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Logic NAND Gates are available using digital circuits to produce the desired logical
function and is given a symbol whose shape is that of a standard AND gate with a
circle, sometimes called an “inversion bubble” at it’s output to represent
the NOT gate symbol with the logical operation of the NAND gate given as.
SCOPES: BIOLOGICAL LOGIC GATES FOR
BIOLOGICAL COMPUTERS
DNA is often referred to as the building block of life. Now scientists from Imperial
College London have demonstrated that DNA (and bacteria) can be used to create
the fundamental building blocks of a computer - logic gates. Using DNA and
harmless gut bacteria, the scientists have built what they claim are the most
advanced biological logic gates ever created by scientists. The research could lead
to the development of a new generation of microscopic biological computing devices
that, amongst other things, could travel around the body cleaning arteries and
destroying cancers.
While previous research had already proven biological logic gates could be made,
the Imperial College scientists say the big advantage of their creations is that they
behave like their electronic counterparts - replicating the way that electronic logic
gates process information by either switching "on" or "off." Importantly, the new
biological logic gates are also modular, meaning they could be fitted together to
make different types of logic gates and more complex biological processors.
To create a type of logic gate called an "AND gate," the team used modified DNA to
reprogram Escherichia Coli (E.Coli) bacteria to perform the same switching on and
off process as its electronic equivalent when stimulated by chemicals. In a similar
way to the way electronic components are made, the team demonstrated that the
biological gates could be connected together to form more complex components.
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