Ultrasonic neuromodulation has gained recognition as a promising therapeutic approach.A miniature transducer capable of generating suitable-strength and broadband ultrasound is of great significance for achieving high...Ultrasonic neuromodulation has gained recognition as a promising therapeutic approach.A miniature transducer capable of generating suitable-strength and broadband ultrasound is of great significance for achieving high spatial precision ultrasonic neural stimulation.However,the ultrasound transducer with the above integrated is yet to be challenged.Here,we developed a fiber-optic photoacoustic emitter(FPE)with a diameter of 200μm,featuring controllable sound intensity and a broadband response(−6 dB bandwidth:162%).The device integrates MXene(Ti_(3)C_(2)Tx),known for its exceptional photothermal properties,and polydimethylsiloxane,which offers a high thermal expansion coefficient.This FPE,exhibiting high spatial precision(lateral:163.3μm,axial:207μm),is capable of selectively activating neurons in targeted regions.Using the TetTagging method to selectively express a cfos-promoter-inducible mCHERRY gene within the medial prefrontal cortex(mPFC),we found that photoacoustic stimulation significantly and temporarily activated the neurons.In vivo fiber photometry demonstrated that photoacoustic stimulation induced substantial calcium transients in mPFC neurons.Furthermore,we confirmed that photoacoustic stimulation of the mPFC using FPE markedly alleviates acute social defeat stress-induced emotional stress in mice.This work demonstrates the potential of FPEs for clinical applications,with a particular focus on modulating neural activity to regulate emotions.展开更多
Cerium oxide nanoparticles(CeO_(2) NPs)are likely to have dramatic impacts on plant performances,yet the effects of CeO_(2) NPs on seed germination and seedling growth have not been fully explored.In this study,the se...Cerium oxide nanoparticles(CeO_(2) NPs)are likely to have dramatic impacts on plant performances,yet the effects of CeO_(2) NPs on seed germination and seedling growth have not been fully explored.In this study,the seed germination and seedling growth of subshrub species Vitex negundo under different concentrations of CeO_(2) NPs(low-1 mg/L,medium-100 mg/L,high-500 mg/L)have been discussed.Results showed that:(1)The seed germination rate reduces by 11.25%and 2.5%under the low and medium concentrations of CeO_(2) NPs,respectively,but increased by 7.08%under the high concentration;(2)CeO_(2) NPs had significant effects on the growth traits(root length,shoot height and biomass)of seedlings,being the highest under the medium concentration and the lowest under the highest concentration;(3)The superoxide dismutase activity was the maximum(355.91 U/g),but the protein concentration was the minimum(3.85 ug/mL)under the high concentration of CeO_(2) NPs.Our results indicated that the effects of CeO_(2) NPs on seed germination and seedling growth are concentration-dependency,i.e.,low and medium concentrations inhibited while high concentration promoted seed germination,however,seedling growth showed opposite responses.Therefore,appropriate CeO_(2) NPs concentrations are beneficial to the seed germination and seedling growth of Vitex negundo and improve the physiological performance of seedlings and enhance their adaptability to environmental adversity.展开更多
This paper focuses on analyzing the ergodic capacity performance of limited feedback (LFB) beamforming in multi-user distributed antenna system (DAS). In such a system, multi-user interference (MUI) is inevitably due ...This paper focuses on analyzing the ergodic capacity performance of limited feedback (LFB) beamforming in multi-user distributed antenna system (DAS). In such a system, multi-user interference (MUI) is inevitably due to the channel uncertainties caused by quantization error. Considering this, we propose a parameter named effective ergodic capacity rate (EECR), which denotes the capacity offset between finite rate feedback and perfect channel state information (CSI). The simulation results show that the derived approximated EECR is very tight to actual EECR. Based on the approximated EECR, an adaptive minimum bit feedback scheme is proposed, which can effectively reduce the overhead of feedback channel and the complexity of the system. The simulation results verify the effectiveness of the proposed scheme.展开更多
