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2017 Vol. 36, No. 2 Published: 2017-04-20 Reviews Communications Regular Papers        Regular Papers 129 Multi-Contrast Magnetic Resonance Imaging Registration of Carotid Arteries Wu Yuxia, Xu Xiaopan, Zhang Xi, Liu Yang, Zhang Guopeng, Chen Huijun, Lu Hongbing, Li Baojuan, DOI: 10.3969/j.issn.0258-8021.2017.02.001 Recently multi-contrast magnetic resonance imaging (MRI) has become a powerful tool for plaque analyzing due to its strong potential in enhanced demonstration of carotid wall, but its performance is hampered by the misalignment of difference imaging sequences. To achieve accurate vessel registration of multi-sequence images, a two-step coarse-to-fine registration strategy was proposed in this study. First, the iterative closest point was applied to realize the rigid registration of the centerlines of the multi-contrast images, and then the thin plate spline was used to realize the non-rigid registration based on the boundaries of carotid artery. In the second step, to find the corresponding points of the boundaries in different sequences, a shape context descriptor was innovatively introduced to screen the boundary points. In addition, the deterministic annealing technique was employed to find a globally optimized solution. The effectiveness of the proposed algorithm was quantitatively evaluated by novel three-dimensional (3D) multi-contrast vessel wall MRI sequences. The results indicated that after registration, the overlap of two boundaries from different sequences was more than 95%, and their mean surface distance was 0.12 mm, which improved the accuracy of registration effectively and laid the foundation for further component analysis. 2017 Vol. 36 (2): 129-135 [Abstract] ( 622 ) HTML (1 KB)  PDF (1693 KB)  ( 372 ) 136 Global Motif-Synchronization Based Multivariate EEG Synchronization Analysis Cui Dong, Pu Weiting, Li Xiaoli, Wang Lei, Yin Shimin, Bian Zhijie, DOI: 10.3969/j.issn.0258-8021.2017.02.002 EEG synchronization is considered to be the performance of brain functional area integration. A time series motif based multi-channel synchronization method——global motif-synchronization (GMS) was proposed in this study. The simulation analysis indicated that the new algorithm was more sensitive than S-estimator based normalized weighted permutation mutual information in detection weak coupling. The algorithm was used to analyze the EEG synchronization of 26 amnesic MCI and 20 normal controls of patients with diabetes in eye-closed resting state. The wavelet enhanced independent component analysis was used to eliminate artifacts. The 32-channels EEG was divided to frontal, central, parietal, occipital, left temporal and right temporal region respectively. The independent samples t-test was performed to test differences in demographic characteristics, neuropsychology and regional synchronization values between two groups. The Pearson’s linear correlation was used to study the associations between regional synchronization values and cognitive functions. The results showed that GMS values in each brain region of diabetes patients with MCI were lower than that of control group. Especially, the GMS values decreased significantly in central (P<0.01), parietal (P<0.05) and occipital (P<0.05) regions. The MOCA scores and GMS value had a significant positive correlation in frontal (r=0.298, P=0.045), central (r=0.327, P=0.026) and parietal (r=0.32, P=0.03) regions. The GMS is an important EEG characteristic that is correlated with cognitive function impairment. 2017 Vol. 36 (2): 136-142 [Abstract] ( 449 ) HTML (1 KB)  PDF (1002 KB)  ( 364 ) 143 A Specific EEG Network Structure Related to Mental Fatigue Induced by N-back Meng Guifang, Xu Minpeng, Zhang Chuncui, He Feng, Qi Hongzhi, Ming Dong DOI: 10.3969/j.issn.0258-8021.2017.02.003 The aim of this study was to investigate the changes of resting state EEG network structure caused by mental fatigue, and the influence of physical fatigue on the mental fatigue-related EEG network. Two-back task and cycling were used to induce mental fatigue and physical fatigue, respectively. Twenty channels of resting state EEG of 10 subjects were collected under 4 different fatigue conditions. EEG networks were obtained by calculating the partial directed coherence (PDC) causality between two arbitrary nodes and refined by comparing to a threshold. Only those links significantly higher than the threshold would be reserved, while others dismissed. After a comparison among the four EEG networks, a mental fatigue-related specific EEG network structure in N-back experiments was identified, in which FP2 was the hub while almost other channels had a link with it. The network structure was very stable, and its corresponding linking strength 4.0603 and 4.1421 in two fatigue state, which would not be influenced by physical fatigue. Therefore, this study identified an independent and stable functional network related to mental fatigue. The result provided a new perspective on the neural mechanism of mental fatigue and the relationship between mental fatigue and physical fatigue. 