No abstract

Mine fires mainly arise from spontaneous combustion of coal seams and are a global issue that has attracted increasing public attention. Particularly in china, the closure of coal workfaces because of spontaneous combustion has contributed to substantial economic loss. To reduce the occurrence of mine fires, the spontaneous coal combustion underground needs to be studied. In this paper, a computational fluid dynamics (CFD) model was developed for coal spontaneous combustion under goaf gas drainage conditions. The CFD model was used to simulate the distribution of oxygen in the goaf at the workface in a fully mechanized cave mine. The goaf was treated as an anisotropic medium, and the effects of methane drainage and oxygen consumption on spontaneous combustion were considered. The simulation results matched observational data from a field study, which indicates CFD simulation is suitable for research on the distribution of oxygen in coalmines. The results also indicated that near the workface spontaneous combustion was more likely to take place in the upper part of the goaf than near the bottom, while further from workface the risk of spontaneous combustion was greater in the lower part of the goaf. These results can be used to develop firefighting approaches for coalmines.

Background: Prognostic biomarkers remain a focus in colorectal cancer during last decades. There are some studies of E2F transcription factors in different cancer. But the utility of E2F transcription factors as cancer biomarkers in colorectal cancer has not been confirmed. In this research we analyzed multiple databases and performed experimental validation of E2Fs as biomarkers. Methords: Bioinformatics analysis was the main part of this research. Besides, IHC was used to the huamn normal and tumor tissues.Results: Our study showed that the mRNA expression levels of E2F1/3/4/5/6/7/8 were significantly upregulated in carcinoma tissues, whereas E2F2 mRNA was downregulated. High E2F3/4 expression correlated with poor prognosis, whereas high E2F2 expression was correlated with good prognosis. Pathological parameters indicated that expression levels of E2F1/3/5 varied in different tumor stages; however, expression of E2F2/4/6/7/8 did not vary with tumor stage. E2F4 expression was higher in men than women. For pathological type, E2F8 expression was higher in the mucinous adenocarcinoma group compared with the adenocarcinoma group. E2F expression levels were altered in 175 of 524 patients (33%) with colorectal cancer, and the alterations of E2Fs in mucinous adenocarcinoma were more frequent than in adenocarcinoma. Cell cycle was the core function and the most enriched pathway of E2Fs. The functions of E2F2/3/4 may be regulated by some miRNAs. Conclusions: We proved that E2F2/3/4 can be used as prognostic biomarkers for colorectal cancer, and E2F2/3/4 mRNAs may be targeted by some miRNAs to influence “CELL CYCLE” pathway and exert their core functions in colorectal cancer.