."

Part 1

Comment by Dr. Krishna Kumari Challa on December 20, 2023 at 9:59am

Scientists construct a synthetic yeast genome

Chromosomes are long DNA molecules that collectively form a genome, containing all the genetic material of an organism. Advances in technology have allowed scientists to redesign and construct different chromosomal sequences, facilitating the study of the link between gene variations and traits.

Notably, yeast is an important model organism for the understanding of basic cellular processes, owing to its similarity to plants and animals at the cellular level while being considerably simpler to manipulate and study. Therefore, redesigning and synthesizing a yeast genome can help scientists to understand the impact of genetic variations on individual traits, potentially elucidating the mechanisms of genetic diseases.

With this goal in mind, scientists 

have synthesized a redesigned yeast—chromosome XV, that comprises 1.05 million base pairs—the largest synthesized chromosome in Asia.

The work is published in Cell Genomics. It is seen as a major milestone in the field of synthetic biology. 

In creating the synthetic Chromosome XV (synXV), the Medicine team extensively redesigned the original DNA to incorporate various changes that resulted in a sequence which is distinctively unique and different from the natural one.

In order to streamline the assembly process of synXV, the team developed a groundbreaking technology, called CRISPR/Cas9-mediated mitotic recombination with endoreduplication (CRIMiRE). This innovative technology significantly speeds up the exchange of large chromosomal DNA segments at specific sites, hence enabling multiple synthetic chromosome segments to be assembled concurrently and stitched together into a complete synthetic Chromosome XV.

Upon generating the synthetic yeast chromosome, CRIMiRE further allows for the intentional mixing and matching of synXV with another yeast chromosome. This generates different genetic combinations for studies, which illuminates the association between genetic variations and individual traits.

Given the challenges of working with extremely long DNA sequences, the traditional approaches are unable to change the sequences efficiently. However, the use of CRIMiRE has simplified the process, shortening it tenfold, potentially revolutionizing the way larger synthetic chromosomes are built for more complex organisms. This achievement opens the door to understanding basic questions about biological processes.

 Jee Loon Foo et al, Establishing chromosomal design-build-test-learn through a synthetic chromosome and its combinatorial reconfiguration, Cell Genomics (2023). DOI: 10.1016/j.xgen.2023.100435

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