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Applying Thomson's equations described above to an alpha particle colliding with a gold atom, using the following values: q g = positive charge of the gold atom = 79 q e = 1.26 × 10 −17 C; q a = charge of the alpha particle = 2 q e = 3.20 × 10 −19 C; q e = elementary charge = 1.602 × 10 −19 C; R = radius of the gold atom = 1.44 × 10 ...
The structure of the complex of sodium (Na +) and the antibiotic monensin A Structure of a potassium complex of a crown ether, a synthetic ionophore-ion complex. Biological activities of metal ion-binding compounds can be changed in response to the increment of the metal concentration, and based on the latter compounds can be classified as "metal ionophores", "metal chelators" or "metal ...
Gadolinium has no known native biological role, but its compounds are used as research tools in biomedicine. Gd 3+ compounds are components of MRI contrast agents. [68] It is used in various ion channel electrophysiology experiments to block sodium leak channels and stretch activated ion channels. [69]
Sealing wax was used to close important documents in the Middle Ages. Wax tablets were used as writing surfaces. There were different types of wax in the Middle Ages, namely four kinds of wax (Ragusan, Montenegro, Byzantine, and Bulgarian), "ordinary" waxes from Spain, Poland, and Riga, unrefined waxes and colored waxes (red, white, and green).
Schematic diagram of an ion channel. 1 - channel domains (typically four per channel), 2 - outer vestibule, 3 - selectivity filter, 4 - diameter of selectivity filter, 5 - phosphorylation site, 6 - cell membrane. Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore.
The chemical elements were discovered in identified minerals and with the help of the identified elements the mineral crystal structure could be described. One milestone was the discovery of the geometrical law of crystallization by René Just Haüy , a further development of the work by Nicolas Steno and Jean-Baptiste L. Romé de l'Isle (the ...
In late 1908, Edison had introduced wax cylinders that played for nominally four minutes (instead of the usual two) under the Amberol brand. They were made from a harder (and more fragile) form of wax to withstand the smaller stylus used to play them. The longer playing time was achieved by reducing the groove size and placing them half as far ...
When ion channels are in a 'closed' (non-conducting) state, they are impermeable to ions and do not conduct electrical current. When ion channels are in their open state, they conduct electrical current by allowing specific types of ions to pass through them, and thus, across the plasma membrane of the cell. Gating is the process by which an ...