The organic-inorganic hybrid perovskite CH3NH3PbI3 is a novel light harvester, which can greatly improve the solar-conversion efficiency of dye-sensitized solar cells. In this article, a first-principle theoretical study is performed using local, semi-local and non-local exchange-correlation approximations to find a suitable method for this material. Our results, using the non-local optB86b + vdWDF functional, excellently agree with the experimental data. Thus, consideration of weak van der Waals interactions is demonstrated to be important for the accurate description of the properties of this type of organic-inorganic hybrid materials. Further analysis of the electronic properties reveals that I 5p electrons can be photo-excited to Pb 6p empty states. The main interaction between the organic cations and the inorganic framework is through the ionic bonding between CH3 and I ions. Furthermore, I atoms in the Pb-I framework are found to be chemically inequivalent because of their different chemical environments.

Long noncoding RNAs (lncRNAs) have been investigated as a new class of regulators of cellular processes, such as cell growth, apoptosis, and carcinogenesis. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has recently been identified to be involved in tumorigenesis of several cancers such as lung cancer, pancreatic cancer, and cervical cancer. However, the role of lncRNA MALAT1 in clear cell renal cell carcinoma (ccRCC) remains unclear. Expression levels of lncRNA MALAT1 in ccRCC tissues and renal cancer cell lines were evaluated by quantitative real-time PCR (qRT-PCR), and its association with overall survival of patients was analyzed by statistical analysis. Small interfering RNA (siRNA) was used to suppress MALAT1 expression in renal cancer cells. In vitro assays were conducted to further explore its role in tumor progression. The expression level of MALAT1 was higher in ccRCC tissues and renal cancer cells compared to adjacent non-tumor tissues and normal human proximal tubule epithelial cells HK-2. The ccRCC patients with higher MALAT1 expression had an advanced clinical features and a shorter overall survival time than those with lower MALAT1 expression. And multivariate analysis showed that the status of MALAT1 expression was an independent predictor of overall survival in ccRCC. Additionally, our data indicated that knockdown expression of MALAT1 decreased renal cancer cell proliferation, migration, and invasion. Our data suggested that lncRNA MALAT1 was a novel molecule involved in ccRCC progression, which provided a potential prognostic biomarker and therapeutic target.

As am etal-free nitrogen reduction reaction (NRR) photocatalyst, g-C 3 N 4 is available from as calable synthesis at low cost. Importantly,i tc an be readily functionalizedt o enhance photocatalytic activities.H owever,t he use of g-C 3 N 4based photocatalysts for the NRR has been questioned because of the elusive mechanism and the involvement of Nd efects. This work reports the synthesis of ag -C 3 N 4 photocatalyst modified with cyano groups and intercalated K + (mCNN), possessing extended visible-light harvesting capacity and superior photocatalytic NRR activity (NH 3 yield: 3.42 mmol g À1 h À1 ). Experimental and theoretical studies suggest that the -C Ni nm CNN can be regenerated through ap athway analogous to Mars van Krevelen process with the aid of the intercalated K + .T he results confirm that the regeneration of the cyano group not only enhances photocatalytic activity and sustains the catalytic cycle,b ut also stabilizes the photocatalyst.