Magneto-Thermomechanically Reprogrammable Mechanical Metamaterials.

Future active metamaterials for reconfigurable structural applications require fast, untethered, reversible, and reprogrammable (multimodal) transformability with shape locking. Magnetic control has a superior advantage for fast and remotely controlled deployment; however, a significant drawback is needed to maintain the magnetic force to hold the transformation, limiting its use in structural applications. The shape-locking property of shape-memory polymers (SMPs) can resolve this issue. However, the intrinsic irreversibility of SMPs may limit their reconfigurability as active metamaterials. Moreover, to date, reprogrammable methods have required high power with laser and arc welding proving to be energy-inefficient control methods. In this work, a magneto-thermomechanical tool is constructed and demonstrated, which enables a single material system to transform with untethered, reversible, low-powered reprogrammable deformations, and shape locking via the application of magneto-thermomechanically triggered prestress on the SMP and structural instability with asymmetric magnetic torque. The mutual assistance of two physics concepts-magnetic control combined with the thermomechanical behavior of SMPs is demonstrated, without requiring new materials synthesis and high-power energy for reprogramming. This approach can open a new path of active metamaterials, flexible yet stiff soft robots, multimodal morphing structures, and mechanical computing devices where it can be designed in reversible and reprogrammable ways.

Inverse design of 3D reconfigurable curvilinear modular origami structures using geometric and topological reconstructions.

The recent development of modular origami structures has ushered in an era for active metamaterials with multiple degrees of freedom (multi-DOF). Notably, no systematic inverse design approach for 3D curvilinear modular origami structures has been reported. Moreover, very few modular origami topologies have been studied to design active metamaterials with multi-DOF. Herein, we develop an inverse design method for constructing 3D reconfigurable architected structures - we synthesize modular origami structures whose unit cells can be volumetrically mapped into a prescribed 3D curvilinear shape followed by volumetric shrinkage to construct modules. After modification of the tubular geometry, we search through all the possible geometric and topological combinations of the modular origami structures to attain the target mobility using a topological reconstruction of modules. Our inverse design using geometric and topological reconstructions can provide an effective solution to construct 3D curvilinear reconfigurable structures with multi-DOF. Our work opens a path toward 3D reconfigurable systems based on volumetric inverse design, such as 3D active metamaterials and 3D morphing devices for automotive, aerospace, and biomedical engineering applications.

Study of preoperative diagnostic modalities in Chinese patients with superficial esophageal squamous cell carcinoma.

BACKGROUND: Endoscopic ultrasonography (EUS) and magnifying endoscopy (ME) reliably determine indications for endoscopic resection in patients with superficial esophageal squamous cell carcinoma (SESCC). ME is widely accepted for predicting the invasion depth of superficial esophageal cancer with satisfying accuracy. However, the addition of EUS is controversial. AIM: To evaluate the diagnostic efficiency of ME vs EUS for invasion depth prediction and investigate the influencing factors in patients with SESCC to determine the best diagnostic model in China. METHODS: We retrospectively analyzed patients with suspected SESCC who completed both ME and EUS and then underwent endoscopic or surgical resection at Sun Yat-Sen University Cancer Center between January 2018 and December 2021. We evaluated and compared the diagnostic efficiency of EUS and ME according to histological results, and investigated the influencing factors. RESULTS: We included 152 lesions from 144 patients in this study. The diagnostic accuracies of ME and EUS in differentiating invasion depth were not significantly different (73.0% and 66.4%, P = 0.24); both demonstrated moderate consistency with the pathological results (ME: kappa = 0.58, 95% confidence interval [CI]: 0.48-0.68, P < 0.01; EUS: kappa = 0.46, 95%CI: 0.34-0.57, P < 0.01). ME was significantly more accurate in the diagnosis of high-grade intraepithelial (HGIN) or carcinoma in situ (odds ratio [OR] = 3.62, 95%CI: 1.43-9.16, P = 0.007) subgroups. Using a miniature probe rather than conventional EUS can improve the accuracy of lesion depth determination (82.3% vs 49.3%, P < 0.01). Less than a quarter of circumferential occupation and application of a miniature probe were independent risk factors for the accuracy of tumor invasion depth as assessed by EUS (< 1/4 circumferential occupation: OR = 3.07, 95%CI: 1.04-9.10; application of a miniature probe: OR = 5.28, 95%CI: 2.41-11.59, P < 0.01). Of the 41 lesions (41/152, 27.0%) that were misdiagnosed by ME, 24 were corrected by EUS (24/41, 58.5%). CONCLUSION: Preoperative diagnosis of SESCC should be conducted endoscopically using white light and magnification. In China, EUS can be added after obtaining patient consent. Use of a high-frequency miniature probe or miniature probe combined with conventional EUS is preferable.

