Ventilators for Coronavirus: What Are They, How They Work, and When to Use Them VAP risk index: Early prediction and hospital phenotyping of ventilator associated pneumonia using machine learning ScienceDirect Why Does Vape Juice Turn Brown? How Long Vape Juice Lasts & How to Make It Last Longer E Cigarette Direct Is this a problem with my pod? My juice keeps going dark really quickly and it tastes horrible. I know it can go brown through oxidation but I've read that shouldn't affect