Overexpression and characterization of a novel cold-adapted and salt-tolerant GH1 β-glucosidase from the marine bacterium Alteromonas sp. L82

Jingjing Sun,Wei Wang,Congyu Yao,Fangqun Dai,Xiangjie Zhu,Junzhong Liu,Jianhua Hao 한국미생물학회 2018 The journal of microbiology Vol.56 No.9

A novel gene (bgl) encoding a cold-adapted β-glucosidase was cloned from the marine bacterium Alteromonas sp. L82. Based on sequence analysis and its putative catalytic conserved region, Bgl belonged to the glycoside hydrolase family 1. Bgl was overexpressed in E. coli and purified by Ni2+ affinity chromatography. The purified recombinant β- glucosidase showed maximum activity at temperatures between 25°C to 45°C and over the pH range 6 to 8. The enzyme lost activity quickly after incubation at 40°C. Therefore, recombinant β-glucosidase appears to be a cold-adapted enzyme. The addition of reducing agent doubled its activity and 2 M NaCl did not influence its activity. Recombinant β-glucosidase was also tolerant of 700 mM glucose and some organic solvents. Bgl had a Km of 0.55 mM, a Vmax of 83.6 U/mg, a kcat of 74.3 s-1 and kcat/Km of 135.1 at 40°C, pH 7 with 4-nitrophenyl-β-D-glucopyranoside as a substrate. These properties indicate Bgl may be an interesting candidate for biotechnological and industrial applications.

Effects of V2O5 on sinterability and microwave dielectric properties of NaCa4V5O17 ceramics

Guoguang Yao,Yang Li,Jingjing Tan,Cuijin Pei,Yan Zhang,Jia Chen 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.3

The NaCa4V5O17 ceramics owing low sintering temperature had been prepared via conventional solid state reaction methodusing V2O5 as vanadium source. The sinterability, microwave dielectric characterisations and compatibility with Ag wereinvestigated. Pure phase NaCa4V5O17 with triclinic structure was confirmed by Rietveld refinement and Raman spectrum. Thepermittivity (εr) and quality factor (Qxf) values mainly depended on the relative density, whereas the temperature coefficientof resonant frequency (τf) value was closely connected with the tetrahedral distortion of V(1)O4. The NaCa4V5O17 ceramicssintered at 800 oС owned high densification and moderate microwave dielectric performances under 10.7 GHz: εr = 9.5, Q×f= 34,200 GHz, τf = -90.0 ppm/oС, but poor chemical compatibility with Ag paste.

Research on Complex Products based on Digital Layout Design and Simulation Modeling

Nuo Zhang,Jingjing Jiao,Hongxiu Liu,Zhen Yao 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.8

From the point of view of digital product development, this paper makes a deep discussion and research on the key technologies of pipeline layout design, pipeline layout optimization, and assembly simulation in the process of complex product development. We introduce an automatic pipe layout techniques based on improved rapidly exploring random tree, it could able to quickly establish the framework model of pipeline system, on this basis are discussed a pipeline of the simulated annealing algorithm based on automatic optimization algorithm, and interactive pipeline layout method, using computer artificial intelligence and design personnel manual intervention method to improve the quality of pipe layout. Also, we make the system realization of automatic layout of pipe line, and put forward related Suggestions.

Effect of LiF addition on the sinterability, crystal structure and microwave dielectric properties of Li3Mg4NbO8 ceramics

Wei Jin,Jingjing Tan,Jiaxin Yan,Yao Tao,Ningning Yao,Xiaomeng Ruan,Cuijin Pei 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.6

The normative solid-state reaction process was adopted to prepare Li3Mg4NbO8 ceramics with LiF addition. We investigatedthe impacts of LiF additive on the crystal structure, sinterabillity as well as dielectric performance at microwave region of theLi3Mg4NbO8-basic ceramics. XRD analysis confirmed that the addition of LiF to Li3Mg4NbO8 lead to the formation of newphase Li4Mg4NbO8F with cubic rock salt structure. The densified temperature of Li3Mg4NbO8-basic ceramics could beeffectively reduced from 1150 oC to 900 oC with LiF addition. Both the permitivity (εr) and quality factor (Qf) of presentceramics were is closely correlated with the bulk density and cell volume. The 900 oC-sintered Li3Mg4NbO8-basic ceramicsowned excellent chemical compatibility with silver and optimized microwave dielectric performance (εr ~13. 4, Qf ~ 32,400GHz at 9.4 GHz, and temperature coefficient of resonant frequency (τf) ~ -43.0 ppm/℃).

