New neo-lignan from Acanthopanax senticosus with protein tyrosine phosphatase 1B inhibitory activity

Jia Lin Li,Na Li,Shan-Shan Xing,Nan Zhang,BanBan Li,JianGuang Chen,안종석,Long Cui 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.11

New neo-lignan, (7S, 8R)-3-hydroxyl-4-methoxyl-balanophonin (1), together with seven known compounds(2–8)were isolated fromthe EtOAc-soluble extract ofAcanthopanax senticosus. The structure of the newneo-lignanwas elucidated with spectroscopic and physico-chemicalanalyses. All the isolates were evaluated for in vitro inhibitoryactivity against PTP1B, VHR and PP1. Among them, the newcompound (1) was found to exhibit selective inhibitoryactivity on PTP1B with IC50 value 15.2 ± 1.4 lM.

Fatigue optimization with combined ensembles of surrogate modeling for a truck cab

Jianguang Fang,Yunkai Gao,Guangyong Sun,Chengmin Xu,Qing Li 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.11

In this study, we propose the ensembles of surrogates for an industrial application of fatigue optimization problem that aims to maximizea truck cab’s fatigue life. After validating the numerical model, different ensembles of surrogates comprised polynomial responsesurface (PRS), radial basis function (RBF) and Kriging (KRG) models are established to approximate the fatigue life function. A hybridPSO algorithm, which integrates the standard PSO with sequential quadratic programming (SQP), is implemented here to seek a quasiglobaloptimum. Compared with individual surrogates, the ensembles of surrogates can attain more competent optima and yield a smallersurrogate error at the optimal point. Moreover, the hybrid PSO technique proves to search the better optima than the standard PSO in thefatigue optimization problem considered. Finally, it is found that a more accurate surrogate model may not necessarily produce a betteroptimum for the ensembles of surrogates, thus multiple ensembles are recommended without increasing much extra computational cost.

10-m long slim sandpack experiments to investigate gel system transport behavior in porous media

Jianguang Wei,Xin Zhang,Jiangtao Li,Runnan Zhou,Songze Liu 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.10

Understanding the transport behavior of a gel system in porous media is of great significance in enhancing oil recovery (EOR) for high water cut oil reservoirs. However, the length of the experiment models (sandpack or core sample) in current studies is usually in the range of centimeter scale, which is too short to track the full movement path of gel particles. In this work, 10-m long slim sandpacks were adopted to conduct gel flooding experiments. The pressure and polymer concentration distribution along the sandpack was tracked, and scanning electron microscope (SEM) technique was employed to observe the pore morphology after the gel flooding. The results show that the movement of polymer particles is usually within 7m away from the inlet due to the adsorption and retention in the porous medium. For 0.4 PV injection cases, SEM images show that the pore morphology at the inlet region exhibits a stable polymer network, while the network structure disappears at the outlet, along with the decrease of fluid viscosity from 620.1mPa·s to 1.2mPa·s. However, we can still find the stringy state polymer after 5m movement and the viscosity is 584.0mPa·s for 1 PV gel injection cases. Four characterization parameters, including equivalent viscosity, breakthrough pressure gradient, dimensionless gelation gradient, and plugging ratio, were proposed to quantitatively characterize the performance of gel flooding. In addition, empirical models were also obtained to predict the four parameters through multi-parameters fitting, and these models facilitate the characterization of the gel flooding performance. This is the first work, to the best of the authors’ knowledge, using long slim sandpack (10m) to experimentally study gel system transport in porous media, which provides theoretical implications in enhancing oil recovery.

Study on Axial Compression Behavior of Cross-Shaped and L-Shaped Multi-cavity Concrete-Filled Steel Tube Special Shaped Column

Hongbo Li,Yufei Tong,Jianguang Yin,Hubiao Zhang,Changyu Yan 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.1

Multi-cavity concrete-fi lled steel tube special shaped column (CFSTSSC) combines the excellent characteristics of multicavity steel tube and core concrete. CFSTSSC has the advantages of high bearing capacity, good ductility, and strong energy dissipation capacity. At present, accurate calculation methods for these kinds of structures are limited and research into crossshaped and L-shaped multi-cavity CFSTSSCs is not available. Therefore, the axial compression behavior of cross-shaped and L-shaped multi-cavity CFSTSSCs has been investigated, though experimental research and numerical simulation, in this study. First, axial compression tests were carried out on three cross-shaped and three L-shaped multi-cavity CFSTSSCs to analyze their failure modes, axial load-strain curve, ductility index, and ultimate bearing capacity. Then, fi nite element (FE) calculation models of cross-shaped and L-shaped multi-cavity CFSTSSCs were established. The FE models are in good agreement with the experimental results, which provides a foundation for further parameter analysis and failure mechanism study of special shaped columns. Finally, combining parameter analysis and limit equilibrium theory, equations for calculating the ultimate bearing capacity of cross-shaped and L-shaped multi-cavity CFSTSSCs were proposed. The results show that the error between the simplifi ed equation and the FE result is less than 15%, indicating that the equations can provide reference for practical engineering applications.

