武清男性龙济专业(天津市龙济男科热线) (今日更新中)

WASHINGTON, Dec. 7 (Xinhua) -- Drugs that affect the levels of an important brain protein involved in learning and memory reverse cellular changes in the brain seen during aging, according to an animal study published Wednesday in the Journal of Neuroscience. The findings could one day aid in the development of new drugs that enhance cognitive function in older adults.Aging-related memory loss is associated with the gradual deterioration of the structure and function of synapses (the connections between brain cells) in brain regions critical to learning and memory, such as the hippocampus.Recent studies suggested that histone acetylation, a chemical process that controls whether genes are turned on, affects this process. Specifically, it affects brain cells' ability to alter the strength and structure of their connections for information storage, a process known as synaptic plasticity, which is a cellular signature of memory.In the current study, Cui-Wei Xie, of the University of California, Los Angeles, and colleagues found that compared with younger rats, hippocampi from older rats have less brain-derived neurotrophic factor (BDNF) -- a protein that promotes synaptic plasticity -- and less histone acetylation of the Bdnf gene. By treating the hippocampal tissue from older animals with a drug that increased histone acetylation, they were able to restore BDNF production and synaptic plasticity to levels found in younger animals."These findings shed light on why synapses become less efficient and more vulnerable to impairment during aging," said Xie, who led the study. "Such knowledge could help develop new drugs for cognitive aging and aging-related neurodegenerative diseases, such as Alzheimer's disease," she added.

BEIJING, Jan. 21 (Xinhua) -- A locomotive producer in central China's Hunan province on Friday rolled out a low-cost magnetically levitated (maglev) train that is more environmental-friendly than conventional ones.The three-carriage train is designed to run at a maximum speed of 100 km per hour and carry 600 passengers, said Xu Zongxiang, general manager of Zhuzhou Electric Locomotive Co. Ltd. of China South Locomotive and Rolling Stock Corporation (CSR). Xu said the new train was much quieter than conventional ones. While a conventional train moves forward by using friction between its wheels and the railway tracks, the maglev train replaces wheels by electromagnets and levitates on the guideway. According to Xu, his company's has minimized the risk of the new maglev train derailing or overturning. "It's ideal for mass transportation, as it is quiet and environmental-friendly. Its manufacturing cost is about 75 percent of a conventional light-rail train," said Xu. The maglev train has a minimum turning radius of 50 meters and can easily run in residential communities or on hilly slopes. "It's an ideal public transport option for Chinese cities and major tourist destinations," said Xu. Railway transport specialist Liu Youmei, also an academician with Chinese Academy of Engineering, said the new train is green, economical and safe. "It can be used for public transport in populous areas and at scenic spots with fragile environments." Liu said China is one of a few countries that have applied maglev technology. Beijing is building a maglev route, the Daitai line (S1), which starts at its IT center in Haidian district, passes through Shijingshan district, and ends in Mentougou district on its western outskirts. The line will be operational next year.The eastern metropolitan of Shanghai runs the world's first commercial maglev system on a 30-km stretch between the downtown business district and Pudong airport. The German-made maglev went into operation on Dec. 31, 2002.

SAN FRANCISCO, Dec. 8 (Xinhua) -- Twitter on Thursday started to roll out a major redesign of its interface in hopes of simplifying users' experience, as well as new brand pages to strengthen its relationship with advertisers.During a press conference at its new headquarters in San Francisco, Twitter Chief Executive Officer Dick Costolo and co- founder Jack Dorsey unveiled a whole new look of the social networking and microblogging service.According to an introduction video, the new homepage features profile on the left and the timeline on the right, which are flipped from the current positions and take less space than they used to.Three new buttons were also introduced as "Home," "Connect" and "Discover." "Connect" shows users who has mentioned them and suggests some accounts they might want to follow. "When you use Discover, you'll see results reflecting your interests -- based on your current location, what you follow and what's happening in the world," said Twitter.The overhauled interface is only available to a small group of users at first and will be rolled out to all users over the coming months. It will also remain consistent across Twitter's official mobile apps. Twitter has launched a page fly.twitter.com to explain all the changes.Along with the introduction of the redesign, Twitter also announced new brand pages on its platform. A total of 21 brand partners will be included in the initial launch, such as American Express, Best Buy, Bing, Coca-Cola, HP, Disney and Nike.Analysts said Twitter has ambitions to compete with similar brand pages from Facebook and Google+. According to eMarketer, Twitter's global advertising revenue is expected to reach 139.5 million U.S. dollars this year and approach 400 million dollars in 2013.

BEIJING, Oct. 29 (Xinhua) -- Chinese Premier Wen Jiabao and Chairman of the Central Military Commission Hu Jintao Saturday issued an order to publicize the Regulations on Resettlement of Ex-Servicemen, which will take effect from Nov. 1.Formulated with an aim to protect the legitimate rights and interests of ex-servicemen, the 53-article document highlights a series of initiatives designed for the appropriate placement of veterans.State organs, social groups, enterprises and public institutions should give preferential treatment to ex-servicemen while recruiting staff members or contract workers, according to the regulations.The regulations provide that demobilized soldiers who register for a civil servant examination or apply for a position in government institutions will be given preference.Those companies or organizations which recruit retired soldiers will enjoy favorable policies prescribed by current laws and regulations.

BERLIN, Jan. 17 (Xinhua) -- Researchers in Germany have found a cheap and easy way to synthesize anti-malaria drug in large quantities from waste materials, said the Max Planck Society on Tuesday.Currently there are nearly one million people die worldwide each year due to lack of effective drugs, as sweet wormwood, from which artemisinin, the effective essence to fight malaria can be extracted, only grows in China, Vietnam and a few other countries.However, researchers in Germany have now developed a simple process for the synthesis of artemisinin in laboratory, using artemisinic acid, a substance contained in the by-product, or waste materials of the isolation of artemisinin from sweet wormwoods, as row materials of synthesizing artemisinin."The production of the drug is therefore no longer dependent on obtaining the active ingredient from plants," said Peter Seeberger, director at the Max Planck Institute of Colloids and Interfaces in Potsdam and professor at Free University of Berlin.The artemisinic acid in the waste material boasts a volume 10 times greater than the active ingredient itself, said Seeberger, and they could be turned into artemisinin in four and a half minutes in a so-called continuous-flow reactor.Seeberger estimated that 800 of the reactors would be enough to cover the global requirement for artemisinin, and the whole innovative synthesis process could be ready for technical use in three to six months.Malaria is a disease caused by parasites that are transmitted to people through the bites of infected mosquitoes. In 2010, malaria caused an estimated 655,000 deaths, mostly among African children.

来源：资阳报