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Comment by Dr. Krishna Kumari Challa on April 21, 2022 at 6:20am

During the experiment, scientists were surprised to also detect titanium dioxide in the "control" group of rats that hadn't been given nanoparticles to inhale. It turns out the food given to the animals contained titanium dioxide. As a result, the researchers were able to observe the path the metal took through a rat's body.

The research emerged from investigations into the causes of low birth weight in human infants. Newborns weighing less than 5.5 pounds can suffer adverse health effects as infants and throughout their lives.

According to Stapleton, one theory is mothers who give birth to babies with low birth weights may have inhaled harmful particulates. The resulting inflammation may affect bodily systems, such as blood flow in the uterus, that could inhibit growth of the fetus.

J.N. D'Errico et al, Maternal, placental, and fetal distribution of titanium after repeated titanium dioxide nanoparticle inhalation through pregnancy, Placenta (2022). DOI: 10.1016/j.placenta.2022.03.008

https://medicalxpress.com/news/2022-04-nanoparticles-placenta-pregn...

Part 2

Comment by Dr. Krishna Kumari Challa on April 21, 2022 at 6:19am

Nanoparticles can cross the placenta during pregnancy, potentially exposing fetus

Most nanoparticles are engineered, with few produced naturally. These particles are used in thousands of products, from sunscreens to pharmaceuticals to sports equipment. They are highly valued because they can enhance the effectiveness of drugs and produce sturdy-though-lightweight products.

Nanoparticles are so named because they are less than 100 nanometers wide, meaning they are tens of thousands of times smaller than the diameter of a single human hair. Despite their usefulness, nanoscale materials are poorly understood, with very little known about the potential effects on human health and the environment.

Inhaled nanoparticles—human-made specks so minuscule they can't be seen in conventional microscopes, found in thousands of common products—can cross a natural, protective barrier that normally protects fetuses, according to  scientists studying factors that produce low-birth-weight babies.

The scientists reported in the medical journal Placenta they were able to track the movement of nanoparticles made of metal titanium dioxide through the bodies of pregnant rats. After the nanoparticles were inhaled into the lungs of the rodents, some of them escaped this initial barrier. From there, the particles flowed through the placentas, which generally filter out foreign substances to protect the fetus.

Using some specialized techniques, researchers found evidence that the particles can migrate from the lung to the placenta and possibly the fetal tissues after maternal exposure throughout pregnancy. The placenta does not act as a barrier to these particles. Nor do the lungs.

Part 1

Comment by Dr. Krishna Kumari Challa on April 21, 2022 at 6:13am

Astronomers discover micronovae, a new kind of stellar explosion

A team of astronomers, with the help of the European Southern Observatory's Very Large Telescope (ESO's VLT), have observed a new type of stellar explosion—a micronova. These outbursts happen on the surface of certain stars, and can each burn through around 3.5 billion Great Pyramids of Giza of stellar material in only a few hours.

The phenomenon challenges our understanding of how thermonuclear explosions in stars occur. We thought we knew this, but this discovery proposes a totally new way to achieve them.

Micronovae are extremely powerful events, but are small on astronomical scales; they are much less energetic than the stellar explosions known as novae, which astronomers have known about for centuries. Both types of explosions occur on white dwarfs, dead stars with a mass about that of our sun, but as small as Earth.

A white dwarf in a two-star system can steal material, mostly hydrogen, from its companion star if they are close enough together. As this gas falls onto the very hot surface of the white dwarf star, it triggers the hydrogen atoms to fuse into helium explosively. In novae, these thermonuclear explosions occur over the entire stellar surface. Such detonations make the entire surface of the white dwarf burn and shine brightly for several weeks.

Micronovae are similar explosions that are smaller in scale and faster, lasting just several hours. They occur on some white dwarfs with strong magnetic fields, which funnel material towards the star's magnetic poles. For the first time, researchers have now seen that hydrogen fusion can also happen in a localized way. The hydrogen fuel can be contained at the base of the magnetic poles of some white dwarfs, so that fusion only happens at these magnetic poles.

This leads to micro-fusion bombs going off, which have about one millionth of the strength of a nova explosion, hence the name micronova.

 Simone Scaringi et al, Localized thermonuclear bursts from accreting magnetic white dwarfs, Nature (2022). DOI: 10.1038/s41586-022-04495-6. www.nature.com/articles/s41586-022-04495-6

https://phys.org/news/2022-04-astronomers-micronovae-kind-stellar-e...

