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  • 1
    Online Resource
    Online Resource
    Sintering quality and parameters optimization of sisal fiber/PES composite fabricated by selective laser sintering (SLS)
    SAGE Publications ; 2022
    In:  Journal of Thermoplastic Composite Materials Vol. 35, No. 10 ( 2022-10), p. 1632-1646
    Details
    In: Journal of Thermoplastic Composite Materials, SAGE Publications, Vol. 35, No. 10 ( 2022-10), p. 1632-1646
    Abstract: This article aims to improve the sintering quality of the sisal fiber/poly-(ether sulfone) (PES) composite (SFPC) part fabricated via selective laser sintering (SLS). The sisal fiber and PES powders were proposed as the feedstock of the SFPC powder bed for SLS. An orthogonal experimental methodology with four levels and five factors was applied to optimize the process parameters for the single-layer sintering experiment. The mechanical properties and accurate dimensions of the sintered part were tested using a universal testing machine and Vernier caliper. The preheating temperature, scanning speed, and laser power were selected as influencing factors on the mechanical properties and accuracy dimensions of the SFPC part. Furthermore, the influence factors on the quality of the sintered part were studied and analyzed. Additionally, the synthesis weighted scoring method was used to determine the optimum parameters of the SLS part. The results showed that the optimal parameters (factors) were preheating temperature of 82°C, scanning speed of 2 m s −1 , laser power of 14 W, and laser wavelength of 10.6 μm. Thus, the quality of SFPC part was significantly enhanced when the optimum parameters were applied in SLS process. This article provided the main reference value for the choice of the process parameters of the biomass composite.
    Type of Medium: Online Resource
    ISSN: 0892-7057 , 1530-7980
    URL: Article
    DOI: 10.1177/0892705720939179
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2022
    detail.hit.zdb_id: 2098671-3
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  • 2
    Online Resource
    Online Resource
    Hierarchically Planning Static Gait for Quadruped Robot Walking on Rough Terrain
    Hindawi Limited ; 2019
    In:  Journal of Robotics Vol. 2019 ( 2019-05-02), p. 1-12
    Details
    In: Journal of Robotics, Hindawi Limited, Vol. 2019 ( 2019-05-02), p. 1-12
    Abstract: Quadruped robot has great potential to walk on rough terrain, in which static gait is preferred. A hierarchical structure based controlling algorithm is proposed in this paper, in which trajectory of robot center is searched, and then static gaits are generated along such trajectory. Firstly, cost map is constructed by computing terrain features under robot body and cost of selecting footholds at default positions, and then the trajectory of robot center in 2D space is searched using heuristic A ⁎ algorithm. Secondly, robot state is defined from foothold and robot pose, and then state series are searched recursively along the trajectory of robot center to generate static gaits, where a tree-like structure is used to store such states. Lastly, a classical model for quadruped robot is designed, and then the controlling algorithm proposed in the paper is demonstrated on such robot model for both structured terrain and complex unstructured terrain in a simulation environment.
    Type of Medium: Online Resource
    ISSN: 1687-9600 , 1687-9619
    URL: Article
    DOI: 10.1155/2019/3153195
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2019
    detail.hit.zdb_id: 2582988-9
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  • 3
    Online Resource
    Online Resource
    Learning the Cost Function for Foothold Selection in a Quadruped Robot
    MDPI AG ; 2019
    In:  Sensors Vol. 19, No. 6 ( 2019-03-14), p. 1292-
    Details
    In: Sensors, MDPI AG, Vol. 19, No. 6 ( 2019-03-14), p. 1292-
    Abstract: This paper is focused on designing a cost function of selecting a foothold for a physical quadruped robot walking on rough terrain. The quadruped robot is modeled with Denavit–Hartenberg (DH) parameters, and then a default foothold is defined based on the model. Time of Flight (TOF) camera is used to perceive terrain information and construct a 2.5D elevation map, on which the terrain features are detected. The cost function is defined as the weighted sum of several elements including terrain features and some features on the relative pose between the default foothold and other candidates. It is nearly impossible to hand-code the weight vector of the function, so the weights are learned using Supporting Vector Machine (SVM) techniques, and the training data set is generated from the 2.5D elevation map of a real terrain under the guidance of experts. Four candidate footholds around the default foothold are randomly sampled, and the expert gives the order of such four candidates by rotating and scaling the view for seeing clearly. Lastly, the learned cost function is used to select a suitable foothold and drive the quadruped robot to walk autonomously across the rough terrain with wooden steps. Comparing to the approach with the original standard static gait, the proposed cost function shows better performance.
