- Potassium Bromide Surface Passivation on CsPbI3-xBrx Nanocrystals for Efficient and Stable Pure Red Perovskite Light-Emitting Diodes
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All-inorganic lead halide perovskite nanocrystals (NCs) are potential candidates for fabricating high-performance light-emitting diodes (LEDs) owing to their precisely tunable bandgaps, high photoluminescence (PL) efficiency, and excellent color purities. However, the performance of pure red (630-640 nm) all-inorganic perovskite LEDs is still limited by the halide segregation-induced instability of the electroluminescence (EL) of mixed halide CsPbI3-xBrx NCs. Herein, we report an effective approach to improving the EL stability of pure red all-inorganic CsPbI3-xBrx NC-based LEDs via the passivation of potassium bromide on NCs. By adding potassium oleate to the reaction system, we obtained potassium bromide surface-passivated (KBr-passivated) CsPbI3-xBrx NCs with pure red PL emission and a photoluminescence quantum yield (PLQY) exceeding 90%. We determine that most potassium ions present on the surface of NCs bind with bromide ions and thus demonstrate that potassium bromide surface passivation of NCs can both improve the PL stability and inhibit the halide segregation of NCs. Using KBr-passivated CsPbI3-xBrx NCs as an emitting layer, we fabricated stable and pure red perovskite LEDs with emission at 637 nm, showing a maximum brightness of 2671 cd m-2, maximum external quantum efficiency of 3.55%, and good EL stability. The proposed KBr-passivated NC strategy will open a new avenue for fabricating efficient, stable, and tunable pure color perovskite NC LEDs.
- Yang, Jun-Nan,Song, Yang,Yao, Ji-Song,Wang, Kun-Hua,Wang, Jing-Jing,Zhu, Bai-Sheng,Yao, Ming-Ming,Rahman, Sami Ur,Lan, Yi-Feng,Fan, Feng-Jia,Yao, Hong-Bin
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- Interaction kinetics of liposome-incorporated unsaturated fatty acids with fatty acid-binding protein 3 by surface plasmon resonance
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The role of heart-type fatty acid-binding protein (FABP3) in human physiology as an intracellular carrier of fatty acids (FAs) has been well-documented. In this study, we aimed to develop an analytical method to study real-time interaction kinetics between FABP3 immobilized on the sensor surface and unsaturated C18 FAs using surface plasmon resonance (SPR). To establish the conditions for SPR experiments, we used an FABP3-selective inhibitor 4-(2-(1-(4-bromophenyl)-5-phenyl-1H-pyrazol-3-yl)-phenoxy)-butyric acid. The affinity index thus obtained was comparable to that reported previously, further supporting the usefulness of the SPR-based approach for evaluating interactions between FABPs and hydrophobic ligands. A pseudo-first-order affinity of FABP3 to K+ petroselinate (C18:1 Δ6 cis), K+ elaidate (C18:1 Δ9 trans), and K+ oleate (C18:1 Δ9 cis) was characterized by the dissociation constant (Kd) near micromolar ranges, whereas K+ linoleate (C18:2 Δ9,12 cis/cis) and K+ α-linolenate (C18:3 Δ9,12,15 cis/cis/cis) showed a higher affinity to FABP3 with Kd around 1 × 10-6 M. Interactions between FAPB3 and C18 FAs incorporated in large unilamellar vesicles consisting of 1,2-dimyristoyl-sn-glycero-3- phosphocholine and FAs (5:1 molar ratio) were also analysed. Control DMPC liposomes without FA showed only marginal binding to FABP3 immobilized on a sensor chip while liposome-incorporated FA revealed significant responses in sensorgrams, demonstrating that the affinity of FAs to FABP3 could be evaluated by using the liposome-incorporated analytes. Significant affinity to FABP3 was observed for monounsaturated fatty acids (Kd in the range of 1 × 10-7 M). These experiments demonstrated that highly hydrophobic compounds in a liposome-incorporated form could be subjected to SPR experiments for kinetic analysis.
