Improved light extraction in all-inorganic perovskite light-emitting devices with periodic nanostructures by nanoimprinting lithography.

We report an improved light extraction in all-inorganic perovskite light-emitting devices (PeLEDs) by integrating a periodic corrugated nanostructure at the metallic cathode/organic interface. Nanoimprinting lithography was used to introduce the nanostructures onto the surface of the electron transport layer directly to avoid influencing the morphology and crystallinity of the perovskite film underneath. The trapped energy at the metallic electrode has been successfully outcoupled by the excitation of the surface plasma polariton (SPP) modes induced by the periodic corrugations. The luminance and current efficiency of the periodically corrugated PeLED exhibit enhancements of 42% and 28%, respectively, compared to those of the planar PeLED. The finite-difference time-domain simulation was used to confirm the efficient outcoupling of the SPP modes.

SIRT7 Exhibits Oncogenic Potential in Human Ovarian Cancer Cells.

BACKGROUND: Sirtuin7 (SIRT7) is a type of nicotinamide adenine dinucleotide oxidized form (NAD+)-dependent deacetylase and the least understood member of the sirtuins family; it is implicated in various processes, such as aging, DNA damage repair and cell signaling transduction. There is some evidence that SIRT7 may function as a tumor trigger for human malignancy. Here, we aimed to explore the biological function of SIRT7 in ovarian carcinoma cells and its potential mechanism. MATERIALS AND METHODS: Expression of SIRT7 in ovarian cancer cell lines was detected by western blotting. Transduced cell lines with SIRT7 knockdown or overexpression were constructed. Cell viability, cologenic, apoptosis-associated and motility assays were performed to elucidate the biological function of SIRT7 in ovarian cancer cells. RESULTS: SIRT7 demonstrated a higher level in ovarian cancer cell lines compared with normal cells. On the one hand, down-regulation of SIRT7 significantly reduced ovarian cancer cell growth, repressed colony formation and increased cancer cell apoptosis; on the other hand, up-regulation promoted the migration of cancer cells. Additionally, repression of SIRT7 also induced change in apoptosis-related molecules and subunits of the NF-κB family. CONCLUSIONS: In the present study, our data indicated that SIRT7 might play a role of oncogene in ovarian malignancy and be a potential therapeutic target.

DNA methylation of human telomerase reverse transcriptase associated with leukocyte telomere length shortening in hyperhomocysteinemia-type hypertension in humans and in a rat model.

BACKGROUND: Elevated homocysteine (Hcy) levels might play a role in the development of essential hypertension (EH). Telomere dynamics provide valuable insight into the pathogenesis of age-related diseases. The contribution of Hcy to leukocyte telomere length (LTL) shortening in EH and the underlying mechanism was examined. METHODS AND RESULTS: LTL (ratio of the copy number of telomere [T] repeats to that of a single [S] gene, T/S ratio) was inversely associated with age in patients with EH (n=258) and healthy controls (n=137), but significantly decreased with the Hcy level only in patients with hypertension after adjustment for age and sex. Age, hypertension and levels of Hcy and low-density lipoprotein combined contributed to LTL shortening; an increased serum folate level could reverse the Hcy effect seen on multivariate regression analysis. In addition, qPCR and methylation-specific PCR assay revealed that LTL shortening and mRNA expression and the methylation ratio of human telomerase reverse transcriptase (hTERT) were lower in patients with EH than in controls, and gradually decreased with increasing Hcy level, but not with blood pressure, in EH patients (Ptrend<0.0001, 0.004 and 0.012, respectively). Furthermore, Hyperhomocysteinemia, but not hypertension, promoted telomerase reverse transcriptase DNA hypomethylation and reduced mRNA levels, which contributed to shortened LTL in the hypertension rat model. CONCLUSIONS: Elevated Hcy but not hypertension was related to hTERT DNA hypomethylation and reduced mRNA level, thus contributing to the shortening of LTL hypertension.