healthcare, and domestic application: for example, infusing clothing with nanosilver particles thus allows them to stay odourless for longer. Bacteria can, however, develop resistance to the antimicrobial action of silver. Silver compounds are taken up by the body like mercury compounds, but lack the toxicity of the latter. Silver and its alloys are used in cranial surgery to replace bone, and silver–tin–mercury amalgams are used in dentistry. Silver diammine fluoride, the fluoride salt of a coordination complex with the formula [Ag(NH3)2]F, is a topical medicament (drug) used to treat and prevent dental caries (cavities) and relieve dentinal hypersensitivity. Electronics Silver is very important in electronics for conductors and electrodes on account of its high electrical conductivity even when tarnished. Bulk silver and silver foils were used to make vacuum tubes, and continue to be used today in the manufacture of semiconductor devices, circuits, and their components. For example, silver is used in high quality connectors for RF, VHF, and higher frequencies, particularly in tuned circuits such as cavity filters where conductors cannot be scaled by more than 6%. Printed circuits and RFID antennas are made with silver paints, Powdered silver and its alloys are used in paste preparations for conductor layers and electrodes, ceramic capacitors, and other ceramic components. Brazing alloys Silver-containing brazing alloys are used for brazing metallic materials, mostly cobalt, nickel, and copper-based alloys, tool steels, and precious metals. The basic components are silver and copper, with other elements selected according to the specific application desired: examples include zinc, tin, cadmium, palladium, manganese, and phosphorus. Silver provides increased workability and corrosion resistance during usage. Chemical equipment Silver is useful in the manufacture of chemical equipment on account of its low chemical reactivity, high thermal conductivity, and being easily workable. Silver crucibles (alloyed with 0.15% nickel to avoid recrystallisation of the metal at red heat) are used for carrying out alkaline fusion. Copper and silver are also used when doing chemistry with fluorine. Equipment made to work at high temperatures is often silver-plated. Silver and its alloys with gold are used as wire or ring seals for oxygen compressors and vacuum equipment. Catalysis Silver metal is a good catalyst for oxidation reactions; in fact it is somewhat too good for most purposes, as finely divided silver tends to result in complete oxidation of organic substances to carbon dioxide and water, and hence coarser-grained silver tends to be used instead.