呼和浩特较好的肛肠医院在那(呼市痔疮专科的医院) (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.

WELLINGTON, May 31 (Xinhua) -- New Zealand agricultural produce regulators cleared an Auckland-based firm that exported infant formula to China of food safety concerns, just hours after confirming they had launched an investigation.The clarification came the same day Kiaora New Zealand International, marketers of Heitiki infant formula, apologized for using a Maori name and icon on its product packaging.The Ministry of Agriculture and Forestry (MAF) issued a statement Tuesday to say Kiaora New Zealand had been cleared of food safety and export regulations concerns, but an investigation into the labeling and marketing of Heitiki would continue.The MAF issued a statement earlier Tuesday confirming reports it was investigating the product's safety, but MAF compliance and enforcement director Geoff Allen said in a later statement the investigation had been underway for about 10 days."The investigation was triggered by our internal surveillance. The investigation was primarily on whether there was a food safety issue, and I'm pleased to report that no food safety issues were identified," said Allen.Nothing "untoward" was identified in the origin and export destination of Heitiki-branded products, which were manufactured in New Zealand according to legal requirements, said Allen."The investigation has now turned to the labeling and marketing of the product. This aspect is ongoing, and seeks to identify anything in the labeling or marketing that is inaccurate or misleading.

BEIJING, Aug. 16 (Xinhuanet) -- Almost one in four Chinese students aged between 12 and 14 have tried smoking, according to the results of a survey released by the Chinese Association on Tobacco Control (CATC).The survey, carried out among 38,839 students and 6,503 teachers from middle and high schools in 11 provinces across the country between May and June, showed that 22.5 percent of students aged between 12 and 14 had tried smoking and that 15.8 percent of middle and high school students smoke regularly."There are definitely quite a number of boy students in my class who smoke regularly as some have been found smoking outside campus during lunch break," said Li Xiaolan, an English teacher from a high school in Shanghai. The survey also found that 39 percent of students took their first cigarette from their classmates."It was quite common to smoke with my classmates at school and we usually smoked in toilets or in corners of the playground after lunch," said Zhou Guangrong, a 22-year-old university student from Guiyang, Guizhou province, who started smoking when he was 12.The majority of student smokers buy cigarettes themselves and about 76 percent of the adolescent smokers said that there is at least one cigarette shop within 200 meters from their school."When I was a student at middle and high schools, they were surrounded by cigarette shops," said Zhou who used to smoke two cigarettes per day in primary school and two packs per week in middle and high school."We're keen to show that more adolescents are starting smoking much younger than before, and that we need to minimize the number of young smokers," said Duan Jiali, secretary-general of the youth tobacco control commission under CATC. Duan added that teachers and parents should set a good example for teenagers by not smoking in front of them at school or at home, which is the most influential way of stopping adolescents from smoking.China banned smoking in 16 types of public indoor venues - including hospitals, schools, bars, restaurants and hotels - on May 1 in an attempt to curb tobacco use in the country with the world's largest number of smokers.Currently, there are more than 300 million smokers in China, and about 1.2 million people die from smoking-related diseases every year, accounting for one-fifth of the world's total, according to statistics from the World Health Organization."Meanwhile, about 540 million people are exposed to secondhand smoke, 48.9 percent of which are adolescents (from 15 to 19 years old)," said Xu Guihua, deputy director of the CATC."It's essential and urgent for us to control the number of adult smokers who potentially tempt adolescents to smoke."

WELLINGTON, June 7 (Xinhua) -- Scientists in New Zealand have developed a new drug to fight previously untreatable hypoxic cancer tumors, which form in areas of the body starved of oxygen.The researchers at the Auckland University have entered an agreement for the clinical development of CEN-209, which was developed over 10 years of research, said a statement from the university Tuesday.CEN-209 was designed to enhance the effectiveness of radiotherapy and chemotherapy in solid hypoxic tumors, which were resistant to standard cancer therapies, said the statement. In lung cancer patients for example, about half of tumors had hypoxic regions.The new drug worked by damaging the DNA of hypoxic cancer cells, while leaving normal, healthy tissues alone.CEN-209 was designed and created by researchers at the university's Auckland Cancer Society Research Centre (ACSRC), using computer models of drug transport within tumors to accurately predict the anti-tumor activity of the drugs."Our computer models of drug transport developed in-house allowed the synthetic chemists to test their design theories and considerably shortened the discovery process," said Associate Professor Michael Hay, who led the ACSRC research chemists."CEN-209 improves markedly on previous agents in this class in terms of its ability to penetrate tumors, and this is reflected by its improved activity in the laboratory, when combined with long or short courses of radiotherapy," said researcher Professor Bill Wilson.Under the agreement between the university's Auckland UniServices Ltd. and California-based Centella Therapeutics, Inc., a subsidiary of Varian Medical Systems, Inc., Centella will have exclusive rights to CEN-209, which it will develop and trial with Cancer Research UK.The work on CEN-209 is the culmination of a program initiated with funding from the U.S. National Cancer Institute, and more recently from the Maurice Wilkins Centre for Biodiscovery. Ongoing preclinical research on CEN-209 and a backup compound was funded by grants from the Auckland Medical Research Foundation, Genesis Oncology Trust and Health Research Council of New Zealand, said the statement.

LOS ANGELES, June 24 (Xinhua) -- Near-Earth asteroid 2011 MD will whip past Earth on June 27, but will not pose any threat, NASA's Jet Propulsion Laboratory (JPL) said on Friday.The asteroid will pass only 12,000 kilometers (7,500 miles) above the Earth's surface at about 9:30 EDT, according to JPL in Pasadena, Los Angeles.This small asteroid, only 5-20 meters in diameter, is in a very Earth-like orbit about the Sun, but an orbital analysis indicates there is no chance it will actually strike Earth on Monday, JPL said.If a rocky asteroid the size of 2011 MD were to enter Earth's atmosphere, it would be expected to burn up high in the atmosphere and cause no damage to Earth's surface, said JPL.The accompanying diagram gives a view of the asteroid's trajectory from the general direction of the Sun. This view indicates that 2011 MD will reach its closest Earth approach point in extreme southern latitudes (in fact over the southern Atlantic Ocean), according to JPL. The incoming trajectory leg passes several thousand kilometers outside the geosynchronous ring of satellites and the outgoing leg passes well inside the ring, JPL said.For a brief time, it may be bright enough to be seen even with a modest-sized telescope.One would expect an object of this size to come this close to Earth about every six years on average.The asteroid was discovered by the LINEAR near-Earth object discovery team observing from Socorro, New Mexico.

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