Stem cells are the primitive master cells found in most tissues that help generate more-specialized cells that perform most functions inside the body.

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And on first examination, it appeared that the adult brain cells had indeed reverted to the less specialized state of the cells placed alongside them.

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Researchers have developed methods of inserting genes to "turn back the clock" on cells that have already specialized, so that they can turn into anything again.

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Nerve cells communicate with one another at specialized points called synapses.

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But producing CIGS cells on a mass scale has turned out to be a formidable technological challenge, requiring the invention of specialized manufacturing equipment.

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