2017 Vol. 36 (2): 143-149 [Abstract] ( 447 ) HTML (1 KB)  PDF (2736 KB)  ( 427 ) 150 Research on the Intermuscular Synergy and Coupling Analysis Based on Surface EMG Nonnegative Matrix Factorization-Coherence Xie Ping, Li Xinxin, Yang Chunhua, Yang Fangmei, Chen Xiaoling, Wu Xiaoguang DOI: 10.3969/j.issn.0258-8021.2017.02.004 The muscle synergy model is a low-dimensional structure in which nerves produce and control motion. The aim of this work was to study whether the coherence of surface electromyography could reflect the synergy-coupling relationship of the muscle groups under different movements and reveal the laws of movement generation and execution from the point of neural control and muscle coordination. In this study, we chose eight young healthy subjects (4 men and 4 women, 20～24 years old) to perform the upper limb wrist flexion and extension experiments, the sEMG data from different muscle groups were collected during the action. This study analyzed synergy between muscles bynonnegative matrix factorization. The coherence analysis method was used to study intermuscular coupling relationship in the beta (15~35 Hz) and gamma (35~60 Hz) band with the signals of high synergy muscles, and the differences of synergy-coupling between different subjects under wrist flexion and extension were investigated. Results showed that active muscles of extensor carpi radialis (ECR), extensor digitorum (ED), extensor carpi ulnaris (ECU) and brachioradialis (B) had synergistic relationship in synergy model W5 under the wrist extension movement, the intensity of intermuscular coupling was significantly different (P<0.05), and there was a significant difference in the value of coherence area between beta and gamma band (1.261±0.966). In the wrist flexion movement, intermuscular synergy appeared in synergy models W1 W4 W5, the intensity of intermuscular coupling was significantly different (P<0.001), and there was a nuance in the value of coherence area between beta and gamma band (0.412±0.163), active muscles of flexor carpi radialis (FCR) and flexor digitorum superficialis (FDS) had no synergistic relationship, the intermuscular coupling relationship was small. Taken above together, there were differences in the neural control action, which showed the different intermuscular synergy-coupling relationship. In the same synergy model, the intermuscular coupling relationship with high synergism was stronger. It revealed the law of the neural control action and muscle interaction with each other. The proposed method was expected to be applied in the future to reveal the central nervous system of modular synergistic control mechanism of movement, and to provide scientific basis for functional analysis and evaluation of patients with movement disorders. 2017 Vol. 36 (2): 150-157 [Abstract] ( 548 ) HTML (1 KB)  PDF (2494 KB)  ( 556 ) 158 Implementation of the Algorithm for Premature Ventricular Contraction Discrimination Based on Extreme Learning Machine Wang Ruirong, Yu Xiaoqing, Wang Min, Ye Yang DOI: 10.3969/j.issn.0258-8021.2017.02.005 Premature ventricular contraction (PVC) is a common heart rhythm disorders, which threatens humanity’s health, therefore accurate diagnosis of abnormal heart rhythms plays an important role to help humanity prevent cardiovascular disease. This paper proposed a diagnosis method based on ELM (extreme learning machine, ELM) to realize the discrimination of PVC from normal ECG (electrocardiograph) using the data from the MIT-BIH database as analysis object, and process of the method includes signal preprocessing, feature extraction and classification. The first step was to apply the wavelet transform combined with morphological filtering method for signal preprocessing to get the relatively clean signal, Then extracted feature parameters of QRS complex by using K-means clustering algorithm. Meanwhile, the calibration samples and prediction samples were established according to the feature parameters, and finally the ELM classifier for sample training match and classification recognition was adopted. 1260 cycles of signal were chosen to do experiment, and the results demonstrated that this algorithm could accurately diagnose the PVC, whose positive detection rate was up to 95% and sensitivity was up to 96% on average. Compared with other algorithms in the condition of similar detection accuracy, this algorithm can improve the real-time performance of the algorithm, which has high research value and certain practical value in mobile medical treatment and clinical medical treatment. 