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Comment by Dr. Krishna Kumari Challa on June 26, 2021 at 8:37am

A sweet solution to plastic pollution

Comment by Dr. Krishna Kumari Challa on June 26, 2021 at 8:32am

SARS-CoV-2 virus can find alternate route to infect cells

Early in the COVID-19 pandemic, scientists identified how SARS-CoV-2, the virus that causes COVID-19, gets inside cells to cause infection. All current COVID-19 vaccines and antibody-based therapeutics were designed to disrupt this route into cells, which requires a receptor called ACE2.

Now researchers have found that a single mutation gives SARS-CoV-2 the ability to enter cells through another route—one that does not require ACE2. The ability to use an alternative entry pathway opens up the possibility of evading COVID-19 antibodies or vaccines, but the researchers did not find evidence of such evasion. However, the discovery does show that the virus can change in unexpected ways and find new ways to cause infection. The study is published June 23 in Cell Reports.

This mutation occurred at one of the spots that changes a lot as the virus circulates in the human population. Most of the time, alternative receptors and attachment factors simply enhance ACE2-dependent entry. But in this case, it was discovered an alternative way to infect a key cell type—a human lung cell—and that the virus acquired this ability via a mutation that  arises in the population. 

Maritza Puray-Chavez et al, Systematic analysis of SARS-CoV-2 infection of an ACE2-negative human airway cell, Cell Reports (2021). DOI: 10.1016/j.celrep.2021.109364

https://phys.org/news/2021-06-sars-cov-virus-alternate-route-infect...

Comment by Dr. Krishna Kumari Challa on June 26, 2021 at 8:10am

Study shows potential dangers of sweeteners

New research has discovered that common artificial sweeteners can cause previously healthy gut bacteria to become diseased and invade the gut wall, potentially leading to serious health issues.

The study, published in the International Journal of Molecular Sciences, is the first to show the pathogenic effects of some of the most widely used artificial sweeteners—saccharin, sucralose, and aspartame—on two types of gut bacteria, E. coli (Escherichia coli) and E. faecalis (Enterococcus faecalis).

Previous studies have shown that artificial sweeteners can change the number and type of bacteria in the gut, but this new molecular research, led by academics from Anglia Ruskin University (ARU), has demonstrated that sweeteners can also make the bacteria pathogenic. It found that these pathogenic bacteria can attach themselves to, invade, and kill Caco-2 cells, which are epithelial cells that line the wall of the intestine.

It is known that bacteria such as E. faecalis which cross the intestinal wall can enter the blood stream and congregate in the lymph nodes, liver, and spleen, causing a number of infections including septicaemia.

This new study discovered that at a concentration equivalent to two cans of diet soft drink, all three artificial sweeteners significantly increased the adhesion of both E. coli and E. faecalis to intestinal Caco-2 cells, and differentially increased the formation of biofilms.

Bacteria growing in biofilms are less sensitive to antimicrobial resistance treatment and are more likely to secrete toxins and express virulence factors, which are molecules that can cause disease.

Additionally, all three sweeteners caused the pathogenic gut bacteria to invade Caco-2 cells found in the wall of the intestine, with the exception of saccharin which had no significant effect on E. coli invasion.

Aparna Shil et al, Artificial Sweeteners Negatively Regulate Pathogenic Characteristics of Two Model Gut Bacteria, E. coli and E. faecalis, International Journal of Molecular Sciences (2021). DOI: 10.3390/ijms22105228

https://medicalxpress.com/news/2021-06-potential-dangers-sweeteners...

Comment by Dr. Krishna Kumari Challa on June 26, 2021 at 8:01am

'Dragon man' fossil may replace Neanderthals as our closest relative

A near-perfectly preserved ancient human fossil known as the Harbin cranium sits in the Geoscience Museum in Hebei GEO University. The largest of known Homo skulls, scientists now say this skull represents a newly discovered human species named Homo longi or "Dragon Man." Their findings, appearing in three papers publishing June 25 in the journal The Innovation, suggest that the Homo longi lineage may be our closest relatives—and has the potential to reshape our understanding of human evolution.

