Causal signal transmission by quantum fields. IV: The causal Wick theorem

Wick's theorem in the Schwinger-Perel-Keldysh closed-time-loop formalism is written in a form where the place of contractions is taken by the linear response function of the field. This result demonstrates that the physical information supplied by Wick's theorem for operators is propagation of the free field in space and time.Comment: Final version, to appear in Phys Rev

A Simplified Approach for Recording Neutral Zone

Neutral zone technique is long being used for the management of severely resorbed mandibular ridges. Various materials are used in recording neutral zone, which have their own advantages and disadvantages. This article discusses the use of Polyether impression material which is simpler and more practical