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In this study, all‐optical organic–inorganic hybrid waveguide switches are proposed based on the photothermal effect of Au‐MOF composites. The embedded waveguide structure is directly defined using SiO2 grooves on a silicon substrate. Self‐synthesized Au‐MOF/PMMA and SiO2‐TiO2 network grafting PMMA are used as the core and cladding materials, respectively. The organic–inorganic hybrid shielding layer is formed using an oxygen ion etching process to avoid corrosion from the cladding solvent. A directional coupling switching structure is designed and fabricated. The switching time of the all‐optical device is 500 µs, the photothermal tuning sensitivity is 19.10 nm mW−1, the driving optical power consumption is 0.67 mW, and the extinction ratio is close to 9.83 dB. This technique is desirable for photothermal control of light in an all‐optical signal‐processing network. [ABSTRACT FROM AUTHOR]

Neuronal hyperactivity induced by β‐amyloid (Aβ) is an early pathological feature in Alzheimer's disease (AD) and contributes to cognitive decline in AD progression. However, the underlying mechanisms are still unclear. Here, we revealed that Aβ increased the expression level of synaptic adhesion molecule protocadherin‐γC5 (Pcdh‐γC5) in a Ca2+‐dependent manner, associated with aberrant elevation of synapses in both Aβ‐treated neurons in vitro and the cortex of APP/PS1 mice in vivo. By using Pcdhgc5 gene knockout mice, we demonstrated the critical function of Pcdh‐γC5 in regulating neuronal synapse formation, synaptic transmission, and cognition. To further investigate the role of Pcdh‐γC5 in AD pathogenesis, the aberrantly enhanced expression of Pcdh‐γC5 in the brain of APP/PS1 mice was knocked down by shRNA. Downregulation of Pcdh‐γC5 efficiently rescued neuronal hyperactivity and impaired cognition in APP/PS1 mice. Our findings revealed the pathophysiological role of Pcdh‐γC5 in mediating Aβ‐induced neuronal hyperactivity and cognitive deficits in AD and identified a novel mechanism underlying AD pathogenesis. [ABSTRACT FROM AUTHOR]

An optical measurement method, the fold-ray videometrics method, that is applicable to the deformation measurement of large structures is proposed. Through an illustration of ship deformation, the principle of fold-ray videometrics and the composition of the deformation measurement system are introduced. The fold-ray videometrics method is able to transfer or relay three-dimensional geometric information with a fold-ray optical path and thus is capable of real-time measurement of three-dimensional positions, attitudes, and deformations between nonintervisible objects and those of intervisible objects with a very large angle of view. The proposed method therefore has the potential to be applied in deformation measurement of large structures. OCIS codes: 110.3925, 120.4820.

Fringe patterns generated by electronic speckle-pattern interferometry are full of high-spatial-frequency and high-contrast speckle noise. Filtering with contoured windows has proved to be an efficient approach to filtering out speckle noise while retaining the fringe patterns. Furthermore, with contoured windows the contoured correlation fringe pattern method can be used to derive smooth, normalized, consistent fringes. Contoured windows previously were determined by fringe orientation only, and this process generated accumulated errors. We propose two new algorithms with which to obtain the contoured windows according to the fringe intensity slope and the distance ratio to neighboring skeletons. These new techniques can determine contoured windows more precisely. OCIS code: 120.6160.

Filtering off noise from fringe patterns is important for the processing and analysis of interferometric fringe patterns. Spin filters proposed by the author have been proven to be effective in filtering off noise without blurring and distortion to fringe patterns with small fringe curvature. But spin filters still have problems processing fringe patterns with large fringe curvature. We develop a new spin filtering with curve windows that is suitable for all kinds of fringe pattern regardless of fringe curvature. The experimental results show that the new spin filtering provides optimal results in filtering off noise without distortion of the fringe features, regardless of fringe curvature. OCIS codes: 100.080, 100.160, 100.060, 350.060.

Generalized spin filters, including several directional filters such as the directional median filter and the directional binary filter, are proposed for removal of the noise of fringe patterns and the extraction of fringe skeletons with the help of fringe-orientation maps (FOM's). The generalized spin filters can filter off noise on fringe patterns and binary fringe patterns efficiently, without distortion of fringe features. A quadrantal angle filter is developed to filter off the FOM. With these new filters, the derivative-sign binary image (DSBI) method for extraction of fringe skeletons is improved considerably. The improved DSBI method can extract high-density skeletons as well as common density skeletons.