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Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 11:38am

Atmospheric microplastic transport predominantly derived from oceans, study finds

Microplastics in our natural environments are of increasing concern as these tiny particles (<5mm diameter) pollute ecosystems, posing issues to the well-being of animals and humans alike. There are two principal categories of microplastics: primary particles are manufactured for their size and originate from consumer products, such as the microbeads used in cosmetics, while secondary microplastics occur due to the breakdown of larger materials, such as plastic water bottles and matter from industrial waste.

This breakdown occurs due to ultraviolet radiation from the sun causing plastic to become brittle and thus susceptible to the erosive action of waves in particular to shear off flakes into the surrounding environment.

Their longevity during decomposition, taking upwards of 500 years to complete in a landfill, is a critical factor of their detrimental impact on habitats. Marine animals ingest microplastics suspended in the ocean, and microplastics mixed with the sand on our beaches is barely noticeable. Research has discovered microplastics in the smallest plankton all the way through to filter feeding giants of the sea—whales.

But it is not just the ocean that transports these tiny particles across the globe. Atmospheric wind regimes can carry microplastics vast distances, and their shape has a critical impact on airborne retention before deposition.

New research published in Nature Geoscience considers a theory-based model to determine the settling velocity (the point at which a particle stops being suspended in air and settles due to gravity) of microplastics of various sizes and shapes (up to 100μm long and down to 2μm wide), as compared to previous research that has assumed spherical microplastics. The effect of air turbulence on settling velocity was also factored to determine long distance transport.

 Shuolin Xiao et al, Long-distance atmospheric transport of microplastic fibres influenced by their shapes, Nature Geoscience (2023). DOI: 10.1038/s41561-023-01264-6

Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 11:33am

Nobel Prize in physics for split-second glimpse of superfast spinning world of electrons

Three scientists won the Nobel Prize in physics on Tuesday for giving us the first split-second glimpse into the superfast world of spinning electrons, a field that could one day lead to better electronics or disease diagnoses.

The award went to French-Swedish physicist Anne L'Huillier, French scientist Pierre Agostini and Hungarian-born Ferenc Krausz for their work with the tiny part of each atom that races around the center and is fundamental to virtually everything: chemistry, physics, our bodies and our gadgets.

Electrons move so fast that they have been out of reach of human efforts to isolate them, but by looking at the tiniest fraction of a second possible, scientists now have a "blurry" glimpse of them and that opens up whole new sciences. 

The electrons are very fast, and the electrons are really the workforce in everywhere. Once you can control and understand electrons, you have taken a very big step forward.

The scientists, who worked separately, used ever-quicker laser pulses to catch the atomic action that happened at such dizzying speeds—one quintillionth of a second, known as an attosecond.

www.nobelprize.org/uploads/202 … physicsprize2023.pdf

Comment by Dr. Krishna Kumari Challa on October 3, 2023 at 11:35am

How muscles change during endurance training

Comment by Dr. Krishna Kumari Challa on October 3, 2023 at 10:45am

The very first beat: How a heart starts to pulse

Comment by Dr. Krishna Kumari Challa on October 3, 2023 at 10:07am

 Scientists find microplastics  in clouds too!

Researchers  have confirmed microplastics are present in clouds, where they are likely affecting the climate in ways that aren't yet fully understood.

In a study published in Environmental Chemistry Letters, scientists climbed Mount Fuji and Mount Oyama in order to collect water from the mists that shroud their peaks, then applied advanced imaging techniques to the samples to determine their physical and chemical properties.

The team identified nine different types of polymers and one type of rubber in the airborne microplastics—ranging in size from 7.1 to 94.6 micrometers.

Each liter of cloud water contained between 6.7 to 13.9 pieces of the plastics.

What's more, "hydrophilic" or water-loving polymers were abundant, suggesting the particles play a significant role in rapid cloud formation and thus climate systems.

"If the issue of 'plastic air pollution' is not addressed proactively, climate change and ecological risks may become a reality, causing irreversible and serious environmental damage in the future," the researchers warned.

When microplastics reach the upper atmosphere and are exposed to ultraviolet radiation from sunlight, they degrade, contributing to greenhouse gasses.

