Stressful stimuli induced by immobilization are perceived as acute stress in rats. This acute stress activates corticotropin-releasing hormone (CRH) neurons in the hypothalamic paraventricular nucleus (PVN), resulting...Stressful stimuli induced by immobilization are perceived as acute stress in rats. This acute stress activates corticotropin-releasing hormone (CRH) neurons in the hypothalamic paraventricular nucleus (PVN), resulting in stimulation of the hypothalamic-pituitary-adrenal (HPA) axis. The ventral ascending noradrenergic bundles (V-NAB) from the brainstem innervate the PVN. To investigate the relationship between the response of the HPA axis and the V-NAB, we examined changes in plasma corticosterone, the final output of the HPA axis, and extracellular noradrenaline (NA) in the PVN following immobilization stress in rats that received bilateral 6-hydroxydopamine (6-OHDA) lesions of the V-NAB. 6-OHDA microinjection into the V-NAB reduced the magnitude of the responses of plasma corticosterone and extracellular NA in the PVN following immobilization stress. Our results suggest that V-NAB innervation of the PVN is involved in immobilization stress-induced activation of the HPA axis.展开更多
On March 29,2022,the Long March 6A launch vehicle developed by the Shanghai Academy of Space-flight Technology successfully made its maiden flight at the Taiyuan Satellite Launch Center.The Long March 6A launch vehicl...On March 29,2022,the Long March 6A launch vehicle developed by the Shanghai Academy of Space-flight Technology successfully made its maiden flight at the Taiyuan Satellite Launch Center.The Long March 6A launch vehicle was China’s first solid bundled rocket.It uses non-toxic and non-polluting propellants,and has a 700 km sun-synchronous orbit carrying capacity of no less than 4.5 t,which is more than 50%higher than that of a LM-4C launch vehicle.During the development of the LM-6A launch vehicle,the matching relationship between systems and the overall performance of the entire rocket improved significantly through continuous overall optimization work.This paper introduces the typical overall optimization work during the development of the LM-6A launch vehicle.展开更多
Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several hours.To correct the bias of an NWP model and improve the accuracy of ...Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several hours.To correct the bias of an NWP model and improve the accuracy of short-range precipitation forecasting,we propose a deep learning-based approach called UNet Mask,which combines NWP forecasts with the output of a convolutional neural network called UNet.The UNet Mask involves training the UNet on historical data from the NWP model and gridded rainfall observations for 6-hour precipitation forecasting.The overlap of the UNet output and the NWP forecasts at the same rainfall threshold yields a mask.The UNet Mask blends the UNet output and the NWP forecasts by taking the maximum between them and passing through the mask,which provides the corrected 6-hour rainfall forecasts.We evaluated UNet Mask on a test set and in real-time verification.The results showed that UNet Mask outperforms the NWP model in 6-hour precipitation prediction by reducing the FAR and improving CSI scores.Sensitivity tests also showed that different small rainfall thresholds applied to the UNet and the NWP model have different effects on UNet Mask's forecast performance.This study shows that UNet Mask is a promising approach for improving rainfall forecasting of NWP models.展开更多
为了探索高效的帕金森病大鼠模型的建立方法,通过黑质致密部(substantia nigra pars compacta,SNc)、中脑腹侧背盖区(ventral tegmental area,VTA)双位点注射和内侧前脑束(medial forebrain bundle,MFB)单位点注射6-羟基多巴胺2种方法...为了探索高效的帕金森病大鼠模型的建立方法,通过黑质致密部(substantia nigra pars compacta,SNc)、中脑腹侧背盖区(ventral tegmental area,VTA)双位点注射和内侧前脑束(medial forebrain bundle,MFB)单位点注射6-羟基多巴胺2种方法建立帕金森病大鼠模型;术后连续4周运用阿朴吗啡旋转试验鉴定模型是否成功,并用免疫组化方法验证大鼠的SNc多巴胺能神经元的损毁程度。结果表明:SNc-VTA组造模后1周成功率为12%,4周后成功率为72%,MFB组造模后1周成功率即达到84%,2周后的成功率则达到92%;采用2种方法均可成功建立帕金森病大鼠模型,但MFB单位点注射法在短时间内具有更高的成功率。展开更多