The Harbin fossil is one of the most complete human cranial fossils in the world. This fossil preserved many morphological details that are critical for understanding the evolution of the Homo genus and the origin of Homo sapiens.

The cranium was reportedly discovered in the 1930s in Harbin City of the Heilongjiang province of China. The massive skull could hold a brain comparable in size to modern humans' but had larger, almost square eye sockets, thick brow ridges, a wide mouth, and oversized teeth. "While it shows typical archaic human features, the Harbin cranium presents a mosaic combination of primitive and derived characters setting itself apart from all the other previously-named Homo species leading to its new species designation of Homo longi. 

This reconstruction of the human tree of life also suggests that the common ancestor we share with Neanderthals existed even further back in time. "The divergence time between H. sapiens and the Neanderthals may be even deeper in evolutionary history than generally believed, over one million years. findings gathered from the Harbin cranium have the potential to rewrite major elements of human evolution. Their analysis into the life history of Homo longi suggest they were strong, robust humans whose potential interactions with Homo sapiens may have shaped our history in turn. 

The Innovation, Shao et al.: "Geochemical provenancing and direct dating of the Harbin archaic human cranium" www.cell.com/the-innovation/fu … 2666-6758(21)00056-4 DOI: 10.1016/j.xinn.2021.100131

The Innovation, Ji et al.: "Late Middle Pleistocene Harbin cranium represents a new Homo species" www.cell.com/the-innovation/fu … 2666-6758(21)00057-6 DOI: 10.1016/j.xinn.2021.100132

The Innovation, Ni et al.: "Massive cranium from Harbin in northeastern China establishes a new Middle Pleistocene human lineage" www.cell.com/the-innovation/fu … 2666-6758(21)00055-2 DOI: 10.1016/j.xinn.2021.100130

https://phys.org/news/2021-06-dragon-fossil-neanderthals-closest-re...

Comment by Dr. Krishna Kumari Challa on June 25, 2021 at 11:15am

The gift of the short-sleep gene

For the last 16 years, the Johnson family has been studied for their tendency to get by happily on very little sleep. “If you paid me a million dollars to sleep eight hours tonight, I couldn’t,” says Brad Johnson. “I'd get five hours and be done… just ready to roll.” Research revealed that many members of the family have a mutation in the gene DEC2, which seems to regulate sleep length in mammals. Short sleepers tend to also be particularly lively when they’re awake, with marathons being a popular hobby among them. “I've run a lot of marathons,” says Brad Johnson. “Reading, studying, correspondence, writing — all those things are great to do early in the morning or late at night.” It’s been “a true gift”.

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Continuous activity of small earthquakes makes mountains grow

From a human perspective, earthquakes are natural disasters—in the past hundred years, they have caused more than 200,000 deaths and enormous economic damage. Mega-earthquakes with a magnitude of nine or higher on the Richter scale are considered a particular threat. Yet the inconceivable energy released in these events doesn't seem to affect the uplift of mountains, according to a new study by geoscientists at the University of Tübingen. The energy of small earthquakes that work steadily in the background appears to play a far greater role in shaping the landscape. In Chile and Japan, Professor Todd Ehlers and Dr. Andrea Madella found parallels between seismic activity and the pattern and rate of mountain uplift. The results have been published in the journal Nature Geoscience.

Comment by Dr. Krishna Kumari Challa on June 25, 2021 at 11:04am

Cosmic Hand Hitting a Wall

Comment by Dr. Krishna Kumari Challa on June 25, 2021 at 10:40am

Scientists can predict and design single atom catalysts for important chemical reactions

Researchers have demonstrated that a catalyst can indeed be an agent of change. In a study published today in Science, they used quantum chemical simulations run on supercomputers to predict a new catalyst architecture as well as its interactions with certain chemicals, and demonstrated in practice its ability to produce propylene—currently in short supply—which is critically needed in the manufacture of plastics, fabrics and other chemicals. The improvements have potential for highly efficient, "greener" chemistry with a lower carbon footprint.

