宜宾开眼角双眼皮手术(宜宾开眼角术) (今日更新中)

WASHINGTON, Aug. 2 (Xinhua) -- The weakness of aging is associated with leaky calcium channels inside muscle cells and a drug already in Phase II clinical trials for the treatment of heart failure might plug those leaks, according to a report published Tuesday in the online edition of Cell Metabolism.Earlier studies by the research team led by Andrew Marks of Columbia University showed the same leaks underlie the weakness and fatigue that come with heart failure and Duchenne muscular dystrophy."It's interesting, normal people essentially acquire a form of muscular dystrophy with age," Marks said. "The basis for muscle weakness is the same." Extreme exercise like that done by marathon runners also springs the same sort of leaks, he added, but in that case damaged muscles return to normal after a few days of rest. A microscopic view shows smooth muscle cells derived from human embryonic stem cells showing the nuclei (blue) and proteins of the cytoskeleton (green) in this handout photo released to Reuters by the California Institute for Regenerative Medicine, March 9, 2009The leaks occur in a calcium release channel called ryanodine receptor 1 (RyR1) that is required for muscles to contract. Under conditions of stress, those channels are chemically modified and lose a stabilizing subunit known as calstabin1.Calcium inside of muscle cells is usually kept contained. When it is allowed to leak out into the cell that calcium itself is toxic, turning on an enzyme that chews up muscle cells. Once the leak starts, it's a vicious cycle. The calcium leak raises levels of damaging reactive oxygen species, which oxidize RyR1 and worsen the leak.The researchers made their discovery by studying the skeletal muscles of young and old mice. They also showed that 6-month-old mice carrying a mutation that made their RyR1 channels leaky showed the same muscular defects and weakness characteristic of older mice.When older mice were treated with a drug known as S107, the calcium leak in their muscles slowed and the animals voluntarily showed about a 50 percent increase in the amount of time spent wheel running. Now in clinical trials for patients with heart failure, the drug is known to work by restoring the connection between costabilin and RyR1.Despite considerable effort to understand and reverse age- related muscle wasting, there are no established treatments available. The new work suggests there may be hope in approaching the problem from a different angle."Most research has focused on making more muscle mass," Marks said. "What's different here is that we are focused not on muscle mass but on muscle function. More muscle doesn't help if it is not functional."

WELLINGTON, July 29 (Xinhua) -- Scientists from around the world will gather on the east coast of New Zealand next week to discuss proposals to study "silent" earthquakes by drilling into the seabed.Silent quakes, also known as slow slip events, occur on the boundaries of the earth's tectonic plates, where one plate dives under another in areas known as subduction zones, and are slower than normal quakes, taking weeks or months to occur rather than seconds, and are rarely felt on the surface.About 70 scientists from 10 countries will convene in the city of Gisborne, which lies near the site of a major fault line and where scientists first identified silent earthquakes in 2002.Slow-slip events were first discovered with the advent of new measurement technologies on the west coast of Canada about 15 years ago and have since been recorded at about a dozen locations around the world, including four sites around New Zealand, said a spokesperson for New Zealand's Institute of Geological and Nuclear Sciences (GNS Science).About eight slow-slip episodes have occurred under Gisborne since 2002 at roughly two-year intervals.Scientists have proposed numerous theories to explain the phenomenon, but testing the theories is difficult as silent quakes happen many kilometers below ground."The best way to understand the true cause of slow-slip events is to drill into and sample the area on the plate boundary fault where they are known to occur, and monitor a whole range of physical and chemical properties at the plate interface," said Laura Wallace, of GNS Science.

JIUQUAN, Gansu, Sept. 26 (Xinhua) -- Engineers are conducting the final preparations before launching China's first space laboratory module at the end of this week at a launch center in northwest China.The unmanned Tiangong-1 module was originally scheduled to be launched into low Earth orbit between Sept. 27 and 30. However, a weather forecast showing the arrival of a cold air mass at the Jiuquan Satellite Launch Center forced the launch to be rescheduled for Sept. 29 or 30, depending on weather and other factors."This is a significant test. We've never done such a thing before," said Lu Jinrong, the launch center's chief engineer.A full ground simulation was conducted on Sunday afternoon to ensure that the module and its Long March 2F carrier rocket are prepared for the actual launch.Cui Jijun, commander-in-chief of the launch site system and director of Jiuquan Satellite Launch Center, told Xinhua that they developed a new target spacecraft for the mission and made more than 170 technical improvements to the Long March 2F, China's manned orbital carrier rocket.Engineers have also made more than 100 updates at the launch site in order to make it compatible with the Tiangong-1, Cui added.The module will conduct docking experiments after entering orbit, which is the first step in China's space station program.Cui said the launch site has an updated computer center and command monitoring system and increased ability to adapt to changes in mission conditions, as well as the resources to handle both the launch and command duties. An integrated simulation training system for space launching has also been developed for the docking mission.The mission comes just one month after the Long March 2C rocket malfunctioned and failed to send an experimental satellite into orbit. The Tiangong-1 mission was subsequently rescheduled in order to allow engineers to sort out any problems that might occur during the launch.Cui said that engineers conducted a two-month comprehensive technical check on equipment at the launch site from March to May. The safety and reliability of all the instruments have been significantly improved."[The launch site] has the full conditions to conduct the Tiangong-1 mission," said Cui.The Tiangong-1 will remain in orbit for two years. During its mission, it will dock with China's Shenzhou-8, -9 and -10 spacecrafts.Unmanned docking procedures will be an essential step toward China achieving its goal of establishing a manned space station around 2020.

