宜宾开眼角术后恢复(宜宾隆鼻多少钱一针) (今日更新中)

WASHINGTON, Aug. 4 (Xinhua) -- Observations from NASA's Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars, the U.S. National Aeronautics and Space Administration (NASA) announced Thursday.Dark, finger-like features appear and extend down some Martian slopes during late spring through summer, fade in winter, and return during the next spring. Repeated observations have tracked the seasonal changes in these recurring features on several steep slopes in the middle latitudes of Mars' southern hemisphere."The best explanation for these observations so far is the flow of briny water," said Alfred McEwen of the University of Arizona, Tucson.McEwen is the principal investigator for the orbiter's High Resolution Imaging Science Experiment and lead author of a report about the recurring flows to be published in Friday's edition of the journal Science.Seven such sites on the planet have been confirmed, with 20 more possible, McEwen said."What makes these new observations so interesting is they occur at much lower latitudes where temperatures are much warmer and where it's actually possible for liquid water to exist," said Arizona State University geophysicist Phil Christensen, one of the scientists who studied the images beamed back from the orbiter.The study does not prove water exists, but identifies it as the best explanation. It's worthwhile to think about alternative reasons for these observations, but none seems to fit as well as briny water, McEwen said."I think it's going to be laboratory experiments on Earth that give us the best confirmation or refutation," he said.

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."

COPENHAGEN, May 30 (Xinhua) -- The number of confirmed E. coli cases has risen to 14 in Denmark, with at least 26 others suspected of having the intestinal infection, the National Serum Institute said Monday.Seven of the confirmed cases show symptoms of kidney failure which marks an advanced stage of the sickness, the institute said."Almost all of the 14 infected people have been in northern Germany recently except just one. There is a 24-year-old man from Jutland. He has not even been to Germany, so he does not quite fit with the rest of the pattern," said Kaare Moelbak, chief physician at the institute. "We do not know yet how he has been so unlucky to get this infection but we assume that it has been a person-to-person transmission, or that he has eaten infected vegetables," he added.Denmark's Veterinary and Food Administration (DVFA) had advised Danish consumers not to eat raw tomato, lettuce and cucumber from Germany, and cucumber from Spain.It is now checking Danish cucumbers for traces of E. coli, with results expected on Tuesday.

WASHINGTON, Sept. 15 (Xinhua) -- A team of researchers has discovered a planet that orbits around a pair of stars, the U.S. space agency NASA announced Thursday.This is the first instance of astronomers finding direct evidence of a so-called circumbinary planet. A few other planets have been suspected of orbiting around both members of a dual-star system, but the transits of the circumbinary planet have never been detected previously.The team, led by Laurance Doyle of the SETI Institute in California, used photometric data from the NASA Kepler space telescope, which monitors the brightness of 155,000 stars.NASA's Kepler mission has discovered a world where two suns set over the horizon instead of just one. The planet, called Kepler-16b, is the most "Tatooine-like" planet yet found in our galaxy. Tatooine is the name of Luke Skywalker's home world in the science fiction movie Star Wars. In this case, the planet it not thought to be habitable. It is a cold world, with a gaseous surface, but like Tatooine, it circles two stars.They found the binary star system by detecting a system where the stars eclipsed each other from the perspective of the Kepler spacecraft. These stars have two eclipses: A primary eclipse when the larger star is partially blocked by the smaller star and a secondary eclipse where the smaller star is fully blocked by the larger star.But the researchers also noticed other times when the brightness of the two stars dropped, even when they were not in an eclipse position. This pattern suggested that there was likely a third object involved. The fact that these so-called tertiary and quaternary eclipses recurred after varying intervals of time, and were of different depths, indicated that the stars were in different positions in their orbit at each instance. This result showed that the tertiary and quaternary eclipses were being caused by something circling both stars, and not an object circling one or the other star.Measurements of the variations in the timing of all four types of eclipses, resulting from the mutual gravitational interactions of the two stars and the third body, demonstrated that the third object was, indeed, a planet. Their work indicates that the planet is less massive than Jupiter, possibly comparable in mass to Saturn, and that the larger of the two binary stars is smaller than our Sun.Their findings will be published Friday in Science."This discovery confirms a new class of planetary systems that could harbor life," Kepler principal investigator William Borucki said in a statement. "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now."

BEIJING, August 3 (Xinhuanet) -- Women who experience any form of gender-based violence are at greater risk of mental health disorders and related dysfunction and disability, according to Australian researchers Wednesday.Those who'd been through at least one form of this abuse -- which includes intimate partner violence, rape, sexual assault, or stalking -- were almost three times more likely to experience a mental health condition than those who were never victimized, according to Susan Rees, PhD of the University of New South Wales in Sydney, Australia, and her colleagues.Those who'd experienced three or four forms had an 11-fold greater risk, reported in the Aug. 3 issue of the Journal of the American Medical Association.The study "reveals a pattern of social disadvantage, disability, and impaired quality of life among women who have experienced gender-based violence," the researchers wrote.

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