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Comment by Dr. Krishna Kumari Challa on September 9, 2021 at 7:06am

Scientists create artificial cells that mimic living cells' ability to capture, process, and expel material

Researchers have developed artificial cell-like structures using inorganic matter that autonomously ingest, process, and push out material—recreating an essential function of living cells.

Their article, published in Nature, provides a blueprint for creating "cell mimics," with potential applications ranging from drug delivery to environmental science.

A fundamental function of living cells is their ability to harvest energy from the environment to pump molecules in and out of their systems. When energy is used to move these molecules from areas of lower concentration to areas of higher concentration, the process is called active transport. Active transport allows cells to take in necessary molecules like glucose or amino acids, store energy, and extract waste.

For decades, researchers have been working to create artificial cells—engineered microscopic structures that emulate the features and behavior of biological cells. But these cell mimics tend to lack the ability to perform complex cellular processes like active transport.

In the Nature study, researchers describe a new, fully synthetic cell mimic that is one step closer to replicating the function of living cells. When deployed in mixtures of different particles, the cell mimics can perform active transport tasks by autonomously capturing, concentrating, storing, and delivering microscopic cargo. These artificial cells are fabricated using minimal ingredients and borrow no materials from biology.

To design the cell mimics, the researchers created a spherical membrane the size of a red blood cell using a polymer, a stand-in for the cellular membrane that controls what goes in and out of a cell. They pierced a microscopic hole into the spherical membrane creating a nano-channel through which matter can be exchanged, imitating a cell's protein channel.

But in order to perform the tasks required for active transport, the cell mimics needed a mechanism to power the cell-like structure to pull in and expel material. In a living cell, mitochondria and ATP provide the necessary energy for active transport. In the cell mimic, the researchers added a chemically reactive component inside the nano-channel that, when activated by light, acts as a pump. When light hits the pump, it triggers a chemical reaction, turning the pump into a tiny vacuum and pulling cargo into the membrane. When the pump is switched off, the cargo is trapped and processed inside the cell mimic. And when the chemical reaction is reversed, the cargo is pushed out on demand.

 Transmembrane transport in inorganic colloidal cell mimics, Nature (2021). DOI: 10.1038/s41586-021-03774-y , www.nature.com/articles/s41586-021-03774-y

https://phys.org/news/2021-09-scientists-artificial-cells-mimic-abi...

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 1:32pm

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 1:30pm

The squid and its giant nerve fibre Part 1

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 1:07pm

NASA Testing Electric 'Air Taxi' Prototype Designed to Carry Passengers in The Sky

NASA is commonly thought of as America's space agency, but its name also emphasizes another research area. The National Aeronautics and Space Administration is also America's civilian aerospace research organization. 

Electric Vertical Take-Off and Landing Aircraft

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 1:01pm

Hundreds of Medical Journals Just United Together to Issue a Brutally Frank Warning

Global warming is already affecting people's health so much that emergency action on climate change cannot be put on hold while the world deals with the COVID-19 pandemic, medical journals across the globe warned on Monday.

Health is already being harmed by global temperature increases and the destruction of the natural world," read an editorial published in more than 220 leading journals ahead of the COP26 climate summit in November.

Since the pre-industrial era, temperatures have risen around 1.1 degrees Celsius.

The editorial, written by the editors-in-chief of over a dozen journals including the Lancet, the East African Medical Journal, Brazil's Revista de Saude Publica and the International Nursing Review, said this had caused a plethora of health problems.

"In the past 20 years, heat-related mortality among people older than 65 years has increased by more than 50 percent," it read.

"Higher temperatures have brought increased dehydration and renal function loss, dermatological malignancies, tropical infections, adverse mental health outcomes, pregnancy complications, allergies, and cardiovascular and pulmonary morbidity and mortality."

It also pointed to the decline in agricultural production, "hampering efforts to reduce undernutrition".

