The dye sensitized solar cells (DSSCs) have been extensively studied due to their low production cost and simple fabrication process. Dye co-sensitization broadens the absorption spectrum of the sensitizer;thus enhanc...The dye sensitized solar cells (DSSCs) have been extensively studied due to their low production cost and simple fabrication process. Dye co-sensitization broadens the absorption spectrum of the sensitizer;thus enhances light harvesting efficiency;and contributes to the improvement of the DSSCs overall efficiency. In this study we performed theoretical design of complex molecule (C45H32N2O4) through combination (esterification reaction) of the natural dye lawsone and synthetic metal free indoline dye D131. The excitation energies, vibration spectra, molecular structures, electronic absorption spectra and electron transitions in individual dyes and complex molecule were investigated using density functional theory (DFT) and time dependent density functional theory (TD-DFT) B3LYP5 methods, with 3-21G, 6-31G and 6-31G(d,p) basis sets. The UV-Vis absorption spectra of the individual dyes and their mixture in chloroform solution were measured using spectrophotometer. For the complex formation reaction, enthalpy, entropy and Gibbs free energy were calculated and the results indicated the reaction was endothermic and non-spontaneous. Electron density distribution of the frontier and adjacent molecular orbitals and energy levels alignment were used for analysis of the electronic spectra and mechanism of transitions. The results indicated that the designed complex molecule satisfied the requirements for good photosensitizer of DSSCs.展开更多
Objective: One appealing strategy to overcome and prevent resistant problem is the use of combined two or more antibacterial substances. Lawsone methyl ether(LME) is the naphthoquinone found in the leaves of Impatiens...Objective: One appealing strategy to overcome and prevent resistant problem is the use of combined two or more antibacterial substances. Lawsone methyl ether(LME) is the naphthoquinone found in the leaves of Impatiens balsamina. The objective of this study is to determine the interaction of LME with some antibiotics(ampicillin, tetracycline, norfloxacin, and clotrimazole) and a natural compound, artocarpin against methicillin-resistant Staphylococcus aureus(MRSA), Candida albicans, and Trychophyton rubrum.Methods: A broth microdilution method was used to determine the minimum inhibition concentration(MIC). Synergistic effects were evaluated at their own MIC using the checkerboard method and time-kill assay.Results: LME showed moderate antibacterial activity against MRSA with MIC value of 15.6 μg/mL, and exhibited strong antifungal activities against T. rubrum and C. albicans with MIC values of 7.8 and 3.9 μg/m L,respectively. The interaction of LME with the natural compound artocarpin against MRSA produced a synergy with fractional inhibitory concentration index(FICI) value of 0.31, while the combination of LME and clotrimazole exhibited synergy against C. albicans and T. rubrum with FICI values of 0.38 and 0.24, respectively. The time-kill assays confirmed that the compounds in combination enhanced their antimicrobial activities against the resistant microorganisms with different degrees.Conclusion: LME in combination with clotrimazole exhibited synergy effect against C. albicans and T.rubrum. In combination with artocarpin, it showed synergy effect against MRSA.展开更多
Biodegradable and absorptive wound dresses with antibacterial activity are in demand to accelerate wound heal-ing along with eliminating bacterial infection.Plant-derived naphthoquinones compounds such as lawsone have...Biodegradable and absorptive wound dresses with antibacterial activity are in demand to accelerate wound heal-ing along with eliminating bacterial infection.Plant-derived naphthoquinones compounds such as lawsone have shown sustained antibacterial functions to avoid development of bacterial resistance by reducing pH or attaching to bacterial proteins.Here the nanofibrous mats based on chitosan/polyethylene oxide(PEO)fibers containing various concentrations of lawsone(0,1,3,7,10%wt.)were fabricated by electrospinning for potential applications as wound dressing materials.The results exhibited that the chitosan/PEO/Lawsone nanofibers possess antibacterial activity toward Gram-negative and-positive bacteria.Surprisingly,the addition of lawsone in the proper amount into chitosan/PEO nanofibers not only introduced an antithetical property but also reduced the platform’s cytotoxicity,promoting cell viability of normal human fibroblast cells.Accordingly,the achieved data suggest the potential application of biocompatible nanofibrous mats as an antibacterial wound dressing material.展开更多
