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BEIJING, Sept. 2 (Xinhuanet) -- The amount of space junk orbiting the Earth could cause fatal leaks in spaceships or destroy valuable satellites, according to a report released by the U.S. National Research Council.Computer models have shown that the number of orbital debris "has reached a tipping point, with enough currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures," the Research Council said Thursday.So far, there are 22,000 pieces of debris large enough to track from the ground, but smaller objects could still cause serious damage.New international regulations are needed to limit space junk.And more researches should be done to test the possible use of launching magnetic nets or giant umbrellas to push the debris further towards the Earth where it would burn up, or into a higher but safer orbit.

LOS ANGELES, July 18 (Xinhua) -- U.S. scientists have proven that oncogenes can change normal cells into stem-like cells, paving the way to a safer and more practical approach to treating diseases like multiple sclerosis and cancer with stem cell therapy.In a collaborative study, researchers from the Keck School of Medicine of the University of Southern California (USC), and the Children's Hospital of Orange County (CHOC) in California and Good Samaritan Hospital Medical Center in New York have successfully converted human skin cells into brain cells by suppressing the expression of p53, a protein encoded by a widely studied oncogene. This suggests that p53 mutation helps determine cell fate -- good or bad -- rather than only the outcome of cancer.Oncogenes are generally thought to be genes that, when mutated, change healthy cells into cancerous tumor cells.Study findings were appearing Monday on the website of the American Association for the Advancement of Science (AAAS)."The reality may be more complicated than people think," said Jiang F. Zhong, Ph.D., assistant professor of pathology at the Keck School. "What is a stem cell gene? What is a cancer gene? It may be the same thing.""When you turn off p53, people think the cell becomes cancerous because we tend to focus on the bad thing," Zhong said. "Actually, the cell becomes more plastic and could do good things, too. Let's say the cell is like a person who loses his job (the restriction of p53). He could become a criminal or he could find another job and have a positive effect on society. What pushes him one way or the other, we don't know because the environment is very complicated."Stem cells can divide and differentiate into different types of cells in the body. In humans, embryonic stem cells differentiate into three families, or germ layers, of cells. The reasons why and how certain stem cells differentiate into particular layers are not clearly understood. However, from those layers, tissues and organs develop. The endoderm, for example, leads to formation of the stomach, colon and lungs, while the mesoderm forms blood, bone and heart tissue. In its study, Zhong's team examined human skin cells, which are related to brain and neural cells from the ectoderm.When p53 was suppressed, the skin cells developed into cells that looked exactly like human embryonic stem cells. But, unlike other man-made stem cells that are "pluripotent" and can become any other cells in the body, these cells differentiated only into cells from the same germ layer, ectoderm."IPSCs (induced pluripotent stem cells) can turn into anything, so they are hard to control," Zhong said. "Our cells are staying within the ectoderm lineage."Zhong said he expects that suppressing other oncogenes in other families of cells would have the same effect, which could have critical significance for stem cell therapy. Future research should focus on determining which genes to manipulate, Zhong said.The study is slated to appear in the Proceedings of the National Academy of Sciences later this month, according to AAAS.

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.

BEIJING, Aug. 22 (Xinhuanet) -- Researchers have discovered how a human egg captures an incoming sperm for fertilization, paving the way to help couples suffering from infertility, according to media reports on Monday.An international team of researchers found that a sugar chain known as the sialyl-lewis-x sequence (SLeX) makes the outer coat of the egg “sticky,” which has proven to be helpful in binding the egg and the sperm.As a result, this observation has filled in a huge gap in the understanding of fertility and provides hope for ultimately helping couples who currently cannot conceive.Scientists and doctors know that a sperm identifies an egg when proteins on the head of the sperm match and bind to a series of specific sugars in the egg’s outer coating. With a successful match of proteins, the outside surfaces of the sperm and egg then bind together before merging, which is then followed by delivery of sperm’s DNA into egg.To identify this molecules, the researchers used ultra-sensitive mass-spectrometric imaging technology to observe and identify which molecules are most likely to be key in the binding process.They experimented with a range of synthesised sugars in the laboratory and found that it is SLeX that specifically binds sperm to an egg.According to the World Health Organisation, infertility affects about 15 percent of reproductive-aged couples around the world and almost one in every seven couples in Britain has problems conceiving a child for various reasons.

UNITED NATIONS, Sept. 19 (Xinhua) -- Mohammad Hossein Niknam, acting minister of health in international affairs of Iran, said here on Monday that his country is working to prevent and counteract the non-communicable diseases (NCDs), which have had significant effect on the population."NCDs have traditionally been more prevalent in affluent societies," he said. "However, they are increasingly becoming common in many developing countries, and in particular among the less affluent groups. The Eastern Mediterranean Region (EMRO) as others is suffering a heavy burden of NCD diseases and Iran is no exception: the total burden of disease for NCDs is 45 percent for males and 33 percent for females."Niknam's statements came as he addressed the UN General Assembly High-Level Meeting on Prevention and Control of Non- communicable Diseases."This timely high-level event provides us with an ideal platform to share views, information, ideas and experiences, to come up with remedial proposals and to forge effective collaborative partnerships in the implementation of realistic but effective health development programs in common areas of concern pertaining to the non-communicable diseases," Niknam said.He explained that Iran is implementing a series of programs in order to reduce the frequency and impacts of NCDs."As part of these programs I would like to mention prevention and control of common NCDs risk factors, imposition of taxes to curtail unhealthy habits such as tobacco consumption, execution of mass public information and educational campaigns, fostering food industry regulations, screening of blood pressure levels and high glucosemia," he said.Iran has created a Non-Communicable Diseases Risk Factor Surveillance System, according to Niknam. This system, in place since 2004, has conducted six large-scale surveys to gather information helpful to public health."Further, comprehensive cumulative national data has been compiled based on age, sex and location to facilitate effective monitoring and implementation of policies geared towards control and prevention of NCDs," Niknam said.Iran is conducting many other integrated NCD control and prevention programs, such as, to name a few, a Cardiovascular Diseases Control Program for rural areas; a National Cancer Control Program focusing on breast and colorectal cancers; and a Diabetes Control and Prevention Program that targets both rural and urban areas.Niknam ended his statement by noting that Iran has held regional consultations on the NCD issue."I would like to conclude my remarks by mentioning that as a sign of its commitment to promote regional and international cooperation, the Islamic Republic of Iran hosted on 25-26 October 2010 in Tehran the first regional meeting of a series of the regional consultations held by WHO (World Health Organization) on the prevention and control of NCDs," he said. "In our understanding, only through closer and meaningful collaboration at all levels, especially in areas such as legislation, resource mobilization and information and knowledge sharing, we may success in our endeavor to prevent and combat NCDs."

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