Smokeless tobacco (ST) delivers nicotine in doses similar to those received in cigarette smoking but does not expose the user to the toxic combustion gases and particles that are responsible for most tobacco-induced disease. This Opinion piece discusses the controversies pertaining to ST and health, the pros and cons of ST in harm reduction, and progress in treatment for those who would like to...

tial for posterior dislocation of the donor corneal disc in aphakic eyes must be taken into consideration. Longer-lasting, higher-buoyancy gases (such as SF6) could be used as alternatives to air, but the possible toxic effect to endothelial cells should be elucidated. Correspondence: Dr Yoo, Cornea and External Diseases, Bascom Palmer Eye Institute, 900 NW 17th St, Miami, FL 33136 (syoo@med .m...

The first example of a mixed-metal amidoborane Na(2)Mg(NH(2)BH(3))(4) has been successfully synthesized. It forms an ordered arrangement in cation coordinations, i.e., Mg(2+) bonds solely to N(-) and Na(+) coordinates only with BH(3). Compared to ammonia borane and monometallic amidoboranes, Na(2)Mg(NH(2)BH(3))(4) can release 8.4 wt% pure hydrogen with significantly less toxic gases.

Introduction: Chemical weapons , which their history dates back to the first world war , refer to any factor that has direct toxic effects on human being , animals and plants. Iraqi regime used chemical weapons and various poisons during the imposed war against Iran of which mustard and nervous gases are examples that their effects are seen in victims even after passing many years. Materials a...