Dr Maryam Zamani holds a phial of blood up to her window overlooking Sloane Street. โItโs beautiful, isnโt it?โ she says. The blood has separated like a B52 cocktail after being โcentrifugedโ, but I suppose itโs beautiful yes, in this blessed SW1 light. Itโs being used for a โmedical-grade facialโ, the details of which I am given in a medical-grade lecture by Dr Zamani, a surgeon, and the kind of person who assumes everyone understands words like โtelangiectasiaโ (thatโs dilatation of the capillaries to you and me).