All-polymer monolithic resonant integrated optical gyroscope.

Resonant integrated optical gyroscopes (RIOGs) can integrate discrete optical components as a promising candidate for high-performance micro-optical gyroscopes. However, the current RIOG still consists of discrete elements due to the difficulty and complexity of heterogeneous integration of resonator and modulators. This paper presents on-chip integration of optical functional components including modulator, resonator, beam splitter, and coupler for the organic-polymer-based RIOG. Simple integrated optical processes such as spin coating, lithography, and etching can realize RIOG chips with low cost, size, weight, and power (CSWaP) features. Thereinto, the electro-optic modulator (EOM) fabricated by self-synthesized electro-optic (EO) polymer (side chain bonded polyurethane imide) exhibits less than 2 V half-wave voltage, which is half of the lithium niobate (LiNbO3) modulator. With respect to the resonator, a quality factor of approximately million was achieved using low-loss fluorinated polymer. In addition, the angular velocity sensing of RIOG was also investigated. By demonstrating the monolithic integration of the resonator and modulators, such an all-polymer RIOG chip prototype builds the technical foundation for the precision fully integrated optical gyroscope.

Nanoscale Valley Modulation by Surface Plasmon Interference.

Excitons in two-dimensional (2D) materials have attracted the attention of the community to develop improved photoelectronic devices. Previous reports are based on direct excitation where the out-of-plane illumination projects a uniform single-mode light spot. However, because of the optical diffraction limit, the minimal spot size is a few micrometers, inhibiting the precise manipulation and control of excitons at the nanoscale level. Herein, we introduced the in-plane coherent surface plasmonic interference (SPI) field to excite and modulate excitons remotely. Compared to the out-of-plane light, a uniform in-plane SPI suggests a more compact spatial volume and an abundance of mode selections for a single or an array of device modulation. Our results not only build up a fundamental platform for operating and encoding the exciton states at the nanoscale level but also provide a new avenue toward all-optical integrated valleytronic chips for future quantum computation and information applications.

Effectiveness of high frequency ultrasound on pressure ulcer: A systematic review protocol of randomized controlled trial.

BACKGROUND: This study aims to systematically assess the effectiveness of high frequency ultrasound (HFUS) on pressure ulcer (PU). METHODS: In this study, PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure will be searched from inception to the present without any language limitations. The primary outcomes include change in ulcer area, and time complete healing. The secondary outcomes consist of proportion of ulcers healed within trial period, quality of life, pain intensity, and adverse events. Cochrane risk of bias tool will be used to assess methodological quality. RevMan 5.3 software (London, UK) will be used to analyze the data. RESULTS: This study will analyze change in ulcer area, time complete healing, proportion of ulcers healed within study period, quality of life, pain intensity, and adverse events on HFUS in patients with PU. CONCLUSION: This study will provide most recent evidence for the effectiveness and safety of HFUS for patients with PU. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019138177.

Flexible Thermo-Optic Variable Attenuator based on Long-Range Surface Plasmon-Polariton Waveguides.

A flexible thermo-optic variable attenuator based on long-range surface plasmon-polariton (LRSPP) waveguide for microwave photonic application was investigated. Low-loss polymer materials and high-quality silver strip were served as cladding layers and core layer of the LRSPP waveguide, respectively. By using finite element method (FEM), the thermal distribution and the optical field distribution have been carefully optimized. The fabricated device was characterized by end-fire excitation with a 1550 nm laser. The transmission performance of high-speed data and microwave modulated optical signal was measured while using a broadband microwave photonics link. The results indicated that the propagation loss of the LRSPP waveguide was about 1.92 dB/cm. The maximum attenuation of optical signal was about 28 dB at a driving voltage of 4.17 V, and the variable attenuation of microwave signals was obviously observed by applying different driving voltage to the heater. This flexible plasmonic variable attenuator is promising for chip-scale interconnection in high-density photonic integrated circuits and data transmission and amplitude control in microwave photonic systems.

