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      • Variation of Urinary and Serum Trace Elements (Ca, Zn, Cu, Se) in Bladder Carcinoma in China

        Guo, Kun-Feng,Zhang, Zhe,Wang, Jun-Yong,Gao, Sheng-Lin,Liu, Jiao,Zhan, Bo,Chen, Zhi-Peng,Kong, Chui-Ze Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

        Backgrounds: Deficiency or excess of trace elements can induce body metabolic disorders and cellular growth disturbance, even mutation and cancerization. Since there are few studies of the effect of trace elements in bladder carcinoma in China, the aim of this study was thus to assess variation using a case control approach. Methods: To determine this, 81 patients with bladder carcinoma chosen as a study group and 130 healthy persons chosen as a control group were all assayed for urinary and serum trace elements (calcium [Ca], zinc [Zn], copper [Cu], selenium [Se]) using an atomic absorption spectrophotometer, and the results were analyzed by independent sample t tests. The correlative factors on questionnaires answered by all persons were analyzed by logistic regression. Results: The results showed urinary Ca, Zn and serum Cu levels of the study group to be significantly higher (P<0.05) than those of he control group. Serum Ca and Se levels of study group were significantly lower (P<0.05) than those of control group. Conclusion: There were higher urinary Zn and serum Cu concentrations in bladder carcinoma cases. Bladder carcinoma may be associated with Ca metabolic disorder, leading to higher urinary Ca and lower serum Ca. Low serum Se and smoking appear to be other risk factors for bladder carcinoma in China.

      • SCIESCOPUSKCI등재

        Development of a position sensitive CsI(Tl) crystal array

        Shi, Guo-Zhu,Chen, Ruo-Fu,Chen, Kun,Shen, Ai-Hua,Zhang, Xiu-Ling,Chen, Jin-Da,Du, Cheng-Ming,Hu, Zheng-Guo,Fan, Guang-Wei Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.4

        A position-sensitive CsI(Tl) crystal array coupled with the multi-anode position sensitive photomultiplier tube (PS-PMT), Hamamatsu H8500C, has been developed at the Institute of Modern Physics. An effective, fast, and economical readout circuit based on discretized positioning circuit (DPC) bridge was designed for the 64-channel multi-anode flat panel PSPMT. The horizontal and vertical position resolutions are 0.58 mm and 0.63 mm respectively for the 1.0 × 1.0 × 5.0 ㎣ CsI(Tl) array, and the horizontal and vertical position resolutions are 0.86 mm and 0.80 mm respectively for the 2.0 × 2.0 × 10.0 ㎣ CsI(Tl) array. These results show that the CsI(Tl) crystal array with low cost could be applied in the fields of medical imaging and high-resolution gamma camera.

      • KCI등재

        Active control of a nonlinear and hysteretic building structure with time delay

        Kun Liu,Long-Xiang Chen,Guo-Ping Cai 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.3

        Time delay inevitably exists in active control systems, and it may cause the degradation of control efficiency or instability of the systems. So time delay needs to be compensated in control design in order to eliminate its negative effect on control efficiency. Today time delay in linear systems has been more studied and some treating methods had been worked out. However, there are few treating methods for time delay in nonlinear systems. In this paper, an active controller for a nonlinear and hysteretic building structure with time delay is studied. The nonlinear and hysteretic behavior of the system is illustrated by the Bouc-Wen model. By specific transformation and augmentation of state parameters, the motion equation of the system with explicit time delay is transformed into the standard state space representation without any explicit time delay. Then the fourth-order Runge-Kutta method and instantaneous optimal control method are applied to the controller design with time delay. Finally, numerical simulations and comparisons of an eight-story building using the proposed time-delay controller are carried out. Simulation results indicate that the control performance will deteriorate if time delay is not taken into account in the control design. The simulations also prove the proposed time delay controller in this paper can not only effectively compensate time delay to get better control effectiveness, but also work well with both small and large time delay problems.

      • SCIESCOPUSKCI등재

        Ginsengenin derivatives synthesized from 20(R)-panaxotriol: Synthesis, characterization, and antitumor activity targeting HIF-1 pathway

        Guo, Hong-Yan,Xing, Yue,Sun, Yu-Qiao,Liu, Can,Xu, Qian,Shang, Fan-Fan,Zhang, Run-Hui,Jin, Xue-Jun,Chen, Fener,Lee, Jung Joon,Kang, Dongzhou,Shen, Qing-Kun,Quan, Zhe-Shan The Korean Society of Ginseng 2022 Journal of Ginseng Research Vol.46 No.6

