16,012 research outputs found
Developing a teaching chatbot for learning tools and equipment in technology classrooms
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
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 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
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
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
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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