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Zheng Lin Zhao,Guang Wen Zhao,Li Li,Meng Quan Li,Li Xin Guan,Xu Dong Yang,Hou Zhong Li,Feng Lin,Jong Rok Lee,Rong Jie Zhao 한국독성학회 2009 Toxicological Research Vol.25 No.1
The effects of aqueous extract of Schizandra Chinensis Fruit (AESC) on cadmium-induced changes of monoamine neurotransmitters in the different brain regions of adult rats were investigated. Male rats were received intraperitoneal (i.p.) administration of CdCl₂ (0.6 ㎎/㎏/d) for 21 days and sacrificed 7 days after the last administration. Concentrations of norepinephrine (NE), dopamine (DA) in striatum and serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) in cortex were measured by HPLC. There were significant decreases of NE, DA, 5-HT and 5-HIAA in Cd intoxicated rats (P < 0.05), while pretreatment with AESC (20 ㎎/㎏/d or 60 mg/kg/d, p.o., 30 min before CdCl₂) greatly inhibited the decrease of monoamine transmitters, respectively (P < 0.05). Also, AESC significantly increased the reduction of glutathione contents and superoxide dismutase activities in cortex induced by CdCl₂. These results suggest that AESC ameliorates Cd-induced depletion of monoamine neurotransmitters in brain through its antioxidant activity.
Zheng-Fei Yan,Jian Guo,Feng-Hua Tian,Xin-Xin Mao,Yu Li,Chang-Tian Li 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.4
Schisandra chinensis has been used as traditional medicine. The structures of isolate active compounds (schisandrin B, deoxyschisandrin, schisandrin C) from S. chinensis were characterized by physical and spectroscopic analyses. Active compounds were tested for their potential to act as anti-melanogenesis or skin-whitening agents by their abilities to inhibit tyrosinase activity in the cell-free mushroom tyrosinase assay and cellular tyrosinase derived from B16 melanoma cells. The tyrosinase inhibitory activity was correlated to the inhibition of melanin productions in α-MSH-stimulated and unstimulated B16 cells. Cellular tyrosinase kinetics were analyzed and showed by Lineweaver- Burk plot. Schisandrin B was minimally cytotoxic (cell viability: 88.99% at 0.75 μM) and the IC50 value for suppression of mushroom tyrosinase activity was estimated as 0.6 μM. Zymography analysis demonstrated schisandrin B’s concentration-dependent effects and the kinetic analysis indicated schisandrin B’s noncompetitive-inhibitory action.
Reducing undesirable vibrations of planar linkage mechanism with joint clearance
Zheng Feng Bai,Xin Jiang,Fei Li,Ji Jun Zhao,Yang Zhao 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.2
An optimization design method is presented to reduce the undesirable vibrations caused by clearance for planar linkage mechanism. A clearance joint is defined and considered a contact/impact force constraint. Contact and impact force models for the clearance joint are established using a normal contact force model based on Hertz model with energy loss and a tangential friction model based on modified Coulomb model with dynamic friction coefficient, respectively. In view of the clearance joint, dynamic equations and optimization method for a planar four-bar mechanism are then presented as an application example. The optimization aims to minimize the maximum absolute acceleration peaks of the mechanism by determining the link lengths of the planar linkage mechanism. Finally, the optimization design is solved by a generalized reduced gradient algorithm. Results show evident decrease in vibration peaks of the mechanism and obvious reduction in the contact forces in the clearance joint, which contribute to a good performance of planar linkage mechanism systems.
Jing-Feng Li,Zhen-Yu Lin,Qi-Xin Zheng,Xiao-Dong Guo,Shu-Hua Yang,Hong-Wei Lu,Sheng-Hui Lan 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.5
Bone morphogenetic proteins (BMPs) play an important role in regulating osteoblast differentiation and subsequent bone formation, mainly evidenced by the induced osteogenic ability of BMP-2 from BMPs. However, BMP-2 alone does not induce the expected efficacy due to its short retention in vivo. In this study, a novel BMP-2-related peptide (designated P24) derived from the “knuckle epitope”of BMP-2 was coupled covalently to type I collagen derived from rat tail and observed under scanning electron microscopy (SEM) in low vacuum mode. The BMP-2-related peptide/collagen composite was implanted in vivo into the pocket of the quadriceps musculature of Sprague-Dawley (SD) rats and then harvested 3 or 6 weeks after surgery. It was found that lyophilized collagen retained a porous network structure with an average inner-diameter of 90 ~ 160 μm. Based on radiographic evaluation and histological examination, BMP-2-related peptide/collagen induced significant ectopic bone formation compared to that of rat tail collagen alone as a control. Our results indicate collagen served as a good carrier for newly synthesized BMP-2-related peptide and that the BMP-2-related peptide/collagen composite was an effective substitute in bone tissue engineering.
