Much as markings delineate a topographic map, a series of lines meander around groups of ions
MacKinnon later identified the structure of a channel that regulates the flow of chlorine ions
Most scientists had thought that the voltage-sensing regions of the pore would be hidden within the ion
channel, but instead they jut out as hinged projections that MacKinnon calls "paddles" In hindsight, he adds, it's clear that the free-moving nature of these four, positively charged paddles accounts, at least in part, for the difficulties in crystallizing the pores.
However, he says, the researchers' calculations consider only 32 water molecules around each ion
and don't include an energy barrier that water molecules must overcome as they change their structure and permit passage of the ions
These snapshots provided immediate insight into questions such as how the channel can shuttle up to 100 million potassium ions
across a cell membrane in a single second while keeping out similarly charged sodium ions
, whose smaller size would seem to make passage even easier.
Turco and his coworkers suggest that ions
created by cosmic rays form the nucleus of many aerosol particles.
But this recent re-branding announcement requires that Positive Ions
make some public statement to reassure its existing users and advertisers that it is still pursuing its rights in Court.
The researchers used a combination of magnetic and electric fields to trap the million beryllium ions
at a temperature of less than 10 millikelvins.
Normally, each ion
in the row oscillates about an equilibrium position, and repulsive electric forces between adjacent ions
induce a collective motion shared by all the ions
Scientists had not known, however, where on the crocodile hemoglobin's amino acid chains the bicarbonate ions
More-over, because ions
stored in SuperEBIT are practically stationary, researchers also avoid having to correct for relativistic effects caused by the motion of ions
at close to the speed of light.
Moreover, nudging the ions
closer together increased the spacing of the patterns fringes.