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      • SCIESCOPUSKCI등재

        Putative multiple reaction monitoring strategy for the comparative pharmacokinetics of postoral administration Renshen-Yuanzhi compatibility through liquid chromatography-tandem mass spectrometry

        Yufei Sun,Guifang Feng,Yan Zheng,Shu Liu,Yan Zhang,Zifeng Pi,Fengrui Song,Zhiqiang Liu 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.1

        Background: Exploring the pharmacokinetic (PK) changes of various active components of single herbs and their combinations is necessary to elucidate the compatibility mechanism. However, the lack of chemical standards and low concentrations of multiple active ingredients in the biological matrix restrict PK studies. Methods: A putative multiple reaction monitoring strategy based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to extend the PK scopes of quantification without resorting to the use of chemical standards. First, the compounds studied, including components with available reference standard (ARS) and components lacking reference standard (LRS), were preclassified to several groups according to their chemical structures. Herb decoctions were then subjected to ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry analysis with appropriate collision energy (CE) in MS² mode. Finally, multiple reaction monitoring transitions transformed from MS² of ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were used for ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry to obtain the mass responses of LRS components. LRS components quantification was further performed by developing an assistive group-dependent semiquantitative method. Results: The developed method was exemplified by the comparative PK process of single herbs Radix Ginseng (RG), Radix Polygala (RP), and their combinations (RG-RP). Significant changes in PK parameters were observed before and after combination. Conclusion: Results indicated that Traditional Chinese Medicine combinations can produce synergistic effects and diminish possible toxic effects, thereby reflecting the advantages of compatibility. The proposed strategy can solve the quantitative problem of LRS and extend the scopes of PK studies.

      • KCI등재

        Automated assessment of cracks on concrete surfaces using adaptive digital image processing

        Yufei Liu,조수진,Jiansheng Fan,Billie F. Spencer, Jr. 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.4

        Monitoring surface cracks is important to ensure the health of concrete structures. However, traditional visual inspection to monitor the concrete cracks has disadvantages such as subjective inspection nature, associated time and cost, and possible danger to inspectors. To alter the visual inspection, a complete procedure for automated crack assessment based on adaptive digital image processing has been proposed in this study. Crack objects are extracted from the images using the subtraction with median filter and the local binarization using the Niblack\' s method. To adaptively determine the optimal window sizes for the median filter and the Niblack\' s method without distortion of crack object, an optimal filter size index (OFSI) is proposed. From the extracted crack objects using the optimal size of window, the crack objects are decomposed to the crack skeletons and edges, and the crack width is calculated using 4-connected normal line according to the orientation of the local skeleton line. For an image, a crack width nephogram is obtained to have an intuitive view of the crack distribution. The proposed procedure is verified from a test on a concrete reaction wall with various types of cracks. From the crack images with different crack widths and patterns, the widths of cracks in the order of submillimeters are calculated with high accuracy.

      • KCI등재

        Putative multiple reaction monitoring strategy for the comparative pharmacokinetics of postoral administration RensheneYuanzhi compatibility through liquid chromatographyetandem mass spectrometry

        Yufei Sun,Guifang Feng,Yan Zheng,Shu Liu,Yan Zhang,Zifeng Pi,Fengrui Song,Zhiqiang Liu 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.1

        Background: Exploring the pharmacokinetic (PK) changes of various active components of single herbsand their combinations is necessary to elucidate the compatibility mechanism. However, the lack ofchemical standards and low concentrations of multiple active ingredients in the biological matrix restrictPK studies. Methods: A putative multiple reaction monitoring strategy based on liquid chromatography coupledwith mass spectrometry (LCeMS) was developed to extend the PK scopes of quantification withoutresorting to the use of chemical standards. First, the compounds studied, including components withavailable reference standard (ARS) and components lacking reference standard (LRS), were preclassifiedto several groups according to their chemical structures. Herb decoctions were then subjected toultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometryanalysis with appropriate collision energy (CE) in MS2 mode. Finally, multiple reaction monitoringtransitions transformed from MS2 of ultrahigh-performance liquid chromatography coupled withquadrupole time-of-flight mass spectrometry were used for ultrahigh-performance liquid chromatographycoupled with triple quadrupole mass spectrometry to obtain the mass responses of LRS components. LRS components quantification was further performed by developing an assistive groupdependentsemiquantitative method. Results: The developed method was exemplified by the comparative PK process of single herbs RadixGinseng (RG), Radix Polygala (RP), and their combinations (RGeRP). Significant changes in PK parameterswere observed before and after combination. Conclusion: Results indicated that Traditional Chinese Medicine combinations can produce synergisticeffects and diminish possible toxic effects, thereby reflecting the advantages of compatibility. The proposedstrategy can solve the quantitative problem of LRS and extend the scopes of PK studies.

