Clinical efficacy of acupuncture therapy combined with core muscle exercises in treating patients with chronic nonspecific low back pain: a systematic review and meta-analysis of randomized controlled trials.

Introduction: This meta-analysis aimed to determine the clinical efficacy of acupuncture combined with core muscle exercises on pain and functional status in patients with chronic nonspecific low back pain. Methods: This study followed the Preferred Reporting Items for Systematic Reviews and meta-analysis criteria for systematic reviews and meta-analyses. Randomized controlled trials published till November 2023 were searched in PubMed, Web of Science, Cochrane, Embase, China National Knowledge Infrastructure, Chinese Biomedical Literature, and Wanfang databases. The search strategy was related to disease type, intervention, and control measures and was structured around the search terms "low back pain," "acupuncture therapy," and "exercise." Two reviewers applied inclusion and exclusion criteria. Sensitivity and fixed effects analyses were performed to determine the primary outcomes. Results: We included 11 randomized controlled trials (n = 727) on acupuncture combined with core muscle exercises in patients with chronic nonspecific low back pain. Compared with controls, clinical efficacy was significant, with improvements in pain scores (visual analog pain scale and numerical rating scale) and Oswestry Disability Index in the intervention group. Discussion: Acupuncture therapy combined with core muscle exercises improved pain and functional status in patients with chronic nonspecific low back pain, with favorable clinical outcomes compared with single-core muscle training. Multicenter large-sample trials are required to obtain more reliable conclusions.

Full control of dual-band vortex beams using a high-efficiency single-layer bi-spectral 2-bit coding metasurface.

Vortex beams (VBs) carrying orbital angular moment (OAM) modes have been proven to be promising resources for increasing communication capacity. Although considerable attention has been paid on metasurface-based VB generators due to the unprecedented advantages of metasurface, most applications are usually limited at a single band with a fixed OAM mode. In this work, an emerging dual-band reflection-type coding metasurface is proposed to mitigate these issues by newly engineered meta-atoms, which could achieve independent 2-bit phase modulations at two frequency bands. The proposed coding metasurface could efficiently realize and fully control dual-band VBs carrying frequency selective OAM modes under the linearly polarized incidence. As the first illustrative example, a dual-band VB generator with normal beam direction is fabricated and characterized at two widely used communication bands (Ku and Ka bands). Moreover, by encoding proper coding sequences, versatile beams carrying frequency selective OAM modes can be achieved. Therefore, by adding a gradient phase sequence to the first VB generator, the second one is designed to steer the generated beams to a preset direction, which could enable diverse scenarios. The measurement results of both VB generators agree very well with the numerical ones, validating the full control capability of the proposed approach.

Simultaneous Realization of Anomalous Reflection and Transmission at Two Frequencies using Bi-functional Metasurfaces.

The capability to manipulating electromagnetic (EM) waves at the sub-wavelength scale has been enabled by metamaterials and their two-dimensional counterparts, metasurfaces. Especially, integrating two or more diverse functionalities into a single metasurface-based device is of great significance to meet the stringent requirements imposed by today's high frequency components and systems. Here, we present a dual-band bi-functional metasurface structure that could simultaneously achieve anomalous reflection and transmission at two terahertz (THz) frequencies, respectively, under linearly-polarized incident waves. To demonstrate the property of the proposed metasurface, a number of dual-band bi-functional metasurface-based components that could tailor the reflected and transmitted waves simultaneously are designed and verified numerically. Moreover, it is shown that both the amplitude and phase responses of the reflected and transmitted waves at two operating frequency bands (wavelengths) can be manipulated using the proposed metasurface, providing a new and convenient way to construct multi-functional metasurfaces and corresponding electromagnetic devices.