Effect of Concentrations of Fe2+ and Fe3+ on the Corrosion Behavior of Carbon Steel in Cl− and SO42− Aqueous Environments

Kui Xiao,Zhaoliang Li,Jialiang Song,Ziheng Bai,Wei Xue,Junsheng Wu,Chaofang Dong 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

The concentration of metal ions in aqueous environments signifcantly afects the formation of corrosion products and furthermetal corrosion. In this paper, the electrochemical behavior of carbon steel in the presence of Fe2+ or Fe3+ concentrationin Cl− and SO42− aqueous environments have been investigated using conventional electrochemical methods such as linearpolarization and alternating current impedance spectroscopy. The morphology and composition of carbon steel corrosionproducts were studied using scanning electron microscopy and laser Raman spectroscopy. The efects of corrosion productsand iron ions concentration on the corrosion of carbon steel were discussed. Corrosion products of carbon steel in aqueousenvironments were γ-FeOOH, γ-Fe2O3 and a small amount of α-Fe2O3. The addition of Fe2+ afected the cathode reactionof the electrode reaction, and promotes the formation of γ-FeOOH and Fe3O4. And with the increase of Fe2+ concentrationin the solution, the anode process of electrode reaction was suppressed. The addition of Fe3+ promoted the formation ofγ-Fe2O3 and Fe3O4. Fe3+ afected the ionization of water, causing the pH of the solution to drop. Fe3+ undergoes a redoxreaction with the matrix. Addition of Fe3+ ions promoted the formation of FeOOH, an intermediate product, which reactswith the anode product Fe2+. These factors all accelerated the corrosion process.

A newly characterized exopolysaccharide from Sanghuangporus sanghuang

Xiao-kui Ma,Xu She,Eric Charles Peterson,Yu Zhen Wang,Peng Zheng,Hongyan Ma,Kexin Zhang,Jian Liang 한국미생물학회 2019 The journal of microbiology Vol.57 No.9

Sanghuangporus sanghuang is a well-known pharmacodynamic and economically important edible fungus associated with mulberry (Morus spp.). A distinctly new exopolysaccharide (EPS), designated SHP-2 was obtained from S. sanghuang P0988 broth, and its structure and anti-aging prosperity were characterized. SHP-2 was found to be composed of a backbone of 4)-β-Manp-(1 4)-α-Araf-(1 3,4)-α-Glcp(1 3,4)-α-Glcp-(1 3,4)-α-Glcp-(1 3,4)-α-Glcp-(1 3,4)-α- Glcp-(1 6)-α-Galp-(1 4)-β-Manp-(1 and five branches, including four α-D-Glcp-(1 and one α-D-Manp-(1 SHP-2 was shown to increase antioxidant enzyme activities including catalase (CAT) and superoxide dismutase (SOD) activities, as well as trolox equivalent antioxidant (TEAC) capacity in serum of mice pre-treated with D-Gal, while reducing lipofuscin levels. SHP-2 exerted a favorable influence on immune organ coefficients and ameliorated the histopathological hepatic lesions and apoptosis in hepatocytes of Dgalactose- aged mice almost in a dose-dependent manner. Using the same analytical methods, on comparison with previously studied EPS compounds (i.e. SHP-1), SHP-2 was found to have more complex structure, larger molecule weight, and different anti-aging properties. The results presented here suggest that not only does EPS bioactivity vary with respect to molecular structures and molecule weight, but that multiple structures with different activity can be expressed by a single fungal strain. These results may help understanding the antiaging prosperity of these polysaccharides for use in health foods or dietary supplements.

Effects of Ubiquitin-conjugating Enzyme 2C on Invasion, Proliferation and Cell Cycling of Lung Cancer Cells

Tang, Xiao-Kui,Wang, Ke-Jian,Tang, Yu-Kui,Chen, Li Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

The aims of this study were to investigate the influence of ubiquitin- conjugating enzyme E2C (UBE2C) on biological behavior of lung cancer cells. Using MTT, flow cytometry and invasion assays, we detected UBE2C expression and evaluated its biological properties in these cells, including effects on proliferation, the cell cycle profile and invasive capability. Compared with control cells, the UBE2C transfected cells demonstrated increased cellular proliferation (p<0.05). UBE2C transfected cells also had a lower percentage in G1 phase and a higher percentage in S phase (p<0.05). Importantly, the UBE2C transfected cells had a notable enhancement of cell numbers penetrating the basement membrane compared with the control group (p<0.05). Ectopic up-regulation UBE2C promoted the growth of lung cancer cells in vivo. Furthermore, we found UBE2C increased the expression of cyclin D1 and MMP-2. These results show UBE2C may represent a potential therapeutic target for lung cancer.

