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Special vehicles named flat transporters are used to deliver heavy ship assembly blocks in shipyards. Because each movement of assembly blocks among workshops needs transporters and the transportations are time-consuming, the scheduling of transporters is important for maintaining the overall production schedule of assembly blocks. This paper considers an optimization transporter scheduling problem for assembly blocks. The objective is to minimize logistics time, which includes empty travel time of transporters and waiting time and delay time of block tasks. Considering time windows of ship blocks, carrying capacity of transporters, and precedence relationships of tasks, a mathematical model is proposed. A hybrid topological graph is used to denote precedence and cooperating relationships of tasks. A metaheuristic algorithm based on the hybrid topological graph and genetic algorithm and Tabu search is proposed. The performance of the algorithm was evaluated by comparing the algorithm to optimal result in small-sized instances and several strategies in large-sized instances. The results showed the efficiency and effectiveness of the proposed algorithm.

The aim of this study was to investigate the effects of capsaicin on migration and invasion of breast cancer MDA-MB-231 cells and its possible mechanism. The MDA-MB-231 cells were incubated in the medium containing different concentrations of capsaicin for 24 h. CCK-8 assay was employed to detect the cell viability. The cell migration and invasion were assessed by wound healing assay and transwell invasion assay, respectively. The protein levels of c-Src, p-c-Src (Tyr416), FAK, p-FAK (Tyr576), Paxillin, p-Paxillin (Tyr118), matrix metalloproteinase 2 (MMP2) and MMP9 in the MDA-MB-231 cells were detected by Western blotting. The mRNA expressions of MMP2 and MMP9 were measured by RT-PCR. The result showed that capsaicin (25 and 50 μmol/L) remarkably reduced the abilities of migration and invasion (P0.05), inhibited the phosphorylation of c-Src, FAK and Paxillin (P0.05), and down-regulated MMP2 and MMP9 expressions at mRNA and protein levels (P0.05) in MDA-MB-231 cells. These effects of capsaicin were all in dose-dependent manners. These results suggest that capsaicin may suppress the migration and invasion of breast cancer MDA-MB-231 cells by inhibiting the phosphorylations of c-Src, FAK and Paxillin, and down-regulating the mRNA and protein levels of MMP2 and MMP9.

The aim of this study was to investigate the effects of digoxin on the chemoresistance of human breast cancer cell line MCF-7/adriamycin (ADR) and its underlying mechanism. MCF-7 and MCF-7/ADR cells were designated as control and ADR groups, respectively. MCF-7/ADR cells in ADR + digoxin group received 48 h of digoxin (10 nmol/L) treatment; MCF-7/ADR cells transfected with pLKO.1-shHIF-1α and pLKO.1-shcontrol plasmids were named shHIF-1α and shcontrol groups, respectively. CCK-8 assay was employed to detect the cytotoxic effect of ADR on MCF-7/ADR cells, and IC50 value and resistance index were calculated according to CCK-8. RT-PCR was used to measure the mRNA levels of hypoxia inducible factor-1α (HIF-1α) and multidrug resistance-1 (MDR1). Western blot was used to analyze the protein levels of HIF-1α and MDR1. Flow cytometry was used to determine the apoptosis. The result showed that the resistance index of MCF-7/ADR cells was 115.6, and it was reduced to 47.2 under the action of digoxin (P0.05). In comparison with control group, ADR groups showed increased protein and mRNA levels of HIF-1α and MDR1 (P0.05). Digoxin reduced the protein levels of HIF-1α and MDR1, as well as the mRNA level of MDR1, but did not affect the mRNA level of HIF-1α. After HIF-1α gene was silenced, the protein levels of HIF-1α and MDR1 were down-regulated (P0.05), and the pro-apoptotic effect of ADR on MCF-7/ADR cells was enhanced. Although it was also observed that digoxin promoted cell apoptosis in both shcontrol and shHIF-1α groups, the difference between the two groups was not significant. In conclusion, the results suggest that digoxin may partially reverse the ADR resistance in human breast cancer cell line MCF-7/ADR by means of down-regulating the expression levels of HIF-1α and MDR1 and promoting apoptosis via HIF-1α-independent pathway.