Research and development of a novel pneumatic-electric hybrid actuator

Jiabin Yang,Xiaoning Li 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

A novel pneumatic-electric hybrid actuator is studied and developed to enable precise positioning within a cylinder stroke in industrial automation. The proposed actuator will also allow engineers to overcome the defects of bias torque and structural coupling in the parallel type of pneumatic-electric hybrid actuators. The novel hybrid actuator consists of a coaxial cylinder layout, the motor lead screw pair, and the position sensor; a serial driving pattern is applied. A special reconfigurable positioning structure is designed for both the fixed and moving module; therefore, a decoupling motion can be achieved for the fast pneumatic motion and the electric precise fine-tuning motion without interference. In this paper, the authors presented the structure of this novel pneumatic-electric hybrid actuator and the accompanying mathematical model for pneumatic-electrical driving. Additionally, the control strategy with proportional-fuzzy mode and the subsection frequency control mode are presented. Experimental results show that the pneumatic-electric hybrid actuator has satisfying motion characteristics, including high speed, low overshoot, and small load sensitivity. Its positioning accuracy is ±0.01 mm, with a positioning time within 2 s, which is better than that of current pneumatic localizable actuators and pneumatic-electric hybrid actuators.

Completion hysterectomy after chemoradiotherapy for locally advanced adeno-type cervical carcinoma: updated survival outcomes and experience in post radiation surgery

Jie Yang,Jiaxin Yang,Dongyan Cao,Keng Shen,Jiabin Ma,Fuquan Zhang 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.2

Objective: To compare patient survival outcomes between completion hysterectomy and conventional surveillance in locally advanced adenocarcinoma of the cervix after concurrent chemoradiotherapy (CCRT). Methods: Patients with adenocarcinoma of the cervix after CCRT were identified in a tertiary academic center database from 2004 to 2018. Patients received completion hysterectomy or surveillance after CCRT. We compared the progression-free survival (PFS) and overall survival (OS) between the patients with or without adjuvant hysterectomy. Surgery features, operative complications, and pathologic characteristics were documented. Patient outcomes were also analyzed according to clinicopathologic factors. Results: A total of 78 patients were assigned to completion surgery and 97 to surveillance after CCRT. The PFS was better in the surgery group compared to the CCRT only group, at 3 years the PFS rates were 68.1% and 45.2%, respectively (hazard ratio [HR]=0.46; 95% confidence interval [CI]=0.282–0.749; p=0.002). Adjuvant surgery was also associated with a higher rate of OS (HR=0.361; 95% CI=0.189–0.689; p=0.002), at 3 years, 87.9% and 67%, respectively. Tumor stage, size, lymph-vascular space invasion (LVSI), lymphadenopathy were associated with PFS but not with OS. Hysterectomy specimens revealed 64.1% (50/78) of the patients had pathologic residual tumor. Patients age less than 60, tumor size over 4 cm, stage IIB and persistent residual disease after CCRT were most likely to benefit from hysterectomy. Hysterectomy was associated with a lower rate of locoregional recurrence but did not reach statistical significance (5.13% vs. 13.5%, p=0.067). Conclusion: Completion hysterectomy after CCRT was associated with better survival outcome compared with the current standard of care.

A Path Planning Method for Unmanned Surface Vessels in Dynamic Environment

Jiabin Yu,Zhihao Chen,Zhiyao Zhao,Jiping Xu,Yang Lu 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.4

