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Comment by Dr. Krishna Kumari Challa on April 20, 2023 at 11:17am

Nanoparticles provoke immune response against tumors but avoid side effects

Cancer drugs that stimulate the body's immune system to attack tumors are a promising way to treat many types of cancer. However, some of these drugs produce too much systemic inflammation when delivered intravenously, making them harmful to use in patients.

Researchers have now come up with a possible way to get around that obstacle. In a new study, they showed that when immunostimulatory prodrugs—inactive drugs that require activation in the body—are tuned for optimal activation timing, the drugs provoke the immune system to attack tumors without the side effects that occur when the active form of the drug is given.

The researchers designed prodrugs with bottlebrush-like structures based on a class of compounds called imidazoquinolines (IMDs). Mice treated with these bottlebrush prodrugs designed with optimized activation kinetics showed a significant reduction in tumor growth, with no side effects. The researchers hope that this approach could be used to boost immune system responses in cancer patients, especially when combined with other immunotherapy drugs or cancer vaccines.

Sachin Bhagchandani et al, Engineering kinetics of TLR7/8 agonist release from bottlebrush prodrugs enables tumor-focused immune stimulation, Science Advances (2023). DOI: 10.1126/sciadv.adg2239. www.science.org/doi/10.1126/sciadv.adg2239

Comment by Dr. Krishna Kumari Challa on April 20, 2023 at 11:10am

Stab-resistant fabric gains strength from carbon nanotubes, polyacrylate

Fabrics that resist knife cuts can help prevent injuries and save lives. But a sharp enough knife or a very forceful jab can get through some of these materials. Now, researchers report in ACS Applied Nano Materials that carbon nanotubes and polyacrylate strengthen conventional aramid to produce lightweight, soft fabrics that provide better protection. Applications include anti-stabbing clothing, helmets and insoles, as well as cut-resistant packaging.

Soft body armor is typically made from aramid, ultra-high-molecular-weight polyethylene, or carbon and glass fabrics. Their puncture resistance depends, in part, on the friction between yarn fibers within these materials. Up to a point, greater friction means greater protection. Manufacturers can boost friction by roughening the fiber surfaces, but that requires a complicated process, and product yield is low.

Alternatively, the bonding force between yarns can be enhanced by adding another component, such as a sheer thickening fluid (STF) or a polyurethane (PU) coating. But these composite fabrics can't simultaneously satisfy the requirements for thinness, flexibility and light weight. Researchers now  wanted to find another way to improve performance while satisfying these criteria.

The researchers tested a polyacrylate emulsion (PAE), STF and PU as coatings on aramid fabric. In simulated stabbing tests, aramid fabric coated with PAE outperformed the uncoated material used by itself or in combination with STF or PU. Carbon nanotubes are known to make composites tougher, and adding them to aramid/PAE further improved impact resistance. The research team says that's because the nanotubes created bridges between the fibers, thereby increasing friction. The nanotubes also formed a thin, protective network that dispersed stress away from the point of impact and helped prevent fiber disintegration. The new lightweight, flexible, puncture-resistant composite fabric could be useful in military and civilian applications, according to the researchers.

Wen-hua Cai et al, Polyacrylate and Carboxylic Multi-Walled Carbon Nanotube-Strengthened Aramid Fabrics as Flexible Puncture-Resistant Composites for Anti-Stabbing Applications, ACS Applied Nano Materials (2023). DOI: 10.1021/acsanm.3c00738

Comment by Dr. Krishna Kumari Challa on April 19, 2023 at 11:19am

The team tested the drug against the pathogenic bacteria Pseudomonas aeruginosa and Acinetobacter baumannii, which feature at the top of the World Health Organization's priority list. The treatment sequestered toxins released by the pathogens and disrupted their ability to communicate, reducing the formation of protective biofilms as explained in this short video:

While these experiments showed that the drug could effectively disarm these pathogens, the researchers also wanted to know if it could make them more vulnerable. Supplementing an antibiotic treatment with the new drug made the antibiotic effective at a lower dose. But more importantly, when the team treated bacteria with a combination of antibiotics and the new drug for two weeks, the bacteria didn't evolve resistance to the antibiotics, although they rapidly became resistant when exposed to the antibiotics alone.

This suggests that the new drug could be used to preserve the efficacy of the antibiotics we have left.

The drug interacts with part of the bacterial outer membrane, which is a strong barrier against antibiotics. The drug loosens the membrane and makes it more permeable. That means it's easier for antibiotics to get into the bacteria and kill them.

Having shown that the drug is effective against bacterial pathogens, the next step was to determine whether it could actually provide protection. To test that, human lung cells were exposed to toxins that cause inflammation and cellular damage. The drug directly sequestered the toxins and protected against inflammation and cellular damage. The researchers found similar protective results when mice were exposed to the toxins.

These findings open the door to an exciting new alternative to antibiotics, one that could potentially break the vicious cycle of antibiotic discovery and resistance. This treatment and others like it could provide the boost we need to keep ahead in our never-ending arms race with bacterial resistance.