Seeds screening aqueous synthesis, multiphase interfacial separation and in situ optical characterization of invisible ultrathin silver nanowires.

We report a multi-step synthetic method to obtain ultrathin silver nanowires (Ag NWs) from an aqueous solution with a ∼17 nm diameter average, and where some of them decreased down to 9 nm. Carefully designed seed screening processes including LED irradiation at high temperature for a short time, and then continuous H2O2 etching, and relative growth mechanisms of high-yield five-twinned pentagonal seeds and ultrathin Ag NWs in aqueous environment are detailed. Then, a rapid and simple multiphase interfacial assembly method particularly suitable for the separation of ultrathin Ag NWs from various by-products was demonstrated with a clear mechanism explanation. Next, a unique optical interaction between light and individual AG NWs, as well as feature structures in the AG NWs film, was investigated by a micro-domain optical confocal microscope measurement in situ together with a theoretical explanation using modal transmission theory. That revealed that the haze problem of AG NWs films was not only arising from the interaction between light and individual or crossed Ag NWs but was also greatly dependent on a weak coupling effect of leaky modes supported by adjacent Ag NWs with large distances which had not been considered before. We then provided direct experimental evidence and concluded how to obtain haze-free films with 100% transparency in the whole visible range based on ultrathin Ag NWs. This breakthrough in diameter confinement and purification of Ag NWs is a highly expected step to overcome the well-focused light diffusion and absorption problems of Ag NWs-based devices applied in various fields such as flexible electronics, high-clarity displays, visible transparent heaters, photovoltaics and various optoelectronic technologies.

Ibandronate for prevention and treatment of glucocorticoid-induced osteoporosis in rabbits.

The objective of this study is to evaluate the efficacy of ibandronate (IBN) in prevention and treatment of glucocorticoid-induced osteoporosis in rabbits. A total of 60 New Zealand white rabbits were randomly allocated into six groups. Twenty rabbits in the control group were injected with saline. Forty rabbits received dexamethasone (DX) treatment at a dose of 3 mg/kg twice weekly during the first 6 weeks, while 10 of these rabbits (group IBN&DX) were injected additionally with IBN at a dose of 2 mg/kg before DX treatment. At week 6, the rabbits from IBN&DX group, 10 rabbits from control group (group CNTR-1) and 10 rabbits treated with DX (group DX6) were killed. Half (10) of the remaining rabbits in DX group were continued for DX treatment at a dose of 3 mg/kg once weekly (group DX12), while the other half (10) rabbits (group DX&IBN) additionally received IBN injection (2 mg/kg) once before continuing DX treatment. The remaining rabbits (10) in an additional of control group (group CNTR-2) continuously received saline. At week 12, all rabbits were killed for bone biomechanical analysis and histological examination. At week 6, the analysis of bone biomechanical and histological results of group CNTR-1 and DX6 showed that GIOP rabbit models were successfully established. Compared with group DX6, bone volume/tissue volume (BV/TV), trabecular number (Tb.N) and trabecular thickness (Tb.Th) of lumbar spine in group IBN&DX were increased by 100, 45.74 and 40.55%, respectively (P < 0.01). Meanwhile, BV/TV and Tb.N of femoral neck were increased by 30.29 and 16.86%, respectively (P < 0.01). The maximum compressive load, the maximum bending stress and the maximum torque were increased by 24.19, 29.91 and 37.24%, respectively (P < 0.01). At week 12, in comparison of the results between group DX12 and group DX6, the histomorphometric and mechanical analysis demonstrated that prolonged DX treatment could lead to further loss of bone mass and strength. Compared with group DX12, BV/TV, Tb.N and Tb.Th of lumbar spine in group DX&IBN were increased by 73.34, 39.02 and 23.87%, respectively (P < 0.05), the parameters of femoral neck were increased by 88.75, 31.29 and 42.01%, respectively (P < 0.01), and the biomechanical parameters were increased by 54.36, 21.38 and 105.75%, respectively (P < 0.05). IBN could effectively prevent and treat high-dosing glucocorticoid-induced loss of bone mass and strength in rabbits.