32 research outputs found

    Antifungal Activity and Action Mechanism of Ginger Oleoresin Against Pestalotiopsis microspora Isolated From Chinese Olive Fruits

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    Pestalotiopsis microspora (P. microspora) is one of dominant pathogenic fungi causing rotten disease in harvested Chinese olive (Canarium album Lour.) fruits. The purposes of this study were to evaluate the antifungal activities of ginger oleoresin (GO) against P. microspora and to illuminate the underlying action mechanisms. The in vitro assays indicate that GO exhibited strong antifungal activity against mycelial growth of P. microspore, and with 50%-inhibition concentration (EC50) and 90%-inhibition concentration (EC90) at 2.04 μL GO and 8.87 μL GO per mL propylene glycol, respectively, while the minimal inhibitory concentration (MIC) and minimal fungicidal concentration were at 10 μL GO and 30 μL GO per mL propylene glycol, respectively. Spore germination of P. microspora was inhibited by GO in a dose-dependent manner, and with 100% inhibition rate at the concentration of 8 μL GO per mL propylene glycol. Compared to the control, the cellular membrane permeability of P. microspora increased due to severe leakage of intercellular electrolytes, soluble proteins, and total sugars with the treatments (EC50, EC90) by GO during incubation. In addition, analysis of fatty acid contents and compositions in cellular membrane by GC-MS indicated that GO could significantly promote the degradation or peroxidation of unsaturated fatty acids in P. microspore, resulting in the enhancement of membrane fluidity. Moreover, observations of microstructure further showed the damage to plasma membrane and morphology of P. microspora caused by GO, which resulted in distortion, sunken and shriveled spores and mycelia of the pathogen. Furthermore, in vivo assay confirmed that over 3 MIC GO treatments remarkably suppressed disease development in P. microspore inoculated-Chinese olive fruit. These results demonstrate that owing to its strong antifungal activity, GO can be used as a promising antifungal agent to inhibit the growth of pathogenic fungi in Chinese olives

    Degradation of Internalized αvβ5 Integrin Is Controlled by uPAR Bound uPA: Effect on β1 Integrin Activity and α-SMA Stress Fiber Assembly

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    Myofibroblasts (Mfs) that persist in a healing wound promote extracellular matrix (ECM) accumulation and excessive tissue contraction. Increased levels of integrin αvβ5 promote the Mf phenotype and other fibrotic markers. Previously we reported that maintaining uPA (urokinase plasminogen activator) bound to its cell-surface receptor, uPAR prevented TGFβ-induced Mf differentiation. We now demonstrate that uPA/uPAR controls integrin β5 protein levels and in turn, the Mf phenotype. When cell-surface uPA was increased, integrin β5 levels were reduced (61%). In contrast, when uPA/uPAR was silenced, integrin β5 total and cell-surface levels were increased (2–4 fold). Integrin β5 accumulation resulted from a significant decrease in β5 ubiquitination leading to a decrease in the degradation rate of internalized β5. uPA-silencing also induced α-SMA stress fiber organization in cells that were seeded on collagen, increased cell area (1.7 fold), and increased integrin β1 binding to the collagen matrix, with reduced activation of β1. Elevated cell-surface integrin β5 was necessary for these changes after uPA-silencing since blocking αvβ5 function reversed these effects. Our data support a novel mechanism by which downregulation of uPA/uPAR results in increased integrin αvβ5 cell-surface protein levels that regulate the activity of β1 integrins, promoting characteristics of the persistent Mf

    Genome-Wide Identification and Immune Response Analysis of Serine Protease Inhibitor Genes in the Silkworm, Bombyx mori

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    In most insect species, a variety of serine protease inhibitors (SPIs) have been found in multiple tissues, including integument, gonad, salivary gland, and hemolymph, and are required for preventing unwanted proteolysis. These SPIs belong to different families and have distinct inhibitory mechanisms. Herein, we predicted and characterized potential SPI genes based on the genome sequences of silkworm, Bombyx mori. As a result, a total of eighty SPI genes were identified in B. mori. These SPI genes contain 10 kinds of SPI domains, including serpin, Kunitz_BPTI, Kazal, TIL, amfpi, Bowman-Birk, Antistasin, WAP, Pacifastin, and alpha-macroglobulin. Sixty-three SPIs contain single SPI domain while the others have at least two inhibitor units. Some SPIs also contain non-inhibitor domains for protein-protein interactions, including EGF, ADAM_spacer, spondin_N, reeler, TSP_1 and other modules. Microarray analysis showed that fourteen SPI genes from lineage-specific TIL family and Group F of serpin family had enriched expression in the silk gland. The roles of SPIs in resisting pathogens were investigated in silkworms when they were infected by four pathogens. Microarray and qRT-PCR experiments revealed obvious up-regulation of 8, 4, 3 and 3 SPI genes after infection with Escherichia coli, Bacillus bombysepticus, Beauveria bassiana or B. mori nuclear polyhedrosis virus (BmNPV), respectively. On the contrary, 4, 11, 7 and 9 SPI genes were down-regulated after infection with E. coli, B. bombysepticus, B. bassiana or BmNPV, respectively. These results suggested that these SPI genes may be involved in resistance to pathogenic microorganisms. These findings may provide valuable information for further clarifying the roles of SPIs in the development, immune defence, and efficient synthesis of silk gland protein

