宜宾哪里做双眼皮比较好?宜宾双眼皮好割双眼皮,宜宾怎么可以脱毛,宜宾压双眼皮去哪家医院好,宜宾美容整形隆鼻,宜宾光子脱毛周期,宜宾眼袋抽脂注意事项,宜宾双眼皮埋线大约多少钱

WASHINGTON, June 16 (Xinhua) -- Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage. New research by a team of scientists at the University of Rochester has unveiled an important new mechanism that allows cells to recognize when they are under stress and prime the DNA repair machinery to respond to the threat of damage.Their findings will be published Friday in journal Science. Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage.The scientists, led by biologists Vera Gorbunova and Andrei Seluanov, focused on the most dangerous type of DNA damage -- double strand breaks. Unrepaired, this type of damage can lead to premature aging and cancer. They studied how oxidative stress affects efficiency of DNA repair. Oxidative stress occurs when the body is unable to neutralize the highly-reactive molecules, which are typically produced during routine cellular activities.The research team found that human cells undergoing oxidative stress synthesized more of a protein called SIRT6. By increasing SIRT6 levels, cells were able to stimulate their ability to repair double strand breaks. When the cells were treated with a drug that inactivated SIRT6, DNA repair came to a halt, thus confirming the role of SIRT6 in DNA repair. Gorbunova notes that the SIRT6 protein is structurally related to another protein, SIR2, which has been shown to extend lifespan in multiple model organisms."SIRT6 also affects DNA repair when there is no oxidative stress," explains Gorbunova. "It's just that the effect is magnified when the cells are challenged with even small amounts of oxidative stress."SIRT6 allows the cells to be economical with their resources, priming the repair enzymes only when there is damage that needs to be repaired. Thus SIRT6 may be a master regulator that coordinates stress and DNA repair activities, according to Gorbunova.

BEIJING, Aug. 13 (Xinhua) -- The quality of the products China exported to the European Union (EU) improved during the first half of this year due to strict quality control measures, according to quality control authorities.The number of quality complaints made by the EU regarding Chinese imports declined by 45 percent in the first half of 2011, according to the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ).The administration attributed the improved quality to its nationwide crackdown on counterfeited and substandard products.The administration launched a nationwide quality checkup in the first half of this year. Of the 4,815 batches of products that the quality control authorities checked between January and June, just 9.4 percent failed quality tests, 1.7 percentage points lower than that of the same period of last year, according to the administration.A total of 218,000 counterfeiting cases have been investigated so far this year, involving goods worth a total of 9.5 billion yuan (1.49 billion U.S. dollars), the administration said.

WASHINGTON, June 6 (Xinhua) -- Forests in many regions are becoming larger carbon sinks thanks to higher density, U.S. and European researchers say in a new report.In Europe and North America, increased density significantly raised carbon storage despite little or no expansion of forest area, according to the study, led by Aapo Rautiainen of the University of Helsinki, Finland, and published Monday in the on- line, open-access journal PLoS One.Even in the South American nations studied, more density helped maintain regional carbon levels in the face of deforestation.The researchers analyzed information from 68 nations, which together account for 72 percent of the world's forested land and 68 percent of reported carbon mass. They conclude that managing forests for timber growth and density offers a way to increase stored carbon, even with little or no expansion of forest area."In 2004 emissions and removals of carbon dioxide from land use, land-use change and forestry comprised about one fifth of total emissions. Tempering the fifth by slowing or reversing the loss of carbon in forests would be a worthwhile mitigation. The great role of density means that not only conservation of forest area but also managing denser, healthier forests can mitigate carbon emission," says Rautiainen.