496 research outputs found

    Dynamic Generation and Editing System for Wrongly Written Chinese Characters Font

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    The uniqueness of Chinese makes Chinese language a hotspot in language learning. In view of the problem of wrongly written character teaching in Chinese language teaching, it provides a simple, convenient, and efficient input method of wrongly written characters and realizes a dynamic generation and editing system for wrongly written Chinese character font, which solves the problems of real-time edit, coding, and input of wrongly written character in editing process using dynamic editing technology, and provides a convenient input method of wrongly written character in editing, printing, typesetting, and the research of digital Chinese language teaching. This method can also be used in dynamic editing, generation and processing of ancient variants, Oracle bone inscriptions, Bronze inscription, folk combined characters, and other fonts

    Calculation of Sentence Semantic Similarity Based on Syntactic Structure

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    Combined with the problem of single direction of the solution of the existing sentence similarity algorithms, an algorithm for sentence semantic similarity based on syntactic structure was proposed. Firstly, analyze the sentence constituent, then through analysis convert sentence similarity into words similarity on the basis of syntactic structure, then convert words similarity into concept similarity through words disambiguation, and, finally, realize the semantic similarity comparison. It also gives the comparison rules in more detail for the modifier words in the sentence which also have certain contributions to the sentence. Under the same test condition, the experiments show that the proposed algorithm is more intuitive understanding of people and has higher accuracy

    LIVE, ATTENUATED VACCINES AND METHODS OF MAKING AND USING

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    A live, attenuated HIV vaccine is provided, and methods of making a atenuated HIV vaccine are provided

    A Novel Route for Preparation of Hollow Carbon Nanospheres Without Introducing Template

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    A newly developed route for the synthesis of hollow carbon nanospheres without introducing template under hydrothermal conditions was reported. Hollow carbon nanospheres with the diameter of about 100 nm were synthesized using alginate as reagent only. Many instruments were applied to characterize the morphologies and structures of carbon hollow nanospheres, such as XRD, TEM, and Raman spectroscopy. The possible formation and growth mechanism of carbon hollow spheres were discussed on the basis of the investigation of reaction influence factors, such as temperature, time, and content. The findings would be useful for the synthesis of more materials with hollow structure and for the potential use in many aspects. The loading of SnO2on the surface of carbon hollow spheres was processed, and its PL property was also characterized

    A Coaxially Integrated Photonic Orbital Angular Momentum Beam Multiplexer

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    We demonstrate an integrated photonic orbital angular momentum beam multiplexer consisting of four nested arc waveguide gratings. Well-defined OAM mode emissions over wide bandwidth of 1-nm enables simultaneous wavelength division multiplexing and OAM multiplexing

    SIVcpz closely related to the ancestral HIV-1 is less or non-pathogenic to humans in a hu-BLT mouse model

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    The HIV-1 pandemic is a consequence of the cross-species transmission of simian immunodeficiency virus in wild chimpanzees (SIVcpz) to humans. Our previous study demonstrated SIVcpz strains that are closely related to the ancestral viruses of HIV-1 groups M (SIVcpzMB897) and N (SIVcpzEK505) and two SIVcpz lineages that are not associated with any known HIV-1 infections in humans (SIVcpzMT145 and SIVcpzBF1167), all can readily infect and robustly replicate in the humanized-BLT mouse model of humans. However, the comparative pathogenicity of different SIVcpz strains remains unknown. Herein, we compared the pathogenicity of the above four SIVcpz strains with HIV-1 using humanized-BLT mice. Unexpectedly, we found that all four SIVcpz strains were significantly less pathogenic or non-pathogenic compared to HIV-1, manifesting lower degrees of CD4+ T-cell depletion and immune activation. Transcriptome analyses of CD4+ T cells from hu-BLT mice infected with SIVcpz versus HIV-1 revealed enhanced expression of genes related to cell survival and reduced inflammation/immune activation in SIVcpz-infected mice. Together, our study results demonstrate for the first time that SIVcpz is significantly less or non-pathogenic to human immune cells compared to HIV-1. Our findings lay the groundwork for a possible new understanding of the evolutionary origins of HIV-1, where the initial SIVcpz crossspecies transmission virus may be initially less pathogenic to humans

    Distinct transcriptome profiles of Gag-specific CD8+ T cells temporally correlated with the protection elicited by SIVΔnef live attenuated vaccine

