濮阳东方男科专不专业(濮阳东方男科医院可靠) (今日更新中)

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.

WASHINGTON, July 10 (Xinhua) -- U.S. space shuttle Atlantis docked with the International Space Station on Sunday morning after nearly two days of flight.Commander Christopher Ferguson guided space shuttle Atlantis to a docking with the station at 11:07 a.m. EDT (1507 GMT) when the two spacecrafts were flying 240 miles up over east of New Zealand, according to NASA.This was the 12th and final time Atlantis docked to the space station. It was the 46th shuttle docking to a space station, nine to the Russian Mir station and 37 to the International Space Station.The space shuttle Atlantis is seen with part of the structure of the International Space Station in the foreground and the earth in the background as it approaches the station for docking in this still image from NASA TV July 10, 2011. The shuttle and station crews will open hatches and hold the traditional welcome ceremony at about 1:19 p.m. EDT (1719 GMT). The combined crew of 10 will begin more than a week of docked operations, transferring vital supplies and equipment to sustain station operations once the shuttles are retired.Atlantis lifted off on Friday morning from Kennedy Space Center in Florida, on the 135th and final flight in NASA's shuttle program.It is the 33rd voyage for Atlantis. Its return to the earth later this month will mark the end of the 30-year shuttle program.

SUVA, July 25 (Xinhua) -- There are 400,000 people suffering from anaemia in Fiji with a total of population at about 800,000 people, according to the Health Ministry on Monday.Health Minister Doctor Neil Sharma told media that currently 60 per cent of children less than five years old are iron deficient, 40 per cent of women lack iron while 20 per cent of men suffer from iron deficiency in the island nation.Sharma, therefore, called on every family to grow local, eat local and move back to our traditional food habits, telling anaemic, "Do not forget to take your iron tablets."National Advisor Non-Communicable Diseases, Dr Isimeli Tukana also told media on Monday that strategies would include implementing the Food and Health Guidelines for the country in all clinics.All females are supposed to take their iron medication while all pre and primary school children will be given iron supplementation, he added.According to Fiji's Agriculture and Nutrition Department, the island nation, which is in transition towards increasing industrialization, is facing nutritional problems associated with both under-nutrition and over-nutrition.Lack of access to food due to economical shortages is one of the major causes of malnutrition in the country as one quarter of the population is living below the poverty line and most are living in illegal squatter settlements in search of employment and educational opportunities in urban areas.The problem of over-nutrition, on the other hand, may be associated with the change in the consumption patterns towards a diet high in energy but low in fibre, vitamins and minerals and a sedentary lifestyle.

SAN FRANCISCO, Sept. 13 (Xinhua) -- Researchers in San Francisco, U.S. have found in a latest study that bisphenol A (BPA) and methylparaben, two chemicals commonly used in consumer products, can interfere with the breast cancer drugs, local media reported on Tuesday.In the study, doctors from California Pacific Medical Center in San Francisco found that healthy breast cells from high-risk patients started to find ways to bypass breast cancer drugs after they were exposed to BPA and methylparaben in the lab.The cells exposed to the two chemicals kept growing and didn't die after they were introduced with Tamoxifen, a current standard drug therapy for female breast cancer and most common used treatment for male breast cancer, Dr. William Goodson, lead author of the study, told San Francisco Chronicle.Goodson said that BPA and methylparaben not only mimic estrogen 's ability to drive cancer, but appear to be even better than the natural hormone in bypassing the ability of drugs to treat it. The finds have been published online in the British medical journal Carcinogenesis.The research shows more evidence of safety issues of BPA, a chemical primarily used to make plastic baby bottles, food containers, household electronics and etc, as well as the less known methylparaben, a chemical preservative used in cosmetics and other personal care products.The researchers noted that the breast cancer rates have been growing by about the same amount in men as in women over the past three decades. Scientists have been looking at environmental causes for the disease and wondering where the hormones are coming from.Goodson said BPA and methylparaben are used so widely and even found in household dust, noting that it is still unknown whether the effects of exposure to the chemicals are reversible.Since 2008, several governments issued reports questioning the negative health effects of BPA, especially raising concerns regarding exposure of fetuses, infants and children. BPA use has been banned in baby bottles in a lot of countries and regions.As for methylparaben, the U.S. Food and Drug Administration said on its website that "at the present time there is no reason for consumers to be concerned about the uses of cosmetics containing parabens (including methylparaben)."

BEIJING, July 19 (Xinhuanet) -- Amazon on Monday launched its Kindle textbook rental service, which allows students to rent "tens of thousands of textbooks", according to Los Angeles Times.The e-book textbook rental service will help students save as much as 80 percent on some titles.Amazon said that students can now rent textbooks from 30 to 360 days and can either rent them again or purchase them once the rental period is up."Students tell us that they enjoy the low prices we offer on new and used print textbooks. Now we're excited to offer students an option to rent Kindle textbooks and only pay for the time they need—with savings up to 80 percent off the print list price on a 30-day rental," Dave Limp, vice president of Amazon Kindle said, according to PC Magazine.Rentals can be read on Amazon's Kindle eReaders, and Kindle apps for PCs, as well as smartphones and tablet computers running Apple's iOS, Microsoft Windows Phone 7 and Google's Android operating system.Rentals also have a clear advantage over physical copies that students' notes and highlighted content will be stored in the Amazon Cloud, and can be accessed if students rent the books again or buy at a later time.

来源：资阳报