邯郸玛丽亚医院四维(邯郸月经量少晚上没有) (今日更新中)

LOS ANGELES, May 1 (Xinhua) -- Middle-aged adults who sleep too less or too much may be more likely to suffer cognitive decline, a new study suggests.According to the study, less than six hours of sleep each night is considered too little and more than eight hours as too much for middle-aged adults.The study, conducted by researchers at University College London Medical School, was published May 1 in the American medical journal Sleep.The researchers conducted the study in two periods -- the 1997- 1999 period and the 2003-2004 period. The participants were asked how many hours they slept on an average week night, and were asked the same question in 2003-2004 after an average 5.4 years of follow-up.The researchers compared those who reported changes in their sleep patterns with people whose sleep duration stayed the same over the course of the study.In the follow-up, each individual was given a battery of standard tests to assess his or her memory, reasoning, vocabulary, global cognitive status and verbal fluency.The study findings show that women who slept seven hours per night had the highest score for every cognitive measure, followed by those who had six hours of sleep. For men, cognitive function was similar for those who reported sleeping six, seven or eight hours.However, less than six hours of sleep -- or more than eight hours -- were associated with lower scores."Sleep provides the body with its daily need for physiological restitution and recovery," explained Jane Ferrie, a senior research fellow in the department of epidemiology and public health at the school. "While seven hours a night appears to be optimal for the majority of human beings, many people can function perfectly well on regular sleep of less or more hours."However, since most research has focused on the effects of sleep deprivation on biological systems, it is not yet fully understood why seven hours is optimal -- or why long sleeping appears to be detrimental, Ferrie said."Chronic short sleep produces hormones and chemicals in the body which increase the risk of developing heart disease and strokes, and other conditions like high blood pressure and cholesterol, diabetes and obesity," she added.

BEIJING, Jan. 24 (Xinhua) -- Chinese Premier Wen Jiabao called on the public to give suggestions on the government work during his visit to central China's Henan Province on Friday and Saturday.Wen visited urban communities and villages in Henan to hear citizens' voices, to prepare for the Report on the Work of the Government, which he will deliver at the National People's Congress in March.He made his first stop at a renovated shanty-town in the city of Hebi, an industrial city reliant on coal mining.Wen visited the family of Song Helian, a factory worker who has just moved from a 50-square-meter room to a three-bedroom apartment.Chinese Premier Wen Jiabao (R, front), who is also a member of the Standing Committee of the Political Bureau of the Communist Party of China (CPC) Central Committee, attends a symposium in Hebi, central China's Henan Province, Jan. 21, 2011. Wen Jiabao visited urban communities and villages in Henan on Jan. 21 and 22 to hear citizens' voices, to prepare for the Report on the Work of the Government, which he will deliver at the National People's Congress in March. He told local cadres the renovation of shantytowns has a direct bearing on people's livelihoods and must be carried out successfully.During his meeting with residents of a community, Wen told them, "The job of the government is to serve the people and to secure a better life for the people. You are in the best position to criticize the government's work report and the next five-year plan."The residents and Wen talked about recent price rises, medical insurance and employment for laid-off workers among other things.During a visit to a village, Wen met with villagers and stressed the importance of agricultural technology.Wen also called for greater efforts to improve rural health facilities.

