1.Automatic epileptic seizure detection algorithm based on dual density dual tree complex wavelet transform.
Tongzhou KANG ; Rundong ZUO ; Lanfeng ZHONG ; Wenjing CHEN ; Heng ZHANG ; Hongxiu LIU ; Dakun LAI
Journal of Biomedical Engineering 2021;38(6):1035-1042
		                        		
		                        			
		                        			It is very important for epilepsy treatment to distinguish epileptic seizure and non-seizure. In this study, an automatic seizure detection algorithm based on dual density dual tree complex wavelet transform (DD-DT CWT) for intracranial electroencephalogram (iEEG) was proposed. The experimental data were collected from 15 719 competition data set up by the National Institutes of Health (NINDS) in Kaggle. The processed database consisted of 55 023 seizure epochs and 501 990 non-seizure epochs. Each epoch was 1 second long and contained 174 sampling points. Firstly, the signal was resampled. Then, DD-DT CWT was used for EEG signal processing. Four kinds of features include wavelet entropy, variance, energy and mean value were extracted from the signal. Finally, these features were sent to least squares-support vector machine (LS-SVM) for learning and classification. The appropriate decomposition level was selected by comparing the experimental results under different wavelet decomposition levels. The experimental results showed that the features selected in this paper were different between seizure and non-seizure. Among the eight patients, the average accuracy of three-level decomposition classification was 91.98%, the sensitivity was 90.15%, and the specificity was 93.81%. The work of this paper shows that our algorithm has excellent performance in the two classification of EEG signals of epileptic patients, and can detect the seizure period automatically and efficiently.
		                        		
		                        		
		                        		
		                        			Algorithms
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		                        			Electroencephalography
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		                        			Epilepsy/diagnosis*
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		                        			Humans
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		                        			Seizures/diagnosis*
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		                        			Signal Processing, Computer-Assisted
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		                        			Support Vector Machine
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		                        			Wavelet Analysis
		                        			
		                        		
		                        	
2.Clinical value of acoustic radiation force impulse elastography in predicting esophageal variceal bleeding in liver cirrhosis
Dakun ZHANG ; Min CHEN ; Wenhui ZHANG
Journal of Clinical Hepatology 2020;36(3):561-564
		                        		
		                        			
		                        			 ObjectiveTo investigate the clinical value of acoustic radiation force impulse (ARFI) elastography in predicting esophageal variceal bleeding in patients with liver cirrhosis. MethodsA retrospective analysis was performed for the clinical data of 271 patients with liver cirrhosis who attended the Fifth Medical Center of Chinese PLA General Hospital from October 2014 to May 2017, and ARFI elastography was performed for all patients to measure the elasticity of the liver and the spleen. According to the presence or absence of esophageal variceal bleeding, the patients were divided into bleeding group and non-bleeding group, and related indices were compared between the two groups. The receiver operating characteristic (ROC) curve was used to evaluate the value of ARFI elasticity in the diagnosis of esophageal variceal bleeding in liver cirrhosis. The t-test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between two groups. ResultsThe bleeding group had a significantly higher ARFI elasticity of the spleen than the non-bleeding group [3.89(349-4.11) m/s vs 3.46(2.93-3.80) m/s, Z=-4.941, P<0.001], and there was no significant difference in the ARFI elasticity of the liver between the bleeding group and the non-bleeding group [2.08 (1.57-2.74) m/s vs 1.98 (1.49-2.70) m/s, Z=-1.025, P=0.305]. The areas under the ROC curve for ARFI elasticity values of the spleen and the liver were 0.714 and 0.544, respectively, in predicting esophageal variceal bleeding in patients with liver cirrhosis (P=0.002 5). At the cut-off value of 3.71 m/s, the ARFI elasticity of the spleen had a sensitivity of 0.68 and a specificity of 0.69 in predicting esophageal variceal bleeding. ConclusionThe ARFI elasticity value of the spleen has a better value than that of the liver in predicting the risk of esophageal variceal bleeding and thus holds promise for clinical application. 
		                        		
