Comment

Comment by Dr. Krishna Kumari Challa on March 31, 2023 at 10:21am

Severe hepatitis outbreak linked to common childhood viruses

A new  study brings scientists closer to understanding the causes of a mysterious rash of cases of acute severe hepatitis that began appearing in otherwise healthy children after COVID-19 lockdowns eased in several countries in the spring of 2022.

Pediatric hepatitis  is rare, and doctors were alarmed when they started seeing outbreaks of severe unexplained hepatitis. There have been about 1,000 cases to date; 50 of these children needed liver transplants and at least 22 have died.

In the study, published on March 30 in Nature, researchers linked the disease to co-infections from multiple common viruses, in particular a strain of adeno-associated virus type2 (AAV2). AAVs are not known to cause hepatitis on their own. They need "helper" viruses, such as adenoviruses that cause colds and flus, to replicate in the liver.

Once they returned to school, children were more susceptible to infections with these common pathogens. The study suggests that for a small subset of these children, getting more than one infection at the same time may have made them more vulnerable to severe hepatitis.

 The infections researchers detected in these children were caused not by an unusual, emerging virus, but by common childhood viral pathogens. 

Charles Chiu, Adeno-associated virus type 2 in US children with acute severe hepatitis, Nature (2023). DOI: 10.1038/s41586-023-05949-1. www.nature.com/articles/s41586-023-05949-1

Emma Thomson, Adeno-associated virus 2 infection in children with non-A-E hepatitis, Nature (2023). DOI: 10.1038/s41586-023-05948-2. www.nature.com/articles/s41586-023-05948-2

Comment by Dr. Krishna Kumari Challa on March 30, 2023 at 9:49am

Light-bending gravity reveals one of the biggest black holes ever found

A video showing how Astronomers used gravitational lensing to discover a black hole 30 billion times the mass of the sun in a galaxy 2 billion light years away. 

Comment by Dr. Krishna Kumari Challa on March 29, 2023 at 12:20pm

Using bacteria to convert CO2 in the air into a polyester

A team of chemical and biomolecular engineers at Korea Advanced Institute of Science and Technology has developed a scalable way to use bacteria to convert CO2 in the air into a polyester. In their paper, published in Proceedings of the National Academy of Sciences, the group describes their technique and outline its performance when tested over a several-hour period.

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How scientists cut their carbon footprints

As the effects of climate change grow, scientists from fields spanning astronomy to biology are trying to decarbonize their research. They say that the time for carbon-footprint assessments is over — we must take action, and that needs institutional support. “The situation is not that different from the one you can experience as a citizen,” says Pierrick Martin, an astrophysicist at an institute that is trying to reduce the heavy toll of its observatory. “There are things you can do yourself, at your level, in your local environment, that are worth something. But this has limits, and you can’t escape from political decisions at some point.”

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'Too comfortable in our own comfort': Expert on why we shouldn't wa... It's common knowledge that reducing our carbon footprint is important, but what about our

Comment by Dr. Krishna Kumari Challa on March 29, 2023 at 12:17pm

Researchers identify specific regions of the brain damaged by high blood pressure, involved in mental decline, dementia

For the first time, researchers have identified specific regions of the brain that are damaged by high blood pressure and may contribute to a decline in mental processes and the development of dementia.

High blood pressure is known to be involved in causing dementia and damage to brain function. The study, which is published in the European Heart Journal recently, shows how this happens. It gathered information from a combination of magnetic resonance imaging (MRI) of brains, genetic analyses and observational data from thousands of patients to look at the effect of high blood pressure on cognitive function.

The researchers then checked their findings in a separate, large group of patients in Italy who had high blood pressure, and found that the parts of the brain the researchers had identified were indeed affected. Further research also found that genes that cause high BP and other factors are not involved in these changes.

