Abstract: For use in a spectrophotometry or spectrofluorimetry system, where a fluid to be analyzed, is passed into or through a tube having at least one branch, a plastic device insertable into said branch, said device comprising a tubular plastic member the inner end of which is closed by a transparent transverse end wall, extending into the tube branch and within which an end of a fiber optic cable is removably secured with such end disposed in facing engagement with the inside of said wall, and a detector cap defining a chamber to hold some of the fluid or a dye color reactive to such fluid, is secured on the opposite side of the end wall. The tubular plastic member is removably securable in, and closes the tube branch.

Abstract: An orthodontic bracket assembly is adapted for use with an arch wire in straightening a tooth having a crown long axis preferrably disposed at a particular angle with respect to an occlusal plane. The bracket assembly includes a base for fixing the assembly to the tooth and at least one tie wing having a fixed relationship with the base. The tie wing has a facial surface defined by a mesial edge, a distal edge, a gingival edge and an occlusal edge. At least one of the gingival edge and the occlusal edge are disposed at the particular angle with respect to at least one of the mesial edge and the distal edge of the tie wing, so that the facial surface of the tie wing has a generally rhomboidal configuration. This facilitates alignment of the assembly with respect to the occlusal plane and the crown long axis of the tooth.