An optical multi-component gas detection system based on the conjugated interferometer （CI） is proposed and experimentally demonstrated. It can realize the concentration detection of mixture gas in the environment. ...An optical multi-component gas detection system based on the conjugated interferometer （CI） is proposed and experimentally demonstrated. It can realize the concentration detection of mixture gas in the environment. The CI can transform the absorption spectrum of the target gases to a conjugated emission spectrum, when combining the CI with the broadband light source, the spectrum of output light matches well with the absorption spectrum of target gases. The CI design for different target gases can be achieved by replacing the kind of target absorbing gas in the CI filter. The traditional fiber gas sensor system requires multiple light sources for detection when there are several kinds of gases, and this problem has been solved by using the CI filter combined with the broadband light source. The experimental results show that the system can detect the concentration of multi-component gases, which are mixed with C2H2 and NH3. Experimental results also show a good concentration sensing linearity.展开更多
The use of magneto-mechanical force to kill cancer cells has attracted significant attention in recent years.However,many reports have focused on in vitro experiments with a single treatment.Herein,CaO_(2)-coated Fe_(...The use of magneto-mechanical force to kill cancer cells has attracted significant attention in recent years.However,many reports have focused on in vitro experiments with a single treatment.Herein,CaO_(2)-coated Fe_(3)O_(4)core–shell magnetic nanoenzymes(Fe_(3)O_(4)/CaO_(2))are developed for low frequency vibrating magnetic field(VMF)-induced multimodal cancer therapy.Fe_(3)O_(4)/CaO_(2)are shown to efficiently generate O_(2),H_(2)O_(2),·OH through hydrolysis of CaO_(2)and a CaO_(2)-strengthened Fenton reaction,killing laryngeal carcinoma cells and inhibiting mouse tumor growth(chemodynamic therapy(CDT)).Both Fe_(3)O_(4)and Fe_(3)O_(4)/CaO_(2)triggered by a VMF are shown to damage the cytoskeleton of cancer cells through magneto-mechanical force(maxima:223 piconewtons or larger by Fe_(3)O_(4)/CaO_(2)aggregations)and induce the generation of intracellular reactive oxygen species(ROS),the VMF-triggered Fe_(3)O_(4)/CaO_(2)is shown to generate additional intracellular ROS.Upon exposure to a VMF,the cell killing efficiency and tumor growth inhibition were further significantly improved by Fe_(3)O_(4)/CaO_(2)through CDT,magnetomechanical force,force-induced ROS,the cytotoxicity of Ca^(2+)ions.In addition,the Fe_(3)O_(4)/CaO_(2)nanoenzymes and VMFinduced treatment are shown to be safe for mice.The results of this study open the door for treating solid tumors without inducing multidrug resistance through the combination of CDT and force.展开更多
Distributed optical fiber sensing exploring forward stimulated Brillouin scattering(FSBS)has received wide attention,as it indicates a new sensing method to measure the liquid property surrounding an optical fiber.In ...Distributed optical fiber sensing exploring forward stimulated Brillouin scattering(FSBS)has received wide attention,as it indicates a new sensing method to measure the liquid property surrounding an optical fiber.In the existing techniques,backward stimulated Brillouin scattering is adopted for detection of the sensing signal,which requires time-consuming signal acquisition and post-processing.In this work,an approach that distributedly measures FSBS spectra is proposed and demonstrated based on coherent detection.While an excitation pulse with single-frequency amplitude modulation is used to induce a guided acoustic mode in the fiber,a following pulse is adopted to probe the induced phase modulation.Using a chirped fiber Bragg grating array,an enhancedbackward-propagating sensing signal is generated from the probe pulse.Heterodyne coherent-detection-based phase demodulation is then realized by mixing the sensing signal with a local oscillator.The FSBS spectra can then be reconstructed from the beat signals with only one round of frequency sweeping.With significantly accelerated signal acquisition and simplified post-processing,the proposed distributed acoustic sensing system has achieved spatial resolution of 5 m over a 500-m sensing range.展开更多
基金supported by the National Nature Science Foundation of China(Grant Number:U24A20306,12102140,6227031087,62035006,and 6207030117).