眼镜蛇科Elapidae已知349种（Pyron＆Burbrink,2012）,其中眼镜蛇亚科Elapinae 130多种,分隶18个属（Lawson et al.,2005;赵尔宓,2006）。该亚科蛇类具神经毒,形态各异,身体大小差别很大。某些体形较大的物种或类群,如眼镜王蛇属Ophioph...眼镜蛇科Elapidae已知349种（Pyron＆Burbrink,2012）,其中眼镜蛇亚科Elapinae 130多种,分隶18个属（Lawson et al.,2005;赵尔宓,2006）。该亚科蛇类具神经毒,形态各异,身体大小差别很大。某些体形较大的物种或类群,如眼镜王蛇属Ophiophaqus、眼镜蛇属Naja、曼巴蛇属Dendroaspis等,具有较高的经济和观赏价值,因而受到较多的关注和研究。然而,该亚科中体型较小的种类,如中华珊瑚蛇属Sinomicrurus物种,由于它们攻击性弱、生活隐匿、野生数量较少、标本不易获得等原因,却较少受到关注和研究。展开更多
文摘The dye sensitized solar cells (DSSCs) have been extensively studied due to their low production cost and simple fabrication process. Dye co-sensitization broadens the absorption spectrum of the sensitizer;thus enhances light harvesting efficiency;and contributes to the improvement of the DSSCs overall efficiency. In this study we performed theoretical design of complex molecule (C45H32N2O4) through combination (esterification reaction) of the natural dye lawsone and synthetic metal free indoline dye D131. The excitation energies, vibration spectra, molecular structures, electronic absorption spectra and electron transitions in individual dyes and complex molecule were investigated using density functional theory (DFT) and time dependent density functional theory (TD-DFT) B3LYP5 methods, with 3-21G, 6-31G and 6-31G(d,p) basis sets. The UV-Vis absorption spectra of the individual dyes and their mixture in chloroform solution were measured using spectrophotometer. For the complex formation reaction, enthalpy, entropy and Gibbs free energy were calculated and the results indicated the reaction was endothermic and non-spontaneous. Electron density distribution of the frontier and adjacent molecular orbitals and energy levels alignment were used for analysis of the electronic spectra and mechanism of transitions. The results indicated that the designed complex molecule satisfied the requirements for good photosensitizer of DSSCs.
基金supported by The Thailand Research Fund (Grant No. DBG6180031)
文摘Objective: One appealing strategy to overcome and prevent resistant problem is the use of combined two or more antibacterial substances. Lawsone methyl ether(LME) is the naphthoquinone found in the leaves of Impatiens balsamina. The objective of this study is to determine the interaction of LME with some antibiotics(ampicillin, tetracycline, norfloxacin, and clotrimazole) and a natural compound, artocarpin against methicillin-resistant Staphylococcus aureus(MRSA), Candida albicans, and Trychophyton rubrum.Methods: A broth microdilution method was used to determine the minimum inhibition concentration(MIC). Synergistic effects were evaluated at their own MIC using the checkerboard method and time-kill assay.Results: LME showed moderate antibacterial activity against MRSA with MIC value of 15.6 μg/mL, and exhibited strong antifungal activities against T. rubrum and C. albicans with MIC values of 7.8 and 3.9 μg/m L,respectively. The interaction of LME with the natural compound artocarpin against MRSA produced a synergy with fractional inhibitory concentration index(FICI) value of 0.31, while the combination of LME and clotrimazole exhibited synergy against C. albicans and T. rubrum with FICI values of 0.38 and 0.24, respectively. The time-kill assays confirmed that the compounds in combination enhanced their antimicrobial activities against the resistant microorganisms with different degrees.Conclusion: LME in combination with clotrimazole exhibited synergy effect against C. albicans and T.rubrum. In combination with artocarpin, it showed synergy effect against MRSA.
基金supported by the Research and Technology Deputy of the Hamadan University of Medical Sciences(Grant number 9902231097).
文摘Biodegradable and absorptive wound dresses with antibacterial activity are in demand to accelerate wound heal-ing along with eliminating bacterial infection.Plant-derived naphthoquinones compounds such as lawsone have shown sustained antibacterial functions to avoid development of bacterial resistance by reducing pH or attaching to bacterial proteins.Here the nanofibrous mats based on chitosan/polyethylene oxide(PEO)fibers containing various concentrations of lawsone(0,1,3,7,10%wt.)were fabricated by electrospinning for potential applications as wound dressing materials.The results exhibited that the chitosan/PEO/Lawsone nanofibers possess antibacterial activity toward Gram-negative and-positive bacteria.Surprisingly,the addition of lawsone in the proper amount into chitosan/PEO nanofibers not only introduced an antithetical property but also reduced the platform’s cytotoxicity,promoting cell viability of normal human fibroblast cells.Accordingly,the achieved data suggest the potential application of biocompatible nanofibrous mats as an antibacterial wound dressing material.
文摘眼镜蛇科Elapidae已知349种（Pyron＆Burbrink,2012）,其中眼镜蛇亚科Elapinae 130多种,分隶18个属（Lawson et al.,2005;赵尔宓,2006）。该亚科蛇类具神经毒,形态各异,身体大小差别很大。某些体形较大的物种或类群,如眼镜王蛇属Ophiophaqus、眼镜蛇属Naja、曼巴蛇属Dendroaspis等,具有较高的经济和观赏价值,因而受到较多的关注和研究。然而,该亚科中体型较小的种类,如中华珊瑚蛇属Sinomicrurus物种,由于它们攻击性弱、生活隐匿、野生数量较少、标本不易获得等原因,却较少受到关注和研究。
