Lead With a Poisonous Electron Shield
...nt role in regulating and transporting the calcium cation in the human body. A calcium ion binds to seven ligands at the active centers of the enzyme. If one of the four possible calcium ions of calmodulin is replaced by lead, the lead ion remains roughly heptacoordinated, but this active center becomes dis...Quick and Inexpensive DNA Testing
...e electric charge will attract positive charges, a cation with a positive charge will attract negative charges. Single-stranded DNA adsorbs on negatively charged citrate ions on the gold nanoparticles while double-stranded DNA does not. Given that both single-stranded and double-stranded DNA are (nominally)......covered. The species - pentamethylcyclopentadienyl cation (a positively charged ion) - was thought not to ex...and graduate student Lijun Lin discovered that the cation is stable in the solid state for weeks at room temperature and in solution. The cyclopentadienyl c...