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Comment by Dr. Krishna Kumari Challa yesterday

How a slender, snake-like robot could give doctors new ways to save lives

Researchers are building very slender, flexible and extensible robots, a few millimeters in diameter, for use in surgery and industry. You might call it "zoobotics."

Unlike humanoid robots, so-called continuum robots feature long, limbless bodies—not unlike a snake's—that allows them to access difficult-to-reach places.

Consider a neurosurgeon who needs to remove a brain tumor. Using a traditional, rigid surgical tool, the surgeon has to reach the cancerous mass by following a straight path into the brain, and risk poking through—and damaging—vital tissue.

Roboticists envisions a day when one of her snake-like robots, guided by a surgeon, would be able to take a winding path around the vital tissue but still reach the precise surgical site. Previously inoperable brain tumors might suddenly become operable.

It could revolutionize surgery. So they are also developing a more advanced generation of continuum robots that are equipped with sensors and can partially steer themselves. A surgeon would have to operate the robot remotely with a computer, but the robot would know how to avoid obstacles and recognize its destination. A surgeon could deploy one of these robots to collect a tissue sample from the abdomen, for instance, or inject a cancer drug directly into a tumor in the lungs.

There are uses outside the human body, too. A continuum robot could slide through the interior of a jet engine, inspecting it for damage. 

https://techxplore.com/news/2022-08-slender-snake-like-robot-doctor...

Comment by Dr. Krishna Kumari Challa yesterday

Matter at extreme conditions of very high temperature and pressure turns out to be remarkably simple and universal

Scientists at Queen Mary University of London have made two discoveries about the behavior of "supercritical matter"—matter at the critical point where the differences between liquids and gases seemingly disappear.
While the behavior of matter at reasonably low temperature and pressure was well understood, the picture of matter at high temperature and pressure was blurred. Above the critical point, differences between liquids and gases seemingly disappear, and the supercritical matter was thought to become hot, dense and homogeneous.

The researchers believed there was new physics yet to be uncovered about this matter at the supercritical state.

By applying two parameters—the heat capacity and the length over which waves can propagate in the system, they made two key discoveries. First, they found that there is a fixed inversion point between the two where matter changes its physical properties—from liquid-like to gas-like. They also found that this inversion point is remarkably close in all systems studied, telling us that the supercritical matter is intriguingly simple and amenable to new understanding.

As well as fundamental understanding of the states of matter and the phase transition diagram, understanding supercritical matter has many practical applications; hydrogen and helium are supercritical in gas giant planets such as Jupiter and Saturn, and therefore govern their physical properties. In green environmental applications, supercritical fluids have also proved to be very efficient at destroying hazardous wastes, but engineers increasingly want guidance from theory in order to improve efficiency of supercritical processes.

The asserted universality of the supercritical matter opens a way to a new physically transparent picture of matter at extreme conditions. This is an exciting prospect from the point of view of fundamental physics as well as understanding and predicting supercritical properties in green environmental applications, astronomy and other areas.

C. Cockrell et al, Double universality of the transition in the supercritical state, Science Advances (2022). DOI: 10.1126/sciadv.abq5183. www.science.org/doi/10.1126/sciadv.abq5183

Comment by Dr. Krishna Kumari Challa on Friday

Climate change and extreme heat are making us more anxious

Globally, heat waves have become an increasingly frequent summer affair, as much of the world faces extremely high temperatures. The rising frequency and intensity of heat waves can trigger various forms of emotional distress affecting people's mental health. One such emerging form of distress is eco-anxiety, which is defined by the American Psychological Association as the chronic fear of environmental doom that comes from observing climate change. In other words, people are worried about what a changing planet means for them and future generations. According to a landmark survey on eco-anxiety, 68% of adults reported experiencing "at least a little eco-anxiety" and 48% of young people report that climate change negatively affects their daily life and functioning. These worries are normal and even rational. We are connected to the land, air and water around us. So when our environments change, a primal sadness and worry is perfectly appropriate and perhaps even advantageous for survival. For millennia, people have relied on their ability to monitor, adapt to and migrate within their environment in order to survive. However, what we're facing with climate change is a whole new level of change. As highlighted by last year's IPCC report, the evidence showing that climate change causes greater frequency and intensity of extreme heat events is more certain than any other documented effect of climate change. Unfortunately, the same report predicts that global temperatures will continue to rise and their effects will worsen. It remains unclear what treatments and prevention strategies for eco-anxiety may be most effective, as public health and therapeutic research in this area is an emerging field. However, one thing is for certain: none of us can fix climate change, at least not alone. Climate change is a collective problem, not an individual one. Mitigating and adapting to it will require investments to build happier and healthier communities that will ensure that during extreme heat and other weather events people are not left to fend for themselves.