Comment by Dr. Krishna Kumari Challa on April 21, 2022 at 5:25am

There's Something Different About Clouds in Antarctica

Clouds that form in the frosty air above Antarctica are different in the way that water and ice interact inside them, a new study reveals – and that in turn changes how much sunlight they reflect back into space, which is important for climate change models.

Through a combination of modeling, satellite imagery and data collected from flying through the clouds themselves, researchers have identified a process of 'secondary' ice production. This means icy particles collide with supercooled water droplets, freezing and then shattering them, creating many more shards of ice.

The technical term for this sequence of events is Hallett-Mossop rime splintering. It dims the clouds, reducing the amount of sunlight that's reflected back into space, and allowing more of it through into the ocean below. "The Southern Ocean is a massive global heat sink, but its ability to take heat from the atmosphere depends on the temperature structure of the upper ocean, which relates to the cloud cover.

Based on the researchers' calculations, in clouds at temperatures between -3°C and -8°C (26.6°F and 17.6°F), around 10 Watts per square meter of extra energy could reach the ocean from the Sun, enough to significantly change temperatures.

Ice formation inside these clouds is very efficient, and the resulting ice can fall down into the ocean very quickly, too. That rapidly reduces the amount of water in the clouds, and shifts several of their key characteristics from a reflectance point of view.

What's happening inside the clouds also affects their shape, creating further consequences for how well they protect the water underneath.

All these factors need to be weighed up in order to produce climate models that are as accurate as possible.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021AV000454

Comment by Dr. Krishna Kumari Challa on April 20, 2022 at 11:18am

NASA Beamed a Doctor to The ISS in a World-First 'Holoportation' Achievement

There's never been a house call quite like this. In a first for telepresence communication, a NASA flight surgeon was 'holoported' to the International Space Station (ISS), appearing and conversing as a virtual presence in real time, hundreds of miles above the surface of Earth.

 When NASA flight surgeon Josef Schmid was beamed up to the ISS in October of last year, the illusion was made possible thanks to Microsoft's 'holoportation' technology, which lets users interact with 3D representations of remote participants in real time.

Unlike traditional holographic projections that appear to hover in the air for anybody to see, holoportation requires the use of an augmented reality headset, such as Microsoft's HoloLens technology, for the wearer to be able to perceive (and interact with) the remotely captured individual(s), who are filmed with a multiple-camera setup in their actual location.

In this case, European Space Agency (ESA) astronaut Thomas Pesquet, who was on board the ISS and wearing such a headset, had a two-way conversation with Schmid and members of his medical team, along with Fernando De La Pena Llaca, the CEO of AEXA Aerospace, which develops custom holoportation software (the kind that made this ISS session possible).

https://www.sciencealert.com/nasa-surgeon-beamed-to-international-s...

Comment by Dr. Krishna Kumari Challa on April 20, 2022 at 11:08am

Hypersonic Missiles

https://theconversation.com/how-hypersonic-missiles-work-and-the-un...

Comment by Dr. Krishna Kumari Challa on April 20, 2022 at 10:41am

First US trial of GM mosquitoes

The results are in from the first open-air study of genetically engineered mosquitoes in the United States. The British biotechnology company Oxitec, which ran the experiment, reported in a webinar that its insects behaved as planned: bioengineered male Aedes aegypti mosquitoes hatched, spread and mated with the wild population. A survey of more than 20,000 mosquito eggs laid in the area confirmed that all the females that inherited a deadly gene from a bioengineered dad died before they reached adulthood. More research is needed to discover whether the method successfully suppresses the wild population or achieves its ultimate goal of reducing the transmission of diseases carried by the mosquitoes, such as Zika, dengue, chikungunya and yellow fever.

Comment by Dr. Krishna Kumari Challa on April 20, 2022 at 10:34am

Tumors partially destroyed with sound don't come back

Noninvasive sound technology developed recently by researchers breaks down liver tumors in rats, kills cancer cells and spurs the immune system to prevent further spread—an advance that could lead to improved cancer outcomes in humans.

By destroying only 50% to 75% of liver tumor volume, the rats' immune systems were able to clear away the rest, with no evidence of recurrence or metastases in more than 80% animals.

Even if we don't target the entire tumor, we can still cause the tumor to regress and also reduce the risk of future metastasis. 

Results also showed the treatment stimulated the rats' immune responses, possibly contributing to the eventual regression of the untargeted portion of the tumor and preventing further spread of the cancer.

The treatment, called histotripsy, noninvasively focuses ultrasound waves to mechanically destroy target tissue with millimeter precision. The relatively new technique is currently being used in a human liver cancer trial in the United States and Europe.