The researchers found changes to nine parts of the brain were related to higher blood pressure and worse cognitive function. These included the putamen, which is a round structure in the base of the front of the brain, responsible for regulating movement and influencing various types of learning. Other areas affected were the anterior thalamic radiation, anterior corona radiata and anterior limb of the internal capsule, which are regions of white matter that connect and enable signaling between different parts of the brain. The anterior thalamic radiation is involved in executive functions, such as the planning of simple and complex daily tasks, while the other two regions are involved in decision-making and the management of emotions.

The changes to these areas included decreases in brain volume and the amount of surface area on the brain cortex, changes to connections between different parts of the brain, and changes in measures of brain activity.

Tomasz J Guzik et al, Genetic analyses identify brain structures related to cognitive impairment associated with elevated blood pressure, European Heart Journal (2023). DOI: 10.1093/eurheartj/ehad101

Ernesto L. Schiffrin et al, Hypertension, brain imaging phenotypes and cognitive impairment: lessons from Mendelian randomisation, European Heart Journal (2023). DOI: 10.1093/eurheartj/ehad187

Comment by Dr. Krishna Kumari Challa on March 29, 2023 at 8:14am

Are Air Fryers Healthy For Us?

Comment by Dr. Krishna Kumari Challa on March 28, 2023 at 12:28pm

Methane changes this equation. By holding on to energy from the sun, methane is introducing heat the atmosphere no longer needs to get from precipitation.

Additionally, methane shortwave absorption decreases the amount of solar radiation reaching Earth's surface. This in turn reduces the amount of water that evaporates. Generally, precipitation and evaporation are equal, so a decrease in evaporation leads to a decrease in precipitation.

This has implications for understanding in more detail how methane and perhaps other greenhouses gases can impact the climate system. Shortwave absorption softens the overall warming and rain-increasing effects but does not eradicate them at all.

Robert J. Allen et al, Surface warming and wetting due to methane's long-wave radiative effects muted by short-wave absorption, Nature Geoscience (2023). DOI: 10.1038/s41561-023-01144-z

Part 2

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Comment by Dr. Krishna Kumari Challa on March 28, 2023 at 12:26pm

Methane cools even as it heats

Most climate models do not yet account for a new  discovery: methane traps a great deal of heat in Earth's atmosphere, but also creates cooling clouds that offset 30% of the heat!

Greenhouse gases like methane create a kind of blanket in the atmosphere, trapping heat from Earth's surface, called longwave energy, and preventing it from radiating out into space. This makes the planet hotter.

A blanket doesn't create heat, unless it's electric. You feel warm because the blanket inhibits your body's ability to send its heat into the air. This is the same concept.

In addition to absorbing longwave energy, it turns out methane also absorbs incoming energy from the sun, known as shortwave energy. This should warm the planet. But counterintuitively, the shortwave absorption encourages changes in clouds that have a slight cooling effect.

This effect is detailed in the journal Nature Geoscience, alongside a second finding that the researchers did not fully expect. Though methane generally increases the amount of precipitation, accounting for the absorption of shortwave energy suppresses that increase by 60%.

Both types of energy—longwave (from Earth) and shortwave (from sun)—escape from the atmosphere more than they are absorbed into it. The atmosphere needs compensation for the escaped energy, which it gets from heat created as water vapour condenses into rain, snow, sleet, or hail.

Essentially, precipitation acts as a heat source, making sure the atmosphere maintains a balance of energy.

Part 1

Comment by Dr. Krishna Kumari Challa on March 28, 2023 at 11:56am

The researchers found that in countries where antibiotics are taken more regularly, their populations also have higher numbers of resistance genes in their gut microbiome.

The reason this collateral damage is such a major problem is that microbes are constantly sharing genes with each other. Known as horizontal gene transfer, this process helps AMR genes to spread back and forth between species. Our bodies are continually importing and exporting microbes and pathogen strains. These strains are themselves passing genes back and forth, which means the challenge of AMR has to be tackled at both the micro and macro level. Given our complex relationship with microbes, we need to do more research to understand how we maximize the benefits and minimize the risks when it comes to guiding treatment decisions and developing new medicines.