https://theconversation.com/climate-change-and-extreme-heat-are-mak...

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Comment by Dr. Krishna Kumari Challa on Friday

Nanoparticles train immune cells to fight cancer

Scientists in the department of Advanced Organ Bioengineering and Therapeutics (Faculty of S&T, TechMed Centre) recently published a novel cancer immune therapy in the scientific journal Nature Communications. In their research, scientists developed newly designed nanoparticles which can target the body's immune cells to turn them against cancer.

In cancer research, it has been increasingly known that tumor cells can change the alliance of some specific macrophages to help the tumor grow. "Macrophages are cells that act like the vacuum cleaners of your immune system. Normally they catch intruders and destroy them, but tumor cells can hijack these cells to help them spread throughout the body.

Scientists now designed nanoparticles that train these tumor-supporting "bad" macrophages into cells that will fight tumors. However, these tiny (100–200 nanometer diameter) cell-like structures first have to find the macrophages before they can start the training. 

To solve this challenge, the researchers had to alter the nanoparticles. The nanoparticles consist of a double layer of specific lipids (phospholipids) called nanoliposomes. These lipids have long tails that like to stick together in between the double layer. Researchers replaced some of the lipids to ones with a slightly shorter charged tail that can 'flip' to the outer surface. The bad macrophages can recognize these flipped tails and then eat up the whole particle.

When scientists knew how to target the bad macrophages, it became time to train them into fighting the tumor again. The researchers added a small component of the bacterial cell wall, which can train macrophages, to the "tail-flipping" nanoliposomes in the double layer wall of these nanoparticles. These molecules are then also taken up by the bad macrophages which subsequently train them to kill cancer cells. Targeting this compound this way prevents it from being recognized by the wrong cells and thus prevents damage to other parts of the body.

In the publication, the researchers not only show that the hijacked macrophages can be retrained to fight the cancer cells again, inhibiting the tumor growth by 70% in breast tumor mouse models. In the mice, the therapy prevented metastasis, the ability of cancer cells to spread through the body. The trained macrophages prevented the tumor cells from "preparing" lung tissue to host tumor cells—a process before metastasis. When a tumor cell arrived in the lungs, the tissue wasn't ready and the tumor cell couldn't start a new tumor.

 Praneeth R. Kuninty et al, Cancer immune therapy using engineered 'tail-flipping' nanoliposomes targeting alternatively activated macrophages, Nature Communications (2022). DOI: 10.1038/s41467-022-32091-9

Comment by Dr. Krishna Kumari Challa on Friday

Bioengineered cornea restores sight to the blind and visually impaired

Researchers and entrepreneurs have developed an implant made of collagen protein from pig's skin, which resembles the human cornea. In a pilot study, the implant restored vision to 20 people with diseased corneas, most of whom were blind prior to receiving the implant. The study has been published in Nature Biotechnology. The promising results bring hope to those suffering from corneal blindness and low vision by providing a bioengineered implant as an alternative to the transplantation of donated human corneas, which are scarce in countries where the need for them is greatest.

The results show that it is possible to develop a biomaterial that meets all the criteria for being used as human implants, which can be mass-produced and stored up to two years and thereby reach even more people with vision problems. This gets us around the problem of shortage of donated corneal tissue and access to other treatments for eye diseases.