        Background: Ginseng possesses antitumor effects, and ginsenosides are considered to be one of its main active chemical components. Ginsenosides can further be hydrolyzed to generate secondary saponins, and 20(R)-panaxotriol is an important sapogenin of ginsenosides. We aimed to synthesize a new ginsengenin derivative from 20(R)-panaxotriol and investigate its antitumor activity in vivo and in vitro. Methods: Here, 20(R)-panaxotriol was selected as a precursor and was modified into its derivatives. The new products were characterized by <sup>1</sup>H-NMR, <sup>13</sup>C-NMR and HR-MS and evaluated by molecular docking, MTT, luciferase reporter assay, western blotting, immunofluorescent staining, colony formation assay, EdU labeling and immunofluorescence, apoptosis assay, cells migration assay, transwell assay and in vivo antitumor activity assay. Results: The derivative with the best antitumor activity was identified as 6,12-dihydroxy-4,4,8,10,14-pentamethyl-17-(2,6,6-trimethyltetrahydro-2H-pyran-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl(tert-butoxycarbonyl)glycinate (A11). The focus of this research was on the antitumor activity of the derivatives. The efficacy of the derivative A11 (IC<sub>50</sub> < 0.3 µM) was more than 100 times higher than that of 20(R)- panaxotriol (IC<sub>50</sub> > 30 µM). In addition, A11 inhibited the protein expression and nuclear accumulation of the hypoxia-inducible factor HIF-1α in HeLa cells under hypoxic conditions in a dose-dependent manner. Moreover, A11 dose-dependently inhibited the proliferation, migration, and invasion of HeLa cells, while promoting their apoptosis. Notably, the inhibition by A11 was more significant than that by 20(R)-panaxotriol (p < 0.01) in vivo. Conclusion: To our knowledge, this is the first study to report the production of derivative A11 from 20(R)-panaxotriol and its superior antitumor activity compared to its precursor. Moreover, derivative A11 can be used to further study and develop novel antitumor drugs.

      • KCI등재

        Representing the Heat-to-Moisture Transport Efficiency in Stable Conditions: An Extension of Two Different Approaches

        Guo Xiaofeng,Yang Kun,Yang Wei,Zhao Long,Li Shenghai,Ding Baohong 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.4

        Using eddy-covariance turbulence measurements over a Tibetan glacier, we present a description of scalar turbulence characteristics in the stable boundary layer. Interesting behaviours are demonstrated in terms of temperature–humidity de-correlation and dissimilarity. That is, a lack of perfect correlation occurs between the two scalars (i.e., correlation coefficients <1 in magnitude); overall, sensible heat is more efficiently transported than water vapour over snow and ice surfaces. Such behaviours provide evidence of departures from the idealized expectation of Monin–Obukhov similarity theory—all scalars assume a perfect level of linear correlation and an equal efficiency level of vertical transport. Results presented herein are noteworthy in that observations over uniform glaciated surfaces involve negligible effects of either a canopy-induced roughness sublayer or heterogeneity in the temperature–humidity source/sink distributions. Moreover, we address two different approaches to representing the heat-to-moisture transport efficiency in stable conditions. A new approach is extended through application of the quadrant analysis technique, thereby representing it as a function of atmospheric stability. Caution is further advised in the use of this approach, when temperature–humidity turbulence becomes markedly de-correlated. A second approach, as previously applied for estimating forest evaporation fluxes in unstable conditions, is extended to a stable boundary layer over snow and ice surfaces.

      • SCOPUS

        An Empirical Analysis of Sino-Russia Foreign Trade Turnover Time Series: Based on EMD-LSTM Model

        GUO, Jian,WU, Kai Kun,YE, Lyu,CHENG, Shi Chao,LIU, Wen Jing,YANG, Jing Ying Korea Distribution Science Association 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.10

        The time series of foreign trade turnover is complex and variable and contains linear and nonlinear information. This paper proposes preprocessing the dataset by the EMD algorithm and combining the linear prediction advantage of the SARIMA model with the nonlinear prediction advantage of the EMD-LSTM model to construct the SARIMA-EMD-LSTM hybrid model by the weight assignment method. The forecast performance of the single models is compared with that of the hybrid models by using MAPE and RMSE metrics. Furthermore, it is confirmed that the weight assignment approach can benefit from the hybrid models. The results show that the SARIMA model can capture the fluctuation pattern of the time series, but it cannot effectively predict the sudden drop in foreign trade turnover caused by special reasons and has the lowest accuracy in long-term forecasting. The EMD-LSTM model successfully resolves the hysteresis phenomenon and has the highest forecast accuracy of all models, with a MAPE of 7.4304%. Therefore, it can be effectively used to forecast the Sino-Russia foreign trade turnover time series post-epidemic. Hybrid models cannot take advantage of SARIMA linear and LSTM nonlinear forecasting, so weight assignment is not the best method to construct hybrid models.

