Effect of Functionalized Benzene Derivatives as Potential Hole Scavengers for BiVO4 and rGO-BiVO4 Photoelectrocatalytic Hydrogen Evolution.

Sustainable hydrogen production is one of the main challenges today in the transition to a green and sustainable economy. Photocatalytic hydrogen production is one of the most promising technologies, amongst which BiVO4-based processes are highly attractive due to their suitable band gap for solar-driven processes. However, the performance of BiVO4 alone in this role is often unsatisfactory. Herein we report the improvement of BiVO4 performance with reduced graphene oxide (rGO) as a co-catalyst for the photoelectrochemical water splitting (PEC-WS) in the presence of simple functionalized benzene derivatives (SFBDs), i.e., phenol (PH), benzoic acid (BA), salicylic acid (SA), and 5-aminosalicylic acid (5-ASA) as potential photogenerated hole scavengers from contaminated wastewaters. Linear sweep voltammetry and chronoamperometry, along with electrochemical impedance spectroscopy were utilized to elucidate PEC-WS performance under illumination. rGO has remarkably improved the performance of BiVO4 in this role by decreasing photogenerated charge recombination. In addition, 5-ASA greatly improved current densities. After 120 min under LED illumination, 0.53 µmol of H2 was produced. The type and concentration of SFBDs can have significant and at times opposite effects on the PEC-WS performance of both BiVO4 and rGO-BiVO4.

Antiproliferative activity of morpholine-based compounds on MCF-7 breast cancer, colon carcinoma C26, and normal fibroblast NIH-3T3 cell lines and study of their binding affinity to calf thymus-DNA and bovine serum albumin.

This report describes the results of a study on the antiproliferative activity of the morpholine-based ligand 1,3-bis(1-morpholinothiocarbonyl)benzene (HL) and its nickel(II) complex (NiL) against human breast cancer cells (MCF-7), colon carcinoma cells (C26), and normal fibroblast NIH-3T3 cells. NiL showed better cytotoxicity on both cancerous cells relative to normal cells in vitro with the highest selective index of 2.22 in MCF-7 cells. The interaction of both compounds with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) was studied using various spectroscopic techniques and analytical methods such as UV - vis titrations, thermal denaturation, circular dichroism, competitive fluorescent intercalator displacement assays, as well as molecular modeling. The fluorescence intensity of the probe molecule increases clearly when HL and NiL are added to the methylene blue (MB)-DNA system. Furthermore, the binding of HL and NiL quenches the BSA fluorescence, revealing a 1:1 interaction with a binding constant of about 105 M-1. Communicated by Ramaswamy H. Sarma.

Enhanced photoelectrochemical water splitting of CrTiO2 nanotube photoanodes by the decoration of their surface via the photodeposition of Ag and Au.

It is of great significance to develop green fuels in order to prevent the accumulation of carbon dioxide generated by the combustion of conventional fossil fuels. A potential, clean, renewable alternative fuel, which may be produced from solar energy, stored and safely transported, is hydrogen. In this work, bare CrTiO2 NTs were fabricated using an in situ anodizing process. CrTiO2 NTs were then modified with the photodeposition of noble metals (Ag and Au) at different light irradiation times (10-120 min). The new photocatalysts have been characterized using SEM, EDX, XRD, Raman and UV-vis spectra. The impact of noble metals on the photo-electrochemical activities of the photocatalysts has been evaluated. In addition, electrochemical impedance spectroscopy was conducted for the semiconductor/electrolyte interface. Most of the current density is related to Ag4/CrTiO2 NTs and Au4/CrTiO2 NTs, and is nearly 2 and 3 times as that of the bare CrTiO2 NTs, respectively. All of the samples have adequate stability during continuous illumination for 1200 s. Finally, water splitting was performed under light irradiation at 0.6 V vs. Ag/AgCl for 60 min. Ag4/CrTiO2 NTs and Au4/CrTiO2 NTs have the highest H2 evolution among their families, corresponding to 0.52 and 0.80 ml cm-2 h-1, respectively.

A computational study to identify the key residues of peroxisome proliferator-activated receptor gamma in the interactions with its antagonists.

Peroxisome proliferator-activated receptors (PPARs) compose a family of nuclear receptors, PPARα, PPARß, and PPARγ, which mediate the effects of lipidic ligands at the transcriptional level. Among these, the PPARγ has been known to regulate adipocyte differentiation, fatty acid storage and glucose metabolism, and is a target of antidiabetic drugs. In this work, the interactions between PPARγ and its six known antagonists were investigated using computational methods such as molecular docking, molecular dynamics (MD) simulations, and the hybrid quantum mechanics/molecular mechanics (QM/MM). The binding energies evaluated by molecular docking varied between -22.59 and -35.15 kJ mol- 1. In addition, MD simulations were performed to investigate the binding modes and PPARγ conformational changes upon binding of antagonists. Analysis of the root-mean-square fluctuations (RMSF) of backbone atoms shows that H3 of PPARγ has a higher mobility in the absence of antagonists and moderate conformational changes were observed. The interaction energies between antagonists and each PPARγ residue involved in the interactions were studied by QM/MM calculations. These calculations reveal that antagonists with different structures show different interaction energies with the same residue of PPARγ. Therefore, it can be concluded that the key residues vary depending on the structure of the ligand, which binds to PPARγ.