Comment

Comment by Dr. Krishna Kumari Challa 15 hours ago

First fetus-to-fetus transplant demonstrated in rats

The tissue developed into functioning kidneys and produced urine.

Surgeons in Japan have transplanted kidney tissue from one rat fetus to another, while the recipient was still in its mother's womb. Study lead Takashi Yokoo, a nephrologist at Jikei University School of Medicine in Tokyo, says the surgery is the first step to one day transplanting fetal pig kidneys into human fetuses that develop without functioning kidneys.

Transplanting an organ before birth could allow it to grow and develop with the fetus, so that the organ is functioning at birth and has less risk of rejection.

The recipient pups were born as normal after 22 days, according to a preprint (not peer reviewed). Blood vessels from the host fetus grew inside the donated tissue, lowering the risk of rejection. 

https://www.biorxiv.org/content/10.1101/2024.04.15.589452v1

https://www.nature.com/articles/d41586-024-01152-y?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa 15 hours ago

So what should you do if you come across a green cloth book from the 19th century? First, don't be overly concerned. You would probably have to eat the entire book before you'd suffer from severe arsenic poisoning. However, casual exposure to copper acetoarsenite, the compound in the green pigment, can irritate the eyes, nose and throat.

It is more of a concern for folks who may regularly handle these books where frequent contact could result in more serious symptoms. Therefore, anyone who suspects they might be handling a Victorian-era book with an emerald green binding is advised to wear gloves and avoid touching their face. Then clean all surfaces afterwards.

To aid with the identification of these potentially hazardous books, the Poisonous Book Project has incorporated crowd-sourced data into their research. The researchers now distribute bookmarks that feature safety warnings and showcase various shades of emerald green to aid their identification. As a result, they have now identified over 238 arsenic editions from across the globe.

https://theconversation.com/many-old-books-contain-toxic-chemicals-...

Part 3

**

Comment by Dr. Krishna Kumari Challa 15 hours ago

The harmful effects of these pigments have even been implicated in Napoleon's death from stomach cancer. Napoleon was particularly keen on the new green colors, so much so that he ordered his dwelling on St Helena, where he was exiled, be painted in his favorite color.

The theory that the arsenic in the walls contributed to his death is supported by the high levels of arsenic detected in samples of his hair. Despite the clear link between the green pigments and health issues, toxic wallpapers continued to be produced until the late 19th century.
Green isn't the only color to worry about, however. Red is also of concern. The brilliant red pigment vermilion was formed from the mineral cinnabar, also known as mercury sulfide. This was a popular source of red paint dating back thousands of years. There is even evidence that neolithic artists suffered from mercury poisoning. Vermilion red sometimes appears on the marbled patterns on the inside of book covers.

Yellow has also caught the eye of the poisonous book project. In this case, the culprit is lead chromate. The bright yellow of lead chromate was a favorite with painters, not least Vincent van Gogh, who used it extensively in his most famous series of paintings: Sunflowers. For the Victorian-era bookbinders, lead chromate allowed them to create a range of colors from greens (achieved by mixing chrome yellow with Prussian blue) to yellows, oranges and browns.

Both lead and chromium are toxic. But yellow books are less of a concern than green and red. Lead chromate is not particularly soluble, making it difficult to absorb. It is, in fact, still a widely used pigment.
Part 2

Comment by Dr. Krishna Kumari Challa 15 hours ago

Many old books contain toxic chemicals

In our modern society, we rarely consider books to be dangerous items. However, certain books contain elements so hazardous that they require scrutiny before being placed on the shelves of public libraries, bookstores or even private homes.

The Poisonous Book Project, a collaborative research project between Winterthur Museum, Garden & Library and the University of Delaware, is dedicated to cataloging such books. Their concern is not with the content written on the pages, but with the physical components of the books themselves—specifically, the colors of the covers.
The project recently influenced the decision to remove two books from the French national library. The reason? Their vibrant green cloth covers raised suspicions of containing arsenic.

This concern is rooted in historical practices in bookbinding. During the 19th century, as books began to be mass produced, bookbinders transitioned from using expensive leather covers to more affordable cloth items. To attract readers, these cloth covers were often dyed in bright, eye-catching colours.
One popular pigment was Scheele's green, named after Carl Wilhelm Scheele, a German-Swedish chemist who in 1775 discovered that a vivid green pigment could be produced from copper and arsenic. This dye was not only cheap to make, it was also more vibrant than the copper carbonate greens that had been used for over a century.
Paris green, 's much more durable. It was quickly adopted for use in various items, including book covers, clothing, candles and wallpaper.
These pigments, however, had a significant drawback: they degraded easily, releasing poisonous and carcinogenic arsenic. The frequent reports of green candles poisoning children at Christmas parties, factory workers tasked with applying paint to ornaments convulsing and vomiting green water and warnings of poisonous ball dresses raised serious concerns about the safety of these green dyes.
Part 1

Comment by Dr. Krishna Kumari Challa yesterday

Physicists overcome two key operating hurdles in fusion reactions

A team of physicists has devised a way to overcome two key hurdles standing in the way of using fusion as a general power source.