Influencing factors related to transcatheter arterial chemoembolization for hepatocellular carcinoma patients achieved tumor response.

Objective: To investigate the influencing factors of transcatheter arterial chemoembolization (TACE) on patients with hepatocellular carcinoma (HCC) for tumor response (complete and partial response, CR + PR). Methods: This research conducted a retrospective study of the hospital charts of patients treated with TACE successfully renewed from October 2014 to December 2015 at Sun Yat-sen University Cancer Center (Guangzhou, China). Univariate analysis (Chi-square test and repeated-measures ANOVA) selected nine influential tumor response factors from 22 core factors. The nine variables were included in a forward multiple logistic regression model predicting patients treated with TACE to achieve tumor response. Overall survival was calculated using the Kaplan-Meier method. Results: Data of 277 of 282 patients were included in the analysis. Nine variables were analyzed by univariate analysis and independently associated with tumor response (tumor capsule integrity, nausea and vomiting, microwave ablation, liver dysfunction, the absolute value of lymphocyte (LYM), alpha-fetoprotein, and gamma-glutamyl transpeptidase (GGT). By multivariate analysis, GGT (odds ratio [OR] =0.996), liver dysfunction (OR = 0.395), combined with microwave ablation (OR = 0.503), and tumor capsule integrity (OR = 1.894) were the significant predictors of the tumor response group compared with the standard deviation group (P < 0.05). Conclusions: This study suggests that TACE combined with ablation on patients with complete tumor capsules may have a better prognosis in tumor response and OS; additionally, liver dysfunction and nausea and vomiting were the independent predictors of tumor response.

Safety and efficacy of 125I brachytherapy for bilateral lung recurrences from hepatocellular carcinoma after resection or ablation.

PURPOSE: To evaluate the safety and efficacy of 125I brachytherapy to treat bilateral lung recurrences from hepatocellular carcinoma (HCC) after resection or ablation. MATERIALS AND METHODS: We retrospectively recruited 95 patients with bilateral lung recurrences from hepatocellular carcinoma (HCC) after resection or ablation who had received 3-6-month sorafenib with or without stereotactic body radiotherapy (SBRT), from October 2011 to January 2015; patients were then randomly divided into two groups, 44 patients received computed tomography (CT)-guided 125I brachytherapy (group A), and 51 patients were treated with supportive and symptomatic treatments (group B). RESULTS: The median survival time was 19 months (range of 3-36 months). The local response rate (LRR) at 3, 6, 12, 18, 24, 30 and 36 months in group A was 81.8%, 65.9%, 59.1%, 45.0%, 38.6%, 22.7%, 11.4%, respectively, and 64.7%, 47.1%, 33.3%, 25.4%, 15.7%, 11.7%, 7.8%, respectively, in group B (P < 0.05). The mean progression-free survival time (PFST) and overall survival (OS) of group A were significantly longer than those of group B. Alpha fetoprotein (AFP) and tumor size were independent factors that affected the PFST and OS, normal AFP levels and less than 1-cm tumor diameter had better PFST and OS (P < 0.05). No massive bleeding or serious complications occurred. CONCLUSION: CT-guided 125I brachytherapy is safe and effective for the treatment of bilateral lung recurrences from HCC after resection or ablation.