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Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 12:31pm

Deforestation in the Amazon may be decreasing the frequency of thun...

For the first time, researchers from Tel Aviv University have determined that due to the ongoing deforestation in the Amazon basin in recent decades, the number of thunderstorms in the region has decreased significantly, and the area over which they occur has shrunk.

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Shape matters: Study finds microplastic fibers may travel as far as...

How far microplastics travel in the atmosphere depends crucially on particle shape, according to a recent study by scientists at the University of Vienna and the Max Planck Institute for Dynamics and Self-Organization in Göttingen. Although spherical particles settle quickly, microplastic fibers might travel as far as the stratosphere.

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The first breath of green

The oldest fossil evidence of photosynthesis has been found inside tiny cyanobacteria that lived around 1.75 billion years ago, 1.2 billion years earlier than the previous record-holder. The photosynthetic structures, known as thylakoids, were found inside fossilized Navifusa majensis. Cyanobacteria are thought to have triggered the Great Oxidation Event more than 2 billion years ago, which transformed Earth’s atmosphere. “One idea is that, perhaps, they invented thylakoids at this time and this increased the quantity of oxygen on Earth,” says paleobiologist Emmanuelle Javaux, who contributed to the discovery. “Now that we’ve found very old thylakoids and that they can be preserved in very old rocks, we think that we could go further back in time and try to test this hypothesis.”

https://www.nature.com/articles/s41586-023-06896-7.epdf?sharing_tok...

New Scientist

Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 10:47am

Nanomachines: what are they?
Professor Ben Feringa at the University of Groningen in the Netherlands won the Nobel Prize in Chemistry in 2016 for nanomachines with molecular motors that could be turned on by ultraviolet light.

The molecules change shape when struck by light and, as a result, can be used as switches or triggers.
Some of these nanomachines have the potential to treat cancer patients in ways that excite scientists and doctors. Today's cancer drugs often inflict side effects such as loss of hair, nausea, fatigue or immune-system weakness. This is because the drugs can maim healthy bystander cells.
A future scenario could involve nanomachines delivering cell-killing drugs precisely to a patient's cancer, perhaps burrowing inside any tumor. So some researchers are constructing materials that can be used to ferry vaccines or nanomedicines inside cells, including cancers.
Some are creating polymer nanoparticles to deliver future gene therapies to precise locations inside patients. The particles are often coated sugars because they are able to act as a key to open cells in the body. These synthetic sugars can interact with cell membranes and can give the particle a key to open the door and get a gene inside the cell.
Others are working on lipid nanoparticles, which are tiny spheres made of fats that can safely get inside cells. Lipid nanoparticles were the real breakthrough needed for COVID-19 vaccines.
The next big change for the pharma industry will be to train our genes to prevent cancer or to fight against cancer.

Source: 

• REBELLION
• BIOMOLMACS

Part 3

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Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 10:41am

Their two parts are smaller than 100 nanometers, so 1,000th the width of a human hair—effectively making them minnows alongside larger bacteria.

Researchers released many millions of nanomachines in clumps of bacteria in the laboratory. The machines bound to the bacteria and, once exposed to light, began spinning and drilling into them.

The scene under the microscope: bacteria cells riddled with tiny holes. Further experiments showed that the tiny drills can kill an array of strains that commonly infect people.Having a lower concentration of machines would lessen the risk of damage to human cells.

The instruments punctured the MRSA with enough holes so that it was once again vulnerable to antibiotics.

It is very hard for bacteria to develop resistance against this action.

To deploy this new weapon against resistant bacteria, the researchers will need to ensure that the nanomachines are safe to use on patients. That means being sure that bacteria rather than human cells get targeted.

One early reason for optimism is that the nanomachines are positively charged. As a result, they prefer to attach themselves to negatively charged bacteria rather than to human cells, which are more neutral.
In the experiments by researchers, the nanomachines caused no harm to worms when injected into them.
next step: safety tests in mice.

If successful, the first patients treated might be ones with wound infections—especially people with severe burns, which are prone to infection.

The nanomachines could be placed on their skin and switched on by light to drill into bacteria that are infecting the wound.
Part 2

Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 10:31am

Fighting superbugs with medical nanomachines

Instruments smaller than a human hair are being designed to eradicate antibiotic-resistant bacteria and fight cancer.

Because even in an age of antibiotics, people are dying of infections. 'Are we going back in time?' is the question experts are posing as our antibiotics are no longer effective. This is a global challenge. Almost 5 million deaths worldwide were linked to antibiotic-resistant bugs in 2019, according to The Lancet medical journal.

Six types of resistant bacteria inflict the most harm. The World Health Organization has warned that drug-resistant diseases could directly cause 10 million deaths by 2050.

In an arms race, microorganisms evolved various defenses to survive antibiotics.

