尿结石多大才需要碎石重庆(重庆胆囊疼痛的症状) (今日更新中)

BEIJING, Sept. 4 (Xinhua) -- Officials and delegations from China and African countries have gathered at a seminar being held in Beijing to discuss rural development and economic growth.The seven-day seminar kicked off on Sunday, attracting representatives from China and 11 African countries to exchange views and experiences related to the seminar's theme of "agriculture and rural development."Justin Lin Yifu, chief economist and senior vice president of the World Bank, said at the seminar's opening ceremony that African countries should take cues from China's experience in creating a series of policies to bolster agricultural and rural development, as these policies have also facilitated the country's economic growth.Hu Jinglin, assistant to China's Minister of Finance, said improved agricultural cooperation between China and Africa will help enhance global grain security.China has worked on 142 cooperative agricultural projects with 14 African countries to date. In addition, it has sent 104 agricultural experts to 33 African countries to train more than 4,200 local agricultural technicians.

BEIJING, Aug. 22 (Xinhuanet) -- Researchers have discovered how a human egg captures an incoming sperm for fertilization, paving the way to help couples suffering from infertility, according to media reports on Monday.An international team of researchers found that a sugar chain known as the sialyl-lewis-x sequence (SLeX) makes the outer coat of the egg “sticky,” which has proven to be helpful in binding the egg and the sperm.As a result, this observation has filled in a huge gap in the understanding of fertility and provides hope for ultimately helping couples who currently cannot conceive.Scientists and doctors know that a sperm identifies an egg when proteins on the head of the sperm match and bind to a series of specific sugars in the egg’s outer coating. With a successful match of proteins, the outside surfaces of the sperm and egg then bind together before merging, which is then followed by delivery of sperm’s DNA into egg.To identify this molecules, the researchers used ultra-sensitive mass-spectrometric imaging technology to observe and identify which molecules are most likely to be key in the binding process.They experimented with a range of synthesised sugars in the laboratory and found that it is SLeX that specifically binds sperm to an egg.According to the World Health Organisation, infertility affects about 15 percent of reproductive-aged couples around the world and almost one in every seven couples in Britain has problems conceiving a child for various reasons.

LOS ANGELES, June 7 (Xinhua) -- Salmonella, not E. coli, poses the greatest health threat to Americans, the U.S. Centers for Disease Control and Prevention (CDC) announced on Tuesday.Salmonella infections have risen 10 percent over the past 15 years, while several types of foodborne illness have been falling, the agency said in a report.Infections from Shiga toxin-producing E. coli O157 (the strain of most concern in the United States) have dropped almost in half and the rates of six other foodborne infections have been cut 23 percent, the CDC said.The agency issued the report as a deadly new strain of E.coli is spreading in several European countries."There are about 50 million people each year who become sick from food in the U.S.. That's about one in six Americans," CDC director Dr. Thomas R. Frieden said.The CDC attributed the reduction in infections from E. coli O157 to better detection and investigation of outbreaks, cleaner slaughterhouse methods, better testing of ground beef for E. coli, improved inspections of ground beef processing plants, regulations prohibiting E. coli O157 in ground beef and increased awareness of the importance of properly cooking beef.Other foodborne illnesses that fell in incidence over the same time period include those caused by the campylobacter, listeria, vibrio and yersinia pathogens.To reduce their risk of foodborne illness, people should assume that raw chicken and other meat have bacteria that can make you sick, the CDC said.In the kitchen, raw meats should not allow to contaminate counter tops or cutting boards and should be kept away from other foods, such as fruits and vegetables, the CDC advised.The agency also called on people to thoroughly cook meat, poultry, eggs and shellfish, while refraining from consuming unpasteurized milk, juice or soft cheese.

BEIJING, July 3 (Xinhuanet) -- The Atlantis mission to be launched by NASA on July 8 will not be an end to the space age, as some media suggest.Although it is the final mission of the space shuttle, it will open up "the next chapter" in the United States' space exploration, NASA's administrator Charles Bolden Jr said at the National Press Club in Washington on Friday."When I hear people say - or listen to media reports - that the final shuttle flight marks the end of US human space flight, I have to say . . . these folks must be living on another planet," he said."As a former astronaut and the current NASA administrator, I'm here to tell you that American leadership in space will continue for at least the next half-century because we have laid the foundation for success - and for NASA, failure is not an option," he said.NASA administrator Charles Bolden Jr drew a lot of media attention during his speech at the National Press Club in Washington DC.One of the foundations is the "unprecedented" research capabilities the International Space Station (ISS) now possesses, largely thanks to the space shuttle missions.Although some media imply that "the game will be up" once the ISS is out of orbit in 2020, he said the splendid research results and rich knowledge astronauts and scientists have accumulated through more than 1,200 experiments since 1998 have laid out "a stepping-stone to the rest of the solar system and the tip of what comes next".As NASA turns a new page, it will "focus on deep space exploration", while leaving US private companies to operate low Earth orbit transportation systems for tourism and business, he said.NASA will develop "a deep space crew vehicle and an evolvable heavy-lift rocket," he said. The moon, asteroids and Mars will be the next destinations for humans to live and work, he said."We will maintain and grow US leadership in space and derive all the benefits that flow from it. Tomorrow's space program is taking shape right now," he said.

MOSCOW, June 15 (Xinhua) -- Russia's Mission Control announced on Wednesday it had raised the International Space Station (ISS) by 10.2 km to 374.7 km with the help of the Europe's ATV-2 Johannes Kepler.The Mission Control conducted the correction to the ISS at 19: 55 Moscow time (1555 GMT) by the boosters of the ATV-2 Johannes Kepler. The correction had lasted for some 40 minutes.According to the Mission Control, the correction was made in line with the ISS's ballistic flight program.On June 12, the Europe's second Automated Transfer Vehicle (ATV) Johannes Kepler has conducted two similar operations, raising the ISS orbit by 19.2 km to 364.6 km.Corrections to the space station's orbit are conducted periodically before launches of Russian cargo ships and U.S. shuttles to compensate for the Earth's gravity and to safeguard successful dockings.According to the Mission Control, the ATV-2 Johannes Kepler is scheduled to undock from the ISS on June 21.

来源：资阳报