WUHAN, Aug. 6 (Xinhua) -- A Chinese man nearing 80 years old was recently diagnosed with HIV and doctors say he probably caught the virus through having "frequent unprotected sex."The case is the latest to support the opinions of experts who believe the virus is spreading fast among older Chinese men who have been largely neglected in the country's anti-AIDS campaigns.The latest diagnosed man, whose identity has been concealed for privacy reasons, was admitted to Zhongnan Hospital in central Chinese city of Wuhan with a lingering fever. He was later found to be HIV positive, doctors at the hospital said Friday.The man was widowed in his old age, has no record of blood transfusions, but had an "active unprotected sexual life," they said.Gao Shicheng, a HIV specialist in Zhongnan Hospital, said that HIV/AIDS has started to infect middle-aged and elderly Chinese men who have little or no AIDS prevention knowledge.Gao said this year alone he had diagnosed two senior men with HIV. Both contracted the virus through unprotected sex outside marriage.A recent survey conducted by the Chinese Center for Disease Control and Prevention (China CDC) shows that among the new HIV infections, the percentage of people aged 50 or above with it grew from 7.8 to 14.9 percent. Most of them were male and were found to have contracted the virus through sexual intercourse.Experts say the spread of HIV/AIDS has picked up among older Chinese men in recent years because China's senior citizens have become healthier, more open-minded about sex, and increasingly bored after retirement.They called for anti-AIDS campaigns, which usually target young people with a focus on gays, sex workers, and rural migrants, to also cover seniors in a bid to raise the awareness of HIV/AIDS prevention knowledge.China is fighting a hard battle to contain the spread of HIV/AIDS. According to a UNAIDS estimate, the country had about 740,000 people living with HIV by the end of 2009. Among them, 105,000 were estimated to have AIDS.By the end of August 2010, the cumulative total of reported HIV positives in China was 361,599, with 65,104 recorded deaths.Sex, other than blood transmission or mother-to-child transmission, has become the main channel for the spread of HIV in China.

SAN FRANCISCO, July 12 (Xinhua) -- Facebook and Time Warner announced on Tuesday that they are teaming up to launch a wide- ranging, major cross-platform partnership initiative to fight bullying.The multi-media campaign, named "Stop Bullying: Speak Up" after the original anti-bullying initiative by Time Warner's Cartoon Network, will integrate broadcast, print, online and social media to educate parents, teachers and youth about the actions that will help protect young people from the impact of bullying, the two said in a joint statement.As part of the initiative, Facebook is scheduled to launch an interactive application in the back-to-school season this fall, which will enable educators, parents, and kids to make a personal commitment to help stop bullying."We care deeply about the safety of our nation's children and are proud to be partnering with Time Warner to raise awareness of bullying," Sheryl Sandberg, Facebook's chief operating officer, said in the statement."We believe that by working together with parents and teachers, we can teach young people to speak up and stop bullying," she added.Time Warner is also planning to expand its multiplatform efforts to communicate the anti-bullying message to an broader audience.It said in October, three of its magazines -- People, Sports Illustrated and Time -- and their affiliated websites will feature editorial content that highlights the problem of bullying and innovative programs and measures being taken to combat it.In partnership with Facebook, CNN's Anderson Cooper will also host a new town hall, which is scheduled to air in October and will be dedicated to discussing bullying issues confronting kids today as well as discussions with experts to teach adults on coping with the bullying epidemic."I'm confident that through our multiplatform approach and combined resources we can inspire even more people to take action against bullying," said Jeff Bewkes, Time Warner's chairman and chief executive officer.

来源：资阳报