      • KCI등재

        State estimation of a heavy-duty hexapod robot with passive compliant ankles based on the leg kinematics and IMU data fusion

        Yufei Liu,Haibo Gao,Liang Ding,Guangjun Liu,Zongquan Deng,Nan Li 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

        To control autonomous walking of a legged robot, it is essential to obtain the instantaneous velocity and posture of the robot. This paper presents a full body state estimation algorithm for a hexapod robot to estimate the velocity and posture of the trunk body without geometric knowledge of the environment. The velocity and posture estimates of the hexapod robot with passive compliant ankles are further processed by a data fusion method that is proposed based on the extended Kalman filter (EKF) technique, utilizing the leg kinematics model of the robot and the readouts from an on–board inertial measurement unit (IMU). The absolute footholds of the hexapod robot are estimated together with the velocity and posture of the trunk body, with consideration of intermittent ground contacts. Experiments have been conducted on both flat and uneven terrains, and the results have confirmed the effectiveness of the proposed approach.

      • KCI등재

        A Novel Kernel SVM Algorithm with Game Theory for Network Intrusion Detection

        ( Yufei Liu ),( Dechang Pi ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.8

        Network Intrusion Detection (NID), an important topic in the field of information security, can be viewed as a pattern recognition problem. The existing pattern recognition methods can achieve a good performance when the number of training samples is large enough. However, modern network attacks are diverse and constantly updated, and the training samples have much smaller size. Furthermore, to improve the learning ability of SVM, the research of kernel functions mainly focus on the selection, construction and improvement of kernel functions. Nonetheless, in practice, there are no theories to solve the problem of the construction of kernel functions perfectly. In this paper, we effectively integrate the advantages of the radial basis function kernel and the polynomial kernel on the notion of the game theory and propose a novel kernel SVMalgorithm with game theory for NID, called GTNID-SVM. The basic idea is to exploit the game theory in NID to get a SVM classifier with better learning ability and generalization performance. To the best of our knowledge, GTNID-SVM is the first algorithm that studies ensemble kernel function with game theory in NID. We conduct empirical studies on the DARPA dataset, and the results demonstrate that the proposed approach is feasible and more effective.

      • SCIESCOPUS

        Automated assessment of cracks on concrete surfaces using adaptive digital image processing

        Liu, Yufei,Cho, Soojin,Spencer, Billie F. Jr,Fan, Jiansheng Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.14 No.4

        Monitoring surface cracks is important to ensure the health of concrete structures. However, traditional visual inspection to monitor the concrete cracks has disadvantages such as subjective inspection nature, associated time and cost, and possible danger to inspectors. To alter the visual inspection, a complete procedure for automated crack assessment based on adaptive digital image processing has been proposed in this study. Crack objects are extracted from the images using the subtraction with median filter and the local binarization using the Niblack's method. To adaptively. determine the optimal window sizes for the median filter and the Niblack's method without distortion of crack object an optimal filter size index (OFSI) is proposed. From the extracted crack objects using the optimal size of window, the crack objects are decomposed to the crack skeletons and edges, and the crack width is calculated using 4-connected normal line according to the orientation of the local skeleton line. For an image, a crack width nephogram is obtained to have an intuitive view of the crack distribution. The proposed procedure is verified from a test on a concrete reaction wall with various types of cracks. From the crack images with different crack widths and patterns, the widths of cracks in the order of submillimeters are calculated with high accuracy.

      • KCI등재

        Cyclic Behavior of Q345GJ Steel Used in Energy Dissipation Shear Links

        Xiaogang Liu,Yufei Liu 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.3

        The cyclic behavior of Q345GJ steel was explored by strain cycle tests, stress cycle tests and uniaxial tension tests. The results of strain cycle tests confirmed that Q345GJ steel has no cyclic hardening, and it had rare strain amplitude effect or strain history effect. The stress cycle tests confirmed that the cumulative plastic strain goes up stably under eccentric stress with increasing loading loops. Thus, it can be concluded that the hardening characteristics of Q345GJ coincide with kinematic hardening, having almost no isotropic hardening. The superposition of four nonlinear kinematic hardening model based on Chaboche’s constitutive model was used to predict the hardening characteristics of Q345GJ steel, and the parameters of the constitutive model were calibrated based on the test results. The numerical validation of the constitutive model confirmed that the proposed parameters can give good simulation for strain cycle behavior and stress cycle behavior of Q345GJ steel.

