41 research outputs found

    Effects of Inflorescence Stem Structure and Cell Wall Components on the Mechanical Strength of Inflorescence Stem in Herbaceous Peony

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    Herbaceous peony (Paeonia lactiflora Pall.) is a traditional famous flower, but its poor inflorescence stem quality seriously constrains the development of the cut flower. Mechanical strength is an important characteristic of stems, which not only affects plant lodging, but also plays an important role in stem bend or break. In this paper, the mechanical strength, morphological indices and microstructure of P. lactiflora development inflorescence stems were measured and observed. The results showed that the mechanical strength of inflorescence stems gradually increased, and that the diameter of inflorescence stem was a direct indicator in estimating mechanical strength. Simultaneously, with the development of inflorescence stem, the number of vascular bundles increased, the vascular bundle was arranged more densely, the sclerenchyma cell wall thickened, and the proportion of vascular bundle and pith also increased. On this basis, cellulose and lignin contents were determined, PlCesA3, PlCesA6 and PlCCoAOMT were isolated and their expression patterns were examined including PlPAL. The results showed that cellulose was not strictly correlated with the mechanical strength of inflorescence stem, and lignin had a significant impact on it. In addition, PlCesA3 and PlCesA6 were not key members in cellulose synthesis of P. lactiflora and their functions were also different, but PlPAL and PlCCoAOMT regulated the lignin synthesis of P. lactiflora. These data indicated that PlPAL and PlCCoAOMT could be applied to improve the mechanical strength of P. lactiflora inflorescence stem in genetic engineering

    Singly Flagellated Pseudomonas Aeruginosa Chemotaxes Efficiently by Unbiased Motor Regulation

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    Pseudomonas aeruginosa is an opportunistic human pathogen that has long been known to chemotax. More recently, it has been established that chemotaxis is an important factor in the ability of P. aeruginosa to make biofilms. Genes that allow P. aeruginosa to chemotax are homologous with genes in the paradigmatic model organism for chemotaxis, Escherichia coli. However, P. aeruginosa is singly flagellated and E. coli has multiple flagella. Therefore, the regulation of counterclockwise/ clockwise flagellar motor bias that allows E. coli to efficiently chemotax by runs and tumbles would lead to inefficient chemotaxis by P. aeruginosa, as half of a randomly oriented population would respond to a chemoattractant gradient in the wron sense. How P. aeruginosa regulates flagellar rotation to achieve chemotaxis is not known. Here, we analyze the swimming trajectories of single cells in microfluidic channels and the rotations of cells tethered by their flagella to the surface of a variableenvironment flow cell. We show that P. aeruginosa chemotaxes by symmetrically increasing the durations of both counterclockwise and clockwise flagellar rotations when swimming up the chemoattractant gradient and symmetrically decreasing rotation durations when swimming down the chemoattractant gradient. Unlike the case for E. coli, the counterclockwise/clockwise bias stays constant for P. aeruginosa. We describe P. aeruginosa’s chemotaxis using an analytical model for symmetric motor regulation. We use this model to do simulations that show that, given P. aeruginosa’s physiological constraints on motility, its distinct, symmetric regulation of motor switching optimizes chemotaxis.This work, including the efforts of Vernita Gordon, was funded by UT Austin (startup funds). This work, including the efforts of Qi Ouyang, Chunxiong Luo, and Zhaojun Li, was funded by NSF of China (11174012 and 11434001). This work, including the efforts of Qiuxian Cai, was funded by China Scholarship Council (CSC) (fellowship). This work, including the efforts of Vernita Gordon, was funded by the Exxon Mobil Corporation (gift).Center for Nonlinear Dynamic

    The lagged effect of air pollution on human eosinophils: a distributed lag non-linear model