Antibiotics often latch onto a specific bacterial protein, much like a key fits into a lock. The trouble is that bacteria can undergo a physical change so that the key no longer fits the lock. The antibiotics are left outside.

So the idea behind the nanomachines is that they would be tougher for bacteria to evade as these are bug-killing machines.

Part 1

Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 9:34am

In fruit bats, the compositions of the pancreas and kidneys evolved to accommodate their diet. The pancreas had more cells to produce insulin, which tells the body to lower blood sugar, as well as more cells to produce glucagon, the other major sugar-regulating hormone. The fruit bat kidneys, meanwhile, had more cells to trap scarce salts as they filtered blood.

Zooming in, the regulatory DNA in those cells had evolved to turn the appropriate genes for fruit metabolism on or off. The big brown bat, on the other hand, had more cells for breaking down protein and conserving water. The gene expression in those cells was tuned to handle a diet of bugs.

The organization of the DNA around the insulin and glucagon genes was very clearly different between the two bat species. The DNA around genes used to be considered 'junk,' but new data shows that this regulatory DNA likely helps fruit bats react to sudden increases or decreases in blood sugar.

While some of the biology of the fruit bat resembled what's found in humans with diabetes, the fruit bat appeared to evolve something that humans with a sweet tooth could only dream of: a sweet tooth without consequences. Bats biology has figured it out, and it's all in their DNA, the result of natural selection!

The study benefited from a recent ground swell of interest in studying bats to better human health.  One of the Jamaican fruit bats was used in the sugar metabolism study.

As one of the most diverse families of mammals, bats include many examples of evolutionary triumph, from their immune systems to their peculiar diets and beyond.

Bats are like superheroes, each one with an amazing super power, whether it is echolocation, flying, blood sucking without coagulation, or eating fruit and not getting diabetes.

Scientists are trying to learn all these tricks from bats.

Wei Gordon et al, Nature Communications (2024). www.nature.com/articles/s41467-023-44186-y

Part 2

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Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 9:29am

How fruit bats evolved to consume so much sugar may have implications for diabetes research

A high-sugar diet is bad news for humans, leading to diabetes, obesity and even cancer. Yet fruit bats survive and even thrive by eating up to twice their body weight in sugary fruit every day.

Now scientists have discovered how fruit bats may have evolved to consume so much sugar, with potential implications for the millions of people with diabetes. The findings, published in Nature Communications, point to adaptations in the fruit bat body that prevent their sugar-rich diet from becoming harmful.

 Fruit bats have a genetic system that controls blood sugar without fail. Scientists are learning from that system to make better insulin- or sugar-sensing therapies for people.

They found that the fruit bat pancreas, compared to the pancreas of an insect-eating bat, had extra insulin-producing cells as well as genetic changes to help it process an immense amount of sugar. Additionally, fruit bat kidneys had adapted to ensure that vital electrolytes would be retained from their watery meals.

Even small changes, to single letters of DNA, make this diet viable for fruit bats. We need to understand high-sugar metabolism like this to make progress helping the people who are prediabetic.

Part 1

Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 9:21am

Researchers engineer skin bacteria that are able to secrete and produce molecules that treat acne

International research has succeeded in efficiently engineering Cutibacterium acnes, a type of skin bacterium, to produce and secrete a therapeutic molecule suitable for treating acne symptoms.

The engineered bacterium has been validated in skin cell lines and its delivery has been validated in mice. This finding opens the door to broadening the way for engineering non-tractable bacteria to address skin alterations and other diseases using living therapeutics.

The results of the study, published in Nature Biotechnology, show that researchers have successfully edited the genome of Cutibacterium acnes to secrete and produce NGAL protein known to be a mediator of the acne drug isotretinoin, which has been shown to reduce sebum by inducing the death of sebocytes.

Delivery of a sebum modulator by an engineered skin microbe in mice, Nature Biotechnology (2024). DOI: 10.1038/s41587-023-02072-4

Comment by Dr. Krishna Kumari Challa on January 10, 2024 at 9:03am

Different biological variants discovered in Alzheimer's disease

Scientists recently have discovered five biological variants of Alzheimer's disease, which may require different treatments. As a result, previously tested drugs may incorrectly appear to be ineffective or only minimally effective.

In those with Alzheimer's disease, the amyloid and tau proteins clump in the brain. In addition to these clumps, other biological processes such as inflammation and nerve cell growth are also involved. Using new techniques, the researchers have been able to measure these other processes in the cerebrospinal fluid of patients with amyloid and tau clumps.

Researchers examined 1,058 proteins in the cerebrospinal fluid of 419 people with Alzheimer's disease. They found that there are five biological variants within this group. The first variant is characterized by increased amyloid production. In a second type, the blood-brain barrier is disrupted, and there is reduced amyloid production and less nerve cell growth.
Furthermore, the variants differ in the degree of protein synthesis, the functioning of the immune system, and the functioning of the organ that produces cerebrospinal fluid. Patients with different Alzheimer's variants also showed differences in other aspects of the disease. For example, the researchers found a faster course of the disease in certain subgroups.

