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Comment by Dr. Krishna Kumari Challa on November 9, 2023 at 8:53am

This is how the scientists described their work:

After we prepared the hydrogel, we embedded photosynthetic—or sunlight-capturing—bacteria called cyanobacteria into the gel.

The cyanobacteria embedded in the material still needed to take in light and carbon dioxide to perform photosynthesis, which keeps them alive. The hydrogel was porous enough to allow that, but to make the configuration as efficient as possible, we 3D-printed the gel into custom shapes—grids and honeycombs. These structures have a higher surface-to-volume ratio that allow more light, CO₂ and nutrients to come into the material.
Like all other bacteria, cyanobacteria has different genetic circuits, which tell the cells what outputs to produce. Our team genetically engineered the bacterial DNA so that the cells created a specific enzyme called laccase.

The laccase enzyme produced by the cyanobacteria works by performing a chemical reaction with a pollutant that transforms it into a form that's no longer functional. By breaking the chemical bonds, it can make a toxic pollutant nontoxic. The enzyme is regenerated at the end of the reaction, and it goes off to complete more reactions.

 Debika Datta et al, Phenotypically complex living materials containing engineered cyanobacteria, Nature Communications (2023). DOI: 10.1038/s41467-023-40265-2

Comment by Dr. Krishna Kumari Challa on November 9, 2023 at 8:51am

Engineered 'living materials' could help clean up water pollution one day

Water pollution is a growing concern globally, with research estimating that chemical industries discharge 300–400 megatonnes (600–800 billion pounds) of industrial waste into bodies of water each year. As a team of materials scientists, we're working on an engineered "living material" that may be able to transform chemical dye pollutants from the textile industry into harmless substances.

Water pollution is both an environmental and humanitarian issue that can affect ecosystems and human health alike. We're hopeful that the materials we're developing could be one tool available to help combat this problem.
The "engineered living material" scientists have been working on contains programmed bacteria embedded in a soft hydrogel material.
The hydrogel that forms the base of the material has similar properties to Jell-O—it's soft and made mostly of water. Our particular hydrogel is made from a natural and biodegradable seaweed-based polymer called alginate, an ingredient common in some foods.

The alginate hydrogel provides a solid physical support for bacterial cells, similar to how tissues support cells in the human body. We intentionally chose this material so that the bacteria we embedded could grow and flourish.
Part 1

Comment by Dr. Krishna Kumari Challa on November 9, 2023 at 8:26am

Cheetahs become more nocturnal on hot days. Climate change may trigger fights among predators

Changing temperatures can impact the behavior patterns of large carnivore species and also the dynamics among species.

Cheetahs are usually daytime hunters, but the speedy big cats will shift their activity toward dawn and dusk hours during warmer weather, a new study finds.

Unfortunately for endangered cheetahs, that sets them up for more potential conflicts with mostly nocturnal competing predators such as lions and leopards, say the authors of research published recently in the journal Proceedings of the Royal Society B.

While cheetahs only eat fresh meat, lions and leopards will sometimes opportunistically scavenge from smaller predators.

Lions and leopards normally kill prey themselves, but if they come across a cheetah's kill, they will try to take it. The cheetahs will not fight the larger cats, they will just leave.

Hunting at different times of the day is one long-evolved strategy to reduce encounters between the multiple predator species. But the new study found that on the hottest days, when maximum daily temperatures soared to nearly 45 degrees Celsius (113 degrees Fahrenheit), cheetahs became more nocturnal—increasing their overlapping hunting hours with rival big cats by 16%.

There's a greater chance for more unfriendly encounters and less food for the cheetahs because of global warming. 

Kasim Rafiq et al, Increasing ambient temperatures trigger shifts in activity patterns and temporal partitioning in a large carnivore guild, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2023.1938

Comment by Dr. Krishna Kumari Challa on November 9, 2023 at 8:20am

 Willow bark extract has broad-spectrum antiviral effect

We need safe, sustainable antiviral options to treat the outbreaks of the future. Scientists  have now shown that an extract of willow bark—a plant that has already provided several medicines, including the precursor to modern aspirin—has a broad-spectrum antiviral effect in cell sample experiments.

The extract worked both on enveloped coronaviruses, which cause colds as well as COVID-19, and non-enveloped enteroviruses, which cause infections such as flu and meningitis. There are no clinically approved drugs that work against enteroviruses directly, so this extract could be a future game-changer.

The scientists had previously tested willow bark extract on enteroviruses, and found it was highly successful. In this new study, they expanded the remit of their research to look at additional kinds of virus and to try to understand the mechanism of the extract's action.

