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Hu Zhiqing,Li Jiaji,Yu Ge,Lin Baojun 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.8
Clustering balls spinning method is a new method for fabricating curved surfaces by clustering rigid balls. It is always one of options to explore forming mechanism by using numerical simulation method that is closer to the real experimental process. In this article, we have adopted a new numerical model with multi-layer rigid balls (MlRB), which is named as MlRB model and more responsive to actual experiments. The model subroutine is developed based on the ABAQUS software. Simulation procedure using MlRB model is introduced, and cross-section, thickness distribution and springback using MlRB model are analyzed and compared to the experimental results and simulated results using previous numerical model with single-layer rigid balls (SlRB), which is named as SlRB model. The results are shown that, curved surface and thickness distribution simulated by MlRB model are closed to experimental results, and springback of curved surface is much less. Furthermore, auxiliary forming region that benefits to make the sheet deformed furtherly is proposed and analyzed. It is indicated that MlRB model is successful to simulate the deformation of the sheet according to the experiment, and it lays the foundation for the optimization of the technology parameters in the future.
Xie Zhongyu,Yu Wenhui,Ye Guiwen,Li Jinteng,Zheng Guan,Liu Wenjie,Lin Jiajie,Su Zepeng,Che Yunshu,Ye Feng,Zhang Zhaoqiang,Wang Peng,Wu Yanfeng,Shen Huiyong 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-
Mesenchymal stem cells (MSCs) are a common kind of multipotent cell in vivo, but their heterogeneity limits their further applications. To identify MSC subpopulations and clarify their relationships, we performed cell mapping of bone-marrow-derived MSCs through single-cell RNA (scRNA) sequencing. In our study, three main subpopulations, namely, the stemness subpopulation, functional subpopulation, and proliferative subpopulation, were identified using marker genes and further bioinformatic analyses. Developmental trajectory analysis showed that the stemness subpopulation was the root and then became either the functional subpopulation or the proliferative subpopulation. The functional subpopulation showed stronger immunoregulatory and osteogenic differentiation abilities but lower proliferation and adipogenic differentiation. MSCs at different passages or isolated from different donors exhibited distinct cell mapping profiles, which accounted for their corresponding different functions. This study provides new insight into the biological features and clinical use of MSCs at the single-cell level, which may contribute to expanding their application in the clinic.
Ye Guiwen,Li Jinteng,Yu Wenhui,Xie Zhongyu,Zheng Guan,Liu Wenjie,Wang Shan,Cao Qian,Lin Jiajie,Su Zepeng,Li Dateng,Che Yunshu,Fan Shuai,Wang Peng,Wu Yanfeng,Shen Huiyong 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-
Improving health and delaying aging is the focus of medical research. Previous studies have shown that mesenchymal stem cell (MSC) senescence is closely related to organic aging and the development of aging-related diseases such as osteoarthritis (OA). m6A is a common RNA modification that plays an important role in regulating cell biological functions, and ALKBH5 is one of the key m6A demethylases. However, the role of m6A and ALKBH5 in MSC senescence is still unclear. Here, we found that the m6A level was enhanced and ALKBH5 expression was decreased in aging MSCs induced by multiple replications, H2O2 stimulation or UV irradiation. Downregulation of ALKBH5 expression facilitated MSC senescence by enhancing the stability of CYP1B1 mRNA and inducing mitochondrial dysfunction. In addition, IGF2BP1 was identified as the m6A reader restraining the degradation of m6A-modified CYP1B1 mRNA. Furthermore, Alkbh5 knockout in MSCs aggravated spontaneous OA in mice, and overexpression of Alkbh5 improved the efficacy of MSCs in OA. Overall, this study revealed a novel mechanism of m6A in MSC senescence and identified promising targets to protect against aging and OA.