    Type of Medium: Online Resource
    ISSN: 1424-8220
    URL: Article
    DOI: 10.3390/s19061292
    Language: English
    Publisher: MDPI AG
    Publication Date: 2019
    detail.hit.zdb_id: 2052857-7
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  • 4
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    An enhanced honey badger algorithm based on Lévy flight and refraction opposition-based learning for engineering design problems
    IOS Press ; 2022
    In:  Journal of Intelligent & Fuzzy Systems Vol. 43, No. 4 ( 2022-08-10), p. 4517-4540
    Details
    In: Journal of Intelligent & Fuzzy Systems, IOS Press, Vol. 43, No. 4 ( 2022-08-10), p. 4517-4540
    Abstract: Honey badger algorithm (HBA) is a recently developed meta-heuristic algorithm, which mainly simulates the dynamic search behavior of honey badger in wild nature. Similar to other basic algorithms, HBA may suffer from the weakness of poor convergence accuracy, inadequate balance between exploration and exploitation, and ease of getting trapped into the local optima. In order to address these drawbacks, this paper proposes an enhanced honey badger algorithm (EHBA) to improve the search quality of the basic method from three aspects. First, we introduce the highly disruptive polynomial mutation to initialize the population. This is considered from increasing the population diversity. Second, Lévy flight is integrated into the position update formula to boost search efficiency and balance exploration and exploitation capabilities of the algorithm. Furthermore, the refraction opposition-based learning is applied to the current global optimum of the swarm to help the population jump out of the local optima. To validate the function optimization performance, the proposed EHBA is comprehensively analyzed on 18 standard benchmark functions and IEEE CEC2017 test suite. Compared with the basic HBA and seven state-of-the-art algorithms, the experimental results demonstrate that EHBA can outperform other competitors on most of the test functions with superior solution accuracy, local optima avoidance, and stability. Additionally, the applicability of the proposed method is further highlighted by solving four engineering design problems. The results indicate that EHBA also has competitive performance and promising prospects for real-world optimization tasks.
    Type of Medium: Online Resource
    ISSN: 1064-1246 , 1875-8967
    URL: Article
    DOI: 10.3233/JIFS-213206
    Language: Unknown
    Publisher: IOS Press
    Publication Date: 2022
    detail.hit.zdb_id: 2070080-5
    SSG: 11
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  • 5
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    Online Resource
    Mir-20a-5p induced WTX deficiency promotes gastric cancer progressions through regulating PI3K/AKT signaling pathway
    Springer Science and Business Media LLC ; 2020
    In:  Journal of Experimental & Clinical Cancer Research Vol. 39, No. 1 ( 2020-12)
    Details
    In: Journal of Experimental & Clinical Cancer Research, Springer Science and Business Media LLC, Vol. 39, No. 1 ( 2020-12)
    Abstract: The X-linked gene WTX (also called AMER1) has been reported to function as a tumour suppressor gene in Wilms’ tumour. In our previous study, WTX expression was shown to be significantly reduced in gastric cancer (GC), but the function and mechanism associated with WTX loss had yet to be fully elucidated. Methods WTX expression and clinical significance were father analyzed in GC and control normal gastric tissues, and validated in public databases. The candidate pathway which was regulated by WTX during GC progression was searched by KEGG pathway analysis. The miRNA which monitored WTX expression was screened by miRNA microarray. After verified the pathway and miRNA both in vitro and in vivo, the relationship of miRNA, WTX and the downstream pathway were analyzed by Western blot, immunohistochemistry, RT-PCR, Co-immunoprecipitation (Co-IP), and luciferase analyses. Results The results showed that WTX serves as a tumour suppressor gene in GC. The loss of WTX which is associated with the aggressiveness of GC by promoting GC cell proliferation in vitro and high metastasis in vivo . Furthermore, WTX expression was positively correlated with the overall survival of GC patients. Microarray assays, bioinformatics analysis, and verification experiments showed that WTX loss activates the PI3K/AKT/mTOR pathway and promotes GC cell proliferation and invasion. And the aberrant miR-20a-5p upregulation contributes to WTX loss in GC, which stimulates PI3K phosphorylation to activate PI3K/AKT/mTOR signaling pathway and promoted GC progression. Conclusions The results of the present study elucidated the mechanism of GC progression, which is at least partially caused by aberrant miR-20a-5p upregulation leading to the inhibition of WTX expression and PI3K/AKT/mTOR signaling pathway activation. These findings provide a comprehensive understanding of the action of the miR-20a-5p/WTX/PI3K/AKT/mTOR signaling pathway in the progression and metastasis of GC.
