61 research outputs found

    Теоретические основы интенсификации работы грануляционных устройств с усовершенствованной гидродинамикой

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    Одним із способів зменшення габаритів грануляційного обладнання є вдосконалення гідродинамічних умов перебування в ньому дисперсної фази. Цього можна досягти, зокрема, за рахунок застосування вихрових і високотурбулізованних потоків. Представлена робота присвячена обґрунтуванню можливості створення алгоритму управління рухом дисперсної фази в робочому просторі грануляційного пристрою, на підставі якого буде визначена його оптимальна конструкція з мінімальними габаритами.Одним из способов уменьшения габаритов грануляционного оборудования является усовершенствование гидродинамических условий пребывания в нём дисперсной фазы. Этого можно достичь, в частности, за счет применения вихревых и высокотурбулизованных потоков. Представленная работа посвящена обоснованию возможности создания алгоритма управления движением дисперсной фазы в рабочем пространстве грануляционного устройства, на основании которого будет определена его оптимальная конструкция с минимальными габаритами

    Mining Plants for Bacterial Quorum Sensing Modulators

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    The bacterial plant pathogen <i>Agrobacterium tumefaciens</i> uses quorum sensing (QS) in order to regulate the transfer of DNA into the host plant genome, and this results in the induction of crown gall tumors. The deleterious results of these infections are widespread and affect many species of fruit and crops. In order to further our understanding of this process and to provide potential solutions, we evaluated a library of 3800 natural products from plant sources and identified potent compounds that are able to strongly modulate plant–bacterial interactions

    PICA: Pixel Intensity Correlation Analysis for Deconvolution and Metabolite Identification in Mass Spectrometry Imaging

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    In-source fragmentation (ISF) is a naturally occurring phenomenon in various ion sources including soft ionization techniques such as matrix-assisted laser desorption/ionization (MALDI). It has traditionally been minimized as it makes the dataset more complex and often leads to mis-annotation of metabolites. Here, we introduce an approach termed PICA (for pixel intensity correlation analysis) that takes advantage of ISF in MALDI imaging to increase confidence in metabolite identification. In PICA, the extraction and association of in-source fragments to their precursor ion results in “pseudo-MS/MS spectra” that can be used for identification. We examined PICA using three different datasets, two of which were published previously and included validated metabolites annotation. We show that highly colocalized ions possessing Pearson correlation coefficient (PCC) ≥ 0.9 for a given precursor ion are mainly its in-source fragments, natural isotopes, adduct ions, or multimers. These ions provide rich information for their precursor ion identification. In addition, our results show that moderately colocalized ions (PCC < 0.9) may be structurally related to the precursor ion, which allows for the identification of unknown metabolites through known ones. Finally, we propose three strategies to reduce the total computation time for PICA in MALDI imaging. To conclude, PICA provides an efficient approach to extract and group ions stemming from the same metabolites in MALDI imaging and thus allows for high-confidence metabolite identification

    PICA: Pixel Intensity Correlation Analysis for Deconvolution and Metabolite Identification in Mass Spectrometry Imaging

    No full text
    In-source fragmentation (ISF) is a naturally occurring phenomenon in various ion sources including soft ionization techniques such as matrix-assisted laser desorption/ionization (MALDI). It has traditionally been minimized as it makes the dataset more complex and often leads to mis-annotation of metabolites. Here, we introduce an approach termed PICA (for pixel intensity correlation analysis) that takes advantage of ISF in MALDI imaging to increase confidence in metabolite identification. In PICA, the extraction and association of in-source fragments to their precursor ion results in “pseudo-MS/MS spectra” that can be used for identification. We examined PICA using three different datasets, two of which were published previously and included validated metabolites annotation. We show that highly colocalized ions possessing Pearson correlation coefficient (PCC) ≥ 0.9 for a given precursor ion are mainly its in-source fragments, natural isotopes, adduct ions, or multimers. These ions provide rich information for their precursor ion identification. In addition, our results show that moderately colocalized ions (PCC < 0.9) may be structurally related to the precursor ion, which allows for the identification of unknown metabolites through known ones. Finally, we propose three strategies to reduce the total computation time for PICA in MALDI imaging. To conclude, PICA provides an efficient approach to extract and group ions stemming from the same metabolites in MALDI imaging and thus allows for high-confidence metabolite identification

    Overexpression of <i>AtSHN1/WIN1</i> Provokes Unique Defense Responses

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    <div><p>The plant cell cuticle serves as the first barrier protecting plants from mechanical injury and invading pathogens. The cuticle can be breached by cutinase-producing pathogens and the degradation products may activate pathogenesis signals in the invading pathogens. Cuticle degradation products may also trigger the plant’s defense responses. <i>Botrytis cinerea</i> is an important plant pathogen, capable of attacking and causing disease in a wide range of plant species. <i>Arabidopsis thaliana shn1-1D</i> is a gain-of-function mutant, which has a modified cuticular lipid composition. We used this mutant to examine the effect of altering the whole-cuticle metabolic pathway on plant responses to <i>B. cinerea</i> attack. Following infection with <i>B. cinerea</i>, the <i>shn1-1D</i> mutant discolored more quickly, accumulated more H<sub>2</sub>O<sub>2</sub>, and showed accelerated cell death relative to wild-type (WT) plants. Whole transcriptome analysis of <i>B. cinerea</i>-inoculated <i>shn1-1D</i> vs. WT plants revealed marked upregulation of genes associated with senescence, oxidative stress and defense responses on the one hand, and genes involved in the magnitude of defense-response control on the other. We propose that altered cutin monomer content and composition of <i>shn1-1D</i> plants triggers excessive reactive oxygen species accumulation and release which leads to a strong, unique and uncontrollable defense response, resulting in plant sensitivity and death.</p></div
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