中山治痔疮哪个医院比较好(中山每次大便是有血是怎么回事) (今日更新中)

WASHINGTON, Aug. 17 (Xinhua) -- Latest research shows that the Moon could be younger than previous estimates. The findings were published online Wednesday in the Nature journal.The prevailing theory of the Moon's origin is that it was created by a giant impact between a large planet-like object and the proto-Earth. The energy of this impact was sufficiently high that the Moon formed from melted material that was ejected into space. As the Moon cooled, this magma solidified into different mineral components. Analysis of lunar rock samples thought to have been derived from the original magma has given scientists a new estimate of the Moon's age.According to this theory for lunar formation, a rock type called ferroan anorthosite, or FAN, is the oldest of the Moon's crustal rocks, but scientists have had difficulty dating FAN samples. The research team used newly refined techniques to determine the age of a sample of FAN from the lunar rock that was brought back to Earth by the Apollo 16 mission in 1972.The team analyzed the isotopes of the elements lead and neodymium to place the FAN sample's age at 4.36 billion years. This figure is significantly younger than earlier estimates of the Moon's age that range as old as the age of the solar system at 4. 568 billion years. The new, younger age obtained for the oldest lunar crust is similar to ages obtained for the oldest terrestrial minerals -- zircons from western Australia -- suggesting that the oldest crusts on both Earth and Moon formed at approximately the same time, and that this time dates from shortly after the giant impact.This study is the first in which a single sample of FAN yielded consistent ages from multiple isotope dating techniques. This result strongly suggests that these ages pinpoint the time at which the sample crystallized."The extraordinarily young age of this lunar sample either means that the Moon solidified significantly later than previous estimates, or that we need to change our entire understanding of the Moon's geochemical history," Carnegie Institute of Science's geochemist and study author Richard Carlson said.

SHANGHAI, July 19 (Xinhua) -- Baidu Inc., the largest Chinese search engine based in Beijing, said Tuesday it closed a deal that allows the company to provide download services of music from Universal Music, Warner Music and Sony Music.According to the deal signed between Baidu and One Stop China (OSC), a joint venture of the three music companies, Baidu will pay them on a per-play and per-download basis for all tracks delivered through its MP3 server, said a press release provided by Baidu.Users can have access to the authorized music free of charge, and Chinese songs, both in Mandarin and Cantonese, and some global content provided by the three music companies will be included in the catalogue.Baidu also launched a social music platform called "Baidu ting!" through which users can obtain and share some music-related information and content.Li Xinzhe, CFO of Baidu, described the deal as a "milestone" that can benefit not only Baidu and its partners but also music lovers and the privacy-stricken industry.Wang Bin, secretary general of Copyright Union of Internet Society of China, predicted that it would have a demonstrative effect on the Internet sector.In 2008, Universal, Warner and Sony Music sued Baidu for at least 63.5 million yuan (9.8 million U.S. dollars) in copyright infringement.

SAN FRANCISCO, July 15 (Xinhua) -- U.S. microblogging platform Twitter on Friday marked its fifth anniversary since public debut."Twitter, then called Twttr, opened to the public five years ago today," the company said in a Tweet, a short message within 140 characters users are allowed to communicate on the website."Twttr is a new mobile service that helps groups of friends bounce random thoughts around with SMS," co-founder Biz Stone described the service in a blog post on July 13, 2006, two days before its public debut."There were 224 Tweets sent on July 15, 2006. Today, users send that many Tweets in less than a tenth of a second," said the San Francisco-based company.Twitter said more than 600,000 new users signed up on Thursday while it took it more than 16 months to reach the first 600,000 Twitter accounts.The tipping point for the service's popularity was the 2007 South by Southwest festival, a set of film, interactive and music festivals and conferences that take place every March in Austin, Texas. During the event, the Tweets sent per day grew from 20,000 to 60,000.With an estimated user base of 200 million worldwide, some 200 million Tweets are generated and 1.6 billion search queries are handled every day, the company said.According to research firm EMarketer, advertising sales on Twitter is expected to reach 150 million U.S. dollars this year. SharesPost, a secondary market for privately held companies, has assessed Twitter's current worth at 6.8 billion dollars.

WASHINGTON, July 15 (Xinhua) -- Researchers at Mount Sinai School of Medicine have found that grape seed polyphenols -- a natural antioxidant -- may help prevent the development or delay the progression of Alzheimer's disease.The research, led by Giulio Pasinetti, was published online Friday in the Journal of Alzheimer's Disease, which causes brain changes that gradually get worse.This is the first study to evaluate the ability of grape- derived polyphenols to prevent the generation of a specific form of amyloid (A) peptide, a substance in the brain long known to cause the neurotoxicity associated with Alzheimer's disease.In partnership with a team at the University of Minnesota, Pasinetti and collaborators administered grape seed polyphenolic extracts to mice genetically determined to develop memory deficits and A neurotoxins similar to those found in Alzheimer's disease. They found that the brain content of the A*56, a specific form of A previously implicated in the promotion of Alzheimer's disease memory loss, was substantially reduced after treatment.Previous studies suggest that increased consumption of grape- derived polyphenols, whose content, for example, is very high in red wine, may protect against cognitive decline in Alzheimer's. This new finding corroborates those theories."Since naturally occurring polyphenols are also generally commercially available as nutritional supplements and have negligible adverse events even after prolonged periods of treatment, this new finding holds significant promise as a preventive method or treatment, and is being tested in translational studies in Alzheimer's disease patients," said Pasinetti.In Alzheimer's disease, brain cells degenerate and die, causing a steady decline in memory and mental function.

WASHINGTON, June 2 (Xinhua) -- When humans see red, their reactions become both faster and more forceful, according to a new study published this week in the U.S. bimonthly journal Emotion.The findings may have applications for sporting and other activities in which a brief burst of strength and speed is needed, such as weightlifting. But the authors caution that the color energy boost is likely short-lived.The study measured the reactions of students in two experiments. In the first, 30 fourth-through-10th graders pinched and held open a metal clasp. Right before doing so, they read aloud their participant number written in either red or gray crayon. In the second experiment, 46 undergraduates squeezed a handgrip with their dominant hand as hard as possible when they read the word "squeeze" on a computer monitor. The word appeared on a red, blue, or gray background.In both scenarios, red significantly increased the force exerted, with participants in the red condition squeezing with greater maximum force than those in the gray or blue conditions. In the handgrip experiment, not only the amount of force, but also the immediacy of the reaction increased when red was present.The colors in the study were precisely equated in hue, brightness, and chroma (intensity) to insure that reactions were not attributable to these other qualities of color."Red enhances our physical reactions because it is seen as a danger cue," explains coauthor Andrew Elliot, professor of psychology at the University of Rochester and a lead researcher in the field of color psychology. "Humans flush when they are angry or preparing for attack," he explains. "People are acutely aware of such reddening in others and it's implications."But threat is a double-edged sword, argue Elliot and coauthor Henk Aarts, professor of psychology at Utrecht University, in the Netherlands. Along with mobilizing extra energy, "threat also evokes worry, task distraction, and self-preoccupation, all of which have been shown to tax mental resources," they write in the paper.In earlier color research, exposure to red has proven counterproductive for skilled motor and mental tasks: athletes competing against an opponent wearing red are more likely to lose and students exposed to red before a test perform worse.

来源：资阳报