Zhao, Zheng Lin,Zhao, Guang Wen,Li, Li,Li, Meng Quan,Guan, Li Xin,Yang, Xu Dong,Li, Hou Zhong,Lin, Feng,Lee, Jong-Rok,Zhao, Rong Jie Korean Society of ToxicologyKorea Environmental Mu 2009 Toxicological Research Vol.26 No.1
The effects of aqueous extract of Schizandra Chinensis Fruit (AESC) on cadmium-induced changes of monoamine neurotransmitters in the different brain regions of adult rats were investigated. Male rats were received intraperitoneal (i.p.) administration of CdCl2 (0.6 mg/kg/d) for 21 days and sacrificed 7 days after the last administration. Concentrations of norepinephrine (NE), dopamine (DA) in striatum and serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) in cortex were measured by HPLC. There were significant decreases of NE, DA, 5-HT and 5-HIAA in Cd intoxicated rats (P < 0.05), while pretreatment with AESC (20 mg/kg/d or 60 mg/kg/d, p.o., 30 min before $CdCl_2$) greatly inhibited the decrease of monoamine transmitters, respectively (P < 0.05). Also, AESC significantly increased the reduction of glutathione contents and superoxide dismutase activities in cortex induced by $CdCl_2$. These results suggest that AESC ameliorates Cd-induced depletion of monoamine neurotransmitters in brain through its antioxidant activity.
A FREE BREATHING IMPEDANCE RHEOGRAM APPARATUS MADE OF MICROPROCESSOR
Hua, Feng Jian,Chao, Zhang Xin,Wei, Zheng,Xuan, Jin Pei,Qiou, Bai Yan 대한전자공학회 1992 HICEC:Harbin International Conference on Electroni Vol.1 No.1
The impedance rheogram is a modern non-invasive method used to observe the disease of each part of the body such as heart, liver and lung etc. Because of the breathing interference effect, the patients have to hold their breathing when they are being tested by conventional impedance rheogram apparatus. It is not convenient to observe those patients who are difficult to cooperate with doctor such as children and poor-function-heart patients. Therefore, we have developed the free breathing impedance rheogram apparatus by using microprocessor, it can effectively eliminate the interference of the breathing to impedance rheogram, so that patients can be tested in the free breathing. By this way, it can not only much improve measuring accuracy, and also extend clinical service extant. The digital filtering system that we have developed by using microprocessor is used for automatically tracking variation of rhythm of the heart by specific program and filtering interference of the breathing by in-phase superposing-averaging the impendance signal of the lung in free breathing. The present artical introduces the hardware structure and main technical targets of the free breathing impedance rheogram apparatus, and provides application results for grown-up healthful persons and the patients having heart or lung problems in clinical service. The results show that the effect filtering interference of the breathing to impedance rheogram is very obvious. This technique can be used In impedance rheogram of heart and liver etc, and lays down a foundation for developing monitor in clinical service. In addition, it can also be used in studying of sport-medicine and space-medicine. This result has gotten United States Patent on Jun. 25,1991.
Yun Feng Fu,Xin Hua Hu,Wei Rui Wang,Zheng Ge 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.1
This paper presents a novel electromechanical brake (EMB) with automatic wear adjustment function, which has been ignored in most previous studies. With the aim of investigating the parameter characteristics of the EMB system and analyzing the proposed function, the mathematical models of the DC motor, motor friction, worm drive, ball screw and load are established in MATLAB/Simulink. The differences between the simulation and the experiment under step, triangular wave, square wave and sinusoidal input signals are discussed. The parameter characteristics of clamping force-motor current and clamping force-ball screw displacement are obtained, which also verifies that the established model is correct. The results demonstrate that the automatic wear adjustment function of the new EMB could guarantee that the brake stroke and response time remain consistent across each braking manoeuvre.
Chao, Zhe,Zheng, Xin-Li,Sun, Rui-Ping,Liu, Hai-Long,Huang, Li-Li,Cao, Zong-Xi,Deng, Chang-Yan,Wang, Feng Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.7
Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs) expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR) analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation.