Chromatographic Behavior of Proteins on Stationary Phase with Aminocarboxy Ligand

Rong Li,Ming-Yang Ju,Bin Chen,Qing-Yuan Sun,Guo-Liang Chen,Mei Shi,Xiao-Gang Wang,Jian-Bin Zheng 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

An aminocarboxy aspartic acid-bonded silica (Asp-Silica) stationary phase was synthesized using L-aspartic acid as ligand and silica gel as matrix. The standard protein mixtures were separated with prepared chromatographic column. The effects of solution pH, salt concentration and metal ion on the retention of proteins were examined, and also compared with traditional iminodiacetic acid-bonded silica (IDA-Silica) column. The results show that Asp-Silica column exhibited an excellent separation performance for proteins. The retention of proteins on Asp-Silica stationary phase was consistent with electrostatic characteristic of cation-exchange. The stationary phase displayed typical metal chelate property after fixing copper ion (II) on Asp-Silica. Under competitive eluting condition, protein mixtures were effectively isolated. Asp ligand showed better ion-exchange and metal chelating properties as compared with IDA ligand.

Synthesis and Chromatographic Characteristics of Multidentate Ligand-Boned Silica Stationary Phases

Rong Li,Yan Wang,Guo-Liang Chen,Mei Shi,Xiao-Gang Wang,Jian-Bin Zheng 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.8

To improve the separation property and stability of metal chelate Cu(II) column, three new kinds of multidentate aminocarboxy silica columns with cation-exchange properties were synthesized using glutamic acid (Glu), glutamic acidbromoacetic acid (Glu-BAA), glutamic acid-bromosuccinic acid (Glu-BSUA) as ligands and silica gel as matrix. The standard proteins were separated with prepared chromatographic columns. The stationary phases exhibited the metal chelate property after fixing copper ion (II) on the synthesized multidentate ligand silica columns. The binding capacity of immobilized metal ion was related with the dentate number of multidentate ligands. Chromatographic behavior of proteins and the leakage of immobilized metal ion on multidentate chelate Cu(II) columns were affected by the dentate number of multidentate ligands and competitive elution system directly. The results showed that quinquedentate Glu-BSUA-Cu(II) column exhibited better chromatographic property and stability as compared with tridentate Glu-Cu(II) column, tetradentate Glu-BAA-Cu(II) column and commonly used IDA-Cu(II) column.

miR-340 Reverses Cisplatin Resistance of Hepatocellular Carcinoma Cell Lines by Targeting Nrf2-dependent Antioxidant Pathway

Shi, Liang,Chen, Zhan-Guo,Wu, Li-li,Zheng, Jian-Jian,Yang, Jian-Rong,Chen, Xiao-Fei,Chen, Zeng-Qiang,Liu, Cun-Li,Chi, Sheng-Ying,Zheng, Jia-Ying,Huang, Hai-Xia,Lin, Xiang-Yang,Zheng, Fang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Many chemotherapeutic agents have been successfully used to treat hepatocellular carcinoma (HCC); however, the development of chemoresistance in liver cancer cells usually results in a relapse and worsening of prognosis. It has been demonstrated that DNA methylation and histone modification play crucial roles in chemotherapy resistance. Currently, extensive research has shown that there is another potential mechanism of gene expression control, which is mediated through the function of short noncoding RNAs, especially for microRNAs (miRNAs), but little is known about their roles in cancer cell drug resistance. In present study, by taking advantage of miRNA effects on the resistance of human hepatocellular carcinoma cells line to cisplatin, it has been demonstrated that miR-340 were significantly downregulated whereas Nrf2 was upregulated in HepG2/CDDP (cisplatin) cells, compared with parental HepG2 cells. Bioinformatics analysis and luciferase assays of Nrf2-3'-untranslated region-based reporter constructor indicated that Nrf2 was the direct target gene of miR-340, miR-340 mimics suppressing Nrf2-dependent antioxidant pathway and enhancing the sensitivity of HepG2/CDDP cells to cisplatin. Interestingly, transfection with miR-340 mimics combined with miR-340 inhibitors reactivated the Nrf2 related pathway and restored the resistance of HepG2/CDDP cells to CDDP. Collectively, the results first suggested that lower expression of miR-340 is involved in the development of CDDP resistance in hepatocellular carcinoma cell line, at least partly due to regulating Nrf2-dependent antioxidant pathway.