The cornea consists mainly of the protein collagen. To create an alternative to human cornea, the researchers used collagen molecules derived from pig skin that were highly purified and produced under strict conditions for human use. The pig skin used is a byproduct of the food industry, making it easy to access and economically advantageous. In the process of constructing the implant, the researchers stabilized the loose collagen molecules forming a robust and transparent material that could withstand handling and implantation in the eye. While donated corneas must be used within two weeks, the bioengineered corneas can be stored for up to two years before use.

 Mehrdad Rafat, Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts, Nature Biotechnology (2022). DOI: 10.1038/s41587-022-01408-w. www.nature.com/articles/s41587-022-01408-w

Comment by Dr. Krishna Kumari Challa on Friday

Study of OTC supplements shows some have very high levels of levodopa, which can lead to paranoia

A team of researchers  has found that over-the-counter supplements that are advertised as containing extracts from Mucuna pruriens, a type of bean that contains levodopa, sometimes contain high levels of levodopa. In their paper published in the journal JAMA Neurology, the group describes testing the levels of levodopa in several Mucuna pruriens–based supplements.

Levodopa (known more commonly as L-DOPA) is a type of amino acid that is commonly found in plants and animals. In humans, it serves as a precursor to several types of neurotransmitters, one of which is dopamine. In 1969, researchers discovered that giving L-DOPA to patients with Parkinson's disease could reduce their symptoms; therefore, it is widely used today. Prior research has also found that many patients with Parkinson's disease believe that higher doses of L-DOPA will further improve their condition, but doctors do not agree. Still, some people with the disease buy over-the-counter supplements containing Mucuna pruriens extracts because research has shown the beans contain L-DOPA. In addition to overriding established medical advice, taking such supplements can have negative effects on patients, such as the development of paranoia. In this new effort, the researchers sought to learn more about Mucuna pruriens supplements—specifically, the amount of levodopa they contain. They purchased 16 bottles of the supplements and tested them. They found that the supplements all had different amounts of levodopa and that the amounts did not match what were listed on the labels. They also found some of the supplements had more levodopa in them than prescription medications. The researchers suggest their findings should be a warning to Parkinson's patients—they have no way of knowing how much levodopa they are consuming if they take such supplements, which can wreak havoc with the treatment prescribed by their doctor. The researchers note that some people who do not have Parkinson's disease also purchase and consume the supplements, which can lead to paranoia, agitation, impulse control and sometimes psychosis. 

Pieter A. Cohen et al, Levodopa Content of Mucuna pruriens Supplements in the NIH Dietary Supplement Label Database, JAMA Neurology (2022). DOI: 10.1001/jamaneurol.2022.2184

Comment by Dr. Krishna Kumari Challa on Thursday

Rainwater unsafe to drink due to chemicals: study

Rainwater everywhere on the planet is unsafe to drink due to levels of toxic chemicals known as PFAS that exceed the latest guidelines, according to a new study by scientists.

Commonly known as 'forever chemicals' because they disintegrate extremely slowly, PFAS (per- and polyfluoroalkyl substances) were initially found in packaging, shampoo or makeup but have spread to our entire environment, including water and air.

There is nowhere on Earth where the rain would be safe to drink, according to the measurements that scientists have taken now.

Even in Antarctica or the Tibetan plateau, the levels in the rainwater are above the drinking water guidelines that the US EPA (Environmental Protection Agency) proposed.

According to some studies, exposure can also lead to problems with fertility, development delays in children, increased risks of obesity or certain cancers (prostate, kidney and testicular), an increase in cholesterol levels.
—Planet 'irreversibly contaminated'—

We have made the planet inhospitable to human life by irreversibly contaminating it now so that nothing is clean anymore. And to the point that's it's not clean enough to be safe.

We have crossed a planetary boundary. And we have to learn to live with it.

