Watching it filter through the glass skyscrapers, I feel I am entering a forest of mirrors, struggling to recognise anything of the city I last visited 15 years ago.

BBC: A Beijing state of mind

The material to be tested is liquefied and passed through a filter made up of glass beads which are coated with the antibodies.

BBC: Speedy 'burger bug' test

The challenge now: a broadly weaker economy that is hurting everything from sales of fiber-optic glass to the filter technology Corning manufactures for diesel automobiles, a business hurt by the popularity of diesel engines in Europe.

FORBES: Corning Q2 Earnings Drop 39% On Falling LCD Sales [Updated]