The findings are of great importance for drug research. They could mean that a certain drug might only work in one variant of Alzheimer's disease. For example, medication that inhibits amyloid production may work in the variant with increased amyloid production, but may be harmful in the variant with decreased amyloid production. It is also possible that patients with one variant would have a higher risk of side effects, while that risk would be much lower with other variants.

The next step for the research team is to show that the Alzheimer's variants do indeed react differently to medicines, in order to treat all patients with appropriate medicines in the future.

Cerebrospinal fluid proteomics in Alzheimer's disease patients reveals five molecular subtypes with distinct genetic risk profiles, Nature Aging (2024).

Comment by Dr. Krishna Kumari Challa on January 9, 2024 at 9:21am

One common one was polyethylene terephthalate or PET. This was not surprising, since that is what many water bottles are made of. (It is also used for bottled sodas, sports drinks and products such as ketchup and mayonnaise.) It probably gets into the water as bits slough off when the bottle is squeezed or gets exposed to heat. One recent study suggests that many particles enter the water when you repeatedly open or close the cap, and tiny bits abrade.
However, PET was outnumbered by polyamide, a type of nylon that probably comes from plastic filters used to supposedly purify the water before it is bottled. Other common plastics the researchers found: polystyrene, polyvinyl chloride and polymethyl methacrylate, all used in various industrial processes.
A somewhat disturbing thought: the seven plastic types the researchers searched for accounted for only about 10% of all the nanoparticles they found in samples; they have no idea what the rest are. If they are all nanoplastics, that means they could number in the tens of millions per liter.

But they could be almost anything, "indicating the complicated particle composition inside the seemingly simple water sample," the authors write. "The common existence of natural organic matter certainly requires prudent distinguishment."

Rapid single-particle chemical imaging of nanoplastics by SRS microscopy, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2300582121. doi.org/10.1073/pnas.2300582121

Part 2

Comment by Dr. Krishna Kumari Challa on January 9, 2024 at 9:19am

Bottled water can contain hundreds of thousands of previously uncounted tiny plastic bits, study finds

In recent years, there has been rising concern that tiny particles known as microplastics are showing up basically everywhere on Earth, from polar ice to soil, drinking water and food. Formed when plastics break down into progressively smaller bits, these particles are being consumed by humans and other creatures, with unknown potential health and ecosystem effects.

One big focus of research: bottled water, which has been shown to contain tens of thousands of identifiable fragments in each container.

Now, using newly-refined technology, researchers have entered a whole new plastic world: the poorly known realm of nanoplastics, the spawn of microplastics that have broken down even further.

For the first time, they counted and identified these minute particles in bottled water. They found that on average, a liter contained some 240,000 detectable plastic fragments—10 to 100 times greater than previous estimates, which were based mainly on larger sizes.

The study was published in the journal Proceedings of the National Academy of Sciences.

Nanoplastics are so tiny that, unlike microplastics, they can pass through intestines and lungs directly into the bloodstream and travel from there to organs including the heart and brain. They can invade individual cells, and cross through the placenta to the bodies of unborn babies. Medical scientists are racing to study the possible effects on a wide variety of biological systems.

Unlike natural organic matter, most plastics do not break down into relatively benign substances; they simply divide and redivide into smaller and smaller particles of the same chemical composition. Beyond single molecules, there is no theoretical limit to how small they can get.

Microplastics are defined as fragments ranging from 5 millimeters (less than a quarter inch) down to 1 micrometer, which is 1 millionth of a meter, or 1/25,000th of an inch. (A human hair is about 70 micrometers across.) Nanoplastics, which are particles below 1 micrometer, are measured in billionths of a meter.

Plastics in bottled water became a public issue largely after a 2018 study detected an average of 325 particles per liter; later studies multiplied that number many times over. Scientists suspected there were even more than they had yet counted, but good estimates stopped at sizes below 1 micrometer—the boundary of the nano world.

The new study uses a technique called stimulated Raman scattering microscopy .This involves probing samples with two simultaneous lasers that are tuned to make specific molecules resonate. Targeting seven common plastics, the researchers created a data-driven algorithm to interpret the results. It is one thing to detect, but another to know what you are detecting .

The researchers tested three popular brands of bottled water sold in the United States (they declined to name which ones), analyzing plastic particles down to just 100 nanometers in size.
They spotted 110,000 to 370,000 particles in each liter, 90% of which were nanoplastics; the rest were microplastics. They also determined which of the seven specific plastics they were, and charted their shapes—qualities that could be valuable in biomedical research.

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