Shoemakerholt8954

Nowadays, rationally preparing heterostructure materials can not only make up for the shortage of individual components, but also exert unexpected performance through synergistic interactions between the components. Herein, a core-shell of WS2@NiCo2O4 screw-like heterostructure arrays grown on carbon cloth (CC) was prepared by a two-step solvothermal method for supercapacitors. As a binder-free flexible electrode, a high areal capacitance of 2449.9 mF cm-2 can be achieved for WS2@NiCo2O4/CC at a current density of 1 mA cm-2. Benefiting from the core-shell of the WS2@NiCo2O4 heterostructure, the capacitive property of the flexible WS2@NiCo2O4/CC electrode is better than those of WS2/CC and NiCo2O4/CC electrodes. Based on WS2@NiCo2O4/CC electrodes, the assembled flexible solid-state symmetric supercapacitor (FSS) device shows a high energy density of ∼45.67 W h kg-1 at a power density of 992.83 W kg-1. Meantime, the WS2@NiCo2O4/CC-assembled FSS device also exhibits high cycling stability with an excellent capacity retention of ∼85.59% after 5000 cycles. Copyright © 2020 American Chemical Society.Many researchers reported that a sigmoid kinetic curve was obtained in oil transesterification with methanol catalyzed by CaO and gave different explanations for this formation. In this paper, heterogeneously catalyzed transesterification of soybean oil with methanol using CaO has been investigated. The solid catalyst and the liquid reaction mixture under different reaction time periods were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and high-performance liquid chromatography (HPLC) to reveal the formation of an S-shape kinetic curve. The appearance of calcium hydroxide, calcium methoxide, calcium glyceroxide, fatty acid calcium, diglycerides, and monoglycerides and their contributions to the kinetic curve have been discussed. The low reaction rate in the induction period can be attributed to mass transfer in this three-phase system. However, the formation of surfactants, diglycerides and monoglycerides, promotes the emulsification of the reaction mixture and numerous emulsion reactors are generated. These emulsion reactors can improve the contact of the solid catalyst with the reactants and thus accelerate the reaction. Copyright © 2020 American Chemical Society.A cyclometallated phosphorescent iridium-based probe to detect CN- was prepared through a cyanide alcoholize reaction based on the C^N type main ligand and N^N type ancillary ligand (2-phenyl pyridine and 1,10-phenanthroline-5-carboxaldehyde, respectively). find more The efficient probe exhibited good sensitivity in response to CN- in an CH3CN and H2O (95/5) mixture within a 1.23 μM detection limit. The response of PL is directly in line with the concentration of CN- from 0 to 2.0 equiv. The PL investigation of other reactive anions proved the great selectivity to CN-. Additionally, upon adding 1.0 equiv. of cyanide, the formation of cyanohydrin was correctly elucidated in 1H NMR, FT-IR, and mass spectra studies. The conspicuous results indicate that the iridium complex has the potential possibility of application in other biosystems related to CN-. Copyright © 2020 American Chemical Society.Red pigmented marine bacteria, Pseudoalteromonas rubra strains PS1 and SB14, were isolated from two sampling locations in different ecosystems on Alor Island, Indonesia, and cultured in the laboratory. We analyzed the 16S rRNA gene sequences and examined the pigment composition and found that both strains produced cycloprodigiosin (3), prodigiosin (4), and 2-methyl-3-hexyl-prodiginine (5) as major compounds. In addition, we detected three minor compounds prodigiosin derivatives 2-methyl-3-propyl prodiginine (1), 2-methyl-3-butyl prodiginine (2), and 2-methyl-3-heptyl-prodiginine (6). To our knowledge, this is the first report that P. rubra synthesizes not only prodigiosin and cycloprodigiosin but also four prodigiosin derivatives that differ in the length of the alkyl chain. The antimicrobial activity of cycloprodigiosin, prodigiosin, and 2-methyl-3-hexyl-prodiginine was examined by a disk-diffusion test against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Candida albicans. We found that, at a concentration of 20 μg/mL, cycloprodigiosin showed the greatest inhibition (25.1 ± 0.55 mm) against S. aureus. Copyright © 2020 American Chemical Society.High-pressure phase transitions of AlB2-type transition-metal diborides (TMB2; TM = Zr, Sc, Ti, Nb, and Y) were systematically investigated using first-principles calculations. Upon subjecting to pressure, these TMB2 compounds underwent universal phase transitions from an AlB2-type to a new high-pressure phase tP6 structure. The analysis of the atomistic mechanism suggests that the tP6 phases result from atomic layer folds of the AlB2-type parent phases under pressure. Stability studies indicate that the tP6-structured ZrB2, ScB2, and NbB2 are stable and may be observed under high pressure and the tP6-structured TiB2 phase may be recovered at ambient pressure. Copyright © 2020 American Chemical Society.Accurate prediction of the absolute or relative protein-ligand binding affinity is one of the major tasks in computer-aided drug design projects, especially in the stage of lead optimization. In principle, the alchemical free energy (AFE) methods such as thermodynamic integration (TI) or free-energy perturbation (FEP) can fulfill this task, but in practice, a lot of hurdles prevent them from being routinely applied in daily drug design projects, such as the demanding computing resources, slow computing processes, unavailable or inaccurate force field parameters, and difficult and unfriendly setting up and post-analysis procedures. In this study, we have exploited practical protocols of applying the CPU (central processing unit)-TI and newly developed GPU (graphic processing unit)-TI modules and other tools in the AMBER software package, combined with ff14SB/GAFF1.8 force fields, to conduct efficient and accurate AFE calculations on protein-ligand binding free energies. We have tested 134 protein-ligand complexes in total for four target proteins (BACE, CDK2, MCL1, and PTP1B) and obtained overall comparable performance with the commercial Schrodinger FEP+ program (WangJ.