Carbon Nanotubes/MnO2 Composite Fabricated via Laser Welding and Electrodeposition as Flexible Electrode for Supercapacitors

Mingping He,Jianguang Li,Wanli Xu,Zhenqiang Dong,Yuechao Wu,Liang Lv 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.6

Carbon nanotubes (CNTs) were welded on the surface of thermoplastic polypropylene (PP) substrate by laser irradiation and then manganese dioxide (MnO2) was deposited on the surface of CNTs by electrochemical method to prepare CNTs/MnO2 flexible electrodes (L-CM). The microstructure and morphology of CNTs/MnO2 composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results showed that CNTs were welded on the surface of the substrate, adhering to each other to form a porous network structure. In addition, there were distinct small protrusions on the surface of CNTs, indicating that MnO2 had been successfully deposited on the surface of CNTs. Cyclic voltammogram (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques were employed to investigate the electrochemical performance of the composites. Compared with CNTs/MnO2 composite prepared via compaction (denoted as C-CM), L-CM composite prepared under the laser power of 0.75W (denoted as L-CM75) showed a larger capacitance of 214.6 F g-1 at the current density of 0.5 A g-1 and displayed excellent bendability, demonstrating capacitance retention of approximately 89.6% after 1000 bending cycles. The excellent performance of L-CM75 may be attributed to the fact that the CNTs welded on the substrate have formed an effective conductive network whose porous structure can facilitate easy access of electrolytes to the electrode, which results in enhancement of the electrochemical performance of L-CM75.

ROS-activated CXCR2+ neutrophils recruited by CXCL1 delay denervated skeletal muscle atrophy and undergo P53-mediated apoptosis

Xiang Yaoxian,Dai Junxi,Li Yao,You Zongqi,Zhang Junpeng,Huang Xinying,Nie Shuqi,Chen Yujie,Xu Lei,Liu Fengming,Jiang Junjian,Xu Jianguang 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Neutrophils are the earliest master inflammatory regulator cells recruited to target tissues after direct infection or injury. Although inflammatory factors are present in muscle that has been indirectly disturbed by peripheral nerve injury, whether neutrophils are present and play a role in the associated inflammatory process remains unclear. Here, intravital imaging analysis using spinning-disk confocal intravital microscopy was employed to dynamically identify neutrophils in denervated muscle. Slice digital scanning and 3D-view reconstruction analyses demonstrated that neutrophils escape from vessels and migrate into denervated muscle tissue. Analyses using reactive oxygen species (ROS) inhibitors and flow cytometry demonstrated that enhanced ROS activate neutrophils after denervation. Transcriptome analysis revealed that the vast majority of neutrophils in denervated muscle were of the CXCR2 subtype and were recruited by CXCL1. Most of these cells gradually disappeared within 1 week via P53-mediated apoptosis. Experiments using specific blockers confirmed that neutrophils slow the process of denervated muscle atrophy. Collectively, these results indicate that activated neutrophils are recruited via chemotaxis to muscle tissue that has been indirectly damaged by denervation, where they function in delaying atrophy.

On functionally-graded crashworthy shape of conical structures for multiple load cases

Tong Pang,Yinfeng Li,Hehe Kang,Guangyong Sun,Jianguang Fang,Qing Li 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.6

Many studies on energy absorbers have been focused on tapered tubes because they have significant advantages in crashworthinessand provide a desired constant load-deflection response. However, few studies have been reported on tapered tubes with nonlinearlyvariablediameters along the longitudinal direction. This paper presents thin-walled Functionally graded tapered tube (FGTT) with a diametervarying nonlinearly subject to axial (0°) and oblique (10°, 20°, 30°) impacts. To explore the advantages of FGTT, conventionalStraight/Conical circular tube (SCT/CCT) with the same mass are compared; and FGTTs with a gradient exponent n > 1 are found to bepreferable to others in terms of energy absorption capacity under small impact angles. Then, crashworthiness analyses of different crushingdistances are conducted and it is found that under a large impact angle (e.g. 20°, 30°), FGTT with a short crushing distance (e.g. 40mm) have a higher mean crashing force than long crushing distance (e.g. 120 mm), especially for n > 1. In addition, the effect of geometricparameters, such as the gradient exponent n and diameter range ΔD between top (incident) and bottom (distal) diameters of FGTTs,are also studied and it is found that the FGTT with ΔD = 40 mm and n > 1 exhibits better crashworthiness than the others under smallimpact angles (0°, 10°). This paper demonstrates that such FGTT structures have a certain potential to be an energy absorber.

