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Xuan Xie,Xijun Hua,Jianhua Li,Xiaobin Cao,Zhixiang Tian,Rui Peng,Bifeng Yin,Peiyun Zhang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.5
To enhance the friction and wear resistance of GCr15/PTFE sliding contact surfaces, the synergistic lubrication effect of micro-textures and solid lubricants were studied in this paper. Micro-textures were processed on GCr15 samples by Nd:YAG laser, which were filled with MoS 2 . Tribological performance tests were carried out on a Rtec-MFT 5000 tester. Tribological properties were optimal with the textures density of 20 % and depth of 9 μm. A continuous composite solid lubricating film was formed by PTFE and MoS 2 . As load increases, friction coefficient of the sample shows a rapid decline and then stabilizes. With the increase of reciprocating frequency, friction curve of the sample shows a trend of slight fluctuation. When frequency is 2.7 Hz, friction coefficient is the lowest. Tribological properties of PTFE/GCr15 contact surfaces could be significantly optimized by micro-textures and MoS 2 , which performs favorable prospect of engineering application such as guide rails, bearings, machinery seal, etc.
Sorption Behavior and Mechanism of Phosphate onto Natural Magnesite
Xie, Fazhi,Hu, Tingting,Oh, Won-Chun,Sheng, Dandan,Li, Haibin,Wang, Xuechun,Xie, Zhiyong,Li, Guolian,Han, Xuan,Xie, Wenjie,Sun, Mei Materials Research Society of Korea 2017 한국재료학회지 Vol.27 No.3
Removal of phosphate from environmental water has become more important to prevent eutrophication. In the present study, sorption behavior of phosphate onto magnesite was investigated under different conditions. The optimum pH of phosphate adsorption was determined to be 6.0. The adsorption capacity was found to decrease with increasing temperature, which indicates that a low temperature was beneficial for phosphate adsorption. The sorption capacity for phosphate was found to be 10.2 mg/g at an initial concentration of 100 mg/L and a dose of 2 g/L. The first order kinetic equation and Freundlich isotherm model fit the data well. Phosphate adsorption on magnesite was explained by electrostatic attraction and weak physical interactions.
Xuan Lihui,Xu Zheng,Luo Jinhua,Yin Wang,Yan Yuhui,Qu Can,Xie Zuozhong,Skonieczna Magdalena,Zhou Ping-Kun,Huang Ruixue 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-
Exposure to nanomicroplastics (nano-MPs) can induce lung damage. The gut microbiota is a critical modulator of the gut–lung axis. However, the mechanisms underlying these interactions have not been elucidated. This study explored the role of lactate, a key metabolite of the microbiota, in the development of lung damage induced by nano-MPs (LDMP). After 28 days of exposure to nano-MPs (50–100 nm), mice mainly exhibited damage to the lungs and intestinal mucosa and dysbiosis of the gut microbiota. Lactate accumulation was observed in the lungs, intestines and serum and was strongly associated with the imbalance in lactic acid bacteria in the gut. Furthermore, no lactate accumulation was observed in germ-free mice, while the depletion of the gut microbiota using a cocktail of antibiotics produced similar results, suggesting that lactate accumulation in the lungs may have been due to changes in the gut microbiota components. Mechanistically, elevated lactate triggers activation of the HIF1a/PTBP1 pathway, exacerbating nano-MP-induced lung damage through modulation of the epithelial–mesenchymal transition (EMT). Conversely, mice with conditional knockout of Ptbp1 in the lungs (Ptbp1flfl) and PTBP1-knockout (PTBP1-KO) human bronchial epithelial (HBE) cells showed reversal of the effects of lactate through modulation of the HIF1a/PTBP1 signaling pathway. These findings indicate that lactate is a potential target for preventing and treating LDMP.