In their paper published in the journal Nature, the group describes how they devised a way to raise the density of the plasma in their reactor while also keeping it stable.

Scientists at various sites around the world have been working for several years to figure out how to use fusion reactions to create electricity for general use—thereby freeing the world from using coal and gas fired power plants that spew greenhouse gases into the atmosphere. But it has been a long and difficult road.

It was just in the past couple of years that researchers were able to show that a fusion reaction could be made to sustain itself, and that more power could be produced than was input into such a system.

The next two hurdles to overcome are increasing the density of the plasma in the reactor and then containing it for extended periods of time—long enough for it to be useful for producing electricity. In this new study, the research team has devised a way to do both in a tokamak chamber.

To contain the plasma as its density was increased, the team used additional magnets and bursts of deuterium where needed. They also allowed for higher densities at the core than near the edges, helping to ensure the plasma could not escape. They held it in that state for 2.2 seconds, long enough to prove that it could be done.

They also found that during that short time span, the average density in the reactor was 20% over the Greenwald limit—a theoretical barrier that had been predicted to mark the point at which adding pressure would escape the magnetic field holding the plasma in place.

They also found that the stability of the plasma was H_98y2 above 1, which means that the experiment was successful.

The research team acknowledges that their experiment was done in a very small reactor—one with a diameter of just 1.6 meters. For such an achievement to be considered fully successful, it will have to be done in a much larger reactor, such as the one currently under construction in France, which will have a diameter of 6.2 meters.

S. Ding et al, A high-density and high-confinement tokamak plasma regime for fusion energy, Nature (2024). DOI: 10.1038/s41586-024-07313-3

Comment by Dr. Krishna Kumari Challa yesterday

Researchers  find brown fat's 'off-switch'

Brown fat, also known as brown adipose tissue (BAT), is a type of fat in our bodies that's different from the white fat around our belly and thighs that we are more familiar with. Brown fat has a special job—it helps to burn calories from the foods that we eat into heat, which can be helpful, especially when we're exposed to cold temperatures like during winter swimming or cryotherapy.

For a long time, scientists thought that only small animals like mice and newborns had brown fat. But new research shows that a certain number of adults maintain their brown fat throughout life. Because brown fat is so good at burning calories, scientists are trying to find ways to activate it safely using drugs that boost its heat-producing abilities.

A new study  has found that brown fat has a previously unknown built-in mechanism that switches it off shortly after being activated. This limits its effectiveness as treatment against obesity. The team has now discovered a protein responsible for this switching-off process. It is called "AC3-AT."

Hande Topel et al, Cold-induced expression of a truncated Adenylyl Cyclase 3 acts as rheostat to brown fat function, Nature Metabolism (2024). DOI: 10.1038/s42255-024-01033-8

**

Comment by Dr. Krishna Kumari Challa yesterday

Using existing data from various sources, including measurements of fluid movements related to oil and gas extraction and water injections for geothermal energy, the team found that the current fluid movement rates induced by human activities are higher compared to how fluids moved before human intervention.

As human activities like carbon capture and sequestration and lithium extraction ramp up, the researchers also predicted how these activities might be recorded in the geological record, which is the history of Earth as recorded in the rocks that make up its crust.

Human activities have the potential to alter not just the deep subsurface fluids but also the microbes that live down there.
As fluids move around, microbial environments may be altered by changes in water chemistry or by bringing new microbial communities from Earth's surface to the underground.

For example, with hydraulic fracturing, a technique that is used to break underground rocks with pressurized liquids for extracting oil and gas, a deep rock formation that previously didn't have any detectable number of microbes might have a sudden bloom of microbial activity.

There remain a lot of unknowns about Earth's deep subsurface and how it is impacted by human activities, and it's important to continue working on those questions, say the scientists.

Grant Ferguson et al, Acceleration of Deep Subsurface Fluid Fluxes in the Anthropocene, Earth's Future (2024). DOI: 10.1029/2024EF004496

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Human activities have an intense impact on Earth's deep subsurface fluid flow

The impact of human activities—such as greenhouse gas emissions and deforestation—on Earth's surface have been well-studied. Now, hydrology researchers  have investigated how humans impact Earth's deep subsurface, a zone that lies hundreds of meters to several kilometers beneath the planet's surface.

