MiR-29a and MiR-140 Protect Chondrocytes against the Anti-Proliferation and Cell Matrix Signaling Changes by IL-1β

Li, Xianghui,Zhen, Zhilei,Tang, Guodong,Zheng, Chong,Yang, Guofu Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.2

As a degenerative joint disease, osteoarthritis (OA) constitutes a major cause of disability that seriously affects the quality of life of a large population of people worldwide. However, effective treatment that can successfully reverse OA progression is lacking until now. The present study aimed to determine whether two small non-coding RNAs miR-29a and miR-140, which are significantly down-regulated in OA, can be applied together as potential therapeutic targets for OA treatment. MiRNA synergy score was used to screen the miRNA pairs that potentially synergistically regulate OA. An in vitro model of OA was established by treating murine chondrocytes with IL-$1{\beta}$. Transfection of miR-29a and miR-140 via plasmids was investigated on chondrocyte proliferation and expression of nine genes such as ADAMTS4, ADAMTS5, ACAN, COL2A1, COL10A1, MMP1, MMP3, MMP13 and TIMP metallopeptidase inhibitor 1 (TIMP1). Western blotting was used to determine the protein expression level of MMP13 and TIMP1, and ELISA was used to detect the content of type II collagen. Combined use of miR-29a and miR-140 successfully reversed the destructive effect of IL-$1{\beta}$ on chondrocyte proliferation, and notably affected the MMP13 and TIMP1 gene expression that regulates extracellular matrix. Although co-transfection of miR-29a and miR-140 did not show a synergistic effect on MMP13 protein expression and type II collagen release, but both of them can significantly suppress the protein abundance of MMP13 and restore the type II collagen release in IL-$1{\beta}$ treated chondrocytes. Compared with single miRNA transfection, cotransfection of both miRNAs exceedingly abrogated the suppressed the protein production of TIMP1 caused by IL-$1{\beta}$, thereby suggesting potent synergistic action. These results provided1novel insights into the important function of miRNAs' collaboration in OA pathological development. The reduced MMP13, and enhanced TIMP1 protein production and type II collagen release also implies that miR-29a and miR-140 combination treatment may be a possible treatment for OA.

MiR-29a and MiR-140 Protect Chondrocytes against the Anti-Proliferation and Cell Matrix Signaling Changes by IL-1beta

Guofu Yang,Xianghui Li,Zhilei Zhen,Guodong Tang,Chong Zheng 한국분자세포생물학회 2016 Molecules and cells Vol.39 No.2

As a degenerative joint disease, osteoarthritis (OA) constitutes a major cause of disability that seriously af-fects the quality of life of a large population of people worldwide. However, effective treatment that can successfully reverse OA progression is lacking until now. The present study aimed to determine whether two small non-coding RNAs miR-29a and miR-140, which are significantly down-regulated in OA, can be applied together as potential therapeutic targets for OA treatment. MiRNA synergy score was used to screen the miRNA pairs that potentially synergistically regulate OA. An in vitro model of OA was established by treating murine chondrocytes with IL-1. Transfection of miR-29a and miR-140 via plasmids was investigated on chondrocyte proliferation and expression of nine genes such as ADAMTS4, ADAMTS5, ACAN, COL2A1, COL10A1, MMP1, MMP3, MMP13 and TIMP metallopeptidase inhibitor 1 (TIMP1). Western blotting was used to determine the protein expression level of MMP13 and TIMP1, and ELISA was used to detect the content of type II collagen. Combined use of miR-29a and miR-140 successfully reversed the destructive effect of IL-1 on chondrocyte proliferation, and notably affected the MMP13 and TIMP1 gene expression that regulates extracellular matrix. Although co-transfection of miR-29a and miR-140 did not show a synergistic effect on MMP13 protein expression and type II collagen release, but both of them can significantly suppress the protein abun-dance of MMP13 and restore the type II collagen release in IL-1 treated chondrocytes. Compared with single miRNA transfection, co-transfection of both miRNAs exceedingly abrogated the suppressed the protein production of TIMP1 caused by IL-1, thereby suggesting potent synergistic action. These results provided novel insights into the important function of miRNAs' collaboration in OA pathological development. The reduced MMP13, and enhanced TIMP1 protein production and type II collagen release also implies that miR-29a and miR-140 combination treatment may be a possible treatment for OA.

