郑州枕骨颈椎和椎动脉脊神经脑干模型(伊春喉软骨模型) (今日更新中)

BEIJING, Sept. 23 (Xinhua) -- A defunct U.S. satellite is expected to crash down to Earth Friday, with nobody knowing where or when exactly it will hit. This was avoidable, a Chinese expert said Thursday.Pang Zhihao, a researcher from the Chinese Research Institute of Space Technology, told Xinhua that the crash could have been avoided had the satellite been put into a higher orbit, or manipulated to drop in the South Pacific when it had abundant fuel. It would pose no threat to Earth if these measures had been taken.NASA's tumbling, 5,900 kg Upper Atmosphere Research Satellite, or UARS, is the first of such man-made space vehicles that have been launched into outer space according to the agency's Mission to Planet Earth. The mission was launched in the 1990s.The mission is designed to provide data for better understanding Earth's upper atmosphere and the effects of natural and human interactions on the atmosphere.The satellite was deactivated in 2005 as it ran out of fuel and was left orbiting Earth like a big piece of space junk.There are other cases of defunct satellites. The European Space Agency said earlier its observation satellite ERS-2 has run out of fuel and is deorbiting. It would therefore also crash sooner or later.Pang said all countries which are operating space vehicles should take care of their own spacecrafts so that they won't pose any danger.The expert also said that the public need not worry too much.Pang said most spacecrafts will be incinerated upon re-entering Earth's atmosphere, and the debris will mostly likely fall into the ocean or hit an uninhabited area. In addition, a debris tracker is able to give a comparatively accurate prediction where the craft will fall about two hours before it hits Earth, giving residents, if there are any, time to evacuate.He added that there are several ways to minimize the threat of decommissioned spacecrafts, like putting them into higher orbits and crashing them into designated waters.Scientific progress would possibly bring about more ways of dealing with tumbling satellites. Scientists have already been trying to build spacecrafts with degradable materials so that they can self-destruct when re-entering Earth's atmosphere.

BEIJING, Sept. 2 (Xinhuanet) -- Firefighters who worked in the wreckage of the World Trade Center in 2001 were 19 percent more likely to develop cancer than those who were not there, according to a study.The study, published Thursday in the British medical journal The Lancet, surveyed cancer occurrence in nearly 10,000 male firefighters in the seven years after Sept. 11, 2001. (There were too few women to create a meaningful sample size.)The 9/11 attacks occurred on Tuesday, Sept. 11, 2001. As a result, the World Trade Center collapsed, and nearly 3,000 Americans killed. Among the 2,753 victims killed in the World Trade Center were 343 firefighters.There were 263 cancer cases in the exposed population, showing a cancer rate 19 percent higher than that of the group not exposed.The study indicated that cancers like melanoma, non-Hodgkin’s lymphoma, thyroid and prostate cancer occurred more frequently among exposed firefighters than in the general population. But occurrences of lung cancer did not increase.The findings “provide information that there may be a significant cancer risk for these people”, said Dr. James Melius, the administrator of the New York State Laborers’ Health and Safety Trust Fund and one of the peer reviewers of the study.But the results were far from conclusive. “This is not an epidemic,” said Dr. David J. Prezant, a lead researcher and the chief medical officer for the New York Fire Department.

WASHINGTON, Sept. 13 (Xinhua) -- The U.S. Department of Health and Human Services (HHS), with several partners, on Tuesday launched Million Hearts, an initiative that aims to prevent one million heart attacks and strokes over the next five years.The program will focus on helping Americans make healthy choices, such as preventing tobacco use and lowering consumption of salt and trans fats, and increasing use of treatments like aspirin and blood pressure and cholesterol-lowering medications.The HHS hopes that by 2017, 65 percent of high-risk patients will be taking aspirin and have their blood pressure and cholesterol under control. Currently, only 47 percent of high-risk patients take aspirin, and only 33 percent have their cholesterol and 46 percent their blood pressure under control.They also aim to cut smoking to 17 percent of Americans from 19 percent by 2017, and seek a 20 percent drop in sodium intake and a 50 percent drop in trans fat consumption."Heart disease causes one of every three American deaths and constitutes 17-percent of overall national health spending," said HHS Secretary Kathleen Sebelius in a statement. "By enlisting partners from across the health sector, Million Hearts will create a national focus on combating heart disease."

BEIJING, Sept. 20 (Xinhua) -- Floods and landslides triggered by recent heavy rains in eight of China's provincial-level regions have left 70 people dead and 32 others missing this month.Heavy downpours, floods and other related disasters have affected Sichuan, Shaanxi, Henan, Chongqing, Hubei, Shandong, Shanxi and Gansu, the National Disaster Reduction Commission said in a statement released on Tuesday.As of Tuesday, these disasters have affected 21.56 million people and caused an estimated 26.09 billion yuan (4.08 billion U.S. dollars) in direct economic losses, the statement said.

SAN FRANCISCO, Sept. 27 (Xinhua) -- Apple on Tuesday announced an invitation-only special event featuring iPhone on Oct. 4, 2011.With a simple headline reading "Let's talk iPhone," the invitation said that there will be an "executive presentation at 10 a.m.." This could be the first big product introduction by the newly installed Chief Executive Officer Tim Cook after he took over the reins of Apple from Steve Jobs in August.The event, which will be held at Apple campus in Cupertino, California, has long been reported to be the introduction of iPhone 5, the next generation iPhone.According to U.S. media reports, the iPhone 5 is expected to have revamped hardware design with a larger screen, a higher resolution camera and a faster dual-core A5 chip on which the iPad 2 runs. Apple is also reported to release a low-cost and contract- free iPhone model bundled with its cloud computing service iCloud.

来源：资阳报