42 research outputs found

    Design of simulator for seepage detection in an embankment based on distributed optic fibre sensing technology

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    Based on the temperature change in an embankment, a seepage flow simulator and monitoring system based on distributed optical fiber sensing are proposed. A simulator is designed that consists of scale model of embankment with definite length, seepage flow control cell and monitoring cell. Conventional hygrothermograph and flowmeter are employed in system dispersedly. The results from those conventional instruments were used to compare with the data from a distributed fibre sensing DiTeSt analyzer. The simulator equipment can monitor various embankments with different boundary conditions, such as temperature, distributions of soakage line and scales. The process of producing seepage pathway and configuration of sensing cable are presented, as well as test results with a field-installed fiber optic sensing cable. The simulator and results are helpful to build reasonable configurations for field real-time monitoring of abnormal seepage flow, which also offer an effective approach to study problems related to a secured embankment

    C. elegans fatty acid two-hydroxylase regulates intestinal homeostasis by affecting heptadecenoic acid production

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    Background/Aims: The hydroxylation of fatty acids at the C-2 position is the first step of fatty acid α-oxidation and generates sphingolipids containing 2-hydroxy fatty acyl moieties. Fatty acid 2-hydroxylation is catalyzed by Fatty acid 2-hydroxylase (FA2H) enzyme. However, the precise roles of FA2H and fatty acid 2-hydroxylation in whole cell homeostasis still remain unclear. Methods: Here we utilize Caenorhabditis elegans as the model and systemically investigate the physiological functions of FATH-1/C25A1.5, the highly conserved worm homolog for mammalian FA2H enzyme. Immunostaining, dye-staining and translational fusion reporters were used to visualize FATH-1 protein and a variety of subcellular structures. The “click chemistry” method was employed to label 2-OH fatty acid in vivo. Global and tissue-specific RNAi knockdown experiments were performed to inactivate FATH-1 function. Lipid analysis of the fath-1 deficient mutants was achieved by mass spectrometry. Results: C. elegans FATH-1 is expressed at most developmental stages and in most tissues. Loss of fath-1 expression results in severe growth retardation and shortened lifespan. FATH-1 function is crucially required in the intestine but not the epidermis with stereospecificity. The “click chemistry” labeling technique showed that the FATH-1 metabolites are mainly enriched in membrane structures preferable to the apical side of the intestinal cells. At the subcellular level, we found that loss of fath-1 expression inhibits lipid droplets formation, as well as selectively disrupts peroxisomes and apical endosomes. Lipid analysis of the fath-1 deficient animals revealed a significant reduction in the content of heptadecenoic acid, while other major FAs remain unaffected. Feeding of exogenous heptadecenoic acid (C17: 1), but not oleic acid (C18: 1), rescues the global and subcellular defects of fath-1 knockdown worms. Conclusion: Our study revealed that FATH-1 and its catalytic products are highly specific in the context of chirality, C-chain length, spatial distribution, as well as the types of cellular organelles they affect. Such an unexpected degree of specificity for the synthesis and functions of hydroxylated FAs helps to regulate protein transport and fat metabolism, therefore maintaining the cellular homeostasis of the intestinal cells. These findings may help our understanding of FA2H functions across species, and offer potential therapeutical targets for treating FA2H-related diseases

    Air-stable bismuth sulfobromide (BiSBr) visible-light absorbers : optoelectronic properties and potential for energy harvesting