They looked at how the rates of fluid production with oil and gas compare to natural background circulation of water and showed how humans have made a big impact on the circulation of fluids in the subsurface.

In the future, these human-induced fluid fluxes are projected to increase with strategies that are proposed as solutions for climate change, according the study. Such strategies include: geologic carbon sequestration, which is capturing and storing atmospheric carbon dioxide in underground porous rocks; geothermal energy production, which involves circulating water through hot rocks for generating electricity; and lithium extraction from underground mineral-rich brine for powering electric vehicles.

Responsible management of the subsurface is central to any hope for a green transition, sustainable future and keeping warming below a few degrees.

With oil and natural gas production, there is always some amount of water, typically saline, that comes from the deep subsurface. The underground water is often millions of years old and acquires its salinity either from evaporation of ancient seawater or from reaction with rocks and minerals. For more efficient oil recovery, more water from near-surface sources is added to the salt water to make up for the amount of oil removed and to maintain reservoir pressures. The blended saline water then gets reinjected into the subsurface. This becomes a cycle of producing fluid and reinjecting it to the deep subsurface.

The same process happens in lithium extraction, geothermal energy production and geologic carbon sequestration, the operations of which involve leftover saline water from the underground that is reinjected.

Researchers showed that the fluid injection rates or recharge rates from those oil and gas activities is greater than what naturally occurs .

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

Research shows 'profound' link between dietary choices and brain health

A recent study published in Nature Mental Health shows that a healthy, balanced diet is linked to superior brain health, cognitive function and mental well-being. The study, involving researchers at the University of Warwick, sheds light on how our food preferences not only influence physical health but also significantly impact brain health.

The dietary choices of a large sample of 181,990 participants from the UK Biobank were analyzed against and a range of physical evaluations, including cognitive function, blood metabolic biomarkers, brain imaging, and genetics—unveiling new insights into the relationship between nutrition and overall well-being.

The food preferences of each participant were collected via an online questionnaire, which the team categorized into 10 groups (such as alcohol, fruits and meats). A type of AI called machine learning helped the researchers analyze the large dataset.

A balanced diet was associated with better mental health, superior cognitive functions and even higher amounts of gray matter in the brain—linked to intelligence—compared with those with a less varied diet.

The study also highlighted the need for gradual dietary modifications, particularly for individuals accustomed to highly palatable but nutritionally deficient foods. By slowly reducing sugar and fat intake over time, individuals may find themselves naturally gravitating towards healthier food choices.

Genetic factors may also contribute to the association between diet and brain health, the scientists think, showing how a combination of genetic predispositions and lifestyle choices shape well-being.

 Ruohan Zhang et al, Associations of dietary patterns with brain health from behavioral, neuroimaging, biochemical and genetic analyses, Nature Mental Health (2024). DOI: 10.1038/s44220-024-00226-0

Comment by Dr. Krishna Kumari Challa yesterday

Study suggests that stevia is the most brain-compatible sugar substitute

Given the known risks of consuming high amounts of sugar, today many people are looking for alternative sweeteners that produce a similar taste without prompting significant weight gain and causing other health issues. While research suggests that the brain can tell the difference between different sweet substances, the neural processes underlying this ability to tell sweeteners apart remain poorly understood.

Researchers recently carried out a study aimed at better understanding what happens in the brain of mice when they are fed different types of sweeteners. Their findings, published in Neuroscience Research, suggest that the response of neurons to sucrose and stevia is similar, suggesting that stevia could be an equally pleasant but healthier sugar substitute.

Stevia is a sweet sugar substitute that is about 50 to 300 times sweeter than sugar. It is extracted from the leaves of Stevia rebaudiana, a plant native to areas of Paraguay and Brazil in the southern Amazon rainforest.The active compounds in stevia are steviol glycosides (mainly stevioside and rebaudioside). Stevia is heat-stable, pH-stable, and not fermentable. Humans cannot metabolize the glycosides in stevia, and therefore it has zero calories. Its taste has a slower onset and longer duration than that of sugar, and at high concentrations some of its extracts may have an aftertaste described as licorice-like or bitter. Stevia is used in sugar- and calorie-reduced food and beverage products as an alternative for variants with sugar.

Interestingly, the team's recordings revealed that compared to other sugar substitutes considered as part of this study, stevia induced activity in the PVT that more closely resembled that elicited by sugar intake. This suggests that stevia is the most "brain compatible" among most widely used sugar alternatives, most closely mirroring the perceived taste of sugar.

Shaolei Jiang et al, Neuronal activity in the anterior paraventricular nucleus of thalamus positively correlated with sweetener consumption in mice, Neuroscience Research (2024). DOI: 10.1016/j.neures.2024.02.002

• ‹ Previous
• 1
• 2
• 3
• …
• 846
• Next ›
• Page