481 research outputs found

    Allelopathy of root exudates from different resistant eggplants to Verticillium dahliae and the identification of allelochemicals

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    Three eggplant cultivars were inoculated with Verticillium dahliae Kleb. to assess their resistance to Verticillium wilt. Solanum tor was resistant, “Liyuanziqie” was tolerant, and “Xi’anlvqie” susceptible. The disease incidence and disease index of Verticillium wilt and the amount of V. dahliae in rhizospheric soil, variation of microbial composition, the allelopathy of root exudates to mycelium growth of V. dahliae and the chemical substances of root exudates from eggplant cultivars with different resistance to Verticillium wilt were investigated in this experiment. The results showed that the root exudates of resistant type could not only affect the growth and development of V. dahliae, but also influence V. dahliae indirectly through regulating soil microbial community composition. This may be one of the reasons for the increase of disease resistance. However, the susceptible type exhibited an opposite trend. It was inferred that the resistant type contained some particular components, such as  acohd, amide, pyranoid, fluorene, while the susceptible one comprised more types of components, that is, ketone, phenol, ester and phenolic acid.Key words: Allelopathy, allelochemical, root exudates, eggplant, Verticillium dahliae, Verticillium wilt, microbial composition

    Spatio-Temporal Characteristics of Global Warming in the Tibetan Plateau during the Last 50 Years Based on a Generalised Temperature Zone - Elevation Model

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    Temperature is one of the primary factors influencing the climate and ecosystem, and examining its change and fluctuation could elucidate the formation of novel climate patterns and trends. In this study, we constructed a generalised temperature zone elevation model (GTEM) to assess the trends of climate change and temporal-spatial differences in the Tibetan Plateau (TP) using the annual and monthly mean temperatures from 1961-2010 at 144 meteorological stations in and near the TP. The results showed the following: (1) The TP has undergone robust warming over the study period, and the warming rate was 0.318°C/decade. The warming has accelerated during recent decades, especially in the last 20 years, and the warming has been most significant in the winter months, followed by the spring, autumn and summer seasons. (2) Spatially, the zones that became significantly smaller were the temperature zones of -6°C and -4°C, and these have decreased 499.44 and 454.26 thousand sq km from 1961 to 2010 at average rates of 25.1% and 11.7%, respectively, over every 5-year interval. These quickly shrinking zones were located in the northwestern and central TP. (3) The elevation dependency of climate warming existed in the TP during 1961-2010, but this tendency has gradually been weakening due to more rapid warming at lower elevations than in the middle and upper elevations of the TP during 1991-2010. The higher regions and some low altitude valleys of the TP were the most significantly warming regions under the same categorizing criteria. Experimental evidence shows that the GTEM is an effective method to analyse climate changes in high altitude mountainous regions

    Understanding the dynamics of Toll-like Receptor 5 response to flagellin and its regulation by estradiol

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    © 2017 The Author(s). Toll-like receptors (TLRs) are major players of the innate immune system. Once activated, they trigger a signalling cascade that leads to NF-ΰ B translocation from the cytoplasm to the nucleus. Single cell analysis shows that NF-ΰ B signalling dynamics are a critical determinant of transcriptional regulation. Moreover, the outcome of innate immune response is also affected by the cross-talk between TLRs and estrogen signalling. Here, we characterized the dynamics of TLR5 signalling, responsible for the recognition of flagellated bacteria, and those changes induced by estradiol in its signalling at the single cell level. TLR5 activation in MCF7 cells induced a single and sustained NF-k B translocation into the nucleus that resulted in high NF-k B transcription activity. The overall magnitude of NF-k B transcription activity was not influenced by the duration of the stimulus. No significant changes are observed in the dynamics of NF-k B translocation to the nucleus when MCF7 cells are incubated with estradiol. However, estradiol significantly decreased NF-k B transcriptional activity while increasing TLR5-mediated AP-1 transcription. The effect of estradiol on transcriptional activity was dependent on the estrogen receptor activated. This fine tuning seems to occur mainly in the nucleus at the transcription level rather than affecting the translocation of the NF-k B transcription factor

    Shell-Controlled Photoluminescence in CdSe/CNT Nanohybrids

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    A new type of nanohybrids containing carbon nanotubes (CNTs) and CdSe quantum dots (QDs) was prepared using an electrostatic self-assembly method. The CdSe QDs were capped by various mercaptocarboxylic acids, including thioglycolic acid (TGA), dihydrolipoic acid (DHLA) and mercaptoundecanoic acid (MUA), which provide shell thicknesses of ~5.2, 10.6 and 15.2 Å, respectively. The surface-modified CdSe QDs are then self-assembled onto aridine orange-modified CNTs via electrostatic interaction to give CdSe/CNT nanohybrids. The photoluminescence (PL) efficiencies of the obtained nanohybrids increase significantly with the increase of the shell thickness, which is attributed to a distance-dependent photo-induced charge-transfer mechanism. This work demonstrates a simple mean for fine tuning the PL properties of the CdSe/CNT nanohybrids and gains new insights to the photo-induced charge transfer in such nanostructures

