目的观察土茯苓提取物落新妇苷对永生化人角质形成细胞Ha Ca T增殖、凋亡的影响,并探讨其机制。方法收集对数生长期Ha Ca T细胞,观察组分别加入不同浓度落新妇苷、空白对照组加DMEM培养液,培养24 h后,采用MTT法测算细胞增殖抑制率,流式...目的观察土茯苓提取物落新妇苷对永生化人角质形成细胞Ha Ca T增殖、凋亡的影响,并探讨其机制。方法收集对数生长期Ha Ca T细胞,观察组分别加入不同浓度落新妇苷、空白对照组加DMEM培养液,培养24 h后,采用MTT法测算细胞增殖抑制率,流式细胞仪检测细胞早期凋亡率;收集对数生长期Ha Ca T细胞,观察组分别加入不同浓度落新妇苷+20 ng/m L INF-γ、模型对照组加20 ng/m L INF-γ、空白对照组加DMEM培养液培养24 h,采用实时荧光定量PCR法检测细胞中的核转录因子κB(NF-κB)p65、骨桥蛋白(OPN)、血管内皮生长因子(VEGF)mRNA。结果落新妇苷在25、50、100、200、400μg/m L时,Ha Ca T细胞增殖抑制率分别为3.06%、26.53%、40.82%、60.20%及61.22%。落新妇苷在50、100、200μg/m L时,观察组Ha Ca T细胞早期凋亡率分别为3.26%、8.24%和15.38%;与空白对照组早期凋亡率(1.33%)比较,P均<0.05。与空白对照组比较,模型对照组NF-κB p65、OPN、VEGF mRNA表达增加(P均<0.01);与模型对照组比较,观察组随落新妇苷浓度增加,NF-κB p65、OPN、VEGF mRNA表达逐渐降低(P均<0.05)。结论土茯苓提取物落新妇苷能抑制Ha Ca T细胞增殖、诱导细胞凋亡,其机制可能与制抑细胞NF-κB p65、OPN、VEGF mRNA表达有关。展开更多
A method of three-dimensional loaded slope stability for anisotropic and nonhomogeneous slopes was presented based on the upper-bound theorem of the limit analysis approach. The approach can be considered as a modific...A method of three-dimensional loaded slope stability for anisotropic and nonhomogeneous slopes was presented based on the upper-bound theorem of the limit analysis approach. The approach can be considered as a modification and extension of the solutions. The influences of friction angle, anisotropy factor, nonhomogeneous factor, slope angle, ratio of width to depth, and load on the slope crest were investigated. The results show that solutions are suitable to deal with the purely cohesive soils and frictional/cohesive soils, isotropic and anisotropic, homogeneous and nonhomogeneous, loaded and unloaded cases.展开更多
The theory of limit analysis is presented for a three-dimensional stability problem of excavation. In frictional soil, the failure surface has the shape of logarithm helicoid, with the outline profile defined by a log...The theory of limit analysis is presented for a three-dimensional stability problem of excavation. In frictional soil, the failure surface has the shape of logarithm helicoid, with the outline profile defined by a log- spiral curve. The internal dissipation rate of energy caused by soil cohesion and gravity power of the failure soil is obtained through theoretical derivation. By solving the energy balance equation, the stability factor for the excavation is obtained. Influence of the ratio of width to height, the slope angle, and the top angle on the stability is examined. Numerical results of the proposed algorithm are presented in the form of non dimensional graph. Examples illustrate the practical use of the results.展开更多
A method of three-dimensional limited slope stability analysis is presented here based on the upperbound theorem of the limit analysis approach.A rotating collapse mechanism is considered in which energy dissipation t...A method of three-dimensional limited slope stability analysis is presented here based on the upperbound theorem of the limit analysis approach.A rotating collapse mechanism is considered in which energy dissipation takes place along curve velocity discontinuities.In the frictional soils,the failure surface has the shape of logarithm helicoids,with track outline defined by log-spirals.In the cohesive soils,the shape of the failure surface is torus.Angle is considered at slope top,and the critical height is less than top with no inclination.Numerical results of the proposed algorithm are presented in the form of nondimensional graphs.Some examples illustrate the practical use of the results.展开更多