文摘Ultrasonic neuromodulation has gained recognition as a promising therapeutic approach.A miniature transducer capable of generating suitable-strength and broadband ultrasound is of great significance for achieving high spatial precision ultrasonic neural stimulation.However,the ultrasound transducer with the above integrated is yet to be challenged.Here,we developed a fiber-optic photoacoustic emitter(FPE)with a diameter of 200μm,featuring controllable sound intensity and a broadband response(−6 dB bandwidth:162%).The device integrates MXene(Ti_(3)C_(2)Tx),known for its exceptional photothermal properties,and polydimethylsiloxane,which offers a high thermal expansion coefficient.This FPE,exhibiting high spatial precision(lateral:163.3μm,axial:207μm),is capable of selectively activating neurons in targeted regions.Using the TetTagging method to selectively express a cfos-promoter-inducible mCHERRY gene within the medial prefrontal cortex(mPFC),we found that photoacoustic stimulation significantly and temporarily activated the neurons.In vivo fiber photometry demonstrated that photoacoustic stimulation induced substantial calcium transients in mPFC neurons.Furthermore,we confirmed that photoacoustic stimulation of the mPFC using FPE markedly alleviates acute social defeat stress-induced emotional stress in mice.This work demonstrates the potential of FPEs for clinical applications,with a particular focus on modulating neural activity to regulate emotions.
基金This study was supported by the Science and Technology Innovation Foundation of Henan Agricultural University(30601458)the Scientific Research Foundation for the Doctor of Henan Agriculture University(30500848).
文摘Cerium oxide nanoparticles(CeO_(2) NPs)are likely to have dramatic impacts on plant performances,yet the effects of CeO_(2) NPs on seed germination and seedling growth have not been fully explored.In this study,the seed germination and seedling growth of subshrub species Vitex negundo under different concentrations of CeO_(2) NPs(low-1 mg/L,medium-100 mg/L,high-500 mg/L)have been discussed.Results showed that:(1)The seed germination rate reduces by 11.25%and 2.5%under the low and medium concentrations of CeO_(2) NPs,respectively,but increased by 7.08%under the high concentration;(2)CeO_(2) NPs had significant effects on the growth traits(root length,shoot height and biomass)of seedlings,being the highest under the medium concentration and the lowest under the highest concentration;(3)The superoxide dismutase activity was the maximum(355.91 U/g),but the protein concentration was the minimum(3.85 ug/mL)under the high concentration of CeO_(2) NPs.Our results indicated that the effects of CeO_(2) NPs on seed germination and seedling growth are concentration-dependency,i.e.,low and medium concentrations inhibited while high concentration promoted seed germination,however,seedling growth showed opposite responses.Therefore,appropriate CeO_(2) NPs concentrations are beneficial to the seed germination and seedling growth of Vitex negundo and improve the physiological performance of seedlings and enhance their adaptability to environmental adversity.
基金Sponsored by the National High Technology Research and Development Program of China(Grant No.2006AA01Z272 and 2009AA02Z412)the Beijing Municipal Science & Technology Commission(Grant No.D08080100620802)
文摘This paper focuses on analyzing the ergodic capacity performance of limited feedback (LFB) beamforming in multi-user distributed antenna system (DAS). In such a system, multi-user interference (MUI) is inevitably due to the channel uncertainties caused by quantization error. Considering this, we propose a parameter named effective ergodic capacity rate (EECR), which denotes the capacity offset between finite rate feedback and perfect channel state information (CSI). The simulation results show that the derived approximated EECR is very tight to actual EECR. Based on the approximated EECR, an adaptive minimum bit feedback scheme is proposed, which can effectively reduce the overhead of feedback channel and the complexity of the system. The simulation results verify the effectiveness of the proposed scheme.
