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Comment by Dr. Krishna Kumari Challa on October 23, 2021 at 8:50am

Physicists Created a Supernova Reaction on Earth Using a Radioactive Beam

For the first time, physicists have been able to directly measure one of the ways exploding stars forge the heaviest elements in the Universe.

By probing an accelerated beam of radioactive ions, a team  of physicists observed the proton-capture process thought to occur in core-collapse supernovae.

Not only have scientists now seen how this happens in detail, the measurements are allowing us to better understand the production and abundances of mysterious isotopes called p-nuclei.

On the most basic level, stars can be thought of as the element factories of the Universe. Until stars were born and started smashing together nuclei in their cores, the Universe was a soup of mostly hydrogen and helium. This stellar nuclear fusion started infusing the cosmos with heavier elements, from carbon all the way up to iron for the most massive stars.

This is where core fusion hits a snag. The heat and energy required to produce iron via fusion exceeds the energy the process generates, causing the core temperature to drop, which in turn results in the star dying in a spectacular kaboom – the supernova.

This is where physicists think even heavier elements are born. The explosion is so energetic that atoms, colliding together with force, can capture components from each other. It doesn't have to be a supernova (heavy elements have been detected forming in a collision between two neutron stars) but the principle is the same. Colossal cosmic splodo boom = sufficient energy to forge elements.

Then there are the p-nuclei. These 30 or so naturally occurring isotopes of heavy elements constitute around 1 percent of the heavy elements observed in our Solar System, and their formation is a mystery.

Isotopes are forms of the same element that vary by atomic mass, usually because of a varying number of neutrons in the nucleus, while the number of protons stays the same. P-nuclei are isotopes that are neutron-deficient, but proton-rich; because they are so scarce, they are difficult to observe, which has resulted in some difficulty working out how they are forged.

The currently favored model is the gamma process, in which atoms capture loose protons during an energetic event. Since a chemical element is defined by the number of protons, this process would transform the element into the next one along in the periodic table, resulting in a neutron-poor isotope.

part 1

Comment by Dr. Krishna Kumari Challa on October 23, 2021 at 8:27am

Scientists discover tap water produces a protective shield against microplastics

Tap water produces a natural protective shield against harmful microplastics, which can help prevent household products such as plastic kettles from releasing them. That's according to a team of scientists.
The research, published in the Chemical Engineering Journal, reveals that tap water contains trace elements and minerals, which prevent plastics from degrading in the water and releasing microplastics. Microplastics can carry a range of contaminants such as trace metals and some potentially harmful organic chemicals.
Previous studies investigating microplastics release have used forms of pure water, which only exist in laboratories and do not specifically take into account the ions and impurities found in tap water.
It is well known that plastics can degrade and release microplastics, which can get into the environment and be consumed by humans. This research shows that many items such as plastic kettles, which are repeatedly used with tap water, can develop over time a protective skin that prevents the release of microplastics entirely.
Because tap water is not 100% pure H2O—since it contains trace elements and minerals, what researchers now showed is that if you include these trace elements and minerals the degradation of plastics in tap water is completely different. Rather than the plastics falling apart, the minerals coat the plastic and prevent any kind of degradation and so the product becomes microplastic-free. For example, that dark brown color in your kettle is a good thing. It is copper oxide that forms from copper minerals in your tap water, which in turn comes from the copper pipes in your house—all these combine to give a perfect protection to the kettle.
This discovery is important because we have learned that these types of protective skins can be manufactured in the laboratory and directly applied to the plastic without having to wait for it to build up naturally.

Yunhong Shi et al, Real-world natural passivation phenomena can limit microplastic generation in water, Chemical Engineering Journal (2021). DOI: 10.1016/j.cej.2021.132466

https://phys.org/news/2021-10-scientists-shield-microplastics.html?...

Comment by Dr. Krishna Kumari Challa on October 23, 2021 at 8:18am

Fat cells found to play a central role in cognitive decline and neurodegeneration

Findings published this week reveal new insights into the role of fat cells in cognitive decline and neurodegeneration, according to a study that involves the oxidant amplification loop.

The research, published in iScience, shows that fat cells control the systemic response to brain function, causing impairment in memory and cognition in mice. The activation of Na,K-ATPase oxidant amplification loop affects the expression of important protein markers in fat cells as well as in the hippocampus, which can worsen brain function and lead to neurodegeneration. Targeting the fat cells to antagonize Na,K-ATPase may improve these outcomes. 