These effects, which hit those most vulnerable like minorities, children, and poorer communities hardest, are just the beginning, it warned.

https://www.bmj.com/content/374/bmj.n1734

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 12:47pm

New Mathematical Solutions to An Old Problem in Astronomy

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 12:38pm

Why are planets round?

 Earth is round. So are other planets in the solar system.

When you drop anything, gravity causes it to fall directly toward the center of the Earth, at least until it hits the ground. Gravity is a force that is caused by nearly everything that has mass. Mass is a measure of how much material there is in anything. It could be in the form of rocks, water, metal, people – anything. Everything material has mass, and therefore everything causes gravity. Gravity always pulls toward the center of mass.

The Earth and all planets are round because when the planets formed, they were composed of molten material – essentially very hot liquid. Since gravity always points toward the center of a mass, it squeezed the stuff the Earth is made of equally in all directions and formed a ball. When the Earth cooled down and became a solid, it was a round ball. If the Earth didn’t spin, then it would have been a perfectly round planet. Scientists call something that is perfectly round in all directions a “sphere.”

The gas cloud that the Earth was made from was slowly rotating in one direction around an axis. The top and bottom of this axis are the north and south poles of Earth.

If you ever played on a merry-go-round, you know that the spinning merry-go-round tends to throw you off. The faster it spins, the harder it is to stay on. This tendency to be flung off is called centrifugal force and pushes the mass on the equator outward. This makes the planet bulge at the equator.

The faster the spin, the more unround it becomes. Then, when it cools and hardens, it retains that shape. If a molten planet starts off spinning faster, it would be less round and have a bigger bulge.

The planet Saturn is very oblate – non-spherical – because it rotates very fast. Because of gravity, all planets are round, and because they rotate at different rates, some have fatter equators than their poles. So the shape of the planet and the speed and direction that it rotates depends on the initial condition of the material out of which it forms.

https://theconversation.com/why-are-planets-round-164903?utm_medium...

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 12:24pm

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 12:07pm

 Fridge-free COVID-19 vaccines  grown in plants and bacteria

Nanoengineers have developed COVID-19 vaccine candidates that can take the heat. Their key ingredients? Viruses from plants or bacteria.

The new fridge-free COVID-19 vaccines are still in the early stage of development. In mice, the vaccine candidates triggered high production of neutralizing antibodies against SARS-CoV-2, the virus that causes COVID-19. If they prove to be safe and effective in people, the vaccines could be a big game changer for global distribution efforts, including those in rural areas or resource-poor communities.

What's exciting about this vaccine technology is that is thermally stable, so it could easily reach places where setting up ultra-low temperature freezers, or having trucks drive around with these freezers, is not going to be possible.

The researchers created two COVID-19 vaccine candidates. One is made from a plant virus, called cowpea mosaic virus. The other is made from a bacterial virus, or bacteriophage, called Q beta.

Both vaccines were made using similar recipes. The researchers used cowpea plants and E. coli bacteria to grow millions of copies of the plant virus and bacteriophage, respectively, in the form of ball-shaped nanoparticles. The researchers harvested these nanoparticles and then attached a small piece of the SARS-CoV-2 spike protein to the surface. The finished products look like an infectious virus so the immune system can recognize them, but they are not infectious in animals and humans. The small piece of the spike protein attached to the surface is what stimulates the body to generate an immune response against the coronavirus.

The researchers note several advantages of using plant viruses and bacteriophages to make their vaccines. For one, they can be easy and inexpensive to produce at large scales.

Another big advantage is that the plant virus and bacteriophage nanoparticles are extremely stable at high temperatures. As a result, the vaccines can be stored and shipped without needing to be kept cold. 

Trivalent subunit vaccine candidates for COVID-19 and their delivery devices, Journal of the American Chemical Society (2021). DOI: 10.1021/jacs.1c06600

https://phys.org/news/2021-09-fridge-free-covid-vaccines-grown-bact...

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 11:30am

Cavendish Gravity Experiment

A qualitative demonstration of universal gravitation using a torsion balance.

The Cavendish Experiment Explained

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