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宽温域VL型密封结构应力分析及寿命预测
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作者 孙德清 冯子明 +1 位作者 赵岩 董振刚 《化工机械》 CAS 2024年第3期423-432,共10页
建立VL密封结构模型,在不同温度条件下,研究其应力状态分布。以Miner损伤机理为基础,疲劳累计损伤理论为指导,研究不同温度条件下,VL型密封结构中O型橡胶圈、L型圈的疲劳寿命变化规律和疲劳寿命状况。结果表明:随着温度增加,O型橡胶圈的... 建立VL密封结构模型,在不同温度条件下,研究其应力状态分布。以Miner损伤机理为基础,疲劳累计损伤理论为指导,研究不同温度条件下,VL型密封结构中O型橡胶圈、L型圈的疲劳寿命变化规律和疲劳寿命状况。结果表明:随着温度增加,O型橡胶圈的Mises应力变化不大,疲劳寿命先增加后减小,当温度为25℃时,危险点处疲劳寿命最大,为7.341×10^(7)次,且疲劳寿命随着温度的增加,由局部变化转变为整体变化;L型圈的Mises应力由60.19 MPa逐渐减小到26.38 MPa,位置由底部开始,向内壁转移,最后到L型圈内部为止,最小疲劳寿命为2.21×10^(5)次。此外,在低温环境下,L型圈最小疲劳寿命较小,但平均疲劳寿命较大;在高温环境下,L型圈最小疲劳寿命较大,但平均疲劳寿命较小。 展开更多
关键词 VL型密封结构 宽温域 疲劳累计损伤理论
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PD-1抗体在小鼠胰腺癌中的治疗作用
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作者 刘文洁 孙德清 +1 位作者 闫蜜 岳春雯 《中国生化药物杂志》 CAS 2017年第11期7-9,11,共4页
目的评价PD-1抗体在小鼠原位胰腺癌中的治疗作用。方法将6~8w的C57小鼠采用原位注射Pan02细胞的方式构建原位胰腺癌模型,同时构建皮下瘤模型。将C57小鼠随机分为2组(PD-1抗体组和观察组)。PD-1抗体采用腹腔注射的方式,200ug/只,... 目的评价PD-1抗体在小鼠原位胰腺癌中的治疗作用。方法将6~8w的C57小鼠采用原位注射Pan02细胞的方式构建原位胰腺癌模型,同时构建皮下瘤模型。将C57小鼠随机分为2组(PD-1抗体组和观察组)。PD-1抗体采用腹腔注射的方式,200ug/只,观察组给予同等剂量的PBS。间隔5d给予一次,共行3次治疗。治疗结束后1w评价肿瘤的大小、CD8+T细胞的数目、血清中IFN-γ的水平,同时观察2组的生存期。结果2组小鼠瘤体的重量分别为(0.77±0.05)g和(1.44±0.07)g(P<0.01)。外周血中CD8+T细胞的数量分别为(27.96±1.84)%和(19.38±1.15)%(P<0.01)。肿瘤组织中CD8+T细胞的数量分别为(34.80±3.29)%和(22.45±1.78)%(P<0.01)。PD-1抗体组和PBS组小鼠血清中IFN-γ水平也存在统计学差异,分别为(39.01±3.08)pg/mL和(15.78±2.26)pg/mL(P<0.01)。PD-1抗体组小鼠的中位生存时间为52.6d(95%CI:48.4~5.76),而PBS组小鼠的中位生存时间为39.1d(95%CI:36.1~42.1)(P<0.01)。结论PD-1抗体能够增加外周血及肿瘤组织中的CD8+T细胞,并能够抑制小鼠原位胰腺癌的生长,且延长生存期。 展开更多
关键词 PD-1抗体 胰腺癌 CD8+T细胞 生存期
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Urolithin A protects dopaminergic neurons in experimental models of Parkinson disease by promoting mitochondrial biogenesis through SIRT1/PGC-1αsignaling pathway
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作者 LIU Jia QIU jing-ru +3 位作者 WANG Bao-zhu sun de-qing YU Shu-yan LOU Hai-yan 《中国药理学与毒理学杂志》 CAS 北大核心 2021年第9期648-649,共2页
OBJECTIVE Mitochondrial dys⁃function contributes to the pathogenesis of neuro⁃degenerative diseases such as Parkinson dis⁃ease(PD).Therapeutic strategies targeting mito⁃chondrial dysfunction hold considerable promise ... OBJECTIVE Mitochondrial dys⁃function contributes to the pathogenesis of neuro⁃degenerative diseases such as Parkinson dis⁃ease(PD).Therapeutic strategies targeting mito⁃chondrial dysfunction hold considerable promise for the treatment of PD.Urolithin A(UA)is a gut metabolite produced from ellagic acid-containing foods such as pomegranates,berries,and wal⁃nuts.Recent reports have highlighted the protec⁃tive role of UA in several neurological disorders including Alzheimer disease and ischemic stroke.However,the potential role of UA in PD has not been characterized.In this study,the role of UA in 6-OHDA-induced neurotoxicity in cell cultures and mouse model of PD was investi⁃gated.METHODS In vitro,PC12 cells were exposed to 6-OHDA in the presence or absence of UA.For in vivo study,C57BL/6 mice were ste⁃reotactic injected with 6-OHDA to induce experi⁃mental PD model.UA(10 mg·kg-1)was intraperi⁃toneal injected for 7 d before surgery.RESULTS UA protected against 6-OHDA cytotoxicity and apoptosis in PC12 cells.Prior administration of UA to 6-OHDA lesioned mice ameliorated both motor deficits and nigral-straital dopaminergic neurotoxicity.Moreover,UA attenuated 6-OHDA-induced mitochondrial dysfunction in PC12 cells accompanied by enhanced mitochondrial biogen⁃esis.Mechanically,the neuroprotective effects of UA were mediated by SIRT1-PGC-1αsignaling-mediated mitochondrial biogenesis.CONCLU⁃SION These data provide new insights into the novel role of UA in promoting mitochondria bio⁃genesis and suggest that UA may have potential therapeutic applications for PD. 展开更多
关键词 urolithin A Parkinson disease mito⁃chondrial biogenesis
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