1.   If the beam is focused on a bleeding vessel or artery, it will cause the blood to coagulate and stop the bleeding.

2.   Knox said the essence of his solution was the magnetic matrix that focuses each beam of electrons.

3.   Joseph Lindmayer, a physicist who specialized in the harnessing of energy from sunlight and focused laser beams, died on Friday at his home in Potomac, Md.

4.   Then they used a scanning electron microscope and focused its beam of electrons down to the width of an atom.