ANALYSIS OF VEHICLE DRIVING STABILITY BASED ON LONGITUDINAL-LATERAL AND VERTICAL UNIFIED DYNAMICS MODEL

Fei Lai,Chaoqun Huang,Xin Ye 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.1

Vehicle driving stability is the basis of chassis integrated control and automatic driving. In this paper, we construct an 18 degrees of freedom (DOF) unified dynamics model of vehicle chassis. The unified dynamics model includes three subsystems: steering subsystem, brake subsystem and suspension subsystem, in which the coupling relationships among the three subsystems above are considered. Combined with phase plane analysis method, choosing the sideslip angle of vehicle center of gravity (c.g.) and yaw rate as the evaluation indexes, the influences of front wheel steering angle, road adhesion coefficient, braking mode of front and rear wheels and initial speed on vehicle driving stability are analyzed. In particular, phase plane and bifurcation analysis methods are used to study the influence of uneven road on vehicle driving stability, which has not been reported yet. The main contribution of this paper is to make a comprehensive analysis of the vehicle driving stability by the 18-DOF model above. Through the comprehensive simulation analysis of the above factors by Matlab/Simulink, we can fully grasp the driving stability law of the vehicle under different working conditions. With the above analysis method, the stability of various control systems designed for vehicle chassis can be evaluated more objectively.

Establishment and Simulation Analysis of 18 DOF Unified Dynamics Model of Automobile Chassis

Fei Lai,Cheng-Yue Jiang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.7

The unified dynamics modeling of automobile chassis is the foundation of the chassis integrated control. Previous researches mainly focused on one or two subsystems, which could not fully reflect the dynamics characteristics of automobile chassis. In this paper, a unified dynamics mathematical model involving 18 degrees of freedom (DOF) of a two-axle vehicle is established to evaluate the ride comfort and handling stability of the vehicle, based on the coupling relationship of vehicle longitudinal, lateral and vertical dynamics. In order to verify the correctness of the 18-DOF unified dynamics model, the following three methods are used: 1) comparison with other four submodels, 2) experimental verification and 3) co-simulation test. Both simulation and test results indicate that the unified dynamics mathematical model can be used to evaluate the comprehensive dynamics performance of automobile chassis, and it is beneficial for the subsequent research of chassis integrated control system.

Pestalotiolide A, a New Antiviral Phthalide Derivative from a Soft Coral-derived Fungus Pestalotiopsis sp.

Yan-Lai Jia,Fei-Fei Guan,Jie Ma,Chang-Yun Wang,Chang-Lun Shao 한국생약학회 2015 Natural Product Sciences Vol.21 No.4

Chemical investigation of the fermentation broth of a Soft Coral-Derived fungus Pestalotiopsis sp., led to the isolation of a new phthalide derivative, pestalotiolide A (1), three known analogues (2, 3 and 4), along with 5'-O-acetyl uridine (5) first isolated as a natural product. The structure of the new compound (1) was established by comprehensive spectroscopic analysis and chemical methods. Compounds 1 - 4 possessed varying degrees of antiviral activities, which was reported for the first time. Compared to the positive control ribavirin (IC50 = 418.0 μM), pestalotiolide A (1) exhibited significant anti-EV71 activity in vitro, with an IC50 value of 27.7 mM. Furthermore, the preliminary structure-activity relationship of antiviral activities was also discussed.

Orthosiphon stamineus Leaf Extract Protects Against Ethanol-Induced Gastropathy in Rats

Mun Fei Yam,Lee Fung Ang,Ibrahim Muhammad Salman,Omar Ziad Ameer,Vuanghao Lim,Lai Man Ong,Mariam Ahmad,Mohd. Zaini Asmawil,Rusliza Basir 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.5

Orthosiphon stamineus Benth., which is used as a gastroprotective herbal remedy in Malaysia, was assessed for its anti-ulcerogenic activity against ethanol-induced ulcers in rats. Fifty percent methanol was used to extract the oven-dried O. stamineus leaves. The extract was then lyophilized with a rotary evaporator and freeze-dried. Oral administration of O. stamineus methanolic extract (OSME) (125, 250, 500, and 1,000mg/kg) was found to significantly decrease the ulcer index (P<.01, P<.001, P<.001, and P<.001, respectively). Histological study of a section of the rat stomach also showed a marked improvement in the gastric mucosal damage in groups receiving OSME. In order to further investigate the gastroprotective mechanism of OSME, mucus secretion and lipid peroxidation level were estimated in vitro and ex vivo. OSME exhibited dose-dependent stimulation of mucus secretion (r=0.718, P<.001) and inhibition of lipid peroxidation in rat gastric mucosal homogenates (both in vitro [r=0.819, P<.05] and ex vivo [r=0.981, P<.05]). It was concluded that the gastroprotective mechanism of OSME was partly due to its ability to inhibit lipid peroxidation and stimulate gastric mucus secretion.

