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Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 11:47am

Why coffee beans taste different

Differences in the flavours of Arabica coffee varieties aren’t because of variations in individual genes. Rather, they seem to be mainly the result of wholesale swapping, deletion and rearrangement.... The most complete sequencing yet of Coffea arabica’s genome reveals that the levels of single-‘letter’ variations in the plant’s DNA “are anywhere from 10 to 100 times lower than any other species”, says plant geneticist and study co-author Michele Morgante.

Nature
 Nature Communications paper

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Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 11:43am

Researchers observe tiny pseudoscorpion riding on a scorpion

Researchers recently  documented the first observation of phoresy involving a myrmecophile pseudo-scorpion on a myrmecophile scorpion.

Phoresy, a well-established phenomenon among pseudoscorpions, involves their attachment to hosts for dispersal into new environments. Documented instances of phoresy include pseudoscorpions attaching themselves to various hosts, ranging from mammals and birds to different insect orders and even other arachnids.

The study focused on pseudoscorpions belonging to an endemic Withiidae species, Nannowithius wahrmani, observed clinging onto the endemic scorpion species Birulatus israelensis in Israel. The research paper, titled "Hitching a ride on a scorpion: the first record of phoresy of a myrmecophile pseudoscorpion on a myrmecophile scorpion," is published in Arachnologische Mitteilungen: Arachnology Letters.

Sharon Warburg et al, Hitching a ride on a scorpion: the first record of phoresy of a myrmecophile pseudoscorpion on a myrmecophile scorpion, Arachnologische Mitteilungen: Arachnology Letters (2024). DOI: 10.30963/aramit6605

Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 10:05am

Co-stimulatory signaling domains have been added to newer generations of CAR T cells to improve their ability to produce more T cells after infusion and survive longer in the circulation.

Credit: Brentjens R, et al. “Driving CAR T cells forward.” Nat Rev Clin Oncol. 2016 13, 370–383.

Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 10:04am

Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 10:03am

Difference between T cells and CAR T cells

CAR T cells are made by collecting T cells from the patient and re-engineering them in the laboratory to produce proteins on their surface called chimeric antigen receptors, or CARs. The CARs recognize and bind to specific proteins, or antigens, on the surface of cancer cells.

These receptors are synthetic molecules, they don't exist naturally.

After the revamped T cells are “expanded” into the millions in the laboratory, they’re then infused back into the patient. If all goes as planned, the CAR T cells will continue to multiply in the patient's body and, with guidance from their engineered receptor, recognize and kill any cancer cells that harbor the target antigen on their surfaces.

https://www.cancer.gov/about-cancer/treatment/research/car-t-cells#....

Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 9:55am

With modification, CAR T cells can attack senescent cells, leading to slower aging in mice

Researchers have discovered that T cells can be reprogrammed to fight aging, so to speak. Given the right set of genetic modifications, these white blood cells can attack another group of cells known as senescent cells. These cells are thought to be responsible for many of the diseases we grapple with later in life.

Senescent cells are those that stop replicating. As we age, they build up in our bodies, resulting in harmful inflammation. While several drugs currently exist that can eliminate these cells, many must be taken repeatedly over time.
As an alternative, scientists turned to a "living" drug called CAR (chimeric antigen receptor) T cells. They discovered CAR T cells could be manipulated to eliminate senescent cells in mice. As a result, the mice ended up living healthier lives. They had lower body weight, improved metabolism and glucose tolerance, and increased physical activity. All benefits came without any tissue damage or toxicity.
If we give it to aged mice, they rejuvenate. If we give it to young mice, they age slower. No other therapy right now can do this.
Perhaps the greatest power of CAR T cells is their longevity. The team found that just one dose at a young age can have lifelong effects. That single treatment can protect against conditions that commonly occur later in life, like obesity and diabetes.
T cells have the ability to develop memory and persist in your body for really long periods, which is very different from a chemical drug. With CAR T cells, you have the potential of getting this one treatment, and then that's it. For chronic pathologies, that's a huge advantage. Think about patients who need treatment multiple times per day versus you get an infusion, and then you're good to go for multiple years.
CAR T cells have been used to treat a variety of blood cancers, receiving FDA approval for this purpose in 2017. But this team is one of the first scientists to show that CAR T cells' medical potential goes even further than cancer.

Nature Aging (2024). DOI: 10.1038/s43587-023-00560-5

Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 9:50am

So they turned to the concept of high-entropy design to come up with a porous ceramic material that achieved a good balance between strength and heat resistance without the usual downsides.

High-entropy design focuses on the use of equal measures of multiple elements that can be used to create stronger, more heat-resistant and more stable components.

The researchers developed a material that achieved the demanding insulation and weight criteria for aerospace flight. Their new ceramic creation, which goes by the unassuming name 9PHEB—9-cation porous high-entropy diboride—provides "exceptional thermal stability" and "ultrahigh compressive strength," the researchers said.