Tejaswi Worlikar, Man Zhang, Anutosh Ganguly, Timothy L. Hall, Jiaqi Shi, Lili Zhao, Fred T. Lee, Mishal Mendiratta-Lala, Clifford S. Cho, Zhen Xu. Impact of Histotripsy on Development of Intrahepatic Metastases in a Rodent Liver Tumor Model. Cancers, 2022; 14 (7): 1612 DOI: 10.3390/cancers14071612

Comment by Dr. Krishna Kumari Challa on April 20, 2022 at 10:15am

Researchers obtain functional human blood cells via interspecies chimerism

Interspecies chimerism is a phenomenon of an organism consisting of tissue and genetic information from two different species. Currently, many studies investigate the use of interspecies chimerism with human pluripotent stem cells (hPSCs) to generate functional human cells, tissues or organs in large animals, which is expected to solve the shortage of functional tissues and organs for transplant. However, hPSCs interspecies chimerism faces barriers due to the extremely low chimeric contribution of hPSCs.

Recently, research teams led by Prof. Pan Guangjin and Prof. Lai Liangxue from the Guangzhou Institutes of Biomedicine and Health (GIBH) of the Chinese Academy of Sciences (CAS) made new progress on hPSCs interspecies chimerism. They developed an enhanced hPSCs in interspecies chimerism that allows the obtaining of functional human blood cells through interspecies chimerism technology for the first time. The study is published online in Stem Cell Reports.

The teams discovered that the rapid apoptosis  of hPSCs in the interspecies embryos was mainly due to the growth disadvantage and a "loser" state competing with the host animal stem cells. A new factor MYCN combined with anti-apoptotic gene BCL2 effectively overcame apoptosis of hPSCs and markedly promoted chimerism formation.

Strikingly, the teams isolated live human blood progenitor cells from blood-deficient mice through interspecies chimerism using hPSCs for complementation. The obtained cells can be further cultured and differentiated into different blood cells in dish.

This work presents an important method for understanding the interspecies chimerism barrier using hPSCs. The enhanced hPSCs for interspecies chimerism lays the foundation for acquiring human cells, tissues and organs for transplantation purposes in the future.

Yanling Zhu et al, Generating functional cells through enhanced interspecies chimerism with human pluripotent stem cells, Stem Cell Reports (2022). DOI: 10.1016/j.stemcr.2022.03.009

https://phys.org/news/2022-04-functional-human-blood-cells-interspe...

Comment by Dr. Krishna Kumari Challa on April 19, 2022 at 12:02pm

One step closer to creating new hair follicles

In a new study,  researchers take a unique approach to identify the molecular signals that induce a critical trigger for hair follicle formation and regeneration.

The findings could prove crucial for developing new therapies to re-grow hair—and provide a blueprint for unraveling other mysteries of tissue growth at the cellular level.

This is a decades-old problem that has been unsolvable because formation of the dermal condensate, the signaling center that induces the growth and differentiation of hair follicles, has been difficult to visualize and capture due to how rapidly they form.

Dermal condensates (DCs) are densely-packed clusters of cells, located under the skin's outer layer. DCs act as central commanders of hair follicle activity by sending signals to the skin's outer layer, instructing it to form hair follicles and determining follicle size.

Unraveling the steps that induce DC formation has been a major challenge for researchers, because the process is difficult to track over time and tease apart experimentally. Overcoming this barrier could open the door to effective methods for reproducing DCs to test new drugs for hair loss and to generate hair follicles in 3D culture models.

For this study researchers  took a unique approach to study DCs.

Using single-cell RNA-sequencing data from mouse skin, they designed a computational approach to align a series of single-cell profile "snapshots" to reconstruct the time course of DC development. This provided a roadmap that delineates how an immature dermal cell drives itself to maturity. More importantly, the approach allowed the researchers to investigate the molecular signals that serve as engines in the process. By combining their computational findings with in vivo genetic experiments, they were able to pin down the critical signals involved in DC formation.

One of the signals is known as Wnt and the other is called "sonic hedgehog," or SHH. Both signals are considered essential in the development of many tissue types and play a role in regulating adult tissue homeostasis and regeneration. They are also implicated in pathological states such as cancer when they are aberrantly overactivated.

For the study, the researchers were able to genetically modulate these signals to curtail the speed of DC formation, effectively playing out the DC formation process in slow motion.

This work will help pave the way to developing robust methods for recreating DCs in the laboratory, and for adult hair follicle regeneration.

https://medicine.yale.edu/news-article/one-step-closer-to-creating-...

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