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such as graphene-based materials, boron nitride, and transition metal dichalcogenides, which have been predicted to show piezoelectric properties by density functional theory analysis. [3] Aerogels are porous materials with low density, high porosity, and high specific area. [4] Graphene aerogels (GAs), also known as 3D graphene, are macroscopic architectures assembled from graphene nanosheets. [5] GAs have high surface utilization and are suitable for surface functionalization. [6] The preparation methods of GAs are relatively simple, including self-assembly, [7] sacrificial template, [8] and 3D printing methods. [9] GAs have been widely investigated for the photothermal conversion, [10] electromagnetic shielding, [11] gas sensing, [12] surface catalysis, [13] and wearable devices. [14] GAs are assembled from the graphene sheets via van de Waals forces during the synthesis processes, where the physical connection between the graphene sheets provides macroscopic electrical conductivity. [15] In general, deformation occurs when an external pressure is applied to the GAs, which increases the area of contact between the graphene sheets, and increases the electrical conductivity. [16] It is this mechanism that makes GAs be suitable for piezoresistive sensors. The high sensitivity, wide linear range, good stability, low detection limit, and short response time are all critical features required for a piezoresistive sensor. [17] Although GAs meet most of these requirements due to their 3D interconnected architectures, the disordered microstructure of most isotropic GAs leads to a poor stability and a limited linearity, which severely limits their practical applications. [18] Innovative attempts to control the architectures with the introduction of orientation, reinforcing, wrinkling, and hierarchical pores can help to overcome these limitations. GAs with ordered microstructures can be prepared via air foaming, [19] 3D printing, and freeze-drying. [20] In the case of freeze-drying, the ice crystals act as a solid template, and the graphene sheets can aggregate along the ice crystals. [21] Parallel stacked lamellar architectures with a periodic arrangement could be produced via freeze-drying. [22] The unique architecture could result in Graphene-based aerogels (GAs) have been extensively studied for pressure sensing applications due to their high compressibility and conductivity. But the usually-adopted high-temperature treatment generally damages the flexibility and stability. It is still challenging to prepare piezoresistive sensors with a wide linear range, and reliable cyclic performance. Herein, we demonstrate an excellent wide-range piezoresistive sensor based on an aerogel of methylcellulose reinforced reduced graphene oxide (MC/GA). A steaming reduction at 120 °C is proposed to properly control the intermolecular forces and the chemical bonding between MC and GA. The finite element analysis indicates that wrinkled lamellae with hierarchical pores are beneficial to minimize the stress concentrations. As a result ...

Objective: To explore whether modified Chevron osteotomy together with distal soft tissue release would correct moderate to severe HV deformity and what is the minimal clinical important difference (MCID) for objective and subjective evaluating parameters.Methods: From March 2018 to January 2019, 40 hallux valgus patients (including moderate to severe) were enrolled in this retrospective study. The cohort included four males and 36 females. The average age at surgery was 50.95 (range 22-75) years. All patients underwent modified Chevron osteotomy together with distal soft tissue release and completed at least one follow-up at clinic. The American Orthopaedic Foot and Ankle forefoot score (AOFAS, forefoot), Visual Analog Scale (VAS), and Foot Function Index (FFI) were all collected before and after surgery. Besides, the hallux valgus angle (HVA), 1st-2nd intermetatarsal angle (IMA) and distal metatarsal articular angle (DMAA) were measured both before surgery and at last follow-up. All MCID values were calculated by employing distribution-based method.Results: Thirty-seven patients (92.5%) showed satisfied result at a mean 14.3-month follow-up (range 13-22 month).Two patients complained about residual pain at the bunion, and overcorrection (hallux varus) occurred in one patient. Meanwhile, no patient observed nonunion. Being female, age more than 60, residual HVA deformity (>15 ), and post IMA more than 9 showed no statistical relationship with the post-operation residual pain (P > 0.05). However, high VAS score before surgery (more than 7) showed strong correlation with residual pain (P < 0.01). The subjective MCID value was 9.50 for AOFAS, 18.92 for FFI, and 1.27 for VAS, respectively. Conclusion:The modified Chevron osteotomy together with distal soft tissue release could achieve a satisfied result for moderate to severe HV deformity at early follow-up. The residual pain was associated with severe pain before surgery (VAS more than 7).