Controlled trial evaluation of exposure duration to negative air ions for the treatment of seasonal affective disorder.

This study evaluated the effectiveness of 30 or 60min of daily exposure to high-density or to zero-density (placebo condition) negative air ions over 18 days on the symptoms of seasonal affective disorder (SAD) in 40 participants under controlled laboratory conditions. Exposure to high-density negative air ions was superior to zero-density negative air ions in alleviating depression and the atypical symptoms of SAD. Also, more subjects in the high-density negative air ions groups met two different clinical response criteria than did those in the zero-density groups.

A randomized, placebo-controlled trial of bright light and high-density negative air ions for treatment of Seasonal Affective Disorder.

This study, conducted over the course of 5 years, assessed the antidepressant efficacy of two active treatments, bright white light and high-density negative ions, and the efficacy of two placebo treatments, dim red light and low-density negative ions, for Seasonal Affective Disorder (SAD). In a controlled laboratory setting, 73 women with SAD were exposed to one of the four treatment conditions over 12 consecutive days. Pretreatment expectation ratings did not significantly differ among the four treatment groups; however, expectation scores and treatment benefits were positively related.

Biomechanical evaluation of injury severity associated with patient falls from bed.

This study investigated the severity of injuries associated with falling from bed and the effectiveness of injury-prevention strategies. Injury criteria were calculated for head- and feet-first falls from six bed heights onto a tiled surface and floor mat. These values indicated a 25% chance of experiencing a serious head injury as a result of falling feet-first from a bed height of 97.

Metallurgical, surface, and corrosion analysis of Ni-Cr dental casting alloys before and after porcelain firing.

Objectives: A porcelain veneer is often fired on nickel-chromium casting alloys used in dental restorations for aesthetic purposes. The porcelain-fused-to-metal (PFM) process brings the temperature to over 950 degrees C and may change the alloy's corrosion properties. In this study, the metallurgical, surface, and corrosion properties of two Ni-Cr alloys were examined, before and after PFM firing.