Efficacy of biofeedback therapy via a mini wireless device on sleep bruxism contrasted with occlusal splint:a pilot study

The putative causes of bruxism are multifactorial and there are no definite measures for bruxism management.The aim of this study was to evaluate the efficacy of biofeedback therapy on sleep bruxism,compared with occlusal splint.Twenty-four volunteers with sleep bruxism were divided into two groups：the GTB group that were treated with biofeedback therapy（n 512） and the GTO group that were treated with occlusal splint（n 512）.A mini pressure sensor integrated with a monitoring circuit by use of a maxillary biofeedback splint was fabricated.To foster the relaxation of the masticatory muscles and the nervous system,the wireless device received signals from bruxism events and vibrations alerted the bruxer when the threshold was exceeded.Total episodes and average duration of bruxism events during8 hours of sleep were analyzed with the monitoring program（TRMY1.0）.After 6 and 12 weeks,the episodes（P 50.001） and duration（P,0.05） in the GTB group declined dramatically.In contrast,there were no significant differences in the GTO group after the treatment（P.0.05）.Furthermore,the episodes had significant differences between the GTB group and the GTO group after the same period of treatment（P 5 0.000）.The results suggest that biofeedback therapy may be an effective and convenient measure for mild bruxers,when compared with occlusal splint therapy.The mini wireless biofeedback method may be of value for the diagnosis and management of bruxism in the future.

Effects of different forms of nitrogen addition on microbial extracellular enzyme activity in temperate grassland soil

Background:Nitrogen(N)deposition alters litter decomposition and soil carbon(C)sequestration by influencing the microbial community and its enzyme activity.Natural atmospheric N deposition comprises of inorganic N(IN)and organic N(ON)compounds.However,most studies have focused on IN and its effect on soil C cycling,whereas the effect of ON on microbial enzyme activity is poorly understood.Here we studied the effects of different forms of externally supplied N on soil enzyme activities related to decomposition in a temperate steppe.Ammonium nitrate was chosen as IN source,whereas urea and glycine were chosen as ON sources.Different ratios of IN to ON(Control,10:0,7:3,5:5,3:7,and 0:10)were mixed with equal total amounts of N and then used to fertilize the grassland soils for 6 years.Results:Our results show that IN deposition inhibited lignin-degrading enzyme activity,such as phenol oxidase(POX)and peroxidase(PER),which may restrain decomposition and thus induce accumulation of recalcitrant organic C in grassland soils.By contrast,deposition of ON and mixed ON and IN enhanced most of the C-degrading enzyme activities,which may promote the organic matter decomposition in grassland soils.In addition,theβ-N-acetyl-glucosaminidase(NAG)activity was remarkably stimulated by fertilization with both IN and ON,maybe because of the elevated N availability and the lack of N limitation after long-term N fertilization at the grassland site.Meanwhile,differences in soil pH,soil dissolved organic carbon(DOC),and microbial biomass partially explained the differential effects on soil enzyme activity under different forms of N treatments.Conclusions:Our results emphasize the importance of organic N deposition in controlling soil processes,which are regulated by microbial enzyme activities,and may consequently change the ecological effect of N deposition.Thus,more ON deposition may promote the decomposition of soil organic matter thus converting C sequestration in grassland soils into a C source.

Artinian Local Rings Whose Annihilating-ideal Graphs Are Star Graphs

In this paper, a necessary and sufficient condition is given for a commutative Artinian local ring whose annihilating-ideal graph is a star graph. Also, a complete char- acterization is established for a finite local ring whose annihilating-ideal graph is a star graph.