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•The GdNbO4:Bi3+,Eu3+ phosphors exhibited the characteristics emissions of Bi3+ and Eu3+ under UV light excitation.•The energy transfer from Bi3+ to Eu3+ ions was efficient and they ...displayed tunable multi-color emission.•The obtained phosphors exhibited good thermal stability with activation energy of 0.29 eV and splendid humidity stability.•The maximum absolution and relative sensor sensitivities were 0.0367 K−1 and 3.81% K−1, respectively.•The resultant phosphors exhibited excellent cathode luminescence properties.
Using solid-state reaction technique, we prepared a series of Bi3+/Eu3+-activated GdNbO4 phosphors. Under 308 nm excitation, the energy transfer from Bi3+ to Eu3+ ions, which belonged to the dipole-quadrupole interaction mechanism, allowed the GdNbO4:Bi3+,Eu3+ compounds to display tunable multi-color emissions. The temperature dependent photoluminescence emission and water resistance behaviors of the obtained samples were investigated in detail. Taking full advantage of the diverse thermal quenching performance between Bi3+ and Eu3+ ions along with their distinct characteristic color emission, we designed a highly sensitive non-invasion optical thermometer. The maximum absolute and relative sensor sensitivities of the final compounds were about 0.0367 K−1 and 3.81% K−1, respectively. Moreover, the as-prepared phosphors exhibited excellent cathode-luminescence properties. These above characteristics indicated that Bi3+/Eu3+-activated GdNbO4 phosphors can be used as potential luminescent materials for non-contact temperature measurement and field emission display.
The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted ...by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone-methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process.
The orange–red emitting Ba2CaWO6:xSm3+ (0.01≤x≤0.25) phosphors were synthesized via solid state reaction process. The crystal structure of the phosphor was characterized by XRD. The photoluminescence ...excitation and emission spectra, concentration effect were investigated. The results show an efficient energy transfer from WO66− group to Sm3+ occurs. The emission spectra of the Ba2CaWO6:Sm3+ phosphors consisted of some sharp emission peaks of Sm3+ ions centre at 579nm, 618nm, 625nm, and 675nm. The strongest one is located at 610nm due to 4G5/2→6H7/2 transition of Sm3+, generating bright orange–red light. The optimum dopant concentration of Sm3+ ions in Ba2CaWO6:xSm3+ is around 5mol% and the critical transfer distance of Sm3+ is calculated as 18Å. The fluorescence lifetime of Sm3+ in Ba2CaWO6:0.05Sm3+ is 2.36ms. The Ba2CaWO6:Sm3+ phosphors may be potentially used as orange–red phosphors for white light-emitting diodes.
•A new host-sensitized Sm3+-doped Ba2CaWO6 phosphor was firstly synthesized.•Its structure, luminescent properties are well studied and characterized.•There exists an efficient energy transfer from WO66− group to Sm3+.•The thermal quenching properties of Ba2CaWO6:Sm3+ was firstly evaluated.
Hexanoic acid production by a bacterium using sucrose as an economic carbon source was studied under conditions in which hexanoic acid was continuously extracted by liquid–liquid extraction. ...Megasphaera elsdenii NCIMB 702410, selected from five M. elsdenii strains, produced 4.69 g l⁻¹ hexanoic acid in a basal medium containing sucrose. Production increased to 8.19 g l⁻¹ when the medium was supplemented by 5 g l⁻¹ sodium butyrate. A biphasic liquid–liquid extraction system with 10 % (v/v) alamine 336 in oleyl alcohol as a solvent was evaluated in a continuous stirred-tank reactor held at pH 6. Over 90 % (w/w) of the hexanoic acid in a 0.5 M aqueous solution was transferred to the extraction solvent within 10 h. Cell growth was not significantly inhibited by direct contact of the fermentation broth with the extraction solvent. The system produced 28.42 g l⁻¹ of hexanoic acid from 54.85 g l⁻¹ of sucrose during 144 h of culture, and 26.52 and 1.90 g l⁻¹ of hexanoic acid was accumulated in the extraction solvent and the aqueous fermentation broth, respectively. The productivity and yield of hexanoic acid were 0.20 g l⁻¹ h⁻¹ and 0.50 g g⁻¹ sucrose, respectively.
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•Box–Behnken design was used to understand the effect of process variables.•SFO as co-solvent with SC-CO2 increases the recovery of carotenoid and fucoxanthin.•Water as co-solvent ...with SC-CO2 increases the recovery of phlorotannin.•Fatty acid, antioxidant and oil stability was increased with SFO as co-solvent.•Kinetic models for all the extraction yield were established.
Sunflower oil (SFO), soybean oil, canola oil, ethanol, and water were utilized as co-solvents to support supercritical carbon dioxide (SC-CO2) extraction of total carotenoid (TC), fucoxanthin (FX), and phlorotannin (PT) from brown seaweed (Saccharina japonica). A steepest ascent method with various temperatures 45–55°C, pressures 200–300bar, and co-solvent flow rates 0.50–2.00 (% of CO2, w/w) was used to define the best operative co-solvents to enhance the extraction yields followed by response surface methodology (RSM) to optimize the extraction conditions. The best conditions for the yield of TC and FX were 50.62°C, 300bar, and 2.00% of SFO, while for PT it was 48.98°C, 300bar, and 2.00% of water, respectively. Overall extraction curves were determined for the optimized conditions, and experimental data were used to estimate the kinetic parameters. SFO as co-solvent showed higher fatty acid content, antioxidant activity, and oil stability than the control (SC-CO2 only).
