There's oxygen on Rhea, but aliens? Don't hold your breath

(Image: NASA/JPL/Space Science Institute)

On its journey around Saturn and its moons, the Cassini mission - jointly run by NASA and the European Space Agency - has made another breathtaking discovery. The findings, published in Science (DOI: 10.1126/science.1198366), show that Rhea, the second biggest moon of the giant planet, has an atmosphere that is 70 per cent oxygen and 30 per cent carbon dioxide. This adds to the picture of Rhea that Cassini has already provided by imaging its craters anddiscovering its rings.

"This really is the first time that we've seen oxygen directly in the atmosphere of another world", Andrew Coates, from University College London's Mullard Space Science Laboratory, told The Guardian. Layers containing oxygen had already been detected around the Jovian moons Europa and Ganymede in the 1990s, but only from a distance using NASA's Hubble Space Telescope.

This time, Cassini's instrument had the chance to "smell" that oxygen, as it flew through it over Rhea's north pole, just 97 kilometres above the surface, according to the details given on Space.com. This layer - with an oxygen density probably about 5 trillion times less than on Earth - was "too thin to be remotely detected", said Ben Teolis of the Southwest Research Institute in San Antonio.

So where could this oxygen come from? "As the magnetic field rotates around Saturn, particles carried in the field slam into the hemisphere of Rhea that's facing their flow," Teolis told BBC News. "They hit that hemisphere and break water molecules on the surface. The atoms are then rearranging themselves to make oxygen molecules, which are sputtered from the surface by additional impacting particles." That process is likely to be ongoing, with the oxygen molecules created being constantly whipped out into space.

According to Teolis, "the new results suggest that active, complex chemistry involving oxygen may be quite common throughout the solar system and even our universe". Bad news for alien hunters, though, concludes Wired magazine."All evidence from Cassini indicates Rhea is too cold and devoid of liquid water necessary for life as we know it," Teolis told them.

Skin patch could offer pain relief with every flinch

A SKIN patch could soon provide efficient pain relief whenever you flex sore muscles. The system would work by synchronising the release of drugs with movement of the underlying inflamed tissue.

The system could synchronise the release of drugs with movement of the inflamed muscle

Unyong Jeong's team at Yonsei University in Seoul, South Korea, covered a flexible rubber film with a sheet of corrugated microporous polystyrene, with gutters around 3 micrometres wide and 1 micrometre deep. The gutters were then filled with a liquid and sealed with another rubber film. Finally, the first rubber film was peeled away to expose the underside of the liquid-filled polystyrene gutters. Flexing the patch distorts the polystyrene tunnels enough to reduce their volume, squeezing the solution out through the pores in the plastic. Once the strain is removed, the tunnels spring back into shape, ready for the next use (Angewandte Chemie, DOI: 10.1002/anie.201004838).

Jeong and his team demonstrated the mechanism with a dye solution, but they are now moving on to therapeutic applications.

He envisages the first practical use will be skin patches for treating muscle pain and rheumatism. "Current [skin patches] are designed to just continuously release the active agents," he says. "If we can control the release rate responding to the motion of our muscles, it will make the patches more effective and prolong the time of use." He is also hoping to develop biodegradable strain-release patches to heal organs and damaged muscles inside the body.

Mauro Ferrari of the Methodist Hospital Research Institute in Houston, Texas, says the idea is clever. "I've never seen anything like it," he adds.

92 Years Later, A Sickle-Cell Surprise

Dr. Jeffrey Taubenberger of the National Institutes of Health looked into a microscope this summer and saw something unexpected. He had been looking for evidence of a flu virus. Instead, he found the earliest known proof of sickle-cell anemia. Host Liane Hansen interviews Maryn McKenna ofWired magazine about the chance discovery of the first tissue sample of sickle-cell anemia.




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New discovery in the fight against Huntington’s disease

Scientists have made a novel discovery in the fight against Huntington’s disease (HD).

HD is an incurable progressive neurodegenerative genetic disorder which affects motor coordination and leads to cognitive decline and dementia.

The disease pathology stems from a mutation in the huntingtin (Htt) gene, which results in the accumulation of toxic proteins leading to neuronal cell death.

Previous studies have clearly implicated caspases – enzymes that break down cells – as key players in the cascade of events involved in HD neuronal death.

Now scientists have identified three small molecules that inhibit the activity of those caspases, suppressing toxicity and rescuing neurons from cell death in cell culture.

The research was led by both Buck Institute faculty member Lisa Ellerby, and Yale University faculty member Jonathan Ellman. Dr. Ellerby is doing follow up studies in a mouse model of the disease.

Dr. Ellerby said a substrate based screening method was used to identify compounds that reacted with caspases. Based on those reactions, Jonathan Ellman, from the Yale University Department of Chemistry, converted the compounds to caspase inhibitors.

Dr. Ellerby said that the inhibitors are based on properties of a drug, which had entered Phase I clinical trials for the treatment of human liver preservation injury.

“These molecules shows particular promise. They cross the blood-brain barrier and acts selectively to block the processes involved in HD,” said Ellerby.

Dr. Ellerby said the caspase inhibitors both suppressed the proteolysis of Htt and rescued HD neurons that have begun to undergo cell death.

“We believe this is going to help us move the field forward because now we can test these compounds in live animals. Up until this point we have not identified a caspase inhibitor that has acted selectively against the toxic effects of the Htt mutation,” said Dr. Ellerby.

The study appears in the November 24th edition of Chemistry and Biology. (ANI)

Scientists image hydrogen atom directly for the first time

Research team takes image of hydrogen atom

Kyodo News

A research team led by Yuichi Ikuhara, a professor of material science at the University of Tokyo, said Thursday they have succeeded in taking an image of a single hydrogen atom, the smallest and lightest of the chemical elements.

Nothing tinier: An arrow points at an image of a single hydrogen atom in this photo supplied by University of Tokyo professor Yuichi Ikuhara. KYODO PHOTO

Although it had been thought acquiring direct images of a hydrogen atom, whose diameter is about one-ten-millionth of a millimeter, was impossible, the team managed the feat with a state-of-the-art "scanning transmission electron microscope" while examining vanadium hydride, a hydrogen storage material.

The microscope scanned an electron beam onto a tiny spot, placed at a theoretically calculated location, on the specimen to enable a detector to catch and film the image of the hydrogen atom as well as the vanadium atom.

The same method can be used to take images of atoms of various kinds of specimens, according to the team. Earlier means of taking images of a hydrogen atom involved indirect methods, like image processing.

A technique for viewing a single hydrogen atom had been sought amid active research on hydrogen storage materials as a clean source of energy.

"Now we can view all atoms that exist in the world," Ikuhara said. "This will be a breakthrough toward future manufacturing that will be compelled to involve consideration of each individual atom and molecule."