Neural tract tracing is used to study neural pathways and evaluate neuronal regeneration following nerve injuries.However,it is not always clear which tracer should be used to yield optimal results.In this study,we ex...Neural tract tracing is used to study neural pathways and evaluate neuronal regeneration following nerve injuries.However,it is not always clear which tracer should be used to yield optimal results.In this study,we examined the use of Alexa Fluor 488-conjugated cholera toxin subunit B(AF488-CTB).This was injected into the gastrocnemius muscle of rats,and it was found that motor,sensory,and sympathetic neurons were labeled in the spinal ventral horn,dorsal root ganglia,and sympathetic chain,respectively.Similar results were obtained when we injected AF594-CTB into the tibialis anterior muscle.The morphology and number of neurons were evaluated at different time points following the AF488-CTB injection.It was found that labeled motor and sensory neurons could be observed 12 hours post-injection.The intensity was found to increase over time,and the morphology appeared clear and complete 3-7 days post-injection,with clearly distinguishable motor neuron axons and dendrites.However,14 days after the injection,the quality of the images decreased and the neurons appeared blurred and incomplete.Nissl and immunohistochemical staining showed that the AF488-CTB-labeled neurons retained normal neurochemical and morphological features,and the surrounding microglia were also found to be unaltered.Overall,these results imply that the cholera toxin subunit B,whether unconjugated or conjugated with Alexa Fluor,is effective for retrograde tracing in muscular tissues and that it would also be suitable for evaluating the regeneration or degeneration of injured nerves.展开更多
Femtosecond laser filamentation has recently emerged as a promising technique to actively create a channel through clouds and fog,thereby providing a revolutionary opportunity to overcome the obstacle of fog-induced a...Femtosecond laser filamentation has recently emerged as a promising technique to actively create a channel through clouds and fog,thereby providing a revolutionary opportunity to overcome the obstacle of fog-induced attenuation for free-space optical communication(FSOC)in atmosphere.However,the underlying physics remains elusive,which is critical for optimizing time window and efficiency of guiding light in this channel.In this work,the time evolution of the filament-induced channel is investigated under various laser pulse energies and repetition rates.The combined diffusion model is built to reveal the contributions of gas molecules and aerosol droplets in competition of guiding and defocusing effect of the filament-induced channel.The related findings can deepen our understanding on the underlying physics of the air channel induced by the filament,provide insight into the optimizing time window and efficiency of guiding light,and potentially contribute to the improvement of filament-assisted FSOC.展开更多
基金supported by the CACMS Innovation Fund,No.CI2021A03407(to WZB)the Project of National Key R&D Program of China,No.2019YFC1709103(to WZB)+1 种基金the National Natural Science Foundation of China,Nos.81774432(to JJC),81774211(to WZB),82004492(to JW),81801561(to DSX)the Fundamental Research Funds for the Central Public Welfare Research Institutes of China,Nos.ZZ13-YQ-068(to JJC),ZZ14-YQ-032(to JW),ZZ14-YQ-034(to DSX).
文摘Neural tract tracing is used to study neural pathways and evaluate neuronal regeneration following nerve injuries.However,it is not always clear which tracer should be used to yield optimal results.In this study,we examined the use of Alexa Fluor 488-conjugated cholera toxin subunit B(AF488-CTB).This was injected into the gastrocnemius muscle of rats,and it was found that motor,sensory,and sympathetic neurons were labeled in the spinal ventral horn,dorsal root ganglia,and sympathetic chain,respectively.Similar results were obtained when we injected AF594-CTB into the tibialis anterior muscle.The morphology and number of neurons were evaluated at different time points following the AF488-CTB injection.It was found that labeled motor and sensory neurons could be observed 12 hours post-injection.The intensity was found to increase over time,and the morphology appeared clear and complete 3-7 days post-injection,with clearly distinguishable motor neuron axons and dendrites.However,14 days after the injection,the quality of the images decreased and the neurons appeared blurred and incomplete.Nissl and immunohistochemical staining showed that the AF488-CTB-labeled neurons retained normal neurochemical and morphological features,and the surrounding microglia were also found to be unaltered.Overall,these results imply that the cholera toxin subunit B,whether unconjugated or conjugated with Alexa Fluor,is effective for retrograde tracing in muscular tissues and that it would also be suitable for evaluating the regeneration or degeneration of injured nerves.
基金supported by the National Natural Science Foundation of China(12074198 and 62105042).
文摘Femtosecond laser filamentation has recently emerged as a promising technique to actively create a channel through clouds and fog,thereby providing a revolutionary opportunity to overcome the obstacle of fog-induced attenuation for free-space optical communication(FSOC)in atmosphere.However,the underlying physics remains elusive,which is critical for optimizing time window and efficiency of guiding light in this channel.In this work,the time evolution of the filament-induced channel is investigated under various laser pulse energies and repetition rates.The combined diffusion model is built to reveal the contributions of gas molecules and aerosol droplets in competition of guiding and defocusing effect of the filament-induced channel.The related findings can deepen our understanding on the underlying physics of the air channel induced by the filament,provide insight into the optimizing time window and efficiency of guiding light,and potentially contribute to the improvement of filament-assisted FSOC.
