Versatile, high-speed force transducer using a laser diode beam as an optical lever.

A force transducer with variable sensitivity and speed is described. Its moving element is a cantilever beam that projects vertically into a muscle bath. A brace constrains bending of the beam to a short, proximal "hinge.

Three dimensional structure of human fibrinogen under aqueous conditions visualized by atomic force microscopy.

Fibrinogen plays a central role in surface-induced thrombosis. However, the interactions of fibrinogen with different substrata remain poorly understood because of the difficulties involved in imaging globular proteins under aqueous conditions. We present detailed three dimensional molecular scale images of fibrinogen molecules on a hydrophobic surface under aqueous conditions obtained by atomic force microscopy.

The morbidity of vasectomy.

Elective bilateral vasectomy has become an established surgical procedure to achieve sterilization in the male. The ability to accomplish this by an ambulatory technique, with few side-effects, probably accounts for the widespread demand by the general public. However, a number of significant complications were encountered in a series of 250 patients who were carefully surveyed to determine the actual morbidity of this operation.