Functional Conservation of an AGAMOUS Orthologous Gene Controlling Reproductive Organ Development in the Gymnosperm Species Taxus chinensis var. mairei

Yongjun Fei,Zhi-Xiong Liu,Hai-Yan Xiong,Lai-Yun Li 한국식물학회 2018 Journal of Plant Biology Vol.61 No.1

Arabidopsis AGAMOUS (AG) has roles in specifying reproductive organ (stamens and carpels) identity, floral meristem determinacy, and repression of A-function. To investigate possible roles of AG orthologous genes in gymnosperm species and evolution of C function, we isolated and identified AG orthologous gene TcAG from Taxus chinensis var. mairei (family Taxaceae, order Coniferales), a member of the last divergant lineage from higher Conifer that sisters to Gnetales. Sequence alignment and phylogenetic analysis grouped TcAG into the gymnosperm AG lineage. TcAG was expressed in both developing male and female cones, but there was no expression in juvenile leaves. Ectopic expression of TcAG in an Arabidopsis ag mutant produced flowers with the third whorl petaloid stamen and fourth whorl normal carpel, but failed to convert first whorl sepals into carpeloid organs and second whorl petals into stamenoid organs. A 35S::TcAG transgenic Arabidopsis ag mutant had very early flowering, and produced a misshapen inflorescence with a shortened floral axis. Our results suggest that establishment of the complete C-function occurred gradually during AG lineage evolution even in gymnosperms.

Acupuncture for Treatment of Erectile Dysfunction: A Systematic Review and Meta-Analysis

Bao-yong Lai,Hui-juan Cao,Guo-yan Yang,Li-yan Jia,Suzanne Grant,Yu-tong Fei,Emma Wong,Xin-lin Li,Xiao-ying Yang,Jian-ping Liu 대한남성과학회 2019 The World Journal of Men's Health Vol.37 No.3

ChinaPurpose: To assess the effectiveness and safety of acupuncture for erectile dysfunction (ED).Materials and Methods: We searched six major English and Chinese databases included randomized controlled trials (RCTs) testing acupuncture alone or in combination for ED. Dichotomous data were presented as risk ratio (RR) and continuous data were presented as mean difference (MD) both with 95% confidence interval (CI). The Revman (v.5.3) was used for data analyses. Quality of evidence across studies was assessed by the online GRADEpro tool.Results: We identified 22 RCTs, fourteen of them involving psychogenic ED. Most of the included RCTs had high or unclear risk of bias. There was no difference between electro-acupuncture and sham acupuncture with electrical stimulation on the rate of satisfaction and self-assessment (RR, 1.50; 95% CI, 0.71–3.16; 1 trial). Acupuncture combined with tadalafil appeared to have better effect on increasing cure rate (RR, 1.31; 95% CI, 1.00–1.71; 2 trials), and International Index of Erectile Function-5 scores (MD, 5.38; 95% CI, 4.46–6.29; 2 trials). When acupuncture plus herbal medicine compared with herbal medicine alone, the combination therapy showed significant better improvement in erectile function (RR, 1.68; 95% CI, 1.31–2.15; 7 trials). Only two trials reported facial red and dizziness cases, and needle sticking and pruritus cases in acupuncture group. Conclusions: Low quality evidence shows beneficial effect of acupuncture as adjunctive treatment for people mainly with psychogenic ED. Safety of acupuncture was insufficiently reported. The findings should be confirmed in large, rigorously designed and well-reported trials.

Cardioprotective effect of ginsenoside Rb1 via regulating metabolomics profiling and AMP-activated protein kinase-dependent mitophagy

Jingui Hu,Ling Zhang,Fei Fu,Qiong Lai,Lu Zhang,Tao Liu,Boyang Yu,Junping Kou,Fang Li 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.2

Background: Ginsenoside Rb1, a bioactive component isolated from the Panax ginseng, acts as a remedy to prevent myocardial injury. However, it is obscure whether the cardioprotective functions of Rb1 are related to the regulation of endogenous metabolites, and its potential molecular mechanism still needs further clarification, especially from a comprehensive metabolomics profiling perspective. Methods: The mice model of acute myocardial ischemia (AMI) and oxygen glucose deprivation (OGD)-induced cardiomyocytes injury were applied to explore the protective effect and mechanism of Rb1. Meanwhile, the comprehensive metabolomics profiling was conducted by high-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS) and a tandem liquid chromatography and mass spectrometry (LC-MS). Results: Rb1 treatment profoundly reduced the infarct size and attenuated myocardial injury. The metabolic network map of 65 differential endogenous metabolites was constructed and provided a new inspiration for the treatment of AMI by Rb1, which was mainly associated with mitophagy. In vivo and in vitro experiments, Rb1 was found to improve mitochondrial morphology, mitochondrial function and promote mitophagy. Interestingly, the mitophagy inhibitor partly attenuated the cardioprotective effect of Rb1. Additionally, Rb1 markedly facilitated the phosphorylation of AMP-activated protein kinase a (AMPKa), and AMPK inhibition partially weakened the role of Rb1 in promoting mitophagy. Conclusions: Ginsenoside Rb1 protects acute myocardial ischemia injury through promoting mitophagy via AMPKa phosphorylation, which might lay the foundation for the further application of Rb1 in cardiovascular diseases.

