No abstract

A novel perovskite solar cell-TiO2@BiVO4 photoelectrochemical system for direct solar water splitting shows an overall solar-to-hydrogen efficiency of 1.24%.

The chemoresistance of lung cancer is a significant contributor to its high mortality and morbidity rate. There is an urgent need to identify differentially expressed genes in lung cancer patients with a poor prognosis to develop effective means to overcome drug resistance in subsequent treatment. In this study, we identified the secreted phosphoprotein 1 (SPP1) as a potential gene associated with a poor diagnosis of lung cancer patients using the Cancer Genome Atlas analysis, which suggested that the expression of SPP1 in tumor tissues was significantly higher than normal tissues. The high expression of SPP1 was also correlated with tumor grade and poor clinical prognosis. To understand the roles of SPP1 and the DNA methyltransferase 1 (DNMT1), which regulated SPP1 expression, in affecting cell viability, migration and invasion, SPP1 and DNMT1 were overexpressed in the human lung cancer A549 and NCI-446 cells, followed by analyzing cell viability, migration and invasion. We showed that SPP1 promoted the proliferation, migration and invasion of lung cancer cells, and increased the resistance of lung cancer to the chemotherapeutic drug cisplatin. Knocking down SPP1 in cells restored sensitivity to cisplatin. Further, A549 cells without SPP1 overexpression demonstrated lower tumor growth rate than SPP1 overexpression cells using the xenograft tumor mouse model. High expression of SPP1 in lung cancer tumor tissue was caused by the reduced methylation level of its promoter region mediated by DNMT1. Our data suggested that SPP1 can be used as a marker for highly malignant lung cancer and targeting SPP1 may be a potential lung cancer treatment strategy.

Antisolvent method has been widely applied to fabricate hybrid halide perovskite solar cells. However, the quality of perovskite film is unable to effectively control for the excessively fast crystallization. In this work, we investigated the effect of precursor concentration and spinning speed as well as additive CH 3 NH 3 Cl on quality perovskite film and thus the performance solar cells. The growth of crystal toward the orientation parallel to the direction of facet (002)/(004) slows down as the concentration and spinning speed increases. The lattice constants points out the expansion of crystal size in the direction along the c-axis of around 0.04 Å due to the size difference between I and Cl ions. A vertical growth mechanism was proposed to elaborate the crystallite growth of CH 3 NH 3 PbI 3 (Cl) perovskite film. Consequently, the perovskite solar cell efficiency impressively increases from ∼12% to ∼16% along enlarging the crystal size. Various advanced characterization techniques including ultrafast spectroscopy and electronic impedance spectroscopy elucidated that an optimal film with large grain size and less defect states could result in the enhancement of charge transport and collection efficiency.