Effects of Calcium Ion on Adenovirus Production with High Densities of HEK293 Cells

Xuping Liu,Liang Zhao,Yigang Wang,Xu Zhang,Wen-Song Tan 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.3

One of the major restrictions on the production of adenoviral vectors (AdV) is due to the decrease in virus concentration concomitant with an increase in cell concentration at infection (CCI) which is known as “cell density effect”, this could be because of the limited access to the nutrients or significant accumulation of toxic by-products. However, current strategies, such as developing robust serum-free medium and performing nutrient feeding, will partially address this issue. Therefore, the objective of this study was to further optimize serum-free culture medium by exploring the influence of calcium ion on virus production. Our studies showed that an optimal concentration of calcium ion significantly enhances AdV production,especially at a high CCI. During the virus infection process,a high concentration of calcium ion (≥ 1 mM) caused a reduction in virus infection efficiency, possibly as a result of cell aggregation. However, by optimizing the timing of the addition of calcium ion (i.e., 12 hours post-infection [hpi]), high virus infection efficiency could be maintained. The addition of 0.1 to 2 mM calcium ion at 12 hpi increased virus proliferation dose-dependently. Therefore,the optimal selection of both the concentration and the supplementation time of calcium ion during the process of AdV production could minimize the “cell density effect,”and a 2.6- and 3.2-fold increase in virus concentration could be achieved at CCI3 and CCI4, respectively.

SYNTHESIS OF CaWO 4 AND CaWO 4 :Eu MICROSPHERES BY PRECIPITATION

YUGUO YANG,XUPING WANG,BING LIU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.1

Nearly monodisperse CaWO 4 and CaWO 4 :Eu 3 þmicrospheres have been synthesized in largescale by a surfactant-assisted solution route, in which cetyltrimethyl ammonium bromide(CTAB) is used. X-ray di®raction (XRD), scanning electron microscopy (SEM), Fourier trans-form infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and photo-luminescence (PL) were used to characterize the resulting samples. The results of XRD indicatethat the CaWO 4 and CaWO 4 :Eu 3 þsamples have the scheelite structures. The growth process ofthese nearly monodisperse spheres with an average diameter around 3.2 ? m has been examined. The results of FTIR indicate that CTAB plays an important role in the formation of micro-spheres. The CaWO 4 microspheres exhibit a blue emission band with a maximum at 423 nm. Butthe CaWO 4 :Eu 3 þmicrospheres exhibit a red emission band with a maximum at 623 nm.

Temperature-Dependent Structural and Transport Properties of Liquid Transition Metals

Sui Yang,Xuping Su,Jianhua Wang,Nai-Yong Tang 대한금속·재료학회 2010 METALS AND MATERIALS International Vol.16 No.6

The evolution of the atomic structures and diffusivity of liquid transition metals with increasing temperature has been studied here using molecular dynamics. An analysis of Honeycutt and Andersen (HA) Indices indicates that relatively low order atomic clusters of rhombohedra-related structures increase with an increase in temperature. The results illustrate that the distortion in the local structural order with a predominant rhombohedra character enhances the diffusivity in liquid metals. The excess entropy approximated by the two-body contribution increases with the distortion of the local structural order traced by the HA Indices. The relationship between the excess entropy and the reduced diffusion coefficient supports the universal scaling law proposed by M. Dzugutov. The calculated diffusivities were compared with predictions of four diffusion models. The temperature dependence of the diffusivity cannot be described by the Arrhenius Law, the moving oscillator model or the free volume model but rather by the density fluctuation model with the square proportionality of temperature.

Screening of Plant Growth Promoting Rhizobacteria (PGPR) using a Promoter Capture System

Yeji Jeon,Minjeong Park,Xuping Zhao,Che Ok Jeon 한국생물공학회 2007 한국생물공학회 학술대회 Vol.2007 No.10

Analysis of the factors affecting the accuracy of detection for single base alterations by oligonucleotide microarray

Sanzhen Liu,Yao Li,Xuping Fu,Minyan Qiu,Bin Jiang,H ai W u,Rongyu Li,Yumin Mao,Yi Xie 생화학분자생물학회 2005 Experimental and molecular medicine Vol.37 No.2

The oligonucleotide microarray, a high-throughput polymorphism detection technology, holds great promise for the characterization of complex genetic variance. To achieve greater sensitivity and specificity for it to be an effective platform technology we present results and discuss some of the factors influencing signal intensities and single-mismatch discrimination in array-based mutation/SNP detection. Probes with a series of concentrations were spotted onto the slide in order to find the optimal concentration with the identifiable satisfying signals and the stable ratios between matched and mismatched probes. It was found that under our experimental conditions, when the initial probe concentration is higher than the maximum immobilization capability of the slide (7.5 µM), the hybridization signal will be saturated and the ratio between matched and mismatched probes will be more stable than at a lower probe concen-tration. Considering the cost of probes and the systematic stability, a constant spotting cone n-tration of 10 µM was selected. The stability of different types of mismatched oligo-DNA du-plexes on the glass surface was also confirmed. The results show that the order of stability of mismatched oligo-DNA duplexes on a glass surface is in general agreement with previous reports conducted using liquid and polyacryl-amide gel pads. This suggests that the influence of the mismatched base pair on the stability of the duplex in a solid hybridization system is similar to that in the solution hybridization environment.

