303 research outputs found

    Phytochemical-based nano emulsions for stored grain protection: Presentation

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    Stored grain losses caused by pest insects contribute significantly to the global food crisis. Currently, there are two main chemical control methods against stored product insect pests: fumigation with very toxic gases and grain protection by residual contact insecticides. Today, the global tendency is to prevent/reduce the wide use of insecticides, which have high toxicity to humans and harm the environment. Therefore, there is an urgent need to develop alternative eco-friendly approaches for stored insect pest control. Essential oils from Micromeria fruticosa and Mentha rotundifolia (Fam. Labiatae) and their main constituent pulegone which previously were shown by us as very active against stored product insect pests, were encapsulated into coarse and nano emulsions. The insecticidal activity of the developed formulations against primary internal insect rice weevil (Sitophilus oryzae L.) and secondary external pest red flour beetle (Tribolium castaneum Herbst) was evaluated in laboratory and pilot experiments. It was found that the phytochemical-based nano emulsions offered significant advantages and provided powerful and prolonged biological activity compare with the coarse formulations. The developed nano emulsions could serve as a natural, effective, low-toxify for human, and environmentally preferred method for protection stored grain and dry food products from pest insects.Stored grain losses caused by pest insects contribute significantly to the global food crisis. Currently, there are two main chemical control methods against stored product insect pests: fumigation with very toxic gases and grain protection by residual contact insecticides. Today, the global tendency is to prevent/reduce the wide use of insecticides, which have high toxicity to humans and harm the environment. Therefore, there is an urgent need to develop alternative eco-friendly approaches for stored insect pest control. Essential oils from Micromeria fruticosa and Mentha rotundifolia (Fam. Labiatae) and their main constituent pulegone which previously were shown by us as very active against stored product insect pests, were encapsulated into coarse and nano emulsions. The insecticidal activity of the developed formulations against primary internal insect rice weevil (Sitophilus oryzae L.) and secondary external pest red flour beetle (Tribolium castaneum Herbst) was evaluated in laboratory and pilot experiments. It was found that the phytochemical-based nano emulsions offered significant advantages and provided powerful and prolonged biological activity compare with the coarse formulations. The developed nano emulsions could serve as a natural, effective, low-toxify for human, and environmentally preferred method for protection stored grain and dry food products from pest insects

    Chlorido{[2-(dicyclo­hexyl­phosphano­yl)eth­yl]bis­[2-(dicyclo­hexyl­phosphan­yl)eth­yl]phosphane}platinum(II) chloride dichloro­methane hemisolvate tetra­hydrate

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    The title compound, [PtCl(C42H78OP4)]Cl·0.5CH2Cl2·4H2O, crystallizes as a contact ion-pair with two close inter­molecular C—H⋯Cl− contacts between CH acidic αH atoms of the phosphane ligand and the chloride anion. A chloride ligand together with three coordinating P ligand atoms create a slightly distorted square-planar coordination environment around the PtII center. An inter­molecular water O—H⋯Cl− and water O—H⋯OP hydrogen-bond network completes the coordination around the anion. In addition, a disordered CH2Cl2 solvent mol­ecule cocrystallized within a hydro­phobic cavity spanned by the dicyclo­hexyl­phosphane ligands

    Enhancing electron affinity and tuning band gap in donor–acceptor organic semiconductors by benzothiadiazole directed C–H borylation

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    Electrophilic borylation using BCl3 and benzothiadiazole to direct the C–H functionalisation of an adjacent aromatic unit produces fused boracyclic materials with minimally changed HOMO energy levels but significantly reduced LUMO energy levels. In situ alkylation and arylation at boron using Al(alkyl)3 or Zn(aryl)2 is facile and affords boracycles that possess excellent stability towards protic solvents, including water, and display large bathochromic shifts leading to far red/NIR emission in the solid state with quantum yields of up to 34%. Solution fabricated OLEDs with far red/NIR electroluminescence are reported with EQEs > 0.4%

    An element through the looking glass: Exploring the Au-C, Au-H and Au-O energy landscape

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    Gold, the archetypal “noble metal”, used to be considered of little interest in catalysis. It is now clear that this was a misconception, and a multitude of gold-catalysed transformations has been reported. However, one consequence of the long-held view of gold as inert metal is that its organometallic chemistry contains many “unknowns”, and catalytic cycles devised to explain gold's reactivity draw largely on analogies with other transition metals. How realistic are such mechanistic assumptions? In the last few years a number of key compound classes have been discovered that can provide some answers. This Perspective attempts to summarise these developments, with particular emphasis on recently discovered gold(III) complexes with bonds to hydrogen, oxygen, alkenes and CO ligands

    Efficacy of limonene nano coatings on post-harvest shelf life of strawberries

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    Strawberries are highly demanded fruits because of their color, nutritional values and appearance. The aim of this study was to develop and characterize alginate and limonene liposomes as edible coating materials and to determine their efficacy in shelf life extension and maintaining quality parameters of ‘Chandler’ strawberries. Alginate solution (1.5% w/v) and Limonene liposomes prepared from 80% lecithin and 20% PDA were used as edible coating materials. Fungal decay percentage, total yeast and mold counts, headspace atmosphere analysis, total soluble solids, pH, titratable acidity, total anthocyanin content and total phenolics were analyzed to assess fruit quality during 14 days at 4 °C of storage. Days of storage was found to be significant in maintaining the quality of the strawberries. Among the coating types, limonene liposomes were found to be significantly more effective in maintaining the lower concentration of carbon dioxide (CO2), lower the change in pH (3.9), and had higher total anthocyanin (43.85) content during storage than those without a liposomal coating. Thus, limonene liposomes were found to be useful for extending the shelf life and maintaining quality of strawberry fruits

    Aqueous electrosynthesis of an electrochromic material based water-soluble EDOT-MeNH2 hydrochloride

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    2\u27-Aminomethyl-3,4-ethylenedioxythiophene (EDOT-MeNH2) showed unsatisfactory results when its polymerization occurred in organic solvent in our previous report. Therefore, a water-soluble EDOT derivative was designed by using hydrochloric modified EDOT-MeNH2 (EDOT-MeNH2·HCl) and electropolymerized in aqueous solution to form the corresponding polymer with excellent electrochromic properties. Moreover, the polymer was systematically explored, including electrochemical, optical properties and structure characterization. Cyclic voltammetry showed low oxidation potential of EDOT-MeNH2·HCl (0.85 V) in aqueous solution, leading to the facile electrodeposition of uniform the polymer film with outstanding electroactivity. Compared with poly(2′-aminomethyl- 3,4-ethylenedioxythiophene) (PEDOT-MeNH2), poly(2′-aminomethyl-3,4-ethylenedioxythiophene salt) (PEDOT-MeNH3 +A-) revealed higher efficiencies (156 cm2 C-1), lower bandgap (1.68 eV), and faster response time (1.4 s). Satisfactory results implied that salinization can not only change the polymerization system, but also adjust the optical absorption, thereby increase the electrochromic properties
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