		                        		
		                        		
		                        	
3.Diagnostic value of acoustic radiation force impulse imaging for evaluating the degree of liver fibrosis in chronic hepatitis B
Min CHEN ; Dakun ZHANG ; Yang LIU ; Ruifang WANG ; Xiaoyu DONG ; Zhiyan LI
Chinese Journal of Ultrasonography 2015;(4):311-315
		                        		
		                        			
		                        			Objective To investigate the clinical value of the acoustic radiation force impulse imaging (ARFI) in the quantitative evaluation of fibrosis staging in chronic hepatitis B .Methods A total of 373 patients with chronic hepatitis B were grouped in accordance with the depth of the right anterior lobe and posterior lobe of the liver and underwent ARFI to measure ARFI values .Liver biopsy was performed in all patients to investigate the relationship between liver fibrosis stages and ARFI values in different groups . Results The ARFI values in different pathological grades with the same depth of the right anterior and right posterior lobe of the liver were statistically significant ( P < 0 0.01);the ARFI values between the middle and deep parts of the right anterior lobe and the same location of the right posterior lobe were statistically significant ( P <0 0.1);for the right anterior lobe ,the ARFI value of the shallow part showed statistical significance from that of the middle and the deep part ( P < 0 0.5 ) .Receiver operating characteristic (ROC) curve analysis for different sampling locations showed that the largest area under the ROC curve ,which was 0 8.18 ,existed in the middle part of the right anterior lobe ,indicating that it could be the optimal sampling location for the measurement of ARFI values .Liver stiffness at ARFI imaging was significantly correlated with liver fibrosis stage in chronic hepatitis B and spearman coefficient of correlation was 0 5.30 ( P <0 0.01) .The areas under the ROC curves for the chronic hepatitis B patients with severe liver fibrosis (≥ S3) and early cirrhosis (= S4) were 0 8.18 and 0 8.60 ,respectively .Conclusions ARFI imaging was promising for clinical application and could be utilized as a noninvasive method for the quantitative evaluation of fibrosis staging in chronic hepatitis B .
		                        		
		                        		
		                        		
		                        	
4.Effect of peroxisome proliferator-activated receptor-γ on endothelial cells oxidative stress induced by Porphyromonas gingivalis
Peng LI ; Meng WAN ; Jianru LIU ; Liangzhong LI ; Dakun ZHANG
Journal of Peking University(Health Sciences) 2015;47(6):977-982
		                        		
		                        			
		                        			Objective:To detect the degree of oxidative stress in the process when Porphyromonas gin-givalis ( P. gingivalis) stimulates human vascular endothelium, And to investigate the effect of peroxi-some proliferator-activated receptor(PPAR)γ on oxidative stress during this process. Methods:Human vascular endothelial cells ( HVECs) line EA. hy926 ( American Type Culture Collection ,United States) was cultured in high glucose Dulbecco' s modified eagle medium ( DMEM) . Four groups were designed:control group, P. gingivalis infected group, PPARγactivated group and PPARγblocked group. In con-trol group HVECs were cultured with only DMEM. In P. gingivalis infected group, HVECs were time-dependently stimulated by P. gingivalis W83 from 0 to 12 h. In PPARγ activated group or PPARγblocked group, PPARγ was pre-activated or blocked by a representative PPARγ agonist(15d-PGJ2 10μmol/L) or antagonist ( GW966210μmol/L) 30 minutes before the cells were stimulated by P. gingiva-lis. At 0, 0. 5, 1, 1. 5, 2, 4, 8, and 12 h, the culture medium was collected individually and centri-fuged, and the supernatant was stored for assay. Glutathione peroxidase (GSH-PX) and malondialdehyde( MDA) were analysed by enzyme-linked immunosorbent assay. Cellular reactive oxygen species ( ROS) were detected through 2',7'-dichlorofluorescin diacetate (DCFA-DA) fluorescent probe at various time points of the different groups. Results:In P. gingivalis infected group, the levels of GSH-PX [(5. 56 ± 0. 97) μmol/L] and MDA [(0. 84 ± 0. 18) nmol/L] were significantly higher than those in control group [GSH-PX(4. 71 ± 0. 64) μmol/L, MDA (0. 59 ± 0. 18) nmol/L)]. The levels of GSH-PX and MDA in PPARγactivated group [GSH-PX (5. 38 ± 0. 84) μmol/L, MDA (0. 84 ± 0. 22) nmol/L] and in PPARγblocked group [GSH-PX (5. 37 ± 0. 76) μmol/L, MDA (0. 85 ± 0. 14) nmol/L] were signi-ficantly higher than those in control group (P <0. 05). In the PPARγ activated group, the levels of GSH-PX at 0 . 5 and 8 h were significantly higher than those from 1 . 5 h to 4 h ( P<0 . 05 ) , while no difference was observed on the MDA levels at different time points. There was no significant difference at various time points for the levels of GSH-PX and MDA in PPARγ blocked group. The level of cellular ROS detected by DCFH-DA in P. gingivalis infected group was significantly higher than that in control group (10 108. 65 ± 1 805. 18 vs. 6 049. 06 ± 1 199. 19,P<0. 05). No difference was observed be-tween PPARγ activated group (7 120. 94 ± 1 447. 30) or PPARγblocked group (6 727. 35 ± 1 483. 68) and control group. Conclusion:Oxidative stress happens when P. gingivalis stimulates human vascular endothelium. PPARγ may involve in modulating oxidative stress during this process.
		                        		