WASHINGTON, May 27 (Xinhua) -- Two U.S. astronauts conducted the fourth and final scheduled spacewalks for space shuttle Endeavour 's STS-134 mission on Friday morning, the U.S. National Aeronautics and Space Administration (NASA) announced.The seven-hour, 24-minute spacewalk completed by Mike Fincke and Greg Chamitoff at 7:39 a.m. EDT (1139 GMT) was the final spacewalk conducted by space shuttle astronauts before NASA turns over Endeavour and sister ships Discovery and Atlantis to museums. Space station crew will continue to make spacewalks for maintenance and repair tasks.At 5:02 a.m. (0902 GMT), Fincke and Chamitoff surpassed the 1, 000th hour astronauts and cosmonauts have spent spacewalking in support of space station assembly and maintenance. The milestone occurred four hours and 47 minutes into the spacewalk, the 159th in support of station assembly and maintenance, totaling 1,002 hours, 37 minutes.The astronauts completed their mission to stow the 50-foot-long boom on the station truss and work on some new installations to extend the space station's robotic arm. After that, shuttle commander Mark Kelly called Mission Control in Houston to mark the milestone -- after 12 years of efforts."Space station assembly is complete," Kelly said.It was the 248th spacewalk U.S. astronauts have conducted and the 118th from space station airlocks. Landing is scheduled for 2: 32 a.m. EDT (0632 GMT) on Wednesday at the Kennedy Space Center in Florida. Shuttle Atlantis is targeted to launch on July 8 for space shuttle's final flight.Endeavour lifted off on May 16 from the Kennedy Space Center in Florida, to deliver to the International Space Station a 2-billion- dollar, multinational particle detector known as the Alpha Magnetic Spectrometer (AMS).AMS, a particle physics detector, is designed to search for various types of unusual matter by measuring cosmic rays. Its experiments are designed to help researchers study the formation of the universe and search for evidence of dark matter, strange matter and antimatter.NASA's 30-year-old shuttle program is ending due to high operating costs. The Obama administration wants to spur private companies to get into the space taxi business, freeing NASA to focus on deep space exploration and new technology development.When the U.S. space shuttle program officially ends later this year, the Russian space program's Soyuz capsule will be the only method for transporting astronauts to and from the station.

BEIJING, April 12 (Xinhuanet) -- The elderly have a difficult time with multi-tasking as a study suggests that older brains behave differently when it comes to switching between two tasks, according to media reports on Tuesday.Researchers used functional magnetic resonance imaging (FMRI) to analyze brain activity in 20 people over age 60 by asking them to contemplate outdoor photos shown briefly. Then the elderly were presented with the picture of a face and asked to determine its gender and age, before being asked to recall details from the original scene they viewed.Researchers then compared their results to a similar experiment with 20 younger adults and found the brains of older subjects were less capable of disengaging from the interruption and reestablishing the neural connections necessary to switch back to focusing on the original memory."Unlike younger individuals, older adults failed to both disengage from the interruption and re-establish functional connections associated with the disrupted memory network," write Wesley C. Clapp of the University of California, San Francisco, and colleagues in the Proceedings of the National Academy of Sciences.The study, published in the online edition of the journal Proceedings of the National Academy of Sciences, sheds new lights into a growing body of studies showing that one's ability to move from one task to another in quick succession becomes more difficult with age.

WASHINGTON, May 20 (Xinhua) -- Two U.S. astronauts conducted the first of four spacewalks for space shuttle Endeavour's STS-134 mission on Friday morning, the U.S. National Aeronautics and Space Administration (NASA) said.According to the U.S. space agency, Endeavour's mission specialists Andrew Feustel and Greg Chamitoff completed the six-hour, 19-minute spacewalk at 9:29 a.m. EDT (1329 GMT). They successfully installed antennas for the External Wireless Communication system, routing cables, setting up the antenna, installing handrails, and connecting power cables.Because of a carbon dioxide sensor failure in Chamitoff's spacesuit, flight controllers limited his spacewalk time to about six hours 20 minutes, 10 minutes less than the planned six hours and 30 minutes. There was no indication his suit's carbon dioxide levels would rise. However, they deferred tasks to remove a micrometeoroid debris shield to access and attach some of the connection points.This was the 245th spacewalk conducted by U.S. astronauts. It was Feustel's fourth spacewalk for a total time of 27 hours and 17 minutes, and Chamitoff's first.Endeavour lifted off on Monday morning from Kennedy Space Center in Florida, to deliver to the International Space Station a 2-billion-dollar, multinational particle detector known as the Alpha Magnetic Spectrometer (AMS).AMS, a particle physics detector, is designed to search for various types of unusual matter by measuring cosmic rays. Its experiments are designed to help researchers study the formation of the universe and search for evidence of dark matter, strange matter and antimatter.

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