14,728 research outputs found

    Developing a teaching chatbot for learning tools and equipment in technology classrooms

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    Using and applying tools and equipment for designing and building projects has always been indispensable in living technology classrooms. However, students must be aware of their proper use to avoid mistakes and safety concerns. In recent years, chatbots have been widely used in various fields, offering instant, interactive responses, and their application in educational contexts has also increased rapidly. Therefore, this study developed a chatbot for LINE, a popular messaging app in Asia, for teaching standard hand tools and equipment in living technology classrooms at secondary schools. This chatbot covered (1) measuring tools, (2) hand tools, (3) power tools and equipment, and others. A total of 49 tools and pieces of equipment were included. The instructional content for each consisted of (1) instructions, (2) operating procedures and skills, and (3) troubleshooting and maintenance. The user interface adopted point-and-click forms and graphical menus to quickly guide users searching for specific information. In addition, users can enter relevant keywords and the chatbot will answer the corresponding content. The chatbot is expected to solve student questions more efficiently and assist teachers, improving the effectiveness and convenience of these hands-on lessons

    A Photonic Crystal Slab Laplace Differentiator

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    We introduce an implementation of a Laplace differentiator based on a photonic crystal slab that operates at transmission mode. We show that the Laplace differentiator can be implemented provided that the guided resonances near the Γ\Gamma point exhibit an isotropic band structure. Such a device may facilitate nanophotonics-based optical analog computing for image processing.Comment: Primary text 6 pages, 5 figures; Supplementary material 5 pages, 3 figure

    Biological Lasers for Biomedical Applications

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    A biolaser utilizes biological materials as part of its gain medium and/or part of its cavity. It can also be a micro- or nanosized laser embedded/integrated within biological materials. The biolaser employs lasing emission rather than regular fluorescence as the sensing signal and therefore has a number of unique advantages that can be explored for broad applications in biosensing, labeling, tracking, contrast agent development, and bioimaging. This article reports on the progress in biolasers with focus on the work done in the past five years. In the end, the possible future directions of the biolaser are discussed.Biolasers and their applications in biology and biomedicine are reviewed in this progress report. The biolaser employs lasing emission rather than regular fluorescence as the sensing signal and therefore has a number of unique advantages that can be explored for broad applications in biosensing, labeling, tracking, contrast agent development, and bioimaging.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151258/1/adom201900377.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151258/2/adom201900377_am.pd

    Internal shock model for the X-ray flares of Swift J1644+57

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    Swift J1644+57 is an unusual transient event, likely powered by the tidal disruption of a star by a massive black hole. There are multiple short timescales X-ray flares were seen over a span of several days. We propose that these flares could be produced by internal shocks. In the internal shock model, the forward and reverse shocks are produced by collisions between relativistic shells ejected from central engine. The synchrotron emission from the forward and reverse shocks could dominate at two quite different energy bands under some conditions, the relativistic reverse shock dominates the X-ray emission and the Newtonian forward shock dominates the infrared and optical emission. We show that the spectral energy distribution of Swift J1644+57 could be explained by internal shock model.Comment: 6 pages, 3 figures, accepted for publication in MNRA

    Chromatin Laser Imaging Reveals Abnormal Nuclear Changes for Early Cancer Detection

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    We developed and applied rapid scanning laser-emission microscopy to detect abnormal changes in cell nuclei for early diagnosis of cancer and cancer precursors. Regulation of chromatins is essential for genetic development and normal cell functions, while abnormal nuclear changes may lead to many diseases, in particular, cancer. The capability to detect abnormal changes in apparently normal tissues at a stage earlier than tumor development is critical for cancer prevention. Here we report using LEM to analyze colonic tissues from mice at-risk for colon cancer by detecting prepolyp nuclear abnormality. By imaging the lasing emissions from chromatins, we discovered that, despite the absence of observable lesions, polyps, or tumors under stereoscope, high-fat mice exhibited significantly lower lasing thresholds than low-fat mice. The low lasing threshold is, in fact, very similar to that of adenomas and is caused by abnormal cell proliferation and chromatin deregulation that can potentially lead to cancer. Our findings suggest that conventional methods, such as colonoscopy, may be insufficient to reveal hidden or early tumors under development. We envision that this work will provide new insights into LEM for early tumor detection in clinical diagnosis and fundamental biological and biomedical research of chromatin changes at the biomolecular level of cancer development
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