济南阳痿怎么样能治(济南龟头敏感阳痿怎么治) (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.

HELSINKI, Aug. 21 (Xinhua) -- The Finnish company Spektikor has recently developed a novel type of disposable heart rate indicator, local media reported on Sunday.Different from a conventional heart rate monitor, it is a speed heart rate indicator designed for first aid professionals and specially used in first aids in major accidents, disasters and other crises.According to Spektikor, the product is consisted of a heart rate sensor with two EKG electrodes and a LED indicator, which are connected by a 35-cm-long wire.In operation, the sensor is placed on a patient's chest and the LED indicator is sticked to the patient's cheek. If the heart rate is within the normal range, the LED indicator will flash green with each beat. If the heart rate is dangerously low or high, the light will turn red.The product will help hospital staff speed up their work considerably as it is not necessary to check the pulse manually. In addition to saving time, it will also enhance safety, as the LED indicator can be seen clearly at a glance.The market prospect of the disposable heart rate indicator is quite optimistic as there is a worldwide need for the product.

SAN FRANCISCO, June 14 (Xinhua) -- Apple updated its online store on Tuesday to begin offering unlocked models of iPhone 4 in the United States for the first time."The unlocked iPhone 4 requires an active micro-SIM card that you obtain from a supported GSM wireless carrier," said Apple in the product description. The iPhone requires a smaller version of the standard SIM (Subscriber Identity Module) card.Started at 649 U.S. dollars for the 16 GB version, the unlocked model is a GSM phone, which means, in the United States, the phone runs on networks of T-Mobile or AT&T, although it can only send data over T-Mobile's old EDGE network, not its 3G network and the faster HSPA+ network.Verizon and Sprint, the other two major U.S. wireless carriers, both use CDMA networks that do not use SIM cards.The iPhone 4 has been sold unlocked in other countries. For frequent international travelers, an unlocked iPhone means they just need to pop in a micro-SIM card for whichever country they are going, avoiding provider's high international fees.According to Apple, iPhone sales grew 113 percent year over year in the second quarter of its fiscal 2011, reaching a record high of 18.65 million units.

SAN FRANCISCO, July 6 (Xinhua) -- Facebook on Wednesday introduced a new video calling feature powered by Skype and some improvements to the chat designs on the social networking site.According to Facebook, users can reach video calling from a new "Call" button on a friend's profile or from the chat panel after downloading a Skype application. A recipient will receive an alert that they are being called and can then accept or decline.At the press event held at Facebook headquarters in Palo Alto, California, CEO Mark Zuckerberg said the feature will begin with one-on-one video chat. Skype CEO Tony Bates, whose company has been acquired by Microsoft, said Skype is considering having its paid product within the Facebook product.The social networking company also introduced "Ad Hoc Group Chat", which enables users to start a group chat instantly without creating a group with those multiple friends at first. The new group chat feature is also available for Facebook's mobile interfaces.Facebook also introduces a sidebar that lists the people a user messages most, enabling users to chat with close friends, professional contacts or co-workers without being interrupted. The sidebar can adjust with the size of users' browser window and automatically appears when the window is wide enough.In the opening remarks at the press event, Zuckerberg confirmed that Facebook had surpassed 750 million monthly active users. He said the company had declined to announce the number earlier because it has become focused on other metrics, like how actively users are sharing information.The CEO said users are now sharing 4 billion "things" on Facebook every day, which grew at an exponential rate compared to the amount users share a year ago."Social networking is at an inflection point," said Zuckerberg, adding that he believes social networking now is more about the strength of connecting people rather than the quantity of users or ubiquity of the technology.Zuckerberg presented a graph to show how Facebook product launches have helped drive the growth of sharing. He said the social network expects more innovations from other companies involved in everything from music to communication to help drive the growth.

来源：资阳报