Xie, Fazhi,Zhang, Fengjun,Xuan, Han,Ge, Yejun,Wang, Yin,Li, Guolian,Zhu, Lei,Oh, Won-Chun The Korean Ceramic Society 2014 한국세라믹학회지 Vol.51 No.5
In this work, a new method that utilizes L-cysteine salicylaldehyde Schiff-base modified macroporous polystyrene resin (PS-CSC) as an effective sorbent has been developed for preconcentration of trace cadmium and lead in environmental water samples. The effect of pH, the contact time, the elution conditions, the flow rate, the initial concentration of target metal ions, and the effects of interfering ions on the preconcentration of the analytes were investigated. The maximum adsorption capacity of PS-CSC under optimum conditions for cadmium and lead were found to be 6.03 - 18.17 mg/g and 12.58 - 36.13 mg/g when the initial concentration of metal ions between 5.0 - 90 mg/L. The limits of detection for cadmium and lead were 2.46 ng/L and $0.52{\mu}g/L$, with a preconcentration factor of 200. The developed method has been validated by analyzing certified reference material and successfully applied for the enrichment and determination of trace cadmium and lead from environmental water samples.
Fazhi Xie,Feng-Jun Zhang,Han Xuan,Yejun Ge,Yin Wang,Guolian Li,Lei Zhu,오원춘 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5
In this work, a new method that utilizes L-cysteine salicylaldehyde Schiff-base modified macroporous polystyrene resin (PSCSC)as an effective sorbent has been developed for preconcentration of trace cadmium and lead in environmental water samples. The effect of pH, the contact time, the elution conditions, the flow rate, the initial concentration of target metal ions, andthe effects of interfering ions on the preconcentration of the analytes were investigated. The maximum adsorption capacity of PSCSCunder optimum conditions for cadmium and lead were found to be 6.03 - 18.17 mg/g and 12.58 - 36.13 mg/g when the initialconcentration of metal ions between 5.0 - 90 mg/L. The limits of detection for cadmium and lead were 2.46 ng/L and 0.52 μg/L,with a preconcentration factor of 200. The developed method has been validated by analyzing certified reference material andsuccessfully applied for the enrichment and determination of trace cadmium and lead from environmental water samples.
Adsorption Behavior and Mechanism of Tripolyphosphate on Synthetic Goethite
Zhong, Yong,Sheng, Dandan,Xie, Fazhi,Li, Guolian,Li, Hui,Han, Xuan,Xie, Wenjie,Oh, Won-Chun The Korean Ceramic Society 2019 한국세라믹학회지 Vol.56 No.2
In order to study the transport behavior of tripolyphosphate (TPP) in aqueous solutions, the adsorption process of TPP on synthetic goethite, which exists stably in supergene environment, has been systematically studied. The adsorption properties under different conditions (pH, electrolyte presence, and temperature) were investigated. The adsorption of TPP in the presence of humic acid (HA)/fulvic acid (FA) has also been discussed in this paper. The results indicated that the adsorption capacity quickly increased within the first hour and equilibrium was reached within 24 h. The adsorption capacity decreased from 1.98 to 0.27 mg·g<sup>-1</sup> upon increasing the pH from 8.5 to 11.0, whereas the adsorption of TPP on goethite hardly changed with increasing electrolyte concentration. The results of analysis of the kinetic and isothermal models showed that the adsorption was more in accord with the pseudo second-order equation and Freundlich model. The adsorption capacity decreased obviously regardless of the order of addition of TPP, HA, and goethite. Subsequent addition of FA led to a large increase in the adsorption capacity, which might be attributed to the adsorption ability of FA. According to the predictions of the kinetic and isothermal models and the spectroscopic evidence (X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM)), the adsorption mechanism may be mainly based on surface complexation and physical adsorption.