基金Acknowledgment This research was supported by the Natural National Science Foundation of China, NSFC （Grant No. 61575149, 61290311）, and the Major Project of Hubei Technological Innovation Special Fund （2016AAA008）.
文摘An optical multi-component gas detection system based on the conjugated interferometer （CI） is proposed and experimentally demonstrated. It can realize the concentration detection of mixture gas in the environment. The CI can transform the absorption spectrum of the target gases to a conjugated emission spectrum, when combining the CI with the broadband light source, the spectrum of output light matches well with the absorption spectrum of target gases. The CI design for different target gases can be achieved by replacing the kind of target absorbing gas in the CI filter. The traditional fiber gas sensor system requires multiple light sources for detection when there are several kinds of gases, and this problem has been solved by using the CI filter combined with the broadband light source. The experimental results show that the system can detect the concentration of multi-component gases, which are mixed with C2H2 and NH3. Experimental results also show a good concentration sensing linearity.
基金the National Natural Science Foundation of China(No.31570960)Open Funding Project of the State Key Laboratory of Bioreactor Engineering.
文摘The use of magneto-mechanical force to kill cancer cells has attracted significant attention in recent years.However,many reports have focused on in vitro experiments with a single treatment.Herein,CaO_(2)-coated Fe_(3)O_(4)core–shell magnetic nanoenzymes(Fe_(3)O_(4)/CaO_(2))are developed for low frequency vibrating magnetic field(VMF)-induced multimodal cancer therapy.Fe_(3)O_(4)/CaO_(2)are shown to efficiently generate O_(2),H_(2)O_(2),·OH through hydrolysis of CaO_(2)and a CaO_(2)-strengthened Fenton reaction,killing laryngeal carcinoma cells and inhibiting mouse tumor growth(chemodynamic therapy(CDT)).Both Fe_(3)O_(4)and Fe_(3)O_(4)/CaO_(2)triggered by a VMF are shown to damage the cytoskeleton of cancer cells through magneto-mechanical force(maxima:223 piconewtons or larger by Fe_(3)O_(4)/CaO_(2)aggregations)and induce the generation of intracellular reactive oxygen species(ROS),the VMF-triggered Fe_(3)O_(4)/CaO_(2)is shown to generate additional intracellular ROS.Upon exposure to a VMF,the cell killing efficiency and tumor growth inhibition were further significantly improved by Fe_(3)O_(4)/CaO_(2)through CDT,magnetomechanical force,force-induced ROS,the cytotoxicity of Ca^(2+)ions.In addition,the Fe_(3)O_(4)/CaO_(2)nanoenzymes and VMFinduced treatment are shown to be safe for mice.The results of this study open the door for treating solid tumors without inducing multidrug resistance through the combination of CDT and force.
基金National Natural Science Foundation of China(62075171,61905184,61735013)。
文摘Distributed optical fiber sensing exploring forward stimulated Brillouin scattering(FSBS)has received wide attention,as it indicates a new sensing method to measure the liquid property surrounding an optical fiber.In the existing techniques,backward stimulated Brillouin scattering is adopted for detection of the sensing signal,which requires time-consuming signal acquisition and post-processing.In this work,an approach that distributedly measures FSBS spectra is proposed and demonstrated based on coherent detection.While an excitation pulse with single-frequency amplitude modulation is used to induce a guided acoustic mode in the fiber,a following pulse is adopted to probe the induced phase modulation.Using a chirped fiber Bragg grating array,an enhancedbackward-propagating sensing signal is generated from the probe pulse.Heterodyne coherent-detection-based phase demodulation is then realized by mixing the sensing signal with a local oscillator.The FSBS spectra can then be reconstructed from the beat signals with only one round of frequency sweeping.With significantly accelerated signal acquisition and simplified post-processing,the proposed distributed acoustic sensing system has achieved spatial resolution of 5 m over a 500-m sensing range.