Microplastics—defined as plastic particles under 5 millimeters—come from industrial effluent, textiles, synthetic car tires,  personal care productsand much more.

Yize Wang et al, Airborne hydrophilic microplastics in cloud water at high altitudes and their role in cloud formation, Environmental Chemistry Letters (2023). DOI: 10.1007/s10311-023-01626-x

Comment by Dr. Krishna Kumari Challa on October 3, 2023 at 10:01am

Separating molecules requires a lot of energy. A nanoporous, heat-resistant membrane could change that

Industry has long relied upon energy-intensive processes, such as distillation and crystallization, to separate molecules that ultimately serve as ingredients in medicine, chemicals and other products.

In recent decades, there has been a push to supplant these processes with membranes, which are potentially a lower-cost and eco-friendly alternative. Unfortunately, most membranes are made from polymers that degrade during use, making them impractical.

To solve this problem, a  research team has created a new, sturdier membrane that can withstand harsh environments—high temperatures, high pressure and complex chemical solvents—associated with industrial separation processes.

Made from an inorganic material called carbon-doped metal oxide, it is described in a study published Sept. 7 in Science.

Researchers have developed is a technique to easily fabricate defect-free, strong membranes that have rigid nanopores that can be precisely controlled to allow different-sized molecules to pass through.

To create the membrane, the research team took inspiration from two common, but unrelated, manufacturing techniques.

The first is molecular layer deposition, which involves layering thin films of materials and is most often associated with semiconductor production. The second technique is interfacial polymerization, which is a method of combining chemicals that is commonly used to create fuel cells, chemical sensors and other electronics.

Bratin Sengupta et al, Carbon-doped metal oxide interfacial nanofilms for ultrafast and precise separation of molecules, Science (2023). DOI: 10.1126/science.adh2404

Comment by Dr. Krishna Kumari Challa on October 3, 2023 at 9:47am

Nobel in medicine goes to two scientists whose work enabled creation of mRNA vaccines against COVID-19

Two scientists won the Nobel prize in medicine on Monday for discoveries that enabled the creation of mRNA vaccines against COVID-19 that were critical in slowing the pandemic—technology that's also being studied to fight cancer and other diseases.

Katalin Karikó and Drew Weissman were cited for contributing "to the unprecedented rate of vaccine development during one of the greatest threats to human health," according to the panel that awarded the prize in Stockholm.

The panel said the pair's "groundbreaking findings ... fundamentally changed our understanding of how mRNA interacts with our immune system."

Traditionally, making vaccines required growing viruses or pieces of viruses and then purifying them before next steps. The messenger RNA approach starts with a snippet of genetic code carrying instructions for making proteins. Pick the right virus protein to target, and the body turns into a mini vaccine factory.

But in early experiments with animals, simply injecting lab-grown mRNA triggered a reaction that usually destroyed it. Karikó and Weissman figured out a tiny modification to the building blocks of RNA that made it stealthy enough to slip past immune defenses.

mRNA   vaccine is a "game changer" in shutting down the coronavirus pandemic, crediting the shots with saving millions of lives.

The duo's pivotal mRNA research was combined with two other earlier scientific discoveries to create the COVID-19 vaccines.

www.nobelprize.org/prizes/medi … dvanced-information/

Comment by Dr. Krishna Kumari Challa on September 30, 2023 at 12:53pm

Self-healing of synthetic diamonds observed at room temperature

A team of chemists, materials scientists and aeronautical engineers, reports evidence of self-healing in a sample of synthetic diamond at room temperature.

In their study, reported in the journal Nature Materials, the group created samples of microwire diamonds, caused them to crack and then used an electron microscope to watch them heal. The editors at Nature have also published a Research briefing in the same journal issue outlining the work.