HIF-1α and GLUT1 Gene Expression is Associated with Chemoresistance of Acute Myeloid Leukemia

Song, Kui,Li, Min,Xu, Xiao-Jun,Xuan, Li,Huang, Gui-Nian,Song, Xiao-Ling,Liu, Qi-Fa Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Aims: Much evidence suggests that increased glucose metabolism in tumor cells might contribute to the development of acquired chemoresistance. However, the molecular mechanisms are not fully clear. Therefore, we investigated a possible correlation of mRNA expression of HIF-$1{\alpha}$ and GLUT1 with chemoresistance in acute myeloid leukemia (AML). Methods: Bone marrow samples were obtained from newly diagnosed and relapsed AML (M3 exclusion) cases. RNA interference with short hairpin RNA (shRNA) was used to stably silence GLUT1 or HIF-$1{\alpha}$ gene expression in an AML cell line and HIF-$1{\alpha}$ and GLUT1 mRNA expression was measured by real-time quantitative polymerase chain reaction assay (qPCR). Results: High levels of HIF-$1{\alpha}$ and GLUT1 were associated with poor responsiveness to chemotherapy in AML. Down-regulation of the expression of GLUT1 by RNA interference obviously sensitized drug-resistant HL-60/ADR cells to adriamycin (ADR) in vitro, comparable with RNA interference for the HIF-$1{\alpha}$ gene. Conclusions: Our data revealed that over-expression of HIF-$1{\alpha}$ and GLUT1 might play a role in the chemoresistance of AML. GLUT1 might be a potential target to reverse such drug resistance.

我国房地产信托投资及其法律问题研究

肖奎喜(Xiao Kui Xi),周浩(Zhou Hao) 한국부동산법학회 2015 不動産法學 Vol.19 No.-

我国房地产产业经过几十年的发展, 已由房地产项目的开发逐渐转化为房地产金融的深化发展｡ 这是一个循序渐进的过程, 也是我国房地产产业良性发展的必经之路｡ 相比于以往房地产的大部分 银行借贷融资而言, 本文旨在探讨对于我国来说的一种新型地产融资方式——房地产信托｡ 由于房 地产信托在我国发展的时间不长, 相应的体制, 法律规则都不完善, 本文的落脚点是关于房地产信托 投资的相关法律法规问题的探讨, 指出目前存在的问题, 并给出相应的建议｡ After decades of development, China's real estate industry has gradually transformed from the development of real estate projects into the deepening development of real estate financial. This is a gradual process, its also the only way for the benign development of our country's real estate industry. Compared with the previous bank loan financing of real estate, this paper aims to explore a new way of financing for real estate in China -- the real estate trust. Our country's real estate trust has a brief history, so the system and the rule of law are not perfect. The purpose of this paper is to explore the related legal problems of real estate trust investment, then points out that the existing problems and puts forward some corresponding suggestions.

Modeling of diffusion-reaction behavior of sulfate ion in concrete under sulfate environments

Xiao-Bao Zuo,Wei Sun,Hua Li,Yu-Kui Zhao 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.10 No.1

This paper estimates theoretically the diffusion-reaction behaviour of sulfate ion in concrete caused by environmental sulfate attack. Based on Fick’s second law and chemical reaction kinetics, a nonlinear and nonsteady diffusion-reaction equation of sulfate ion in concrete, in which the variable diffusion coefficient and the chemical reactions depleting sulfate ion concentration in concrete are considered, is proposed. The finite difference method is utilized to solve the diffusion-reaction equation of sulfate ion in concrete, and then it is used to simulate the diffusion-reaction process and the concentration distribution of sulfate ion in concrete. Afterwards, the experiments for measuring the sulfate ion concentration in concrete are carried out by using EDTA method to verify the proposal model, and results show that the proposed model is basically in agreement with the experimental results. Finally, Numerical example has been completed to investigate the diffusion-reaction behavior of sulfate ion in the concrete plate specimen immersed into sulfate solution.

Aromatic Compounds from the Halotolerant Fungal Strain of Wallemia sebi PXP-89 in a Hypersaline Medium

Xiao-Ping Peng,Wei-Ming Zhu,Yi Wang,Pei-Pei Liu,Kui Hong,Hao Chen,Xia Yin 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

A new cyclopentanopyridine alkaloid, 3-hydroxy-5-methyl-5,6-dihydro-7H-cyclopenta[b]pyridin-7-one (1), together with 11 known aromatic compounds were isolated from the secondary metabolites of the halotolerant fungal strain Wallemia sebi PXP-89 in 10% NaCl. Their structures including the absolute configurations of (2S,3S)-1-(4-hydroxyphenyl)butane-2,3-diol (2), (2R,3S)-1-(4-hydroxyphenyl)butane-2,3-diol (3), and (S)-3-hydroxy-4-(4-hydroxyphenyl)-2-one (4) were elucidated by spectroscopic analysis and a modified Mosher’s method. Compound 1 exhibited antimicrobial activity against Enterobacter aerogenes with a MIC of 76.7 μM. The absolute configurations of compounds 2-4 were determined for the first time.

