Synthesis and Characterization of pH and Temperature Sensitive Hydrogel Based on Poly(N-isopropylacrylamide), Poly(ε-caprolactone), Methylacrylic Acid, and Methoxyl Poly(ethylene glycol)

Xu Xu,Jia Song,Ke Wang,YingChun Gu,Feng Luo,XiaoHai Tang,Ping Xie,ZhiYong Qian 한국고분자학회 2013 Macromolecular Research Vol.21 No.8

In this paper, a novel biodegradable and pH/thermo-sensitive hydrogel based on poly(ε-caprolactone),methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide was prepared by UV-initiated free radical polymerization. The hydrogels were characterized by Fourier transforms infrared ray. The thermal responsibility was investigated with the help of differential scanning calorimetry. Swelling behavior in aqueous medium with different pH value was studied in detail. When the pH value of the aqueous medium was increased from 1.2 to 7.2,the swelling ratio of the hydrogels increased accordingly. The morphology was observed by scanning electron microscopy, and the hydrolytic degradation behavior in different aqueous media (pH 1.2 and pH 7.2) was also investigated in detail. The prepared biodegradable pH/thermo-sensitive hydrogel based on poly(ε-caprolactone), methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide hold great promise in the development of a smart drug delivery system.

20(S)-ginsenoside Rg3 exerts anti-fi brotic effect after myocardial infarction by alleviation of fi broblasts proliferation and collagen deposition through TGFBR1 signaling pathways

Honglin Xu,Haifeng Miao,Guanghong Chen,Guoyong Zhang,Yue Hua,Yuting Wu,Tong Xu,Changlei Hu,Mingjie Pang,Leyi Tan,Xin Han,Bin Liu,Yingchun Zhou 고려인삼학회 2023 Journal of Ginseng Research Vol.47 No.6

Background: Myocardial fibrosis post-myocardial infarction (MI) can induce maladaptive cardiacremodeling as well as heart failure. Although 20(S)-ginsenoside Rg3 (Rg3) has been applied to cardiovasculardiseases, its efficacy and specific molecular mechanism in myocardial fibrosis are largely unknown. Herein, we aimed to explore whether TGFBR1 signaling was involved in Rg3's anti-fibrotic effectpost-MI. Methods: Left anterior descending (LAD) coronary artery ligation-induced MI mice and TGF-b1-stimulated primary cardiac fibroblasts (CFs) were adopted. Echocardiography, hematoxlin-eosin andMasson staining, Western-blot and immunohistochemistry, CCK8 and Edu were used to study the effectsof Rg3 on myocardial fibrosis and TGFBR1 signaling. The combination mechanism of Rg3 and TGFBR1 wasexplored by surface plasmon resonance imaging (SPRi). Moreover, myocardial Tgfbr1-deficient mice andTGFBR1 adenovirus were adopted to confirm the pharmacological mechanism of Rg3. Results: In vivo experiments, Rg3 ameliorated myocardial fibrosis and hypertrophy and enhanced cardiacfunction. Rg3-TGFBR1 had the 1.78 10 7 M equilibrium dissociation constant based on SPRi analysis,and Rg3 inhibited the activation of TGFBR1/Smads signaling dose-dependently. Cardiac-specific Tgfbr1knockdown abolished Rg3's protection against myocardial fibrosis post-MI. In addition, Rg3 downregulatedthe TGF-b1-mediated CFs growth together with collagen production in vitro through TGFBR1signaling. Moreover, TGFBR1 adenovirus partially blocked the inhibitory effect of Rg3. Conclusion: Rg3 improves myocardial fibrosis and cardiac function through suppressing CFs proliferationalong with collagen deposition by inactivation of TGFBR1 pathway.

