安康白带呈褐色是什么原因引起的(安康月经后几天会受孕) (今日更新中)

LOS ANGELES, July 18 (Xinhua) -- At least 70 genetic mutations may be involved in the formation of colon cancer, far more than scientists previously thought, a new study suggests.The study by researchers at University of Texas (UT) Southwestern Medical Center contradicts previous thinking that only a few mutated genes may play a role in the development of colon cancer."The ways we've been treating patients up to now is to just go after one target when we should be going after three to four different pathways simultaneously," said Dr. Jerry W. Shay, vice chairman and professor of cell biology at UT Southwestern.The new study identified 65 candidate genes and at least five passenger genes whose mutations play significant roles in cancer development. Inactivating the function of any of these tumor- suppressing genes led to a key step in cancer development called anchorage-independent growth, meaning cells piled up on top of each other rather than aligning neatly.According to previous studies, there were 151 candidate genes and that mutations in just eight to 15 of them would lead to cancer. There were 700 other genes classified as passenger genes whose mutations were incidental to cancer growth.Current cancer treatments target just one or two known cancer- driver genes. While patients may get transient tumor burden reduction, almost universally tumor growth returns."Those numbers are dead wrong," Dr. Shay said, suggesting a new approach to colon cancer treatments targeting multiple genes and pathways simultaneously.The next step is further research to classify more accurately which genes drive cancer and which are merely passengers, the researchers said.Study findings were published in the July 2011 Cancer Research (Priority Reports).

BEIJING, Aug. 23 (Xinhuanet) -- More than 90 percent of U.S. heart attack patients who need the lifesaving procedure receive it within just 90 minutes of being admitted to the hospital, according to a study released Monday in the journal Circulation.The study on the American Heart Association's journal shows that in 2010, 91 percent of heart attack patients who needed angioplasty were treated within the 90-minute window. While in 2005, 44% were.Researchers analyzed data on more than 300,000 such patients who underwent emergency angioplasty between January of 2005 and October of 2010.The improvement is the result of a nationwide effort between federal agencies, health care organizations and health care providers to improve heart attack care and outcome, said study author Dr. Harlan M. Krumholz, a professor of medicine and epidemiology and public health at Yale University School of Medicine, according to U.S. News reports.

BEIJING, Sept. 27 (Xinhuanet) -- Last-minute preparations for the launch of the Tiangong-1 spacecraft began at the Jiuquan Satellite Launch Center on Monday, meaning the vehicle can soon embark on a mission that will eventually have it dock with a spaceship, according to the center.That feat, if carried out successfully, will mark the completion of China's first rendezvous and docking mission.At the launch site on Monday afternoon, crews were putting in place pipes and cables that will be used to inject fuel into the rocket that will carry Tiangong-1 into outer space.Without complications from the weather or other causes, the Long March II-F rocket will lift off from the launch center on Thursday or Friday, taking the Tiangong-1 with it, according to the Xinhua News Agency.Despite the preparations, space experts said carrying out the plan still comes with many risks. They explained that the spacecraft and much of the other equipment being used is new and has not been tried on an actual mission."Tiangong-1 is a brand new spacecraft designed by China and is bigger and heavier than the Shenzhou spaceships China had developed as a means of transporting astronauts from the Earth to space," said Yang Hong, chief designer of Tiangong-1.In a vertical position, the Tiangong-1 looks like a cigar standing 10.4 meter tall, a height equal to that of a three-story building. It weighs 8.5 tons and has a maximum diameter of 3.35 meters, a dimension shared by its launch vehicle, he said.In comparison, the Shenzhou spaceship stands shorter, at nearly 9 meters, is slimmer, having a diameter of less than 3 meters, and weighs less.In another difference, the Tiangong-1 is composed of two modules rather than the three that had made up the Shenzhou spaceship. Of the Tiangong-1's two primary components, one is an experimental module that contains a place that astronauts can live and work in on future missions. It is also equipped with a docking port.The other chief component, a resource module, will provide the craft with power.Astronauts on Tiangong-1 will have 15 cubic meters of space to move in, "much more than they had in the Shenzhou spaceship", Yang said.Inside the spacecraft are two sleeping sections with adjustable lighting systems, exercise equipment, entertainment systems and visual communication devices, he said.Hou Xiangyang, who helped design Tiangong-1, said: "The sleeping section is big enough for a 1.8-meter-tall man to sleep in. An astronaut can adjust the light as he likes."In space, Tiangong-1 will fly in a horizontal position. A paint scheme inside will help the astronauts aboard maintain their sense of direction; the module's inner walls will be in two colors, one commonly associated with the sky and one with the ground."This will help astronauts avoid feeling as if they are standing upside down in the microgravity environment," he said.Yang said the Tiangong-1 spacecraft is expected to stay in orbit for two years and rendezvous and dock with three different spaceships. Beyond the Shenzhou VIII, ships named Shenzhou IX and Shenzhou X will embark on similar missions; at least one of the two is to be manned.Before astronauts climb on board Tiangong-1, the conditions inside its experimental module will be adjusted to ensure they can live in an environment that contains enough oxygen, moisture and heat to be safe.Tiangong-1 was originally scheduled to be launched into a low orbit around the Earth between Sept 27 and 30. The earlier days were removed as possible launch dates, though, after forecasters predicted a cold air mass would move into the area containing the Jiuquan Satellite Launch Center.To ensure the spacecraft and Long March II-F carrier rocket are ready for launch, a full ground simulation was conducted on Sunday afternoon.

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, Aug. 10 (Xinhuanet) -- A new technology can tell pregnant women whether they're having a boy or girl as early as seven weeks into a pregnancy -- months earlier than usual, according to media reports Wednesday.The technology works by detecting "cell-free fetal DNA," or DNA from the fetus, which floats freely in a pregnant woman's blood, said author Diana Bianchi of the Tufts University School of Medicine in Boston. Her analysis of 57 studies from peer-reviewed medical journals showed that these blood tests, common in Europe but not in the U.S. can reveal a fetus' sex only a week or two after a pregnant woman misses her period. Women usually learn the fetus' sex through an ultrasound at 18 to 20 weeks.The technology will help families worried by having a child with rare genetic disorders that typically affect only boys, such as hemophilia or a type of muscular dystrophy, said Joseph Biggio, director of the Trimester Genetics Screening Clinic at the University of Alabama-Birmingham.If they're having a girl, however, they can stop worrying, he added, and avoid further invasive tests, which can provide a definitive answer about genetic disorders, but also increase the risk of miscarriage. Women who learn they're carrying boys would still need a definitive test, such as an amniocentesis, to find out if their fetus is affected.

来源：资阳报