Closed reduction of dislocations of the lower cervical spine

Dislocation of the lower cervical spine (C3-T1) is associated with a high incidence of neurologic injury. Attempted closed reduction by skeletal traction with weights ranging up to 50 lb (23 kg) is considered standard care in North America, although these attempts are often unsuccessful. This retrospective review, over a 6-year span, of 39 patients with dislocations and facet locks of the lower cervical spine treated with closed reduction showed that 35 (90%) were successful. Recommended weight was exceeded in 22 patients (63%) with no deteriorations in neurologic status. If patients are monitored radiologically and neurologically throughout traction, up to 70% of body weight can be used safely. An algorithm for treatment is provided.

Gas Chromatographic-Thermal Energy Analysis Method for iV-Nitrosodibutylamine in Latex Infant Pacifiers: Collaborative Study

Each of 5 collaborating laboratories determined volatile N-nitrosamines in 3 blind quadruplicate sets of latex rubber infant pacifier samples, using a gas chromatographic-thermal energy analysis (GCTEA) method. Volatile N-nitrosamines are extracted from cut-up pacifier nipples with CH2C12. The extract is concentrated and subjected to high temperature purge and trap, and the nitrosamines are eluted from the trap and determined by GC-TEA. N-Nitrosodibutylamine (NDBA) was the only nitrosamine found in sufficient concentration to allow analysis. NDBA concentrations of the 3 sets of samples were 82.6,21.0, and 7.12 ng/g rubber. The repeatability relative standard deviations ranged from 7.46 to 24.0% and the reproducibility relative standard deviations from 7.46 to 29.2%. The minimum detectable level of NDBA by this method is 3.6 ng/g rubber. The method has been adopted official first action.

Uniform illumination of large targets using a lens array

Inserting an array of nearly 100 similar lenses into a common focal system, the uniformity of the illumination of a target can evidently be improved without being affected by the near-field distribution of laser beams. We report here geometrical- and physical-optics analyses of the lens array and compare them with the experimental results.