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This paper presents a study on the photovoltaic effect of a graphene/MoS2/Si double heterostructure, grown by rapid chemical vapor deposition. It was found that the double junctions of the graphene/MoS2 Schottky junction and the MoS2/Si heterostructure played important roles in enhancing the device's performance. They allowed more electron-hole pairs to be efficiently generated, separated, and collected in the graphene/MoS2/Si double interface. The device demonstrated an open circuit voltage of 0.51 V and an energy conversion efficiency of 2.58% under an optical illumination of 500 mW/cm2. The photovoltaic effect of the device was partly attributed to the strong light absorption and photoresponse of the few-layer MoS2 film, and partly ascribed to the high carrier-collection-rate of the double van der Waals heterostructures (vdWHs) in the device. [ABSTRACT FROM AUTHOR]

Epigenetic modifications are important mechanisms responsible for cancer progression. Accumulating data suggest that (−)-epigallocatechin-3-gallate (EGCG), the most abundant catechin of green tea, may hamper carcinogenesis by targeting epigenetic alterations. We found that signal peptide-CUB (complement protein C1r/C1s, Uegf, and Bmp1)-EGF (epidermal growth factor) domain-containing protein 2 (SCUBE2), a tumor suppressor gene, was hypermethylated in breast tumors. However, it is unknown whether EGCG regulates SCUBE2 methylation, and the mechanisms remain undefined. This study was designed to investigate the effect of EGCG on SCUBE2 methylation in breast cancer cells. We reveal that EGCG possesses a significantly inhibitory effect on cell viability in a dose- and time-dependent manner and presents more effects than other catechins. EGCG treatment resulted in enhancement of the SCUBE2 gene, along with elevated E-cadherin and decreased vimentin expression, leading to significant suppression of cell migration and invasion. The inhibitory effect of EGCG on SCUBE2 knock-down cells was remarkably alleviated. Further study demonstrated that EGCG significantly decreased the SCUBE2 methylation status by reducing DNA methyltransferase (DNMT) expression and activity. In summary, this study reported for the first time that SCUBE2 methylation can be reversed by EGCG treatment, finally resulting in the inhibition of breast cancer progression. These results suggest the epigenetic role of EGCG and its potential implication in breast cancer therapy. [ABSTRACT FROM AUTHOR]