辽阳大功率工业吸尘器(济宁大型工业吸尘器) (今日更新中)

Beijing, Sept. 6 (Xinhua) -- A sperm donation scandal disclosed recently has aroused growing concern in the United States.According to the New York Times' report, Ryan Kramer, the son of a donor, found that he has more than 150 half-siblings - they are all the children of the same donor."It's wild when we see them all together - they all look alike," said Cynthia Daily, mother of Kramer.As more women choose to have children on their own, the demand for sperm donors has surged.Some sperm banks are earning huge profits by allowing too many mothers to receive sperms from the same popular donors, according to the report.And this trend will lead to risks: rare genetic diseases could be spread more widely, and the children of the same donor could meet and, unbeknownst to them, commit incest, medical experts warned.Parents and donors are calling for a tighter regulation so that donor children can know more about their donors, and the number of kids from each donor can be limited.

WASHINGTON, July 5 (Xinhua) -- Intake of high levels of folate, a water-soluble B vitamin that occurs naturally in food, may reduce colorectal cancer risk, according to a new study published Tuesday in Gastroenterology, the official journal of the American Gastroenterological Association (AGA) Institute. "We found that all forms and sources of folate were associated with lower risk of colorectal cancer," said lead author Victoria Stevens, of the American Cancer Society. "The strongest association was with total folate, which suggests that total folate intake is the best measure to define exposure to this nutrient because it encompasses all forms and sources."Total folate includes naturally occurring food folate and folic acid from fortified foods and dietary supplements.The research team investigated the association between folate intake and colorectal cancer among 99,523 participants in the Cancer Prevention Study II Nutrition Cohort; a total of 1,023 participants were diagnosed with colorectal cancer between 1999 and 2007, a period entirely after folate fortification began. Neither higher nor lower risk was observed during the first two years of follow-up (1999 to 2001), while associations were statistically significantly inverse for the subsequent years (2002 to 2007). The findings of this study add to the epidemiologic evidence that high folate intake reduces colorectal cancer incidence.Folates are essential nutrients needed to make components used for functions required for normal cell growth, including DNA synthesis and repair. Because these processes are critical for cell growth and differentiation, the relationship between folate intake and cancer development has been investigated in several cancers, and most extensively in colorectal cancer.

LOS ANGELES, June 5 (Xinhua) -- A latest study has found no evidence that screening for ovarian cancer may reduce the risk of dying from the disease, it was reported on Sunday.Screening, however, does increase the likelihood of unnecessary invasive procedures, according to researchers at the University of Utah.The researchers presented their findings at an on-going meeting of the American Society of Clinical Oncology in Chicago, The Los Angeles Times said.Researchers studied 78,216 women, ages 55 to 74, who participated in the National Cancer Institute's Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Half of the women received the usual care from their OB-gyns, and half received a CA 125 screening every year for six years and an ultrasound every year for four years. They were then followed for a maximum of 12 years.The researchers observed 212 ovarian cancers in the screened group and 176 in the normal care group. There were 118 ovarian cancer deaths in the screened group and 100 in the normal care group. The differences were not statistically significant. Overall, there were 2,924 deaths from all causes in the screened group and 2,914 in the normal care group.But the researchers also observed that 3,285 women had false- positive diagnoses from the screening. Among those, 1,080 underwent surgery that included an oophorectomy (surgical removal of one or both ovaries). Fifteen percent of those who had surgery developed major complications as a result. Overall, 1,771 women in the screened group (7.7 percent) had an oophorectomy, compared with 1,304 in the normal care group (5.8 percent)."We conclude that annual screening for ovarian cancer ... does not reduce disease-specific mortality in women at average risk for ovarian cancer but does increase invasive medical procedures and associated harms," the researchers said in the study.New data presented at the meeting also showed that the widely used cancer drug Avastin can improve treatment of ovarian cancer, The Times said.About 21,880 American women are diagnosed with ovarian cancer each year and about 13,850 die from it, according to the American Cancer Society. Because it produces few symptoms, the disease is typically not diagnosed until it has become advanced and spread throughout the body. As a result, five-year survival is only about 30 percent, and the disease is one of the five most deadly cancers among women. Being able to detect the cancer at an earlier stage when it might be more curable could thus, theoretically, improve the survival rate.The tests most commonly used to detect ovarian cancer include a transvaginal ultrasound to look for tumor masses and a blood test that screens for increased levels of a tumor marker called CA 125.

BEIJING, July 26 (Xinhuanet) -- Hong Kong scientists announced that they had determined the idea of time travel is impossible by proving nothing can travel faster than the speed of light.The finding is contained in a study done by a research team from Hong Kong University of Science and Technology. The study was published Monday in a scientific journal "Physical Review Letters" in the United States."The study, which showed that single photons also obey the speed limit c, confirms Einstein's causality, that is, an effect cannot occur before its cause," the university said on its website."By showing that single photons cannot travel faster than the speed of light, our results bring a closure to the debate on the true speed of information carried by a single photon." said Professor Du Shengwang, who led the study.The possibility of time travel was raised 10 years ago when scientists discovered the optical pulses in some specific medium might propagate information in a faster-than-light speed."Our findings will also likely have potential applications by giving scientists a better picture on the transmission of quantum information." Du said.

CHENGDU, Sept. 20 (Xinhua) -- A United Nations official said Tuesday that she hopes China will take every opportunity to reinforce, support and lead the UN's agenda and "infuse it with strength and wisdom.""The more China gives, the better the UN can become," said Renata Lok-Dessallien, UN Resident Coordinator and United Nations Development Program (UNDP) Resident Representative in China, at the Seminar in Memory of the 40th Anniversary of the Resumption of Lawful Rights of China in the United Nations.The three-day seminar from Sept. 19 to 21 is being held in the city of Chengdu in southwest China's Sichuan Province. About 100 UN and Chinese officials are gathering to discuss China's role in the UN, as well as the UN's role in global diplomacy.Lok-Dessallien said that the General Assembly Resolution of Oct. 25, 1971 was an "important milestone in China's international relations and in the history of the United Nations.""It restored the rights of the People's Republic of China in the United Nations and marked China's entry to the world stage," she said.Steven Sabey, a senior policy advisor from the UNDP's China office, said that China plays an important role in facilitating cooperation about the member states of the United Nations."China needs the United Nations, and the United Nations also needs China," said Wu Hailong, China's assistant minister of foreign affairs."We must recognize that as the largest developing country in the world, China needs to manage its domestic affairs first, as this can have a positive effect on humanity as a whole," Wu said.As China's role in the world continues to grow and evolve, the UN's role in China will also grow, according to Lok-Dessallien."As China's development trajectory continues to evolve, we are entering significantly new territory in the UN-China relationship," she said.Sabey said that he hopes China will strengthen its cooperation with the United Nations in order to further improve intercultural communication and allow China to contribute more to other developing countries."The United Nations is committed to continuing to deepen and strengthen our partnership as we tackle the many global challenges ahead," said Lok-Dessallien.

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