ABSTRACT
Unlike graphene derived from graphite, borophenes represent a distinct class of synthetic two-dimensional materials devoid of analogous bulk-layered allotropes, leading to covalent bonding within borophenes instead of van der Waals (vdW) stacking. Our investigation focuses on 665 vdW-stacking boron bilayers to uncover potential bulk-layered boron allotropes through vdW stacking. Systematic high-throughput screening and stability analysis reveal a prevailing inclination toward covalently bonded layers in the majority of boron bilayers. However, an intriguing outlier emerges in δ5 borophene, demonstrating potential as a vdW-stacking candidate. We delve into electronic and topological structural similarities between δ5 borophene and graphene, shedding light on the structural integrity and stability of vdW-stacked boron structures across bilayers, multilayers, and bulk-layered allotropes. The δ5 borophene analogues exhibit metallic properties and characteristics of phonon-mediated superconductors, boasting a critical temperature near 22 K. This study paves the way for the concept of "borophite", a long-awaited boron analogue of graphite.
ABSTRACT
OBJECTIVE@#To compare the clinical effect of electroacupuncture at Siguan points and flunarizine hydrochloride capsule on migraine of liver yang hyperactivity.@*METHODS@#A total of 110 patients with migraine of liver yang hyperactivity were randomly divided into an electroacupuncture group (55 cases, 2 cases dropped off) and a western medication group (55 cases, 2 cases dropped off). In the electroacupuncture group, electroacupuncture was applied at Siguan points (Hegu [LI 4] and Taichong [LR 3]), with disperse-dense wave of 2 Hz/100 Hz in frequency and current intensity of 0.1-1 mA, 30 min each time, once a day, 5 times per week for 4 weeks. Flunarizine hydrochloride capsule was given orally in the western medication group, 10 mg a day for 4 weeks. The visual analogue scale (VAS) score and the migraine attack days were observed before and after treatment, during follow-up of 1, 3 and 6 months, and the migraine symptom score was observed before and after treatment in the two groups.@*RESULTS@#After treatment, during follow-up of 1, 3 and 6 months, the VAS scores and the migraine attack days in the two groups were decreased compared with before treatment (Ｐ<0.05), and above indexes in the electroacupuncture group were lower than the western medication group (Ｐ<0.05). After treatment, the migraine symptom scores in the two groups were decreased (Ｐ<0.05), the change in the electroacupuncture group was greater than the western medication group (Ｐ<0.05).@*CONCLUSION@#Electroacupuncture at Siguan points could effectively reduce headache intensity and migraine attack days, relieve migraine symptoms in patients with migraine of liver yang hyperactivity, and the efficacy is superior to oral flunarizine hydrochloride capsules.
Subject(s)
Humans , Acupuncture Points , Electroacupuncture , Flunarizine/therapeutic use , Liver , Migraine Disorders/therapyABSTRACT
We propose a series of planar boron allotropes with honeycomb topology and demonstrate that their band structures exhibit Dirac cones at the K point, the same as graphene. In particular, the Dirac point of one honeycomb boron sheet locates precisely on the Fermi level, rendering it as a topologically equivalent material to graphene. Its Fermi velocity (vf) is 6.05 × 105 m/s, close to that of graphene. Although the freestanding honeycomb B allotropes are higher in energy than α-sheet, our calculations show that a metal substrate can greatly stabilize these new allotropes. They are actually more stable than α-sheet sheet on the Ag(111) surface. Furthermore, we find that the honeycomb borons form low-energy nanoribbons that may open gaps or exhibit strong ferromagnetism at the two edges in contrast to the antiferromagnetic coupling of the graphene nanoribbon edges.