NUMERICAL ANALYSIS OF THE MIXTURE FORMATION IN A TWOSTROKE WALL-GUIDED LPG DI ENGINE FOR EXTENDED-RANGE ELECTRIC VEHICLE

Xu Boyan,Jiang Longlong,Sun Chaodong,Liu Yingchun 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.2

The use of automotive LPG characteristics which are easy to evaporate vaporization and carry. The paper presents a design of extended-range electric vehicle for wall-guided two stroke LPG engine with direct injection combustion system. Based on the modified vehicle LPG spray model, a database describing the characteristics of vehicle LPG fuel was built and imported into the CFD software. And the accuracy of the model is verified by the Schlieren experimental results. The concentration and velocity field of the mixture in the cylinder under different load conditions are numerically analyzed. The analyzed result indicated that the start injection time θ = 60°−70°CA BTDC under part load condition, the plug electrode near the gathering of a richer mixture is easy to be fired at spark ignition time, the obvious formation of mixture in cylinder is formed and the overall air-fuel ratio is above 40 : 1. The start-transition working condition and large load conditions in the piston moves upward before closing the exhaust port to start injection LPG. The optimized LPG injection start time θ ensures that the fresh gas is locked in the cylinder when the exhaust port is closed (63°CA ABDC). In the ignition time of the spark plug, an ideal homogeneous mixture in the cylinder is realized.

Thermodynamic analysis of a novel adiabatic compressed air energy storage system with water cycle

Zhen Xu,Haiyang Yang,Yingchun Xie,Jinchi Zhu,Chaoqun Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

A novel water cycle compressed air energy storage system (WC-CAES) is proposed to improve the energy storage density (ESD) and round trip efficiency (RTE) of A-CAES. The new system decreases electricity consumption by recovering and reusing the hydraulic pressure of water. The thermodynamic characteristics of WC-CAES are evaluated by energy and advanced exergy analysis method. When the air storage pressure of WC-CAES is equal to the minimum storage pressure of A-CAES (4.2 MPa), the ESD and generalized storage density increase by 5.85 % and 32.41 %, respectively. When the air storage pressure increases to the same level as A-CAES (7.2 MPa), ESD and generalized storage density increase by 112 % and 162 %, respectively. In addition, the RTE increases by 1.6 % when the air storage pressure is 4.2 MPa. WC-CAES is therefore verified to be an effective way to improve the performance of conventional A-CAES.

Visual Fatigue Reduction Based on Depth Adjustment for DIBR System

( Ran Liu ),( Yingchun Tan ),( Fengchun Tian ),( Hui Xie ),( Guoqin Tai ),( Weimin Tan ),( Junling Liu ),( Xiaoyan Xu ),( Chaibou Kadri ),( Naana Abakah ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.4

A depth adjustment method for visual fatigue reduction for depth-image-based rendering (DIBR) system is proposed. One important aspect of the method is that no calibration parameters are needed for adjustment. By analyzing 3D image warping, the perceived depth is expressed as a function of three adjustable parameters: virtual view number, scale factor and depth value of zero parallax setting (ZPS) plane. Adjusting these three parameters according to the proposed parameter modification algorithm when performing 3D image warping can effectively change the perceived depth of stereo pairs generated in DIBR system. As the depth adjustment is performed in simple 3D image warping equations, the proposed method is facilitative for hardware implementation. Experimental results show that the proposed depth adjustment method provides an improvement in visual comfort of stereo pairs as well as generating comfortable stereoscopic images with different perceived depths that people desire.

Mechanism of the dynamic pressure caused by the instability of upper chamber coal pillars in Shendong coalfield, China

Weibing Zhu,Jingmin Xu,Yingchun Li 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.5

In Shendong coalfield, severe support failure accidents caused by the dynamic pressure occurred frequently when longwall faces extracting the lower coal seam progress below the chamber coal pillars. These incidents largely threaten the personnel safety and regular operations. The rationale of the dynamic pressure has been investigated based on the movement law of the overlying strata. Experimental and numerical simulations of a longwall face in Shigetai coal mine agree well with the qualitative explanations. It is shown that the failure of the chamber coal pillars causes the sudden break and even rotation of the key strata, thereby leading to strong dynamic load that crushes the supports in the longwall face. Several guidelines have been proposed to prevent the occurrence of the dynamic pressure, the capability of which has been demonstrated by in situ practice in two longwall faces in Shendong coalfield.