		                        		
		                        		
		                        	
5.Contrast enhanced ultrasound features of hepatic tumors contained lipid:comparing with MRI ifndings
Yang, LIU ; Enze, QU ; Zhiyan, LI ; Yuejuan, GAO ; Min, CHEN ; Dakun, ZHANG
Chinese Journal of Medical Ultrasound (Electronic Edition) 2014;(3):29-32
		                        		
		                        			
		                        			Objective To summarize the imaging features of hepatic tumors contained lipid by contrast enhanced ultrasound (CEUS), and compare with MRI ifndings. Methods From July 2010 to December 2012, 17 patients of hepatocellular carcinoma containing lipid component in the 302nd Hospital of the People′s Liberation Army underwent dual-echo sequence MRI imaging. Fifteen patients were conifrmed by enhanced MRI and contrast-enhanced CT, while the other 2 patients were confirmed by pathology. The features of ultrasonography, CEUS and MRI were analyzed. Kappa analysis test was analyzed for the consistency of CEUS and MRI ifndings. Results In the two-dimensional ultrasound of 17 lesions, 9 were hypoechoic heterogeneous lesions, 5 were hypoechoic lesions;13 lesions with clear boundaries, 4 lesions with unclear boundaries;peripheral blood lfow signal in 5 lesions and rich blood lfow in 1 lesion were observed by color Doppler ultrasound, 11 lesions had no signiifcant blood lfow signal;15 lesions showed fast high enhancement in CEUS arterial phase, 1 lesion with synchronization enhancement, 1 lesion with mild enhancement;10 lesions showed portal clearance, 1 lesion showed an enhanced synchronization, 1 lesion with mild enhancement;16 lesions showed clearance in delay phase, 1 enhanced lesion showed isoenhancement;6 lesions presented intra-lesion or surrounding patchy, irregular non-enhancement areas. CEUS diagnostic accuracy was 82%(14/17), the diagnostic accuracy of MRI was 88%(15/17). The Kappa consistency test was 0.628, while CEUS and MRI results were in good agreement. Conclusions Performance of hepatocellular lipid-containing ultrasound contrast arterial phase shows non-enhancement areas. Contrast enhanced ultrasound features of lipid-containing hepatocellular carcinoma are valuable for the clinical diagnois.
		                        		
		                        		
		                        		
		                        	
6.A Comparative Study of Da Vinci Robot System with Video-assisted Thoracoscopy in the Surgical Treatment of Mediastinal Lesions
DING RENQUAN ; TONG XIANGDONG ; XU SHIGUANG ; ZHANG DAKUN ; GAO XIN ; TENG HONG ; QU JIAQI ; WANG SHUMIN
Chinese Journal of Lung Cancer 2014;(7):557-562
		                        		
		                        			
		                        			Background and objective In recent years, Da Vinci robot system applied in the treatment of intratho-racic surgery mediastinal diseases become more mature. hTe aim of this study is to summarize the clinical data about mediasti-nal lesions of General Hospital of Shenyang Military Region in the past 4 years, then to analyze the treatment effect and prom-ising applications of da Vinci robot system in the surgical treatment of mediastinal lesions. Methods 203 cases of mediastinal lesions were collected from General Hospital of Shenyang Military Region between 2010 and 2013. hTese patients were di-vided into two groups da Vinci and video-assisted thoracoscopic surgery (VATS) according to the selection of the treatments. hTe time in surgery, intraoperative blood loss, postoperative drainage amount within three days atfer surgery, the period of bearing drainage tubes, hospital stays and hospitalization expense were then compared. Results All patients were successfully operated, the postoperative recovery is good and there is no perioperative death. hTe different of the time in surgery between two groups is Robots group 82 (20-320) min and thoracoscopic group 89 (35-360) min (P>0.05). hTe intraoperative blood loss between two groups is robot group 10 (1-100) mL and thoracoscopic group 50 (3-1,500) mL. hTe postoperative drainage amount within three days atfer surgery between two groups is robot group 215 (0-2,220) mL and thoracoscopic group 350 (50-1,810) mL. hTe period of bearing drainage tubes atfer surgery between two groups is robot group 3 (0-10) d and thora-coscopic group:5 (1-18) d. hTe difference of hospital stays between two groups is robot group 7 (2-15) d and thoracoscopic group 9 (2-50) d. hTe hospitalization expense between two groups is robot group (18,983.6±4,461.2) RMB and thoracoscopic group (9,351.9±2,076.3) RMB (All P<0.001). Conclusion hTe da Vinci robot system is safe and effcient in the treatment of mediastinal lesions compared with video-assisted thoracoscopic approach, even though its expense is higher.
		                        		
