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Comment by Dr. Krishna Kumari Challa on August 11, 2023 at 10:30am

Repairing the heart with silicon nanowires and stem cell cardiomyocytes

A research group  has developed a strategy to improve heart repair using human pluripotent stem cell–derived cardiomyocytes combined with biodegradable and biocompatible electroconductive silicon nanowires.

In the paper, "Nanowired human cardiac organoid transplantation enables highly efficient and effective recovery of infarcted hearts," published in Science Advances, the authors detail how cells self-assemble to form organoids that mimic fundamental cardiac tissue–level functions and contain vascular networks that reduce the risk of apoptosis during oxygen deprivation.

Nanowired cardiac organoids, tiny living and contracting orbs of heart tissue with microscopic wires embedded, were fabricated from human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) and cultured along with electroconductive silicon nanowires (e-SiNWs) so that the wires were integrated into the tissues. The engineered spheres were then injected into damaged and dying tissues of rat hearts.

While the use of cardiac organoids for tissue repair is not new, there have been limitations of low cell retention at the repair site, leading to moderate functional improvements and scalability issues.

The addition of nanowires increased the conductivity of the tissues, allowing them to synchronize better, facilitating better communication among cells and integration with the existing heart tissue.

Nanowired organoids achieved double the functional recovery in the rats, with a lower number of engrafted cells (~0.5 × 10⁶ hPSC-CMs per rat) compared to previous studies without nanowires in the hPSC-CMs (~10 × 10⁶ hPSC-CMs per rat).

Integrating e-SiNWs did not exacerbate inflamatory responses in healthy or damage repair settings, as expected from the biocompatible nature of silicon.

Nanowired cardiac organoids also exhibited significantly less apoptosis than wireless cardiac spheroids.

Yu Tan et al, Nanowired human cardiac organoid transplantation enables highly efficient and effective recovery of infarcted hearts, Science Advances (2023). DOI: 10.1126/sciadv.adf2898

Comment by Dr. Krishna Kumari Challa on August 11, 2023 at 10:08am

Researchers engineer bacteria that can detect tumor DNA

Pushing into a new chapter of technologically advanced biological sensors, scientists have engineered bacteria that can detect the presence of tumor DNA in a live organism.

Their innovation, which detected cancer in the colons of mice, could pave the way to new biosensors capable of identifying various infections, cancers and other diseases.

The advancement is described in the journal Science. Bacteria previously have been designed to carry out various diagnostic and therapeutic functions, but lacked the ability to identify specific DNA sequences and mutations outside of cells. The new "Cellular Assay for Targeted CRISPR-discriminated Horizontal gene transfer," or "CATCH," was designed to do just that.

Engineered bacteria detect tumor DNA

The new research is based on previous ideas related to horizontal gene transfer, a technique used by organisms to move genetic material between one another in a manner distinct from traditional parent-to-offspring genetic inheritance. While horizontal gene transfer is widely known from bacteria to bacteria, the researchers achieved their goal of applying this concept from mammalian tumors and human cells into bacteria.

The researchers are now adapting their bacteria biosensor strategy with new circuits and different types of bacteria for detecting and treating human cancers and infections.

 Robert M. Cooper et al, Engineered bacteria detect tumor DNA, Science (2023). DOI: 10.1126/science.adf3974. www.science.org/doi/10.1126/science.adf3974

Comment by Dr. Krishna Kumari Challa on August 10, 2023 at 12:54pm

Physicists demonstrate how sound can be transmitted through vacuum

Did you think that sound waves can't travel through vacuum?

Physicists have demonstrated that in certain situations, sound can be transmitted strongly across a vacuum region!

In a recent article published in Communications Physics they show that in some cases, a sound wave can jump or "tunnel" fully across a vacuum gap between two solids if the materials in question are piezoelectric. In such materials, vibrations (sound waves) produce an electrical response as well, and since an electric field can exist in vacuum, it can transmit the sound waves.

The requirement is that the size of the gap is smaller than the wavelength of the sound wave. This effect works not only in audio range of frequencies (Hz–kHz), but also in ultrasound (MHz) and hypersound (GHz) frequencies, as long as the vacuum gap is made smaller as the frequencies increase.

In most cases the effect is small, but researchers also found situations where the full energy of the wave jumps across the vacuum with 100% efficiency, without any reflections. As such, the phenomenon could find applications in microelectromechanical components (MEMS, smartphone technology) and in the control of heat.

