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Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 12:19pm

WHO redefines airborne transmission

The World Health Organization (WHO) has changed how it classifies airborne pathogens. It has removed the distinction between transmission by smaller virus-containing ‘aerosol’ particles and spread through larger ‘droplets’. The division, which some researchers argue was unscientific, justified WHO’s March 2020 assertion that SARS-CoV-2, the virus behind the COVID-19 pandemic, was not airborne. Under the new definition, SARS-CoV-2 would be recognized as spreading ‘through the air’ — although some scientists feel this term is less clear than ‘airborne’. “I'm not saying everybody is happy, and not everybody agrees on every word in the document, but at least people have agreed this is a baseline terminology,” says WHO chief scientist Jeremy Farrar.

https://www.who.int/publications/m/item/global-technical-consultati...

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 12:17pm

Lethal mpox strain appears to spread via sex
A virulent strain of the monkeypox virus might have gained the ability to spread through sexual contact. The strain, called clade Ib, has caused a cluster of infections in a conflict-ridden region of the Democratic Republic of the Congo (DRC). This isn’t the first time scientists have warned that the monkeypox virus could become sexually transmissible: similar warnings during a 2017 outbreak in Nigeria were largely ignored. The strain responsible, clade II, is less lethal than clade Ib, but ultimately caused an ongoing global outbreak that has infected more than 94,000 people and killed more than 180.

https://www.medrxiv.org/content/10.1101/2024.04.12.24305195v2.full....

https://www.nature.com/articles/d41586-024-01167-5?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 12:14pm

Scientists study lipids cell by cell, making new cancer research possible

Imagine being able to look inside a single cancer cell and see how it communicates with its neighbors. Scientists are celebrating a new technique that lets them study the fatty contents of cancer cells, one by one.

A study has sampled single live cancer cells and measured the fatty lipid compounds inside them. Working with partners at GSK and UCL, and developing new equipment with Yokogawa, the team saw how those cells transformed in response to changes in their environment.
The work appears in Analytical Chemistry.
The trouble with cancer cells is that no two are alike. That makes it harder to design good treatment, because some cells will always resist treatment more than others. Yet it has always proven tricky to study live cells after they have been removed from their natural environment, in enough detail to truly understand their makeup. That is why it is so exciting to be able to sample live cells under a microscope and study their fatty contents one by one.
Individual pancreatic cancer cells were lifted from a glass culture dish using Yokogawa's Single Cellome System SS2000. This extracts single live cells using tiny tubes 10 µm across—about half the diameter of the thinnest human hair.

By staining the cells with fluorescent dye, the researchers could monitor lipid droplets (stores of fatty molecules inside cells, thought to play an important role in cancer) throughout the experiment.

Then, working with partners at Sciex, researchers developed a new method using a mass spectrometer to fragment the lipids in the cells. This told them about their composition.

The researchers demonstrated that different cells had very different lipid profiles. They also saw how lipids in the cells changed in response to what was going on around them.

Untargeted single-cell lipidomics using liquid chromatography and data-dependent acquisition after live cell selection, Analytical Chemistry (2024). DOI: 10.1021/acs.analchem.3c05677

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 11:35am

Octocorals are one of the oldest groups of animals on the planet known to bioluminescence. "So, the question 's when did they develop this ability?"
Researchers had completed an extremely detailed, well-supported evolutionary tree of the octocorals in 2022. They created this map of evolutionary relationships, or phylogeny, using genetic data from 185 species of octocorals.

With this evolutionary tree grounded in genetic evidence, DeLeo and Quattrini then situated two octocoral fossils of known ages within the tree according to their physical features. The scientists were able to use the fossils' ages and their respective positions in the octocoral evolutionary tree to date to figure out roughly when octocoral lineages split apart to become two or more branches.

Next, the team mapped out the branches of the phylogeny that featured living bioluminescent species.

With the evolutionary tree dated and the branches that contained luminous species labeled, the team then used a series of statistical techniques to perform an analysis called ancestral state reconstruction.
If we know these species of octocorals living today are bioluminescent, we can use statistics to infer whether their ancestors were highly probable to be bioluminescent or not. The more living species with the shared trait, the higher the probability that as you move back in time that those ancestors likely had that trait as well.
The researchers used numerous different statistical methods for their ancestral state reconstruction, but all arrived at the same result: Some 540 million years ago, the common ancestor of all octocorals were very likely bioluminescent. That is 273 million years earlier than the glowing ostracod crustaceans that previously held the title of earliest evolution of bioluminescence in animals.
The octocorals' thousands of living representatives and relatively high incidence of bioluminescence suggests the trait has played a role in the group's evolutionary success. While this further begs the question of what exactly octocorals are using bioluminescence for, the researchers said the fact that it has been retained for so long highlights how important this form of communication has become for their fitness and survival.

