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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

Comment by Dr. Krishna Kumari Challa on September 30, 2023 at 9:24am

Scientists zero in on the life-threatening fungus, Candida auris' ability to stick

In 2009, a mysterious fungus emerged seemingly from out of thin air, targeting the most vulnerable among us. The fungus in question poses a very real threat. Scientists are trying to figure out what makes the life-threatening fungus Candida auris tick—and why even the best infection control protocols in hospitals and other care settings often fail to get rid of it.

Researchers have now zeroed in on C. auris' uncanny ability to stick to everything from skin to catheters and made a startling discovery.

They discovered that C. auris is unlike any other known fungus in that it employs a type of protein, called an adhesin, that acts very similar to those used by oceanic organisms, such as barnacles and mollusks.

The new adhesin is only present in C. auris so we don't know where it came from evolutionarily. It doesn't look like it came from any other organisms by sequence similarity. The bonds formed by Scf1, they revealed, are cation-pi bonds, which are among the strongest non-covalent chemical bonds in nature.

Furthermore, the team discovered that SCF1 was associated with increased colonization and an enhanced ability to cause disease. Using mouse models, they demonstrated that a loss of both SCF1 and IFF4109 diminished the ability of a strain of C. auris to colonize skin and an in-dwelling catheter. What's more, strains designed to over express SCF1 saw enhanced virulence and more fungal lesions.

It could be that adhesin is required to get attached to blood vessels,  or maybe it changes the host-receptor interactions which has been true for the related fungus Candida albicans, but we don't know in this case yet.

Darian J. Santana et al, A Candida auris –specific adhesin, Scf1 , governs surface association, colonization, and virulence, Science (2023). DOI: 10.1126/science.adf8972

Comment by Dr. Krishna Kumari Challa on September 29, 2023 at 9:12am

Fire- safe fuel!

 Chemical engineers have designed a fuel that ignites only with the application of electric current. Since it doesn't react to flames and cannot start accidental fires during storage or transport, it is a "safe" liquid fuel.

The fuel we're normally using is not very safe. It evaporates and could ignite, and it's difficult to stop that. 

It is much easier to control the flammability of our fuel and stop it from burning when we remove voltage.

When fuel combusts, it is not the liquid itself that burns. Instead, it is the volatile fuel molecules hovering above the liquid that ignite on contact with oxygen and flame. Removing an oxygen source will extinguish the flame, but this is difficult to do outside of an engine.

If you throw a match into a pool of gasoline on the ground, it's the vapor of the gas that's burning. You can smell that vapor and you instantly know it's volatile. If you can control the vapour, you can control whether the fuel burns.

The base of the new fuel is an ionic liquid, which is a form of liquified salt. It is similar to the salt we use to flavour food, which is sodium chloride. The one researchers used for this project has a lower melting point than table salt, low vapour pressure, and is organic.

Once in the lab, the research team modified the ionic liquid's formula, replacing the chlorine with perchlorate. Then, they used a cigarette lighter to see if the resulting liquid would burn. 

Next the team tried an application of voltage followed by a lighter flame, which did ignite. Once they shut off the current, the flame was gone, and they were able to repeat that process over and over again—applying voltage, seeing smoke, lighting the smoke so it burned, then turning it off. It's a system they could start and stop very quickly.

Adding more voltage to the liquid resulted in larger flames with more energy output. As such the approach could also act like a metering or throttling system in an engine.

Prithwish Biswas et al, Electrochemical Modulation of the Flammability of Ionic Liquid Fuels, Journal of the American Chemical Society (2023). DOI: 10.1021/jacs.3c04820

Comment by Dr. Krishna Kumari Challa on September 29, 2023 at 8:24am

Recessive genes make the carrot colour orange

A new study of the genetic blueprints of more than 600 types of carrot shows that three specific genes are required to give carrots an orange color. Surprisingly, these three required genes all need to be recessive, or turned off. The paper's findings shed light on the traits important to carrot improvement efforts and could lead to better health benefits from the vegetable.

Normally, to make some function, you need genes to be turned on. In the case of the orange carrot, the genes that regulate orange carotenoids—the precursor of vitamin A that have been shown to provide health benefits—need to be turned off.

According to the researchers, orange carrot could have resulted from white and yellow carrot crosses, as white and yellow carrots are at the base of the phylogenetic tree for the orange carrot. Also, carotenoids got their name because they were first isolated from carrots.

Population genomics identifies genetic signatures of carrot domestication and improvement and uncovers the origin of high carotenoid orange carrots, Nature Plants (2023). DOI: 10.1038/s41477-023-01526-6

Comment by Dr. Krishna Kumari Challa on September 29, 2023 at 8:03am

An adhesive and stretchable epicardial patch to precisely monitor the heart's activity

Epicardial patches are carefully engineered tissue patches that can be placed near or on a patient's heart. These devices can help doctors to diagnose and treat a variety of heart conditions, including arrhythmia and heart attacks (i.e., myocardial infarctions).

In recent years, several engineers and medical researchers have been trying to develop these devices, yet many solutions proposed so far are not ideal. Specifically, most epicardial patches created so far are designed to be affixed onto the heart via a medical procedure known as "suturing," which can be both challenging and risky. Researchers recently developed an alternative epicardial patch that could be much easier to apply in clinical settings. This patch, introduced in Nature Electronics, is both stretchable and adhesive; thus, it does not need to be affixed onto a patient's heart through the suturing process.

Considering the highly irregular surface of the heart, the existing devices with low adhesiveness often become detached due to continuous cardiac contraction/relaxation in long term. To overcome such issues, facile and instantaneous and even robust adhesion to cardiac tissues is essential. Furthermore, when attached to the heart for an extended period, the materials used in epicardial devices should be exceptionally soft to avoid causing any tissue compression.

Researchers set out to develop a new adhesive epicardial patch that effectively overcomes the limitations of previously proposed designs. The patch they created now can be instantly attached to tissue on the heart's surface and could easily be fabricated on a large-scale.

Notably, their patch does not exert any unnecessary pressure on the heart's tissue for extended periods of time, which could improve both its safety and efficacy. It is comprised of three different but co-existing materials, namely a liquid-phase conducting composite, a network-shaped substrate, and an ionic adhesive.

The combination of these materials eliminates the need to suture the patch to the heart, making it easy to implement for medical professionals with varying degrees of experience, while also reducing the risk of complications associated with the suturing procedure.

 Heewon Choi et al, Adhesive bioelectronics for sutureless epicardial interfacing, Nature Electronics (2023). DOI: 10.1038/s41928-023-01023-w

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