We've known for some years that antimicrobial resistance genes can spread incredibly fast between gut bacteria. This study is so important because it can, for the first time, quantify the impact national antibiotic usage has on our commensal bacteria, as well as giving us insights into the common types of resistance we can expect to evolve.

Kihyun Lee et al, Population-level impacts of antibiotic usage on the human gut microbiome, Nature Communications (2023). DOI: 10.1038/s41467-023-36633-7

Part 2

Comment by Dr. Krishna Kumari Challa on March 28, 2023 at 11:53am

Human body is a breeding ground for antimicrobial resistance genes, shows new study

The community of microbes living in and on our bodies may be acting as a reservoir for antibiotic resistance, according to new research.

The use of antibiotics leads to "collateral damage" to the microbiome, ramping up the number of resistance genes being passed back and forth between strains in the microbiome. The findings also suggest these genes spread so easily through a population, that regardless of your own health and habits, the number of resistance genes in your gut is heavily influenced by national trends in antibiotic consumption.

The rise of antimicrobial resistance (AMR) among human pathogens is widely seen as one of the most serious threats to global health in the coming decades. AMR is already believed to be contributing to tens of thousands of deaths in the world each year.

Tracking the emergence and spread of genes that help these pathogens to shrug off antibiotics has generally been limited to samples taken from infected individuals. The majority of microbes living in the human body, however, are not pathogenic.

The human microbiome is a complex and dynamic community of millions of species of microbes, primarily living in the gut and coexisting with us. Microbiomes play an important role in health and disease, with the gut microbiome known to help with the digestion of food and the development of our immune system.

Even a healthy individual who hasn't taken antibiotics recently is constantly bombarded by microbes from people or even pets they interact with, which leads to resistance genes becoming embedded in their own microbiota. If they exist in a population with a heavy burden of antibiotic consumption, it leads to more resistance genes in their microbiome.

To better understand the impact of antimicrobials on the gut microbiome, researchers analyzed over 3,000 gut microbiome samples, collected from healthy individuals across 14 countries. They then compared the resistance genes identified in samples to those found in large genome collections in order to understand the movement of AMR genes between microbe and pathogen species.

They carefully catalogued and recorded the number of antimicrobial resistance genes found in the samples by comparing data to the Comprehensive Antibiotic Resistance Database, a public health resource where resistance genes are documented.

The team identified a median of 16 AMR genes per stool sample analyzed. They also found that the median number of genes varied across the 14 countries for which they had data. For example, they saw a five-fold variation in median resistance levels between the lowest in the Netherlands and the highest in Spain.

Using World Health Organization and ResistanceMap data, the team were able to show a strong correlation between the frequency of resistance genes present in a country and national antibiotic consumption levels.

Part 1

Comment by Dr. Krishna Kumari Challa on March 28, 2023 at 11:42am

The reaction produces different isomers—molecules that all have the same mass, but slightly different structures. With standard mass spectrometry, all these variants produce the same signal. But the outcome is different when using photoelectron photoion coincidence spectroscopy, the method adopted by the team. With this technique, the structure of the measurement curve allows conclusions to be drawn about each individual isomer.

The universe contains a wild jungle of molecules and chemical reactions—not all of them can be distinctly classified in the signals from telescopes.

Scientists already know from models that both corannulene and vinylacetylene exist in the universe. Now it has been possible to confirm that these molecules actually form the building blocks to fullerene.

 The researchers want to conduct more experiments in order to understand how the classic buckyballs form in the universe, along with the football-shaped fullerene molecules with 60 carbon atoms and the minute nanotubes with even more atoms.

Lotefa B. Tuli et al, Gas phase synthesis of the C₄₀ nano bowl C₄₀H₁₀, Nature Communications (2023). DOI: 10.1038/s41467-023-37058-y

Part 2

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