梅州结核性宫颈炎有何症状(梅州做流产哪家医院好) (今日更新中)

WASHINGTON, July 13 (Xinhua) -- Human neural stem cells are capable of helping people regain learning and memory abilities lost due to radiation treatment for brain tumors, a University of California, Irvine (UCI) study suggests.Research with rats found that stem cells transplanted two days after cranial irradiation restored cognitive function, as measured in one- and four-month assessments. In contrast, irradiated rats not treated with stem cells showed no cognitive improvement."Our findings provide solid evidence that such cells can be used to reverse radiation-induced damage of healthy tissue in the brain," said Charles Limoli, a UCI radiation oncology professor.Study results will appear Friday in Cancer Research, a journal of the American Association for Cancer Research.Radiotherapy for brain tumors is limited by how well the surrounding tissue tolerates it. Patients receiving radiation at effective levels suffer varying degrees of learning and memory loss that can adversely affect their quality of life."In almost every instance, people experience severe cognitive impairment that's progressive and debilitating," Limoli said. " Pediatric cancer patients can experience a drop of up to three IQ points per year."For the UCI study, multipotent human neural stem cells were transplanted into the brains of rats that had undergone radiation treatment. They migrated throughout the hippocampus -- a region known for the growth of new neurons -- and developed into brain cells.Researchers assessed the rats one month and four months after transplantation, noting enhanced learning and memory abilities at both intervals.Additionally, they found that transplanting as few as 100,000 human neural stem cells was sufficient to improve cognition after cranial irradiation. Of cells surviving the process, about 15 percent turned into new neurons, while another 45 percent became astrocytes and oligodendrocytes -- cells that support cerebral neurons.Most notably, Limoli said, he and his colleagues discovered that about 11 percent of the engrafted cells expressed a behaviorally induced marker of learning, indicating the functional integration of those cells into memory circuits in the hippocampus."This research suggests that stem cell therapies may one day be implemented in the clinic to provide relief to patients suffering from cognitive impairments incurred as a result of their cancer treatments," Limoli said.

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.

SAN FRANCISCO, Sept. 6 (Xinhua)-- Yahoo on Tuesday fired Chief Executive Officer Carol Bartz and replaced her temporarily with the company's chief financial officer."On behalf of the entire board, I want to thank Carol for her service to Yahoo during a critical time of transition in the company's history, and against a very challenging macro-economic backdrop," said Yahoo Chairman Roy Bostock in a news release.The Yahoo Board of Directors appointed CFO Timothy Morse as interim CEO who will manage the company's day-to-day operations until a permanent chief executive is chosen.Carol Bartz, chief executive of Internet company Yahoo Inc, is shown in this undated publicity photo released to Reuters January 13, 2009. Before Yahoo's formal announcement, several news organizations and tech blogs posted an email reportedly from Bartz sent from her iPad to all employees of the company."To all, I am very sad to tell you that I've just been fired over the phone by Yahoo's Chairman of the Board. It has been my pleasure to work with all of you and I wish you only the best going forward."Bartz, 63, took over the Yahoo CEO role from co-founder Jerry Young in January 2009, when the company was struggling to stay competitive and profitable in a market dominated by Google. However, Yahoo never reached the heights she had foreseen.In the most recent quarterly earnings report in June, Yahoo reported net revenue of 1.1 billion U.S. dollars, down 5 percent from last year.Morse, 42, was hired as executive vice president and CFO at Yahoo in July 2009. "It is an honor to be selected for this role," he said in a statement Tuesday.Yahoo said it is starting a search for a new permanent CEO and plans to hire a "nationally recognized executive search firm" to assist in the effort.

BEIJING, July 5 (Xinhuanet) -- Facebook CEO Mark Zuckerberg confirmed that he has signed up to Google+, the new social networking platform from Google, according to media reports Tuesday.Launched last month, Google+ is the Internet giant's latest foray into social networking.Zuckerberg confirmed that the profile with his name on Google+ belongs to him only, and said, "Why are people so surprised that I'd have a Google account?" Facebook CEO Mark Zuckerberg reacts after unveiling a new messaging system during a news conference in San Francisco, California November 15, 2010.In social networking field, it is rare for someone to join the rival's platform, therefore, Zuckerberg's move is considered strange.But interestingly, Zuckerberg has more followers than Google founders Larry Page and Sergey Brin, and even Vic Gundotra, the man behind Google+, with over 21,000 people.Besides Google+, Zuckerberg also has an account on Twitter, though it has not been updated for some time.

DUBLIN, June 27 (Xinhua) -- The Irish government is aiming to increase internet literacy among older people with the launch of a 1.6 million euro training program, according to a cabinet minister on Monday.The goal of the scheme is to provide basic internet skills to 30,000 elderly people across the country who are less likely engage with the internet themselves.The announcement was made by Irish communications minister Pat Rabbitte at a new computer training facility run by Age Action Ireland, an Irish charity which promotes positive aging and better policies and services for older people.The Irish minister detailed how the training program will help those involved."This scheme will enable thousands of people throughout Ireland, people otherwise likely to be left behind in the knowledge society, to acquire the basic practical know-how to improve their digital skills. In particular this will help older people, those with disabilities, the unemployed and other key target groups. They will learn to use the internet, emails and how to conduct simple on-line transactions," he said."Previous schemes show that learning such basic skills helps people in many ways, giving them new communication options, new opportunities to save money, as well as better access to a wide range of on-line services," he added."We have also seen how such new skills and the opportunities that result from them improve people's confidence and wellbeing. More widespread participation in the knowledge society is a win- win outcome with advantages for citizens, government and the wider economy."

来源：资阳报