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Objective To investigate whether dihydrotanshinone Ⅰ could regulate the biological activities of proliferation, migration and apoptosis of esophageal squamous cell carcinoma cell line EC9706 through Wnt/β-catenin signaling pathway. Methods EC9706 cells were cultured in medium containing 0, 10, and 30 μmol/L dihydrotanshinoneⅠ solution, and cell proliferation was examined with a cell counting kit-8, cell migration was checked with scratch test. Western blot was used to detect β-catenin, cyclin D1 and c-myc protein expression in cells. Apoptosis was detected by flow cytometry. Results DihydrotanshinoneⅠ effectively inhibited the proliferation and migration of EC9706 cells. DihydrotanshinoneⅠ down-regulated β-catenin, cyclin D1 and c-myc protein expression in cells (P＜0.05). DihydrotanshinoneⅠ promoted apoptosis in a dose-dependent manner. Conclusions DihydrotanshinoneⅠ can inhibit proliferation and migration of EC9706 cells and promote the cells apoptosis.

In this paper, we focus on the investigations on the stochastic stability and the stochastic resonance (SR) phenomena for a FitzHugh-Nagumo system with time delay induced by a multiplicative non-Gaussian colored noise and an additive Gaussian colored noise. By use of the fast descent method, the unified colored noise approximation and the two-state theory for the SR, the stationary probability density function (SPDF) and the signal-to-noise ratio (SNR) caused by different noise terms and time delay are explored. The investigation results indicate that the two noise intensities, time delay and the departure parameter from the Gaussian noise can all reduce the probability density around the two stable states and destroy the stability of the neural system; while the two noise correlation times τ and τ 0 can both improve the probability density around both stable states and reinforce the biological stability of the neural system. As regards the SNR, it is found that the two noise intensities and the departure coefficient can all weaken the SR effect, while time delay α and the correlation time τ of the multiplicative noise will always magnify the SR phenomenon. It is worth to mention that the correlation time τ 0 of the additive noise can stimulate the SR effect, but not alter the maximum of the SNR. [ABSTRACT FROM AUTHOR]

Damages caused by the effects of cyclic loading (fatigue) and high temperature (creep and oxidation) have been considered critical and need to be appropriately evaluated. A series of strain‐controlled fatigue and creep‐fatigue tests are performed on P92 at 873 K under oxygen‐containing environment. The creep‐fatigue life prediction results are summarized using models based on strain‐range partition, Manson–Coffin equation and linear damage summation (LDS) rule. Obviously, the models based on the LDS rule show relatively good performance with an error band of ±2.5. In view of the adverse effects of oxidation on creep‐fatigue endurance, this paper further develops a physically‐based oxidation damage equation, which is incorporated into LDS rule for the improvement of life assessment. The predicted and experimental results falling into ±1.5 error band proved the accuracy of the proposed oxidation damage equation in the LDS rule. Additionally, model selection criteria are recommended to evaluate the model prediction capabilities. Highlights: A series of fatigue, creep‐fatigue, and oxidation tests are performed on P92 at 873 K.Oxidation damage equation based on kinetics and concentration distribution is proposed.Error band is reduced from ±2.5 to ±1.5 by using the proposed oxidation damage equation.W‐SEDE‐O model performs best with the minimum error band & best statistical indicators. [ABSTRACT FROM AUTHOR]

In this paper, the regime shift behaviors between the prosperous state and the extinction state and stochastic resonance (SR) phenomenon for a metapopulation system subjected to time delay and correlated Gaussian colored noises are investigated. Through the numerical calculation of the modified potential function and the stationary probability density function (SPDF), one can make clearly the following results: Both multiplicative noise and noise correlation times can improve effectively the ecological stability and prolong the survival time of the system; while additive noise, time delay and noise correlation strength can weaken significantly the biological stability and speed up the extinction of the population. As for the signal-to-noise ratio (SNR), it is found that time delay, multiplicative noise and noise correlation strength can all impair the SR effect. Conversely, the two noise correlation times and additive noise are in favor of the improvement of the peak values of SNR. It is particularly worth mentioning that in the case of M = 0. 0 3 , time delay α and self-correlation time τ 2 of the additive noise display exactly the opposite effect on the stimulation of the resonant peak in the SNR– λ plots. [ABSTRACT FROM AUTHOR]