When humans have a heart attack, heart muscles die after being cut off from their blood supply. But what if the heart could grow new muscle to replace the dead tissue? Some amphibians can regrow body parts, even entire limbs. But humans and other hig

发表于:2018-12-16 / 阅读(215) / 评论(0) 分类 VOA标准英语2011年(三月)

Grammar Girl here. Today's topic is semicolons. I get questions about semicolons a lot, so it's time to clear up some confusion. Semicolons separate things. Most commonly, they separate two main clauses that are closely related to each other but that

发表于:2019-01-02 / 阅读(48) / 评论(0) 分类 英语语法 Grammar Girl

Grammar Girl here. Surprise! You get a bonus show today because Thursday is National Punctuation Day and I'm going to have a slightly different kind of podcast to celebrate. Today's topic is semicolons. I get a lot of questions about semicolons, so i

发表于:2019-01-02 / 阅读(46) / 评论(0) 分类 英语语法 Grammar Girl

Scientists Regrow Tissue Killed During Heart Attack U.S. scientists have done what was once considered science fiction - regrown heart muscle to replace tissue that was killed off in a heart attack. It's the latest advance in the field of regenerativ

发表于:2019-01-14 / 阅读(54) / 评论(0) 分类 VOA标准英语2012年(二月)

Researchers have identified a link between dementia and the brain damage that can occur in older people with high blood pressure and other forms of cardiovascular disease. High blood pressure, high cholesterol, and other conditions that affect blood

发表于:2019-01-14 / 阅读(69) / 评论(0) 分类 VOA标准英语2010年(十一)月

Beating Heart Tissue from Stem Cells In a study in the journal Science, researchers explain how they used mouse embryonic stem cells and microchip technology to create heart muscle tissue that actually beats. Cynthia Graber reports One of the goals o

发表于:2019-01-30 / 阅读(82) / 评论(0) 分类 60秒科学