2017 Vol. 36 (2): 158-164 [Abstract] ( 400 ) HTML (1 KB)  PDF (3153 KB)  ( 547 ) 165 A Detection Method for the Fall Behavior of Elders Based on Hidden Markov Model Cao Huiqiang, Lin Chungchih, Wu Shuicai DOI: 10.3969/j.issn.0258-8021.2017.02.006 As the social aging process quickened, the demand to care the elderly's health and safety is increasing. The fall in the elderly population is a very common phenomenon; it has been a major health risk that diminishes the quality of life among the elderly people. In this paper, we proposed a new method using acceleration observation series to build a hidden Markov model (HMM)to detect the fall behavior. The method extracted acceleration characteristic time series from human fall course to describe the fall process, and used the acceleration characteristic time series to train HMM in order to build a random process mathematical model. The 300 samples of experimental data from 10 volunteers were obtained, and 5-fold cross-validation was used to estimate the model. Results showed that the accuracy of the method was 98.2%, the sensitivity was 91.3%, and the specificity was 99.6%, showing that the proposed method gets good result in detecting fall events. 2017 Vol. 36 (2): 165-171 [Abstract] ( 445 ) HTML (1 KB)  PDF (2925 KB)  ( 446 ) 172 Experimental Study on in vivo Impedance Spectrums of Mice's Back Skin Li Ying, Song Bing, Liu Zhipeng, Yin Tao DOI: 10.3969/j.issn.0258-8021.2017.02.007 Different from other tissues, it is difficult to study the impedance of stratum corneum regarding skin as a whole subject, due to its huge impedance. The aim of this work is to non-invasively examine the characteristics of the impedance of mice’s back skin including stratum corneum in vivo. Using Agilent 4294A impedance analyzer, impedance spectrums of the back skin of 15 C57BL/6 mice under anesthesia were measured, and surface electrodes and acupuncture needles were used to record data as the whole skin and viable skin respectively. Along with the increase of frequency, the amplitude of impedance of the whole skin declined at the rate of -20 dB/dec within all the frequency span from 40 Hz to 107 Hz; whereas that of the viable skin decreased at -10 dB/dec in the range of 40 Hz to103 Hz, and at -3 dB/dec in the range of 103 Hz to 107 Hz. The phase of the whole skin decreased and then increased in a V-shape curve, and that of viable skin varied as a Π-shape curve. At low frequencies, such as 100 Hz, the whole skin impedance can be regarded as only consisting of the impedance of stratum corneum, and the viable skin part can be omitted. At medium frequencies, such as 105 Hz, the viable skin contributes over 10% to the whole skin impedance. However, at high frequencies, such as 107 Hz, the viable skin contributed over 80% to the whole skin impedance. The impedance of the whole skin and viable skin showed significant difference below 103 Hz (P<0.05) and no significant difference over 104 Hz. The results showed that this novel method that comparing the impedance recorded by surface electrodes and acupuncture needles was effective in the analysis of the impedance of stratum corneum within the whole skin impedance. 2017 Vol. 36 (2): 172-179 [Abstract] ( 505 ) HTML (1 KB)  PDF (2106 KB)  ( 532 ) 180 Research of p53-Mdm2 Regulatory Networks Based on Modeling by Continuous-Discrete Extended Kalman Filter Jiang Li, Li Yurong DOI: 10.3969/j.issn.0258-8021.2017.02.008 The studies of biomedicine show that the expression level of p53 (tumor suppressor gene) is related with the tumor forming. Researches of the p53 related signal transduction networks would provide new ideas for revealing the pathogenesis of cancer or tumor and looking for the treatment method. As the p53-Mdm2 negative feedback network plays core roles, the study of the p53-Mdm2 regulation net work is of great significance. In this paper, based on the gene expression time series data of human leukemia cells after ionizing radiation, the nonlinear dynamic continuous random biological networks with time delay were established, then continuous-discrete extended Kalman filter (EKF) algorithm was used to simulate the dynamic regulation of p53 and Mdm2. Meanwhile, the accuracy of the model established in this paper was validated and we found that the error rate of the model was only 0.85%. Results showed that the algorithm thatis convergent could predict gene expression level at any time and simulate accurately the damped oscillation process of p53-Mdm2 regulatory networks after ionizing radiation. The response process was consistent with biological experiment results. The algorithm proposed in this paper provided an effective method for biological experiment modeling, and supplied the foundation for the research of system dynamics. 