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WASHINGTON, Oct. 13 (Xinhua) -- In a trial that included about 35,000 men, those who were randomized to receive daily supplementation with vitamin E had a significantly increased risk of prostate cancer, according to a study published this week in the Journal of the American Medical Association.The study followed more than 35,533 men 50 or older at 427 sites in the United States, Canada and Puerto Rico. The men were divided into four groups who took daily doses of 400 international units of Vitamin E and 200 micrograms of selenium; Vitamin E and a placebo that looked like selenium; selenium and a placebo that looked like Vitamin E; or two placebos. The recommended daily intake of Vitamin E is about 22.4 international units.The researchers from the Cleveland Clinic found that the rate of prostate cancer detection was greater in all treatment groups when compared with placebo but was statistically significant only in the vitamin E alone group -- a 17 percent increased rate of prostate cancer detection. The difference in rates of prostate cancer between vitamin E and placebo became apparent during the participants' third year in the trial. The elevated risk estimate for vitamin E was consistent across both low- and high-grade disease."The observed 17 percent increase in prostate cancer incidence demonstrates the potential for seemingly innocuous yet biologically active substances such as vitamins to cause harm. The lack of benefit from dietary supplementation with vitamin E or other agents with respect to preventing common health conditions and cancers or improving overall survival, and their potential harm, underscore the need for consumers to be skeptical of health claims for unregulated over-the-counter products in the absence of strong evidence of benefit demonstrated in clinical trials," the researchers said.

SAN FRANCISCO, Dec. 8 (Xinhua) -- Twitter on Thursday started to roll out a major redesign of its interface in hopes of simplifying users' experience, as well as new brand pages to strengthen its relationship with advertisers.During a press conference at its new headquarters in San Francisco, Twitter Chief Executive Officer Dick Costolo and co- founder Jack Dorsey unveiled a whole new look of the social networking and microblogging service.According to an introduction video, the new homepage features profile on the left and the timeline on the right, which are flipped from the current positions and take less space than they used to.Three new buttons were also introduced as "Home," "Connect" and "Discover." "Connect" shows users who has mentioned them and suggests some accounts they might want to follow. "When you use Discover, you'll see results reflecting your interests -- based on your current location, what you follow and what's happening in the world," said Twitter.The overhauled interface is only available to a small group of users at first and will be rolled out to all users over the coming months. It will also remain consistent across Twitter's official mobile apps. Twitter has launched a page fly.twitter.com to explain all the changes.Along with the introduction of the redesign, Twitter also announced new brand pages on its platform. A total of 21 brand partners will be included in the initial launch, such as American Express, Best Buy, Bing, Coca-Cola, HP, Disney and Nike.Analysts said Twitter has ambitions to compete with similar brand pages from Facebook and Google+. According to eMarketer, Twitter's global advertising revenue is expected to reach 139.5 million U.S. dollars this year and approach 400 million dollars in 2013.

WASHINGTON, Dec. 20 (Xinhua) -- NASA's Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system, the U.S. space agency announce Tuesday.The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet's surface, but they are the smallest exoplanets ever confirmed around a star like our sun, according to NASA.The discovery marks the next important milestone in the ultimate search for planets like Earth. The new planets are thought to be rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth. Kepler-20f is slightly larger than Earth, measuring 1.03 times its radius. Both planets reside in a five-planet system called Kepler-20, approximately 1, 000 light-years away in the constellation Lyra.Kepler-20e orbits its parent star every 6.1 days and Kepler-20f every 19.6 days. These short orbital periods mean very hot, inhospitable worlds. Kepler-20f, at 800 degrees Fahrenheit, is similar to an average day on the planet Mercury. The surface temperature of Kepler-20e, at more than 1,400 degrees Fahrenheit, would melt glass."The primary goal of the Kepler mission is to find Earth-sized planets in the habitable zone," said Francois Fressin of the Harvard-Smithsonian Center for Astrophysics, lead author of a new study published in the journal Nature. "This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them."The Kepler-20 system includes three other planets that are larger than Earth but smaller than Neptune. Kepler-20b, the closest planet, Kepler-20c, the third planet, and Kepler-20d, the fifth planet, orbit their star every 3.7, 10.9 and 77.6 days. All five planets have orbits lying roughly within Mercury's orbit in our solar system. The host star belongs to the same G-type class as our sun, although it is slightly smaller and cooler.

ADDIS ABABA, Dec. 2 (Xinhua) -- Xie Xiaoyan, the newly appointed Chinese ambassador to Ethiopia and the African Union (AU) on Friday presented his letter of credence to Jean Ping, chairperson of the AU Commission (AUC) at his office in Addis Ababa, Ethiopia.After presenting the credential letter to Ping at the AU headquarters, Ambassador Xie held talks with the AUC chief on the relations and cooperation between China and the union of 54 member countries.The Chinese government has constructed a state-of-the-art office complex and conference hall for the AU with an outlay of around 125 million U.S. dollars, a project that demonstrates the friendship between China and Africa.

YICHANG, Oct. 30 (Xinhua) -- China's Three Gorges Dam on Sunday reached its designed highest mark, the second time for the world's largest water control and hydropower project to run at full capacity.The water level hit 175 meters at 5 p.m. after storing water for nearly two months from the water level of 152 meters, said an official with the China Three Gorges Project Corporation (CTGPC), the developer of the project.A dozen hydropower turbo-generator units started operation on Sunday, generating power capacity of 8.2 million kw, said the official.The dam in central China's Hubei Province completed its first full-capacity test last October.Operating at full capacity should give full play to the dam's functions of generating hydroelectric power, delivering water to the lower reaches to alleviate spring droughts, and containing water from summer flooding, as required by the State Flood Control and Drought Relief Headquarters.The Three Gorges Project was launched in 1993 with a budget equivalent to 22.5 billion U.S. dollars.So far, monitoring shows the dam is operating smoothly.