Ever since scientists discovered that diamonds could be made not only in the lab but also in industrial settings, work has been ongoing to find ways to make them less prone to cracking, which limits their use in a wide variety of applications. Prior research has shown that if diamonds are made using a hierarchical internal structure, they become less prone to cracking—but not enough to allow their use in desired applications. More recently, scientists have discovered that nanotwinned diamond composites (ntDC) have some degree of self-healing. But these observations were made with tests conducted at high pressure and temperatures. In this new effort, the research team wondered if similar types of self-healing might be possible at normal pressure and room temperature. To find out, the researchers created several ntDC nanotwinned samples using onion carbon compressed at very high temperatures. They then set up DSC and ntDC nanobeams using an ion beam technique. After mounting ntDC samples, the nanobeams were used to create cracks in the samples, the results of which were viewed using a scanning electron microscope. To ensure their results were reliable, the team conducted multiple fracture tests.

The research team observed self-healing in the ntDC samples. Testing showed the healed samples had a tensile strength of 34%. In studying the healed samples, the researchers found the presence of sp² and sp³-hybridized carbon atoms on opposite sides of cracks, which they describe as osteoblasts; these allowed for healing as they bonded with one another. The team also conducted simulations of what they observed and found that such interactions triggered C-C re-bonding across gaps, allowing healing.

Keliang Qiu et al, Self-healing of fractured diamond, Nature Materials (2023). DOI: 10.1038/s41563-023-01656-4

Fractured diamond can heal itself at room temperature, Nature Materials (2023). DOI: 10.1038/s41563-023-01665-3

Comment by Dr. Krishna Kumari Challa on September 30, 2023 at 9:43am

To figure out why cells have a DNA region that makes cancer worse, the team generated mice without this DNA region, and found these mice do not form a separate passage for air and food in their throat as they develop. Thus, this potentially dangerous cancer-enhancer region is likely in the human genome to regulate airway formation as the human body forms. However, if a developing cancer cell opens this region, it will form a tumor that grows faster and is more dangerous for the patient.

The researchers also found that two proteins known to have a role in the developing airways, FOXA1 and NFIB, are now regulating SOX2 in breast cancer.

The enhancer is activated by the FOXA1 protein and suppressed by the NFIB protein. This means that drugs suppressing FOXA1 or activating NFIB may lead to improved treatments for bladder, uterine, breast and lung cnacer.

Now that scientists know how the SOX2 gene is activated in certain types of cancers, they can look at why this is happening by asking,  "Why did the cancer cells end up on the wrong page of the genome recipe book?"

Luis E Abatti et al, Epigenetic reprogramming of a distal developmental enhancer cluster drives SOX2 overexpression in breast and lung adenocarcinoma, Nucleic Acids Research (2023). DOI: 10.1093/nar/gkad734

Part 2

Comment by Dr. Krishna Kumari Challa on September 30, 2023 at 9:40am

Researchers find a cancer enhancer in the genome that drives tumor cell growth

Researchers have found that cancer cells can enhance tumor growth by hijacking enhancer DNA normally used when tissues and organs are formed. The mechanism, called enhancer reprogramming, occurs in bladder, uterine, breast and lung cancer, and could cause these types of tumors to grow faster in patients.

The results also pinpoint the role that specific proteins play in regulating the enhancer region which may lead to improved treatments for these cancer types. Living cells, even cancer cells, follow instructions in the genome to turn genes on and off in different contexts. The genome is like a recipe book written in DNA that gives instructions on making all the parts of the body. In each organ, only the recipes relevant to that organ should be followed, whether it's the instructions for lung, breast or some other tissue. Like flipping pages in a recipe book, the DNA containing the instructions for turning genes on in the lung is open and used in the lung, for example, but closed and ignored in other types of cells.

Scientists know that some cancer cells are opening the wrong pages in the recipe book—ones that contain the SOX2 gene, which can cause tumours to grow uncontrollably. They wanted to find out: how does the gene become expressed in cancer cells?

The researchers analyzed genome data to look for enhancer DNA that could activate SOX2 in cancer cells. The enhancer they found is open in many different types of patient tumors, meaning this could be a cancer enhancer active in bladder, uterus, breast and lung tumors. Unlike many cancer-causing changes, this enhancer reprogramming mechanism does not arise out of mutation due to DNA damage; it is caused by part of the genome opening when it should be staying closed.

The researchers then determined that the enhancer causes increased cancer cell growth because when they removed the enhancer in lab-grown cells, the cancer cells created fewer new tumour colonies.

Part 1

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