Prediction of operating reliability of multi-body mechanism in micro-switches considering parameter distribution and wear of parts

Donghui Li,Xue Zhou,Sanqiang Ling,Yue Jin,Guofu Zhai 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

Traditional method evaluates operating reliability by counting life-test results of a small number of samples, which ignores variability between individuals and cannot accurately reflect the true state. This paper proposes a model for predicting operational reliability of mechanism in a batch of micro-switches based on manufacturing parameters, in view of complex structure and diverse manufacturing parameters. A multi-body kinetic model based on manufacturing parameters and principle of action considering contact fatigue and wear was established, and the operating characteristics in the degradation process with sliding wear of joints were obtained. Finally, the linkage with revolute clearance in miniature circuit breaker (MCB) was used as numerical example application to perform investigation. Prediction results are consistent with batch experiments, which verifies accuracy of model. In addition, the optimal combination of clearances was obtained by using genetic algorithm based on predicted model, which increases locking reliability to 99.3 % after 10000 operation cycles.

A simulated experimental system and risk prediction method for ignition caused by overhead lines short-circuit

Donghui Li,Yuguang Zhong,Xue Zhou,Guofu Zhai 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.12

In windy weather, overhead lines swing and collide with each other, often resulting in short-circuits and arc faults. The line is partially molten and produces numerous hot metal particles, which fall and may ignite the fuels on the ground. This paper developed an experimental system to obtain hot particle dimensions at different short-circuit current levels. Based on the results of this experiment, an ignition prediction method was developed. The particle parameters from the experiments were used as a bridge that to complete the prediction from short-circuit current to ignition risk. A neural network was trained according to the experimental and calculated results, then used to predict the risk of ignition. The overhead lines in a forest were used as an example application to perform thte investigation. The results show that copper lines in a forest with needles on the ground create a high risk of ignition hazard.

Analysis on Self-breakdown Statistics Properties for a Spark Switch

Mo, Chen,Guofu, Li,Qinxiao, Dong,Zhifang, Liu,Zhiyuan, Li 대한전기학회 2014 The Journal of International Council on Electrical Vol.4 No.2

According to the working characteristics of over-voltage protective device for series compensation, the principle and structure of spark switch were introduced in this paper briefly. Special test loop and HV fast switch-off device were designed to evaluate the performance of spark swich in trials. Test data and mathematic statistic results revealed that the self-breakdown probability of spark switch obeyed the normal distribution and the cumulative distribution of spark switch self-breakdown had been less affected by different enviroment temperature. The number of trials was restricted to the characteristics of insulated gas and the electrode surface state in the practical application. Reasonable choice of test number can keep estimation error at a relatively low level, particularly for parameter estimation by using small sample of self-breakdown voltage. The conclusion is instructive to the development and engineering application of spark switch for over-voltage protective equipment of series compensation.

Numerical study of fly ash deposition process in low temperature economizer under SCR conditions

Shuangcheng Fu,Gang Cao,Guofu Ou,Faqi Zhou,Luyu Li 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.7

After the boiler of a thermal power plant in Nanjing was reformed for denitrification, the clogging of flyash particles occurred near the support beam of the economizer. The critical speed criterion under different workingconditions was constructed by Fluent custom code (UDF), and the change of fly ash deposition on the support beamof the economizer was simulated without ABS and with ABS. At the same time, the influence of the fin layout structureon the movement of smoke and fly ash particles was analyzed. The results show that the stagnation of fly ash particleson the supporting beam is the main cause of sediment clogging. Due to the production of ABS in the process ofdenitrification, the adhesion of fly ash particles is intensified. At the same time, the fin structure on the support beamhinders the lateral movement of fly ash particles, which causes the growth of clogged fly ash near the support plate. Onthis basis, an optimization plan for the fin structure is proposed, which improves the flue gas flow conditions andavoids the occurrence of clogging and growth of fly ash.