		                        		
		                        		
		                        	
7.Correlation between carotid intima-media thickness and glucose fluctuation in type 2 diabetic patients
Jinxin HUANG ; Xiaofeng Lü ; Pei LUO ; Xingguang ZHANG ; Xumin JIAO ; Dakun ZHAO
Chinese Journal of General Practitioners 2013;12(4):268-271
		                        		
		                        			
		                        			Objective To investigate the correlation between carotid intima-media thickness (CIMT) and glucose fluctuation in patients with type 2 diabetes mellitus (T2DM).Methods Sixty-eight T2DM patients admitted to Beijing Military General Hospital from March to August 2012 were enrolled in the study,including 32 cases with CIMT thickening (CIMT ≥ 0.9 mm) and 32 cases with normal CIMT (CIMT <0.9 mm).The 72 h continuous blood glucose levels were monitored from the day of admission.Results There were no significant differences in the gender,age,body mass index (BMI),systolic and diastolic blood pressure,HDL-C,LDL-C,CHO,TG,glycosylate hemoglobin (HbA1c),fasting blood glucose(FBG) and postprandial average blood glucose (MPBG) between two groups (P > 0.05).The atherosclerosis (AS) score and mean amplitude of glycemic excursion (MAGE),glucose standard deviation,frequency of glycemic excursion (FGE) and absolute mean of daily differences (MODD) in patients with thickening CIMT were (11 ± 7) years,(6.9 ± 3.0) mmol/L,(2.8 ± 1.2) mmol/L,(3.4 ± 1.5) times/d,(2.8 ± 1.3) mmol/L,(4.5 ± 1.0) score,respectively ; while those in patients with normal CIMT were (8 ±6) years,(4.2 ± 1.1) mmol/L,(1.6 ± 0.5) mmol/L,(2.2 ± 0.8) times/d,(2.0 ± 1.0) mmol/L,(3.3 ±0.6) score,respectively.There were significant differences between two groups (all P < 0.05).Pearson correlation showed that CIMT was positively correlated with MAGE,FGE,MODD,course of disease,diastolic blood pressure,LDL-C,MPBG and AS score (P < 0.05).Multiple stepwise regression analysis showed that MAGE,MBPG were the influencing factors of CIMT.Conclusions The CIMT of patients with T2DM is closely correlated with glucose fluctuation,indicating that reduction of blood glucose fluctuation and MAGE,MPBG levels may delay the occurrence of diabetic macroangiopathy.
		                        		
		                        		
		                        		
		                        	
8.Clinical value of acoustic radiation force impulse imaging and APRI for quantitative evaluating the degree of liver fibrosis in chronic hepatitis C patients
Dakun ZHANG ; Min CHEN ; Yang LIU ; Ruifang WANG ; Zhiyan LI ; Xiaoyu DONG ; Guangde ZHOU
Chinese Journal of Ultrasonography 2013;(1):30-33
		                        		
