PROFESSOR STEFAN HELL (CHEMISTRY, 2014)

Scientist Stefan Hell, 52, a director at the Max Planck Institute for Biophysical Chemistry in Gottingen, Germany, together with two American researchers, won the Nobel Prize for Chemistry last year for using fluorescence - a phenomenon in which certain substances become luminous after having been exposed to light - to make microscopes more powerful than before, enabling deeper insight into cells.

PROFESSOR JAMES MIRRLEES (ECONOMIC SCIENCES, 1996)

Economist James Mirrlees, 79, of Scotland, received the Nobel Memorial Prize in Economic Sciences in 1996 for his theory of optimal income taxation, which allowed optimal tax schedules to be calculated using realistic economic models.

PROFESSOR HAROLD KROTO (CHEMISTRY, 1996)

The English chemist shared the 1996 Nobel Prize in Chemistry for the discovery of fullerenes - nanometre-scale carbon structures with remarkable properties and many potential applications. Sir Harold, 76, is currently carrying out research in nanoscience and cluster chemistry as well as developing new Internet approaches to educational outreach.

PROFESSOR WOLE SOYINKA (LITERATURE, 1986)

Nigerian playwright, novelist and poet Wole Soyinka won the Nobel Prize for Literature in 1986. The 81-year-old, who continues to lecture extensively in Nigeria and around the world, is the first African to be honoured in that category.

PROFESSOR ADA YONATH (CHEMISTRY, 2009)

Professor Ada Yonath, 76, a director at the Weizmann Institute of Science in Israel, won the Nobel Prize for Chemistry in 2009 for her work with ribosomes. She is one of a handful of women who have won the prize in chemistry.