BACKGROUND:Limbic encephalitis is a rare syndrome that specifically affects the limbic system. Magnetic resonance imaging(MRI) has been typically used to detect brain changes in this disease. However,the mechanisms of...BACKGROUND:Limbic encephalitis is a rare syndrome that specifically affects the limbic system. Magnetic resonance imaging(MRI) has been typically used to detect brain changes in this disease. However,the mechanisms of limbic encephalitis-related white matter damage remain poorly understood. OBJECTIVE:To characterize white matter connectivity changes secondary to injuries of the limbic system in limbic encephalitis through combined application of diffusion tensor imaging(DTI) and voxel-based morphometry. DESIGN,TIME AND SETTING:A non-randomized,controlled,clinical,neuroimaging,DTI study was performed at the Department of Radiology,West China Hospital in December 2008. PARTICIPANTS:A male,46-year-old,limbic encephalitis patient,as well as 11 age- and gender-matched healthy volunteers,were enrolled in the present study. METHODS:MRI was performed on the limbic encephalitis patient using a 3.0T MR scanner. Three-dimensional SPGR T1-weighted images and DTI were acquired in the patient and controls. Data were analyzed using Matlab 7.0 and SPM2 software. MAIN OUTCOME MEASURES:Results from routine MRI scan with contrast enhancement of patient,as well as fractional anisotropy and mean diffusivity value map differences between patient and controls. RESULTS:Significant symmetric MRI signal intensity abnormalities were observed with routine MRI. Affected bilateral hippocampi and amygdala exhibited hypointense signals in T1WI and hyperintense signals in T2 images.The DTI study revealed decreased fractional anisotropy values in the bilateral alveus and fimbria of the hippocampus,bilateral internal and external capsules,white matter of the right prefrontal area,and left corona radiate in the patient compared with normal controls(P<0.001). Significantly increased fractional anisotropy,mean diffusivity,or decreased mean diffusivity were not observed in the patient,compared with controls. CONCLUSION:Secondary white matter damage to the hippocampal alveus and fimbria was apparent in the limbic encephalitis patient.In addition,other white matter fiber injuries surrounded the limbic structures,which were not attributed to secondary limbic system injuries.展开更多
Typhoon has an impact on an estuary and coastal environment.However,the present research lacks the detailed description of material transport processes during typhoon passage,such as the transport channels and barrier...Typhoon has an impact on an estuary and coastal environment.However,the present research lacks the detailed description of material transport processes during typhoon passage,such as the transport channels and barriers in the course of material transport and material accumulation area,etc.Therefore,Lagrangian coherent structures(a method developed for describing the transport structure of fluids in recent years)was introduced to investigate and predict the floating material and debris transport process in the Laizhou Bay,Bohai Sea,during typhoon Lekima in 2019.Results show that the Lagrangian coherent structure could well explain the complex flow phenomena in the bay.During the typhoon,the general direction of floating material transport in the Laizhou Bay was anticlockwise.There was a channel for material transport in the northwest and south of the bay,and there are transportation obstacles in the northeast-southwest direction in the middle of the bay.Therefore,the typhoon might worsen the water quality.These results provide references for precise countermeasures to control the formulation of pollution in the Laizhou Bay.展开更多
Erratum to:https://doi.org/10.1007/s00343-021-0384-7 The authors’affiliations of this article contain a few mistakes.The correct ones are given below:1 College of Environmental Science and Engineering,Ocean Universit...Erratum to:https://doi.org/10.1007/s00343-021-0384-7 The authors’affiliations of this article contain a few mistakes.The correct ones are given below:1 College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China 2 Key Laboratory of Marine Environment and Ecology,Ministry of Education of China,Ocean University of China,Qingdao 266100,China The online version of the original articles can be found at:https://doi.org/10.1007/s00343-021-0384-7.展开更多
An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching appro...An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching approximately 233 W.The active-locking of these coherently combined channels,followed by compression using gratings,yields an output with a pulse energy of 504μJ and an average power of 403 W.Exceptional stability is maintained,with a 0.3%root mean square(RMS)deviation and a beam quality factor M^(2)<1.2.Notably,precise dispersion management of the front-end seed light effectively compensates for the accumulated high-order dispersion in subsequent amplification stages.This strategic approach results in a significant reduction in the final output pulse duration for the coherently combined laser beam,reducing it from 488 to 260 fs after the gratings compressor,while concurrently enhancing the energy of the primary peak from 65%to 92%.展开更多
Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse...Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions,allows one to predict and understand the underlying physics of light interaction with matter,whose spatially resolved transient dielectric function experiences ultrafast evolution.However,such a task is technically challenging for two reasons:first,one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional(2D)detector;second,typical detectors are only sensitive to intensity or amplitude information rather than phase.Here we have demonstrated compressed optical field topography(COFT)drawing a 3D map for an ultrafast optical field in single-shot,by combining the coded aperture snapshot spectral imaging(CASSI)technique with a global 3D phase retrieval procedure.COFT can,in single-shot,fully characterize the spatiotemporal coupling of a femtosecond laser pulse,and live stream the light-speed propagation of an air plasma ionization front,unveiling its potential applications in ultrafast sciences.展开更多
