221 research outputs found

    Triterpenoids and Sterols from the Leaves and Twigs of Melia azedarach

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    Two new triterpenoids (1 and 2) and a new sterol (3), together with six known constituents (4ā€“9), were isolated from the leaves and twigs of Melia azedarach. Their chemical structures were elucidated on the basis of spectroscopic analysis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13659-014-0019-1) contains supplementary material, which is available to authorized users

    Toxicities comparison of rotenone and acetone extract of Tephrosiavogelii andĀ DerrisĀ trifoliate against Solenopsis invicta

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    The high rotenone content and the rotenone crude extract of Tephrosia vogelii and Derris trifoliata were evaluated for its efficacy in the control of red imported fire (RIFA), Solenopsis invicta under both laboratory and field conditions. The acetone extracts of D. trifoliata roots and T. vogelii leaves exhibited strong toxicity to macroergate and micrergate of RIFA. When active ingredients of the crude extracts were convert to rotenone, the activity of the acetone extracts were higher than that of rotenone technical material. At the same time, the extracts showed significant inhibitory effect on walking ability and grasping ability of worker ants and stronger than the effect of 98.6% rotenone technical material. Under field conditions, the 0.01% rotenone-bait, formulated with the acetone extract of D. trifoliata roots and T. vogelii leaves, had the same control effect on RIFA as that of 0.01% fipronil-bait when treated after 30 d. The bait formulated with the extract of D. trifoliata exhibited quicker and higher effect on RIFA than that of rotenone technical material. It was showed that the acetone extracts of D. trifoliata roots and T. vogelii leaves are able to control S. invicta under both laboratory and field conditions and can be used as an effective agent against RIFA

    Poly[[bisĀ­(Ī¼-4,4ā€²-bipyridine-Īŗ2 N:Nā€²)copper(I)] perchlorate 0.24-hydrate]

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    The title copper(I) polymeric compound, {[Cu(C10H8N2)2]ClO4Ā·0.24H2O}n, obtained by the reaction of Cu(ClO4)2 and 4,4ā€²-bipyridine (4,4ā€²-bpy) under hydroĀ­thermal conditions, features a fourfold-interĀ­penetrated diamondoid coordination framework. The asymmetric unit consists of two CuI atoms, three 4,4ā€²-bpy ligands in general positions and two halves of two centrosymmetric 4,4ā€²-bpy ligands, two ClO4 āˆ’ anions and water molĀ­ecule with a site-occupancy factor of 0.480ā€…(17). The CuI atoms are in a distorted tetraĀ­hedral coordination environment and are bridged by 4,4ā€²-bpy ligands, forming a diamondoid cationic polymeric framework that encloses two symmetry-independent channels along [100], which accommodate perchlorate anions and water molĀ­ecules

    An analysis of risk factors of non-fatal drowning among children in rural areas of Guangdong Province, China: a case-control study

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    <p/> <p>Background</p> <p>Drowning is a major cause of morbidity and mortality for children, yet non-fatal drowning remains poorly understood. The aim of this study was to explore potential modifiable risk factors of non-fatal drowning among children in rural areas of China.</p> <p>Methods</p> <p>A cross-sectional survey was first conducted to obtain non-fatal drowning cases, and 7432 students in grades three to eight from 17 schools participated in the cross sectional survey. Of these, 805 students reported that they experienced non-fatal drowning in the previous year. Then 368 cases were selected randomly to participate in a 1:1 matched case-control study. Each drowning case was matched by one control with the same sex and similar age (the gap less than 2 years) who was selected randomly from the same class.</p> <p>Results</p> <p>Boys were more likely to be involved in non-fatal drowning. Non-fatal drowning most often happened in the afternoon (65.1%) and natural bodies of water were the most common sites of drowning (71.1%). Swimming, diving and playing in natural waters were the leading activities that preceded non-fatal drowning. The significant risk factors for non-fatal drowning were swimming in natural waters without adult supervision (OR = 3.40, 95% CI: 1.92-6.03), playing in or beside natural waters (OR = 2.08, 95% CI: 1.17-3.70) and poor swimming skills (OR = 2.74, 95% CI: 1.14-6.62). However, the following variables were protective factors: supervisor aged 30 years or over (OR = 0.20, 95% CI: 0.09-0.49) and no water activities (OR = 0.36, 95% CI: 0.18-0.70).</p> <p>Conclusions</p> <p>The reduction in dangerous water activities, swimming training and enhancement in supervision among children might decrease the risk of non-fatal drowning.</p

    Iridium(III) complex-based activatable probe for phosphorescent/time-gated luminescent sensing and imaging of cysteine in mitochondria of live cells and animals

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    This study reports an activatable iridium(III) complex probe for phosphorescence/time-gated luminescence detection of cysteine (Cys) in vitro and in vivo. The probe, [Ir(ppy)2(NTY-bpy)](PF6), is developed by incorporating a strong electron withdrawing group, nitroolefin, into a bipyridine ligand of the Ir(III) complex. The luminescence of the probe is quenched due to the intramolecular charge transfer (ICT) process, but switched on by a specific recognition reaction between the probe and Cys. [Ir(ppy)2(NTY-bpy)](PF6) shows high sensitivity and selectivity for Cys detection and good biocompatibility. The long-lived emission of [Ir(ppy)2(NTY-bpy)](PF6) allows time-gated luminescence analysis of Cys in cells and human sera. These properties make it convenient for the phosphorescence and time-gated luminescence imaging and flow cytometry analysis of Cys in live samples. The Cys images in cancer cells and inflamed macrophage cells reveal that [Ir(ppy)2(NTY-bpy)](PF6) is distributed in mitochondria after cellular internalization. Visualizations and flow cytometry analysis of mitochondrial Cys levels and Cys-mediated redox activities of live cells are achieved. Using [Ir(ppy)2(NTY-bpy)](PF6) as a probe, in vivo sensing and imaging of Cys in D. magna, zebrafish, and mice are then demonstrated

    Iridium(III) complex-based activatable probe for phosphorescent/time-gated luminescent sensing and imaging of cysteine in mitochondria of live cells and animals

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    This study reports an activatable iridium(III) complex probe for phosphorescence/time-gated luminescence detection of cysteine (Cys) in vitro and in vivo. The probe, [Ir(ppy)2(NTY-bpy)](PF6), is developed by incorporating a strong electron withdrawing group, nitroolefin, into a bipyridine ligand of the Ir(III) complex. The luminescence of the probe is quenched due to the intramolecular charge transfer (ICT) process, but switched on by a specific recognition reaction between the probe and Cys. [Ir(ppy)2(NTY-bpy)](PF6) shows high sensitivity and selectivity for Cys detection and good biocompatibility. The long-lived emission of [Ir(ppy)2(NTY-bpy)](PF6) allows time-gated luminescence analysis of Cys in cells and human sera. These properties make it convenient for the phosphorescence and time-gated luminescence imaging and flow cytometry analysis of Cys in live samples. The Cys images in cancer cells and inflamed macrophage cells reveal that [Ir(ppy)2(NTY-bpy)](PF6) is distributed in mitochondria after cellular internalization. Visualizations and flow cytometry analysis of mitochondrial Cys levels and Cys-mediated redox activities of live cells are achieved. Using [Ir(ppy)2(NTY-bpy)](PF6) as a probe, in vivo sensing and imaging of Cys in D. magna, zebrafish, and mice are then demonstrated

    Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses

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    Hydrogen sulfide (H2S) has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0ā€‰mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2āˆ™-) in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX) and catalase (CAT) and decreased those of lipoxygenase (LOX) in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation
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