沈阳高级臀部肌肉注射及对比模型(南平高级外科缝合腿肢模型) (今日更新中)

LOS ANGELES, June 3 (Xinhua) -- Eating earth may protect the stomach against toxins, parasites and pathogens, a new study suggests.To examine the possible benefits from eating earth, researchers at Cornell University analyzed reports from missionaries, plantation doctors, explorers, and anthropologists to put together a database of more than 480 cultural accounts of geophagy -- the eating of earth.The database includes as many details as possible about the circumstances under which earth was consumed, and by whom. The researchers could then use patterns in the data to evaluate each potential explanation.Studies in the database indicate that geophagy is common even when food is plentiful. Moreover, when people eat dirt they tend to eat only small quantities that are unlikely to fill an empty stomach.The database shows that geophagy is documented most commonly in women in the early stages of pregnancy and in pre-adolescent children. Both categories of people are especially sensitive to parasites and pathogens, according to the researchers.In addition, geophagy is most common in tropical climates where foodborne microbes are abundant. Finally, the database shows that people often eat earth during episodes of gastrointestinal stress.It's unlikely the intestinal problems are caused by the dirt itself because the type of clay people usually eat comes from deep in the ground, where pathogens and parasites are unlikely to contaminate it. Plus, people usually boil the clay before eating it.More study would be helpful to confirm the protection hypothesis, the researchers say, but the available data at this point clearly support it over the other explanations for eating earth."We hope this paper stimulates (more) research," said Sera Young, a researcher at Cornell University and the study's lead author. "More importantly, we hope readers agree that it is time to stop regarding geophagy as a bizarre, non-adaptive gustatory mistake.""With these data, it is clear that geophagy is a widespread behavior in humans ...that occurs during both vulnerable life stages and when facing ecological conditions that require protection."The study is appearing in the June issue of The Quarterly Review of Biology.

People look at a W154 Mercedes Benz racing car at a vintage car show marking the German car maker's 125 anniversary at the former Tempelhof airport in Berlin, August 27, 2011.

SAN FRANCISCO, Sept. 12 (Xinhua) -- Amazon.com Inc. is talking with book publishers to launch a rental subscription service for digital books, U.S. media reported on Monday.Several publishing executives said they aren't enthusiastic about the idea because it could lower the value of books and it could also strain their relationships with other retailers that sell their books, The Wall Street Journal quotes people familiar with the matter in a report.The Seattle-based company is considering a digital book library featuring old titles, which would be available to Amazon Prime subscribers, who currently pay 79 U.S. dollars a year for access to digital library of movies and TV shows and unlimited two-day shipping, said the report.Amazon would offer book publishers a substantial fee and could limit the amount of books that Amazon Prime customers could read for free every month, the report cited some sources as saying.The online retailing giant makes the popular electronic reader Kindle and is also reported to launch a color touchscreen tablet before October to compete with Apple's iPad and other devices in the increasingly crowded tablet computer market.The proposal is another sign that retailers are looking for more ways to deliver content digitally as customers increasingly read book and watch TV on personal computers, tablets and other electronic devices, said The Wall Street Journal report.

BEIJING, Sept. 14 (Xinhuanet) -- Scientists had discovered the fossils of a new species of ancient carnivorous fish, National Geographic reported Monday.The newly-found ancient fish, "Laccognathus embryi", is a 1.8-meter-long predator, which was "waiting to lunge out to grab whatever was in front of it," said study co-author Ted Daeschler, a vertebrate zoologist at the Academy of Natural Sciences in Philadelphia, the U.S..It had a jaw filled with sharp teeth that were 1.5 inches long, the Journal of Vertebrate Paleontology described.The fish lived in the Devonian period, 415 to 360 million years ago, which "was a fish-eats-fish kind of world," Daeschler said. "There was a real arms race going. If you didn't have good armor on your body, you were very vulnerable.""It's not just finding the animal - it's also placing the animal in its evolutionary crucible," Daeschler added.Its closest living relative is the lungfish which can survive in the drought, scientists said.Scientists hope the finding can help in their study on the revolution of fishes as well as other species.

SHENZHEN, June 4 (Xinhua) -- Chinese scientists who have fully sequenced the genome of the new E. Coli spreading through Europe said Saturday they found genes in the bacteria that gave it resistance to eight classes of antibiotics.Researchers with the Beijing Genomics Institute, the world's largest DNA sequencing center, have found genes in the newly identified 0104 strain of E. Coli bacteria that made it resistant to major classes of antibiotics including sulfonamide, cephalothin, penicillin and streptomycin.This helped explain why doctors in Europe had difficulties in fighting the bug that has killed 18 people and sickened nearly 2,000, BGI's major research arm in Shenzhen said on its website Saturday.This would help doctors choose right medicines for the treatment, it said.The researchers are developing a diagnostic kit which will be used to detect the bacteria and prevent the epidemic from spreading further.The Chinese researchers obtained DNA samples of the bacteria from collaborating scientists in Germany and fully sequenced its genome in three days this week.They announced on Thursday the E. Coli spreading through Europe was "a new strain of bacteria that is highly infectious and toxic".The 0104 strain of E. Coli was not previously involved in any E. Coli outbreaks. However, it has 93 percent sequence similarity with the EAEC 55989 E. Coli strain which was isolated in the Central African Republic and known to cause seriously diarrhea, BGI said.The source of the outbreak is unknown, but scientists say it is highly likely to have originated in contaminated vegetables or salad in Germany.

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