ONE of the world's leading scientists visited the North-East yesterday to see examples of its world-class research.

Professor Bob Grubbs, of the California Institute of Technology, who was awarded a Nobel Prize in December, has collaborated with Dur-ham University chemists for many years.

He has returned to the chemistry department for a week to meet staff and to inaugurate the Frontiers in Science Lecture series.

Work by Durham scientists includes making new molecules and molecular assemblies for applications such as the controlled synthesis of polymers, closely linked to the branch of chemistry that earned Prof Grubbs his prize.

The "Grubbs Reaction", which he devised, is a vital scientific and increasingly commercial step in many chemical processes.

It relates to the manipulation and use of a particular type of molecule, called olefin, where atom groups change places in a reaction.

Related work at Durham is among international research to develop more efficient catalysts.

Head of chemistry Professor David Parker said: "The interest of Prof Bob Grubbs in Durham's work underlines its international significance.

"We are delighted to welcome him back to congratulate him personally on his Nobel Prize, and to show him examples of related ongoing research in Durham."