Comment

Comment by Dr. Krishna Kumari Challa on September 25, 2021 at 8:25am

Reprogramming heart muscle cells to repair damage from heart attacks

A team of researchers has found that it is possible to reprogram heart muscle to repair damaged tissue. In their paper published in the journal Science, the group describes their approach to repairing damaged hearts in mice and how well it worked when tested.

There are two main kinds of heart attack. The first occurs when something prevents the heart from beating. The second occurs when blood flow is restricted to parts of the heart, preventing the muscle in that area from beating. The first kind is generally fatal unless the heart can be restarted very quickly. The second is generally less serious, but can leave permanent, debilitating scarring. In this new effort, the researchers have found a way to prevent such scarring—at least in mice.

The work built on prior research that showed that in the case of a baby experiencing heart damage in utero, the heart can repair itself because the cardiomyocyte cells are in a state that allows rejuvenation. This is not the case after birth or later in life, as the cardiomyocytes have no ability to regenerate. After several years of effort, the researchers discovered a way to get adult cardiomyocytes to revert back to fetal-like cardiomyocytes by reprogramming them using the Yamanaka factors c-Myc, Klf4, Sox2 and Oct4. Their research showed that such factors express for cell renewal. The reprogramming also featured an on/off switch using the antibiotic doxycycline. 

The researchers then tested their approach by giving mice with reprogrammed cells doxycycline just prior to and after inducing heart damage. They found that under both scenarios, heart regeneration occurred along with heart function improvement. The researchers also tried giving similar test mice doxycycline six days after experiencing heart damage and found it had no impact. Thus, the window of repair is short. Further testing also showed that if doxycycline was administered for too long a period, cancerous tumors developed. Much more work is required to determine if a similar approach might work for humans, and if it can be done without increasing the risk of cancer.

Yanpu Chen et al, Reversible reprogramming of cardiomyocytes to a fetal state drives heart regeneration in mice, Science (2021). DOI: 10.1126/science.abg5159

https://medicalxpress.com/news/2021-09-reprogramming-heart-muscle-c...

Comment by Dr. Krishna Kumari Challa on September 24, 2021 at 12:14pm

Winged microchip is smallest-ever human-made flying structure

Inspired by the way trees like maples disperse their seeds using little more than a stiff breeze, researchers developed a range of tiny flying microchips, the smallest one hardly bigger than a grain of sand.

This flying microchip or 'microflier' catches wind and spins like a helicopter towards the ground.

The microfliers can be packed with ultra-miniaturized technology, including sensors, power sources, antennas for wireless communication, and even embedded memory for data storage.

Comment by Dr. Krishna Kumari Challa on September 24, 2021 at 10:07am

The Roman Space Telescope's Wide Field Instrument

Comment by Dr. Krishna Kumari Challa on September 24, 2021 at 9:36am

Hairdressers say people are having allergic reactions to hair dye due to COVID

Covid-19: New allergic reactions to hair dye reported

It's important to always get a patch test before using a beauty product

News that there is a link between COVID-19 and allergies to hair dye is being reported more and more. Over the past year, more and more hairdressers have noticed a worrying increase in customers suffering allergic reactions to hair dye after testing positive for COVID-19.

Hairdressers report customers developing rashes and burns after using hair dye, even if it's a product they've used before. Now, according to the BBC, the trade body that represents hairdressers and beauticians is warning professionals to carry out additional patch tests to avoid facing legal action. Patch tests require customers to sample the product on their skin 24-48 hours before their appointment to see how they react.

https://www.bbc.com/news/av/health-58651244

https://www.cosmopolitan.com/uk/body/health/a37703414/allergic-reac...

Comment by Dr. Krishna Kumari Challa on September 23, 2021 at 9:57am

Flying cars

Comment by Dr. Krishna Kumari Challa on September 23, 2021 at 9:51am

Global cancer risk from burning organic matter comes from unregulated chemicals

Whenever organic matter is burned, such as in a wildfire, a power plant, a car's exhaust, or in daily cooking, the combustion releases polycyclic aromatic hydrocarbons (PAHs)—a class of pollutants that is known to cause lung cancer.

There are more than 100 known types of PAH compounds emitted daily into the atmosphere. Regulators, however, have historically relied on measurements of a single compound, benzo(a)pyrene, to gauge a community's risk of developing cancer from PAH exposure. Now MIT scientists have found that benzo(a)pyrene may be a poor indicator of this type of cancer risk.

In a modeling study appearing today in the journal GeoHealth, the team reports that benzo(a)pyrene plays a small part—about 11 percent—in the global risk of developing PAH-associated cancer. Instead, 89 percent of that cancer risk comes from other PAH compounds, many of which are not directly regulated.

Interestingly, about 17 percent of PAH-associated cancer risk comes from "degradation products"—chemicals that are formed when emitted PAHs react in the atmosphere. Many of these degradation products can in fact be more toxic than the emitted PAH from which they formed.

Jamie M. Kelly et al, Global Cancer Risk from Unregulated Polycyclic Aromatic Hydrocarbons, GeoHealth (2021). DOI: 10.1029/2021GH000401

https://phys.org/news/2021-09-global-cancer-unregulated-chemicals.h...

