Clinical evidence for acupuncture for adult asthma: Systematic review and meta-analysis of randomised sham/placebo-controlled trials.

OBJECTIVE: Acupuncture is a widely used asthma therapy, but the benefits remain uncertain. This study aimed to access the effectiveness of acupuncture for treatment of asthma in adults. METHODS: Five English databases and four Chinese databases were searched from inception to November 2021. Randomised sham/placebo-controlled trials meeting inclusion criteria were included. Risk of bias was evaluated according to the Cochrane Review Handbook, and data analysis was performed in RevMan 5.4.1. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluations (GRADE) profiler. RESULTS: Sixteen randomised controlled trials (RCTs) were included in the meta-analysis. Results indicated that acupuncture was well-tolerated and could improve FEV1% compared with sham/placebo acupuncture [MD 6.11, 95% CI 0.54-11.68, I2 = 93%, number of participants (n) = 603]. Acupuncture also improved Cai's Asthma Quality of Life Questionnaire (AQLQ) (MD 7.26, 95% CI 5.02-9.50, I2 = 0, n = 358), and reduced the asthma symptom score (SMD -2.73, 95% CI -3.59 to -1.87, I2 = 65%, n = 120). One study showed acupuncture increased the Asthma Control Test (ACT) score (MD 2.00, 95% CI 0.90-3.10, n = 111), and decreased exacerbation frequency (MD -1.00, 95% CI -1.55 to -1.45, n = 111). Other lung function and medication use parameters were not statistically significant. CONCLUSIONS: Acupuncture versus sham/placebo control appeared to improve quality of life, FEV1%, symptoms, and asthma control, and reduced exacerbation frequency per year. Further studies with appropriate controls, more participants, and high-quality evidence are needed.

Highly Efficient Cellular Acoustic Absorber of Graphene Ultrathin Drums.

Atomically thin 2D graphene sheets exhibit unparalleled in-plane stiffness and large out-of-plane elasticity, thereby providing strong mechanical resonance for nanomechanical devices. The exceptional resonance behavior of ultrathin graphene, which promises the fabrication of superior acoustic absorption materials, however, remains unfulfilled for the lack of applicable form and assembly methods. Here, a highly efficient acoustic absorber is presented, wherein cellular networks of ultrathin graphene membranes are constructed into polymer foams. The ultrathin graphene drums exhibit strong resonances and efficiently dissipate sound waves in a broad frequency range. A record specific noise reduction coefficient (51.3 at 30 mm) is achieved in the graphene-based acoustic absorber, fully realizing the superior resonance properties of graphene sheets. The scalable method facilely transforms commercial polymer foams to superior acoustic absorbers with a ≈320% enhancement in average absorption coefficient across wide frequencies from 200 to 6000 Hz. The graphene acoustic absorber offers a convenient method to exploit the extraordinary resonance properties of 2D sheets, opening extensive new applications in noise protection, building design, instruments and acoustic devices.

Multifunctional Macroassembled Graphene Nanofilms with High Crystallinity.

A "cooling-contraction" method to separate large-area (up to 4.2 cm in lateral size) graphene oxide (GO)-assembled films (of nanoscale thickness) from substrates is reported. Heat treatment at 3000 °C of such free-standing macroscale films yields highly crystalline "macroassembled graphene nanofilms" (nMAGs) with 16-48 nm thickness. These nMAGs present tensile strength of 5.5-11.3 GPa (with ≈3 µm gauge length), electrical conductivity of 1.8-2.1 MS m-1 , thermal conductivity of 2027-2820 W m-1 K-1 , and carrier relaxation time up to ≈23 ps. As a demonstration application, an nMAG-based sound-generator shows a 30 µs response and sound pressure level of 89 dB at 1 W cm-2 . A THz metasurface fabricated from nMAG has a light response of 8.2% for 0.159 W mm-2 and can detect down to 0.01 ppm of glucose. The approach provides a straightforward way to form highly crystallized graphene nanofilms from low-cost GO sheets.

Surface acoustic wave humidity sensors based on uniform and thickness controllable graphene oxide thin films formed by surface tension.

Graphene oxide (GO) is a promising candidate for humidity sensing, and the uniformity and thickness of GO films are important for the reproducibility and test signal strength of humidity sensors. In this paper, uniform and thickness-controllable GO films are first formed by the surface tension of different concentrations of GO solution and then transferred to surface acoustic wave (SAW) humidity sensors. This GO film formation and transfer process has very good repeatability and stability, as evidenced by the humidity response of the sensors. With the help of the uniform and highly oxidized GO film, the humidity sensors show a significantly high sensitivity (absolute sensitivity of 25.3 kHz/%RH and relative sensitivity of 111.7 p.p.m./%RH) in a wide test range from 10%RH to 90%RH with very little hysteresis (<1%RH). The sensors achieve good reversibility, excellent short-term repeatability and stability. Moreover, the humidity sensors also show a fast response and recovery time of <10 s.