Duke University chemists say they’ve come up with a way to grow carbon nanotubes — a.k.a. Buckytubes — that vary in size far less than those produced previously. The technique could help with the development of nanostructures with electronic properties reliable enough to use in molecular-sized circuits.
Until now, astronomers haven’t been able to offer a full explanation for why the Milky Way and other galaxies produce new stars at a relative snail’s pace. While they have known for decades that high turbulence keeps huge clouds of hydrogen gas from condensing into stars, they haven’t identified all the causes of the galactic perturbations. In a coming report researchers in San Diego say they have discovered that a well-known, but overlooked source of heating?regular outbursts of ultraviolet radiation from clusters of very large, bright stars?may play a significant role in keeping the Milky Way’s gas continually stirred up.
Using a common diabetes drug, researchers in Los Angeles have successfully treated pituitary tumors that cause a potentially life-threatening condition known as Cushing’s syndrome. The most common type of Cushing’s syndrome is caused by prolonged high-level exposure of a hormone called ACTH (adrenocorticotropin), which is secreted in excess by tumors of the pituitary gland, situated at the base of the brain and, which controls growth, metabolism and reproduction. Although the disorder is rare, it affects more women than men by a ratio of 5:1. Symptoms include weight gain with rounding of the face; increased fat in the neck; thinning skin; excess hair growth on the face neck, chest abdomen and thighs; muscle weakness and bone loss (osteoporosis); high blood sugar; diabetes; and high blood pressure.
A new moon of the planet Uranus has been discovered and confirmed by a team of astronomers at NASA’s Jet Propulsion Laboratory. This most-recently discovered natural satellite, named S/2001 U 1, brings the total number of confirmed uranian moons to 21. The new kid on the block — and five others like it — have very irregular, eccentric orbits that don’t share the same orbital plane as the larger moons of Uranus. Ranging in size from 10 to 20 kilometers, these moons are thought to be remnants of ancient collisions that occurred at the early stage of planetary formation.
Aluminum — one of nature’s best conductors of electricity conductors of electricity — may behave like a ceramic or a semiconductor in certain situations, according to an Ohio State University scientist and his colleagues. Among the findings that appear in the current issue of the journal Science: When it comes to forming tiny structures in computer chip circuits and nanotechnology, aluminum may endure mechanical stress more than 30 percent better than copper, which is normally considered to be the stiffer metal
New evidence from NASA’s Chandra X-ray Observatory challenges an alternative theory of gravity that eliminates the need for dark matter. The observation also narrows the field for competing forms of dark matter, the elusive material thought to be the dominant form of matter in the universe. An observation of the galaxy NGC 720 shows it is enveloped in a slightly flattened, or ellipsoidal cloud of hot gas that has an orientation different from that of the optical image of the galaxy. The flattening is too large to be explained by theories in which stars and gas are assumed to contain most of the mass in the galaxy. “The shape and orientation of the hot gas cloud require it to be confined by an egg-shaped dark matter halo,” said a researcher involved in the stoudy. “This means that dark matter is not just an illusion due to a shortcoming of the standard theory of gravity ? it is real.”