Other subjects explored include hydrogen bonding effects on the photochemistry of chromophores in solution, photochemical generation of silicon-centered radicals and their reactions, and photochemical processes at the air-water interface of atmospheric droplets.
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class of psychoactive drugs. It is the world's most widely consumed psychoactive drug, but unlike many other psychoactive substances, it is legal and unregulated in nearly all parts of the world.
Viagra is one of a class of drugs known as PDE-5 (Phosphodiesterase type 5) inhibitors. Viagra and the other PDE-5 inhibitors can help men with erectile dysfunction (male impotence) by enhancing the erectile response when a man is sexually stimulated.Aside from Viagra, the other drugs in this class are Cialis (Tadalafil) and Levitra (Vardenafil).iagra and the other PDE-5 inhibitors can help men with erectile dysfunction (male impotence) by enhancing the erectile response when a man is sexually stimulated. Aside from Viagra, the other drugs in this class are Cialis (Tadalafil) and Levitra (Vardenafil).