    Remote sensing image classification method based on evidence theory and decision tree

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    Remote sensing image classification is an important and complex problem. Conventional remote sensing image classification methods are mostly based on Bayesian subjective probability theory, but there are many defects for its uncertainty. This paper firstly introduces evidence theory and decision tree method. Then it emphatically introduces the function of support degree that evidence theory is used on pattern recognition. Combining the D-S evidence theory with the decision tree algorithm, a D-S evidence theory decision tree method is proposed, where the support degree function is the tie. The method is used to classify the classes, such as water, urban land and green land with the exclusive spectral feature parameters as input values, and produce three classification images of support degree. Then proper threshold value is chosen and according image is handled with the method of binarization. Then overlay handling is done with these images according to the type of classifications, finally the initial result is obtained. Then further accuracy assessment will be done. If initial classification accuracy is unfit for the requirement, reclassification for images with support degree of less than threshold is conducted until final classification meets the accuracy requirements. Compared to Bayesian classification, main advantages of this method are that it can perform reclassification and reach a very high accuracy. This method is finally used to classify the land use of Yantai Economic and Technological Development Zone to four classes such as urban land, green land and water, and effectively support the classification. © 2010 Copyright SPIE - The International Society for Optical Engineering

    Estimating the environmental Kuznets curve for ecological footprint at the global level: A spatial econometric approach

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    The national ecological footprint of both consumption and production are significantly spatially autocorrelated at global level. This violates the assumption of independently distributed errors of most conventional estimation techniques. Using a spatial econometric approach, this paper re-examine the relationship between economic growth and environmental impact for indicator of ecological footprint. The results do not show evidence of inverted U-shape Environmental Kuznets Curve. The domestic ecological footprint of consumption (or production) was obviously influenced by the ecological footprint of consumption (or production), income and biocapacity in neighborhood countries. We also found that the consumption footprint is more sensitive to domestic income, while production footprint is more sensitive to domestic biocapacity, which is often unnoticed in EKC hypothesis analyses that focus exclusively on the consumption-based or production-based indictors. (c) 2013 Published by Elsevier Ltd

    Isolation and Structural Characterization of Lignin from Cotton Stalk Treated in an Ammonia Hydrothermal System

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    To investigate the potential for the utilization of cotton stalk, ammonia hydrothermal treatment was applied to fractionate the samples into aqueous ammonia-soluble and ammonia-insoluble portions. The ammonia-soluble portion was purified to yield lignin fractions. The lignin fractions obtained were characterized by wet chemistry (carbohydrate analysis) and spectroscopy methods (FT-IR, 13C and 1H-13C HSQC NMR spectroscopy) as well as gel permeation chromatography (GPC). The results showed that the cotton stalk lignin fractions were almost absent of neutral sugars (0.43%–1.29%) and had relatively low average molecular weights (1255–1746 g/mol). The lignin fractions belonged to typical G-S lignin, which was composed predominately of G-type units (59%) and noticeable amounts of S-type units (40%) together with a small amount of H-type units (~1%). Furthermore, the ammonia-extractable lignin fractions were mainly composed of β-O-4\u27 inter-unit linkages (75.6%), and small quantities of β-β\u27 (12.2%), together with lower amounts of β-5\u27 carbon-carbon linkages (7.4%) and p-hydroxycinnamyl alcohol end groups

    Chemical Conversion Pathways and Kinetic Modeling for the OH-Initiated Reaction of Triclosan in Gas-Phase

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    As a widely used antimicrobial additive in daily consumption, attention has been paid to the degradation and conversion of triclosan for a long time. The quantum chemistry calculation and the canonical variational transition state theory are employed to investigate the mechanism and kinetic property. Besides addition and abstraction, oxidation pathways and further conversion pathways are also considered. The OH radicals could degrade triclosan to phenols, aldehydes, and other easily degradable substances. The conversion mechanisms of triclosan to the polychlorinated dibenzopdioxin and furan (PCDD/Fs) and polychlorinated biphenyls (PCBs) are clearly illustrated and the toxicity would be strengthened in such pathways. Single radical and diradical pathways are compared to study the conversion mechanism of dichlorodibenzo dioxin (DCDD). Furthermore, thermochemistry is discussed in detail. Kinetic property is calculated and the consequent ratio of kadd/ktotal and kabs/ktotal at 298.15 K are 0.955 and 0.045, respectively. Thus, the OH radical addition reactions are predominant, the substitute position of OH radical on triclosan is very important to generate PCDD and furan, and biradical is also a vital intermediate to produce dioxin

    Effect of 2,4-D pre-treatment on quality during ripening of on-tree longan fruit

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    The aim of this study was to investigate the effect of 20 mg/L 2,4-D on the quality during ripening of on-tree longan fruits. We investigated external and internal properties of the on-tree longan fruits. The results showed that 2,4-D treatment promotes the growth based on the fruit size and weight. The respiration rate, contents of TSS, total soluble sugar, sucrose, glucose, fructose, and hexose revealed an increasing tendency with advancing the maturity and reached the high status during 110-126DPA. By contrast, the relative electric conductivity and TA content displayed a declining trend during the ripening stage, increase with the senescence. All these pieces of information indicated that 2,4-D treatment could effectively promote the sensory quality of on-tree longan fruit, prolong the harvest time to 118DPA, while CK should harvest before 110DPA
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