Category: Lead
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Silicene is a two-dimensional allotrope of silicon, with a hexagonal honeycomb structure similar to that of graphene
Contrary to graphene, silicene is not flat, but has a periodically buckled topology; the coupling between layers in silicene is much stronger than in multilayered graphene; and the oxidized form of silicene, 2D silica, has a very different chemical structure from graphene oxide. History Although theorists had speculated about the existence and possible properties of free-standing silicene, researchers…
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Zinc, maybe
No proof for the need of zinc in human cells was shown until the late 1930s. More than most ever wanted to know about zinc. A work in progress.
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In Chinese alchemy, elixir poisoning refers to the toxic effects from elixirs of immortality that contained metals and minerals such as mercury and arsenic
In Chinese alchemy, elixir poisoning refers to the toxic effects from elixirs of immortality that contained metals and minerals such as mercury and arsenic. The official Twenty-Four Histories record numerous Chinese emperors, nobles, and officials who died from taking elixirs to prolong their lifespans. The first emperor to die from elixir poisoning was likely Qin Shi Huang (d. 210 BCE) and the last was the Yongzheng Emperor (d. 1735 CE). Despite common knowledge…
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Ferrochelatase catalyses the eighth and terminal step in the biosynthesis of heme, converting protoporphyrin IX into heme B
Protoporphyrin ferrochelatase (EC 4.98.1.1, formerly EC 4.99.1.1, or ferrochelatase; systematic name protoheme ferro-lyase (protoporphyrin-forming)) is an enzyme encoded by the FECH gene in humans. Ferrochelatase catalyses the eighth and terminal step in the biosynthesis of heme, converting protoporphyrin IX into heme B. It catalyses the reaction: protoheme + 2 H+ = protoporphyrin + Fe2+ Function Ferrochelatase catalyzes the insertion of ferrous iron into protoporphyrin IX in the heme biosynthesis…