Willow (Salix spp.) bark hot extracts inhibit both enveloped and nonenveloped viruses: study on its anti-coronavirus and anti-enterovirus activities, Frontiers in Microbiology (2023). DOI: 10.3389/fmicb.2023.1249794

Comment by Dr. Krishna Kumari Challa on November 9, 2023 at 8:14am

This study showed that when participants received methylphenidate orally, the rate of dopamine increases peaked more than an hour after administration. Comparatively, when participants received an intravenous injection of methylphenidate, the rate of dopamine increases peaked much faster—within 5 to 10 minutes of the administration.

Through the fMRI, researchers observed that one brain region, the  ventromedial prefrontal cortex,  was less active after both oral and intravenous administration of the study drug. However, two brain regions, the dorsal anterior cingulate cortex and the insula, which are part of the brain's salience network, were activated only after receiving the injection of methylphenidate, the more addictive route of drug administration. These same areas of the brain were not activated after taking methylphenidate orally, the route with lower addiction potential. This finding was consistent among all 20 research participants.

The salience network attributes value to things in our environment and is important for recognizing and translating internal sensations—including the subjective effects of drugs. This research adds to a growing body of evidence documenting the important role that the salience network appears to play in substance use and addiction. For instance, studies have shown that people who experience damage to the insula, part of the brain's salience network, can have a complete remission of their addiction.

 P Manza, et al. Neural circuit selective for fast but not slow dopamine increases in drug reward, Nature Communications (2023). DOI: 10.1038/s41467-023-41972-6. www.nature.com/articles/s41467-023-41972-6

Part 2

Comment by Dr. Krishna Kumari Challa on November 9, 2023 at 8:10am

Researchers identify brain network that is uniquely activated through injection vs. oral drug use

Understanding the brain mechanisms that underlie addiction is crucial for informing prevention interventions, developing new therapies for substance use disorders, and addressing the overdose crisis.

Results from a new clinical trial suggest that a group of brain regions known as the "salience network" is activated after a drug is taken intravenously, but not when that same drug is taken orally.

When drugs enter the brain quickly, such as through injection or smoking, they are more addictive than when they enter the brain more slowly, such as when they are taken orally. However, the brain circuits underlying these differences are not well understood. This study offers new information that helps explain what may be causing this difference.

People who smoke or inject drugs—two methods that deliver drugs to the brain quickly—often report doing so to get faster relief from withdrawal or to experience euphoria more quickly. However, drug smoking and injection are associated with developing a substance use disorder more quickly than taking drugs orally or by insufflation (e.g., snorting).

In addition, injecting drugs is also associated with higher rates of infectious diseases and overdose. To better understand how route of drug administration impacts the brain's response to the drug, researchers conducted a double-blind, randomized, counterbalanced clinical trial using simultaneous PET/fMRI imaging.

Part 1

Comment by Dr. Krishna Kumari Challa on November 8, 2023 at 10:08am

Contraceptive Pills Have a strange Effect on The Fear-Promoting Area of The Brain

Scientists have found a possible link between using oral contraceptives and changes in parts of the brain that process fear. The findings may help explain fear-related mechanisms that disproportionately affect women. Hormonal changes during a menstrual cycle are currently understood to affect the fear circuitry in the brain. So researchers looked into the effects of combined oral contraceptive (COC) use to learn more about the relationship between sex hormones our bodies make naturally and synthetic versions of those hormones. This effect appeared to be reversible. A comparison with those who stopped using contraceptives or those who had never used contraceptives indicated this physiological change didn't seem to be lasting. To be clear, these are just associations, and there are no known negative effects linked to the change in size of certain brain regions. But the authors think it could be worth exploring further. This part of the prefrontal cortex is thought to sustain emotion regulation, such as decreasing fear signals in the context of a safe situation. The result may represent a mechanism by which combined OCs could impair emotion regulation in women. Researchers found levels of both natural and synthetic sex hormones were linked to changes in the size and thickness of the vmPFC compared to the same anatomy in men. However, only women who were currently using oral contraceptives had a thinner vmPFC than that in men. The researchers also found the structure in a fear-promoting brain region – the dorsal anterior cingulate cortex (dACC) – varied between men and women. This was noticeable regardless of COC use, emphasizing one way naturally-produced sex hormones can influence brain structure. Given the results that men have smaller dACC volume than women and thicker vmPFC than COC users, these findings may represent structural vulnerabilities to psychopathologies that predominantly affect women.

https://www.frontiersin.org/articles/10.3389/fendo.2023.1228504/full

Comment by Dr. Krishna Kumari Challa on November 8, 2023 at 8:54am

The cell's 'read–write' mechanism: Researchers uncover how instructions for gene expression are relayed

The "read–write" mechanism by which cells replicate and use chemical instructions for expressing genes has been uncovered by  researchers. The quality and quantity of gene expression correlates not only with instructions by transcription factors but also with chemical modifications to the various histone proteins, which provide a scaffold for DNA in the chromosomes.

