教育学习   常速英语

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VEGF stands for vascular endothelial growth factor. It's a fancy name for a kind of growth hormone that is a growth factor for blood vessel cells. Blood vessel cells have receptors for th...

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Bacteria doubles. Two goes to four, goes to eight, goes to 16, goes to 32. And in 24 hours, we have 2 to the 72 microbes sitting there. They obviously have the capacity to divide very, ver...

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So this is HIV. It's a typical retrovirus, meaning that it has an outer envelope. And in the center, it has two copies of RNA, as well as an enzyme, here in blue. That's reverse tran...

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We're going to first look at the right ventricle atrium connection in which cells are being brought out of the low-oxygen starved body and being pumped into the lungs. And if we look at...

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Let's review how HIV's reverse transcriptase works. The yellow strand is HIV RNA; it's attached to the reverse transcriptase enzyme. Reverse transcriptase uses the hosts cell nucleotides....

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So when HIV buds from a cell, it's not in a mature form. Its proteins are actually in a multilinked chain, so protease comes in and cleaves the proteins, in several different places. So...

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This video was prepared by my colleagues Dieter Egli and Kevin Eggan. And you see here, on the left is what's called a holding pipette, which gently sucks on the egg. The egg is surroun...

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One of the most intriguing uses of stem cells can be found in the field of regeneration. Whether the goal is to regenerate damaged heart or nerve cells or to regenerate an entire limb, ...