 Per- and polyfluoroalkyl substances (PFAS) define a new planetary boundary for novel entities that has been exceeded, Environmental Science & Technology (2022). DOI: 10.1021/acs.est.2c02765

Comment by Dr. Krishna Kumari Challa on Thursday

Methane satellites find landfills with the same climate impact as several hundred thousand cars

Methane is almost thirty times more powerful as a greenhouse gas than CO₂. Researchers from SRON Netherlands Institute for Space Research therefore scan the entire globe for large methane leaks. A landfill in Buenos Aires turns out to emit tens of tons of methane per hour, comparable to the climate impact of one and a half million cars. They also detect large emissions from landfills in India and Pakistan, identifying new low-hanging fruit in the battle against climate change. The work was published on August 10 in Science Advances.

Methane is the second largest anthropogenic contributor to the greenhouse effect, after CO₂. This is due to its large global warming potential over 100 years (GWP-100). Methane is almost 30 times more potent per ton as a greenhouse gas than CO₂. When methane is released through human activity—by oil installations, coal mines, cattle sheds or landfills—it can be made less harmful by flaring it and thereby converting it to CO₂. Even better, if you capture it, you can put it to good use in boilers or stoves. Researchers from SRON Netherlands Institute for Space Research have now used satellite data to locate a number of landfills that are low-hanging fruit in the fight against climate change. Four landfills in Argentina, India and Pakistan emit several or even tens of tons of methane per hour.

 Buenos Aires, Delhi, Lahore and Mumbai stood out, with urban emissions on average twice as high as estimated in global inventories. The landfill in Buenos Aires emits 28 tons of methane per hour, comparable to the climate impact of 1.5 million cars. The three other landfills are responsible for, respectively, three, six and 10 tons of methane per hour, which still amounts to the impact of 130,000 to 500,000 cars.

Methane is odorless and colorless, so leaks are notoriously difficult to detect. But satellites are ideally suited for this. Landfills are super-emitters that pump large amounts of methane into the atmosphere. That is painful to watch because you can solve it with relatively little effort. You could, for example, separate and compost the organic waste, which would drastically reduce methane production. And even in the case of mixed waste, you can still collect or flare the methane produced. Methane has a lifetime of only about 10 years in the atmosphere, so if we act now, we will quickly see results in the form of less global warming.

Joannes D. Maasakkers, Daniel J. Varon, Aldís Elfarsdóttir, Jason McKeever, Dylan Jervis, Gourav Mahapatra, Sudhanshu Pandey, Alba Lorente, Tobias Borsdorff, Lodewijck R. Foorthuis, Berend J. Schuit, Paul Tol, Tim A. van Kempen, Richard van Hees, Ilse Aben, 'Using satellites to uncover large methane emissions from landfills', Science Advances, 2022. science.org/doi/10.1126/sciadv.abn9683

Comment by Dr. Krishna Kumari Challa on Thursday

Watch tiny electromechanical robots that are faster than cheetahs for their size

Comment by Dr. Krishna Kumari Challa on August 9, 2022 at 9:24am

Mystery cells that create blood stem cells in mammals identified

Imagine if one day blood transfusions from strangers were not needed because they could be produced from cells that line your own blood vessels' cells.

While that day is still some years off, medical researchers at UNSW Sydney have made an important first step by identifying—in mice—a mechanism that is used naturally in mammals to make blood from cells that line blood vessels.

It was already known that a process termed "endothelial to hematopoietic transition" takes place in mammalian embryos, whereby cells lining blood vessels (endothelial cells) change into blood stem cells.

But the identity of the cells that regulate this process had up until now been a mystery.

In a paper published recently in the journal Nature Cell Biology, a team of researchers describe how they solved this puzzle by identifying the cells in the embryo that can convert adult endothelial cells into blood stem cells. The cells—known as "Mesp1-derived PDGFRA+ stromal cells"—reside underneath the aorta.

While more research is needed before this can be translated into clinical practice, the discovery could be an important step in regenerative medicine by providing a potential new tool to generate engraftable hematopoietic stem cells.

Vashe Chandrakanthan et al, Mesoderm-derived PDGFRA+ cells regulate the emergence of hematopoietic stem cells in the dorsal aorta, Nature Cell Biology (2022). DOI: 10.1038/s41556-022-00955-3

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