A path planning method for unmanned surface vessels (USV) in dynamic environment is proposed to address the impact of dynamic environments on path planning results and the lack of dynamic obstacle avoidance capabilities. First, the considering ocean current rapidly exploring random tree (RRT*) (COC-RRT*) algorithm was proposed for global path planning. The RRT* algorithm has been enhanced with the integration of the virtual field sampling algorithm and ocean current constraint algorithm. The COC-RRT* algorithm optimizes the global planning path by adjusting the path between the parent nodes and child nodes. Second, according to the limitations of the International Regulations for Preventing Collisions at Sea (COLREGs), the improved dynamic window approach (DWA) is applied for local path planning. To enhance the ability of avoid dynamic obstacles, the dist function in the DWA algorithm has been improved. Simulation experiments were conducted in three scenarios to validate the proposed algorithm. The experimental results demonstrate that, in comparison with other algorithms, the proposed algorithm effectively avoids dynamic obstacles and mitigates the influence of the space-varying ocean current environment on the path-planning outcome. Additionally, the proposed algorithm exhibits high efficiency and robustness. The results verified the effectiveness of the proposed algorithm in dynamic environments.

Modified exosomal SIRPα variants alleviate white matter injury after intracerebral hemorrhage via microglia/macrophages

Xinjie Gao,Heng Yang,Weiping Xiao,Jiabin Su,Yuwen Zhang,He Wang,Wei Ni,Yuxiang Gu 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: Despite limited efficiency, modulation of microglia/macrophages has shown to attenuate neuroinflammation after intracerebral hemorrhage (ICH). In this context, we evaluated the efficacy of modified exosomal signal regulatory protein α (SIRPα) variants (SIRPα-v Exos) in microglia/macrophages and neuroinflammation-associated white matter injury after ICH. Methods: SIRPα-v Exos were engineered to block CD47-SIRPα interactions. After obtaining SIRPα-v Exos from lentivirus-infected mesenchymal stem cells, C57BL/6 mice suffering from ICH underwent consecutive intravenous injections of SIRPα-v Exos (6 mg/kg) for 14 days. Afterwards, the volume of hematoma and neurological dysfunctions were assessed in mice continuously until 35 days after ICH. In addition, demyelination, electrophysiology and neuroinflammation were evaluated. Furthermore, the mechanisms of microglial regulation by SIRPα-v Exos were investigated in vitro under coculture conditions. Results: The results demonstrated that the clearance of hematoma in mice suffering from ICH was accelerated after SIRPα-v Exo treatment. SIRPα-v Exos improved long-term neurological dysfunction by ameliorating white matter injury. In addition, SIRPα-v Exos recruited regulatory T cells (Tregs) to promote M2 polarization of microglia/macrophages in the peri-hematoma tissue. In vitro experiments further showed that SIRPα-v Exos regulated primary microglia in a direct and indirect manner in synergy with Tregs. Conclusion: Our studies revealed that SIRPα-v Exos could accelerate the clearance of hematoma and ameliorate secondary white matter injury after ICH through regulation of microglia/macrophages. SIRPα-v Exos may become a promising treatment for ICH in clinical practice.

Ultralarge elastic deformation of nanoscale diamond

Banerjee, Amit,Bernoulli, Daniel,Zhang, Hongti,Yuen, Muk-Fung,Liu, Jiabin,Dong, Jichen,Ding, Feng,Lu, Jian,Dao, Ming,Zhang, Wenjun,Lu, Yang,Suresh, Subra American Association for the Advancement of Scienc 2018 Science Vol.360 No.6386

<P>Diamonds have substantial hardness and durability, but attempting to deform diamonds usually results in brittle fracture. We demonstrate ultralarge, fully reversible elastic deformation of nanoscale (similar to 300 nanometers) single-crystalline and polycrystalline diamond needles. For single-crystalline diamond, the maximum tensile strains (up to 9%) approached the theoretical elastic limit, and the corresponding maximum tensile stress reached similar to 89 to 98 gigapascals. After combining systematic computational simulations and characterization of pre- and postdeformation structural features, we ascribe the concurrent high strength and large elastic strain to the paucity of defects in the small-volume diamond nanoneedles and to the relatively smooth surfaces compared with those of microscale and larger specimens. The discovery offers the potential for new applications through optimized design of diamond nanostructure, geometry, elastic strains, and physical properties.</P>