Lithium Niobate MEMS Antisymmetric Lamb Wave Resonators with Support Structures.

The piezoelectric thin film composed of single-crystal lithium niobate (LiNbO3) exhibits a remarkably high electromechanical coupling coefficient and minimal intrinsic losses, making it an optimal material for fabricating bulk acoustic wave resonators. However, contemporary first-order antisymmetric (A1) Lamb mode resonators based on LiNbO3 thin films face specific challenges, such as inadequate mechanical stability, limited power capacity, and the presence of multiple spurious modes, which restrict their applicability in a broader context. In this paper, we present an innovative design for A1 Lamb mode resonators that incorporates a support-pillar structure. Integration of support pillars enables the dissipation of spurious wave energy to the substrate, effectively mitigating unwanted spurious modes. Additionally, this novel approach involves anchoring the piezoelectric thin film to a supportive framework, consequently enhancing mechanical stability while simultaneously improving the heat dissipation capabilities of the core.

Dual-Mode Hybrid Quasi-SAW/BAW Resonators With High Effective Coupling Coefficient.

This article reports on a design journey for ScxAl1 - N-based dual-mode hybrid quasi-surface and bulk acoustic wave (quasi-SAW/BAW) resonators. Four types of acoustic excitation configurations are proposed in these designs based on Scx Al1-xN/6H-SiC stack architectures. The influence of Scx Al1-xN materials, film thickness, and device configurations on the performance is investigated. After design optimization, the final dual-mode hybrid quasi-SAW/BAW resonators comprise of top electrode, partially etched Scx Al1-xN pillars, and bottom electrode, which are stacked on a 6H-SiC substrate. The coupled quasi-SAW and BAW excited in the hybrid resonators enhance the resonance for both quasi-Rayleigh and quasi-Sezawa modes which results in a high effective coupling coefficient (Keff2) and phase velocity ( v ). Simulation results show that the optimized hybrid quasi-SAW/BAW resonator based on Mo/Sc0.4 Al0.6N/Mo/6H-SiC configuration with SiO2 filling the grooves has a remarkable Keff2 value of 14.55% and a high v above 7500 m/s, which make this kind of dual-mode hybrid quasi-SAW/BAW resonators have great potential in wideband and high-frequency applications.

Electroacupuncture exerts an anti-migraine effect via modulation of the 5-HT7 receptor in the conscious rat.

BACKGROUND: Acupuncture has been recommended as an alternative therapy for migraine. Emerging evidence suggests that the 5-HT7 receptor (5-HT7R) plays a significant facilitatory role in descending modulation in migraine pathophysiology, and that activation of 5-HT7R in the descending pathway is involved in migraine central sensitisation. OBJECTIVE: To investigate the ability of electroacupuncture (EA) to ameliorate central sensitisation via modulation of 5-HT7R in the descending pain pathways using a rat model of migraine induced by repetitive dural electrical stimulation (DES). DESIGN: 64 male Sprague-Dawley rats were randomly divided into four groups: Normal group; DES group (receiving dural electrical stimulation only); DES+GB20 group (DES model group treated with EA at GB20); and DES+Sham group (DES model group treated with EA at a non-traditional (sham) acupuncture point). The presence of cutaneous allodynia was determined by measuring facial and hind-paw withdrawal latencies to electronic von-Frey. The expression of 5-HT7R in the descending pathways (periaqueductal grey, raphe magnus nucleus, and trigeminal nucleus caudalis) was assessed using immunofluorescence and Western blotting. RESULTS: Facial and hind-paw withdrawal thresholds were significantly increased in the DES+GB20 group compared with the untreated DES group. The expression of 5-HT7R was significantly decreased in the DES+GB20 group compared with the DES group (one-way analysis of variance (ANOVA), P<0.05). No significant differences in behaviour or expression were found between the rats in the DES+Sham group and the untreated DES group (one-way ANOVA, P>0.05). CONCLUSION: EA at GB20 may ameliorate central sensitisation in migraine by inhibiting the activation of 5-HT7 receptors in the descending pain pathway in a rat model of migraine.

Effect of acupuncture on sleep quality and hyperarousal state in patients with primary insomnia: study protocol for a randomised controlled trial.

INTRODUCTION: Primary insomnia (PI) is commonly defined as a state of having disturbed daytime activities due to poor night-time sleep quality. Studies have demonstrated that it is a disorder of 24 h hyperarousal, expressed in terms of physiological, cognitive and cortical activation. Acupuncture is considered to be beneficial to restore the normal sleep-wake cycle. The aim of the trial is to assess the therapeutic effects of acupuncture on sleep quality and hyperarousal state in patients with PI. METHODS AND ANALYSIS: This study is a randomised, patient-assessor-blinded, sham controlled trial. -88 eligible patients with PI will be randomised in a ratio of 1:1 to the intervention group (real acupuncture) and control group (sham acupuncture, superficial insertion at irrelevant acupuncture points). Acupuncture intervention will be given to all participants three times a week for 4 weeks, followed up for 8 weeks.The primary outcome measures are the Pittsburgh Sleep Quality Index (PSQI) and Hyperarousal scale (HAS). The secondary outcomes are Fatigue scale-14 (FS-14), polysomnography (PSG), heart rate variability (HRV) and Morning Salivary Cortisol Level (MSCL). Outcomes will be evaluated at baseline, post-treatment period and 8 weeks follow-up. All main analyses will be carried out on the basis of the intention-to-treat principle. ETHICS/DISSEMINATION: This protocol has been approved by the Medical Ethical Committee of Beijing Traditional Chinese Medicine Hospital (Beijing TCM Hospital) on 5 January 2015. The permission number is 2014BL-056-02. The study will present data concerning the clinical effects of treating primary insomnia with acupuncture. The results will help to demonstrate if acupuncture is an effective therapy for improving sleep quality in association with a decreased hyperarousal level as a possible underlying mechanism. The findings from this study will be shared with the healthcare professionals, general public and relevant organisations through publication of manuscripts and conference presentations. TRIAL REGISTRATION NUMBER: ISRCTN16079489; Pre-results.