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Comment by Dr. Krishna Kumari Challa on July 7, 2022 at 9:59am

Physicists see electron whirlpools for the first time

Though they are discrete particles, water molecules flow collectively as liquids, producing streams, waves, whirlpools, and other classic fluid phenomena.

Not so with electricity. While an electric current is also a construct of distinct particles—in this case, electrons—the particles are so small that any collective behavior among them is drowned out by larger influences as electrons pass through ordinary metals. But, in certain materials and under specific conditions, such effects fade away, and electrons can directly influence each other. In these instances, electrons can flow collectively like a fluid.

Now, physicists  have observed electrons flowing in vortices, or whirlpools—a hallmark of fluid flow that theorists predicted electrons should exhibit, but that has never been seen until now.

It's a clear signature  where electrons behave as a fluid, not as individual particles.

The observations, reported in the journal Nature, could inform the design of more efficient electronics.

When electrons go in a fluid state, [energy] dissipation drops, and that's of interest in trying to design low-power electronics. This new observation is another step in that direction.

Eli Zeldov, Direct observation of vortices in an electron fluid, Nature (2022). DOI: 10.1038/s41586-022-04794-y. www.nature.com/articles/s41586-022-04794-y

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 9:16am

Scientists unravel the key to colon cancer relapse after chemotherapy

Approximately 1 in 25 people will develop colon cancer during their lifetime and nearly 2 million cases new cases are diagnosed worldwide each year. Chemotherapy is commonly used to treat colon cancer. While this treatment is initially effective in most cases, many patients relapse after treatment.

This study reveals that some tumor cells remain in a latent state and, after chemotherapy, they are reactivated, thus causing relapse. Their study is published in Nature Cancer.

In short, scientists have discovered that tumor stem cells with Mex3a protein activity remain in a state of latency that confers resistance to chemotherapy. Due to the action of the drugs used in this treatment, these cells adopt a state similar to the embryonic one, and sometime after chemotherapy, when the environment is more favorable, they are reactivated to regenerate the tumor in all its complexity. These persistent cells are responsible for cancer relapse after treatment.

https://www.nature.com/articles/s43018-022-00402-0

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 9:05am

Defining the Anthropocene: Radioactive traces in ocean materials mark the start of the modern age

For the first time, researchers can offer a strong quantitative definition for the start of what is known as the Anthropocene, thanks to traces of radioactive material in marine sediments and corals. The Anthropocene period is considered important by researchers in many fields as it effectively marks a milestone for humanity's impact on Earth's environment and ecosystem.

Researchers combined records of nuclear fallout from atomic tests present in ocean sediments and coral skeletons. These records show a clear change in the ocean environment before, during and after a period of worldwide atomic testing, which the researchers have defined as marking the beginning of the Anthropocene.

 Yusuke Yokoyama et al, Plutonium isotopes in the North Western Pacific sediments coupled with radiocarbon in corals recording precise timing of the Anthropocene, Scientific Reports (2022). DOI: 10.1038/s41598-022-14179-w

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 8:44am

LHCb discovers three new exotic particles: the pentaquark and the first-ever pair of tetraquarks

The international LHCb collaboration at the Large Hadron Collider (LHC) has observed three never-before-seen particles: a new kind of pentaquark and the first-ever pair of tetraquarks, which includes a new type of tetraquark. The findings, presented recently at a CERN seminar, add three new exotic members to the growing list of new hadrons found at the LHC. They will help physicists better understand how quarks bind together into these composite particles.

Quarks are elementary particles and come in six flavors: up, down, charm, strange, top and bottom. They usually combine together in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei. More rarely, however, they can also combine into four-quark and five-quark particles, or "tetraquarks" and "pentaquarks." These exotic hadrons were predicted by theorists at the same time as conventional hadrons, about six decades ago, but only relatively recently, in the past 20 years, have they been observed by LHCb and other experiments.

