中山哪里有外痔医院(中山便血无痛属于什么症状) (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.

SYDNEY, Aug. 16 (Xinhua) -- People sitting in front of TV for hours on end could shorten their life expectancy by almost five years, according to an Australian study published on Tuesday by the British Journal of Sports Medicine.Researchers from the University of Queensland estimate that for every hour adults spend in front of TV, their life expectancy shortens by almost 22 minutes.Those who watched six hours a day lived 4.8 years less than those who don't watch TV.The study is the first in Australia to look into how TV habits affect longevity.The Australian researchers found that watching TV could have a similar negative impact on life expectancy to that of obesity, smoking and low physical activity."People don't realize how it all adds up," the study's lead author Dr. Lennert Veerman told the Australian Associated Press (AAP)."They should try not to watch too much TV and find alternative things to do, preferably things that are light activities," Veerman said.The study was based on data from the Australian Diabetes, Obesity and Lifestyle study and asked more than 11,000 people aged over 25 about their weekly TV viewing time.The study found that in 2008 Australian adults watched 9.8 billion hours of TV."These findings suggest that substantial loss of life may be associated with prolonged TV viewing time among Australian adults," the study said."TV viewing time may have adverse health consequences that rival those of lack of physical activity, obesity and smoking; every single hour of TV viewed may shorten life by as much as 22 minutes," it said."With further corroborative evidence, a public health case could be made that adults also need to limit the time spent watching TV."Australians are recommended to spend at least 30 minutes a day doing moderate-intensity physical activity to reduce an increased risk of developing cardiovascular disease.

BEIJING, July 11 (Xinhuanet) -- U.S. federal government officially announced that it denied the medical use of marijuana."Department of Health and Human Services concluded that marijuana has a high potential for abuse, has no accepted medical use in the United States, and lacks an acceptable level of safety for use even under medical supervision," U.S. Department of Justice declared Friday.The announcement will keep marijuana in the classification of dangerous, addictive drug as heroin.The decision comes almost nine years after medical marijuana advocates asked the government to reclassify marijuana, as its therapeutic effectiveness in treating some diseases and relieving pain of patients.Joe Elford, the chief counsel for Americans for Safe Access (ASA), said he was not surprised by the government's disapproval."It is clearly motivated by a political decision that is anti-marijuana," He noted.This is the third petition to reclassify marijuana has failed to be approved. The former two were filed in 1972 and in 1995, respectively.

HAVANA, Aug. 15 (Xinhua) -- Cuba's Ministry of Public Health launched an intensive sanitation campaign Monday against the Aedes Aegypti mosquito, which can spread dengue fever.The operation, which is running through Sept. 15, will cover the most vulnerable cities in the country, including the capital Havana and the eastern city Guantanamo.Deputy Health Minister Luis Estruch stressed the importance of the prevention campaign and urged all families to check their houses for mosquitoes each week.Maria Guadalupe Guzman, director of the Pan-American and World Health Organization Cooperation Center for the Study of Dengue and Its Vector at the Pedro Kouri Institute of Tropical Medicine, said the epidemiological situation in the country is stable. However, she warned that an epidemic outbreak is still possible in the island state, given the high temperatures and heavy rains in the eastern areas, and drought in the west.Cuba, along with Chile and Uruguay, are the only Latin American countries where dengue is not endemic.In 1981, the country suffered its worst dengue outbreak in history, which left 158 dead.

SAN FRANCISCO, June 20 (Xinhua) -- Google and the British Library announced Monday that the Internet search giant will digitize 250,000 out-of-copyright books from the library's collections, making up to 40 million pages from 1700 to 1870 available to the public online.In a joint statement, the British Library and Google said they will work in partnership over the coming years to deliver the content free through Google Books and the library's website, and full text search, download and reading will be available. Google will cover all digitization costs.The project is going to cover a huge range of printed books, pamphlets and periodicals dated 1700 to 1870, a period of political and technological turmoil, from the Industrial Revolution to the French Revolution, from the introduction of the income tax in Britain and the invention of the telegraph and railway.It will include material in a variety of major European languages and will focus on books that are not yet freely available in digital form online, said the statement.Since December 2004, Google has announced partnership with some 40 high-profile university and public libraries, planning to digitize and make available some 15 million volumes within a decade through Google Books service.The project has triggered controversy as publisher and author associations oppose the plan to put copyrighted titles online in a class action lawsuit.

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