文摘目的观察土茯苓提取物落新妇苷对永生化人角质形成细胞Ha Ca T增殖、凋亡的影响,并探讨其机制。方法收集对数生长期Ha Ca T细胞,观察组分别加入不同浓度落新妇苷、空白对照组加DMEM培养液,培养24 h后,采用MTT法测算细胞增殖抑制率,流式细胞仪检测细胞早期凋亡率;收集对数生长期Ha Ca T细胞,观察组分别加入不同浓度落新妇苷+20 ng/m L INF-γ、模型对照组加20 ng/m L INF-γ、空白对照组加DMEM培养液培养24 h,采用实时荧光定量PCR法检测细胞中的核转录因子κB(NF-κB)p65、骨桥蛋白(OPN)、血管内皮生长因子(VEGF)mRNA。结果落新妇苷在25、50、100、200、400μg/m L时,Ha Ca T细胞增殖抑制率分别为3.06%、26.53%、40.82%、60.20%及61.22%。落新妇苷在50、100、200μg/m L时,观察组Ha Ca T细胞早期凋亡率分别为3.26%、8.24%和15.38%;与空白对照组早期凋亡率(1.33%)比较,P均<0.05。与空白对照组比较,模型对照组NF-κB p65、OPN、VEGF mRNA表达增加(P均<0.01);与模型对照组比较,观察组随落新妇苷浓度增加,NF-κB p65、OPN、VEGF mRNA表达逐渐降低(P均<0.05)。结论土茯苓提取物落新妇苷能抑制Ha Ca T细胞增殖、诱导细胞凋亡,其机制可能与制抑细胞NF-κB p65、OPN、VEGF mRNA表达有关。
基金Projects(41002095,41172251,41272317) supported by the National Natural Science Foundation of China
文摘A method of three-dimensional loaded slope stability for anisotropic and nonhomogeneous slopes was presented based on the upper-bound theorem of the limit analysis approach. The approach can be considered as a modification and extension of the solutions. The influences of friction angle, anisotropy factor, nonhomogeneous factor, slope angle, ratio of width to depth, and load on the slope crest were investigated. The results show that solutions are suitable to deal with the purely cohesive soils and frictional/cohesive soils, isotropic and anisotropic, homogeneous and nonhomogeneous, loaded and unloaded cases.
基金the National Natural Science Foundation of China(Nos.41002095,41172251 and 41272317)
文摘The theory of limit analysis is presented for a three-dimensional stability problem of excavation. In frictional soil, the failure surface has the shape of logarithm helicoid, with the outline profile defined by a log- spiral curve. The internal dissipation rate of energy caused by soil cohesion and gravity power of the failure soil is obtained through theoretical derivation. By solving the energy balance equation, the stability factor for the excavation is obtained. Influence of the ratio of width to height, the slope angle, and the top angle on the stability is examined. Numerical results of the proposed algorithm are presented in the form of non dimensional graph. Examples illustrate the practical use of the results.
基金the National Natural Science Foundation of China(Nos.41172251 and 41002095)
文摘A method of three-dimensional limited slope stability analysis is presented here based on the upperbound theorem of the limit analysis approach.A rotating collapse mechanism is considered in which energy dissipation takes place along curve velocity discontinuities.In the frictional soils,the failure surface has the shape of logarithm helicoids,with track outline defined by log-spirals.In the cohesive soils,the shape of the failure surface is torus.Angle is considered at slope top,and the critical height is less than top with no inclination.Numerical results of the proposed algorithm are presented in the form of nondimensional graphs.Some examples illustrate the practical use of the results.
