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      • KCI등재

        Saroclazines A–C, thio-diketopiperazines from mangrove-derived fungi Sarocladium kiliense HDN11-84

        Feng Li,Wenqiang Guo,Li Wu,Tian-jiao Zhu,Qian Qun Gu,De-Hai Li,Qian Che 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.1

        Three new diketopiperazine derivatives (DKPs), saroclazines A–C (1–3) along with three known DKPs (4– 6) were isolated from mangrove-derived fungi Sarocladium kiliense HDN11-84. Saroclazines A–B (1 and 2) possessed a free amide structure, which was first found in sulfurcontaining aromatic DKPs. Their structures were elucidated by NMR, HRESIMS and X-ray. The cytotoxic activity of new compounds (1–3) was tested against HeLa cell lines, among which compound 2 showed an IC50 value of 4.2 lM.

      • Cloning and Characterization of a PI-like MADS-Box Gene in Phalaenopsis Orchid

        Guo, Bin,Hexige, Saiyin,Zhang, Tian,Pittman, Jon K.,Chen, Donghong,Ming, Feng Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.6

        The highly evolved flowers of orchids have colorful sepals and fused columns that offer an opportunity to discover new genes involved in floral development in monocotyledon species. In this investigation, we cloned and characterized the homologous PISTALLATA-like (PI-like) gene PhPI15 ($\underline{Ph}alaenopsis$ $\underline{PI}$ STILLATA # $\underline{15}$), from the Phalaenopsis hybrid cultivar. The protein sequence encoded by PhPI15 contains a typical PI-motif. Its sequence also formed a subclade with other monocot PI-type genes in phylogenetic analysis. Southern analysis showed that PhPI15 was present in the Phalaenopsis orchid genome as a single copy. Furthermore, it was expressed in all the whorls of the Phalaenopsis flower, while no expression was detected in vegetative organs. The flowers of transgenic tobacco plants ectopically expressing PhPI15 showed male-sterile phenotypes. Thus, as a Class-B MADS-box gene, PhPI15 specifies floral organ identity in orchids.

      • KCI등재

        Quantitative evaluation method for machining accuracy retention of CNC machine tools considering degenerate trajectory fluctuation

        Cong Feng,Zhaojun Yang,Chuanhai Chen,Jinyan Guo,Hailong Tian,Fanning Meng 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

        Accuracy retention is an important performance index of CNC machine tools. At present, research on the evaluation of machining accuracy retention of CNC machine tools mainly focuses on accuracy value of a fixed time point or different time periods, but studies on the fluctuation degree of degradation trajectory related to time change are limited. Extracting simple and effective degradation characteristics of machining accuracy and then evaluating machining accuracy retention considering fluctuation of degradation trajectory are necessary. The volume error model of CNC machine tools is established on the basis of multibody system theory in this study. Three-dimensional volume error vector is transformed into one-dimensional machining accuracy degradation by calculating offset distance between spatial error and origin points. Degradation data obtained via regular measurement and calculation are used to establish the complete degradation trajectory model of the CNC machine tools machining accuracy using radial basis function interpolation method according to the fluctuation degree of degradation trajectory, and concepts of average degradation rate and average degradation amount are defined. Lastly, examples showed that these two indicators can intuitively reflect fluctuation degree of machining accuracy degradation of CNC machine tools and effectively and quantitatively evaluate accuracy retention of CNC machine tools. The quantitative evaluation method of accuracy retention of CNC machine tools defined in this study considers the fluctuation degree of accuracy degradation trajectory. The quantitative evaluation index of accuracy retention demonstrates satisfactory engineering application because it can reflect not only the accuracy change of a single machine tool but also accurately compare the accuracy retention between different machine tools.

