北京痛风能吃的有哪些水果(山东艾灸能缓解痛风吗) (今日更新中)

BEIJING, Sept. 6 (Xinhuanet) -- Scientists from Tufts University of the U.S. have created the world's smallest electrical motor in a single molecule.The finding was published in the journal Nature Nanotechnology on Monday.In the research, scientist successfully made a single molecule accept an electrical charge and rotate as fast as 120 revolutions per second."This is the first time that electrically-driven molecular motors have been demonstrated, despite a few theoretical proposals," said Charles H. Sykes, professor of chemistry at Tufts who led the team.The single molecule electric motor could lead to new types of electrical circuitry, giving hope for scientists to apply it in medicine and engineering, he said."The next thing to do is to couple it to other molecules, lining them up next to one another so they're like miniature cog-wheels, and then watch the rotation propagation down the chain," said Sykes.

WASHINGTON, June 9 (Xinhua) -- Observations from NASA's Voyager spacecraft suggest the edge of our solar system may not be smooth, but filled with a turbulent sea of magnetic bubbles, the U.S. space agency said Thursday in a statement.While using a new computer model to analyze Voyager data, scientists found the sun's distant magnetic field is made up of bubbles approximately 100 million miles wide. The bubbles are created when magnetic field lines reorganize. The new model suggests the field lines are broken up into self-contained structures disconnected from the solar magnetic field. The findings are described Thursday in the Astrophysical Journal.Like Earth, our sun has a magnetic field with a north pole and a south pole. The field lines are stretched outward by the solar wind or a stream of charged particles emanating from the star that interacts with material expelled from others in our corner of the Milky Way galaxy.The Voyager spacecraft, more than nine billion miles away from Earth, are traveling in a boundary region. In that area, the solar wind and magnetic field are affected by material expelled from other stars in our corner of the Milky Way galaxy."The sun's magnetic field extends all the way to the edge of the solar system," said astronomer Merav Opher of Boston University. "Because the sun spins, its magnetic field becomes twisted and wrinkled, a bit like a ballerina's skirt. Far, far away from the sun, where the Voyagers are, the folds of the skirt bunch up."Understanding the structure of the sun's magnetic field will allow scientists to explain how galactic cosmic rays enter our solar system and help define how the star interacts with the rest of the galaxy.So far, much of the evidence for the existence of the bubbles originates from an instrument aboard the spacecraft that measures energetic particles. Investigators are studying more information and hoping to find signatures of the bubbles in the Voyager magnetic field data."We are still trying to wrap our minds around the implications of the findings," said University of Maryland physicist Jim Drake, one of Opher's colleagues.Launched in 1977, the Voyager twin spacecraft have been on a 33- year journey. They are en route to reach the edge of interstellar space. NASA's Jet Propulsion Laboratory built the spacecraft and continues to operate them.

BEIJING, Sept. 2 (Xinhuanet) -- The amount of space junk orbiting the Earth could cause fatal leaks in spaceships or destroy valuable satellites, according to a report released by the U.S. National Research Council.Computer models have shown that the number of orbital debris "has reached a tipping point, with enough currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures," the Research Council said Thursday.So far, there are 22,000 pieces of debris large enough to track from the ground, but smaller objects could still cause serious damage.New international regulations are needed to limit space junk.And more researches should be done to test the possible use of launching magnetic nets or giant umbrellas to push the debris further towards the Earth where it would burn up, or into a higher but safer orbit.

WASHINGTON, Sept. 12 (Xinhua) -- An enzyme that appears to play a role in controlling the brain's response to nicotine and alcohol in mice might be a promising target for a drug that simultaneously would treat nicotine addiction and alcohol abuse in people, U.S. researchers find.Over the course of four weeks, mice genetically engineered to lack the gene for protein kinase C (PKC) epsilon consumed less of a nicotine-containing water solution than normal mice, and were less likely to return to a chamber in which they had been given nicotine. In contrast, normal mice steadily increased their consumption of nicotine solution while the mice lacking PKC epsilon did not.The study conducted by researchers at the Ernest Gallo Clinic and Research Center, affiliated with the University of California, San Francisco, appeared Monday in the online edition of the Proceedings of the National Academy of Sciences.In normal mice, as in humans, nicotine binds to a certain class of nicotinic receptors located on dopamine neurons, which causes dopamine to be released in the brain. Dopamine creates a feeling of enjoyment, and thus prompts a sense of reward. Researchers found that mice lacking PKC epsilon are deficient in these nicotinic receptors.The finding complements earlier research in which researchers found that mice genetically engineered to lack the PKC epsilon enzyme drank less alcohol than normal mice and were disinclined to return to a chamber in which they had been given alcohol."This could mean that these mice might not get the same sense of reward from nicotine or alcohol," said Gallo senior associate director and investigator Robert Messing. "The enzyme looks like it regulates the part of the reward system that involves these nicotinic receptors."The reward system is a complex of areas in the brain that affect craving for nicotine, alcohol and other addictive substances.The next step in the research, said Messing, would be to develop compounds that inhibit PKC epsilon. The ultimate goal, he added, would be medications that could be used "to take the edge off of addiction by helping people get over some of their reward craving."

WASHINGTON, July 27 (Xinhua) -- Astronomers studying observations taken by NASA's Wide-field Infrared Survey Explorer (WISE) mission have discovered the first known "Trojan" asteroid orbiting the sun along with Earth, the U.S. National Aeronautics and Space Administration (NASA) announced Wednesday in a statement.Trojans are asteroids that share an orbit with a planet near stable points in front of or behind the planet. Because they constantly lead or follow in the same orbit as the planet, they never can collide with it. In our solar system, Trojans also share orbits with Neptune, Mars and Jupiter. Two of Saturn's moons share orbits with Trojans.Scientists had predicted Earth should have Trojans, but they have been difficult to find because they are relatively small and appear near the sun from Earth's point of view."These asteroids dwell mostly in the daylight, making them very hard to see," said Martin Connors of Athabasca University in Canada, lead author of a new paper on the discovery to be published Thursday in the journal Nature. "But we finally found one, because the object has an unusual orbit that takes it farther away from the sun than what is typical for Trojans. WISE was a game-changer, giving us a point of view difficult to have at Earth 's surface."The WISE telescope scanned the entire sky in infrared light from January 2010 to February 2011. Connors and his team began their search for an Earth Trojan using data from NEOWISE, an addition to the WISE mission that focused in part on near-Earth objects, or NEOs, such as asteroids and comets. NEOs are bodies that pass within 28 million miles (45 million kilometers) of Earth 's path around the sun. The NEOWISE project observed more than 155, 000 asteroids in the main belt between Mars and Jupiter, and more than 500 NEOs, discovering 132 that were previously unknown.The team's hunt resulted in two Trojan candidates. One called 2010 TK7 was confirmed as an Earth Trojan after follow-up observations with the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii.The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth's orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth. The asteroid's orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers).

来源：资阳报