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Numerical simulations illustrate the half-cell law of regular cellular detonations propagating in confined space, i.e., the number of cells always maintains an integral multiple of half cell. The cells adapt themselves larger or smaller to the size of the unconfined space by maintaining the cell scale larger or smaller than the original cells of detonation. 相似文献
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肿瘤细胞和所处微环境的物理性质, 以及它们之间的相互物理作用对于肿瘤的产生、发展与转移都有极大的影响, 这使得从物理学角度探索肿瘤研究成为了必然趋势. 肿瘤转移是癌症致死的最大因素, 而肿瘤细胞迁移中的极化是肿瘤转移的重要一步. 本文总结了物理学实验和模型在揭示细胞迁移和极化机理方面的贡献. 实验上应用最新的微流控芯片技术与表面微模型化技术等手段, 研究空间维度、黏附行为、机械力等物理信号对于细胞极性的建立与保持以及细胞迁移行为的影响后, 发现物理信号与生化反应之间的相互耦合对于细胞迁移有着至关重要的作用; 理论上基于扩散反应方程, 已经建立了一系列表征细胞极化的模型. 今后的研究将结合物理实验建立肿瘤细胞迁移中的极化模型, 进而发展针对肿瘤细胞感知物理信号的新的治疗肿瘤转移方法. 相似文献
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随着科学技术的发展以及稳态强磁场在医疗诊断中的广泛应用,人们接触到1 T以上稳态强磁场的机会越来越多,稳态强磁场对人体健康的潜在影响也备受关注.虽然目前由于实验条件的限制,稳态强磁场对动物以及人体的研究报道依然有限,但是细胞作为生物体的基本单位,其研究相对较多.然而由于实验中磁场参数、细胞类型等各种因素的不同,使得稳态强磁场对细胞的影响在不同的研究中存在着差异.因此,本文不仅总结和分析了国内外1 T以上稳态强磁场细胞生物学效应的相关研究,包括细胞取向、增殖、微管和纺锤体等,而且对现有研究结果进行比较和概括,并对可能造成实验差异的因素进行分析,例如磁场强度和细胞类型等,从而为下一步研究稳态强磁场下的细胞生物学效应提供基础和依据. 相似文献
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We propose a mathematical model to analyse the membrane tether formation process on a cell surface with reservoir. Based on the experimental results, the membrane reservoir density of breast cancer cell was obtained, ρ=8.02. The membrane surface viscosity between membrane and environment η is 0.021(pN.s/μm^3), and the static force F0=5.71pN. 相似文献
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We investigate the activation of living monocytic U937 cells induced by interleukin-6 (IL-6) at the single cell level. We employ home-built Raman tweezers to measure the Raman spectra of living U937 cells with and without IL-6 at the single cell level. Raman peaks of amide III, amide I, DNA backbone, as well as guanine and adenine in U937 cells, change at 1312, 1652, 1090, and 1576 cm ?1 , respectively, shortly after IL-6 is added in the medium. The change is a dynamic temporal process. In the activation process of U937 cells induced by IL-6, the protein signals recover in 20 min, while the nucleic acid signals continue to increase for 20 min. The results reveal that the biochemical cascades of activation in signal transduction induced by IL-6 can be investigated in situ at the single cell level. 相似文献
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利用NaOH碱式消化快脉冲雾化原子吸收法测定培养细胞内的K,… 总被引:2,自引:0,他引:2
用6%的NaOH碱式消化培养细胞,取50μl消化液,用考马斯亮蓝法测定蛋白含量,共余用La-EDTA等量稀后,采用自制微量进样装置,运用快脉冲雾化技术,使进样体积最低降至20μl在日立180-80型原子吸收分光光度计上测定K,Ca和Mg含量,结果以每克蛋白含量表示。 相似文献
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通过对不同处理条件和测试条件下人肝癌细胞SMMC-7721的原子力显微镜图像的分析和研究,得到了在大气环境和溶液环境中肝癌SMMC-7721细胞的最佳成像条件,同时建立了用原子力显微镜观测活细胞的实验方法.使用0.5%、1%、1.5%的戊二醛溶液固定细胞后再漂洗,变换原子力显微镜的扫描模式,调节扫描参量并在大气环境下观测以寻找该环境下的最佳成像条件;将用多聚赖氨酸处理基底后的培养细胞直接放置于生理溶液中用原子力显微镜进行溶液环境观测,比较扫描时限并分别改变环境液体类型、探针以及扫描频率,比较了不同条件下原子力显微镜图像的差异,在得出最优参量的同时对其相关原理进行了分析,建立了活细胞实时观测的实验方法.比较两种条件下的细胞图像发现,戊二醛溶液固定过的细胞与生理溶液环境中的活细胞有很大差别,在生理溶液条件下的细胞饱满,可见到光滑清晰的细胞边缘;但戊二醛溶液固定的细胞表面粗糙,细胞边缘不清晰,表明固定后观测到的细胞与生理状态下活细胞的表面形貌存在很大差异. 相似文献
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Since RGD peptides (R: arginine; G: glycine; D: aspartic acid) are found to promote cell adhesion, they are modified at numerous materials surface for medical applications such as drug delivery and regenerative medicine. Peptide-cell surface interactions play a key role in the above applications. In this letter, we study the adhesion force between the RGD-coated bead and Hela cell surface by optical tweezes. The adhesion is dominated by the binding of α5β1 and RGD-peptide with higher adhesion probability and stronger adhesion strength compared with the adhesion of bare bead and cell surface. The binding force for a single α5β1 -GRGDSP pair is determined to be 16.8 pN at a loading rate of 1.5 nN/s. The unstressed off-rate is 1.65 × 10-2s-1 and the distance of transition state for the rigid binding model is 3.0 nm. 相似文献
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WangJufang WeyratherWilma 《近代物理研究所和兰州重离子加速器实验室年报》2003,(1):81-81
In order to investigate the fractional effect, normal human fibroblasts GM5758 were irradiated with oneand two fractional X-rays. After irradiation, cell survival was performed by standard methods. Cell terminal differentiation pattern was determined as mitotic fibroblasts (MF) Ⅰ, Ⅱ and Ⅲ, post mitotic fibroblasts (PMF) Ⅳ, Ⅴ and Ⅵ, according to cellular morphology, as described by C. Fournier. As show in Fig.l, the survival fraction of two-fraction irradiation is higher than that of one-fraction irradiation. This result suggests that sub-lethal damage induced by radiation can be repaired efficiently for fractional irradiation. As for differentiation 相似文献
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