    SUMOylation Represses Nanog Expression via Modulating Transcription Factors Oct4 and Sox2

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    Nanog is a pivotal transcription factor in embryonic stem (ES) cells and is essential for maintaining the pluripotency and self-renewal of ES cells. SUMOylation has been proved to regulate several stem cell markers' function, such as Oct4 and Sox2. Nanog is strictly regulated by Oct4/Sox2 heterodimer. However, the direct effects of SUMOylation on Nanog expression remain unclear. In this study, we reported that SUMOylation repressed Nanog expression. Depletion of Sumo1 or its conjugating enzyme Ubc9 increased the expression of Nanog, while high SUMOylation reduced its expression. Interestingly, we found that SUMOylation of Oct4 and Sox2 regulated Nanog in an opposing manner. SUMOylation of Oct4 enhanced Nanog expression, while SUMOylated Sox2 inhibited its expression. Moreover, SUMOylation of Oct4 by Pias2 or Sox2 by Pias3 impaired the interaction between Oct4 and Sox2. Taken together, these results indicate that SUMOylation has a negative effect on Nanog expression and provides new insights into the mechanism of SUMO modification involved in ES cells regulation

    Downgrading MELD Improves the Outcomes after Liver Transplantation in Patients with Acute-on-Chronic Hepatitis B Liver Failure

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    Background: High score of model for end-stage liver diseases (MELD) before liver transplantation (LT) indicates poor prognosis. Artificial liver support system (ALSS) has been proved to effectively improve liver and kidney functions, and thus reduce the MELD score. We aim to evaluate whether downgrading MELD score could improve patient survival after LT. Methodology/Principal Findings: One hundred and twenty-six LT candidates with acute-on-chronic hepatitis B liver failure and MELD score 30wereincludedinthisprospectivestudy.Ofthe126patients,42receivedemergencyLTwithin72h(ELTgroup)andtheother84weregivenALSSassalvagetreatment.Ofthe84patients,33werefoundtohavereducedMELDscore(,30)onthedayofLT(DGMgroup),51underwentLTwithpersistenthighMELDscore(NDGMgroup).Themedianwaitingtimeforadonorwas10forDGMgroupand9.5daysforNDGMgroup.InNDGMgroupthereisasignificantlyhigheroverallmortality(43.130 were included in this prospective study. Of the 126 patients, 42 received emergency LT within 72 h (ELT group) and the other 84 were given ALSS as salvage treatment. Of the 84 patients, 33 were found to have reduced MELD score (,30) on the day of LT (DGM group), 51 underwent LT with persistent high MELD score (N-DGM group). The median waiting time for a donor was 10 for DGM group and 9.5 days for N-DGM group. In N-DGM group there is a significantly higher overall mortality (43.1%) than that in ELT group (16.7%) and DGM group (15.2%). N-DGM (vs. ECT and DGM) was the only independent risk factor of overall mortality (P = 0.003). Age.40 years and the interval from last ALSS to LT.48 h were independent negative influence factors of downgrading MELD. Conclusions/Significance: Downgrading MELD for liver transplant candidates with MELD score 30 was effective i

    Quantum-Dot Light-Emitting Diodes with Nitrogen-Doped Carbon Nanodot Hole Transport and Electronic Energy Transfer Layer

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    Electroluminescence efficiency is crucial for the application of quantum-dot light-emitting diodes (QD-LEDs) in practical devices. We demonstrate that nitrogen-doped carbon nanodot (N-CD) interlayer improves electrical and luminescent properties of QD-LEDs. The N-CDs were prepared by solution-based bottom up synthesis and were inserted as a hole transport layer (HTL) between other multilayer HTL heterojunction and the red-QD layer. The QD-LEDs with N-CD interlayer represented superior electrical rectification and electroluminescent efficiency than those without the N-CD interlayer. The insertion of N-CD layer was found to provoke the Forster resonance energy transfer (FRET) from N-CD to QD layer, as confirmed by time-integrated and - resolved photoluminescence spectroscopy. Moreover, hole-only devices (HODs) with N-CD interlayer presented high hole transport capability, and ultraviolet photoelectron spectroscopy also revealed that the N-CD interlayer reduced the highest hole barrier height. Thus, more balanced carrier injection with sufficient hole carrier transport feasibly lead to the superior electrical and electroluminescent properties of the QD-LEDs with N-CD interlayer. We further studied effect of N-CD interlayer thickness on electrical and luminescent performances for high-brightness QD-LEDs. The ability of the N-CD interlayer to improve both the electrical and luminescent characteristics of the QD-LEDs would be readily exploited as an emerging photoactive material for high-efficiency optoelectronic devices.ope
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