文摘Stressful stimuli induced by immobilization are perceived as acute stress in rats. This acute stress activates corticotropin-releasing hormone (CRH) neurons in the hypothalamic paraventricular nucleus (PVN), resulting in stimulation of the hypothalamic-pituitary-adrenal (HPA) axis. The ventral ascending noradrenergic bundles (V-NAB) from the brainstem innervate the PVN. To investigate the relationship between the response of the HPA axis and the V-NAB, we examined changes in plasma corticosterone, the final output of the HPA axis, and extracellular noradrenaline (NA) in the PVN following immobilization stress in rats that received bilateral 6-hydroxydopamine (6-OHDA) lesions of the V-NAB. 6-OHDA microinjection into the V-NAB reduced the magnitude of the responses of plasma corticosterone and extracellular NA in the PVN following immobilization stress. Our results suggest that V-NAB innervation of the PVN is involved in immobilization stress-induced activation of the HPA axis.
文摘On March 29,2022,the Long March 6A launch vehicle developed by the Shanghai Academy of Space-flight Technology successfully made its maiden flight at the Taiyuan Satellite Launch Center.The Long March 6A launch vehicle was China’s first solid bundled rocket.It uses non-toxic and non-polluting propellants,and has a 700 km sun-synchronous orbit carrying capacity of no less than 4.5 t,which is more than 50%higher than that of a LM-4C launch vehicle.During the development of the LM-6A launch vehicle,the matching relationship between systems and the overall performance of the entire rocket improved significantly through continuous overall optimization work.This paper introduces the typical overall optimization work during the development of the LM-6A launch vehicle.
基金jointly supported by the National Natural Science Foundation of China(Grant No.U1811464)the Hydraulic Innovation Project of Science and Technology of Guangdong Province of China(Grant No.2022-01)the Guangzhou Basic and Applied Basic Research Foundation(Grant No.202201011472)。
文摘Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several hours.To correct the bias of an NWP model and improve the accuracy of short-range precipitation forecasting,we propose a deep learning-based approach called UNet Mask,which combines NWP forecasts with the output of a convolutional neural network called UNet.The UNet Mask involves training the UNet on historical data from the NWP model and gridded rainfall observations for 6-hour precipitation forecasting.The overlap of the UNet output and the NWP forecasts at the same rainfall threshold yields a mask.The UNet Mask blends the UNet output and the NWP forecasts by taking the maximum between them and passing through the mask,which provides the corrected 6-hour rainfall forecasts.We evaluated UNet Mask on a test set and in real-time verification.The results showed that UNet Mask outperforms the NWP model in 6-hour precipitation prediction by reducing the FAR and improving CSI scores.Sensitivity tests also showed that different small rainfall thresholds applied to the UNet and the NWP model have different effects on UNet Mask's forecast performance.This study shows that UNet Mask is a promising approach for improving rainfall forecasting of NWP models.
文摘为了探索高效的帕金森病大鼠模型的建立方法,通过黑质致密部(substantia nigra pars compacta,SNc)、中脑腹侧背盖区(ventral tegmental area,VTA)双位点注射和内侧前脑束(medial forebrain bundle,MFB)单位点注射6-羟基多巴胺2种方法建立帕金森病大鼠模型;术后连续4周运用阿朴吗啡旋转试验鉴定模型是否成功,并用免疫组化方法验证大鼠的SNc多巴胺能神经元的损毁程度。结果表明:SNc-VTA组造模后1周成功率为12%,4周后成功率为72%,MFB组造模后1周成功率即达到84%,2周后的成功率则达到92%;采用2种方法均可成功建立帕金森病大鼠模型,但MFB单位点注射法在短时间内具有更高的成功率。