The investigation of pH threshold value on the corrosion of steel reinforcement in concrete

Qi Pu,Yan Yao,Ling Wang,Xingxiang Shi,Jingjing Luo,Yifei Xie 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.3

The aim of this study is to investigate the pH threshold value for the corrosion of steel reinforcement in concrete. A method was designed to attain the pH value of the pore solution on the location of the steel in concrete. Then the pH values of the pore solution on the location of steel in concrete were changed by exposing the samples to the environment (CO25%, RH 40%) to accelerate carbonation with different periods. Based on this, the pH threshold value for the corrosion of steel reinforcement had been examined by the methods of half-cell potential and electrochemical impedance spectra (EIS). The results have indicated that the pH threshold value for the initial corrosion of steel reinforcement in concrete was 11.21. However, in the carbonated concrete, agreement among whether steel corrosion was initiatory determined by the detection methods mentioned above could be found.

Application of Three-phase Hollow Fiber LPME using an Ionic Liquid as Supported Phase for Preconcentration of Malachite Green from Water Samples with HPLC Detection

Zou, Yanmin,Zhang, Zhen,Shao, Xiaoling,Chen, Yao,Wu, Xiangyang,Yang, Liuqing,Zhu, Jingjing,Zhang, Dongmei Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

A novel three-phase hollow fiber liquid phase microextraction was developed for the determination of malachite green (MG) in environmental waters, which selected [BMIM][$PF_6$] mixed with 1% trioctylphosphine oxide (TOPO) as supported phase. Several parameters (accepter phase pH, sample pH, supported phase membrane, volume of accepter phase, salinity, extraction time) that could affect extraction performance were investigated. Under the optimal extraction conditions, the established approach showed excellent characters as: high enrichment factor (212), wide linear range ($0.20-100{\mu}gL^{-1}$), low detection limit ($0.01{\mu}gL^{-1}$), good reproducibility (RSD, 8.9%, n=5) and satisfactory recovery (84.0-106.2%). The method was applied to detect MG at Yangtze River and pond waters in Zhenjiang, Jiangsu province, and 4 sites among 15 sampling sites were found MG with the concentration of $1.73-11.06{\mu}gL^{-1}$, which confirmed that the proposed environmentally friendly method was simple and effective for monitoring MG in aquatic system.

A Novel Approach for Determining Pile Spacing considering Interactions among Multilayered Sliding Masses in Colluvial Landslides

Haikuan Zhang,Changdong Li,Wenmin Yao,Jingjing Long 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.9

It is reported that there are many colluvial landslides with multilayered sliding masses; however, previous studies of the pile spacing of stabilizing piles mainly focus on the single-layered sliding mass, which may lead to design errors for pile spacing. Consequently, the paper presents a novel method to determine the pile spacing with considering interactions of multilayered sliding masses in colluvial landslides. Based on a generalized landslide model, equations for calculating stability coefficients of multilayered sliding masses were improved by examining the interactions among sliding masses. An accordingly colluvial landslide model with double-layered sliding masses was established by the finite differential method. The distribution of vertical landslide driving force and horizontal loading between adjacent piles were studied based on the colluvial landslide. A novel method of calculating the maximum pile spacing and minimum pile spacing was deduced by considering the soil arching effect and the interactions among multilayered sliding masses. The reasonable pile spacing was obtained considering cost and performance of stabilizing piles. The calculational process, which determines optimal pile spacing in multilayered masses, were shown based on the Bazimen landslide. The variations in pile spacing affected by various soil-layer sequences was illustrated by employing the Bazimen landslide model. The calculation results indicate that the pile spacing is positively correlated with the depth of soil with the maximum resistance sliding force. Effectiveness and significance of the presented method were proved through verify the calculational results by using numerical modeling approaches.

Application of Three-phase Hollow Fiber LPME using an Ionic Liquid as Supported Phase for Preconcentration of Malachite Green from Water Samples with HPLC Detection

Yanmin Zou,Zhen Zhang,Xiaoling Shao,Yao Chen,Xiangyang Wu,Liuqing Yang,Jingjing Zhu,Dongmei Zhang 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

A novel three-phase hollow fiber liquid phase microextraction was developed for the determination of malachite green (MG) in environmental waters, which selected [BMIM][PF6] mixed with 1% trioctylphosphine oxide (TOPO) as supported phase. Several parameters (accepter phase pH, sample pH, supported phase membrane, volume of accepter phase, salinity, extraction time) that could affect extraction performance were investigated. Under the optimal extraction conditions, the established approach showed excellent characters as: high enrichment factor (212), wide linear range (0.20-100 μg L-1), low detection limit (0.01 μg L-1), good reproducibility (RSD, 8.9%, n=5) and satisfactory recovery (84.0-106.2%). The method was applied to detect MG at Yangtze River and pond waters in Zhenjiang, Jiangsu province, and 4 sites among 15 sampling sites were found MG with the concentration of 1.73-11.06 μg L-1, which confirmed that the proposed environmentally friendly method was simple and effective for monitoring MG in aquatic system.