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    ns2 compounds have recently attracted considerable interest due to their potential to replicate the defect tolerance of lead-halide perovskites and overcome their toxicity and stability limitations. However, only a handful of compounds beyond the perovskite family have been explored thus far. Herein, we investigate bismuth sulfobromide (BiSBr), which is a quasi-one-dimensional semiconductor, but very little is known about its optoelectronic properties or how it can be processed as thin films. We develop a solution processing route to achieve phase-pure, stoichiometric BiSBr films (ca. 240 nm thick), which we show to be stable in ambient air for over two weeks without encapsulation. The bandgap (1.91 ± 0.06 eV) is ideal for harvesting visible light from common indoor light sources, and we calculate the optical limit in efficiency (i.e., spectroscopic limited maximum efficiency, SLME) to be 43.6% under 1000 lux white light emitting diode illumination. The photoluminescence lifetime is also found to exceed the 1 ns threshold for photovoltaic absorber materials worth further development. Through X-ray photoemission spectroscopy and Kelvin probe measurements, we find the BiSBr films grown to be n-type, with an electron affinity of 4.1 ± 0.1 eV and ionization potential of 6.0 ± 0.1 eV, which are compatible with a wide range of established charge transport layer materials. This work shows BiSBr to hold promise for indoor photovoltaics, as well as other visible-light harvesting applications, such as photoelectrochemical cells, or top-cells for tandem photovoltaics

    Precision immunization: a new trend in human vaccination

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    Vaccination has been one of the major revolutions in the history of human health. Vaccination programs have targeted entire populations such as infants or elderly subjects as a matter of being efficient with time and resources. These general populations are heterogeneous in terms of factors such as ethnicity, health status, and socio-economics. Thus, there have been variations in the safety and effectiveness profiles of certain vaccinations according to current population-wide strategies. As the concept of precision medicine has been raised in recent years, many researchers have suggested that vaccines could be administered more precisely in terms of particular target populations, vaccine formulations, regimens, and dosage levels. This review addresses the concept and framework of precision immunization, summarizes recent and representative clinical trials of among specific populations, mentions important factors to be addressed in customizing vaccinations, and provides suggestions on the establishment of precision immunization with the goal of maximizing the effectiveness of vaccines in general

    Silencing of a Cotton Actin-Binding Protein GhWLIM1C Decreases Resistance against <i>Verticillium dahliae</i> Infection

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    LIM proteins are widely spread in various types of plant cells and play diversely crucial cellular roles through actin cytoskeleton assembly and gene expression regulation. Till now, it has not been clear whether LIM proteins function in plant pathogen defense. In this study, we characterized a LIM protein, GhWLIM1C, in upland cotton (Gossypium hirsutum). We found that GhWLIM1C could bind and bundle the actin cytoskeleton, and it contains two LIM domains (LIM1 and LIM2). Both the two domains could bind directly to the actin filaments. Moreover, the LIM2 domain additionally bundles the actin cytoskeleton, indicating that it possesses a different biochemical activity than LIM1. The expression of GhWLIM1C responds to the infection of the cotton fungal pathogen Verticillium dahliae (V. dahliae). Silencing of GhWLIM1C decreased cotton resistance to V. dahliae. These may be associated with the down regulated plant defense response, including the PR genes expression and ROS accumulation in the infected cotton plants. In all, these results provide new evidence that a plant LIM protein functions in plant pathogen resistance and the assembly of the actin cytoskeleton are closely related to the triggering of the plant defense response

    Analysis of epidemiological serosurvey of hepatitis B virus among people under 29 years of age in Jiangsu Province, China

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    Background: The purpose of this paper was to analyze the prevalence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core anti-body (anti-HBc)in1-29 years old living in the most populous eastern province of China,22 years after introduction of hepatitis B vaccine (HepB) vaccination of infants and provide provincial baseline data for developping a better prevention and control plan for hepatitis B virus (HBV)in Jiangsu Province, China Methods: The incidence rates of HBV in Jiangsu province from 2004 to 2014 were obtained from the National Notifiable Disease Reporting System (NNDRS). A stratified cluster random sampling method was used to select 3,002 participants aged 1–29 years across 13 HBV monitoring points throughout the province, which had been classified as either urban or rural. HBV serological markers were measured by Abbott microparticle enzyme immunoassay (MEIA) kits (Abbott Laboratories, Chicago, Illinois). Results: The incidence of hepatitis B decreased by approximately 71.44% in Jiangsu province between 2004 and 2014. Serological assessments showed that the prevalence of the HBsAg, anti-HBc, and anti-HBsin the 1–29 age group were 1.20%, 5.33%,and 66.89%, respectively. There was a significantly lower prevalence of HepB who were vaccinated than in unvaccinated subjects (0.46% vs 14.93%, p < .0001). Among these the ages of 1–29, the coverage rate drops from 97.7% to 56.6% with age,andthe timely rate among people aged 1–14 years was 90.93%. Conclusions: Since the HepB was integrated into the immunization programme in Jiangsu province,the rate of hepatitis B reported and the prevalence of HBsAg decreased significantly, and the coverage of HepB and the vaccination rate within 24 hours after birth have played an important role in reducing HBV infection