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    ObjectivesThe aim of this study was to determine the lag between exposure to air pollutants and changes in human eosinophil counts.Material and MethodsThis was a retrospective study employing 246 425 physical examination records dated December 2013 – December 2016 from Chengdu, China. The authors determined the prevalence of individuals with eosinophil counts above the normal reference range each day. A distributed lag non-linear model was used to evaluate the lagged effect of each air pollutant on eosinophil counts. The lagged effects of each air pollutant were counted and presented with smoothing splines.ResultsThe effects of air pollutants such as particulate matter (PM2.5, aerodynamic diameters <2.5 μm; PM10, aerodynamic diameters <10 μm), nitrogen dioxide (NO2) and ozone (O3) were evaluated. In women, the effects of PM2.5 (RR = 1.154, 95% CI: 1.061–1.255) and PM10 (RR = 1.309, 95% CI: 1.130–1.517) reached the maximum values on lag day 0. In men, there was no significant effect of PM2.5, but significant effects of PM10 were found for lag days 20–28. The effects of NO2 and O3 on eosinophils were not statistically significant for either gender.ConclusionsThe air pollutants of PM10 have a significant effect on human eosinophils for both women and men, but with different temporal patterns, with women showing a lag of 0–5 days and men showing a lag of 20–28 days. In addition, PM2.5 was significant for women with a lag of 0–3 days but it was not significant for men

    Application of Extended Set Pair Analysis on Wear Risk Evaluation of Backfill Pipeline

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    Filling slurry can inevitably cause irreversible wear to the pipeline, which represents great costs to mines. This study aims to propose an extended set pair analysis (SPA) for the wear risk evaluation of backfill pipeline. First, to fully describe the wear risk of backfill pipeline, an evaluation index system was established from the aspects of slurry characteristics, pipeline properties, and slurry flow state. Then, the experts grading method was modified with probabilistic linguistic term sets (PLTSs) to obtain subjective weights. Meanwhile, the criteria importance through intercriteria correlation (CRITIC) approach was used to calculate objective weights. By introducing a preference coefficient, they were integrated to determine the comprehensive weights. After that, the classical SPA was extended with membership functions and fuzzy entropy theory, so that the wear risk of backfill pipeline can be evaluated from the perspectives of both the risk level and complexity. Finally, the proposed methodology was applied to assess the wear risk in the Jinchuan nickel mine, Dahongshan copper mine, Hedong gold mine, and Xincheng gold mine. The reliability of evaluation results was further verified through sensitivity and comparative analyses. Results indicate that the proposed methodology is feasible for the wear risk evaluation of backfill pipeline, and can provide guidance on the wear risk management

    Application of Extended Set Pair Analysis on Wear Risk Evaluation of Backfill Pipeline

    No full text
    Filling slurry can inevitably cause irreversible wear to the pipeline, which represents great costs to mines. This study aims to propose an extended set pair analysis (SPA) for the wear risk evaluation of backfill pipeline. First, to fully describe the wear risk of backfill pipeline, an evaluation index system was established from the aspects of slurry characteristics, pipeline properties, and slurry flow state. Then, the experts grading method was modified with probabilistic linguistic term sets (PLTSs) to obtain subjective weights. Meanwhile, the criteria importance through intercriteria correlation (CRITIC) approach was used to calculate objective weights. By introducing a preference coefficient, they were integrated to determine the comprehensive weights. After that, the classical SPA was extended with membership functions and fuzzy entropy theory, so that the wear risk of backfill pipeline can be evaluated from the perspectives of both the risk level and complexity. Finally, the proposed methodology was applied to assess the wear risk in the Jinchuan nickel mine, Dahongshan copper mine, Hedong gold mine, and Xincheng gold mine. The reliability of evaluation results was further verified through sensitivity and comparative analyses. Results indicate that the proposed methodology is feasible for the wear risk evaluation of backfill pipeline, and can provide guidance on the wear risk management

    Revealing ion transport in supercapacitors with Sub-2 nm two-dimensional graphene channels