Zhuoran Geng et al, Complete tunneling of acoustic waves between piezoelectric crystals, Communications Physics (2023). DOI: 10.1038/s42005-023-01293-y

Comment by Dr. Krishna Kumari Challa on August 10, 2023 at 12:34pm

Anti-bacterial virus treated antibiotic resistant infections with 86.6% success rate

A new international study conducted by the Israeli Phage Therapy Center (IPTC)  using phage PASA16 on compassionate basis to treat tough Pseudomonas aeruginosa infections, has shown promising results with an 86.6% success rate.

This research involving 16 patients with persistent infections represents the largest of its kind and brings encouraging findings. The study's success demonstrates the potential effectiveness of PASA16 phage therapy in tackling challenging Pseudomonas aeruginosa infections, paving the way for future clinical trials and encouraging further exploration of phage therapy as an alternative and auxiliary approach against antibiotic-resistant infections.

This study sheds light on the potential role of phages in combination with antibiotics in combating the hard-to-treat pathogen P. aeruginosa infections that were unresponsive to conventional treatments.

 Ran Nir-Paz, Refractory Pseudomonas aeruginosa infections treated with Phage PASA16: a compassionate use case series, Med (2023). DOI: 10.1016/j.medj.2023.07.002. www.cell.com/med/fulltext/S2666-6340(23)00225-8

Comment by Dr. Krishna Kumari Challa on August 10, 2023 at 12:20pm

In those spots, and to a lesser extent globally, new studies show a possible warming from the loss of sulfur pollution. And the trend is in places where it really can't be explained as easily by El Niño. There was a cooling effect that was persistent year after year, and suddenly it was removed.

In January 2022, the Hunga Tonga-Hunga Ha'apai undersea volcano in the South Pacific blew, sending more than 165 million tons of water, which is a heat-trapping greenhouse gas as vapour. The volcano also blasted 550,000 tons (500,000 metric tons) of sulfur dioxide into the upper atmosphere. A couple of studies use computer models to show a warming effect from all that water vapour.

However, the studies that showed warming from Hunga Tonga didn't incorporate sulfur cooling, which is hard to do.

Scientists 're still just trying to figuring it out.

Lesser suspects in the search include a dearth of African dust, which cools like sulfur pollution, as well as changes in the jet stream and a slowdown in ocean currents.

Some nonscientists have looked at recent solar storms and increased sunspot activity in the sun's 11-year cycle and speculated that Earth's nearest star may be a culprit. However, for decades, scientists have tracked sunspots and solar storms, and they don't match warming temperatures.

Solar storms were stronger 20 and 30 years ago, but there is more warming now.

 Still, other scientists said there's no need to look so hard. They say human-caused climate change, with an extra boost from El Niño, is enough to explain recent temperatures. The fact that the world is coming out of a three-year La Niña, which suppressed global temperatures a bit, and going into a strong El Niño, which adds to them, makes the effect bigger.

Climate change and El Niño can explain it all. That doesn't mean other factors didn't play a role. But we should definitely expect to see this again without the other factors being present.

Source: The Associate Press

Part 2

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Comment by Dr. Krishna Kumari Challa on August 10, 2023 at 12:12pm

Scientists look beyond climate change and El Nino for other factors that heat up Earth

Scientists are trying to find out if global warming and El Niño have an accomplice in fueling this summer's record-shattering heat.

The European climate agency Copernicus reported that July was one-third of a degree Celsius (six-tenths of a degree Fahrenheit) hotter than the old record. That's a bump in heat that is so recent and so big, especially in the oceans and even more so in the North Atlantic, that scientists are split on whether something else could be at work.

Scientists agree that by far the biggest cause of the recent extreme warming is climate change from the burning of coal, oil and natural gas that has triggered a long upward trend in temperatures. A natural El Niño, a temporary warming of parts of the Pacific that changes weather worldwide, adds a smaller boost. But some researchers say another factor must be present.

One surprising source of added warmth could be cleaner air resulting from new shipping rules. Another possible cause is 165 million tons (150 million metric tons) of water spewed into the atmosphere by a volcano. Both ideas are under investigation.

Shipping is "probably the prime suspect". Maritime shipping has for decades used dirty fuel that gives off particles that reflect sunlight in a process that actually cools the climate and masks some of global warming.

In 2020, international shipping rules took effect that cut as much as 80% of those cooling particles, which was a "kind of shock to the system". The sulfur pollution used to interact with low clouds, making them brighter and more reflective, but that's not happening as much now.

Part 1

Comment by Dr. Krishna Kumari Challa on August 10, 2023 at 11:59am

World's largest study shows the more you walk, the lower your risk of death, even if you walk fewer than 5,000 steps

The number of steps you should walk every day to start seeing benefits to your health is lower than previously thought, according to the largest analysis to investigate this.

