Two-Dimensional Lead-Free Double Perovskite with Superior Stability and Optoelectronic Properties for Solar Cell Application

2D Dion–Jacobson (DJ) perovskites have recently drawn much attention due to their superior charge transport and high environmental stability. Unfortunately, the issue of toxicity regarding the Pb element in perovskites has yet to be solved. Herein, we propose a new BDA2CuBiI8 (1,4-butanediamine) 2D perovskite by substituting two Pb2+ with the pair of Cu+ and Bi3+ to achieve Pb-free halide perovskites. The first-principles calculations demonstrated the thermodynamic and dynamic stabilities of 2D BDA2CuBiI8. Furthermore, the results indicate that this new material has a direct band gap of 1.58 eV suitable for solar cells with a theoretical maximal efficiency over 30% and allows direct transitions between band edges contrary to its bulk counterpart. The interlayer interaction of apical I–I is found to play a crucial role in determining the band edges. The findings indicate DJ structure type and double substitution together provide a new method for designing lead-free perovskites for efficient solar cells

Generation of Phenol and Molecular Hydrogen through Catalyst-Free C–H Activation of Benzene by Water Radical Cations

Here, we report on the abundant formation of phenol and molecular hydrogen when benzene vapor was exposed to gas plasma generated by +5.5 kV corona discharge of water vapor in argon in the absence of oxygen. Systematic analysis using a series of isotopic standards (d6-benzene, D2O, and H218O) and benzene derivatives (mono-, di-, trichlorobenzene, and N,N-dimethylaniline) indicated that the formation of phenol occurred through the reaction between neutral benzene and the radical cation of water dimer, (H2O)2+•. A two-step reaction mechanism was proposed based on the results of experiments and DFT calculations: (1) the formation of (C6H6...H2O)+• intermediate through electrophilic addition; (2) the formation of C6H5OH+• through the release of H2 from the (C6H6...H2O)+• intermediate. Our findings offer a novel catalyst-free method to prepare phenol from benzene with phenol selectivity >90%

Nitrogen Fixation by Benzene into Pyridine and Aniline in Water/Nitrogen Plasma

We demonstrated direct conversion of benzene into pyridine and aniline, assisted through exact mass measurements (m/z 80.0494, 93.0574, and 94.0651, respectively), through the interaction of benzene with water/nitrogen vapor plasma produced by corona discharge. Systematic analysis using a series of isotopic standards indicated that formation of pyridine and aniline occurred through the reaction between neutral benzene and reactive N+(OH2)2 in water/nitrogen plasma; exact mass measurements of products and intermediates supported this hypothesis. As the proportion of water vapor in plasma increased over time, the reaction proceeded from exclusive formation of protonated pyridine to formation of protonated aniline as the main product; theoretical simulations indicated that the presence of water vapor promoted proton migration to elicit formation of protonated aniline. The reactions we discovered suggest a new mechanism for direct nitrogen fixation

The expression of COX-2 and EP2 in HCC cells and meloxicam reduces cell viability <i>in vitro</i>.

<p>(A) The expression of COX-2 in HCC cell lines SMMC-7402, Bel-7402, HepG2, SMMC-7721 and Huh-7 was detected by Western Blotting. GAPDH served as an internal control. (B) Bel-7402, HepG2 and SMMC-7721 cells that express higher levels of COX-2 were incubated with increasing concentrations of meloxicam, and the rates of viability inhibition were measured. (C) The expression of EP2 in the above five HCC cell lines was detected by Western Blotting. GAPDH served as an internal control.</p

Meloxicam Executes Its Antitumor Effects against Hepatocellular Carcinoma in COX-2- Dependent and -Independent Pathways