Evolution of bioluminescence in Anthozoa with emphasis on Octocorallia, Proceedings of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rspb.2023.2626. royalsocietypublishing.org/doi … .1098/rspb.2023.2626

Part 2

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 11:31am

Bioluminescence first evolved in animals at least 540 million years ago, pushing back previous oldest dated example

Bioluminescence first evolved in animals at least 540 million years ago in a group of marine invertebrates called octocorals, according to the results of a new study from scientists with the Smithsonian's National Museum of Natural History.

The results, published April 23, in the Proceedings of the Royal Society B: Biological Sciences, push back the previous record for the luminous trait's oldest dated emergence in animals by nearly 300 million years, and could one day help scientists decode why the ability to produce light evolved in the first place.

Bioluminescence—the ability of living things to produce light via chemical reactions—has independently evolved at least 94 times in nature and is involved in a huge range of behaviors including camouflage, courtship, communication and hunting. Until now, the earliest dated origin of bioluminescence in animals was thought to be around 267 million years ago in small marine crustaceans called ostracods.
But for a trait that is literally illuminating, bioluminescence's origins have remained shadowy.

Nobody quite knows why it first evolved in animals.
In search of the trait's earliest origins, the researchers decided to peer back into the evolutionary history of the octocorals, an evolutionarily ancient and frequently bioluminescent group of animals that includes soft corals, sea fans and sea pens.

Like hard corals, octocorals are tiny colonial polyps that secrete a framework that becomes their refuge, but unlike their stony relatives, that structure is usually soft. Octocorals that glow typically only do so when bumped or otherwise disturbed, leaving the precise function of their ability to produce light a bit mysterious.
Part 1

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 11:05am

In a collaboration with Kobus Kuipers of Delft University of Technology, the group indeed demonstrated a similar effect for light in a photonic crystal.

A photonic crystal normally consists of a regular—two dimensional—pattern of holes in a silicon layer. Light can move freely in this material, just like electrons in graphene.
Breaking this regularity in exactly the right manner will deform the array and consequently lock the photons. This is how they create Landau levels for photons.
In Landau levels light waves no longer move; they do not flow through the crystal but stand still. The researchers succeeded in demonstrating this, showing that the deformation of the crystal array has a similar effect on photons as a magnetic field on electrons.

By playing with the deformation pattern, we even managed to establish various types of effective magnetic fields in one material. As a result, photons can move through certain parts of the material but not in others. Hence, these insights also provide new ways to steer light on a chip.
This brings on-chip applications closer.If we can confine light at the nanoscale and bring it to a halt like this, its strength will be enhanced tremendously. And not only at one location, but over the entire crystal surface. Such light concentration is very important in nanophotonic devices, for example for the development of efficient lasers or quantum light sources.

René Barczyk et al, Observation of Landau levels and chiral edge states in photonic crystals through pseudomagnetic fields induced by synthetic strain, Nature Photonics (2024). DOI: 10.1038/s41566-024-01412-3

Part 2

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 11:02am

Light stands still in a deformed crystal

 AMOLF researchers, in collaboration with Delft University of Technology have succeeded in bringing light waves to a halt by deforming the two-dimensional photonic crystal that contains them. The researchers show that even a subtle deformation can have a substantial effect on photons in the crystal. This resembles the effect that a magnetic field has on electrons.

This principle offers a new approach to slow down light fields and thereby enhance their strength. Realizing this on a chip is particularly important for many applications, say the researchers.

The researchers have published their findings in the journal Nature Photonics. Simultaneously, a research team from Pennsylvania State University has published an article in the same journal about how they demonstrated—independently from the Dutch team—an identical effect.

Manipulating the flow of light in a material at small scales is beneficial for the development of nanophotonic chips. For electrons, such manipulation can be realized using magnetic fields; the Lorentz force steers the motion of electrons. However, this is impossible for photons because they do not have charge.

Researchers in the Photonic Forces group at AMOLF are looking for techniques and materials that would enable them to apply forces to photons that resemble the effects of magnetic fields.

The researchers looked for inspiration at the way in which electrons behave in materials. In a conductor, electrons can in principle move freely, but an external magnetic field can stop this. The circular movement caused by the magnetic field stops conduction and as such electrons can only exist in the material if they have very specific energies. These energy levels are called Landau levels, and they are characteristic for electrons in a magnetic field  

But, in the two-dimensional material graphene—that consists of a single layer of carbon atoms arranged in a crystal—these Landau levels can also be caused by a different mechanism than a magnetic field. In general, graphene is a good electronic conductor, but this changes when the crystal array is deformed, for instance by stretching it like elastics.

"Such mechanical deformation stops conduction; the material turns into an insulator and consequently the electrons are bound to Landau levels. Hence, the deformation of graphene has a similar effect on electrons in a material as a magnetic field, even without a magnet. Researchers asked themselves if a similar approach would also work for photons."
Part 1

Comment by Dr. Krishna Kumari Challa on April 24, 2024 at 11:51am

The authors tested variations of a fast-pulsing laser treatment to achieve the optimal balance of characteristics in the cork that can be achieved at low cost.

