濮阳东方医院看早泄技术值得信任(濮阳东方看男科技术很专业) (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.

SHANGHAI, Dec. 9 (Xinhua) -- China's homegrown C919 large passenger plane has finished its preliminary development review and entered the development phase, a senior executive of Commercial Aircraft Corporation of China Ltd. (COMAC) in Shanghai said Friday.An expert team of the C919 project has approved the overall preliminary development review (PDR) of the passenger jet, said Jin Zhuanglong, president of the Shanghai-based COMAC.It is expected that the manufacturing process for the components of the prototype will begin by the end of 2011.COMAC signed a deal to sell 20 C919 large passenger planes to China Aircraft Leasing Company Limited (CALC) on Thursday.Up to now, the users of C919 large passenger planes have reached 10 and total orders amount to 215 units.COMAC said earlier it would develop both 168-seat and 156-seat models of the jet, with more models to be developed in the future.It also said that test flights for the single-aisle C919 were scheduled for 2014, and delivery is slated for 2016.

WASHINGTON, Dec. 21 (Xinhua) -- NASA's Dawn spacecraft has sent around 10,000 pictures of the giant asteroid Vesta back to Earth for the first time since its launch in 2007, the U.S. space agency announced Wednesday.The images were taken from an average altitude of 209 km, the closest the spacecraft can get.From the images, scientists could see Vesta's stippled and lumpy surface in great detail, and its many small craters, grooves, and lineaments. The fine scale of the images highlights small outcrops of bright and dark material.With these new discoveries, scientists believe that studying Vesta can help decode the early history of the solar system.Dawn will maintain its low-altitude orbit for another 10 weeks before moving to a higher orbit for another round of photo-taking.Launched in 2007, the 446 million U.S. dollar project aims at studying the chemical composition of Vesta's surface and probing its interior structure.Dawn will leave Vesta in July next year and arrive at the dwarf planet Ceres in February 2015.

ACCRA, Dec. 19 (Xinhua) -- A strange disease has hit inhabitants of the Amansie West District in the Ashanti Region of Ghana, near Kumasi, 270 km north of the capital, claiming two lives, health officials said here on Monday.Director of Public Health Dr. Joseph Amankwa told Xinhua that the disease, which had been identified as Laffa viral hemorrhagic fever, and had symptoms similar to those of malaria, caused victims to bleed to death.Dr. Amankwa said he received information about the infection over the weekend but indicated that no other details were made available."We are sending a team to the affected area to verify what the actual situation is to determine our next action. We are also liaising with the World Health Organization to gather enough data on the infections and soon information will be sent out to the public," he said.According to reports carried by local Joy fm radio station, the disease was the first of its kind in the country.The reports quoted health officials as saying infection was passed on from infected rodents like mice and rats and was highly contagious."About two months ago, a young man of 19 years came to our health center here and complained of malaria, so we treated him for malaria but suddenly, blood started coming from the nose, mouth, anus and the ears, and immediately he died," Municipal Director of Health in the Amansie West District, Dominic Brobbey told the radio station.He warned that although the situation was under control, there were no drugs to treat the disease in Ghana, and therefore urged government to expedite action to acquire the necessary drugs to prevent further deaths.

来源：资阳报