<div><p>Background</p><p>Cyclooxygenase (COX)-2 is overexpressed in many types of cancers including hepatocellular carcinoma (HCC). Meloxicam, a selective COX-2 inhibitor, has shown potential therapeutic effects against HCC, but the mechanisms accounting for its anti-cancer activities remain unclear.</p><p>Methods and Findings</p><p>Meloxicam inhibited the ability of human HCC cells expressing higher levels of COX-2 to migrate, invade, adhere and form colonies through upregulating the expression of E-cadherin and downregulating the expression of matrix metalloproteinase (MMP) -2. Meloxicam induced cell apoptosis by upregulating pro-apoptotic proteins including Bax and Fas-L, and downregulating anti-apoptotic proteins including survivin and myeloid cell leukemia-1 (Mcl-1), through inhibiting phosphorylation of AKT. Addition of prostaglandin E2 (PGE2), the major product of COX-2, could abrogate the effects of meloxicam on the expression of survivin and myeloid cell leukemia-1 (Mcl-1), but not Bax and Fas-L, indicating that meloxicam induces cell apoptosis via both COX-2-dependent and -independent pathways. Meloxicam also induced cell autophagy by upregulating Beclin 1 and light chain 3-II. Specific inhibition of autophagy by 3-methyladenine and chloroquine had little effect on cell apoptosis but could enhance the pro-apoptotic effects of meloxicam by further upregulating the expression of Bax.</p><p>Conclusions</p><p>Meloxicam executes its antitumor effects by targeting the COX-2/MMP-2/E-cadherin, AKT, apoptotic and autophagic pathways in COX-2-dependent and -independent pathways, and inhibition of cell autophagy could help to overcome the resistance to meloxicam-induced apoptosis in HCC.</p></div

Meloxicam inhibits cell migration, invasion, adhesion and colony formation.

<p>(A) Representative photographs were taken from HepG2 cells incubated for 48 h with meloxicam (80 μM) or vehicle (control) and subjected to cell migration, invasion, adhesion and colony formation assays as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092864#s2" target="_blank">Materials and Method</a>s. (B) The above assays were quantified. Data represent three independent experiments. “**” indicates a highly significant (<i>P</i>&lt;0.001) difference from controls.</p

Additional file 1: of Combined utility of white blood cell count and blood glucose for predicting in-hospital outcomes in acute ischemic stroke

Investigation group. (DOC 31 kb

Meloxicam inhibits phosphorylation of AKT in a COX-2-depdendent way.

<p>(A) HepG2 cells were incubated with meloxicam (80 μM), and harvested at the indicated time points. (B, C) HepG2 cells were incubated for 72 h with meloxicam (80 μM) in the presence and absence of PGE2 (3 μM) (B) or rh-MMP-2 (25 ng/mL) (C). The above harvested cells were subjected to Western blot analysis. The band density in each assay was measured and normalized to that of GAPDH, respectively. Data represent three independent experiments. “**”, indicates a highly significant (<i>P</i>&lt;0.001) difference.</p

Meloxicam induces cell apoptosis via COX-2-dependent and -independent mechanisms.

<p>(A, B) HepG2 cells were incubated for 72 h with meloxicam (80 μM) in the presence or absence of PGE2 (3 μM) or rh-MMP-2 (25 ng/mL). Untreated cells served as controls. (A) Representative dot plots were taken from cytometrically analyzed cells. (B) The apoptosis rate was calculated. (C) HepG2 cells were incubated with meloxicam (80 μM), and harvested at the indicated time points. (D) HepG2 cells were incubated for 72 h with meloxicam (80 μM) in the presence or absence of PGE2 (3 μM) or MK-2206 (5 μM). (E) HepG2 cells were incubated with meloxicam (80 μM), and harvested at the indicated time points. (F) HepG2 cells were incubated with meloxicam (80 μM) in the presence or absence of PGE2 (3 μM) for 72 h, and harvested. The above harvested cells were subjected to Western blot analysis. The band density in each assay was measured and normalized to that of GAPDH, respectively. Data represent three independent experiments. “*” indicates a significant (<i>P</i>&lt;0.05) difference, and “**”, a highly significant (<i>P</i>&lt;0.001) difference.</p

Meloxicam upregulates E-cadherin and downregulates MMP-2 in a COX-2-dependent way.

<p>HepG2 cells were cultured for 72(80 μM), PGE2 (3 μM) or rh-MMP-2 (25 ng/mL), or the combination. Cell lysates were analyzed by Western blot analysis to detect expression of E-cadherin (A, B) and MMP-1/MMP-2 (C) proteins. The band density in each assay was measured and normalized to that of GAPDH, respectively. (D, E) The concentrations of soluble E-cadherin (sE-cad) in supernatants from the above cell culture were measured by ELISA. (F–H) The above cells were lysed and subjected to quantitative real-time RT-PCR for measuring the levels of E-Cadherin (F) and MMP-2 (G) mRNAs, and to a standard RT-PCR assay, in which PCR products of E-Cadherin (I) and MMP-2 (H) were electrophoresed. GAPDH served as an internal control. Data represent three independent experiments. “*” indicates a significant (<i>P</i>&lt;0.05) difference, and “**”, a highly significant (<i>P</i>&lt;0.001) difference.</p