2017 Vol. 36 (2): 180-186 [Abstract] ( 338 ) HTML (1 KB)  PDF (914 KB)  ( 282 ) 187 Design of the Portable Potentiostat for the Detection of Trace Level of Vitamin B2 Xu Ying, Luo Yulin, Guo Miao DOI: 10.3969/j.issn.0258-8021.2017.02.009 This paper introduced a portable potentiostat platform based on AVR microcontroller, which was used for electrochemical detection of trace vitamin B2. The platform adopted the high-precise conversion chip AD7705 and DAC8831 and used a microcontroller ATmega16 as a controlling core. The integrated operational amplifier was designed by OPA211 as the core device. The software design adopted optimized calibration logic. Therefore, the potentiostat output was effectively controlled, and the functions of setting the potentiostatic and measuring the polarization current parameter were implemented. Testing results showed that the potentiostat potential error was controlled within the millivolt, the maximum error was about 1%, and the test current limit value was less than 1 μA. The stability and sensitivity of the portable potentiostat platform was also analyzed compared with the CHI660C electrochemical instrument. The linearity between the peak current and the concentration of vitamin B2 was measured by the platform experiment, and the correlation coefficient was 0.994. The rapid detection of vitamin B2 in food was preliminarily verified. 2017 Vol. 36 (2): 187-194 [Abstract] ( 340 ) HTML (1 KB)  PDF (2046 KB)  ( 296 ) 195 Study on FE Modeling Method of the 50th Percentile Chinese Shank with Optimization Methods under Multi-Loading Condition Zhang Guanjun, Wang Longliang, Deng Xiaopeng, Du Xianping, Guan Fengjiao DOI: 10.3969/j.issn.0258-8021.2017.02.010 The lower extremity of the human body is one of the most vulnerable parts in traffic accidents, and the finite element (FE) model of the lower limb has become an important tool to study mechanisms and protective methods of lower limb injuries. In order to ensure the fidelity of the model, it is necessary to carry out a comprehensive validation under multi-loading conditions. The biomechanical test data are different in the mechanical response due to the sample size and material diversity, so it is difficult to use one model to meet the multiple test data. The differences in geometric dimensions between Chinese and occidental human body would result in differences of biomechanical response, so it is necessary to develop the FE model of Chinese human body. In this paper, Geometry model based on the CT and MRI data was scaled to the 50 percentile male according to scaling factor derived from key dimensions of the tibia. The scaling method was also used to scale biomechanical test data to the biomechanical response data corresponding to the size of the leg. The elastic modulus, stress-strain curve, failure strain of the tibia and fibula and physical bulk modulus of the muscle were selected as design variables, the optimization method was used to fit tibia, fibula and calf biomechanical responses under different load positions in the quasi-static and dynamic loading conditions, which solved the problem with diversity caused by the test sample. When the elastic modulus of tibia and fibula were 18.43 and 18.23GPa, respectively, the failure strains were 1.156% and 0.8%, respectively, and physical bulk modulus of the calf was 11.33MPa, the calf model could fit the biomechanical responses well in many groups of tests. The FE model verification methods based on the optimization of multi-loading conditionsmade the FE model acquire better biofidelity effectively. 2017 Vol. 36 (2): 195-204 [Abstract] ( 392 ) HTML (1 KB)  PDF (5045 KB)  ( 468 ) 205 The Cytocompatibility of Ctenopharyngodon Idellus Fishskin Collagen with NIH3T3 Fibroblasts Yu Lan, Wang Haibo, Chen Zhuo, Fang Cheng DOI: 10.3969/j.issn.0258-8021.2017.02.011 This study is aimed to test the cytocompatibility of fishskin acid-soluble collagen (FASC) of ctenopharyngodon idellus in vitro. The proliferation rates of NIH3T3 fibroblasts were detected using different concentrations of FASC solutions or coating gums by MTT experiment (n=6). The chemotaxis of fibroblasts towards FASC solutions were tested by chemotactic experiments of transwell (n=3). The cellular permeabilities in different concentrations of FASC coating gums were detected by invasive experiments of transwell (n=3). FASC solutions promote proliferation of NIH3T3 fibroblasts and the growth activity of the fibroblasts was dose-dependent on FASC. The proliferation rates of 16 μg/mL FASC solution in 48 and 96 h were (63.7±7.9)% and (87.3±8.7)%, that showed significant differences compared with the control group (P<0.001). NIH3T3 fibroblasts grew on FASC coating gums without significant differences compared with the control group (P>0.05). The chemotatic indexes showed significant differences between the concentration gradient groups of FASC solutions and the control group(P<0.05), which indicated that FASC has chemotaxis to fibroblasts. Invasion experiments showed fibroblasts could pass through FASC coating gums. These experiments confirmed that FASC possesses favourable cytocompatibility with NIH3T3 fibroblasts. 