RESUMO
We report unique conductive leaf-inspired (in particular, stomata-inspired) supramolecular gas sensors in which acetylated cyclodextrin derivatives rule the electric output. The gas sensors consist of polymers bearing acetylated cyclodextrin, adamantane, and carbon black. Host-guest complexes between acetylated cyclodextrin and adamantane corresponding to the closed stomata realize a flexible polymeric matrix. Effective recombination of the cross-links contributes to the robustness. As gas sensors, the supramolecular materials detect ammonia as well as various other gases at 1 ppm in 10 min. The free acetylated cyclodextrin corresponding to open stomata recognized the guest gases to alter the electric resistivity. Interestingly, the conductive device failed to detect ammonia gases at all without acetylated cyclodextrin. The molecular recognition was studied by molecular dynamics simulations. The gas molecules existed stably in the cavity of free acetylated cyclodextrin. These findings show the potential for developing wearable gas sensors.
RESUMO
INTRODUCTION: The aim of this study was to determine the effectiveness of prune juice on chronic constipation. METHODS: We conducted a double-blind, randomized, placebo-controlled trial in Japanese subjects with chronic constipation. RESULTS: Prune intake significantly decreased hard and lumpy stools while increasing normal stool and not increasing loose and watery stools. Prune intake also ameliorated subjective complaints of constipation and hard stools, without alteration of flatulence, diarrhea, loose stools, or urgent need for defecation. There were no adverse events or laboratory abnormalities of liver or renal function after prune intake. DISCUSSION: Prune juice exerted an effective and safe natural food therapy for chronic constipation.