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    The live attenuated vaccine (LAV) SIVmac239Δnef (SIVΔnef) confers the best protection among all the vaccine modalities tested in rhesus macaque model of HIV-1 infection. This vaccine has a unique feature of time-dependent protection: macaques are not protected at 3±5 weeks post vaccination (WPV), whereas immune protection emerges between 15 and 20 WPV. Although the exact mechanisms of the time-dependent protection remain incompletely understood, studies suggested that both cellular and humoral immunities contribute to this time-dependent protection. To further elucidate the mechanisms of protection induced by SIVΔnef, we longitudinally compared the global gene expression profiles of SIV Gag-CM9+ CD8+ (Gag-specific CD8+) T cells from peripheral blood of Mamu-A*01+ rhesus macaques at 3 and 20 WPV using rhesus microarray. We found that gene expression profiles of Gag-specific CD8+ T cells at 20 WPV are qualitatively different from those at 3 WPV. At 20 WPV, the most significant transcriptional changes of Gag-specific CD8+ T cells were genes involved in TCR signaling, differentiation and maturation toward central memory cells, with increased expression of CCR7, TCRα, TCRβ, CD28 and decreased expression of CTLA-4, IFN-γ, RANTES, granzyme A and B. Our study suggests that a higher quality of SIV-specific CD8+ T cells elicited by SIVΔnef over time contributes to the maturation of time-dependent protection

    A strategy of gene overexpression based on tandem repetitive promoters in Escherichia coli

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    <p>Abstract</p> <p>Background</p> <p>For metabolic engineering, many rate-limiting steps may exist in the pathways of accumulating the target metabolites. Increasing copy number of the desired genes in these pathways is a general method to solve the problem, for example, the employment of the multi-copy plasmid-based expression system. However, this method may bring genetic instability, structural instability and metabolic burden to the host, while integrating of the desired gene into the chromosome may cause inadequate transcription or expression. In this study, we developed a strategy for obtaining gene overexpression by engineering promoter clusters consisted of multiple core-<it>tac-</it>promoters (MCP<it>tac</it>s) in tandem.</p> <p>Results</p> <p>Through a uniquely designed <it>in vitro </it>assembling process, a series of promoter clusters were constructed. The transcription strength of these promoter clusters showed a stepwise enhancement with the increase of tandem repeats number until it reached the critical value of five. Application of the MCP<it>tac</it>s promoter clusters in polyhydroxybutyrate (PHB) production proved that it was efficient. Integration of the <it>phaCAB </it>genes with the 5CP<it>tac</it>s promoter cluster resulted in an engineered <it>E.coli </it>that can accumulate 23.7% PHB of the cell dry weight in batch cultivation.</p> <p>Conclusions</p> <p>The transcription strength of the MCP<it>tac</it>s promoter cluster can be greatly improved by increasing the tandem repeats number of the core-<it>tac</it>-promoter. By integrating the desired gene together with the MCP<it>tac</it>s promoter cluster into the chromosome of <it>E. coli</it>, we can achieve high and stale overexpression with only a small size. This strategy has an application potential in many fields and can be extended to other bacteria.</p

    Assessing the liquefaction potential of seabed soils based on ocean ambient noise in the Yellow River Delta

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    Seabed soils can undergo liquefaction under cyclic loading, resulting in a rapid decrease in strength and stiffness, which may lead to the destruction of offshore structures. Therefore, the assessment of seabed soil liquefaction will become an important factor in disaster prevention and risk analysis in coastal and offshore engineering construction. In this study, the ocean ambient noise with low-frequency, long-wavelength, and wide-band characteristics was used to conduct and analysis noise based on the horizontal-to-vertical spectral ratio method. The shear wave velocity of the seabed soil was obtained by inverting the ocean ambient noise dataset. Then, we proposed a shear wave velocity threshold that can be used for liquefaction assessment of Holocene unconsolidated fine-grained soils by statistical analysis, and the liquefaction potential of the soils was evaluated according to 1-D shear wave velocity structures and 2-D shear wave velocity profiles. The results showed that the distribution of the shear wave velocity obtained by inverting ocean ambient noise was generally consistent with the measured shear wave velocity in the field, indicating that the inversion results have a certain degree of accuracy. A shear wave velocity threshold of 200 m/s was proposed for liquefaction assessment, determining that the soils within 0-10 m depth in the coastal area of Yellow River Delta have liquefaction potential. This result is in accordance with the assessment based on the critical shear wave velocity, indicating that this threshold is applicable to the assessment of seabed soil liquefaction in the Yellow River Delta. The in-situ observations of ocean ambient noise provide a more convenient, economical, and environmentally friendly method, which can help to investigate marine geology disasters and serve marine engineering construction
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