贵阳脑干矢状切面模型(安徽胎儿妊娠发育过程模型（10部件）) (今日更新中)

WASHINGTON, Aug. 4 (Xinhua) -- Researchers have found a way to turn mouse embryonic stem cells into sperm and this finding opens up new avenues for infertility research and treatment, according to a study published Thursday in the online edition of journal Cell,A Kyoto University team coaxed mouse embryonic stem cells into sperm precursors, called primordial germ cells (PGCs), and shown that these cells can give rise to healthy sperm. The researchers say that such in vitro reconstitution of germ cell development represents one of the most fundamental challenges in biology.When transplanted into mice that were unable to produce sperm normally, the stem cell derived PGCs produced normal-looking sperm, which were then used to successfully fertilize eggs. These fertilized eggs, when transplanted into a recipient mother, produced healthy offspring that grew into fertile male and female adult mice. The same procedure could produce fertile offspring from induced pluripotent stem cells that are often derived from adult skin cells."Continued investigations aimed at in vitro reconstitution of germ cell development, including the induction of female primordial germ cell-like cells and their descendants, will be crucial for a more comprehensive understanding of germ cell biology in general, as well as for the advancement of reproductive technology and medicine," the researchers wrote.

SAN FRANCISCO, Sept. 9 (Xinhua) -- AOL's chief executive officer (CEO) Tim Armstrong has reached out to Yahoo for talks of a merger of the two companies, U.S. media reported on Friday.Armstrong is discussing options for a combination aimed at strengthening the two Internet companies, Bloomberg quoted two people who are familiar with the matter as saying.The report said that the AOL CEO had been interested in a merger with Yahoo last year but was rejected while Carol Bartz served as Yahoo CEO, who was ousted by Yahoo's board on Tuesday.Reconsidering the option after Bartz's departure, Armstrong has talked with private equity firms and investment bankers from Allen & Co. working with Yahoo.Under one scenario being considered, Yahoo would acquire AOL and Armstrong would become CEO of the combined company, said the source.Both Yahoo and AOL are suffering from declining revenues, struggling to compete against companies like Google and Facebook. Some analysts said that the merger could not provide a long-term solution to the problems the two companies face after they failed to keep up with Internet trends.

TOKYO, Sept. 23 (Xinhua) -- Japan's H-2A rocket carrying a new information gathering satellite was launched at the Tanegashima Space Center in Kagoshima Prefecture on Friday, local media reported.Japan has already introduced three information-gathering satellites in the wake of a missile launch by Democratic People's Republic of Korea, and the latest one will replace the No. 2 satellite which has passed its use-by date, Kydo News said.Japan's H-2A rocket lifts off from the launchiung pad at the Tanegashima space centre in Kagoshima prefecture, Japan's southern island of Kyushu on September 23, 2011. Japan launched a new spy satellite into orbit September 23, officials saidThe development cost of the fourth satellite has reached 35.9 billion yen and its launch expenses have come to 10.4 billion yen, according to the government.The Japan Aerospace Exploration Agency and Mitsubishi Heavy Industries Ltd. were forced to put off the launch three times during the past four weeks due to the approach of a powerful typhoon and discovery of a system glitch. The rocket was initially scheduled to be sent into orbit on Aug. 28.

SYDNEY, July 15 (Xinhua) -- The world's first drug to increase life expectancy of people with advanced melanoma has been approved for use in Australia, local media reported on Friday.The breakthrough drug Yervoy got approval from the Therapeutics Good Association (TGA) on Friday amid hopes it could add two years to the life of people with the most lethal form of skin cancer but for whom other treatments have failed, the Australian Associated Press (AAP) said.Clearance for the drug's use in Australia follows similar approvals by the U.S. health regulator in March.Yervoy works by attacking and destroying cancer cells.Patients are hooked up to an intravenous drip once every three weeks for a total of four doses.Professor Peter Hersey, consultant immunologist to the Melanoma Institute Australia, said no other drug had improved survival rates like Yervoy."Not all patients respond to it but those who do have a good chance of living longer than they would have otherwise," Hersey told AAP.While it may improve survival rates, Yervoy can produce side effects from diarrhea and vomiting to serious blood infections and kidney failure.The average survival time for people with advanced melanoma is just six months.A global study of 676 people with melanoma found that 45 percent of patients given Yervoy were still alive after one year, according to AAP.More than 20 percent lived at least two years, with a small number managing to survive for six years.A separate study, published in June, which showed similarly improved survival rates for patients with newly diagnosed advanced melanoma, has raised hopes that Yervoy could be made more widely available.Melanoma is the fourth most common cancer in Australia, with 10, 300 people diagnosed each year.

NEW YORK, July 15 (Xinhua) -- A Gallup survey released on Friday found a total of 59 percent of Americans support a ban on smoking in all public places.The July 7-10 survey among 1,016 national adults showed a change in the public's attitude toward public smoking ban. In 2001, when Gallup first asked about a ban on public smoking, 39 percent were in favor, an attitude that stayed roughly the same through 2007.At the same time, the poll also found that fewer than two in 10 people supported the idea of making smoking totally illegal.According to the American Lung Association, 27 states plus the District of Columbia have passed comprehensive smoke-free laws. A New York City law bans smoking in virtually all public places, including outdoor plazas and beaches.

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