�u�r-�bacteria, DNA helix, neuron synapse, helicopter blade, microchip transistor, virus capsid, protein molecule, circuit board trace, aircraft wing spar, nuclear reactor core, cytoplasmic vesicle, atomic nucleus, engine cylinder head, mitochondrial membrane, rocket nozzle, computer motherboard, cell wall, satellite dish antenna, vaccine nanoparticle, electric motor coil, blood clot fibrin fiber, transistor gate, cytoplasmic inclusion body, jet engine turbine blade