    Type of Medium: Online Resource
    ISSN: 1756-9966
    URL: Article
    DOI: 10.1186/s13046-020-01718-4
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2020
    detail.hit.zdb_id: 2430698-8
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  • 6
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    Correction to: Mir-20a-5p induced WTX deficiency promotes gastric cancer progressions through regulating PI3K/AKT signaling pathway
    Springer Science and Business Media LLC ; 2021
    In:  Journal of Experimental & Clinical Cancer Research Vol. 40, No. 1 ( 2021-12)
    Details
    In: Journal of Experimental & Clinical Cancer Research, Springer Science and Business Media LLC, Vol. 40, No. 1 ( 2021-12)
    Abstract: An amendment to this paper has been published and can be accessed via the original article.
    Type of Medium: Online Resource
    ISSN: 1756-9966
    URL: Article
    DOI: 10.1186/s13046-020-01809-2
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 2430698-8
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  • 7
    Online Resource
    Online Resource
    Design and Experiment of a Hand Movement Device Driven by Shape Memory Alloy Wires
    Hindawi Limited ; 2021
    In:  Journal of Robotics Vol. 2021 ( 2021-3-30), p. 1-13
    Details
    In: Journal of Robotics, Hindawi Limited, Vol. 2021 ( 2021-3-30), p. 1-13
    Abstract: Hand is one of the most flexible and useful organs of the human body. However, cases of hand function loss due to diseases and accidents abound, which brings a lot of inconvenience to patients’ lives. This paper introduced a flexible hand movement device (HMD) driven by shape memory alloy (SMA) wires, which is compact, lightweight, and easy to use during activities of daily living (ADL). Firstly, we elaborated the design and modelling process, including the driving analysis of SMA wires. Secondly, the manufacturing process and testing method of the HMD are presented. Thirdly, the results of the experiment are discussed in detail. Through the experiment, we obtained the bending angle and operating space of fingers. Moreover, the joint angle as well as the fingertip force can be controlled using PWM. A maximum angular movement of 45°, 62°, and 71° can be generated at the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal joints (DIP) of a finger using an SMA wire, respectively. Then, the operating space of the entire hand can be calculated based on the experimental results. Besides, an estimated 40 N of grasping force can be produced for a whole hand. In conclusion, this research indicates that the finger movement driven by the HMD is similar to a healthy person, which can meet the needs of ADL.
    Type of Medium: Online Resource
    ISSN: 1687-9619 , 1687-9600
    URL: Article
    DOI: 10.1155/2021/6611581
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2582988-9
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  • 8
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    3 D printing technology and experimental study of chitosan gel using atomized solidification liquid-assisted extrusion molding
    Emerald ; 2022
    In:  Rapid Prototyping Journal Vol. 28, No. 1 ( 2022-01-03), p. 101-108
    Details
    In: Rapid Prototyping Journal, Emerald, Vol. 28, No. 1 ( 2022-01-03), p. 101-108
    Abstract: This paper aims to propose a suitable atomizing solidification chitosan (CS) gel liquid extrusion molding technology for the three dimensional (3D) printing method, and experiments verify the feasibility of this method. Design/methodology/approach This paper mainly uses experimental means, combined with theoretical research. The preparation method, solidification forming method and 3D printing method of CS gel solution were studied. The CS gel printing mechanism and printing error sources are analyzed on the basis of the CS gel ink printing results, printing performance with different ratios of components by constructing a gel print prototype, experiments evaluating the CS gel printing technology and the effects of the process parameters on the scaffold formation. Findings CS printing ink was prepared; the optimal formula was found; the 3 D printing experiment of CS was completed; the optimal printing parameters were obtained; and the reliability of the forming prototype, printing ink and gel printing process was verified, which allowed for the possibility to apply the 3 D printing technology to the manufacturing of a CS gel structure. Originality/value This study can provide theoretical and technical support for the potential application of CS 3 D printed gels in tissue engineering.