**

Comment by Dr. Krishna Kumari Challa on September 23, 2021 at 9:44am

Infants have more microplastics in their feces than adults, study finds

Microplastics—tiny plastic pieces less than 5 mm in size—are everywhere, from indoor dust to food to bottled water. So it's not surprising that scientists have detected these particles in the feces of people and pets. Now, in a small pilot study, researchers reporting in ACS' Environmental Science & Technology Letters discovered that infants have higher amounts of one type of microplastic in their stool than adults. Health effects, if any, are uncertain.

Little is known about the magnitude of human exposure to microplastics or their health effects. Although microplastics were once thought to pass harmlessly through the gastrointestinal tract and exit the body, recent studies suggest that the tiniest pieces can cross cell membranes and enter the circulation. In cells and laboratory animals, microplastic exposure can cause cell death, inflammation and metabolic disorders.

The researchers used mass spectrometry to determine the concentrations of PET and PC microplastics in six infant and 10 adult feces samples collected from New York state, as well as in three samples of meconium (a newborn infant's first stool). All samples contained at least one type of microplastic. Although average levels of fecal PC microplastics were similar between adults and infants, infant stool contained, on average, more than 10 times higher PET concentrations than that of adults.

Infants could be exposed to higher levels of microplastics through their extensive use of products such as bottles, teethers and toys, the researchers say.

Occurrence of Polyethylene Terephthalate and Polycarbonate Microplastics in Infant and Adult Feces, Environmental Science & Technology Letters (2021). pubs.acs.org/doi/abs/10.1021/acs.estlett.1c00559

https://phys.org/news/2021-09-infants-microplastics-feces-adults.ht...

Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 1:26pm

Brain-Eating Amoeba

Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 1:20pm

Salty Diet Helps Gut Bugs Fight Cancer in Mice: Study

A high-salt diet suppressed the growth of tumors in a mouse model of melanoma, apparently because of an interplay between the gut microbiome and natural killer cells.

Salt may not be good for your BP, but .....

In mice, a diet high in salt suppresses tumor growth—but only when gut microbes are there to stimulate immune cells, a September 10 study in Science Advances reports. The findings raise tantalizing questions about the role of diet and gut microbes in human cancers, and may point to new avenues for therapeutic development.

While the study isn’t the first to connect a high-salt diet to shrinking tumors, the authors have shown a unique mechanistic role of high salt induced gut microbiome changes as the central phenomenon behind their observed anti-cancer effect.

The researchers  pursued this line of inquiry because previous research had linked high salt intake with autoimmune diseases, suggesting that increased salt stimulates immune cells. Meanwhile, tumors are well known to grow in immune-suppressive environments. So they thought, “If we put salt in the mice’s diet, maybe [the immune system in] the tumor environment becomes activated,” suppressing cancerous growth.

a 2019 Frontiers in Immunology study from a European team led by Hasselt University immunologist Markus Kleinewietfeld reported that high-salt diets inhibited tumor growth in mice. No researchers carried out similar experiments, implanting mice with B16F10 skin melanoma cells and then feeding the tumor transplant mice diets with different salt levels, they got similar results: tumors grew slower in mice who were fed a high-salt diet.

https://www.science.org/doi/10.1126/sciadv.abg5016

https://www.the-scientist.com/news-opinion/a-salty-diet-helps-gut-b...

Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 12:57pm

the researchers computed how many satellites will be in the sky at different times of year, at different hours of the night and from different positions on Earth’s surface. They also estimated how bright the satellites were likely to be at different hours of the day and times of the year.

The simulations showed that “the way the night sky is going to change will not affect all places equally,” Lawler says. The places where naked-eye stargazing will be most affected are at latitudes 50° N and 50° S, regions that cross lower Canada, much of Europe, Kazakhstan and Mongolia, and the southern tips of Chile and Argentina, the researchers found.

The geometry of sunlight in the summer means there will be hundreds of visible satellites all night long. It’s bad everywhere, but it’s worse there.

--

A few visible satellites can be a fun spectacle. Astronomers have been meeting with representatives from private companies, as well as space lawyers and government officials, to work out compromises and mitigation strategies. Companies have been testing ways to reduce reflectivity, like shading the satellites with a “visor.” Other proposed strategies include limiting the satellites to lower orbits, where they move faster across the sky and leave a fainter streak in telescope images. Counterintuitively, lower satellites may be better for some astronomy research. “They move out of the way quick.”

But that lower altitude strategy will mean more visible satellites for other parts of the world, and more that are visible to the naked eye.

There are some latitudes on Earth where no matter what altitude you put your satellites at, they’re going to be all over the darn place. The only way out of this is fewer satellites.

There are currently no regulations concerning how bright a satellite can be or how many satellites a private company can launch. Scientists are grateful that companies are willing to work with them, but think that their cooperation is voluntary. Efforts are under way to bring the issue to the attention of the United Nations and to try to use existing environmental regulations to place limits on satellite launches.

S. Lawler, A. Boley and H. Rein. Visibility predictions for near-future satellite megaconstellations.... arXiv:2109.04328. Posted September 9, 2021.

https://www.sciencenews.org/article/satellite-mega-constellations-n...

• ‹ Previous
• 1
• …
• 552
• 553
• 554
• 555
• 556
• …
• 1063
• Next ›
• Page