E-cigarettes: still many questions.
D055615:Electrical Equipment and Supplies / Q000009:adverse effects; D033161:Government Regulation; D006801:Humans; D009538:Nicotine / Q000008:administration & dosage / Q000009:adverse effects; D016540:Smoking Cessation / Q000379:methods; D062789:Tobacco Products / Q000009:adverse effects* / Q000191:economics; D061485:Tobacco Use Cessation Devices / Q000009:adverse effects; D014481:United States
D009538:Nicotine