The study, published in the European Journal of Preventive Cardiology recently, found that walking at least 3967 steps a day started to reduce the risk of dying from any cause, and 2337 steps a day reduced the risk of dying from diseases of the heart and blood vessels (cardiovascular disease). However, the new analysis of 226,889 people from 17 different studies around the world has shown that the more you walk, the greater the health benefits. The risk of dying from any cause or from cardiovascular disease decreases significantly with every 500 to 1000 extra steps you walk. An increase of 1000 steps a day was associated with a 15% reduction in the risk of dying from any cause, and an increase of 500 steps a day was associated with a 7% reduction in dying from cardiovascular disease.

They found that even if people walked as many as 20,000 steps a day, the health benefits continued to increase. They have not found an upper limit yet.

This study confirms that the more you walk, the better. They found that this applied to both men and women, irrespective of age, and irrespective of whether you live in a temperate, sub-tropical or sub-polar region of the world, or a region with a mixture of climates. In addition, this analysis indicates that as little as 4,000 steps a day are needed to significantly reduce deaths from any cause, and even fewer to reduce deaths from cardiovascular disease.

There is strong evidence that a sedentary lifestyle may contribute to an increase in cardiovascular disease and a shorter life. Studies have shown that insufficient physical activity affects more than a quarter of the world's population.

According to World Health Organization data, insufficient physical activity is the fourth most frequent cause of death in the world, with 3.2 million deaths a year related to physical inactivity.

Maciej Banach et al, The Association Between Daily Step Count and All-Cause and Cardiovascular Mortality: A Meta-Analysis, European Journal of Preventive Cardiology (2023). DOI: 10.1093/eurjpc/zwad229

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Comment by Dr. Krishna Kumari Challa on August 9, 2023 at 11:29am

Microwaving 'Safe' Plastics Can Release Billions of Particles, Scientists Warn

Billions of nanometer-wide particles can be released from plastic containers into the food they're holding when they're microwaved, a new study reveals. A team from the University of Nebraska-Lincoln in the US ran experiments using baby food containers made from polypropylene and polyethylene, which are both approved as safe to use by the regulators at the US Food and Drug Administration (FDA).

After three minutes of being heated in a 1,000-watt microwave, a variety of liquids put inside the containers were analyzed for microplastics (at least 1/1,000th of a millimeter in diameter) and nanoplastics (even smaller).

Particle numbers varied, but the researchers estimated that 4.22 million microplastic and 2.11 billion nanoplastic particles from only one square centimeter of plastic could be released during those three minutes of microwave heating.

Microwaving water or dairy products inside polypropylene or polyethylene products is likely to deliver the highest relative concentrations of plastic, the researchers revealed. Particles were also released when food and drinks were refrigerated and stored at room temperature, but significantly fewer in number.

What's not clear right now is what these microscopic plastic particles are doing to us. Studies have shown they can potentially be harmful to the intestine and key biological processes, but it's an area scientists aren't sure about.

It's probably safe to say that the less plastic we're ingesting the better, though. Embryonic kidney cells cultured by the researchers and exposed to plastic particles at levels of concentrations released by the containers over several days revealed a potential for concern.

The team found 77 percent of the kidney cells exposed to the highest levels of plastic were killed off. While this isn't to say our own kidneys would necessarily be exposed directly to such concentrations, it gives us some idea of the potential toxicity of these microplastics and nanoplastics – particular in developing bodies.

https://pubs.acs.org/doi/10.1021/acs.est.3c01942

Comment by Dr. Krishna Kumari Challa on August 9, 2023 at 10:34am

Asteroid Mining & Orbital Settlements

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Comment by Dr. Krishna Kumari Challa on August 9, 2023 at 9:57am

In mice, just three days of a fat-rich diet is enough to cause this inflammation. Other studies have shown that this inflammation can raise the threshold at which animals are full—in other words, they have to eat more food than usual to feel full.

Inflammation may explain why the hypothalamus is larger in these individuals, the team say. One suggestion is that the body reacts to inflammation by increasing the size of the brain's specialist immune cells, known as glia.

The team say more research is needed to confirm whether increased volume in the hypothalamus is a result of being overweight or whether people with larger hypothalami are predisposed to eat more in the first place. It is also possible that these two factors interact with each other causing a feedback loop.

Stephanie S.G. Brown Conceptualisation et al, Hypothalamic volume is associated with body mass index, NeuroImage: Clinical (2023). DOI: 10.1016/j.nicl.2023.103478

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