中山痔疮引起的大便出血(中山哺乳期便秘严重怎么办) (今日更新中)

LOS ANGELES, July 22 (Xinhua) -- Two teams of astronomers have discovered the largest and farthest reservoir of water ever detected in the universe, NASA's Jet Propulsion Laboratory (JPL) said on Friday.The water, equivalent to 140 trillion times all the water in the world's ocean, surrounds a huge, feeding black hole, called a quasar, more than 12 billion light-years away, according to JPL in Pasadena, California."The environment around this quasar is very unique in that it's producing this huge mass of water," said Matt Bradford, a scientist at JPL. "It's another demonstration that water is pervasive throughout the universe, even at the very earliest times. "This artist's concept illustrates a quasar, or feeding black hole, similar to APM 08279+5255, where astronomers discovered huge amounts of water vapor. Gas and dust likely form a torus around the central black hole, with clouds of charged gas above and below. X-rays emerge from the very central region, while thermal infrared radiation is emitted by dust throughout most of the torus. While this figure shows the quasar's torus approximately edge-on, the torus around APM 08279+5255 is likely positioned face-on from our point of view.A quasar is powered by an enormous black hole that steadily consumes a surrounding disk of gas and dust. As it eats, the quasar spews out huge amounts of energy. Both groups of astronomers studied a particular quasar called APM 08279+5255, which harbors a black hole 20 billion times more massive than the sun and produces as much energy as a thousand trillion suns.Astronomers expected water vapor to be present even in the early, distant universe, but had not detected it this far away before. There's water vapor in the Milky Way, although the total amount is 4,000 times less than in the quasar, because most of the Milky Way's water is frozen in ice. Water vapor is an important trace gas that reveals the nature of the quasar. In this particular quasar, the water vapor is distributed around the black hole in a gaseous region spanning hundreds of light-years in size (a light-year is about six trillion miles).Its presence indicates that the quasar is bathing the gas in X- rays and infrared radiation, and that the gas is unusually warm and dense by astronomical standards, JPL said.Although the gas is at a chilly minus 63 degrees Fahrenheit ( minus 53 degrees Celsius) and is 300 trillion times less dense than Earth's atmosphere, it's still five times hotter and 10 to 100 times denser than what's typical in galaxies like the Milky Way, said JPL.Measurements of the water vapor and of other molecules, such as carbon monoxide, suggest there is enough gas to feed the black hole until it grows to about six times its size, JPL said.Whether this will happen is not clear, the astronomers say, since some of the gas may end up condensing into stars or might be ejected from the quasar.Bradford's team made their observations starting in 2008, using an instrument called "Z-Spec" at the California Institute of Technology's (Caltech's) Submillimeter Observatory, a 33-foot (10- meter) telescope near the summit of Mauna Kea in Hawaii. Follow-up observations were made with the Combined Array for Research in Millimeter-Wave Astronomy (CARMA), an array of radio dishes in the Inyo Mountains of Southern California.The second group, led by Dariusz Lis, senior research associate in physics at Caltech and deputy director of the Caltech Submillimeter Observatory, used the Plateau de Bure Interferometer in the French Alps to find water. In 2010, Lis's team serendipitously detected water in APM 8279+5255, observing one spectral signature.Bradford's team was able to get more information about the water, including its enormous mass, because they detected several spectral signatures of the water, according to JPL.

