大脑前额叶皮层自发活动与连接的性别差异

Functional near-infrared spectroscopy (fNIRS) is a non-invasive optical technique for brain functional imaging. The objective of this study is using fNIRS to investigate sex-related differences in the spatial distribution of spontaneous hemodynamic fluctuations and resting-state functional connectivity (RSFC) in the prefrontal cortex. 20 heathy young adults participated in the experiment. 42 optical channels covered the anterior prefrontal cortex (aPFC), dorsolateral prefrontal cortex (DLPFC) and the language area (inferior frontal gyrus (IFG) and superior temporal gyrus (STG)). 8-min spontaneous hemodynamic fluctuations were recorded from each subject. The spatial distribution of the fluctuation power was calculated for each sex. To quantitatively characterize the degree of RSFC, the temporal correlation coefficients of the fluctuations were computed for all optical channel pairs. Two distinct networks were identified. One involved the aPFC and DLPFC, and the other included the bilateral language areas. Sex-related differences in the spatial distribution of the fluctuation power and RSFC were revealed. Compared with females, males experienced higher power of the fluctuations, especially in the aPFC+DLPFC. Males showed larger intra-network connectivity in the aPFC+DLPFC, whereas females showed larger inter-network connectivity between the language area and aPFC+DLPFC. Our observations might provide functional imaging-based evidence for understanding sex-related differences in behaviors and cognitions.     

基于单元应变模态差和RBF神经网络的网架损伤检测方法

为对网架进行损伤检测提出应用杆单元应变模态差和RBF神经网络相结合的方法。在ANSYS下建立正放四角锥网架和蜂窝形三角锥网架的有限元模型,采用单元应变模态差作为损伤指标对结构进行杆单元的单杆、多杆损伤位置识别;应用RBF神经网络对杆单元损伤程度进行定量判定。分析结果表明该方法可以比较准确地判断网架杆单元的损伤位置和损伤程度,并对实际网架结构的损伤检测具有一定的指导意义。