      • SCIESCOPUSKCI등재
      • On-line Drift Reduction for Portable Electronic Nose Instrument in Monitoring Indoor Formaldehyde

        Jingwei Feng,Fengchun Tian,Bo Hu,Qi Ye,Bo Xiao,Jielian Guo 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

        In this paper, a new on-line drift reduction method based on component correction method is proposed for using in a portable electronic nose (Enose) instrument which is used for real-time monitoring indoor formaldehyde. For a portable Enose instrument which is used indoors, the external conditions are changed from time to time, so the drift direction cannot be easily obtained by using component correction method. Support vector machines (SVM) is used for predicting baseline of each sensor in portable Enose instrument. According baseline prediction and correction, the drift direction is obtained, and reduced by using component correction. And then, another SVM is used for predicting the concentration of formaldehyde. The results show that the method works efficiently for a portable Enose instrument which is used for real-time monitoring indoor formaldehyde.

      • Apoptotic Effects of psiRNA-STAT3 on 4T1 Breast Cancer Cells in Vitro

        Zhou, Yue,Tian, Lin,Zhang, Ying-Chao,Guo, Bao-Feng,Zhou, Qing-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

        Background: The aim of this study was to investigate the effect of a Lipofectamine2000 (Life2000) Transfection Reagent transfected psiRNA-STAT3 plasmid on 4T1 breast cancer cells. Materials and Methods: MTT was used to detect the cell proliferation of breast cancer 4T1 cells at different periods (0h, 6h, 8h, 10h); the cell cycle was assessed by flow cytometry; variation of apoptosis and mitochondrial membrane potential was observed under a fluorescence microscope; immunohistochemical staining was used to determine the expression of caspase-3 and cyclin-D1 protein. Results: An obvious effect of inhibition to 4T1 cancer cells could be observed at 8h after the psiRNA-STAT3 was transfected. Typical alterations of apoptotic morphological features were visible in the psiRNA-STAT3 treatment group. Mitochondrial membrane potential decreased significantly, the number of cells was increased in G0/G1 phase, and the number of cells was decreased in S phase, and the data were statistically significant (p<0.05), compared with the Scramble and Mock groups. Expression of caspase-3 protein was increased significantly, while that of cyclin D1 was significantly decreased. Conclusions: Life2000 transfected psiRNA-STAT3 plasmid can inhibit 4T1 tumor cell proliferation and promote apoptosis of 4T1 tumor cells, which process depends on the regulation of expression of cyclin D1 and caspase-3 protein.

      • KCI등재

        Effect of metallic precursors on the thin film thickness and reaction resistances in the selenization process

        Wei Liu,Jian-Guo Tian,Qing He,Feng-Yan Li,Chang-Jian Li,Yun Sun 한국물리학회 2011 Current Applied Physics Vol.11 No.3

        In the selenization process, the sputtered metallic precursors transformed into CIGS thin films, which were investigated by novel in-situ resistance measurement. Simultaneously, the crystal phases and thicknesses of the selenized thin films at various selenization temperatures are obtained by XRD and XRF,respectively. According to the analysis of phase evolutions and reaction characteristics, it can be confirmed metallic In existed in the precursors will transform into the In―Se compound directly and then results in CIS formation as well as the thickness increase below 370 ℃. Otherwise, if alloy phases Cu ―In and Cu―Ga co-exist in the precursors, not CIS but CIGS will form above 470°, which will lead to both thickness and resistance increase in the corresponding temperature range. Consequently, it can be concluded the thickness increase are decided by the formation of CIS or CIGS, whereas the strong reaction peak in the temperature-resistance curves are caused only by stoichiometric CIGS.

