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Objective To investigate the molecular mechanism by which the circadian clock gene Period2 (PER2) downregulates extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) phosphorylation levels in nasopharyngeal carcinoma (NPC). Methods Cells were infected with lentivirus to construct cell lines. The expression of PER2 protein was validated using label-free proteomic analysis. Different concentrations of the ERK pathway activator Ceramide C6 were used to intervene with the cells, and the optimal drug concentration and treatment time were determined based on cell proliferation assessed by MTT assay. Western blotting was performed to detect the expression of PER2, ERK, p38 MAPK, p-ERK, and p-p38 MAPK proteins in cells after intervention with Ceramide C6, with the normal control group treated with an equal amount of drug solvent. Flow cytometry was used to analyze the cell cycle, and Transwell assay was conducted to evaluate cell invasion ability, further elucidating the mechanism by which PER2 regulates ERK and MAPK phosphorylation. Immunohistochemistry was employed to detect the expression of PER2 and p-ERK proteins in human NPC samples, and the correlation between PER2, p-ERK expression, and clinical characteristics of NPC was analyzed. Results Proteomic analysis showed that the expression of PER2 protein was significantly higher in the PER2 overexpression (OE) group compared to the negative virus control group and blank control group (P＜0.05). The top 20 differentially expressed proteins revealed that MAPK3 exhibited significant differences between the PER2 OE group and control group (P＜0.05). MTT assay results indicated that the optimal drug concentration was 10 μM, with the optimal treatment time being 24 hours. Western blotting results showed that PER2 overexpression downregulated the expression of p-ERK and p-p38 MAPK proteins, and intervention with Ceramide C6 led to upregulation of p-ERK and p-p38 MAPK protein expression levels in the PER2-OE group, with significant differences before and after intervention (P＜0.01). Cell cycle analysis revealed that intervention with Ceramide C6 increased the proportion of cells in the G1 phase and decreased the number of cells in the G2 phase. Transwell assay results demonstrated that PER2 overexpression inhibited cell invasion ability, which could not be reversed by kinase. Immunohistochemistry showed significant differences in the expression rates of PER2 and p-ERK proteins in NPC tissues and nasopharyngeal mucosa (P＜0.05). The expression of PER2 protein was correlated with tumor T stage (P＜0.05) and positively correlated with p-ERK protein expression in NPC tissues (P＜0.05). Conclusion PER2 overexpression downregulates ERK/MAPK phosphorylation levels, possibly not by directly affecting the phosphorylation sites of ERK and p38 MAPK, but by regulating key nodes of ERK and p38 MAPK. PER2 protein is downregulated and p-ERK protein is upregulated in NPC tissues, and they are correlated, closely related to the occurrence and development of tumors. [ABSTRACT FROM AUTHOR]

The influence of the cell wall material strain hardening effect on the deformation mode and cushioning properties of regular hexagonal honeycomb under in-plane impact loadings was investigated by numerical simulation. In order to quantify the strain hardening effect of the cell wall material, hardening parameter. E is defined. By keeping the honeycombs' configuration parameters were fixed and setting different loading velocities,the finite element models of honeycomb specimens with different values of E were established. Then a great deal of simulation calculations were performed and the related deformation mode and responses curves were obtained. These results showed that there are three kinds of deformation modes, such as X-shape,V-shape and l-shape with the increase of the impact velocity,and the deformation tends to be homogenized caused by the strain hardening effect of the cell wall material. The stress-strain curve,dynamic peak stress curve and energy absorption curve of the honeycomb core were also obtained by post-processing. Based on these mechanical response curves,we can conclude that honeycomb plateau stress and energy absorption would increase because of the strain hardening effect of the cell wall material. But this influence would be restrained with the increase of the impact velocity. [ABSTRACT FROM AUTHOR]

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Copyright of Shandong Medical Journal is the property of Shandong Medical Health Newspapers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

OBJECTIVE: To probe into the clinical efficacy of magnesium sulfate combined with low-dose aspirin in treatment of pregnancy-induced hypertension. METHODS: 100 patients with pregnancy-induced hypertension admitted from Aug. 2014 to Aug. 2015 were selected to be divided into control group and observation group via the random number table, with 50 cases in each. The control group were treated with 25% intravenous infusion of magnesium sulfate in 1-1.5 g per hour, 20 g for a day; the observation group additionally received oral aspirin based on the control group, 50 mg for a day. After treatment of 3 d, the efficacy, related laboratory indicators and adverse drug reactions in two groups were observed . RESULTS: The total effective rate of observation group was 94.00% (47/50), significantly higher than that in the control group 60.00% (30/50), the difference was statistically significant (P <0.05). After treatment, the blood viscosity, hematocrit, urinary protein excretion, peak-to-valley ratio of umbilical artery blood flow velocity and vascular resistance indicators of umbilical artery in observation group had been significantly improved compared with before treatment, and the improvement degree was better than that of control group, with statistically significant difference (P<0.05). The incidence of adverse drug reactions was 16.00%(8/50), significantly lower than that of control group 44.00% (22/50), with statistically significant difference (P<0.05) .CONCLUSIONS: The effects of magnesium sulfate combined with low-dose aspirin in treatment of pregnancy-induced hypertension is remarkable, which can significantly improve the clinical symptoms in patients with high safety. It is worthy of clinical application and promotion. [ABSTRACT FROM AUTHOR]