An Improved and Efficient Analytical Model for Magnetic Field Calculation in Linear Permanent Magnet Machines

Baocheng Guo,Rong Guo,Hengzai Hu,Jianping Shi,Chunmei Feng 한국자기학회 2022 Journal of Magnetics Vol.27 No.1

A simple and improved analytical model (AM) for linear permanent magnet synchronous machine (LPMSM) based on the correction factor is presented in this paper. A slotless linear permanent magnet machine (PLPM) with AM developed in Cartesian coordinate is selected to investigate. Consequently, the fitting equations of curvature factors for the permanent magnet and armature are obtained. The subdomains for LPMSM are simplified from 6 down to 3 domains based on curvature equations. The magnetic flux density and force show that the proposed approach agrees with the finite element (FE) model. Moreover, the reduced calculation domains and harmonic orders make AM proposed in the paper much faster. The main contribution of the work is to present a simple strategy for coordinate transformation and calculation strategy for LPMSM, which provides guideline for designers to investigate the machines developed in Cartesian coordinate.

Process of Equiaxed Grains of RE-Al Alloy under Slope Vibration

Xie Shi-kun,Yi Rong-xi,Pan Xiao-liang,Zheng Xiao-qiu,Guo Xiu-yan 한국소성가공학회 2010 기타자료 Vol.2010 No.6

A new technique using slope vibration casting process during heating and isothermal holding period to prepare Al-7Si-2RE alloy has been studied. The small, near-spherical and non-dendritic microstructure with the semi-solid processing requirements has been obtained. Experiments show that the cooling method, pouring process and the convection of melt caused by slope vibration had significant effects on the formation of near-spherical primary gains. The water-cooled copper mold casting with slope vibration at the temperature near liquidus can obtain Al-7Si-2RE alloy with small homogeneous equiaxed grains, the average grain diameter is 48.3μm, and the average grain roundness is 1.92.

Value of PAX1 Methylation Analysis by MS-HRM in the Triage of Atypical Squamous Cells of Undetermined Significance

Li, Shi-Rong,Wang, Zhen-Ming,Wang, Yu-Hui,Wang, Xi-Bo,Zhao, Jian-Qiang,Xue, Hai-Bin,Jiang, Fu-Guo Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.14

Background: Detection of cervical high grade lesions in patients with atypical squamous cells of undetermined significance (ASCUS) is still a challenge. Our study tested the efficacy of the paired boxed gene 1 (PAX1) methylation analysis by methylation-sensitive high-resolution melting (MS-HRM) in the detection of high grade lesions in ASCUS and compared performance with the hybrid capture 2 (HC2) human papillomavirus (HPV) test. Materials and Methods: A total of 463 consecutive ASCUS women from primary screening were selected. Their cervical scrapings were collected and assessed by PAX1 methylation analysis (MS-HRM) and high-risk HPV-DNA test (HC2). All patients with ASCUS were admitted to colposcopy and cervical biopsies. The Chisquare test was used to test the differences of PAX1 methylation or HPV infection between groups. Results: The specificity, sensitivity, and accuracy for detecting CIN2 + lesions were: 95.6%, 82.4%, and 94.6%, respectively, for the PAX1 MS-HRM test; and 59.7%, 64.7%, and 60.0% for the HC2 HPV test. Conclusions: The PAX1 methylation analysis by MS-HRM demonstrated a better performance than the high-risk HPV-DNA test for the detection of high grade lesions (CIN2 +) in ASCUS cases. This approach could screen out the majority of low grade cases of ASCUS, and thus reduce the referral rate to colposcopy.

Synthesis and Chromatographic Characteristics of Multidentate Ligand-Boned Silica Stationary Phases

Li, Rong,Wang, Yan,Chen, Guo-Liang,Shi, Mei,Wang, Xiao-Gang,Zheng, Jian-Bin Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.8

To improve the separation property and stability of metal chelate Cu(II) column, three new kinds of multidentate aminocarboxy silica columns with cation-exchange properties were synthesized using glutamic acid (Glu), glutamic acidbromoacetic acid (Glu-BAA), glutamic acid-bromosuccinic acid (Glu-BSUA) as ligands and silica gel as matrix. The standard proteins were separated with prepared chromatographic columns. The stationary phases exhibited the metal chelate property after fixing copper ion (II) on the synthesized multidentate ligand silica columns. The binding capacity of immobilized metal ion was related with the dentate number of multidentate ligands. Chromatographic behavior of proteins and the leakage of immobilized metal ion on multidentate chelate Cu(II) columns were affected by the dentate number of multidentate ligands and competitive elution system directly. The results showed that quinquedentate Glu-BSUA-Cu(II) column exhibited better chromatographic property and stability as compared with tridentate Glu-Cu(II) column, tetradentate Glu-BAA-Cu(II) column and commonly used IDA-Cu(II) column.