Determining a Detectable Threshold of Signal Intensity in cDNA Microarray Based on Accumulated Distribution

Gao, Xia,Fu, Xuping,Li, Tao,Zi, Jian,Luo, Yao,Wei, Qing,Zeng, Erliang,Xie, Yi,Li, Yao,Mao, Yumin 생화학분자생물학회 2003 Journal of biochemistry and molecular biology Vol.36 No.6

In microarray data mining, one of the key problems is how to handle weak signals. Based on a bent piecewise linear accumulated distribution generally found in the microarray data, a new detectable threshold finding method is proposed to filter genes with unreliable information in this paper. More reliable and reproducible data is produced for the subsequent data mining.

Effects of Light Intensity on Components and Topographical Structures of Extracellular Polysaccharides from the Cyanobacteria Nostoc sp.

Hongmei Ge,Ling Xia,Xuping Zhou,Delu Zhang,Chunxiang Hu 한국미생물학회 2014 The journal of microbiology Vol.52 No.2

A study on the effects of light intensity (40 and 80 μE/m2/sec)on the components and topographical structures of extracellularpolysaccharides (EPS) was carried out in cyanobacteriaNostoc sp.. EPS yield increased with light intensity. However, light intensity did not significantly affect the EPSfractions and monosaccharide composition. Higher lightintensity generally resulted in higher protein content of EPSin similar fractions. The topographical structure of EPS, investigatedby atomic force microscopy, appeared as sphericallumps, chains and networks. The long chains were observedat higher light intensity. Thus, light intensity affected theyield and nature of EPS.

Preparation, Characterization and Luminescence Properties of a Novel 1,10-Phenanthroline-Functionalized Polyimide and Its Europium(III) Complexes

Zhiyong Chen,Jianjun Lu,Xuping Li,Xuting Jin,Lijuan Shi,Miaoqing Liu,Zhilin Sun 한국고분자학회 2015 Macromolecular Research Vol.23 No.9

A novel 1,10-phenanthroline-functionalized polyimide (CMPI-Phen) was prepared as polymer matrix by the nucleophilic substitution reaction between chloromethylated polyimide (CMPI) and 5-amino-1,10-phenanthroline (NH2-Phen). Then, two kinds of luminescent materials of 1,10-phenanthroline-functionalized polyimide containing Eu(III) complexes, were obtained by two different methods. Their structures and properties were characterized by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, inductively coupled plasma (ICP), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), luminescence spectrometry, and luminescence decay analysis. Investigations revealed that both the CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 display highly efficient red emissions, suggesting their potential application as luminescent materials. However, compared with CMPI-Phen-Eu(III), CMPI-Phen-Eu(TTA)3, where TTA stands for thenoyltrifluoroacetone, exhibits more excellent and stable fluorescence intensity and longer luminescence lifetime (134.30 μs). The weight-average molecular weights of CMPI-Phen-Eu(III) and CMPI-Phen- Eu(TTA)3 are 2.40×104 and 3.11×104, respectively. The Eu contents of CMPI-Phen-Eu(TTA)3 and CMPI-Phen-Eu(III) were measured by ICP to be 7.00% and 5.92%, respectively. TGA demonstrated that both CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 have high thermal stability and their 5% loss weight temperatures were 356 and 280 oC, respectively. Moreover, both CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 were soluble in polar solvents such as dimethylformamide (DMF), dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), and dimethylsulfoxide (DMSO) under heating conditions, and could be easily cast into tough thin films.

Qualitative Analysis of Switched Discrete-Time Descriptor Systems

Guisheng Zhai,Joe Imae,Xuping Xu,Tomoaki Kobayashi 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.4

In this paper, we consider stability analysis and design for switched systems consisting of linear discrete-time descriptor subsystems. When all descriptor subsystems are stable, we show that if the descriptor matrix and all the subsystem matrices are commutative pairwise, then the switched system is stable under arbitrary switching. We also extend the result to the case where all subsystems have different descriptor matrices. Under the same commutation condition, we show that in the case where none of the descriptor subsystems is stable, if there is a stable combination of the unstable descriptor subsystems, then we establish a class of switching laws which stabilize the switched descriptor system. All the results are natural but important extensions to the existing results for switched systems composed of state space subsystems.

Developing TCM clinical practice guidelines: A comparison between traditional Chinese medicine and western medicine

Xuan Yu,Shouyuan Wu,Juanjuan Zhang,Yue Hu,Meng Luo,Hongmei Zhao,Xuping Song,Yaolong Chen,Xiaohui Wang 한국한의학연구원 2023 Integrative Medicine Research Vol.12 No.2

Clinical practice guidelines in Traditional Chinese Medicine (CPG-TCM) is the recommendation that aims to provide the best service to users by identifying and summarizing the rules of prevention, diagnosis, treatment, rehabilitation, and regression of diseases based on systematic reviews of evidence and balancing the advantages and disadvantages of different interventions for clinical questions of Traditional Chinese Medicine. Over the past 30 years, the concept and methods of evidence-based medicine have had a significant impact on the development of clinical practice guidelines in Western Medicine (CPG-WM), and their standardized guideline development methods are being adapted and used in the development of CPG-TCM. However, the quality of CPG-TCM is far from CPG-WM, and the methodological system for developing CPG-TCM is not yet fully established. Therefore, this study aims to explore the methodological differences between CPG-TCM and CPG-WM and to inform the development of high-quality CPGTCM.