Ke-Jing Huang*,Chun-Xuan Xu,Wan-Zhen Xie 대한화학회 2008 Bulletin of the Korean Chemical Society Vol.29 No.5
A poly(methyl red) film-modified glassy carbon electrode (PMRE) was fabricated for determination of norfloxacin (NFX). The electrochemical behavior of NFX was investigated and a well-defined oxidation peak with high sensitivity was observed at the film electrode. PMRE greatly enhanced the oxidation peak current of NFX owing to the extraordinary properties of poly(methyl red) film. Based on this, a sensitive and simple voltammetric method was developed for measurement of NFX. A sensitive linear voltammetric response for NFX was obtained in the concentration range of 1 10-6-1 10-4 mol/L and the detection limit was 1 10-7 mol/L using linear sweep voltammetry (LSV). The proposed method possessed advantages such as low detection limit, fast response, low cost and simplicity. The practical application of this new analytical method was demonstrated with NFX pharmaceuticals.
Dun Wanwan,Wei Xuan,Wang Lu,Liu Jingjing,Zhao Jing,Sun Peipei,Fang Congbing,Xie Xingbin 한국식물학회 2023 Journal of Plant Biology Vol.66 No.1
The strawberry (Fragaria×ananassa) is an economically important perennial crop plant, and its fruits are rich in vitamin C (l-ascorbic acid [AsA]) and other nutrients. l-galactono-1,4-lactone dehydrogenase (GalLDH) is a key enzyme in the terminal step of AsA biosynthesis pathway in plants. Here, the GalLDH gene (FaGalLDH) was cloned from ‘Benihoppe’ strawberries. AsA content increased during fruit development and peaked at the red-ripening stage, and AsA concentrations in diferent tissues were correlated with enzyme activity and transcription level of FaGalLDH. Transient over-expression of FaGalLDH in strawberry fruit increased its overall expression and AsA production signifcantly, whereas transient RNAi of FaGalLDH decreased its expression and AsA content. Furthermore, the optimum pH and temperature for FaGalLDH activity were 8.0 and 25 °C, respectively. Ectopic expression of the FaGalLDH gene in Arabidopsis resulted in higher AsA content and enzyme activity in transgenic lines than in wild-type plants. FaGalLDH over-expression resulted in enhanced tolerance to salt stress due to reduced accumulation of malondialdehyde, H2O2, and O2 .−, as well as higher survival rates, root length, proline content, and superoxide dismutase, peroxidase, and catalase activities. These results provide useful information regarding AsA biosynthesis and salt tolerance, which may help to improve strawberry fruit quality and productivity.
Yongfang Wang,Xin Zhang,Bin Wang,Yang Xie,Yi Wang,Xuan Jiang,Rongjia Wang,Ke Ren 대한영상의학회 2019 Korean Journal of Radiology Vol.20 No.5
Objective: To examine the potential of intravoxel incoherent motion (IVIM) and blood oxygen level-dependent (BOLD) magnetic resonance imaging for detecting renal changes after iodinated contrast-induced acute kidney injury (CI-AKI) development in a diabetic rabbit model. Materials and Methods: Sixty-two rabbits were randomized into 2 groups: diabetic rabbits with the contrast agent (DCA) and healthy rabbits with the contrast agent (NCA). In each group, 6 rabbits underwent IVIM and BOLD imaging at 1 hour, 1 day, 2 days, 3 days, and 4 days after an iohexol injection while 5 rabbits were selected to undergo blood and histological examinations at these specific time points. Iohexol was administrated at a dose of 2.5 g I/kg of body weight. Further, the apparent transverse relaxation rate (R2*), average pure molecular diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were calculated. Results: The D and f values of the renal cortex (CO) and outer medulla (OM) were significantly decreased compared to baseline values in the 2 groups 1 day after the iohexol injection (p < 0.05). A marked reduction in the D* values for both the CO and OM was also observed after 1 hour in each group (p < 0.05). In the OM, a persistent elevation of the R2* was detected for 4 days in the DCA group (p < 0.05). Histopathological changes were prominent, and the pathological features of CI-AKI aggravated in the DCA group until day 4. The D, f, and R2* values significantly correlated with the histological damage scores, hypoxiainducible transcription factor-1α expression scores, and serum creatinine levels. Conclusion: A combination of IVIM and BOLD imaging may serve as a noninvasive method for detecting and monitoring CIAKI in the early stages in the diabetic kidney.