 Inducing oxidative stress through western diet increased production of inflammatory cytokines confined to adipocytes as well as altered protein markers of memory and cognition in the hippocampus. 

Western diet induces oxidant stress and adipocyte alteration through Na,K-ATPase signaling which causes systemic inflammation and affects behavioral and brain biochemical changes.

 Komal Sodhi et al, Role of Adipocyte Na,K-ATPase Oxidant Amplification Loop in Cognitive Decline and Neurodegeneration, iScience (2021). DOI: 10.1016/j.isci.2021.103262

https://medicalxpress.com/news/2021-10-fat-cells-central-role-cogni...

Comment by Dr. Krishna Kumari Challa on October 22, 2021 at 12:27pm

Sound Waves Aid Brain Tumor Treatment

In a small clinical study, focusing ultrasound beams on tumors in patients’ brains helped open the blood-brain barrier to facilitate drug delivery.

Afirst-in-human trial reported in Science Translational Medicine today (October 13) demonstrates delivery of an immunotherapy drug to metastatic brain tumors with the help of focused ultrasound. The targeted low-frequency sound waves temporarily opened the normally impenetrable blood-brain barrier at the sites of tumors in stage 4 breast cancer patients, enabling drug entry. Follow up analyses indicated the procedure also led to tumor shrinkage.

It’s a really important step forward in this process of understanding how valuable focused ultrasound will be as a method to deliver drugs to the brain.

https://www.science.org/doi/10.1126/scitranslmed.abj4011?_ga=2.1653...

https://www.the-scientist.com/news-opinion/sound-waves-aid-brain-tu...

Comment by Dr. Krishna Kumari Challa on October 21, 2021 at 10:56am

A breakdown in communication -- mitochondria of diabetic patients can’t keep time

Almost all cells regulate their biological processes over a 24-hour period, otherwise called a cell’s circadian rhythm. To do so, cells use a biological clock that cycles different genes on and off throughout the day and night. Scientists already know that our metabolic health can suffer when our biological clock breaks down, due to shift work or sleep disorders, for example. However, it’s unclear how exactly the biological clock of people with type 2 diabetes differs from healthy people.

Now a team of international scientists has shown that the skeletal muscle in people with type 2 diabetes has a different circadian rhythm. They argue that this might arise because of a communication breakdown between a cell’s time keeping molecules and mitochondria, which produce chemical energy for cells.

In the study, which was published in Science Advances, the scientists first obtained skeletal muscle cells from people with type 2 diabetes and measured which genes showed cycling behavior over two days and compared them with cells from similar healthy people. They discovered that cells from people with type 2 diabetes had fewer, and some different, cycling genes.

They carried out further experiments using data generated from clinical tests in people with type 2 diabetes and mice, as well as cell-based experiments. These experiments demonstrated that mitochondria communicate with the molecules that keep time in our cells, and that this communication is disrupted in people with type 2 diabetes.

Diabetes treatments may be more effective if timed to the body clock

Some of the most widely used pharmacological treatments for type 2 diabetes affect mitochondria, meaning that they may work differently depending on the time of day they are taken. As a result, these findings highlight the importance of considering cellular rhythms when prescribing treatments for type 2 diabetes.

“Exercise and diet are regularly used treatment interventions for people with type 2 diabetes, and both of these treatments can affect the time-keeping molecules and mitochondria.

Given that disrupted sleeping patterns are known to be associated with an increased risk of developing type 2 diabetes, these findings provide evidence of how these disruptions may link to the molecular biology within cells.

https://www.science.org/doi/10.1126/sciadv.abi9654

https://www.eurekalert.org/news-releases/932152

Comment by Dr. Krishna Kumari Challa on October 21, 2021 at 10:29am

Researchers have known how small molecules penetrate cell membranes, typically by binding to the membrane and then diffusing through it. But they knew that proteins do not have that ability because they are too big. Until now, the most popular hypothesis was that proteins pass through small holes, known as pores, in the membrane. But previous work did not support that hypothesis.

While working on other projects, researchers noticed that some fragments of proteins, known as peptides, cross membranes by pushing against them. The peptides deformed the membrane into small circular buds. The buds then detach as small bubbles, known as vesicles, which eventually "pop," allowing the peptides to be released inside the cell. The team subsequently observed that two structurally different bacterial toxins also employed this same mechanism. This discovery led them to conclude that this budding-and-collapse mechanism is a common mechanism employed by many large biomolecules.