Background:βAmyloid(Aβ)-mediated neuronal hyperactivity,a key feature of the early stage of Alzheimer’s disease(AD),is recently proposed to be initiated by the suppression of glutamate reuptake.Nevertheless,the und...Background:βAmyloid(Aβ)-mediated neuronal hyperactivity,a key feature of the early stage of Alzheimer’s disease(AD),is recently proposed to be initiated by the suppression of glutamate reuptake.Nevertheless,the underlying mechanism by which the impaired glutamate reuptake causes neuronal hyperactivity remains unclear.Chronic suppression of the glutamate reuptake causes accumulation of ambient glutamate that could difuse from synaptic sites at the dendrites to the soma to elevate the tonic activation of somatic N-methyl-D-aspartate receptors(NMDARs).However,less attention has been paid to the potential role of tonic activity change in extrasynaptic glutamate receptors(GluRs)located at the neuronal soma on generation of neuronal hyperactivity.Methods:Whole-cell patch-clamp recordings were performed on CA1 pyramidal neurons in acute hippocampal slices exposed to TFB-threo-β-benzyloxyaspartic acid(TBOA)or human Aβ_(1-42) peptide oligomer.A series of dendritic patch-clamp recordings were made at diferent distances from the soma to identify the location of the changes in synaptic inputs.Moreover,single-channel recording in the cell-attached mode was performed to investigate the activity changes of single NMDARs at the soma.Results:Blocking glutamate uptake with either TBOA or the human Aβ_(1-42) peptide oligomer elicited potentiation of synaptic inputs in CA1 hippocampal neurons.Strikingly,this potentiation specifcally occurred at the soma,depending on the activation of somatic GluN2B-containing NMDARs(GluN2B-NMDARs)and accompanied by a substantial and persistent increment in the open probability of somatic NMDARs.Blocking the activity of GluN2B-NMDARs at the soma completely reversed both the TBOA-induced or the Aβ_(1-42)-induced somatic potentiation and neuronal hyperactivity.Conclusions:The somatic potentiation of synaptic inputs may represent a novel amplifcation mechanism that elevates cell excitability and thus contributes to neuronal hyperactivity initiated by impaired glutamate reuptake in AD.展开更多
基金the National Natural Science Foundation of China,No.30800263
文摘BACKGROUND:Limbic encephalitis is a rare syndrome that specifically affects the limbic system. Magnetic resonance imaging(MRI) has been typically used to detect brain changes in this disease. However,the mechanisms of limbic encephalitis-related white matter damage remain poorly understood. OBJECTIVE:To characterize white matter connectivity changes secondary to injuries of the limbic system in limbic encephalitis through combined application of diffusion tensor imaging(DTI) and voxel-based morphometry. DESIGN,TIME AND SETTING:A non-randomized,controlled,clinical,neuroimaging,DTI study was performed at the Department of Radiology,West China Hospital in December 2008. PARTICIPANTS:A male,46-year-old,limbic encephalitis patient,as well as 11 age- and gender-matched healthy volunteers,were enrolled in the present study. METHODS:MRI was performed on the limbic encephalitis patient using a 3.0T MR scanner. Three-dimensional SPGR T1-weighted images and DTI were acquired in the patient and controls. Data were analyzed using Matlab 7.0 and SPM2 software. MAIN OUTCOME MEASURES:Results from routine MRI scan with contrast enhancement of patient,as well as fractional anisotropy and mean diffusivity value map differences between patient and controls. RESULTS:Significant symmetric MRI signal intensity abnormalities were observed with routine MRI. Affected bilateral hippocampi and amygdala exhibited hypointense signals in T1WI and hyperintense signals in T2 images.The DTI study revealed decreased fractional anisotropy values in the bilateral alveus and fimbria of the hippocampus,bilateral internal and external capsules,white matter of the right prefrontal area,and left corona radiate in the patient compared with normal controls(P<0.001). Significantly increased fractional anisotropy,mean diffusivity,or decreased mean diffusivity were not observed in the patient,compared with controls. CONCLUSION:Secondary white matter damage to the hippocampal alveus and fimbria was apparent in the limbic encephalitis patient.In addition,other white matter fiber injuries surrounded the limbic structures,which were not attributed to secondary limbic system injuries.
基金Supported by the National Natural Science Foundation of China(No.41974085)the National Key R&D Program of China(No.2019YFC1408100)。
文摘Typhoon has an impact on an estuary and coastal environment.However,the present research lacks the detailed description of material transport processes during typhoon passage,such as the transport channels and barriers in the course of material transport and material accumulation area,etc.Therefore,Lagrangian coherent structures(a method developed for describing the transport structure of fluids in recent years)was introduced to investigate and predict the floating material and debris transport process in the Laizhou Bay,Bohai Sea,during typhoon Lekima in 2019.Results show that the Lagrangian coherent structure could well explain the complex flow phenomena in the bay.During the typhoon,the general direction of floating material transport in the Laizhou Bay was anticlockwise.There was a channel for material transport in the northwest and south of the bay,and there are transportation obstacles in the northeast-southwest direction in the middle of the bay.Therefore,the typhoon might worsen the water quality.These results provide references for precise countermeasures to control the formulation of pollution in the Laizhou Bay.
