Electroencephalogram (EEG) is the primary tool in investigation of the brain science. It is necessary to carry out a deepgoing study into the characteristics and information hidden in EEGs to meet the needs of the clinical research. In this paper, we present a wavelet-nonlinear dynamic methodology for analysis of nonlinear characteristic of EEGs and delta, theta, alpha, and beta sub-bands. We therefore studied the effectiveness of correlation dimension (CD), largest Lyapunov exponen, and approximate entropy (ApEn) in differentiation between the interictal EEG and ictal EEG based on statistical significance of the differences. The results showed that the nonlinear dynamic characteristic of EEG and EEG subbands could be used as effective identification statistics in detecting seizures.
Biological neural networks have dual properties of small-world attributes and scale-free attributes. Most of the current researches on neural networks are based on small-world networks or scale-free networks with lower clustering coefficient, however, the real brain network is a scale-free network with small-world attributes. In this paper, a scale-free spiking neural network with high clustering coefficient and small-world attribute was constructed. The dynamic evolution process was analyzed from three aspects: synaptic regulation process, firing characteristics and complex network characteristics. The experimental results show that, as time goes by, the synaptic strength gradually decreases and tends to be stable. As a result, the connection strength of the network decreases and tends to be stable; the firing rate of neurons gradually decreases and tends to be stable, and the synchronization becomes worse; the local information transmission efficiency is stable, the global information transmission efficiency is reduced and tends to be stable, and the small-world attributes are relatively stable. The dynamic characteristics vary with time and interact with each other. The regulation of synapses is based on the firing time of neurons, and the regulation of synapses will affect the firing of neurons and complex characteristics of networks. In this paper, a scale-free spiking neural network was constructed, which has biological authenticity. It lays a foundation for the research of artificial neural network and its engineering application.
Objective To investigate the long-term dynamic changes of liver function and glucose-lipid metabolism in human immunodeficiency virus (HIV)-infected patients with metabolic dysfunction-associated fatty liver disease (MAFLD) after antiretroviral therapy (ART). Methods HIV-infected patients who visited Public Health Clinical Center of Chengdu between October 1st, 2012 and June 30th, 2013 were recruited and divided into two groups according to whether they had MAFLD or not. All of them were treated with the first-line regimen of tenofovir + lamivudine + efavirenz for 156 weeks, and the anthropometric indices, liver function, and levels of glucose, lipids and uric acid were measured at baseline and at each follow-up time point. In addition, the long-term dynamic characteristics of liver function and glucose and lipid metabolism parameters of the two groups were compared during the 156 weeks of ART treatment. Results A total of 61 male HIV-infected patients were enrolled. The prevalence of MAFLD in them was 31.1% (19/61) at baseline and increased by 4.9 percentage points per year after ART. Before the start of follow-up (week 0), the levels of alanine aminotransferase (ALT) [(46.23±27.09) vs. (28.00±17.43) U/L, P=0.002] and γ-glutamyl transpeptidase (GGT) [(41.46±9.89) vs. (24.02±10.72) U/L, P<0.001] were higher in the MAFLD group than those in the non-MAFLD group, while the between-group differences in the levels of aspartate aminotransferase (AST) [(33.33±15.61) vs. (28.98±12.43) U/L, P=0.248] and alkaline phosphatase [(85.30±21.27) vs. (83.41±24.47) U/L, P=0.773] were not statistically significant. During the 156-week follow-up period, the 4 items of liver function gradually increased in the MAFLD group, especially from week 120 onwards, 3 of which (ALT, AST and GGT) were significantly higher than those in the non-MAFLD group (P<0.05). In addition, the levels of fasting blood glucose, triglyceride, total cholesterol, and low-density lipoprotein were also significantly higher in the MAFLD group than those in the non-MAFLD group at some time points during the 156-week follow-up period (P<0.05). Conclusions Compared with HIV-infected patients without MAFLD, HIV-infected patients with MAFLD are more likely to develop impaired liver function and disorders of glucose and lipid metabolism during long-term tenofovir + lamivudine + efavirenz regimen ART treatment. Therefore, close clinical monitoring of liver function and glucose and lipid metabolism related parameters is required for such patients.