The team witnessed the budding-and-collapse in live cells through confocal microscopy, an imaging technique that allowed them to focus in on what was happening inside the cells, and on the cell membranes, with these specific proteins.

Researchers say the discovery could potentially open the door for new drug therapies that use this finding to manipulate the ways drugs enter a cell.

Ashweta Sahni et al, Bacterial Toxins Escape the Endosome by Inducing Vesicle Budding and Collapse, ACS Chemical Biology (2021). DOI: 10.1021/acschembio.1c00540

https://phys.org/news/2021-10-magic-proteins-cell-walls.html?utm_so...

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Comment by Dr. Krishna Kumari Challa on October 21, 2021 at 10:26am

How certain proteins pass through cell walls

All these days scientists have wondered how large molecules such as proteins pass through cell walls, also known as plasma membranes, without leaving a trace. That ability is part of what makes certain drugs—including some cancer treatments and the COVID-19 vaccine—work. And it is also how bacterial toxins enter human cells and wreak havoc.

One such example is diphtheria toxin, which is produced by Corynebacterium diphtheriae and causes diphtheria, a serious and potentially fatal bacterial infection of the nose and throat. But the mechanics of how these proteins enter human cells were a scientific mystery till now.

A recent study, published in the journal ACS Chemical Biology, answers that mystery. The study identified the ways in which proteins cross a cell membrane, a finding that could create a scientific foundation for better ways of delivering drugs into cells in the future, or for treating illnesses caused by bacterial toxins.

It is almost like a magic trick, the way the membrane encapsulates these toxins.

Part 1

Comment by Dr. Krishna Kumari Challa on October 21, 2021 at 9:53am

Researchers make hardened wooden knives that slice through steak

The sharpest knives available are made of either steel or ceramic, both of which are man-made materials that must be forged in furnaces under extreme temperatures. Now, researchers have developed a potentially more sustainable way to make sharp knives: using hardened wood. The method, presented October 20th in the journal Matter, makes wood 23 times harder, and a knife made from the material is nearly three times sharper than a stainless-steel dinner table knife. The knife cuts through a medium-well done steak easily, with similar performance to a dinner table knife.  This hardened wood  knife can be washed and reused, making it a promising alternative to steel, ceramic, and disposable plastic knives.

Teng Li, Hardened Wood as a Renewable Alternative to Steel and Plastic, Matter (2021). DOI: 10.1016/j.matt.2021.09.020. www.cell.com/matter/fulltext/S2590-2385(21)00465-3

https://phys.org/news/2021-10-hardened-wooden-knives-slice-steak.ht...

Comment by Dr. Krishna Kumari Challa on October 20, 2021 at 10:23am

Bacteriophages: an interesting alternative to antibiotics

Bacteriophages are viruses that kill specific types of bacteria.

Phages' ability to selectively kill bacteria also has medical doctors excited. Natural and engineered phages have been successfully used to treat bacterial infections that do not respond to antibiotics. This process, known as phage therapy, could help fight antibiotic resistance.

Comment by Dr. Krishna Kumari Challa on October 20, 2021 at 9:08am

More than 99.9% of studies agree: Humans caused climate change

More than 99.9% of peer-reviewed scientific papers agree that climate change is mainly caused by humans, according to a new survey of 88,125 climate-related studies.

he research updates a similar 2013 paper revealing that 97% of studies published between 1991 and 2012 supported the idea that human activities are altering Earth's climate. The current survey examines the literature published from 2012 to November 2020 to explore whether the consensus has changed.

We now are virtually certain that the consensus is well over 99% now and that it's pretty much case closed for any meaningful public conversation about the reality of human-caused climate change.

It's critical to acknowledge the principal role of greenhouse gas emissions so that we can rapidly mobilize new solutions, since we are already witnessing in real time the devastating impacts of climate related disasters on businesses, people and the economy.

Greater than 99% Consensus on Human Caused Climate Change in the Peer-Reviewed Scientific Literature, Environmental Research Letters (2021). DOI: 10.1088/1748-9326/ac2966, https://iopscience.iop.org/article/10.1088/1748-9326/ac2966

https://phys.org/news/2021-10-humans-climate.html?utm_source=nwlett...

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