This essentially allows particles of varying sizes, including large plasma proteins, to easily enter the brain with little to no regulation.

The Earth's magnetopause has been compared to a sieve, as it allows particles from the solar wind to enter.

The pulsed stasis field allowed enough particles to escape to induce a short-term vision.

That could allow radioactive particles to escape, possibly contaminating the local water supplies.

Most particles have unique combinations of signals left in each detector sub-system, allowing different particles to be identified.

The uncertainty principle would allow particles and radiation to leak out of the black hole at a steady rate.

This allowed more stable particles and photons to form.

The lower-density martian atmosphere allows much larger particles than on earth to survive the passage through to the surface, largely unaltered until impact.

When used for cleaning, soap allows otherwise insoluble particles to become soluble in water and then be rinsed away.

Which means that any combination of electric () and magnetic () fields will allow charged particles with only velocity through.