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Local cooling has been shown to have the potential to adjust human thermal comfort. Previous studies on local cooling are mainly conducted with subjects in sitting posture. When in a sleeping posture, the distribution of blood flow and the contact area between human body and the environment are different. In this study, the effects of local cooling on thermal comfort were investigated when people in a sleeping posture in a 30℃ environment. Thirty-six healthy adults participated into this experiment. Local cooling was applied to five parts, including the head-and-neck part, chest-and-abdomen part, upper arm, back and thigh, each for 10 min. The cooling conditions were separated by 30 min of ‘no-cooling’. Thermal sensation and thermal comfort were evaluated with visual analog scales. Physiological parameter (skin temperature) was measured during the exposure. The results show that: when people in sleeping posture, local cooling of the back is an effective way to improve thermal sensation and thermal comfort. Thus back is recommended to be selected as the exposure part when the effect of local conductive cooling on sleep quality and thermal comfort in a hot environment are studied. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the effects of negative oxygen ions on sleep quality. An experiment was held using both subjective and physiological methods on 33 subjects (16 females and 17 males). The subjective assessment on sleep quality was surveyed and the duration of every sleep stage was determined. The results of this experiment indicate that the negative oxygen ions have a significant effect on sleep quality. The subjective results indicate that with negative oxygen ions subjects fell asleep easier, meanwhile, the objective results indicate that the duration of sleep onset latency was shortened and the slow-wave sleep was lengthened. All these results show that negative oxygen ions can improve people’s sleep quality. [ABSTRACT FROM AUTHOR]

Vinyl-functionalized hyperbranched polymers (HBPs) have attracted much attraction because their pendant vinyl groups can be further modified for a required application. However, the syntheses of these polymers are difficult, because the cross-linking is inevitable during the polymerization reaction. The present work reports a new, facile, one-step strategy for the synthesis of vinyl-functionalized HBPs v ia the self-condensing anionic copolymerization of commercially available allyl methacrylate and hydroxyethyl methacrylate with a monomer conversion approaching 100% at room temperature. The hyperbranched structures were confirmed by triple-detection size exclusion chromatography. The pendent vinyl groups of the resulting polymer were successfully modified by a “thiol-ene” reaction. This method provides a facile approach for preparing vinyl-functionalized HBPs with excellent monomer conversions under mild conditions, and will be useful in materials chemistry. [ABSTRACT FROM AUTHOR]