Abstract:We demonstrate the formation of micropatterned sol-gel structures containing active proteins by patterning with polydimethylsiloxane (PDMS) microchannels. To transport sol solution efficiently into the hydrophobic PDMS microchannels, a hydrophilic-hydrophobic block copolymer was used to impart hydrophilicity to the PDMS microchannels. Poor adhesion of the micropatterned gel structure onto glass slides was improved by treating the glass surface with a polymeric substrate. To minimize cracks in the gel microstructure, hybrid matrices of interpenetrating organic and inorganic networks were prepared containing the reactive organic moieties polyvinylalcohol or polyvinylpyrrolidone. Retention of biochemical activity within the micropatterned gel was demonstrated by performing immunobinding assays with immobilized immunoglobulin G (IgG) antibody. The potential application of microfluidics technology to immobilized-enzyme biocatalysis was demonstrated using PDMS-patterned microchannels filled with trypsin-containing sol-gels. This work provides a foundation for the microfabrication of functional protein chips using sol-gel processes.
In order to test the existence of the sterile neutrino, NEOS experiment was performed from August 2015 to May 2016. The prompt energy spectrum from the inverse beta decay of electron antineutrino from a 2.8 GW th reactor was measured at 24 m distance. The number of measured IBD candidates is about 2000 per day during reactor-on period and a ratio of signal to background is about 22. The result shows no strong evidence of active-to-sterile neutrino. An exclusion-limit curve for 3+1 hypothesis is found at 90% CL. via shape-only analysis.
We propose a new method for high-speed, three-dimensional (3-D) fluorescence imaging, which we refer to as dual-detection confocal fluorescence microscopy (DDCFM). In contrast to conventional beam-scanning confocal fluorescence microscopy, where the focal spot must be scanned either optically or mechanically over a sample volume to reconstruct a 3-D image, DDCFM can obtain the depth of a fluorescent emitter without depth scanning. DDCFM comprises two photodetectors, each with a pinhole of different size, in the confocal detection system. Axial information on fluorescent emitters can be measured by the axial response curve through the ratio of intensity signals. DDCFM can rapidly acquire a 3-D fluorescent image from a single two-dimensional scan with less phototoxicity and photobleaching than confocal fluorescence microscopy because no mechanical depth scans are needed. We demonstrated the feasibility of the proposed method by phantom studies.
We propose dual-detection confocal reflectance microscopy (DDCRM) for high-speed 3D surface profiling. In comparison with conventional confocal microscopy, DDCRM can realize surface profiling without axial scanning. DDCRM is composed of two point detectors, each with a pinhole of different size. The ratio of the axial response curves measured by the two detectors provides the relationship between the axial position of the sample and the ratio of the intensity signals. Furthermore, DDCRM has a normalizing effect which allows this method to accurately measure the height of samples with various reflectance characteristics.
Recently, the number of tunnels is increasing due to urbanization, and fire accidents in tunnels are likewise increasing. In particular, in a long tunnel of more than 1 km it is very difficult to track the exact location of a fire, accident vehicles, and the fire brigade, as well as whether a fire occurred. In this paper, we analyze various types of accidents that may occur in tunnel fires and propose detection, search, and rescue techniques to cope with them. For early detection of accidents, we propose various sensors using Internet of Things (IoT) technology and sensor networks to connect them. These sensors can detect not only a fire but also the position of the vehicle in which the fire is occurring in real time. We also propose a robotic system and operation technique that can be controlled by a fire fighter for more precise search operation. For rescue procedures, localization and tracking technology for fire fighters and robots is proposed. Finally, the efficiency of the proposed system was verified through actual performance tests, including simulations of actual placement and operation in tunnels. Through the construction of the equipment in an actual tunnel 1.9 km long, we show that the proposed system is good enough to cope with fire accidents, in terms of the delivery ratio of the collected data, fire recognition ratio, localization accuracy, and response delay.
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