The emerging two-terminal memristor with a conductance-adjustable function under external stimulation is considered a strong candidate for use in artificial memory and electronic synapses. However, the stability, unif...The emerging two-terminal memristor with a conductance-adjustable function under external stimulation is considered a strong candidate for use in artificial memory and electronic synapses. However, the stability, uniformity, and power consumption of memristors are still challenging in neuromorphic computing. Here an Au/SnSe/graphene/SiO_(2)/Si memristor was fabricated, incorporating two-dimensional graphene with high thermal conductivity. The device not only exhibits excellent electrical characteristics(e.g., high stability,good uniformity and a high ROFF/RON ratio), but also can implement biological synaptic functions such as paired-pulse facilitation, short-term plasticity and long-term plasticity. Its set and reset power values can be as low as 16.7 and 2.3 nW,respectively. Meanwhile, the resistance switching mechanism for the device, which might be associated with the formation and rupture of a filamentary conducting path consisting of Sn vacancies, was confirmed by high-resolution transmission electron microscopy observations. The proposed device is an excellent candidate for use in high-density storage and lowpower neuromorphic computing applications.展开更多
The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer’s disease(AD) and amnestic mild cognitive impairment(aMCI) based on a triple network mod...The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer’s disease(AD) and amnestic mild cognitive impairment(aMCI) based on a triple network model consisting of the default mode network(DMN), salience network(SN), and executive control network(ECN). The technique of voxel-mirrored homotopic connectivity(VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that:(1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions(i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions(i.e. frontoinsular cortex), and ECN-related brain regions(i.e. frontal middle gyrus and frontal inferior);(2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control(HC) groups, but no significant difference was observed between the a MCI and HC groups; and(3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination(MMSE) and Montreal Cognitive Scale(MOCA) scores and their factor scores in the AD, a MCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the a MCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.展开更多
基金financially supported by the National Natural Science Foundation of China (51972094,61674050 and 61874158)the Outstanding Youth Project of Hebei Province (F2016201220)+3 种基金the Project of Science and Technology Activities for Overseas Researcher (CL201602)the Project of Distinguished Youth of Hebei Province (A2018201231)the Support Program for the Top Young Talents of Hebei Province (70280011807)the Supporting Plan for 100 Excellent Innovative Talents in Colleges and Universities of Hebei Province (SLRC2019018)。
文摘The emerging two-terminal memristor with a conductance-adjustable function under external stimulation is considered a strong candidate for use in artificial memory and electronic synapses. However, the stability, uniformity, and power consumption of memristors are still challenging in neuromorphic computing. Here an Au/SnSe/graphene/SiO_(2)/Si memristor was fabricated, incorporating two-dimensional graphene with high thermal conductivity. The device not only exhibits excellent electrical characteristics(e.g., high stability,good uniformity and a high ROFF/RON ratio), but also can implement biological synaptic functions such as paired-pulse facilitation, short-term plasticity and long-term plasticity. Its set and reset power values can be as low as 16.7 and 2.3 nW,respectively. Meanwhile, the resistance switching mechanism for the device, which might be associated with the formation and rupture of a filamentary conducting path consisting of Sn vacancies, was confirmed by high-resolution transmission electron microscopy observations. The proposed device is an excellent candidate for use in high-density storage and lowpower neuromorphic computing applications.
基金Project supported by the National Natural Science Foundation of China(No.81771158)the Science Foundation of the Health Commission of Zhejiang Province(Nos.2016147373 and 2019321345),China
文摘The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer’s disease(AD) and amnestic mild cognitive impairment(aMCI) based on a triple network model consisting of the default mode network(DMN), salience network(SN), and executive control network(ECN). The technique of voxel-mirrored homotopic connectivity(VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that:(1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions(i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions(i.e. frontoinsular cortex), and ECN-related brain regions(i.e. frontal middle gyrus and frontal inferior);(2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control(HC) groups, but no significant difference was observed between the a MCI and HC groups; and(3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination(MMSE) and Montreal Cognitive Scale(MOCA) scores and their factor scores in the AD, a MCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the a MCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.