      • KCI등재후보

        Age-induced Changes in Ginsenoside Accumulation and Primary Metabolic Characteristics of Panax Ginseng in Transplantation Mode

        Wei Yuan,Qing-feng Wang,Wen-han Pei,Si-yu Li,Tian-min Wang,Hui-peng Song,Dan Teng,Ting-guo Kang,Hui Zhang 고려인삼학회 2024 Journal of Ginseng Research Vol.48 No.1

        Background: Ginseng (Panax ginseng Mayer) is an important natural medicine. However, a long culture period andchallenging quality control requirements limit its further use. Although artificial cultivation can yield a sustainablemedicinal supply, research on the association between the transplantation and chaining of metabolicnetworks, especially the regulation of ginsenoside biosynthetic pathways, is limited. Methods: Herein, we performed Liquid chromatography tandem mass spectrometry based metabolomic measurementsto evaluate ginsenoside accumulation and categorise differentially abundant metabolites (DAMs). Transcriptome measurements using an Illumina Platform were then conducted to probe the landscape of geneticalterations in ginseng at various ages in transplantation mode. Using pathway data and crosstalk DAMs obtainedby MapMan, we constructed a metabolic profile of transplantation Ginseng. Results: Accumulation of active ingredients was not obvious during the first 4 years (in the field), but followingtransplantation, the ginsenoside content increased significantly from 6 8 years (in the wild). Glycerolipidmetabolism and Glycerophospholipid metabolism were the most significant metabolic pathways, as Lipids andlipid-like molecule affected the yield of ginsenosides. Starch and sucrose were the most active metabolic pathwaysduring transplantation Ginseng growth. Conclusion: This study expands our understanding of metabolic network features and the accumulation of specificcompounds during different growth stages of this perennial herbaceous plant when growing in transplantationmode. The findings provide a basis for selecting the optimal transplanting time.

      • KCI등재

        Active Compounds from Schisandra chinensis Exhibiting Tyrosinase Activity and Melanin Content Inhibition in B16 Melanoma Cells

        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.

      • KCI등재

        Composite Nanofibers by Growing Polypyrrole on the Surface of Polyaniline Nanofibers Formed under Free Melting Condition and Shell-Thickness-Dependent Capacitive Properties

        Banglei Liang,Yaqi Zhao,Xinxin Guo,Zhenxin Zhao,Qiao Feng,Jingyi Guo,Xiaoyuan Zhang,Jinyu Tian 한국섬유공학회 2020 Fibers and polymers Vol.21 No.8

        An efficient approach was presented to prepare polyaniline/polypyrrole (PANi/PPy) composite nanofibers bygrowing PPy layers on the surface of PANi nanofibrous seeds as electrode materials for supercapacitors in neutral electrolyte. Core layer of PANi nanofiber was firstly synthesized by the chemical oxidative polymerization of aniline monomers underfree melting condition of reaction solutions in fully aqueous system without the assistance of any templates or organicsolvents. Then the shell layer of PPy was fabricated by in-situ chemical oxidative polymerization of pyrrole monomers withthe above-mentioned PANi nanofiber as a seed, and the PPy shell layer thicknesses were tuned by changing the molar ratio ofaniline to pyrrole. The resulting PANi/PPy composites were investigated by field-emission scanning electron microscopy,ultraviolet-visible spectroscopy, Fourier transform infrared and Raman spectrometry. Furthermore, electrochemical behaviorsin Na2SO4 electrolyte were tested by cyclic voltammetry, galvanostatic charge-discharge techniques and electrochemicalimpedance spectroscopy. It turned out that low molar ratio of aniline to pyrrole is helpful to increase the PPy shell layerthicknesses, yield and conductivity of PANi/PPy composite nanofibers. A great improvement on the capacitive propertiescould be achieved by choosing appropriate PPy shell layer thickness. The results showed that benefiting from strong synergyeffect and π-π interaction between PANi core and PPy shell layer as well as low electrochemical impedance, PANi/PPycomposite nanofibers prepared with the molar ratio of 1:1 (PPy shell layer thickness of about 12.5 nm) displayed the highestspecific capacitance of 1550.2 F g-1 at scan rate of 5 mV s-1 and 758.8 F g-1 at the current density of 1 A g-1 with the bestcycling stability of 70.3 % after 500 cycles in 0.5 M Na2SO4 electrolyte, which exhibited a great potential in the developmentof high-performance electrode materials operated in environmentally friendly electrolyte.

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