Scientists have long argued whether these modifications to histones are the epigenetic cause for activating gene expression. And, if that is the case, how they activate gene expression and are maintained during the process of mitosis, in which a cell divides into two daughter cells.

Researchers now have developed an experimental technology that allowed them to generate histones with acetylations at defined sites. They then monitored how p300/CBP interacts with and acetylates a nucleosome containing these selectively acetylated human histones.

The researchers found that p300/CBP recognizes and binds to specific acetylation marks on the H3–H4 complex. The enzyme then replicates acetylation marks to unacetylated sites of H3–H4, while also transcribing them from H3–H4 to H2B–H2A within the same nucleosome. Since this newly acetylated H2B–H2A complex is more likely to be stripped from the nucleosome, a model emerges in which it finally instructs which genes to be transcribed by the cellular transcription machinery. These results provide an unprecedented glimpse into how p300/CBP inherits acetylation marks to newly divided cells and utilizes those marks epigenetically for gene expression.

Masaki Kikuchi et al, Epigenetic mechanisms to propagate histone acetylation by p300/CBP, Nature Communications (2023). DOI: 10.1038/s41467-023-39735-4

Comment by Dr. Krishna Kumari Challa on November 8, 2023 at 8:32am

How global warming shakes the Earth: Seismic data show ocean waves gaining strength as the planet warms

As oceans waves rise and fall, they apply forces to the sea floor below and generate seismic waves. These seismic waves are so powerful and widespread that they show up as a steady thrum on seismographs, the same instruments used to monitor and study earthquakes.

That wave signal has been getting more intense in recent decades, reflecting increasingly stormy seas and higher ocean swell. In a new study in the journal Nature Communications, researchers tracked that increase around the world over the past four decades. These global data, along with other ocean, satellite and regional seismic studies, show a decadeslong increase in wave energy that coincides with increasing storminess attributed to rising global temperatures.

 Richard C. Aster et al, Increasing ocean wave energy observed in Earth's seismic wavefield since the late 20th century, Nature Communications (2023). DOI: 10.1038/s41467-023-42673-w

Comment by Dr. Krishna Kumari Challa on November 8, 2023 at 8:21am

The story of a teenage boy who swallowed 21 disc magnets

Doctors at Guthrie Healthcare System, in Sayre, Pennsylvania, have documented a case of a teenage boy who swallowed 21 disc magnets. In their paper published in BMJ Case Reports, the medical team describes how they found the magnets, removed them, and cared for the boy afterward.

Prior research and anecdotal evidence by doctors and other medical personnel has shown that swallowing magnets can be harmful. Their magnetic field and caustic properties can lead to damage in the digestive tract.

In this new study, the researchers report that a teenage boy was transferred to their facility from another hospital with metal objects of some kind in his stomach. When asked, the boy told the medical staff at both hospitals that he did not know how the objects could have wound up in this stomach. X-rays and a CT scan showed the presence of multiple metallic items. An initial procedure involved removing three small discs that had become embedded in the stomach wall using forceps and a surgical net. After removal, the doctors determined that the metal objects were small disc magnets. Three more of the magnets had become embedded in the walls of the large intestine—notably, there were also signs that the wound caused by the discs had led to decay of intestinal tissue. Further investigation showed that there were another 15 magnets embedded in various parts of both the large and small intestine, most of which required surgery for removal.

The surgeon noted that some of the magnets had begun to create holes in the intestinal walls. The case study team notes that the dangers of ingesting magnets are well known. Instead of passing harmlessly through the digestive tract, they become embedded in the walls of organs, causing tissue decay.

They also note that that the boy in their case study was lucky in the sense that pain caused by the magnets had brought him to the hospital before any of the magnets had time to burrow all the way through organ walls. Leakage of material from the stomach or intestines into other parts of the body can be deadly due to infection.

Simona Maksimyan et al, Clinical course and management of an unknown multiple-magnet ingestion in a teenage male, BMJ Case Reports (2023). DOI: 10.1136/bcr-2023-256418

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