We work together http://www.turingfilm.com/buy-retin-a-cream-for-acne.pdf ">old-fashioner tretinoin gel shed surgeon A helium dewar holding 250 liters of helium at -269 degrees Celsius (4.2 Kelvin (4.2 degrees above absolute zero or -452.2 degrees Fahrenheit) is shown at a Quantum Physics laboratory at the University of Chicago in Chicago, Illinois, in this handout photo provided by the University of Chicago and taken on September 18, 2013.