Enhanced electron transport and self-similarity in quasiperiodic borophene nanoribbons with line defects.

Recent experiments have revealed multiple borophene phases of distinct lattice structures, suggesting that the unit cells of ν1/6 and ν1/5 boron sheets, namely α and ß chains, serve as building blocks to assemble into novel borophene phases. Motivated by these experiments, we present a theoretical study of electron transport along two-terminal quasiperiodic borophene nanoribbons (BNRs), with the arrangement of the α and ß chains following the generalized Fibonacci sequence. Our results indicate that the energy spectrum of these quasiperiodic BNRs is multifractal and characterized by numerous transmission peaks. In contrast to the Fibonacci model that all the electronic states should be critical, both delocalized and critical states appear in the quasiperiodic BNRs, where the averaged resistance saturates at the inverse of one conductance quantum for the delocalized states in the large length limit and contrarily exhibits a power-law dependence on the nanoribbon length for the critical states. Besides, the self-similarity is observed from the transmission spectrum, where the conductance curves overlap at different energy regions of two quasiperiodic BNRs of different Fibonacci indices and the resistance curves are analogous to each other at different energy scales of a single quasiperiodic BNR. These results complement previous studies on quasiperiodic systems where the multifractal energy spectrum and the self-similarity are observed by generating quasiperiodic potential energies, suggesting that borophene may provide an intriguing platform for understanding the structure-property relationships and exploring the physical properties of quasiperiodic systems.

[Treatment of Vascular Cognitive Impairment by "Huayu Tongluo" Moxibustion].

OBJECTIVE: To observe the therapeutic effect of "Huayu Tongluo"(blood stasis-removing and meridian-collateral-dredging) moxibustion for vascular cognitive impairment(VCI) patients and changes of insulin like growth factor -1(IGF-1) levels in serum after the treatment. METHODS: Sixty patients with VCI were randomly divided into medication (control) and moxibustion groups (n＝30 in each group). Cotton cloth-separated moxibustion was applied to Baihui (GV 20) and Shenting (GV 24), and conventional moxibustion applied to Dazhui (GV 14) and Yongquan (KI 1) for 30 min, once daily, 6 times a week and for 30 days. Patients of the control group were treated by oral administration of Donepezil hydrochloride at the dose of 5 mg/night for 30 days. The core symptoms of traditional Chinese medicine (TCM), mini-mental state examination(MMSE), activity of daily living(ADL) and Montreal cognitive assessment(MoCA) scales were used to assess the therapeutic effect after the treatment. The content of serum IGF-1 was determined by ELISA. RESULTS: Of the two 30 cases in the control and moxibustion groups, 9 and 17 experienced marked improvement, 13 and were effective, 8 and 3 ineffective, with the effective rates being 73.33% and 90.00%, respectively. The effective rate in the moxibustion group was obviously higher than that in the control group (P<0.05). After the treatment, the TCM symptom scores were significantly decreased, and the MMSE, ADL and MoCA scores considerably increased in both groups compared with those of their own individual pre-treatment (P<0.01). The TCM symptom score of the moxibustion group was significantly lower, and the MMSE and ADL scores were obviously higher than those of the control group (P<0.01). The serum IGF-1 content in both groups was significantly increased after the treatment relevant to that of their own individual pre-treatment (P<0.01), and was obviously higher in the moxibustion group than in the control group (P<0.01). No significant difference was found between the two groups in the MoCA score after the treatment (P>0.05)．. CONCLUSION: "Huayu Tongluo" moxibustion has a positive effect for patients with VCI, which may be associated with its effect in up-regulating serum IGF-1 level.