Synlight
23-Mar-2017: Scientists switched on The World's Largest "Artificial Sun"
Scientists in Germany have switched on the world’s largest artificial Sun "synlight" for the first time. It's located in Jülich, Germany and operated by the German Aerospace Center (DLR).
“Synlight” uses 149 xenon lamps to recreate the light from the Sun onto a single point, vaporizing water and producing hydrogen and oxygen. The huge machine towers 14 meters (45 feet) high and 16 meters (52 feet) across, and produces temperatures of up to 3,000°C (5,400°F) focused on a single spot 20 by 20 centimeters (8 by 8 inches). This particular test lasted just 15 to 20 minutes, producing a tiny amount of hydrogen, but the lamps can theoretically be run continuously for hours or even a day.
The lamps have an output of 350 kilowatts, and supposedly produce 10,000 times the intensity of solar radiation on Earth. Its spectrum of UV radiation is similar to that of the Sun. When focused onto a metal sheet in a small reactor device, it splits water up into hydrogen and oxygen.
Synlight's goal is to replicate the process using sunlight to produce usable amounts of hydrogen.
Li-Fi
18-Mar-2017: 'Li-Fi' LED light bulbs to transmit wireless data at gigabit-level speeds
Researchers have devised a new method that relies on central 'light antennas' to beam rays of different wavelengths to wireless devices - meaning networks won't get jammed by several competing devices.
A light-based system 'Li-Fi,' could make wireless networks much more secure. It can transmit at the speed of 40 Gbit/s per ray. It would rely on direct rays of light from an optical fiber, and as it has no moving parts, it would be a maintenance free system that requires no power.
The direction of the ray of light can also be changed by adjusting the wavelength. The light-based network can track the precise location of each wireless device based on its radio signal. To add more devices, different wavelength can be assigned from the same antenna.
While current Wi-Fi systems rely on radio signals with a frequency of 2.5 or 5 gigahertz, the new network would use infrared light with wavelengths of 1500 nanometers or more. According to the researchers, this light can achieve much higher frequencies - up to 200 terahertz - for much greater capacity.
The system also uses visible light communication between 400 and 800 terahertz to transmit messages in binary code. Visible light cannot pass through walls, making Li-Fi a much more secure system, and less susceptible to interference.
While the system seems promising, it won't likely replace Wi-Fi entirely, at least not anytime soon. Instead, researchers are now looking to retrofit devices with Li-Fi to use the two wireless systems together to optimize speed and security.
GABA (gamma aminobutyric acid)
23-Mar-2017: Zebrafish could be a clue to Cure Blindness
Zebrafish are only a few centimeters long, but they’ve got some supersized powers. When their hearts or brains are damaged, they regenerate. When their fins are cut off, they grow back. When they are blinded, they can regain the ability to see. It’s this last ability that’s the subject of some potentially groundbreaking new research.
Vanderbilt scientists may have discovered the key to zebrafish retina regeneration. If the process can be replicated in humans, it stands to power new treatments for blindness caused by retinal disease and injury.
Zebrafish retina can be damaged to cause blindness yet it only takes about three to four weeks before vision is restored. Zebrafish breed easily in captivity, grow quickly, and as babies are completely transparent, it makes it easy to study their organs. As they share 70 percent of humans' genetic code, it’s often possible to use them to study human genetic traits and diseases.
The structure and cell types of zebrafish retinas are almost identical to those of humans. Each contain three layers of nerve cells: light-detecting photoreceptors, signal-integrating horizontal cells, and ganglion cells that pass visual information on to the brain.
Retinal damage is behind many of the leading causes of blindness in the developed world. These causes include macular degeneration, an often age-related disease in which part of the retina becomes damaged, causing blurring and blank spots in vision; diabetic retinopathy, where diabetes damages the blood vessels in the retina; and retinitis pigmentosa, a genetic condition causing degeneration of the retina’s rod photoreceptor cells. Since human retinas do not regenerate, any retinal damage caused by disease or injury is permanent.
Previous studies have suggested that growth factors secreted by dying photoreceptors in the fishes’ eyes might start the process, sparking stem cells in the eyes to begin dedifferentiating (going back to an earlier developmental stage) and then differentiating into new retina cells. But Mahesh Rao, one of Patton’s graduate students, got the idea to look at the neurotransmitter GABA, a chemical messenger in the brain that reduces the activity of neurons, noting that GABA had been found to control stem cell activity in mice brains.
The team tested Rao’s idea by blinding zebrafish—this can be done by putting them in darkness for a few days, then exposing them to bright light—then giving them GABA-stimulating drugs. They also gave GABA-lowering drugs to normally sighted zebrafish. They found that the blind fish given GABA-stimulating drugs could not regenerate their retinas normally, while the normal fish with lowered GABA levels began regenerating their retinas. This suggested that it was, indeed, a lowered concentration of GABA that started the retina regeneration process.
The team is beginning to test the GABA theory on mice. If that works, it will be on to human trials, testing whether GABA inhibitors can stimulate retina regeneration.