Novel Acid-Driven Bioinspired Self-Resettable Bilayer Hydrogel Actuator Mimicking Natural Muscles.

Soft robots have great potential applications in manufacturing, disaster rescue, medical treatment, etc. Artificial muscle is one of the most important components of a soft robot. In previous years, hydrogel actuators that can be controllably deformed by the stimuli of external signals have been developed as good candidates for muscle-like materials. In this article, we successfully prepared a chemical fuel-driven self-resettable bilayer hydrogel actuator mimicking natural muscles with the aid of a new negative feedback reaction network. The actuator can temporarily deform upon the addition of H+ (chemical fuel). Subsequently, H+ accelerated the reaction between BrO3- and Fe(CN)64-, which consume H+. It resulted in the spontaneous recovery of the pH as well as the shape of the actuator. Such an actuator exhibits a great similarity with natural muscles in actuation mechanisms and automaticity in the manipulation compared to the widely reported stimuli-responsive hydrogel actuators. This illustrates that fuel-driven self-resettable hydrogel is a promising dynamic material for mimicking the functions of living creatures.

Diagnostic accuracy of gastric filling ultrasonography in preoperative invasion depth (T stage) of gastric cancer: Meta-analysis.

OBJECTIVE: This study aimed to evaluate the diagnostic value of gastric filling ultrasonography in the preoperative invasion depth (T staging) of gastric cancer. METHODS: We systematically searched several online electronic databases including CNKI, Wanfang Medical Database, VIP, CBM, Pubmed, Embase, Cochrane Library, and Web of Science from January 2010 to December 2021, identifying the study about gastric filling ultrasonography for diagnostic of invasion depth of gastric cancer. Using bivariate mixed effect model to calculate the sensitivity (Sen), specificity (spe), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) with 95% confidence interval (CI). Draw the summary receiver operating characteristic (sROC) curve, likelihood ratio matrix and fagan diagram to evaluate the diagnostic value of gastric filling ultrasonography in the preoperative invasion depth of gastric cancer. Sen analysis and Publication bias tests were performed. RESULTS: This study obtained 21 literatures and the quality were good. The pooled Sen and spe of gastric filling ultrasonography was: T1: 0.63 (95% CI:0.51-0.73), 0.96 (95% CI:0.94-0.98); T2: 0.67 (95% CI:0.62-0.71), 0.90 (95% CI:0.88-0.93); T3: 0.79 (95% CI:0.75-0.82), 0.83 (95% CI:0.80-0.86); T4: 0.80 (95% CI:0.73-0.86), 0.96 (95% CI:0.94-0.97), respectively. In addition, the PLR and NLR of gastric filling ultrasonography was: T1: 16.74 (95% CI:9.98-28.09), 0.39 (95% CI:0.29-0.52); T2: 6.98 (95% CI:5.20-9.38), 0.36 (95% CI:0.31-0.42); T3: 4.65 (95% CI:3.78-5.73), 0.26 (95% CI:0.21-0.31); T4: 18.51 (95% CI:12.77-26.83), 0.20 (95% CI: 0.15-0.29), respectively. The DOR of gastric filling ultrasonography in T1-T4 was: 43.17 (95% CI:20.62-90.41),19.13 (95% CI:12.61-29.03), 18.15 (95% CI:12.86-25.62), 90.63 (95% CI:47.36-173.41), respectively. The sROC curve revealed that the area under the curve (AUC) of T1-T4 was: 0.93, 0.82, 0.87, 0.97, respectively. Sen analysis indicated that the study was steadily. And there is no publication bias in this study. But the study has some heterogeneity. CONCLUSION: Gastric filling ultrasonography is useful for clinical preoperative T staging of gastric cancer, and the result indicate that the accuracy of gastric filling ultrasonography in discriminating T1-T4 is higher than that in discriminating T2 - T3. It can be used as an imaging diagnostic method for preoperative T staging of gastric cancer.