"High-quality interfaces, characterized by strong bonding without defects or amorphous phases, can promote the rapid force transfer along the building block and to many other ones through connections upon loading, leading to a significant enhancement of mechanical strength," the report said.

 Zihao Wen et al, Ultrastrong and High Thermal Insulating Porous High‐Entropy Ceramics up to 2000 °C, Advanced Materials (2024). DOI: 10.1002/adma.202311870

Part 2

Comment by Dr. Krishna Kumari Challa on January 25, 2024 at 9:49am

Scientists announce breakthrough in hypersonic heat shield

In a giant leap for future hypersonic flight,  scientists have turned to multi-scale technology to develop a revolutionary new material that has achieved record high marks in tests for vital strength and thermal insulation properties.

The scientists say their porous ceramic creation opens the door to wider exploration in the fields of aerospace, chemical engineering and energy transfer and production.

For the first time, it is reported a multi-scale structure design and fast fabrication of … high-entropy ceramics via an ultrafast high-temperature synthesis technique that can lead to exceptional mechanical load-bearing capability and high thermal insulation performance," the researchers said in a paper published Jan. 2 in the journal Advanced Materials.

Scientists have long faced challenges in developing strong, lightweight materials boasting low-thermal conductivity that are critical, especially for hypersonic travel. Ceramic materials offer promise because they exhibit low thermal conductivity, high melting points and corrosion resistance, and they are also non-combustible.
But exploration projects at great depths below the Earth's surface as well as in outer space encounter extremely high temperatures and pressure. Traditional ceramic materials are insufficient in those instances.

Lightweight, porous materials offered low thermal transfer but that desirable property often came with a tradeoff—greater fragility.

In their report, "Ultrastrong and High Thermal Insulating Porous High-Entropy Ceramics up to 2000 °C," researchers stated, "It is imperative to find ways to simultaneously improve the mechanical strength and thermal insulation capacity of porous ceramics."
Part 1

Comment by Dr. Krishna Kumari Challa on January 24, 2024 at 6:44am

Membranes form boundaries in nearly all kinds of cells. Not only does a cell have an outer membrane that contains and protects the interior, but often there are other membranes inside, forming parts of organelles such as mitochondria and the Golgi apparatus. Understanding membranes is important to medical science, not least because proteins lodged in the cell membrane are frequent drug targets. Some membrane proteins are like gates that regulate what gets into and out of the cell.

The region near these membranes can be a busy place. Thousands of types of different molecules crowd each other and the cell membrane—and as anyone who has tried to push through a crowd knows, it can be tough going. Smaller molecules such as salts move with relative ease because they can fit into tighter spots, but larger molecules, such as proteins, are limited in their movements.

This sort of molecular crowding has become a very active scientific research topic, because it plays a real-world role in how the cell functions. How a cell behaves depends on the delicate interplay of the ingredients in this cellular "soup." Now, it appears that the cell membrane might have an effect too, sorting molecules near itself by size and charge.

How does crowding affect the cell and its behavior? How, for example, do molecules in this soup get sorted inside the cell, making some of them available for biological functions, but not others? The effect of the membrane could make a difference.

Marcel Aguilella-Arzo et al, Charged Biological Membranes Repel Large Neutral Molecules by Surface Dielectrophoresis and Counterion Pressure, Journal of the American Chemical Society (2024). DOI: 10.1021/jacs.3c12348. pubs.acs.org/doi/full/10.1021/jacs.3c12348

Comment by Dr. Krishna Kumari Challa on January 24, 2024 at 6:42am

Cells' electric fields keep nanoparticles at bay, scientists confirm

The humble membranes that enclose our cells have a surprising superpower: They can push away nano-sized molecules that happen to approach them. A team including scientists at the National Institute of Standards and Technology (NIST) has figured out why, by using artificial membranes that mimic the behavior of natural ones. Their discovery could make a difference in how we design the many drug treatments that target our cells.

The team's findings, which appear in the Journal of the American Chemical Society, confirm that the powerful electrical fields that cell membranes generate are largely responsible for repelling nanoscale particles from the surface of the cell.
This repulsion notably affects neutral, uncharged nanoparticles, in part because the smaller, charged molecules the electric field attracts crowd the membrane and push away the larger particles. Since many drug treatments are built around proteins and other nanoscale particles that target the membrane, the repulsion could play a role in the treatments' effectiveness.

The findings provide the first direct evidence that the electric fields are responsible for the repulsion.

This repulsion, along with the related crowding that the smaller molecules exert, is likely to play a significant role in how molecules with a weak charge interact with biological membranes and other charged surfaces.

This has implications for drug design and delivery, and for the behavior of particles in crowded environments at the nanometer scale.

Part 1

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