ABSTRACT
Enhancing charge separation in semiconductor photocatalysts is a major challenge for efficient artificial photosynthesis. Herein, a compact heterojunction is designed by embedding half-metallic C(CN)3 (hm-CN) hydrothermally in BiOBr (BOB) as the backbone. The interface between hm-CN and BOB is seamless and formed by covalent bonding to facilitate the transmission of photoinduced electrons from BOB to hm-CN. The transient photocurrents and electrochemical impedance spectra reveal that the modified composite catalyst exhibits a larger electron transfer rate. The photocatalytic activity of hm-CN/BOB increases significantly as indicated by a CO yield that is about four times higher than that of individual components. Density-functional theory calculations verify that the heterojunction improves electron transport and decreases the reaction energy barrier, thus promoting the overall photocatalytic CO2 conversion efficiency. The half-metal nitride coupled semiconductor heterojunctions might have large potential in artificial photosynthesis and related applications.
ABSTRACT
Water pollution is a significant social issue that endangers human health. The technology for the photocatalytic degradation of organic pollutants in water can directly utilize solar energy and has a promising future. A novel Co3O4/g-C3N4 type-II heterojunction material was prepared by hydrothermal and calcination strategies and used for the economical photocatalytic degradation of rhodamine B (RhB) in water. Benefitting the development of type-II heterojunction structure, the separation and transfer of photogenerated electrons and holes in 5% Co3O4/g-C3N4 photocatalyst was accelerated, leading to a degradation rate 5.8 times higher than that of pure g-C3N4. The radical capturing experiments and ESR spectra indicated that the main active species are â¢O2- and h+. This work will provide possible routes for exploring catalysts with potential for photocatalytic applications.
ABSTRACT
On Earth's surface, there are only a handful of high-quality astronomical sites that meet the requirements for very large next-generation facilities. In the context of scientific opportunities in time-domain astronomy, a good site on the Tibetan Plateau will bridge the longitudinal gap between the known best sites1,2 (all in the Western Hemisphere). The Tibetan Plateau is the highest plateau on Earth, with an average elevation of over 4,000 metres, and thus potentially provides very good opportunities for astronomy and particle astrophysics3-5. Here we report the results of three years of monitoring of testing an area at a local summit on Saishiteng Mountain near Lenghu Town in Qinghai Province. The altitudes of the potential locations are between 4,200 and 4,500 metres. An area of over 100,000 square kilometres surrounding Lenghu Town has a lower altitude of below 3,000 metres, with an extremely arid climate and unusually clear local sky (day and night)6. Of the nights at the site, 70 per cent have clear, photometric conditions, with a median seeing of 0.75 arcseconds. The median night temperature variation is only 2.4 degrees Celsius, indicating very stable local surface air. The precipitable water vapour is lower than 2 millimetres for 55 per cent of the night.
ABSTRACT
BACKGROUND: Long non-coding RNAs (LncRNAs) are broadly transcribed in the genome of human and animals, they play critical roles in cellular process, and participate in the progression of multiple diseases, including cancer. SLC16A1-AS1 is a tumor suppressive lncRNA in lung cancer. This study aimed to investigate the involvement of lncRNA SLC16A1-AS1 in hepatocellular carcinoma (HCC). METHOD: A total of 64 HCC patients were subjected to biopsy to obtain paired HCC and non-tumor tissues. Expression of SLC16A1-AS1 and miR-141 in paired tissues was determined by RT-qPCR. Correlations were analyzed by linear regression. Overexpression of SLC16A1-AS1 and miR-141 were achieved in HCC cells to explore the interactions between them. The methylation of the gene encoding miR-141 in HCC cells was detected by methylation-specific PCR (MSP). CCK-8 assay was performed for cell proliferation assay. RESULTS: SLC16A1-AS1 was upregulated in HCC and its high expression levels predicted poor survival of HCC patients. Expression levels of miR-141 were lower in HCC patients and were inversely correlated with the expression levels of SLC16A1-AS1. In HCC cells, overexpression of SLC16A1-AS1 led to downregulation of miR-141, while overexpression of miR-141 did not regulate the expression of SLC16A1-AS1. In addition, overexpression of SLC16A1-AS1 led to increased methylation of miR-141. And overexpression of SLC16A1-AS1 attenuated the inhibitory effects of miR-141 on HCC cell proliferation. CONCLUSION: SLC16A1-AS1 is upregulated in HCC and predicts poor survival. In addition, SLC16A1-AS1 may downregulate miR-141 through methylation to promote cancer cell proliferation.