Atomic Force Microscopy of Asymmetric Membranes from Turtle Erythrocytes

Tian, Yongmei,Cai, Mingjun,Xu, Haijiao,Ding, Bohua,Hao, Xian,Jiang, Junguang,Sun, Yingchun,Wang, Hongda Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.8

The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.

Synthesis of ArOTiCl₃ complexes and their application for ethylene polymerization and copolymerization

Wang, Jianwei,Ren, Yingchun,Xu, Sheng,Mi, Puke Techno-Press 2017 Advances in materials research Vol.6 No.3

In this article, novel olefin polymerization catalyst with lower cost and simple synthetic process were developed, $ArOTiCl_3$ complexes [$(2-OMeC_6H_4O)TiCl_3(C1)$, $(2,4-Me_2C_6H_3O)TiCl_3(C2)$, $TiCl_3(1,4-OC_6H_4O)TiCl_3(C3)$, $TiCl_3(1,4-OC_6H_2O-Me_2-2,5)$ $TiCl_3(C4)$] and corresponding $(ArO)_2TiCl_2$ complexes [$TiCl_2(OC_6H_4-OMe-2)_2(C5)$ and $TiCl_2(OC_6H_3-Me_2-2,6)_2(C6)$] have been synthesized by the reaction of $TiCl_4$ with phenol, all these complexes were well characterized with $^1H$ NMR, $^{13}C$ NMR, MASS and EA. When combined with methylaluminoxane (MAO), the $ArOTiCl_3/MAO$ system shows high activity for ethylene copolymerization with 1-octene and copolymer was obtained with broaden molecular weight distribution (MWD). The $^{13}C$ NMR result of polymer indicates that the 1-octene incorporation in polymer reached up to 8.29 mol%. The effects of polymerization temperature, concentration of polymerization monomer and polymerization time on the catalytic activity have been investigated.

Atomic Force Microscopy of Asymmetric Membranes from Turtle Erythrocytes

Yongmei Tian,Mingjun Cai,Haijiao Xu,Bohua Ding,Xian Hao,Junguang Jiang,Yingchun Sun,Hongda Wang 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.8

The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.

MiR-26a promotes apoptosis of porcine granulosa cells by targeting the 3β-hydroxysteroid-Δ24-reductase gene

Zhang, Xiaodong,Tao, Qiangqiang,Shang, Jinnan,Xu, Yiliang,Zhang, Liang,Ma, Yingchun,Zhu, Weihua,Yang, Min,Ding, Yueyun,Yin, Zongjun Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.4

Objective: Apoptosis of ovarian granulosa cells (GCs) affects mammalian follicular development and fecundity. This study aimed to explore the regulatory relationship between microRNA-26a (miR-26a) and the 3β-hydroxysteroid-Δ24-reductase gene (DHCR24) gene in porcine follicular granular cells (pGCs), and to provide empirical data for the development of methods to improve the reproductive capacity of pigs. Methods: The pGCs were transfected with miR-26a mimic, miR-26a inhibitor and DHCR24-siRNA in vitro. The cell apoptosis rate of pGCs was detected by the flow cytometry. The secretion levels of estradiol (E2) and progesterone (P) in pGCs were detected by enzyme-linked immunosorbent assay. Double luciferase validation system was used to detect the binding sites between miR-26a and DHCR24 3'-UTR region. Qualitative real-time polymerase chain reaction and Western blotting were used to verify the DHCR24 mRNA and protein expression in pGCs, respectively, after transfecting with miR-26a mimic and miR-26a inhibitor. Results: Results showed that enhancement of miR-26a promoted apoptosis, and inhibited E2 and P secretion in pGCs. Meanwhile, inhibition of DHCR24 also upregulated the Caspase-3 expression, reduced the BCL-2 expression, promoted pGCs apoptosis, and inhibited E2 and P secretion in pGCs. There were the binding sites of miR-26a located within DHCR24 3'-UTR. Up-regulation of miR-26a inhibited DHCR24 mRNA and protein expression in pGCs. Conclusion: This study demonstrates that miR-26a can promote cell apoptosis and inhibit E2 and P secretion by inhibiting the expression of DHCR24 in pGCs.