Objectives To identify the efficacy of auricular acupressure on pain and disability for chronic LBP by systematic review. Methods A search of randomized controlled trials was conducted in four English medical electronic databases and three Chinese databases. Two reviewers independently retrieved related studies, assessed the methodological quality, and extracted data with a standardized data form. Meta-analyses were performed using all time-points meta-analysis. Results A total of 7 trials met the inclusion criteria, of which 4 had the low risk of bias. The findings of this study showed that, for the immediate effect, auricular acupressure had large, significant effects in improving pain within 12 weeks. As for the follow-up effect, the pooled estimates also showed promising effect at 4-week follow-up after 4-week intervention (standardized mean difference = −1.13, 95% CI (−1.70, −0.56), P < 0.001). But, for the disability level, the therapeutic effect was not significant (mean difference = −1.99, 95% CI (−4.93, 0.95), P = 0.18). No serious adverse effects were recorded. Conclusions The encouraging evidence of this study indicates that it is recommended to provide auricular acupressure to patients with chronic low back pain. However, a more accurate estimate of the effect will require further rigorously designed large-scale RCTs on chronic LBP for improving pain and disability.

The evolution of mining-induced stress field in longwall panel is closely related to the fracture field and the breaking characteristics of strata. Few laboratory experiments have been conducted to investigate the stress field. This study investigated its evolution by constructing a large-scale physical model according to the in situ conditions of the longwall panel. Theoretical analysis was used to reveal the mechanism of stress distribution in the overburden. The modelling results showed that: (1) The major principal stress field is arch-shaped, and the strata overlying both the solid zones and gob constitute a series of coordinated load-bearing structures. The stress increasing zone is like a macro stress arch. High stress is especially concentrated on both shoulders of the arch-shaped structure. The stress concentration of the solid zone in front of the gob is higher than the rear solid zone. (2) The characteristics of the vertical stress field in different regions are significantly different. Stress decreases in the zone above the gob and increases in solid zones on both sides of it. The mechanical analysis show that for a given stratum, the trajectories of principal stress are arch-shaped or inversely-arched, referred to as the “principal stress arch”, irrespective of its initial breaking or periodic breaking, and determines the fracture morphology. That is, the trajectories of tensile principal stress are inversely arched before the first breaking of the strata, and cause the breaking lines to resemble an inverted funnel. In case of periodic breaking, the breaking line forms an obtuse angle with the advancing direction of the panel. Good agreement was obtained between the results of physical modeling and the theoretical analysis.

This study presents a thorough literature review on the powder-bed laser additive manufacturing processes such as selective laser melting (SLM) of Inconel 718 parts. The paper first introduces the general aspects of powder-bed laser additive manufacturing and then discusses the unique characteristics and advantages of SLM. Moreover, the bulk of this study includes extensive discussions of microstructures and mechanical properties, together with the application ranges, of Inconel 718 parts fabricated by SLM.

Multiple myeloma (MM) is the most common cause of death from hematological malignancy worldwide, and recent studies have revealed that let-7b-5p can play an inhibitory role in tumorigenesis. However, the role of let-7b-5p in MM still remains unclear. The aim of this study was to elucidate the molecular mechanisms by which let-7b-5p acts as a tumor suppressor in MM. Here, quantitative real-time polymerase chain reaction results showed that the expression of let-7b-5p was remarkably reduced in MM tissues and MM cell lines (RPMI-8226 and U266 cells). Furthermore, over-expression of let-7b-5p significantly suppressed RPMI-8226 cell proliferation and induced S/G2 cell cycle arrest and apoptosis. Luciferase reporter assay results demonstrated that insulin-like growth factor receptor 1 (IGF1R) was negatively regulated by let-7b-5p at the post-transcriptional level. The mRNA and protein levels of IGF1R in RPMI-8226 cells were down-regulated by let-7b-5p. Furthermore, the cell phenotype altered by let-7b-5p inhibitor can be rescued by IGF1R silencing (si-IGF1R). Taken together, our results demonstrated that let-7b-5p functions as a tumor suppressor in MM, suggesting that let-7b-5p may be a potential therapeutic target for MM.

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