In-band full-duplex(IBFD) technology can double the spectrum utilization efficiency for wireless communications,and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-inte...In-band full-duplex(IBFD) technology can double the spectrum utilization efficiency for wireless communications,and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-interference is the major challenge for the application of IBFD technology, which must be resolved. Compared with the conventional electronic method, the photonic self-interference cancellation(PSIC) technique has the advantages of wide bandwidth, high amplitude and time delay tuning precision, and immunity to electromagnetic interference.Integrating the PSIC system on chip can effectively reduce the size, weight, and power consumption and meet the application requirement, especially for mobile terminals and small satellite payloads. In this paper, the silicon integrated PSIC chip is presented first and demonstrated for IBFD communication. The integrated PSIC chip comprises function units including phase modulation, time delay and amplitude tuning, sideband filtering, and photodetection, which complete the matching conditions for RF self-interference cancellation. Over the wide frequency range of C, X, Ku, and K bands, from 5 GHz to 25 GHz, a cancellation depth of more than 20 dB is achieved with the narrowest bandwidth of 140 MHz. A maximum bandwidth of 630 MHz is obtained at a center frequency of10 GHz. The full-duplex communication experiment at Ku-band by using the PSIC chip is carried out. Cancellation depths of 24.9 dB and 26.6 dB are measured for a bandwidth of 100 MHz at central frequencies of 12.4 GHz and14.2 GHz, respectively, and the signal of interest(SOI) with 16-quadrature amplitude modulation is recovered successfully. The factors affecting the cancellation depth and maximum interference to the SOI ratio are investigated in detail. The performances of the integrated PSIC system including link gain, noise figure, receiving sensitivity, and spurious free dynamic range are characterized.展开更多
Imbalance of oxidative and inflammatory regulation is themain contributor to neurofunctional deterioration and failure of rebuilding spared neural networks after spinal cord injury(SCI).As an emerging biosafe strategy...Imbalance of oxidative and inflammatory regulation is themain contributor to neurofunctional deterioration and failure of rebuilding spared neural networks after spinal cord injury(SCI).As an emerging biosafe strategy for protecting against oxidative and inflammatory damage,hydrogen(H_(2))therapy is a promising approach for improving the microenvironment to allow neural regeneration.However,achieving release of H_(2) at sufficient concentrations specifically into the injured area is critical for the therapeutic effect of H_(2).Thus,we assembled SiO_(2)@mSiO_(2) mesoporous silica nanoparticles and loaded them with ammonia borane(AB),which has abundant capacity and allows controllable release of H_(2) in an acid-dependent manner.The release of H_(2) from AB/SiO_(2)@mSiO_(2) was satisfactory at pH 6.6,which is approximately equal to the microenvironmental acidity after SCI.After AB/SiO_(2)@mSiO_(2) were intrathecally administered to ratmodels of SCI,continuous release of H_(2) fromthese nanoparticles synergistically enhanced neurofunctional recovery,reduced fibrotic scar formation and promoted neural regeneration by suppressing oxidative stress reaction.Furthermore,in the subacute phase of SCI,microglia were markedly polarized toward the M2 phenotype by H_(2) via inhibition of TLR9 expression in astrocytes.In conclusion,H_(2) delivery through AB/SiO_(2)@mSiO_(2) has the potential to efficiently treat SCI through comprehensivemodulation of the oxidative and inflammatory imbalance in themicroenvironment.展开更多
基金National Natural Science Foundation of China(62075026, 61875028)National Key Research and Development Program of China (2019YFB2203202)+2 种基金Liaoning Revitalization Talents Program (XLYC2002111)Program for Liaoning Excellent Talents in University(LR2019017)Fundamental Research Funds for the Central Universities (DUT22ZD202)。
文摘In-band full-duplex(IBFD) technology can double the spectrum utilization efficiency for wireless communications,and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-interference is the major challenge for the application of IBFD technology, which must be resolved. Compared with the conventional electronic method, the photonic self-interference cancellation(PSIC) technique has the advantages of wide bandwidth, high amplitude and time delay tuning precision, and immunity to electromagnetic interference.Integrating the PSIC system on chip can effectively reduce the size, weight, and power consumption and meet the application requirement, especially for mobile terminals and small satellite payloads. In this paper, the silicon integrated PSIC chip is presented first and demonstrated for IBFD communication. The integrated PSIC chip comprises function units including phase modulation, time delay and amplitude tuning, sideband filtering, and photodetection, which complete the matching conditions for RF self-interference cancellation. Over the wide frequency range of C, X, Ku, and K bands, from 5 GHz to 25 GHz, a cancellation depth of more than 20 dB is achieved with the narrowest bandwidth of 140 MHz. A maximum bandwidth of 630 MHz is obtained at a center frequency of10 GHz. The full-duplex communication experiment at Ku-band by using the PSIC chip is carried out. Cancellation depths of 24.9 dB and 26.6 dB are measured for a bandwidth of 100 MHz at central frequencies of 12.4 GHz and14.2 GHz, respectively, and the signal of interest(SOI) with 16-quadrature amplitude modulation is recovered successfully. The factors affecting the cancellation depth and maximum interference to the SOI ratio are investigated in detail. The performances of the integrated PSIC system including link gain, noise figure, receiving sensitivity, and spurious free dynamic range are characterized.
基金supported by the National Natural Science Foundation of China(81772445)the Natural Science Foundation of Shanghai,China(20ZR1469800)+1 种基金the Shanghai Sailing Program(19YF1448400)the National Science Foundation for Post-doctoral Scientists of China(2020M683733).
文摘Imbalance of oxidative and inflammatory regulation is themain contributor to neurofunctional deterioration and failure of rebuilding spared neural networks after spinal cord injury(SCI).As an emerging biosafe strategy for protecting against oxidative and inflammatory damage,hydrogen(H_(2))therapy is a promising approach for improving the microenvironment to allow neural regeneration.However,achieving release of H_(2) at sufficient concentrations specifically into the injured area is critical for the therapeutic effect of H_(2).Thus,we assembled SiO_(2)@mSiO_(2) mesoporous silica nanoparticles and loaded them with ammonia borane(AB),which has abundant capacity and allows controllable release of H_(2) in an acid-dependent manner.The release of H_(2) from AB/SiO_(2)@mSiO_(2) was satisfactory at pH 6.6,which is approximately equal to the microenvironmental acidity after SCI.After AB/SiO_(2)@mSiO_(2) were intrathecally administered to ratmodels of SCI,continuous release of H_(2) fromthese nanoparticles synergistically enhanced neurofunctional recovery,reduced fibrotic scar formation and promoted neural regeneration by suppressing oxidative stress reaction.Furthermore,in the subacute phase of SCI,microglia were markedly polarized toward the M2 phenotype by H_(2) via inhibition of TLR9 expression in astrocytes.In conclusion,H_(2) delivery through AB/SiO_(2)@mSiO_(2) has the potential to efficiently treat SCI through comprehensivemodulation of the oxidative and inflammatory imbalance in themicroenvironment.
