A power supply for “triggerless,” repetitively pulsed cathodic arcs has been developed. It is based on a thyristor-switched, high-voltage, high-current, pulse-forming network (PFN). It can provide high pulsed currents (up to 2 kA), with duration of 600 μs, and pulse repetition rate of up to 10 Hz. Higher repetition rates are possible at lower current. The rectangular pulse shape and amplitude are reproducible to within a few percent. Cathodic arc initiation is extremely reliable because the charging voltage is much higher than the minimum starting voltage for the triggerless arc initiation method. The energy utilization efficiency is very high by intentionally mismatching load and PFN impedances and by using an efficiency-enhancing diode; the stored energy is dissipated primarily in the arc.

were subjected to biochemical analysis and to detailed immunochemical analysis with rabbit anti-PEV immunoglobulins. The results of chemical analysis, of analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis performed in coajunction with silver staining, and of analysis by crossed immunoelectrophoresis, sodium dodecyl sulfate-polyacrylamide gel-crossed immunoelectrophoresis, and Western blotting showed clearly that lipopolysaccharide was a major constituent of each monovalent extract and that it was probably the dominant antigen present in at least 15 of the 16 monovalent extracts. A 16.2-kilodalton protein, which was pronase resistant and nonsedimentable at 105,000 x g and which appeared to be biochemically and antigenically unrelated to pili, was a common although minor antigen for all extracts. Several other proteins, some of outer membrane origin, were also detected in unformalinized extracts, but these were also minor antigenic constituents of the vaccine. Neither pilin nor flagellin appeared to be major protein constituents of tested monovalent extracts, although anti-flagella antibodies could be demonstrated in rabbit anti-PEV by Western blotting. Preliminary analysis by crossed immunoelectrophoresis of serum raised in volunteers to PEV also indicated the presence therein of antibodies to lipopolysaccharide antigens.

Purified anti-DNP antibody was obtained from a pool of hyperimmune mouse sera. Purity was verified by radioimmunoelectrophoresis, disc gel electrophoresis and sedimentation equilibrium studies. A molecular weight of 141,500 was determined by the method of Yphantis. A corrected valence of 2 and an average intrinsic association constant of 6 × 105 liters/mol was measured by equilibrium dialysis. The purified antibody elicited a positive PCA reaction in mice only after a 3-hr incubation period. The length of the incubation period, the electrophoretic mobility and the heat stability at 56°C indicated that this antibody belonged to the 7S γ1 class of mouse immunoglobulin.