基金Supported by the National Natural Science Foundation of China(No.41974085)the National Key R&D Program of China(No.2019YFC1408100)。
文摘Erratum to:https://doi.org/10.1007/s00343-021-0384-7 The authors’affiliations of this article contain a few mistakes.The correct ones are given below:1 College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China 2 Key Laboratory of Marine Environment and Ecology,Ministry of Education of China,Ocean University of China,Qingdao 266100,China The online version of the original articles can be found at:https://doi.org/10.1007/s00343-021-0384-7.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.9215010612021004,and 11934006)the Innovation Project of Optics Valley Laboratory(No.OVL2021ZD001),the Major Program(JD)of Hubei Province(No.203BAA015)the Cross Research Support Program of Huazhong University of Science and Technology(No.2023JCYJ041).
文摘An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching approximately 233 W.The active-locking of these coherently combined channels,followed by compression using gratings,yields an output with a pulse energy of 504μJ and an average power of 403 W.Exceptional stability is maintained,with a 0.3%root mean square(RMS)deviation and a beam quality factor M^(2)<1.2.Notably,precise dispersion management of the front-end seed light effectively compensates for the accumulated high-order dispersion in subsequent amplification stages.This strategic approach results in a significant reduction in the final output pulse duration for the coherently combined laser beam,reducing it from 488 to 260 fs after the gratings compressor,while concurrently enhancing the energy of the primary peak from 65%to 92%.
基金supportedby the National Natural Science Foundation of China(Grant No.11875140),Science and Technology on Plasma Physics Laboratory(Grant No.6142A04200212)Innovation Project of Optics Valley Laboratory(Grant No.OVL2021ZD001),and Innovation Fund of WNLO.
文摘Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions,allows one to predict and understand the underlying physics of light interaction with matter,whose spatially resolved transient dielectric function experiences ultrafast evolution.However,such a task is technically challenging for two reasons:first,one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional(2D)detector;second,typical detectors are only sensitive to intensity or amplitude information rather than phase.Here we have demonstrated compressed optical field topography(COFT)drawing a 3D map for an ultrafast optical field in single-shot,by combining the coded aperture snapshot spectral imaging(CASSI)technique with a global 3D phase retrieval procedure.COFT can,in single-shot,fully characterize the spatiotemporal coupling of a femtosecond laser pulse,and live stream the light-speed propagation of an air plasma ionization front,unveiling its potential applications in ultrafast sciences.
基金This work was supported by grants to W.L.from the National Natural Science Foundation of China(31730107,31970959,31671056).
文摘Background:βAmyloid(Aβ)-mediated neuronal hyperactivity,a key feature of the early stage of Alzheimer’s disease(AD),is recently proposed to be initiated by the suppression of glutamate reuptake.Nevertheless,the underlying mechanism by which the impaired glutamate reuptake causes neuronal hyperactivity remains unclear.Chronic suppression of the glutamate reuptake causes accumulation of ambient glutamate that could difuse from synaptic sites at the dendrites to the soma to elevate the tonic activation of somatic N-methyl-D-aspartate receptors(NMDARs).However,less attention has been paid to the potential role of tonic activity change in extrasynaptic glutamate receptors(GluRs)located at the neuronal soma on generation of neuronal hyperactivity.Methods:Whole-cell patch-clamp recordings were performed on CA1 pyramidal neurons in acute hippocampal slices exposed to TFB-threo-β-benzyloxyaspartic acid(TBOA)or human Aβ_(1-42) peptide oligomer.A series of dendritic patch-clamp recordings were made at diferent distances from the soma to identify the location of the changes in synaptic inputs.Moreover,single-channel recording in the cell-attached mode was performed to investigate the activity changes of single NMDARs at the soma.Results:Blocking glutamate uptake with either TBOA or the human Aβ_(1-42) peptide oligomer elicited potentiation of synaptic inputs in CA1 hippocampal neurons.Strikingly,this potentiation specifcally occurred at the soma,depending on the activation of somatic GluN2B-containing NMDARs(GluN2B-NMDARs)and accompanied by a substantial and persistent increment in the open probability of somatic NMDARs.Blocking the activity of GluN2B-NMDARs at the soma completely reversed both the TBOA-induced or the Aβ_(1-42)-induced somatic potentiation and neuronal hyperactivity.Conclusions:The somatic potentiation of synaptic inputs may represent a novel amplifcation mechanism that elevates cell excitability and thus contributes to neuronal hyperactivity initiated by impaired glutamate reuptake in AD.