    The Microtubule End Binding Protein Mal3 Is Essential for the Dynamic Assembly of Microtubules during <i>Magnaporthe oryzae</i> Growth and Pathogenesis

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    Cytoskeletal microtubules (MTs) play crucial roles in many aspects of life processes in eukaryotic organisms. They dynamically assemble physiologically important MT arrays under different cell conditions. Currently, aspects of MT assembly underlying the development and pathogenesis of the model plant pathogenic fungus Magnaporthe oryzae (M. oryzae) are unclear. In this study, we characterized the MT plus end binding protein MoMal3 in M. oryzae. We found that knockout of MoMal3 results in defects in hyphal polar growth, appressorium-mediated host penetration and nucleus division. Using high-resolution live-cell imaging, we further found that the MoMal3 mutant assembled a rigid MT in parallel with the MT during hyphal polar growth, the cage-like network in the appressorium and the stick-like spindle in nuclear division. These aberrant MT organization patterns in the MoMal3 mutant impaired actin-based cell growth and host infection. Taken together, these findings showed that M. oryzae relies on MoMal3 to assemble elaborate MT arrays for growth and infection. The results also revealed the assembly mode of MTs in M. oryzae, indicating that MTs are pivotal for M. oryzae growth and host infection and may be new targets for devastating fungus control

    Chemical determination from samples of Sihetun in the western Liaoning Province, northeastern China

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    Geochemical analysis of the 14.4-m-thick lacustrine succession of the Lower Cretaceous Yixian Formation (Jehol Group) has yielded new insights concerning vertebrate mass mortality events in the Lake Sihetun volcanic caldera in western Liaoning Province (northeastern China) that produced the Jehol Biota fossil lagerstätten. The long-term evolution of the caldera system resulted in a shift from felsic to mafic magma chemistry, accompanied by a reduced frequency of pyroclastic eruptions, declining hydrothermal activity, and lower lacustrine productivity. The basal Tetrapod Beds exhibit strong hydrothermal influence, as indicated by enrichments of boron (B), certain alkalis (Rb, Cs), rare-earth elements (REEs), yttrium (Y), and many metals (e.g., Co, Cr, Cu, Ge, Mo, Ni, Sb, U, V, and W), and by strongly negative molybdenum isotope compositions (d98Mo to -2.50 per mil) that may record large fractionations between molybdate and thiomolybdate species in the Sihetun caldera hydrothermal system. In contrast, the overlying Fish Beds and Non-Fossiliferous Beds have an elemental and Mo-isotopic composition similar to calc-alkaline basalts (d98Mo = -0.29 ± 0.04 per mil) in the surrounding watershed, suggesting weathering of Yixian Formation volcanic rocks as the major source of sediment. During its < 700-kyr-long history, Lake Sihetun was affected by four environmental cycles, each commencing with a series of pyroclastic eruptions that triggered systematic changes in lakewater chemistry. Following each eruption interval, enhanced weathering of volcanic ash in the surrounding watershed caused lakewater pH to decrease and lacustrine productivity to increase. Continued weathering of bases from basement volcanic rocks subsequently produced alkaline conditions in the lake, leading to precipitation of authigenic carbonate layers and lower lacustrine productivity. Analysis of geochemical redox proxies strongly suggests that the Lake Sihetun water column was completely oxic, in contrast to earlier inferences of a stratified anoxic water column, and that ubiquitous lamination in the lacustrine succession was due to other factors such as widespread microbial mats and/or rapid sediment deposition
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