A backward wave amplifier(BWA) in a terahertz regime with a novel slow-wave structure(SWS) composed of multi parallel grating pins inside a rectangular waveguide is analyzed. The multi-pin rectangular waveguide SWS po...A backward wave amplifier(BWA) in a terahertz regime with a novel slow-wave structure(SWS) composed of multi parallel grating pins inside a rectangular waveguide is analyzed. The multi-pin rectangular waveguide SWS possesses good performance and is compatible with micro-fabrication technologies. The dispersion and interaction impedance of the multipin SWS are presented. The stopbands of the modes cling together in a Brillouim zone. The SWS has a high interaction impedance that is suitable for the interaction of multi cylindrical beams. The design, which is based on three parallel pins supporting the wave–beam interaction with four cylindrical beams, is verified by three-dimensional particle-in-cell simulations. A BWA with the central frequency at 340 GHz is demonstrated, and the output power is more than 100 m W.A tuning frequency range of 15 GHz(333–348 GHz) is obtained with a gain of more than 20 d B.展开更多
Although extensively studied, the exact role of sleep in learning and memory is still not very clear. Sleep deprivation has been most frequently used to explore the effects of sleep on learning and memory, but the res...Although extensively studied, the exact role of sleep in learning and memory is still not very clear. Sleep deprivation has been most frequently used to explore the effects of sleep on learning and memory, but the results from such studies are inevitably complicated by concurrent stress and distress. Furthermore, it is not clear whether there is a strict time-window between sleep and memory consolidation. In the present study we were able to induce time-locked slow-wave sleep(SWS) in mice by optogenetically stimulating GABAergic neurons in the parafacial zone(PZ), providing a direct approach to analyze the influences of SWS on learning and memory with precise time-windows. We found that SWS induced by light for 30 min immediately or 15 min after the training phase of the object-in-place task significantly prolonged the memory from 30 min to 6 h. However, induction of SWS 30 min after the training phase did not improve memory, suggesting a critical time-window between the induction of a brief episode of SWS and learning for memory consolidation.Application of a gentle touch to the mice during light stimulation to prevent SWS induction also failed to improve memory, indicating the specific role of SWS,but not the activation of PZ GABAergic neurons itself, in memory consolidation. Similar influences of light-induced SWS on memory consolidation also occurred for Y-maze spatial memory and contextual fear memory, but not for cued fear memory. SWS induction immediately before the test phase had no effect on memory performance, indicating that SWS does not affect memory retrieval. Thus, by induction of a brief-episode SWS we have revealed a critical time window for the consolidation of hippocampusdependent memory.展开更多
癫痫性电持续状态(electrographic status epilepticus,ESE)是指醒-睡各期棘慢波接近持续发放,是一种特殊的脑电图现象。相关概念还有慢波睡眠中电持续状态癫痫性脑病(epileptic encephalopathy with electrical status epilepticus dur...癫痫性电持续状态(electrographic status epilepticus,ESE)是指醒-睡各期棘慢波接近持续发放,是一种特殊的脑电图现象。相关概念还有慢波睡眠中电持续状态癫痫性脑病(epileptic encephalopathy with electrical status epilepticus during slow wave sleep,ECSWS)、睡眠中癫痫性电持续状态(electrical status epilepticus during sleep,ESES)、亚临床癫痫电发作(electrographic Seizures,ESz)等。以上术语临床应用广泛,但尚缺乏统一判定标准,存在滥用和误用现象。厘清相关概念对于科研和临床实践均具有重要意义。展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2014CB339801)the National High Technology Research and Development Program of China(Grant No.G060104012AA8122007B)
文摘A backward wave amplifier(BWA) in a terahertz regime with a novel slow-wave structure(SWS) composed of multi parallel grating pins inside a rectangular waveguide is analyzed. The multi-pin rectangular waveguide SWS possesses good performance and is compatible with micro-fabrication technologies. The dispersion and interaction impedance of the multipin SWS are presented. The stopbands of the modes cling together in a Brillouim zone. The SWS has a high interaction impedance that is suitable for the interaction of multi cylindrical beams. The design, which is based on three parallel pins supporting the wave–beam interaction with four cylindrical beams, is verified by three-dimensional particle-in-cell simulations. A BWA with the central frequency at 340 GHz is demonstrated, and the output power is more than 100 m W.A tuning frequency range of 15 GHz(333–348 GHz) is obtained with a gain of more than 20 d B.
基金supported by grants from the National Natural Science Foundation of China (31771167 and 31571090)the National Basic Research Development Program of China (2016YFC1306700)+1 种基金the Non-profit Central Research Institute Fund of the Chinese Academy of Medical Sciences (2018PT31041)the Fundamental Research Funds for the Central Universities of China (2017FZA7003)
文摘Although extensively studied, the exact role of sleep in learning and memory is still not very clear. Sleep deprivation has been most frequently used to explore the effects of sleep on learning and memory, but the results from such studies are inevitably complicated by concurrent stress and distress. Furthermore, it is not clear whether there is a strict time-window between sleep and memory consolidation. In the present study we were able to induce time-locked slow-wave sleep(SWS) in mice by optogenetically stimulating GABAergic neurons in the parafacial zone(PZ), providing a direct approach to analyze the influences of SWS on learning and memory with precise time-windows. We found that SWS induced by light for 30 min immediately or 15 min after the training phase of the object-in-place task significantly prolonged the memory from 30 min to 6 h. However, induction of SWS 30 min after the training phase did not improve memory, suggesting a critical time-window between the induction of a brief episode of SWS and learning for memory consolidation.Application of a gentle touch to the mice during light stimulation to prevent SWS induction also failed to improve memory, indicating the specific role of SWS,but not the activation of PZ GABAergic neurons itself, in memory consolidation. Similar influences of light-induced SWS on memory consolidation also occurred for Y-maze spatial memory and contextual fear memory, but not for cued fear memory. SWS induction immediately before the test phase had no effect on memory performance, indicating that SWS does not affect memory retrieval. Thus, by induction of a brief-episode SWS we have revealed a critical time window for the consolidation of hippocampusdependent memory.
文摘癫痫性电持续状态(electrographic status epilepticus,ESE)是指醒-睡各期棘慢波接近持续发放,是一种特殊的脑电图现象。相关概念还有慢波睡眠中电持续状态癫痫性脑病(epileptic encephalopathy with electrical status epilepticus during slow wave sleep,ECSWS)、睡眠中癫痫性电持续状态(electrical status epilepticus during sleep,ESES)、亚临床癫痫电发作(electrographic Seizures,ESz)等。以上术语临床应用广泛,但尚缺乏统一判定标准,存在滥用和误用现象。厘清相关概念对于科研和临床实践均具有重要意义。
