Effects of Huzhangoside C on Dextran Sodium Sulfate-Stimulated Colitis in Mice

Limin Chen,Yonghong Zhang,Jinhuang Shen,Ying Wu,Fan Cao,Hongying Hua,Xinhua Ma 한국식품영양과학회 2024 Journal of medicinal food Vol.27 No.1

Chronic inflammation is a major risk factor for cancer. Inflammatory bowel disease (IBD) is a chronicinflammatory disease of the gastrointestinal tract, ultimately leading to a breakdown of intestinal barrier function. Clematisflorida var. plena is a folk prescription used to treat inflammation and rheumatism in She pharmacy. The bioactivity of C. florida var. plena is primarily due to triterpene saponins. Huzhangoside C (HZ) is an active component of C. florida var. plena. In this study, the anti-inflammatory effect of HZ on a mouse colitis model induced by dextran sulfate sodium (DSS) wasinvestigated. Result indicated a notable reduction in body weight loss and colon length shortening in HZ-mediated micecompared to DSS-stimulated control mice. Furthermore, inflammatory signaling mechanisms involving interleukin-6 andtumor necrosis factor-a were suppressed in HZ-treated mice. HZ treatment significantly suppressed the expression of nuclearfactor kappa B (NF-jB), STAT3, and iNOS in colon tissue. After HZ treatment, malondialdehyde and nitric oxide levels weresignificantly decreased, while Nrf-2, superoxide dismutase, and glutathione expression levels were notably improved. Theresult indicated that HZ could activate the Nrf-2 signal cascade, inhibit the expression of NF-jB, eNOS, and STAT3, andenhance the intestinal barrier function of DSS stimulated ulcerative colitis intestinal injury. The results suggest that HZ ispotential anti-inflammatory agent for treating IBD.

Risk Factors for Poor Outcomes Following Minimally Invasive Discectomy: A Post Hoc Subgroup Analysis of 2-Year Follow-up Prospective Data

Zihao Chen,Lei He,Lijun Huang,Zhongyu Liu,Jianwen Dong,Bin Liu,Ruiqiang Chen,Liangming Zhang,Peigen Xie,Limin Rong 대한척추신경외과학회 2022 Neurospine Vol.19 No.1

Objective: A post hoc subgroup analysis of prospectively collected data from a randomized controlled trial was conducted to identify risk factors related to poor outcomes in patients who underwent minimally invasive discectomy. Methods: Patients were divided into satisfied and dissatisfied subgroups based on Oswestry Disability Index (ODI), visual analogue scale (VAS) back pain score (VAS-back) and leg pain score (VAS-leg) at short-term and midterm follow-up according to the patient acceptable symptom state threshold. Demographic characteristics, radiographic parameters, and clinical outcomes between the satisfied and dissatisfied subgroups were compared using univariate and multivariate analysis. Results: A total of 222 patients (92.1%) completed 2-year follow-up, and the postoperative ODI, VAS-back, and VAS-leg were significantly improved after surgery as compared to preoperatively. Multivariate analysis indicated older age (p = 0.026), lateral recess stenosis (p = 0.046), and lower baseline ODI (p = 0.027) were related to poor short-term functional improvement. Higher baseline VAS-back (p = 0.048) was associated with poor short-term relief of back pain, while absence of decreased sensation (p = 0.019) and far-lateral disc herniation (p = 0.004) were associated with poorer short-term relief of leg pain. Lumbar facet joint osteoarthritis was identified as a risk factor for poor functional improvement (p = 0.003) and relief of back pain (p = 0.031). Disc protrusion (p = 0.036) predicted poorer relief of back pain at midterm follow-up. Conclusion: In this study, several factors were identified to be predictive of poor surgical outcomes following minimally invasive discectomy. (ClinicalTrials.gov number: NCT01997086).

Simulation analysis of cogging torque of permanent magnet synchronous motor for electric vehicle

Qiping Chen,Hongyu Shu,Limin Chen 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.12

This paper proposes a new approach to study generation mechanism and influence factors of cogging torque of permanent magnet synchronous motors, in order to improve the operational performance and riding comfort of electric vehicle. Based on energy method and Fourier expansion, the method of predicting cogging torque is proposed. Two-dimensional finite element model of in-wheel motor is established by Maxwell software, and electromagnetic character of that is analyzed. Skew slot, pole arc coefficient and width of slot mouth are analyzed and studied by finite element method, in order to realize the change regularity of cogging torque. Cogging torque curves under the different skew slots, the different pole arc coefficients and the different widths of slot mouth are obtained, which can effectively reduce the cogging torque of in-wheel motor, but they still exists some limitations. The final simulation analysis results are in good agreement with the theoretical predicting results, which indicates that this method can be used to afford a theoretical basis to reduce the cogging torque and optimize the in-wheel motor of electric vehicle in the future.