Botrytis cinerea (B. cinerea) is a necrotrophic pathogen that causes significant growth and postharvest commercial losses in cut roses. Postharvest disease severity is affected by ethylene levels ...during transport and storage conditions. In this study, we identified the relationship between ethylene, fungal growth, and ethylene inhibitors during B. cinerea infection in cut ‘Pink Beauty’ roses. The results suggest that cut rose susceptibility to gray mold disease is associated with the developmental stage of flowers, especially the level of senescence, which is stimulated by ethylene biosynthesis in petals. The mRNA levels of ethylene biosynthesis genes in petals were related to the severity of gray mold; however, their expression levels decreased when the cut roses were completely macerated by B. cinerea. B. cinerea infections in cut flowers activated ethylene biosynthesis and signaling pathways, leading to the activation of RhERFs in the petals. Ethylene regulated the development of B. cinerea infections in the cut flowers directly by binding to the receptors or indirectly by promoting the ethylene response in the host tissues. The suppression of ethylene responses in petals and inhibition of the fungal histidine kinase receptor of B. cinerea by 1-methylcylopropene (1-MCP) made cut rose flowers resistant to such necrotrophic pathogens. We also established a working model for ethylene binding and plant and fungus actions in the rose-B. cinerea pathosystem. Understanding the relationship between ethylene and gray mold disease in cut roses and the interaction between ethylene inhibitors and B. cinerea will help improve postharvest treatments for reducing B. cinerea damage in cut flowers.
•Ethylene binding to the receptor (BcHHK5) increases fungal virulence.•1-MCP suppresses the ethylene binding and the ethylene responses in roses.•BcPLS1 and BcSPL1 are induced by ethylene.•B. cinerea infection activates ethylene biosynthesis.
Abstract Toxicity of nanoparticles depends on many factors including size, shape, chemical composition, surface area, surface charge, and others. In this study, we compared the toxicity of different ...sized-silver nanoparticles (AgNPs) which are being widely used in consumer products due to its unique antimicrobial activity. When mice were treated with AgNPs 1 mg/kg for 14 days by oral administration, small-sized AgNPs (22 nm, 42 nm, and 71 nm) were distributed to the organs including brain, lung, liver, kidney, and testis while large-sized AgNPs (323 nm) were not detected in those tissues. The levels of TGF-β in serum were also significantly increased in the treated group of small-sized AgNPs but not in large-sized AgNPs. In addition, B cell distribution was increased in small-sized AgNPs but not in large-sized-AgNPs by the phenotype analysis. However, body weight or in the ratio of organ/body weight were not different between the control group and all the AgNPs-treated groups. The repeated-dose toxicity of AgNPs (42 nm) was also investigated in mice by oral administration for 28 days. By the administration of AgNPs (0.25 mg/kg, 0.50 mg/kg, 1.00 mg/kg), adverse impacts on liver and kidney were observed in a high dose-treated group (1.00 mg/kg), when determined by blood chemistry and histipathological analysis. Cytokines including IL-1, IL-6, IL-4, IL-10, IL-12, and TGF-β were also increased in a dose-dependent manner by repeated oral administration. In addition, B cell distribution in lymphocyte and IgE production were increased. Based on these results, it is suggested that repeated oral administration of nano-sized AgNPs may cause organ toxicity and inflammatory responses in mice.
The Y2O3:R(R = Yb3+, Er3+, Tm3+) nanophosphors were synthesized by a solvothermal method and the temperature dependence of the white upconversion emission was studied using a 975 nm LD. The ...upconversion emission spectra in 1 mol% Er3+/5 mol% Yb3+/xTm3+ tri-doped Y2O3 nanophosphors were sintered at 1000 °C with x from 0 to 0.5 mol%. The blue emission intensity increases increasing Tm3+ concentration from 0 to 0.5 mol%, because the Tm3+ state can be easily reached due to the 2F7/2 → 2F5/2 transition of Yb3+ near 10,000 cm−1. The Y2O3: Er3+/Yb3+/Tm3+ nanophosphors exhibit upconversion emission from white to green with increasing sintering temperature. The calculated CIE coordinates are located in the white region at a pump power of 700 mW at 1000 °C, and the color coordinates were very similar to the standard white light emission. Their upconversion process was described through energy level diagrams and results of upconversion emission spectra and pump power dependence.
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•Er3+/Yb3+/Tm3+ tri-doped Y2O3 nanophosphors were prepared.•Their UC emission spectra include the white light area.•These novel materials can be used in display devices and biomedical applications.
Purpose The purpose of this study was to evaluate the relationship between daily activities and manual dexterity in persons with Parkinson disease. Subjects and Methods The study participants were 25 ...patients with idiopathic Parkinson disease. This study used two clinical tools, the box-and-block test and Schwab and England Activities of Daily Living scale, to investigate the relationship between manual dexterity and Schwab and England Activities of Daily Living score. Results A positive correlation was observed between the Schwab and England Activities of Daily Living and the box-and-block test scores on the more and less affected sides. Moreover, the Schwab and England Activities of Daily Living score had a greater correlation with the box-and-block test score on the less affected side than that on the more affected side. Conclusion Manual dexterity and activities of daily living showed a positive correlation in individuals with Parkinson disease. The results of this study suggest that manual dexterity is an important factor for predicting physical performance in daily living in persons with Parkinson disease.
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