2017 Vol. 36 (2): 205-210 [Abstract] ( 356 ) HTML (1 KB)  PDF (7995 KB)  ( 275 )        Reviews 211 A Review of Gene and Isoform Expression Analysis across Multiple Experimental Platforms Wang Kaili, Zhang Li, Liu Xuejun DOI: 10.3969/j.issn.0258-8021.2017.02.012 Transcriptomics study has become a hot topic in life science and medical research in recent years. From the expression point of view, the foundation of transcriptomics study is the measurement of gene expression levels. Differential expression (DE) analysis of genes is very important for understanding the function of genes. DE analysis of isoforms is a feasible method to reflect the change of alternative splicing. Currently, there are mainly two large-scale experimental platforms for measuring gene expression levels, including microarray and high-throughput sequencing technology, RNA-Seq. At the beginning of this paper, we introduced the technical principles of the four mainstream experimental platforms: Affymetrix's traditional 3' GeneChip, Exon array, Human Transcriptome Array 2.0 and Illumina platform based on RNA-Seq. We then reviewed the mainstream analysis methods and our methods on each platform for the calculation of gene expression levels and DE analysis. We also showed the comparison results of expression measurement and DE analysis across various platforms under a well-defined benchmark data set. 2017 Vol. 36 (2): 211-218 [Abstract] ( 373 ) HTML (1 KB)  PDF (993 KB)  ( 395 ) 219 Progress in the Preparation of Fluorescence-Encoded Microspheres Li Yan, Luo Cheng, Wu Daocheng DOI: 10.3969/j.issn.0258-8021.2017.02.013 Suspension array is a promising platform for multiplex analyses with broad applications in science research and clinical diagnosis. As one of the key components for the suspension array, fluorescence-encoded microspheres have received much attention and a lot of achievements have been made. In this review, the analysis pattern and applications of suspension array were introduced, and recent advances in the fluorescence-encoded microspheres were summarized according to the classification of preparationmethods including swelling method, layer-by-layer (LBL) self-assembly, embedding in microspheres, microfluidic techniques and membrane emulsification. Current challenges and future directions of fluorescence-encoded microspheres were also outlined. 2017 Vol. 36 (2): 219-227 [Abstract] ( 658 ) HTML (1 KB)  PDF (4126 KB)  ( 1542 )        Communications 228 Research on Cerebral Structural Network of Brain Tumor Patients before and after Surgery Xue Li Tao Ling, Qian Zhiyu, Yu Zhou, Sun Jinyang DOI: 10.3969/j.issn.0258-8021.2017.02.014 2017 Vol. 36 (2): 228-232 [Abstract] ( 408 ) HTML (1 KB)  PDF (983 KB)  ( 455 ) 233 Study on Gait Characteristics of Lower Extremities Surface Electromyography after Slips and Falls Su Hailong, Xu Zhaojian, Zhang Junxia, Zhang Yan DOI: 10.3969/j.issn.0258-8021.2017.02.015 2017 Vol. 36 (2): 233-237 [Abstract] ( 335 ) HTML (1 KB)  PDF (3657 KB)  ( 378 ) 238 Design and Experimental Research of Multi-ChannelSacral Anterior Root Stimulation System for Bladder Function Rebuilding Wang Lei, Wang Shuhong, Lv Xiaoying, Wang Zhigong DOI: 10.3969/j.issn.0258-8021.2017.02.016 2017 Vol. 36 (2): 238-242 [Abstract] ( 359 ) HTML (1 KB)  PDF (4012 KB)  ( 245 ) 243 Experimental Study on Photodynamic Therapy of Massive Trauma Rats Zhao Zhanjuan, Li Shijie, Xu Zehua, Shang Yazhen, Liu Tianjun DOI: 10.3969/j.issn.0258-8021.2017.02.017 2017 Vol. 36 (2): 243-247 [Abstract] ( 279 ) HTML (1 KB)  PDF (922 KB)  ( 363 ) 248 Applications of Cellular Automata to Simulate Cell Behavior Li Xiangyang, Sun Liang, Cui Tiantian DOI: 10.3969/j.issn.0258-8021.2017.02.018 2017 Vol. 36 (2): 248-251 [Abstract] ( 415 ) HTML (1 KB)  PDF (741 KB)  ( 395 ) 252 The Preparation and Properties Study on Fabrics of Stent-Graft with Local Durable Structures Du Jia, Lin Jing, Guidoin Robert, Zang Jingyi, Lu Jun, Zhang Fuhu, Lao Jihong, Wang Lu DOI: 10.3969/j.issn.0258-8021.2017.02.019 2017 Vol. 36 (2): 252-253 [Abstract] ( 388 ) HTML (1 KB)  PDF (4319 KB)  ( 504 )

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