The investigation of a new fast timing system based on DRS4 waveform sampling system

Jinda Chen,Chengming Du,Jinda Chen,Herun Yang,Jie kong,Haibo Yang,Peng Ma,Guozhu Shi,limin Duan,Zhengguo Hu 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2

In the study of nuclear structure, the fast timing technique can be used to measure the lifetime of excitedstates. In the paper, we have developed a new fast timing system, which is made up of two LaBr3:Cedetectors and a set of waveform sampling system. The sampling system based on domino ring samplerversion 4 chip (DRS4) can digitize and store the waveform information of detector signal, with a smallervolume and higher timing accuracy, and the waveform data are performed by means of digital waveformanalysis methods. The coincidence time resolution of the fast timing system for two annihilation 511 keVg photon is 200ps (FWHM), the energy resolution is 3.5%@511 keV, and the energy linear response in thelarge dynamic range is perfect. Meanwhile, to verify the fast timing performance of the system, the152Gd-21þ state form bþ decay of 152Eu source is measured. The measured lifetime is 45.3(±5.0)ps, veryclose to the value of the National Nuclear Data Center (NNDC: 46.2((±3.9)ps). The experimental resultsindicate that the fast timing system is capable of measuring the lifetime of dozens of ps. Therefore, thesystem can be widely used in the research of the fast timing technology.

The polymorphisms of bovine PCSK1 gene and their associations with growth traits

Limin Shan,Jiajie Sun,Chunlei Zhang,Xingtang Fang,Chuzhao Lei,Xianyong Lan,Hong Chen 한국유전학회 2011 Genes & Genomics Vol.33 No.1

Proprotein convertase 1 (PCSK1) is an endopeptidase involved in proteolytic processing of peptide hormone precursors in granules of the regulated secretory pathway of endocrine cells and mutations in PCSK1 gene are thought to cause obesity. In the present study, based on PCR-SSCP and DNA sequencing methods, polymorphisms of the PCSK1 gene were detected in 858 individuals from five breeds (Nanyang cattle, Qinchuan cattle, Jiaxian cattle, Luxi cattle and Chinese Holstein). The results showed that only P_8 locus showed polymorphisms and 3 synonymous SNPs of PCSK1 gene were identified. Additionally, significant statistical difference was found in bovine birth weight and diplotype MM were 7.35% higher than diplotype XY.

Cable with discrete negative stiffness device and viscous damper: passive realization and general characteristics

Chen, Lin,Sun, Limin,Nagarajaiah, Satish Techno-Press 2015 Smart Structures and Systems, An International Jou Vol.15 No.3

Negative stiffness, previously emulated by active or semi-active control for cable vibration mitigation, is realized passively using a self-contained highly compressed spring, the negative stiffness device (NSD).The NSD installed in parallel with a viscous damper (VD) in the vicinity of cable anchorage, enables increment of damper deformation during cable vibrations and hence increases the attainable cable damping. Considering the small cable displacement at the damper location, even with the weakening device, the force provided by the NSD-VD assembly is approximately linear. Complex frequency analysis has thus been conducted to evaluate the damping effect of the assembly on the cable; the displacement-dependent negative stiffness is further accounted by numerical analysis, validating the accuracy of the linear approximation for practical ranges of cable and NSD configurations. The NSD is confirmed to be a practical and cost-effective solution to improve the modal damping of a cable provided by an external damper, especially for super-long cables where the damper location is particularly limited. Moreover, mathematically, a linear negative stiffness and viscous damping assembly has proven capability to represent active or semi-active control for simplified cable vibration analysis as reported in the literature, while in these studies only the assembly located near cable anchorage has been addressed. It is of considerable interest to understand the general characteristics of a cable with the assembly relieving the location restriction, since it is quite practical to have an active controller installed at arbitrary location along the cable span such as by hanging an active tuned mass damper. In this paper the cable frequency variations and damping evolutions with respect to the arbitrary assembly location are then evaluated and compared to those of a taut cable with a viscous damper at arbitrary location, and novel frequency shifts are observed. The characterized complex frequencies presented in this paper can be used for preliminary damping effect evaluation of an adaptive passive or semi-active or active device for cable vibration control.

Active mass damper control for cable stayed bridge under construction: an experimental study

Chen, Hao,Sun, Zhi,Sun, Limin Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.2

A cable stayed bridge under construction has low structural damping and is not as stable as the completed bridge. Control countermeasures, such as the installation of energy dissipating devices, are thus required. In this study, the general procedure and key issues on adopting an active control device, the active mass damper (AMD), for vibration control of cable stayed bridges under construction were studied. Taking a typical cable stayed bridge as the prototype structure; a lab-scale test structure was designed and fabricated firstly. A baseline FEM model was then setup and updated according to the modal parameters measured from vibration test on the structure. A numerical study to simulate the bridge-AMD control system was conducted and an efficient LQG-based controller was designed. Based on that, an experimental implementation of AMD control of the transverse vibration of the bridge model was performed. The results from numerical simulation and experimental study verified that the AMD-based active control was feasible and efficient for reducing dynamic responses of a complex structural system. Moreover, the discussion made in this study clarified some critical problems which should be addressed for the practical implementation of AMD control on real cable-stayed bridges.