 "First-principles design of a single-atom–alloy propane dehydrogenation catalyst" Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abg8389

https://phys.org/news/2021-06-scientists-atom-catalysts-important-c...

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Comment by Dr. Krishna Kumari Challa on June 25, 2021 at 10:37am

No lab required: New technology can diagnose infections in minutes

Engineering, biochemistry and medical researchers have combined their skills to create a hand-held rapid test for bacterial infections that can produce accurate, reliable results in less than an hour, eliminating the need to send samples to a lab.

Their proof-of-concept research, published today in the journal Nature Chemistry, specifically describes the test's effectiveness in diagnosing urinary tract infections from real clinical samples. The researchers are adapting the test to detect other forms of bacteria and for the rapid diagnosis of viruses, including COVID-19. They also plan to test its viability for detecting markers of cancer.

The new DNA-based technology uses a handheld device similar to a blood-glucose monitor. A microchip analyzes a droplet of bodily fluid such as blood, urine or saliva, using molecules that can detect the specific protein signature of an infection. The device, about the size of a USB stick, plugs into a smartphone, which displays the result.

Integrating programmable DNAzymes with electrical readout for rapid and culture-free bacterial detection using a handheld platform, Nature Chemistry (2021). DOI: 10.1038/s41557-021-00718-x , www.nature.com/articles/s41557-021-00718-x

https://phys.org/news/2021-06-lab-required-technology-infections-mi...

Comment by Dr. Krishna Kumari Challa on June 25, 2021 at 10:11am

Genome study reveals East Asian coronavirus epidemic 20,000 years ago

An international study has discovered a coronavirus epidemic broke out in the East Asia region more than 20,000 years ago, with traces of the outbreak evident in the genetic makeup of people from that area.

In the past 20 years, there have been three outbreaks of epidemic severe coronaviruses: SARS-CoV leading to Severe Acute Respiratory Syndrome, which originated in China in 2002 and killed more than 800 people; MERS-CoV leading to Middle East Respiratory Syndrome, which killed more than 850 people, and SARS-CoV-2 leading to COVID-19, which has killed 3.8 million people.

But this study of the evolution of the human genome has revealed another large coronavirus epidemic broke out thousands of years earlier.

The modern human genome contains evolutionary information tracing back tens of thousands of years, like studying the rings of a tree gives us insight into the conditions it experienced as it grew.

In the study, the researchers used data from the 1000 Genomes Project, which is the largest public catalog of common human genetic variation, and looked at the changes in the human genes coding for SARS-CoV-2 interacting proteins.

COVID epidemic 20000 years ago

https://www.youtube.com/watch?v=8_I9oVhlrjE

An international study has discovered a coronavirus epidemic broke out in the East Asia region more than 20,000 years ago, with traces of the outbreak evident in the genetic makeup of people from that area.

Dr. KKC

East Asian people come from the area that is now China, Japan, Mongolia, North Korea, South Korea, and Taiwan.

In the course of the epidemic, selection favored variants of pathogenesis-related human genes with adaptive changes presumably leading to a less severe disease

 Current Biology (2021). DOI: 10.1016/j.cub.2021.05.067

Comment by Dr. Krishna Kumari Challa on June 25, 2021 at 8:54am

Stress really does turn hair grey – but it can be reversed

Stress can turn your hair prematurely grey. A study by researchers  has provided the first quantitative evidence that this is in fact the case – and not only that, but hair can go back to its original colour if the stress is removed.

The new data add to a growing body of evidence demonstrating that human ageing is not a linear, fixed biological process but may, at least in part, be halted or even temporarily reversed.

It was found that  some hairs had regained their pigmentation when the stress was lifted. 

Unfortunately, this doesn’t mean that all greying is reversible. Scientists don’t think that reducing stress in a 70-year-old who’s been grey for years will darken their hair or increasing stress in a 10-year-old will be enough to tip their hair over the grey threshold.

https://elifesciences.org/articles/67437

https://www.sciencefocus.com/news/stress-really-does-turn-hair-grey...

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