- Tan, Maria Carmen,Matsuoka, Shigeru,Ano, Hikaru,Ishida, Hanako,Hirose, Mika,Sato, Fuminori,Sugiyama, Shigeru,Murata, Michio
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- Fatty acid potassium had beneficial bactericidal effects and removed Staphylococcus aureus biofilms while exhibiting reduced cytotoxicity towards mouse fibroblasts and human keratinocytes
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Wounds frequently become infected or contaminated with bacteria. Potassium oleate (C18:1K), a type of fatty acid potassium, caused >4 log colony-forming unit (CFU)/mL reductions in the numbers of Staphylococcus aureus and Escherichia coli within 10 min and a >2 log CFU/mL reduction in the number of Clostridium difficile within 1 min. C18:1K (proportion removed: 90.3%) was significantly more effective at removing Staphylococcus aureus biofilms than the synthetic surfactant detergents sodium lauryl ether sulfate (SLES) (74.8%, p 0.01) and sodium lauryl sulfate (SLS) (78.0%, p 0.05). In the WST (water-soluble tetrazolium) assay, mouse fibroblasts (BALB/3T3 clone A31) in C18:1K (relative viability vs. control: 102.8%) demonstrated a significantly higher viability than those in SLES (30.1%) or SLS (18.1%, p 0.05). In a lactate dehydrogenase (LDH) leakage assay, C18:1K (relative leakage vs. control: 108.9%) was found to be associated with a significantly lower LDH leakage from mouse fibroblasts than SLES or SLS (720.6% and 523.4%, respectively; p 0.05). Potassium oleate demonstrated bactericidal effects against various species including Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Clostridium difficile; removed significantly greater amounts of Staphylococcus aureus biofilm material than SLES and SLS; and maintained fibroblast viability; therefore, it might be useful for wound cleaning and peri-wound skin.
- Kawahara, Takayoshi,Takita, Miki,Masunaga, Akihiro,Morita, Hayato,Tsukatani, Tadayuki,Nakazawa, Kohji,Go, Daisuke,Akita, Sadanori
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- Continuous preparation method of metal fatty acid salt
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The invention relates to a continuous preparation method of metal fatty acid salt. The continuous preparation method of the metal fatty acid salt comprises the step of continuously enabling fatty acidand metal hydroxides to react in a solvent and prepare the metal fatty acid salt in a microchannel reactor or pipeline reactor. The preparation method disclosed by the invention can control the particle diameter of a product material to be within 70nm and 1000nm, and the particle diameter of the product material can be adjusted as needed; the metal fatty acid salt is simple in preparation method,short in technological process, few in three wastes (waste water, waste residues and waste gas), beneficial to environmental protection and suitable for industrial production; the reactor used in theinvention has short reaction time, high safety, high efficiency and large productivity, and can realize continuous production, furthermore, the space utilization rate of workshops is high, and mass production can be realized; by adopting the preparation method disclosed by the invention, the solvent can be recycled to lower the production cost; and the preparation method has high conversion rateof raw materials, stable quality and high purity.
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Paragraph 0092; 0093; 0094; 0095
(2019/04/04)
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- ANTIVIRAL AGENT AND CLEANSING AGENT
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It is an object to provide an antiviral agent that can be used for persons having sensitive skin or on the face, inactivates viruses such as a norovirus and an influenza virus, and is excellent in germicidal properties. Further provided is a cleansing agent that does not lead to environmental pollution since the cleansing agent is easily decomposed in the natural environment, scarcely causes eczema and allergic dermatitis since no germicidal agent is added, and has an antiviral performance. The antiviral agent containing a surface-active agent having a C18 unsaturated alkyl group as an active component. It is not always necessary to lather or rinse off with water like cleansing agents such as medicated soaps since the antiviral agent of the present invention at a very low concentration can inactivate the virus.
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