Presulfidation and activation mechanism of Mo/Al2O3 catalyst sulfided by ammonium thiosulfate

Mingxing Tang,Xuekuan Li,Hui Ge,Weibin Fan,Guofu Wang,Zhanjun Lyu 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.8

Mo/Al2O3 catalyst was presulfided with (NH4)2S2O3 to elucidate presulfidation and activation mechanism. Itis illustrated that the Mo oxide is firstly partially sulfided during presulfidation and then in situ reduced into MoS2−x inactivation, and finally sulfided to active state during hydrodesulfurization (HDS). A synergistic effect between the S2− andS6+ ions in (NH4)2S2O3 produces a positive influence on the HDS performance. The S2− ions contribute to the sulfidationof Mo ions, while the S6+ species interact with Al2O3 support, weakening the interaction of active species with support.

Analysis and improvement of output power drop of dynamic wireless power transfer systems with transmitting coil switching for inspection robots

Yishuo Ding,Jiangui Li,Longyang Wang,Chen Wang,Guofu Zhu,Yuying Cheng,Tianqi Yu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

Dynamic wireless power transfer (DWPT) has received extensive attention due to its advantages of high security, high convenience, and high efficiency. To solve the problems of the mutual inductance and output power drop of DWPT systems for inspection robots, a new DWPT system with a trapezoidal-rectangular coupler has been proposed. First, the DWPT system topology and the switching strategy of the transmitting coil are introduced. Second, the real-time mutual inductances of the coupler in linear and curved motion are derived. Third, a new trapezoidal transmitting coil is presented. Finally, the performance of the DWPT system with the trapezoidal-rectangular coupler (TRC) is tested and compared to the DWPT system with the rectangular-rectangular coupler (RRC). Experimental results show that the minimum mutual inductance of the TRC is increased by 58.71%, and that the minimum output power is more than doubled in curved motion. Moreover, the mutual inductance drop rates of the TRC in linear and curved motion are reduced by 21.23% and 18.42%, respectively. The output power drop rates of the TRC-DWPT system are reduced by 18.99% and 16.12%, respectively. In addition, the Litz wire consumption is reduced by 8.28% in linear motion.

Identification method of nonlinear maneuver model for unmanned surface vehicle from sea trial data based on support vector machine

Gongxing Wu,Jiawei Zhang,Guofu Li,Linling Wang,Qiang Yu,Jiamin Guo 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

In order to solve the difficulty of modeling the unmanned surface vehicle (USV) nonlinear maneuver model, a combination identification method of linear hydrodynamic coefficients and nonlinear hydrodynamic coefficients based on support vector machine (SVM) is proposed. The identification principle of USV hydrodynamic coefficients is briefly introduced and a regression algorithm of the SVM is derived for the USV maneuver model. Then, the linear hydrodynamic coefficients of the hull are identified by using a series of USV turning test data at small water-jet angles. And the large water-jet angle turning motion test data and the identified linear hydrodynamic coefficients are used to identify the nonlinear hydrodynamic coefficients for USV. The fourth-order Runge-Kutta method is used to design the USV maneuver simulation program, and a series of USV turning motion simulation experiments are carried out. The simulation data is compared with the corresponding USV sea trial data. Through comparative analysis, it is shown that the USV maneuver mathematical model established in this paper can describe the maneuverability of the USV. It is feasible to use the combination method of SVM to identify the hydrodynamic coefficient of USV.

Effect of Precipitate State on Mechanical Properties, Corrosion Behavior, and Microstructures of Al–Zn–Mg–Cu Alloy

Xiaoyan Peng,Yao Li,Guofu Xu,Jiwu Huang,Zhimin Yin 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.5

The mechanical properties, corrosion behavior and microstructures of the Al–Zn–Mg–Cu alloy under various ageing treatmentswere investigated comparatively. The results show that the tensile strength and corrosion resistance are stronglyaff ected by the precipitate state. Massive fi ne intragranular precipitates contribute to high strength. Discontinuous coarsegrain boundary precipitates containing high Cu content, as well as the narrow precipitate free zone, result in low corrosionsusceptibility. After the non-isothermal ageing (NIA) treatment, the tensile strength of 577 MPa is equivalent to that of579 MPa for the T6 temper. Meanwhile, the stress corrosion susceptibility r tf and the maximum corrosion depth are 97.8%and 23.5 μm, which are comparable to those of 92.8% and 26.7 μm for the T73 temper. Moreover, the total ageing timeof the NIA treatment is only 7.25 h, which is much less than that of 48.67 h for the retrogression and re-ageing condition.