Most of the exotic hadrons discovered in the past two decades are tetraquarks or pentaquarks containing a charm quark and a charm antiquark, with the remaining two or three quarks being an up, down or strange quark or their antiquarks. But in the past two years, LHCb has discovered different kinds of exotic hadrons. Two years ago, the collaboration discovered a tetraquark made up of two charm quarks and two charm antiquarks, and two "open-charm" tetraquarks consisting of a charm antiquark, an up quark, a down quark and a strange antiquark. And last year it found the first-ever instance of a "double open-charm" tetraquark with two charm quarks and an up and a down antiquark. Open charm means that the particle contains a charm quark without an equivalent antiquark.

The discoveries announced now by the LHCb collaboration include new kinds of exotic hadrons. The first kind, observed in an analysis of "decays" of negatively charged B mesons, is a pentaquark made up of a charm quark and a charm antiquark and an up, a down and a strange quark. It is the first pentaquark found to contain a strange quark. The finding has a whopping statistical significance of 15 standard deviations, far beyond the 5 standard deviations that are required to claim the observation of a particle in particle physics.

The second kind is a doubly electrically charged tetraquark. It is an open-charm tetraquark composed of a charm quark, a strange antiquark, and an up quark and a down  antiquark, and it was spotted together with its neutral counterpart in a joint analysis of decays of positively charged and neutral B mesons. The new tetraquarks, observed with a statistical significance of 6.5 (doubly charged particle) and 8 (neutral particle) standard deviations, represent the first time a pair of tetraquarks has been observed.

https://lhcb-outreach.web.cern.ch/2022/07/05/observation-of-a-stran...

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 7:58am

8,000 kilometers per second: Star with the shortest orbital period around black hole discovered

Researchers have discovered the fastest known star, which travels around a black hole in record time. The star, S4716, orbits Sagittarius A*, the black hole in the center of our Milky Way, in four years and reaches a speed of around 8,000 kilometers per second. S4716 comes as close as 100 AU (astronomical unit) to the black hole—a small distance by astronomical standards. One AU corresponds to 149,597,870 kilometers. The study has been published in The Astrophysical Journal.

Florian Peißker et al, Observation of S4716—a Star with a 4 yr Orbit around Sgr A*, The Astrophysical Journal (2022). DOI: 10.3847/1538-4357/ac752f

Comment by Dr. Krishna Kumari Challa on July 5, 2022 at 12:37pm

Study explores coevolution of mammals and their lice

According to a new study, the first louse to take up residence on a mammalian host likely started out as a parasite of birds. That host-jumping event tens of millions of years ago began the long association between mammals and lice, setting the stage for their coevolution and offering more opportunities for the lice to spread to other mammals.

Reported in the journal Nature Ecology and Evolution, the study compared the genomes and family trees of lice and their mammalian hosts. The effort revealed that the two trees share a lot of parallel branches and twigs. Those branching points—where one group of mammals began diverging into new forms—often were echoed in the genomes of the lice that parasitized those mammals, the researchers reported.

In this paper, researchers used data from genome sequencing to show that a major newly recognized group of mammalian lice, including lice of humans, originated on the common ancestor of Afrotheria, a group of mammals primarily of African distribution that includes elephants, hyraxes and elephant shrews, among others. These lice then went on to colonize other major groups of mammals through the process of host switching.

Lice fall into two groups based on their eating habits. Chewing lice munch on skin or secretions, while sucking lice pierce the skin to consume the blood of their hosts. Both types feed on mammals, but sucking lice are exclusive to mammals.

Recent genomic studies revealed that sucking lice are closely related to two groups of chewing lice that also feed on mammals, and "each of the major groups within this newly identified lineage occurs on at least one member of Afrotheria.