 Christopher Jonkergouw et al, Repurposing host-guest chemistry to sequester virulence and eradicate biofilms in multidrug resistant Pseudomonas aeruginosa and Acinetobacter baumannii, Nature Communications (2023). DOI: 10.1038/s41467-023-37749-6

Part 2

Comment by Dr. Krishna Kumari Challa on April 19, 2023 at 11:16am

A potential treatment for multidrug-resistant bacteria

A new type of drug could provide a way to treat multidrug-resistant bacteria, according to a study published in Nature Communications. Instead of targeting the bacteria directly, the drug blocks key toxins involved in the infection process. This both reduces inflammation and makes the bacteria more vulnerable to antibiotics.

Antibiotics have been invaluable in the fight against bacterial infections, but bacteria are becoming more and more resistant to them. In the early days of antibiotics, bacteria took about 11 years on average to become resistant, but that figure has dropped to 2-3 years today. Many common bacterial infections are becoming resistant, and new antibiotics aren't being developed quickly enough to keep pace.

In 2019, 1.27 million deaths were directly attributable to antimicrobial resistance, and that number is expected to rise to 10 million per year in 2050. "We urgently need new tools to tackle these resistant infections. Despite this, no new antibiotics have been approved in decades, and there are just six currently under development that might sidestep resistance, only two of which target highly resistant bacteria.

A different approach would be to directly target the toxins and biofilms that pathogens use to establish the infection and cause inflammation, collectively called virulence factors. These virulence factors include small molecules that bacteria use to communicate and larger molecules that are part of their protective membrane. A drug that binds to these molecules could interfere with processes that are vital to the bacteria.

An international team led by researchers at Aalto went looking for drugs that could do just that. They found a good candidate after screening a library to identify molecules that interact with virulence factors but don't affect the bacteria's growth. Because the drug disarms the pathogen instead of killing it or halting its growth, this approach generates much weaker selection pressure for the development of resistant bacteria.

Part 1

Comment by Dr. Krishna Kumari Challa on April 19, 2023 at 10:03am

Quantum liquid becomes solid when heated!

Solids can be melted by heating, but in the quantum world it can also be the other way around: In a joint effort, an experimental team show how a quantum liquid forms supersolid structures through heating. The scientists obtained a first phase diagram for a supersolid at finite temperature.

Supersolids are a relatively new and exciting area of research. They exhibit both solid and superfluid properties simultaneously. In 2019, three research groups were able to demonstrate this state for the first time beyond doubt in ultracold quantum gases.

To explore the effect of thermal fluctuation, researchers developed and published in Nature Communications a theoretical model that can explain the experimental results and underlines the thesis that heating the quantum liquid can lead to the formation of a quantum crystal. The theoretical model shows that as the temperature rises, these structures can form more easily.

The surprising behavior, which contradicts our everyday observation, arises from the anisotropic nature of the dipole-dipole interaction of the strongly magnetic atoms of dysprosium.

 J. Sánchez-Baena et al, Heating a dipolar quantum fluid into a solid, Nature Communications (2023). DOI: 10.1038/s41467-023-37207-3

Comment by Dr. Krishna Kumari Challa on April 19, 2023 at 9:51am

Researchers develop carbon-negative concrete

A viable formula for a carbon-negative, environmentally friendly concrete that is nearly as strong as regular concrete has been developed by researchers.

In a proof-of-concept work, the researchers infused regular cement with environmentally friendly biochar, a type of charcoal made from organic waste, that had been strengthened beforehand with concrete wastewater. The biochar was able to suck up to 23% of its weight in carbon dioxide from the air while still reaching a strength comparable to ordinary cement.

The research could significantly reduce carbon emissions of the concrete industry, which is one of the most energy- and carbon-intensive of all manufacturing industries.

Zhipeng Li et al, Towards sustainable industrial application of carbon-negative concrete: Synergistic carbon-capture by concrete washout water and biochar, Materials Letters (2023). DOI: 10.1016/j.matlet.2023.134368

Comment by Dr. Krishna Kumari Challa on April 18, 2023 at 11:59am

Comment by Dr. Krishna Kumari Challa on April 18, 2023 at 9:48am

Dark Matter Matters

Comment by Dr. Krishna Kumari Challa on April 18, 2023 at 9:37am

Income rank linked to experience of physical pain, irrespective of whether in a rich or poor country, study suggests

A new study of worldwide polling data suggests that a person's income rank relative to their peers is linked to their experience of physical pain, with a lower income rank linked to a higher likelihood of experiencing pain. It is the first time such a relationship has been shown.

The study found the link to persist, to the same degree, irrespective of whether the person lives in a rich country or a poor country. Income rank is the position of an individual's absolute personal income amount in a list of those amounts ordered from lowest to highest. The higher the position in the list, the higher the income rank.

 Having less than others is physically painful: Income rank and pain around the world, Social Psychological and Personality Science (2023). DOI: 10.1177/19485506231167928

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Comment by Dr. Krishna Kumari Challa on April 18, 2023 at 8:54am

The Fight Against Misinformation with Dr. Sander van der Linden

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