		                        			
		                        			Objective To investigate the diagnostic value of the acoustic radiation force impulse (ARFI) technology and AST/PLT ratio index (APRI) for the assessment of the liver fibrosis in chronic hepatitis C patients.Methods 107 patients with chronic hepatitis C were included,the subjects were underwent liver biopsy,liver function,blood count,as well as real-time acoustic elastography examination.The APRI was calculated according the following formula,APRI =AST (ULN)/PLT (109/L).ARFI and APRI were compared by correlation with liver fibrosis stage in chronic hepatitis C.Referring to the histologic fibrosis stage on liver biopsy,all the ARFI and the APRI value were assessed by using ROC curve analysis.The corresponding cut-off values,sensitivity and specificity were also calculated and compared.Results The mean values of ARFI and APRI were (1.26 ± 0.27)m/s and 0.30 ± 0.46 for the patients with S1,(1.45 ± 0.51)m/s and 0.29 ± 0.21 for those with S2,(2.03 ± 0.54) m/s and 0.59 ± 0.56 for those with S3,(2.29 ± 0.82) m/s and 0.63 ± 0.35 for those with S4,respectively.ARFI (r =0.61,P <0.001) had a better correlation with liver fibrosis stage in chronic hepatitis C than APRI (r =0.49,P <0.001).Cut-off points of ARFI and APRI were 1.529 m/s and 0.170 for S≥2,1.780 m/s and 0.277 for S≥3,1.780 m/s and 0.446 for S =4,respectively.Accordingly,the areas under the ROC curves for ARFI and APRI were 0.779 and 0.724 for S≥2,0.866 and 0.786 for S≥3,0.790 and 0.779 for S=4,respectively.Conclusions As a non-invasive technology,ARFI is more accurate when applied to evaluate liver fibrosis in patients with chronic hepatitis C than APRI.ARFI technology has potential value for quantitatme evaluation of the liver fibrosis for chronic hepatitis C.
		                        		
		                        		
		                        		
		                        	
9.Effects of transportation conditions on survival rate of umbilical cord mesenchymal stem cells
Dakun WANG ; Zhihui WANG ; Hong GUO ; Leling ZHANG
Chinese Journal of Tissue Engineering Research 2013;(36):6430-6435
		                        		
		                        			
		                        			BACKGROUND:General assessment of viability of umbilical cord mesenchymal stem cel s during transport is not considered at home and abroad. 
 OBJECTIVE:To explore the effects of different transportation conditions such as albumin and transport time on survival rate of umbilical cord mesenchymal stem cel s. 
 METHODS:Umbilical cord mesenchymal stem cel s cultured in vitro were divided into experimental and control groups. Each of group contained 3.15×109/L cel s in 3 mL normal saline. The experimental group contained 1%albumin in dark environment. The control group included two subgroups:dark preservation group with the absence of albumin and light preservation group with the presence of albumin. Cel counting, trypan blue staining and cel survival rate were compared at 0, 2, 4, 8, and 24 hours. 
 RESULTS AND CONCLUSION:Compared with the control group, no cel loss was observed in experimental group (with the presence of albumin in the dark) and a 90%viability ratio was achieved at 8 hours. In the control group without albumin, loss rate reached 38.5%and survival rate reached 86%at 8 hours. Results revealed that 1%albumin predominantly improved cel survival rate in long-distance transport of umbilical cord mesenchymal stem cel s. When transport time was more than 8 hours, cel loss rate increased and cel survival rate downregulated. Our experimental data demonstrated that umbilical cord mesenchymal stem cel s preserved in normal saline consisting of 1%albumin placing in dark environment at 16 ℃ apply to clinical application criterion in 8 hours.
		                        		
		                        		
		                        		
		                        	
10.Initial clinical study of virtual touch quantification for evaluation of hepatic fibrosis of chronic liver disease
Xinli ZHANG ; Meng LI ; Hui FENG ; Dakun ZHANG ; Ying SU ; Yanxian ZHOU ; Min CHEN ; Xia CHEN
Chinese Journal of Ultrasonography 2010;19(1):12-15
		                        		
		                        			
		                        			Objective To explore the clinical value of virtual touch quantification (VTQ) technique in assessing the hepatic fibrosis. Methods A total of 115 inpatients with chronic liver disease receiving liver biopsy were enrolled in this study, all patients liver tissue was checked by VTQ technique, and the results were compared with those of the control group including 80 healthy subjects. Results VTQ value was significantly different between the two groups (P = 0.0000).The VTQ value among different degree of hepatic fibrosis but between S0 and S1 had statistical significances (P = 0.0212, P = 0.0000).ROC curve displayed that VTQ value of 1.4 m/s could be used to diagnose middle-high-grade liver fibrosis, the sensitivity and specificity were 85.4 % and 64.7%, respectively. Conclusions VTQ can be used as a noninvasive and effective means for assessing the degree of hepatic fibrosis.
		                        		
		                        		
		                        		
		                        	
            
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