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    Unique ion transport behaviors in two-dimensional (2D) nanochannels have sparked strong interests in exploring 2D nanomaterials for supercapacitor applications, which rely much on the formation of electric double layers (EDLs) at the solid-liquid interface. However, there is still a crucial missing part on understanding how ions with different kinetic properties could affect the formation of EDLs. Here, we examine the real-time ion transport in the formation of EDLs by electrochemical quartz crystal microbalance (EQCM) and observe distinct charge transport behaviors between activated carbon with a tortuous pore structure and graphene films with 2D channel spacing (<2 nm). Using molecular dynamics (MD) simulations, we find that ions with a higher diffusion coefficient predominantly affect the EDLs formation, leading to the anion- or cation-dominated ion exchange process in the sub-2 nm 2D graphene channels. By expanding to different electrolytes, the kinetics-controlled ion transport mechanism is further confirmed by experimental observations and MD simulations. Such findings will bring new insights for improved electrochemical performance of 2D nanomaterials.</p

    The neuronal p35 activator of Cdk5 is a novel F-actin binding and bundling protein

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    The neuronal Cdk5 activator p35 is involved in a multitude of neuronal activities, including cytoskeletal organization. We show here that p35 directly interacts with filamentous actin (F-actin) but not with monomeric actin (G-actin). Through binding, p35 induces the formation of actin bundles and stabilizes F-actin against dilution-induced depolymerization. p35 forms intermolecular self-associations, suggesting that p35 cross-links actin filaments into bundles via its intermolecular self-association. p35 dimerization and association with F-actin occur at the N-terminal region that is absent in the calpain-cleaved product p25, indicating that such p35 properties are lost by its truncation induced under neurotoxic conditions. Using p35 phosphorylated by Cdk5 and a mutational approach, we demonstrate that the phosphorylation of p35 promotes its homodimerization and p35-induced formation of F-actin bundles. In addition, the phosphorylation regulates p35 distribution to microtubule and actin cytoskeletons. Together, these observations define a novel function for p35 in cytoskeletal regulation

    The role of atorvastatin in suppressing tumor growth of uterine fibroids

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    Abstract Background Medical therapeutic options remain quite limited for uterine fibroids treatment. Statins, competitive inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, have anti-tumoral effects on multiple cancer types, however, little is known about their effects on uterine fibroids. Methods Initially, we conducted a retrospective study of 120 patients with uterine fibroids and hyperlipidemia from the Second Affiliated Hospital of Wenzhou Medical University. Then, we evaluated the effect of atorvastatin on proliferation and apoptosis both in immortalized uterine fibroids cells and primary uterine fibroids cells. Furthermore, the molecular mechanism by which atorvastatin suppressed uterine fibroids cell growth was explored. Results Our results showed that atorvastatin use for 1 or 2 years significantly suppressed growth of uterine fibroids. Atorvastatin inhibited the proliferation of immortalized and primary uterine fibroids cells in a dose and time-dependent manner and stimulated apoptosis of uterine fibroids cells by inducing caspase-3 activation, up-regulating Bim and down-regulating Bcl-2. Additionally, atorvastatin treatment suppressed phosphorylation of ERK1/2 and JNK. Furthermore, GGPP, a downstream lipid isoprenoid intermediate, significantly rescued the effect of atorvastatin. Conclusions These results suggest that atorvastatin exerts anti-tumoral effects on uterine fibroids through inhibition of cell proliferation and induction of apoptosis in HMG-CoA-dependent pathway. Our results provide the first clinical and preclinical data on the use of atorvastatin as a promising nonsurgical treatment option for uterine fibroids

    Electrodeposited cobalt sulfide on a vertical graphene nanocomposite for high-performance supercapacitors

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    Cobalt sulfide (CoS) has been widely applied in the development of high-performance supercapacitors. However, the morphological stability of CoS remains an issue during the charging–discharging processes. Herein, vertical graphene is introduced via facile electrodeposition to support CoS for the design of high-performance and stable electrodes. Since vertical graphene has a unique three-dimensional (3D) porous structure, good mechanical rigidity, and high electrical conductivity, the nanostructured CoS is tightly anchored on the vertical graphene, leading to improvement of the specific capacitance. The CoS/VG composites exhibit an impressive specific capacitance of 2649.25 F g−1 at a current density of 1 A g−1, and a drastic 150.7% retention after 3000 cycles at a current density of 10 A g−1. Such high-performance and stable CoS/VG electrodes in this work demonstrate great prospects for the development of high-performance and stable supercapacitors in a cost-effective manner.</p
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