191 research outputs found

    Virus-host interactions: new insights from the small RNA world

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    RNA silencing has a known role in the antiviral responses of plants and insects. Recent evidence, including the finding that the Tat protein of human immunodeficiency virus (HIV) can suppress the host's RNA-silencing pathway and may thus counteract host antiviral RNAs, suggests that RNA-silencing pathways could also have key roles in mammalian virus-host interactions

    HiTIN: Hierarchy-aware Tree Isomorphism Network for Hierarchical Text Classification

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    Hierarchical text classification (HTC) is a challenging subtask of multi-label classification as the labels form a complex hierarchical structure. Existing dual-encoder methods in HTC achieve weak performance gains with huge memory overheads and their structure encoders heavily rely on domain knowledge. Under such observation, we tend to investigate the feasibility of a memory-friendly model with strong generalization capability that could boost the performance of HTC without prior statistics or label semantics. In this paper, we propose Hierarchy-aware Tree Isomorphism Network (HiTIN) to enhance the text representations with only syntactic information of the label hierarchy. Specifically, we convert the label hierarchy into an unweighted tree structure, termed coding tree, with the guidance of structural entropy. Then we design a structure encoder to incorporate hierarchy-aware information in the coding tree into text representations. Besides the text encoder, HiTIN only contains a few multi-layer perceptions and linear transformations, which greatly saves memory. We conduct experiments on three commonly used datasets and the results demonstrate that HiTIN could achieve better test performance and less memory consumption than state-of-the-art (SOTA) methods.Comment: Accepted by ACL'2

    Eliminating micro-porous layer from gas diffusion electrode for use in high temperature polymer electrolyte membrane fuel cell

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    © 2016 Elsevier B.V. In this work, we report a simple strategy to improve the performance of high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) by eliminating the micro-porous layer (MPL) from its gas diffusion electrodes (GDEs). Due to the absence of liquid water and the general use of high amount of catalyst, the MPL in a HT-PEMFC system works limitedly. Contrarily, the elimination of the MPL leads to an interlaced micropore/macropore composited structure in the catalyst layer (CL), which favors gas transport and catalyst utilization, resulting in a greatly improved single cell performance. At the normal working voltage (0.6 V), the current density of the GDE eliminated MPL reaches 0.29 A cm−2, and a maximum power density of 0.54 W cm−2 at 0.36 V is obtained, which are comparable to the best results yet reported for the HT-PEMFCs with similar Pt loading and operated using air. Furthermore, the MPL-free GDE maintains an excellent durability during a preliminary 1400 h HT-PEMFC operation, owing to its structure advantages, indicating the feasibility of this electrode for practical applications

    Eliminating micro-porous layer from gas diffusion electrode for use in high temperature polymer electrolyte membrane fuel cell

    Get PDF
    In this work, we report a simple strategy to improve the performance of high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) by eliminating the micro-porous layer (MPL) from its gas diffusion electrodes (GDEs). Due to the absence of liquid water and the general use of high amount of catalyst, the MPL in a HT-PEMFC system works limitedly. Contrarily, the elimination of the MPL leads to an interlaced micropore/macropore composited structure in the catalyst layer (CL), which favors gas transport and catalyst utilization, resulting in a greatly improved single cell performance. At the normal working voltage (0.6 V), the current density of the GDE eliminated MPL reaches 0.29 A cm2 , and a maximum power density of 0.54 W cm2 at 0.36 V is obtained, which are comparable to the best results yet reported for the HT-PEMFCs with similar Pt loading and operated using air. Furthermore, the MPLfree GDE maintains an excellent durability during a preliminary 1400 h HT-PEMFC operation, owing to its structure advantages, indicating the feasibility of this electrode for practical applications

    Emission characteristics of laser-induced plasma using collinear long and short dual-pulse LIBS

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    The collinear long and short dual-pulse LIBS (DP-LIBS) was employed to clarify the emission characteristics from laser-induced plasma. The plasma was sustained and became stable by the long pulse-width laser with the pulse width of 60 μs under FR (free running) condition as an external energy source. Comparing the measurement results of stainless steel in air using SP-LIBS and DP-LIBS, the emission intensity was enhanced using DP-LIBS markedly. The temperature of plasma induced by DP-LIBS was maintained at higher temperature under different gate delay time and short pulse-width laser power conditions compared with these measured using SP-LIBS of short pulse width. Moreover, the variation rates of plasma temperature measured using DP-LIBS were also lower. The superior detection ability was verified by the measurement of aluminum sample in water. The spectra were clearly detected using DP-LIBS, whereas it cannot be identified using SP-LIBS of short pulse width and long pulse width. The effects of gate delay time and short pulse-width laser power were also discussed. These results demonstrate the feasibility and enhanced detection ability of the proposed collinear long and short DP-LIBS method
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