BEIJING, July 11 (Xinhuanet) -- Gay and bisexual men account for around one in every three new cases of HIV in China, according to the latest official statistics released by the Ministry of Health.About 5 percent of the group - officially termed men who have sex with men, or MSM - are living with the virus, which is a rate that is 88 times higher than the national HIV prevalence rate of 0.057 percent.The problem is particularly acute in large urban centers, with the prevalence rate in some southwestern cities reaching almost 20 percent.However, the statistics also show that less than half of all gay and bisexual men have access to HIV screening, while about 15 percent of those who are infected are not receiving treatment."Cities are at the heart of China's development and progress and must remain at the forefront of its HIV response," said Michel Sidibe, executive director of the Joint United Nations Programme on HIV/AIDS (UNAIDS), during a workshop about the HIV impact on MSM on Saturday in Chengdu, capital of Southwest China's Sichuan province."Through bold action cities can lead the way to achieving the UNAIDS vision of zero new HIV infections, zero discrimination and zero AIDS-related deaths," he said, according to a UNAIDS news release. "We hope that over the next year, many more Chinese cities will implement MSM strategies."Almost 10 percent of gay and bisexual men in Chengdu are HIV-positive, according to Yang Xiaoguang, director of the city's health bureau. He agreed with Sidibe that cities have a crucial role to play in AIDS prevention and added: "By working to build a strong, multi-sector response in Chengdu, with meaningful community participation, we can scale-up coverage of prevention, treatment and care services among MSM and halt the spread of HIV."During the workshop, senior Chinese health officials, representatives from civil societies and other delegates discussed a new five-year strategy that increases coverage of HIV prevention and treatment for the MSM population and promotes the participation of community organizations.Government estimates put China's population of gay men at between 5 and 10 million, although Zhang Beichuan, a leading expert on HIV at Qingdao University, puts the number closer to 30 million.Tong Ge, coordinator of China's MSM Health Forum, noted the importance of ensuring strong cooperation between the government and society."By building on the experiences of cities like Chengdu, which already have well developed AIDS responses, we can help promote multi-sector collaboration on an equal, orderly basis and strengthen the response to HIV nationwide," he said. "The next step will be to implement similar strategies in other cities nationwide."Chengdu's new strategy underscores the critical role community organizations can play in reaching MSM and other populations at a higher risk of infection, experts at the workshop said.In 2009, China had an estimated 740,000 people living with HIV/AIDS, according to UNAIDS statistics.

WASHINGTON, July 5 (Xinhua) -- Adhering to a healthy lifestyle, including not smoking, exercising regularly, having a low body weight and eating a healthy diet, appears to lower the risk of sudden cardiac death (SCD) in women, according to a study to be published Wednesday in the Journal of the American Medical Association."Sudden cardiac death (defined as death occurring within one hour after symptom onset without evidence of circulatory collapse) accounts for more than half of all cardiac deaths, with an incidence of approximately 250,000 to 310,000 cases annually in the United States," the authors write as background information in the study.Using data collected as part of the Nurses' Health Study, Stephanie Chiuve, of Brigham and Women's Hospital and Harvard Medical School, and colleagues examined the association between a healthy lifestyle and risk of SCD.A total of 81,722 women who participated in the Nurses' Health Study from June 1984 to June 2010 were included in the new study, and lifestyle factors were assessed via questionnaires every two to four years. A low-risk lifestyle was defined as not smoking, having a body mass index (BMI) of less than 25, exercise duration of 30 minutes/day or longer, and consuming a diet closely related to a Mediterranean-style diet (emphasizes high intake of vegetables, fruits, nuts, legumes, whole grains and fish, with moderate alcohol intake).During the 26 years of follow-up, there were 321 cases of SCD among women (average age 72 years at the time of the SCD event) in the study. All four low-risk factors were significantly and independently associated with a lower risk of SCD. Not smoking, exercising and eating a healthy diet each were inversely associated with risk of SCD. BMI also was associated with the risk of SCD, with women having a BMI between 21 and 24.9 at lowest risk.Women at low risk for all four lifestyle factors had a 92 percent lower risk of SCD when compared with women at low risk for none of the four lifestyle factors."In this cohort of female nurses, adherence to an overall healthy lifestyle was associated with a lower risk of SCD and may be an effective strategy for the prevention of SCD," the authors write.

BEIJING, July 22 (Xinhuanet) -- Regulation is needed to govern rapidly expanding research in animals containing human tissue or genes, according to the Britain's Academy of Medical Sciences.Using animals with limited humanized traits is not new. Genetically engineered mice containing human DNA are already a mainstay of research into new drugs for diseases like cancer.For instance, Chinese scientists have already introduced human stem cells into goat fetuses and U.S. researchers have studied the idea of creating a mouse with human brain cells.But Martin Bobrow, a professor of medical genetics at the University of Cambridge, who led the Academy's working group, said there were three areas of particular concern."Where people begin to worry is when you get to the brain, to the germ cells, and to the sort of central features that help us recognize what is a person, like skin texture, facial shape and speech," he said.His report recommends that government should put in place a national expert body, working within the existing system for regulating animal research, to oversee such sensitive areas.British ministers said they welcomed the report and would consider its recommendations carefully.

来源：资阳报