      • SCIESCOPUSKCI등재

        A Novel Strategy for Thermostability Improvement of Trypsin Based on N-Glycosylation within the Ω-Loop Region

        Guo, Chao,Liu, Ye,Yu, Haoran,Du, Kun,Gan, Yiru,Huang, He The Korean Society for Microbiology and Biotechnol 2016 Journal of microbiology and biotechnology Vol.26 No.7

        The Ω-loop is a nonregular and flexible structure that plays an important role in molecular recognition, protein folding, and thermostability. In the present study, molecular dynamics simulation was carried out to assess the molecular stability and flexibility profile of the porcine trypsin structures. Two Ω-Loops (fragment 57-67 and fragment 78-91) were confirmed to represent the flexible region. Subsequently, glycosylation site-directed mutations (A73S, N84S, and R104S) were introduced within the Ω-loop region and its wing chain based on its potential N-glycosylation sites (Asn-Xaa-Ser/Thr consensus sequences) and structure information to improve the thermostability of trypsin. The result demonstrated that the half-life of the N84S mutant at 50℃ increased by 177.89 min when compared with that of the wild-type enzyme. Furthermore, the significant increase in the thermal stability of the N84S mutant has also been proven by an increase in the T<sub>m</sub> values determined by circular dichroism. Additionally, the optimum temperatures of the wild-type enzyme and the N84S mutant were 75℃ and 80℃, respectively. In conclusion, we obtained the thermostability-improved enzyme N84S mutant, and the strategy used to design this mutant based on its structural information and N-linked glycosylation modification could be applied to engineer other enzymes to meet the needs of the biotechnological industry.

      • KCI등재

        Dual-Responsive Shape Memory and Thermally Reconfigurable Reduced Graphene Oxide-Vitrimer Composites

        Guo-kang Chen,Kun Wu,Qian Zhang,Yan-cen Shi,Man-geng Lu 한국고분자학회 2019 Macromolecular Research Vol.27 No.6

        In this paper, we have prepared shape memory reduced graphene oxidevitrimer composites via in situ reduction of graphene oxide (GO) during the curing reaction. Because of good compatibility between GO and epoxy resin, reduced graphene oxide (rGO) has a good dispersion in the epoxy matrix. Conventional thermoset shape memory polymers can only maintain one permanent shape, while these obtained composites can be randomly reconfigured into other shapes via dynamic covalent transesterification reaction at 200 °C above transesterification temperature (TV). They can recover quickly from fixed shapes to their initial shapes with shape fixity ratio higher than 95% and shape recovery ratio higher than 97%. Besides, the rGO-vitrimers show good mechanical properties and thermal stabilities. In addition, sequent nearinfrared (NIR) irradiation can control the shape recovery, because rGO can serve as an energy convertor to convert NIR irradiation into thermal energy.

      • KCI등재

        Molecular cloning and characterization of biphenyl hydrolase-like (BPHL) protein gene from silkworm, Bombyx mori

        Kun Gao,Xiang Yuan Deng,Meng Ke Shang,Heying Qian,Xijie Guo 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.3

        The cDNA of a biphenyl hydrolase-like (BPHL) protein from Bombyx mori was cloned via rapid amplification of cDNA ends and submitted to GenBank under accession number JN020647. The full-length BmBPHL cDNA was 1161 bp, with four exons and three introns. It consisted of a 208 bp 5′-terminal untranslated region (UTR) and a 191 bp 3′-UTR with three polyadenylation signal sequences AATAAA and a poly(A) tail. The BmBPHL cDNA encodes a 253–amino acid polypeptide with a theoretical isoelectric point of 8.67 and a predicted molecular weight of 28.9 kDa. The deduced amino acid sequence of BmBPHL contained an abhydrolase_6 domain and the Gly-X-Ser-X-Gly motif that is characteristic of serine hydrolases. Sequence comparison showed that BmBPHL is 51% identical to Tribolium castaneum BPHL and 50% identical to Nasonia vitripennis BPHL. Phylogenetic analysis revealed that BmBPHL is grouped with insect BPHL proteins, separating from vertebrate BPHLs. The BmBPHL mRNA transcripts were mainly detected in hemolymph and fat body using fluorescent quantitative real-time PCR. In addition, infectionwith B. mori cytoplasmic polyhedrosis virus (BmCPV) upregulated the relative BmBPHL expression in the hemolymph and midgut. Therefore, BmBPHL may have an important function in the response of silkworms to BmCPV infection.

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