Protonation safety

Nuclear reactions are excited when projectile energies are typically in the MeV range. Medium size ion-accelerators are, therefore, necessary to obtain these projectile energies. Protons and a projectiles, typical projectiles in other ion-beam analysis techniques as RBS or PIXE, have few useful nuclear reactions. Deuteron beams excite many more nuclear reactions, but the use of deuteron beams instead of standard beams is more hazardous, because of efficient neutron production. Strict safety rules are necessary when high-energy deuteron beams are used. 

The electrocatalytic oxidation of methanol has been widely investigated for exploitation in the so-called direct methanol fuel cell (DMFC). The most likely type of DMFC to be commercialized in the near future seems to be the polymer electrolyte membrane DMFC using proton exchange membrane, a special form of low-temperature fuel cell based on PEM technology. In this cell, methanol (a liquid fuel available at low cost, easily handled, stored, and transported) is dissolved in an acid electrolyte and burned directly by air to carbon dioxide. The prominence of the DMFCs with respect to safety, simple device fabrication, and low cost has rendered them promising candidates for applications ranging from portable power sources to secondary cells for prospective electric vehicles. Notwithstanding, DMFCs were... 

Other agents that appear to be safe for use in pregnancy include the proton pump inhibitors, sucralfate, and meto-clopromide (Table 44-5). The proton pump inhibitor with the largest body of human safety data during pregnancy is omeprazole.24... 

Ford Motor Co., Direct-hydrogen-fueled proton-exchange membrane fuel ceU system for transportation applications hydrogen vehicle safety report, D.T. Inc., ed., Arlington,VA (1997). 

Since their introduction in the late 1980s, these efficacious acid inhibitory agents have assumed the major role for the treatment of acid-peptic disorders. Proton pump inhibitors (PPIs) are now among the most widely prescribed drugs worldwide due to their outstanding efficacy and safety. 

Proton pump inhibitors are extremely safe. Diarrhea, headache, and abdominal pain are reported in 1-5% of patients, although the frequency of these events is only slightly increased compared with placebo. Proton pump inhibitors do not have teratogenicity in animal models however, safety during pregnancy has not been established. 

H2-receptor antagonists continue to be prescribed commonly. However, due to their superior acid inhibition and safety profile, proton pump inhibitors (see below) are steadily replacing H2 antagonists for most clinical indications. 

Note Moderately polar solvent, ethereal odor soluble in water and most organic solvents flammable moderately toxic incompatible with strong oxidizers can form potentially explosive peroxides upon long standing in air see the relevant tables in the chapter on laboratory safety commercially, it is often stabilized against peroxidation with 0.5 to 1.0% (mass/mass) p-cresol, 05 to 1.0% (mass/mass) hydroquinone, or 0.01% (mass/mass) 4,4 -thiobis(6-ferf-butyl-m-cresol) can polymerize in the presence of cationic initiators such as Lewis acids or strong proton acids. Synonyms THF, tet-ramethylene oxide, diethylene oxide, 1,4-epoxybutane, oxolane, oxacyclopentane. 

So, where is the safety catch The important point about Fmoc is that is has a rather acidic proton (p Ca about 25), shown in black. The proton is the Achilles heel treatment of Fmoc-protected amines with base eliminates a fulvene to reveal the NH2 group. 

Thomas, C.E. Direct-Hydrogen-Fueled Proton-Exchange Membrane Fuel Cell System for Transportation Applications Hydrogen Vehicle Safety Report, DOE/CE/5039-502. U.S. Department of Energy, Washington, D.C. 1997. 

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