Oligosaccharides are a key factor in prediction of amino acid digestibility in soybean meal of different origins when fed to growing pigs

Zhongchao Li,Qiuyun Wang,Fei Xie,Dewen Liu,Yakui Li,Zhiqian Lyu,Changhua Lai 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.12

Objective: The objective of this experiment was to determine apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of crude protein (CP) and amino acid (AA) in 15 sources of soybean meal (SBM) produced from soybeans from different countries and subsequently to establish equations for predicting the AID and SID in SBM based on their chemical composition. Methods: Eighteen barrows (57.9±6.1 kg) fitted with a simple T-cannula were allotted into three 6×6 Latin square designs. Each period comprised a 6-d adaption period followed by a 2-d collection of ileal digesta. The 15 test diets included SBM as a sole source of AA in the diet. Another nitrogen-free diet was used to measure basal endogenous losses of CP and AA. Chromic oxide (0.3%) was used as an inert marker in each diet. Results: The AID of lysine in SBM from China and USA tended to be greater than in SBM from Brazil (p<0.10). The SID of valine and proline in SBM from China was greater than in SBM from Brazil (p<0.05). The SID of lysine, threonine, cysteine and glycine in SBM from China tended to be greater than in SBM from Brazil (p<0.10). From a stepwise regression analysis, a series of AID and SID prediction equations were generated. The best fit equations for lysine in SBM were: AID lysine = 1.16 sucrose–1.81 raffinose+82.10 (R2 = 0.69, p<0.01) and SID lysine = 1.14 sucrose–1.93 raffinose–0.99 ether extract (EE)+85.26 (R2 = 0.77, p<0.01). Conclusion: It was concluded that under the conditions of this experiment, the oligosaccharides (such as sucrose and raffinose) can be used to predict the AID and SID of AA in SBM with reasonable accuracy.

Non-invasive biomarkers for liver inflammation in non-alcoholic fatty liver disease: present and future

Terry Cheuk-Fung Yip,Fei Lyu,Huapeng Lin,Guanlin Li,Pong-Chi Yuen,Vincent Wai-Sun Wong,Grace Lai-Hung Wong 대한간학회 2023 Clinical and Molecular Hepatology(대한간학회지) Vol.29 No.-

Inflammation is the key driver of liver fibrosis progression in non-alcoholic fatty liver disease (NAFLD). Unfortunately, it is often challenging to assess inflammation in NAFLD due to its dynamic nature and poor correlation with liver biochemical markers. Liver histology keeps its role as the standard tool, yet it is well-known for substantial sampling, intraobserver, and interobserver variability. Serum proinflammatory cytokines and apoptotic markers, namely cytokeratin-18, are well-studied with reasonable accuracy, whereas serum metabolomics and lipidomics have been adopted in some commercially available diagnostic models. Ultrasound and computed tomography imaging techniques are attractive due to their wide availability; yet their accuracies may not be comparable with magnetic resonance imaging-based tools. Machine learning and deep learning models, be they supervised or unsupervised learning, are promising tools to identify various subtypes of NAFLD, including those with dominating liver inflammation, contributing to sustainable care pathways for NAFLD.

Preparation and Preliminary Evaluation of Macroporous Magnetic Agarose Particles for Bioseparation

Jia-Li Gu,Hong-Fei Tong,Lai-Yu Sun 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.1

Macroporous magnetic agarose particles (MMAPs) were prepared with calcium carbonate as the porogent by the water-in-oil suspension thermal regeneration method. MMAPs with good sphericity and appropriate particle size were obtained. The physical properties of the beads were determined and it was found that the water content (92.1%), porosity (94.4%) and mean pore diameter (120.1 nm) of the MMAPs were higher than those for the normal magnetic particles, indicating successful generation of macropores after calcium carbonate addition. Compared with normal magnetic particles, the mass transfer of biomolecules in MMAPs was remarkably enhanced. Finally, MMAPs were modified with 5-amino-benzimidazol (ABI) ligand and the adsorption capacity of IgG reached 153 mg/mL, higher than that of the normal magnetic particles (126 mg/mL). Moreover, adsorption behavior of MMAPs to IgG was little changed after twenty-five recycled use. Hence, MMAPs prepared herein showed great potential for bioseparation.