Chromatographic Behavior of Proteins on Stationary Phase with Aminocarboxy Ligand

Li, Rong,Ju, Ming-Yang,Chen, Bin,Sun, Qing-Yuan,Chen, Guo-Liang,Shi, Mei,Wang, Xiao-Gang,Zheng, Jian-Bin Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

An aminocarboxy aspartic acid-bonded silica (Asp-Silica) stationary phase was synthesized using L-aspartic acid as ligand and silica gel as matrix. The standard protein mixtures were separated with prepared chromatographic column. The effects of solution pH, salt concentration and metal ion on the retention of proteins were examined, and also compared with traditional iminodiacetic acid-bonded silica (IDA-Silica) column. The results show that Asp-Silica column exhibited an excellent separation performance for proteins. The retention of proteins on Asp-Silica stationary phase was consistent with electrostatic characteristic of cation-exchange. The stationary phase displayed typical metal chelate property after fixing copper ion (II) on Asp-Silica. Under competitive eluting condition, protein mixtures were effectively isolated. Asp ligand showed better ion-exchange and metal chelating properties as compared with IDA ligand.

Preparation and characteristics of carboplatin-Fe@C-loaded chitosan nanoparticles with dual physical drug-loaded mechanisms

Yue-Hua Guo,Fu-Rong Li,Shi-Yun Bao,Tao Han,Jun-Jian Cao,Han-Xin Zhou 한국물리학회 2007 Current Applied Physics Vol.7 No.s1

The present work is intended to set up the optimal carboplatin-Fe@C-loaded chitosan nanoparticles method and to compare andassess carboplatin-Fe@C-loaded with carboplatin-Fe-loaded chitosan nanoparticles. Both kinds of nanoparticles were prepared by areverse microemulsion method. The carboplatin-Fe@C-loaded chitosan nanoparticles consisted of Fe@C nanopowder with the adsorbeddrug as the magnetic core, chitosan as the matrix and carboplatin as the model drug. The core of the carboplatin-Fe-loaded chitosannanoparticles was pure iron nanopowder, which was unable to adsorb a drug. The characteristics of both kinds of nanoparticles weredetermined and compared. The results showed that both kinds of nanoparticles were spherical in shape with an average size of210 nm ± 26 nm (size range 150300 nm) and a good magnetic responsivity. The drug content of the nanoparticles wasrespectively. The cumulative release percentages of carboplatin-Fe@C-loaded chitosan nanoparticles in vitro in 1d, 2d, 3d, 4d were60%, 74%, 84%, and 92%, respectively, and those of carboplatin-Fe-loaded chitosan nanoparticles in 1d, 2d were 81% and 91%. Thus,the carboplatin-Fe@C-loaded chitosan nanoparticles with dual physical drug-loaded mechanisms (physical encapsulation and adsorp-tion of active carbon) possessed a higher drug content and showed more sustained releasing. The cooperation of multiple mechanismswas a promising feature to improve the properties of nanoparticles.

Resistance of Cucumber Grafting Rootstock Pumpkin Cultivars to Chilling and Salinity Stresses

Yang Xu,Shi-rong Guo,He Li,Hong-zhu Sun,Na Lu,Sheng Shu,Jin Sun 한국원예학회 2017 원예과학기술지 Vol.35 No.2

Grafting using a pumpkin (Cucurbita sp.) rootstock is an effective way to improve cucumber (Cucumis sativus ) resistance to a combination of chilling and salinity stresses. We evaluated the tolerance of 15 pumpkin cultivars to chilling, salinity, and combined stresses at the germination and seedling stages. Selected plant characteristics, including germination rate, germination potential, germination index, plant height, stem thickness, fresh weight, and dry weight, were analyzed. We used the unweighted pair group method with arithmetic mean for cluster analyses to determine the stress tolerance levels of the pumpkin cultivars. The 15 cultivars were divided into three clusters: tolerant, moderately tolerant, and susceptible to stress treatments. The stress tolerances of all cultivars were variable in the germination and seedling stages, and most cultivars were not tolerant to individual treatments of chilling or salinity stresses at both stages. These results suggest that identifying suitable cultivars for use as rootstock during cucumber grafting should involve the evaluation of stress tolerance during different growth stages. Additionally, cultivars tolerant to chilling stress may not be tolerant to salinity stress; therefore, the choice of pumpkin rootstock should depend on where the grafted plant will be grown. Cultivars tolerant to a combination of chilling and salinity stresses may be useful as rootstock for cucumber grafting. Our findings may serve as reference material for choosing appropriate pumpkin rootstocks for cucumber grafting.