Synthesis and Antibacterial Activity of 1,3-Diallyltrisulfane Derivatives

Fang-Kui Ren,Xiao-Yan He,Li Deng,Bo-Heng Li,Dong-Soo Shin,Zhu-Bo Li 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.3

A series of novel 1,3-diallyltrisulfane analogues were synthesized and assayed in vitro for antimicrobial activity against Gram positive, Gram negative bacteria and fungi. The antimicrobial activity of the 1,3-diallyltrisulfane derivatives showed, on the whole, very potent towards all the tested Gram positive, Gram negative and fungi (MIC ranging from 4 to 256 μg/mL). 1,3-Di(pent-4-enyl)trisulfane 3b and 1,3-bis(3-methylbut-2-enyl)trisulfane 3e exhibited the strongest antibacterial activity among all the compounds, and both of them were more active than 1,3-diallyltrisulfane (DATS). Results indicated the relationship of either carbon number or lipophilicity with antimicrobial activity presented “V” shape. These observations provided some predictions in order to further design 1,3-diallyltrisulfane derivatives with antimicrobial activity.

Muscle-derived Stem Cells Differentiate into Functional Smooth Muscle Cells for Ureter Tissue Engineering: An Experimental Study

Zhan-Kui Zhao,Hong-Lian Yu,Fei Xiao,Shi-Wen Li,Wen-Biao Liao,Kai-Liang Zhao 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

We assessed the ability of muscle-derived stem cells (MDSC) to differentiate into smooth muscle cells (SMC) and their potential to promote the regeneration of smooth muscle with a vessel extracellular matrix (VECM)for tissue engineering of the ureter. MDSC were isolated,proliferated, and identified by flow cytometry. SMC phenotype differentiation was induced with a smooth muscle induction medium. Gene expression was evaluated by real-time quantitative polymerase chain reaction (PCR)and Western blot studies. The VECM was obtained by a decellularization process, and cytotoxic effects were evaluated by exposing the induced cells to a VECM extract. The induced cells were seeded onto VECM in vitro for 1 week, and then the compound grafts were used for ureter reconstitution in vivo. The grafts were obtained for histological studies at 2, 4, 8, and 16 weeks post-operation. Intravenous urography was used to evaluate renal function and ureteral patency. Flow cytometry demonstrated that the MDSC expressed Sca-1 and desmin, but did not express CD45. After induction, SMC phenotype gene expression was confirmed in the induced cells by real-time quantitative PCR and Western blot studies. VECM exhibited a nontoxic effect on the induced cells in vitro. At 16 weeks postoperation,a histological evaluation showed that multilayered urothelium and organized muscle fiber bundles had formed in the grafts. Intravenous urography demonstrated no evidence of ureteral stricture or hydroureteronephrosis. These results demonstrate that MDSC can be induced into SMC and that this was useful for promoting regeneration of smooth muscles for ureter tissue engineering. We assessed the ability of muscle-derived stem cells (MDSC) to differentiate into smooth muscle cells (SMC) and their potential to promote the regeneration of smooth muscle with a vessel extracellular matrix (VECM)for tissue engineering of the ureter. MDSC were isolated,proliferated, and identified by flow cytometry. SMC phenotype differentiation was induced with a smooth muscle induction medium. Gene expression was evaluated by real-time quantitative polymerase chain reaction (PCR)and Western blot studies. The VECM was obtained by a decellularization process, and cytotoxic effects were evaluated by exposing the induced cells to a VECM extract. The induced cells were seeded onto VECM in vitro for 1 week, and then the compound grafts were used for ureter reconstitution in vivo. The grafts were obtained for histological studies at 2, 4, 8, and 16 weeks post-operation. Intravenous urography was used to evaluate renal function and ureteral patency. Flow cytometry demonstrated that the MDSC expressed Sca-1 and desmin, but did not express CD45. After induction, SMC phenotype gene expression was confirmed in the induced cells by real-time quantitative PCR and Western blot studies. VECM exhibited a nontoxic effect on the induced cells in vitro. At 16 weeks postoperation,a histological evaluation showed that multilayered urothelium and organized muscle fiber bundles had formed in the grafts. Intravenous urography demonstrated no evidence of ureteral stricture or hydroureteronephrosis. These results demonstrate that MDSC can be induced into SMC and that this was useful for promoting regeneration of smooth muscles for ureter tissue engineering.

Robust H∞ Fuzzy Control for Discrete-time Nonlinear Systems

Li-Kui Wang,Xiao-Dong Liu 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.1

This paper studies the problem of robust H∞ control for discrete-time nonlinear systems presented as Takagi--Sugeno’s fuzzy models. The generalized non-parallel distributed compensation (non-PDC) law and non-quadratic Lyapunov function is constructed by the proposed homogeneouspolynomially basis-dependent matrix function (HPB-MF for abbreviation). Based on the generalized non-PDC law and non-quadratic Lyapunov function, some linear matrix inequalities (LMIs) are obtained by exploiting the possible combinations of the basis functions. These LMIs ensure the asymptotic stability of the closed-loop system and guarantee a norm bound constraint on disturbance attenuation. In addition, it is shown that the LMIs become less conservative as the degree of HPB-MF increases. The merit of the methods presented in this paper lies in their less conservatism than other methods, as shown by a numerical example borrowed from the literature.