Protective effect of cilostazol on vascular injury in rats with acute ischemic stroke complicated with chronic renal failure

Sun Ru,Gu Qun,Zhang Xufeng,Zeng Ruiqi,Chen Dan,Yao Jingjing,Min Jingjing 한국독성학회 2024 Toxicological Research Vol.40 No.2

Chronic renal failure (CRF) resulting in vascular calcification, which does damage to blood vessels and endothelium, is an independent risk factor for stroke. It has been reported that cilostazol has a protective effect on the focal cerebral ischemic infarct. However, its impact on vascular injury in CRF combined stroke and its molecular protection mechanism have not been investigated. In this study, we carried out the effect of cilostazol on CRF combined stroke rats, and the results confirmed that it improved the neurobehavior, renal function as well as pathologic changes in both the kidney and brain. In addition, the inflammation and oxidative stress factors in the kidney and brain were suppressed. Moreover, the rates of brain edema and infarction were decreased. The injured brain-blood barrier (BBB) was recovered with less Evans blue extravasation and more expressions of zonula occludens-1(ZO-1) and occludin. More cerebral blood flow (CBF) in the ipsilateral hemisphere and more expression of CD31 and vascular endothelial growth factor (VEGF) in brain and kidney were found in the cilostazol group. Furthermore, cell apoptosis and cell autophagy became less, on the contrary, proteins of vascular endothelial growth factor receptor 2 (VEGFR2) after the cilostazol treatment were increased. More importantly, this protective effect is related to the pathway of Janus Kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), mammalian target of rapamycin (mTOR), and the hypoxia inducible factor-1α (HIF-1α). In conclusion, our results confirmed that cilostazol exerted a protective effect on the brain and kidney function, specifically in vascular injury, oxidative stress, cell apoptosis, cell autophagy, and inflammation response in CRF combined with stroke rats which were related to the upregulation of JAK/STAT3/mTOR signal pathway.

In Vitro and In Vivo Study on the Effect of Lysosome-associated Protein Transmembrane 4 Beta on the Progression of Breast Cancer

Deyou Tao,Junqing Liang,Yihong Pan,Yanting Zhou,Ying Feng,Lin Zhang,Jingjing Xu,Hui Wang,Ping He,Jie Yao,Yang Zhao,Qinjie Ning,Wen Wang,Wei Jiang,Jing Zheng,Xia Wu 한국유방암학회 2019 Journal of breast cancer Vol.22 No.3

Purpose: Although the effect of lysosome-associated protein transmembrane 4 beta (LAPTM4B) on the proliferation, migration, and invasion of breast cancer (BC) cells has already been studied, its specific role in BC progression is still elusive. Here, we evaluated the effect of different levels of LAPTM4B expression on the proliferation, invasion, adhesion, and tumor formation abilities of BC cells in vitro, as well as on breast tumor progression in vivo. Methods: We investigated the influence of LAPTM4B expression on MCF-7 cell proliferation, invasion, adhesion, and tube formation abilities in vitro through its overexpression or knockdown and on breast tumor progression in vivo. Results: Cell growth curves and colony formation assays showed that LAPTM4B promoted the proliferation of breast tumor cells. Cell cycle analysis results revealed that LAPTM4B promoted the entry of cells from the G1 into the S phase. Transwell invasion and cell extracellular matrix adhesion assays showed that LAPTM4B overexpression increased the invasion and adhesion capabilities of MCF-7 cells. More branches were observed in MCF-7 cells overexpressing LAPTM4B under an electron microscope. In comparison with LAPTM4B overexpression, LAPTM4B knockdown decreased the expression of vascular endothelial growth factor-A and significantly inhibited the vasculogenic tube formation ability of tumors. These results were also verified with western blot analysis. Conclusion: LAPTM4B promoted the proliferation of MCF-7 cells through the downregulation of p21 (WAF1/CIP1) and caspase-3, and induced cell invasion, adhesion, and angiogenesis through the upregulation of hypoxia-inducible factor 1 alpha, matrix metalloproteinase 2 (MMP2), and MMP9 expression. This specific role deems LAPTM4B as a potential therapeutic target for BC treatment.