    Type of Medium: Online Resource
    ISSN: 1355-2546 , 1355-2546
    URL: Article
    DOI: 10.1108/RPJ-10-2020-0234
    Language: English
    Publisher: Emerald
    Publication Date: 2022
    detail.hit.zdb_id: 2002657-2
    SSG: 11
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  • 9
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    Resveratrol reverses Doxorubicin resistance by inhibiting epithelial-mesenchymal transition (EMT) through modulating PTEN/Akt signaling pathway in gastric cancer
    Springer Science and Business Media LLC ; 2017
    In:  Journal of Experimental & Clinical Cancer Research Vol. 36, No. 1 ( 2017-01-26)
    Details
    In: Journal of Experimental & Clinical Cancer Research, Springer Science and Business Media LLC, Vol. 36, No. 1 ( 2017-01-26)
    Abstract: Gastric cancer is one of the major causes of cancer-related mortality worldwide. Most of patients presenting with inoperable gastric cancers rely on systemic chemotherapy for prolongation of survival. Doxorubicin (DOX) is one of the important agents against gastric cancer. Acquired DOX-resistance severely impedes the chemotherapeutic effect, invariably leading to poor prognosis. Resveratrol (RES) as a kind of phytoalexin has demonstrated anti-tumor functions in breast cancer and myeloid leukemia, but its function and mechanism are still unknown in gastric cancer treatment. Methods CCK8 assay was used to detect the cytotoxicity of DOX and RES to gastric cancer cells. DOX-resistant subclone cell line (SGC7901/DOX) was derived from SGC7901 cells exposed to stepwise increasing concentrations of DOX treatment. We measured the migratory capabilities of SGC7901/DOX cells by Cell scratch test and Transwell assay. SGC7901/DOX cells were treated with DOX, RES, neither or both. Then we analyzed cell survival by CCK8 assay, colony formation by Colony-forming assay, cell apoptosis by Annexin-V-FITC and PI dual staining assay and cell migration by Cell scratch test and Transwell assay. Western blotting was conducted to detect the protein expressions of PTEN/Akt signaling pathway and EMT-related markers. Immunofluorescence was performed to confirm the EMT-related markers expressions. The xenograft model was used to assess the effect of DOX and RES in vivo. The key molecules associated with proliferation, apoptosis and EMT were evaluated by immunohistochemistry in tumor specimens. Results SGC7901/DOX cells acquired drug resistance and enhancive migratory capability. RES enabled SGC7901/DOX cells to regain DOX sensitivity, mitigated the aggressive biological features, promoted cell apoptosis in vitro and inhibited tumor growth in vivo. Mechanistic studies revealed that SGC7901/DOX cells underwent epithelial-mesenchymal transition (EMT) which was induced by Akt activation, and through activating PTEN, RES inhibited the Akt pathway, and then achieved the reversion of EMT. Conclusion RES serves as a novel solution to reverse the DOX-resistance of gastric cancer via preventing EMT by modulating PTEN/Akt signaling pathway. DOX-RES combined treatment provides a promising future for gastric cancer patients to postpone drug resistance and prolong survival.
    Type of Medium: Online Resource
    ISSN: 1756-9966
    URL: Article
    DOI: 10.1186/s13046-016-0487-8
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2017
    detail.hit.zdb_id: 2430698-8
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  • 10
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    Online Resource
    A flexible hingeless control surface inspired by aquatic animals
    Springer Science and Business Media LLC ; 2010
    In:  Journal of Bionic Engineering Vol. 7, No. 4 ( 2010-12), p. 364-374
    Details
    In: Journal of Bionic Engineering, Springer Science and Business Media LLC, Vol. 7, No. 4 ( 2010-12), p. 364-374
    Type of Medium: Online Resource
    ISSN: 1672-6529 , 2543-2141
    URL: Article
    DOI: 10.1016/S1672-6529(10)60268-5
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2010
    detail.hit.zdb_id: 2233712-X
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