Mechanical properties of self-drilling orthodontic micro-implants with different diameters.

Chen, Yan,Kyung, Hee Moon,Gao, Limin,Yu, Won-Jae,Bae, Eun-Ju,Kim, Sang-Min Angle Orthodontists Research and Education Foundat 2010 The Angle orthodontist Vol.80 No.5

<P>OBJECTIVE: The hypothesis to be tested is that peak-insertion torque of self-drilling micro-implants of an appropriate diameter correlates with peak-removal torque mechanically. MATERIALS AND METHODS: A total of 360 self-drilling micro-implants composed of five different types were used. They (24 of each group) were inserted in three types of artificial bone with the use of a driving torque tester at a speed of 15 rpm. Insertion torque was measured during the placement, while the removal torque was measured within 3 days after insertion. RESULTS: Most of the micro-implants in type A sheared before they were completely inserted in 40-pounds per cubic foot bone. The implants in other types were successfully inserted without implant breakage and bone fracture in all bone densities. There was a statistically significant correlation between insertion torque and removal torque (r > or = 0.43543, P = .0001). There were significant differences in insertion and removal torque among the diameters of implants and bone densities with an increasing tendency. The torque loss rates reduced as the diameter of the implant and bone density increased. CONCLUSIONS: Micro-implants with a diameter of less than 1.3 mm are unsuitable for insertion into a bone with a density greater than 40 pounds per cubic foot mechanically when one is using a self-drilling technique.</P>

Dynamic optimization design of the suspension parameters of car bodymounted equipment via analytical target cascading

Jie Chen,Yangjun Wu,Limin Zhang,Xiaolong He,Shijie Dong 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.5

Under dynamic conditions, the dynamic force between the suspended equipment and the car body is substantially increased. This increase not only affects the ride comfort but also substantially raises the likelihood of fatigue damage to the suspended equipment. A multiobjective analytical target cascading (ATC) optimization is proposed to improve the ride comfort of high-speed trains and reduce the vibration of the suspended equipment. A mathematical simulation model of the vehicle equipment system is established, and the acceleration frequency-response function expression of the car body and the suspension system is obtained. The comfort index of the car body and the acceleration root mean square (RMS) of the suspended equipment are calculated by combining the German vertical irregular track spectrum and the comfort filter function. Meanwhile, the ATC method is used to optimize the car body comfort index and the acceleration RMS of the underframe suspended equipment. Then, the availability of the optimization method is evaluated via numerical simulation. Compared with the original suspension scheme of the underframe equipment, when the running speed of the vehicle is 300 km/h, the RMS value of the vibrational acceleration of the underframe equipment after optimization decreases by 19.9 %, and the ride comfort indexes at the car body center and above the front and rear bogies are improved by 6.4 %, 0.1 %, and 1.1 %, respectively. Simulation results demonstrate that ATC optimization can improve the railway vehicle ride comfort and reduce the vibration of the suspended equipment. This paper provides a new approach to the suspension parameter design of equipment.

Cable with discrete negative stiffness device and viscous damper: passive realization and general characteristics

Lin Chen,Limin Sun,Satish Nagarajaiah 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.15 No.3

Negative stiffness, previously emulated by active or semi-active control for cable vibrationmitigation, is realized passively using a self-contained highly compressed spring, the negative stiffnessdevice (NSD).The NSD installed in parallel with a viscous damper (VD) in the vicinity of cable anchorage,enables increment of damper deformation during cable vibrations and hence increases the attainable cabledamping. Considering the small cable displacement at the damper location, even with the weakening device,the force provided by the NSD-VD assembly is approximately linear. Complex frequency analysis has thusbeen conducted to evaluate the damping effect of the assembly on the cable; the displacement-dependentnegative stiffness is further accounted by numerical analysis, validating the accuracy of the linearapproximation for practical ranges of cable and NSD configurations. The NSD is confirmed to be a practicaland cost-effective solution to improve the modal damping of a cable provided by an external damper,especially for super-long cables where the damper location is particularly limited. Moreover, mathematically,a linear negative stiffness and viscous damping assembly has proven capability to represent active orsemi-active control for simplified cable vibration analysis as reported in the literature, while in these studiesonly the assembly located near cable anchorage has been addressed. It is of considerable interest tounderstand the general characteristics of a cable with the assembly relieving the location restriction, since itis quite practical to have an active controller installed at arbitrary location along the cable span such as byhanging an active tuned mass damper. In this paper the cable frequency variations and damping evolutionswith respect to the arbitrary assembly location are then evaluated and compared to those of a taut cable witha viscous damper at arbitrary location, and novel frequency shifts are observed. The characterized complexfrequencies presented in this paper can be used for preliminary damping effect evaluation of an adaptivepassive or semi-active or active device for cable vibration control.