Kevin Johnson, Phylogenomics reveals the origin of mammal lice out of Afrotheria, Nature Ecology & Evolution (2022). DOI: 10.1038/s41559-022-01803-1. www.nature.com/articles/s41559-022-01803-1

Comment by Dr. Krishna Kumari Challa on July 2, 2022 at 12:24pm

100 Fun Facts collected from Google's "i'm feeling curious" feature

Comment by Dr. Krishna Kumari Challa on July 2, 2022 at 12:18pm

Blood pressure e-tattoo promises continuous monitoring

Comment by Dr. Krishna Kumari Challa on July 2, 2022 at 12:11pm

Culinary foams are usually created by adding a thickening or gelling agent to a liquid or a solid that has been pureed, and then either whipping it to incorporate air or using a specialized siphon that injects gases such as carbon dioxide or compressed air.

The team created a modified siphon that could be attached to any kind of gas cannister, allowing them to incorporate carbon monoxide into their foam. To create the foams, they used food additives such as alginate, methyl cellulose, and maltodextrin. Xantham gum was also added to stabilize the foams. By varying the amount of xantham gum, the researchers could control how long it would take for the gas to be released once the foams were administered.

After showing that they could control the timing of the gas release in the body, the researchers decided to test the foams for a few different applications. First, they studied two types of topical applications, analogous to applying a cream to soothe itchy or inflamed areas. In a study of mice, they found that delivering the foam rectally reduced inflammation caused by colitis or radiation-induced proctitis (inflammation of the rectum that can be caused by radiation treatment for cervical or prostate cancer).

Current treatments for colitis and other inflammatory conditions such as Crohn’s disease usually involve drugs that suppress the immune system, which can make patients more susceptible to infections. Treating those conditions with a foam that can be applied directly to inflamed tissue offers a potential alternative, or complementary approach, to those immunosuppressive treatments, the researchers say. While the foams were given rectally in this study, it could also be possible to deliver them orally, the researchers say.

https://news.mit.edu/2022/carbon-monoxide-foam-inflammation-0629

Part2

Comment by Dr. Krishna Kumari Challa on July 2, 2022 at 12:10pm

Could carbon monoxide foam help fight inflammation?

Carbon monoxide is best known as a potentially deadly gas. However, in small doses it also has beneficial qualities: It has been shown to reduce inflammation and can help stimulate tissue regeneration.

We’ve known for years that carbon monoxide can impart beneficial effects in all sorts of disease pathologies, when given as an inhaled gas. However, it’s been a challenge to use it in the clinic, for a number of reasons related to safe and reproducible administration, and health care workers’ concerns, which has led to people wanting to find other ways to administer it.

A team of researchers  has now devised a novel way to deliver carbon monoxide to the body while bypassing its potentially hazardous effects. Inspired by techniques used in molecular gastronomy, they were able to incorporate carbon monoxide into stable foams that can be delivered to the digestive tract.

In a study of mice, the researchers showed that these foams reduced inflammation of the colon and helped to reverse acute liver failure caused by acetaminophen overdose. The new technique, described earlier this week in a Science Translational Medicine paper, could also be used to deliver other therapeutic gases, the researchers say.

The ability to deliver a gas opens up whole new opportunities of how we think of therapeutics. We generally don’t think of a gas as a therapeutic that you would take orally (or that could be administered rectally), so this offers an exciting new way to think about how we can help patients.

Since the late 1990s, researchers have been studying the therapeutic effects of low doses of carbon monoxide. The gas has been shown to impart beneficial effects in preventing rejection of transplanted organs, reducing tumor growth, and modulating inflammation and acute tissue injury.

When inhaled at high concentrations, carbon monoxide binds to hemoglobin in the blood and prevents the body from obtaining enough oxygen, which can lead to serious health effects and even death. However, at lower doses, it has beneficial effects such as reducing inflammation and promoting tissue regeneration.

To tackle the challenge of delivering a gas, researchers  came up with the idea of incorporating the gas into a foam, much the way that chefs use carbon dioxide to create foams infused with fruits, vegetables, or other flavours.

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