Chemical Composition and Antimigraine Activity of Essential Oil of Angelicae dahuricae Radix

Jingbo Sun,He Li,Jinghui Sun,Huimin Liu,JianGuang Chen,Chunmei Wang 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.8

The aim of this study was to explore the chemical composition and the effect of essential oil of Angelicae dahuricae radix on a nitroglycerin (NTG)-induced rat model of migraine. The CO2 supercritical fluid extraction method was optimized for the extraction of essential oil of A. dahuricae radix (EOAD) and its chemical composition was determined. The migraine model was established by subcutaneous injection of NTG (10 mg/kg) 1 h after the last administration of EOAD. The therapeutic effect of EOAD and its underlying mechanism were assessed by monitoring behavioral changes, levels of nitric oxide (NO) in serum and brain tissues, plasma levels of calcitonin gene-related peptide (CGRP) and endothelin (ET), and ET/NO ratio. The optimal conditions for CO2 supercritical fluid extraction of EOAD, as determined by orthogonal test [L9(34)], were as follows: 2 h extraction time, 20 MPa pressure, 40°C temperature, and 30 mesh. The yield of EOAD was 1.8%. On gas chromatography–mass spectrometry, 45 peaks were found in EOAD, and 22 compounds were identified and quantified. The main constituents of EOAD were 1-dodecanol (13.71%), elemene (7.54%), palmitic acid ethyl ester (7.32%), α-pinene (6.25%), and 1-pentadecanol (6.08%). Compared with rat migraine model controls, EOAD (35, 70, and 140 mg/kg) significantly reduced the number of head shaking, head scratching, and hind leg shooting events, decreased serum and brain NO levels, decreased plasma CGRP, and increased ET levels in rats. ET/NO ratio was elevated to 28.68 in the EOAD high-dose group. EOAD ameliorates NTG-induced migraine in rats likely by modulating the levels of vasoactive substances.

Accuracy modeling, analysis and radical error distribution of 3-RPR planar parallel mechanism

Jian Ding,Changlong Ye,Suyang Yu,Jianguang Li,Jinguo Liu,Guangbo Hao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

Output accuracy performance is directly determined by geometric errors and working poses of a mechanism. Accuracy sensitivity as geometric error transmission coefficient, closely relates to pose configuration and geometric parameters. This research focuses on accuracy of a 3-RPR planar parallel mechanism: firstly, established 3 models in an analytic form, to describe relationship between output errors and geometric ones, then they are mutually verified statistically. Secondly, the anisotropy and periodic fluctuation of position errors, independently contributed by each category of geometric errors, are illustrated; and mirror symmetric trajectories and poses generating output errors with mirror symmetry, are also revealed by numerical simulation. Finally, the radical accuracy model in an analytic form, was established through variance and covariance analysis on output errors. We concluded that the radical error of the movable platform in central symmetric poses, follows Rayleigh distribution pattern. Through statistical comparison with Monte Carlo simulation, the radical error model was demonstrated, that provided a reference for accuracy design for other planar parallel mechanism.

Schisantherin A Improves Learning and Memory of Mice with D-Galactose-Induced Learning and Memory Impairment Through Its Antioxidation and Regulation of p19/p53/p21/ Cyclin D1/CDK4/RB Gene Expressions

Cong Liu,Weijing Sun,Ning Li,Jiaqi Gao,Chunyan Yu,Chunmei Wang,Jinghui Sun,Shu Jing,JianGuang Chen,He Li 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.7

Schisantherin A (SCA) was evaluated for possible function in restoring the learning and memory impairment induced by D-galactose in mice. ICR mice were treated with D-galactose subcutaneously (220 mg·kg−1), and followed by SCA in different doses (1.25, 2.50 and 5.00 mg·kg−1, administered orally) for 42 days. Effects of SCA on learning and memory were examined by step-through tests and Morris water maze tests. The activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) in the peripheral blood and hippocampus of mice were assayed by water-soluble tetrazolium-1 (WST-1) and thiobarbituric acid (TBA) methods. The contents of 8 hydroxy deoxy guanosine (8-OHdG) in the hippocampus of mice were detected by immunosorbent assay methods, respectively. Quantitative real-time PCR and Western Blot were respectively used to detect the expression of p19, p53, p21, cyclin D1, CDK4 and RB genes, and the phosphorylation of RB in the hippocampus of mice. We found that SCA significantly improved the learning and memory impairment induced by D-galactose in mice. After SCA treatment, SOD activity was increased and the content of MDA was decreased in both peripheral blood and hippocampus of mice. 8-OHDG content was also decreased in the hippocampus of mice. Furthermore, the expression of p19, p53 and p21 genes was reduced and the expression of cyclin D1 and CDK4 and the phosphorylation of RB protein were elevated in the hippocampus. SCA may improve the learning and memory impairment induced by D-galactose by enhancing the antioxidant capacity, and regulating the expression of p19/p53/p21/cyclinD1/CDK4 genes, and the phosphorylation of RB protein in the hippocampus of mice.