They closely examined nanoscopic structural changes and measured the ratio of oxygen and carbon in the material, changes in the angles with which water and oil contact the surface, and the material's light wave absorption, reflection, and emission across the spectrum to determine its durability after multiple cycles of warming and cooling.

The photothermal properties endowed in cork through this laser processing allow the cork to warm quickly in the sun. The deep grooves also increase the surface area exposed to sunlight, so the cork can be warmed by just a little sunlight in 10–15 seconds. This energy is used to heat up spilled oil, lowering its viscosity and making it easier to collect. In experiments, the laser-treated cork collected oil out of water within two minutes.

The laser treatments not only help to better absorb oil, but also work to keep water out.
When the cork undergoes a fast-pulsing laser treatment, its surface microstructure becomes rougher. This micro- to nano-level roughness enhances hydrophobicity.

As a result, the cork collects the oil without absorbing water, so the oil can be extracted from the cork and possibly even reused.

Femtosecond laser structured black superhydrophobic cork for efficient solar-driven cleanup of crude oil, Applied Physics Letters (2024). DOI: 10.1063/5.0199291

Part 2

Comment by Dr. Krishna Kumari Challa on April 24, 2024 at 11:50am

Laser-treated cork absorbs oil for carbon-neutral ocean cleanup

Oil spills are deadly disasters for ocean ecosystems. They can have lasting impacts on fish and marine mammals for decades and wreak havoc on coastal forests, coral reefs, and the surrounding land. Chemical dispersants are often used to break down oil, but they often increase toxicity in the process.

In Applied Physics Letters, researchers  published their work using laser treatments to transform ordinary cork  into a powerful tool for treating oil spills.

They wanted to create a nontoxic, effective oil cleanup solution using materials with a low carbon footprint, but their decision to try cork resulted from a surprising discovery.

In a different laser experiment, they accidentally found that the wettability of the cork processed using a laser changed significantly, gaining superhydrophobic (water-repelling) and superoleophilic (oil-attracting) properties. After appropriately adjusting the processing parameters, the surface of the cork became very dark, which made them realize that it might be an excellent material for photothermal conversion.

Combining these results with the eco-friendly, recyclable advantages of cork, they thought of using it for marine oil spill cleanup.

Cork comes from the bark of cork oak trees, which can live for hundreds of years. These trees can be harvested about every seven years, making cork a renewable material. When the bark is removed, the trees amplify their biological activity to replace it and increase their carbon storage, so harvesting cork helps mitigate carbon emissions. Part 1

Comment by Dr. Krishna Kumari Challa on April 24, 2024 at 11:00am

Researchers detect a new molecule in space

New research has revealed the presence of a previously unknown molecule in space. The open-access paper describing it, "Rotational Spectrum and First Interstellar Detection of 2-Methoxyethanol Using ALMA Observations of NGC 6334I," was published in the April 12 issue of The Astrophysical Journal Letters.

Researchers worked to assemble a puzzle comprised of pieces collected from across the globe, extending beyond MIT to France, Florida, Virginia, and Copenhagen, to achieve this exciting discovery.

To detect new molecules in space, researchers first must have an idea of what molecule they want to look for, then they can record its spectrum in the lab here on Earth, and then finally they look for that spectrum in space using telescopes.

To detect this molecule using radio telescope observations, the group first needed to measure and analyze its rotational spectrum on Earth. The researchers combined experiments from the University of Lille (Lille, France), the New College of Florida (Sarasota, Florida), and the McGuire lab at MIT to measure this spectrum over a broadband region of frequencies ranging from the microwave to sub-millimeter wave regimes (approximately 8 to 500 gigahertz).

The data gleaned from these measurements permitted a search for the molecule using Atacama Large Millimeter/submillimeter Array (ALMA) observations toward two separate star-forming regions: NGC 6334I and IRAS 16293-2422B. Members of the group analyzed these telescope observations alongside researchers at the National Radio Astronomy Observatory (Charlottesville, Virginia) and the University of Copenhagen, Denmark.

Ultimately, they observed 25 rotational lines of 2-methoxyethanol that lined up with the molecular signal observed toward NGC 6334I (the barcode matched), thus resulting in a secure detection of 2-methoxyethanol in this source.This allowed them to then derive physical parameters of the molecule toward NGC 6334I, such as its abundance and excitation temperature. It also enabled an investigation of the possible chemical formation pathways from known interstellar precursors.
Molecular discoveries like this one help the researchers to better understand the development of molecular complexity in space during the star formation process. 2-methoxyethanol, which contains 13 atoms, is quite large for interstellar standards—as of 2021, only six species larger than 13 atoms were detected outside the solar system, many by this research group, and all of them existing as ringed structures.
Continued observations of large molecules and subsequent derivations of their abundances allows scientists to advance our knowledge of how efficiently large molecules can form and by which specific reactions they may be produced.

Zachary T. P. Fried et al, Rotational Spectrum and First Interstellar Detection of 2-methoxyethanol Using ALMA Observations of NGC 6334I, The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad37ff

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