      • SCIESCOPUSKCI등재

        Putative multiple reaction monitoring strategy for the comparative pharmacokinetics of postoral administration Renshen-Yuanzhi compatibility through liquid chromatography-tandem mass spectrometry

        Sun, Yufei,Feng, Guifang,Zheng, Yan,Liu, Shu,Zhang, Yan,Pi, Zifeng,Song, Fengrui,Liu, Zhiqiang The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.1

        Background: Exploring the pharmacokinetic (PK) changes of various active components of single herbs and their combinations is necessary to elucidate the compatibility mechanism. However, the lack of chemical standards and low concentrations of multiple active ingredients in the biological matrix restrict PK studies. Methods: A putative multiple reaction monitoring strategy based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to extend the PK scopes of quantification without resorting to the use of chemical standards. First, the compounds studied, including components with available reference standard (ARS) and components lacking reference standard (LRS), were preclassified to several groups according to their chemical structures. Herb decoctions were then subjected to ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry analysis with appropriate collision energy (CE) in MS<sup>2</sup> mode. Finally, multiple reaction monitoring transitions transformed from MS<sup>2</sup> of ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were used for ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry to obtain the mass responses of LRS components. LRS components quantification was further performed by developing an assistive group-dependent semiquantitative method. Results: The developed method was exemplified by the comparative PK process of single herbs Radix Ginseng (RG), Radix Polygala (RP), and their combinations (RG-RP). Significant changes in PK parameters were observed before and after combination. Conclusion: Results indicated that Traditional Chinese Medicine combinations can produce synergistic effects and diminish possible toxic effects, thereby reflecting the advantages of compatibility. The proposed strategy can solve the quantitative problem of LRS and extend the scopes of PK studies.

      • KCI등재

        Feasibility of a Clinical-Radiomics Model to Predict the Outcomes of Acute Ischemic Stroke

        Zhou Yiran,Wu Di,Yan Su,Xie Yan,Zhang Shun,Lv Wenzhi,Qin Yuanyuan,Liu Yufei,Liu Chengxia,Lu Jun,Li Jia,Zhu Hongquan,Liu Weiyin Vivian,Liu Huan,Zhang Guiling,Zhu Wenzhen 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.8

        Objective: To develop a model incorporating radiomic features and clinical factors to accurately predict acute ischemic stroke (AIS) outcomes. Materials and Methods: Data from 522 AIS patients (382 male [73.2%]; mean age ± standard deviation, 58.9 ± 11.5 years) were randomly divided into the training (n = 311) and validation cohorts (n = 211). According to the modified Rankin Scale (mRS) at 6 months after hospital discharge, prognosis was dichotomized into good (mRS ≤ 2) and poor (mRS > 2); 1310 radiomics features were extracted from diffusion-weighted imaging and apparent diffusion coefficient maps. The minimum redundancy maximum relevance algorithm and the least absolute shrinkage and selection operator logistic regression method were implemented to select the features and establish a radiomics model. Univariable and multivariable logistic regression analyses were performed to identify the clinical factors and construct a clinical model. Ultimately, a multivariable logistic regression analysis incorporating independent clinical factors and radiomics score was implemented to establish the final combined prediction model using a backward step-down selection procedure, and a clinical-radiomics nomogram was developed. The models were evaluated using calibration, receiver operating characteristic (ROC), and decision curve analyses. Results: Age, sex, stroke history, diabetes, baseline mRS, baseline National Institutes of Health Stroke Scale score, and radiomics score were independent predictors of AIS outcomes. The area under the ROC curve of the clinical-radiomics model was 0.868 (95% confidence interval, 0.825–0.910) in the training cohort and 0.890 (0.844–0.936) in the validation cohort, which was significantly larger than that of the clinical or radiomics models. The clinical radiomics nomogram was well calibrated (p > 0.05). The decision curve analysis indicated its clinical usefulness. Conclusion: The clinical-radiomics model outperformed individual clinical or radiomics models and achieved satisfactory performance in predicting AIS outcome

      • KCI등재

        Mutations of ARX and non-syndromic intellectual disability in Chinese population

        Yufei Wu,Huan Zhang,Xiaofen Liu,Zhangyan Shi,Hongling Li,Zhibin Wang,Xiaoyong Jie,Shao-Ping Huang,Fu-Chang Zhang,Junlin Li,Ke-Jin Zhang,Xiao-Cai Gao 한국유전학회 2019 Genes & Genomics Vol.41 No.1

        Mutations of Aristaless-related homeobox (ARX) gene were looked as the third cause of non-syndromic intellectual disability (NSID), while the boundary between true disease-causing mutations and non-disease-causing variants within this gene remains elusive. To investigate the relationship between ARX mutations and NSID, a panel comprising six reported causal mutations of the ARX was detected in 369 sporadic NSID patients and 550 random participants in Chinese. Two mutations, c.428_451 dup and p.G286S, may be disease-causing mutations for NSID, while p.Q163R and p.P353L showed a great predictive value in female NSID diagnosis with significant associations (X2 = 19.60, p = 9.54e−6 for p.Q163R; X2 = 25.70, p = 4.00e−07 for p.P353L), carriers of these mutations had an increased risk of NSID of more than fourfold. Detection of this panel also predicted significant associations between genetic variants of the ARX gene and NSID (p = 3.73e−4). The present study emphasized the higher genetic burden of the ARX gene on NSID in the Chinese population, molecular analysis of this gene should be considered for patients presenting NSID of unknown etiology.

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