Synthesis and Characterization of Poly(lactic acid-co-glycolic acid-co-ε-caprolactone) and Its Pressure Sensitive Adhesive Property

Minjian Cao,Zhean Xia,Xiangxin Ran,Jinglong Zou 한국고분자학회 2021 폴리머 Vol.45 No.4

Random copolymers of poly(lactic acid-co-glycolic acid-co-ε-caprolactone) (PLGA-CL) based on lactic acid (LA), glycolic acid (GA), citric acid (CA), and ε-caprolactone (CL) were synthesized and characterized. ¹H NMR spectra showed that the polymerization conversion of various monomers was high under the experimental conditions, and the degree of polymerization of the polycaprolactone (PCL) segment increased with the growth of CL content. The content of CL has a remarkable effect on the decrease of glass transition temperature (Tg) of the copolymers. The adhesive properties of random copolymers as pressure-sensitive adhesive (PSA) were evaluated. With the increase of CL content, 180° peel strength, the shear strength and loop tack decreased. When CL content was 16.7 wt%, 180° peel strength was 4.76 N/25 ㎜, and loop tack was 8.45 N/25 ㎜.

Evaluating Technical and Tactical Abilities of Football Teams in Euro 2012 Based on Improved Information Entropy Model and SOM Neural Networks

Minjian Wang 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.11

In this paper, improved information entropy model and SOM neural networks are proposed for evaluating technical and tactical abilities of football teams in Euro 2012.Information entropy model is an effective performance evaluation tool. As a fine clustering tool, SOM has been used widely. The approach make input space cluster automatically and the learning process of clustering doesn’t need supervision. At the same time, eleven indicators that reflect technical and tactical ability of football teams are selected. Then, by means of entropy method and clustering analysis with statistic data of Euro 2012, characteristic and law is discovered between competition results and technical and tactical abilities, and a method for comprehensive assessment of technical and tactical abilities of football teams was proposed.

Expression of Hepatitis B Virus S Gene in Pichia pastoris and Application of the Product for Detection of Anti-HBs Antibody

Hu, Bo,Liang, Minjian,Hong, Guoqiang,Li, Zhaoxia,Zhu, Zhenyu,Li, Lin Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.6

Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying ahexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5% of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100% with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent for HBsAb detection prepared by Pichia pastoris-derived S protein showed high sensitivity and specificity for detection of HBsAb standard. And a good correlation was obtained between the reagent produced by recombinant S protein and commercial kit produced by blood-origin HBsAg in random samples.

Compressive Deformation Behavior of AZ31Mg Alloy Containing {10–12} Extension Twins at Different Temperature

Hua Zhang,Xiaoqing Bai,Minjian Hou,Lifei Wang,Qiang Zhang,Jianfeng Fan,Weiguo Li,Hongbiao Dong,Bingshe Xu 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

Influence of pre-introducing {10–12} extension twins on compressive deformation behavior of AZ31Mg alloy at differenttemperature was investigated. The compression tests were conducted along the normal direction of AZ31Mg alloy at roomtemperature, 100 °C, 200 °C and 300 °C with a strain rate of 1 × 10−3 s−1. The results indicated that the pre-introducing{10–12} extension twins strongly affected the yield strength, the peak strength and the strain hardening rate at middle-lowtemperature (≤ 200 °C). The twinned samples containing pre-introducing {10–12} extension twins exhibited smaller yieldstrength and larger peak strength than the as-received samples without {10–12} extension twins at temperature ≤ 200 °C. Forthe as-received samples, the strain hardening rate decreased gradually at different temperature. While for the twinned samples,the strain hardening behavior exhibited three distinct stages at temperature ≤ 200 °C. When compressing at 300 °C, the asreceivedand twinned samples exhibited similar compression flow curves and strain hardening rate curves. The continuousdynamic recrystallization (CDRX) was the main dynamic recrystallization (DRX) mechanism in the as-received sample whencompressing at 200 °C. The twin assisted DRX besides CDRX was also initiated in the twinned sample when compressingat 200 °C. While the DRX mechanism was transformed into the discontinuous dynamic recrystallization (DDRX) in boththe as-received and twinned samples when compressing at 300 °C.

Authentication of an Endangered Herb Changium smyrnioides from Different Producing Areas Based on rDNA ITS Sequences and Allele- Specific PCR

Xiaoqin Sun,Yueyu Hang,Yanglian Wei,Minjian Qin,Qiaosheng Guo,Jianlin Guo,Yifeng Zhou 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.4

The rDNA ITS region of 18 samples of Changium smyrnioides from 7 areas and of 2 samples of Chuanminshen violaceum were sequenced and analyzed. The amplified ITS region of the samples, including a partial sequence of ITS1 and complete sequences of 5.8S and ITS2, had a total length of 555 bp. After complete alignment, there were 49 variable sites, of which 45 were informative,when gaps were treated as missing data. Samples of C. smyrnioides from different locations could be identified exactly based on the variable sites. The maximum parsimony (MP) and neighbor joining (NJ) tree constructed from the ITS sequences based on Kumar’s two-parameter model showed that the genetic distances of the C. smyrnioides samples from different locations were not always related to their geographical distances. A specific primer set for Allele-specific PCR authentication of C. violaceum from Jurong of Jiangsu was designed based on the SNP in the ITS sequence alignment. C. violaceum from the major genuine producing area in Jurong of Jiangsu could be identified exactly and quickly by Allele-specific PCR.

Determination of ginsenosides in Asian and American ginsengs by liquid chromatography-quadrupole/time-of-flight MS: assessing variations based on morphological characteristics

Chen, Yujie,Zhao, Zhongzhen,Chen, Hubiao,Brand, Eric,Yi, Tao,Qin, Minjian,Liang, Zhitao The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.1

Background: Asian ginseng and American ginseng are functional foods that share a close genetic relationship and are well-known worldwide. This article aims to investigate the correlation between morphological characteristics and the inherent quality of Asian and American ginsengs. Methods: In this study, an ultra-HPLC-quadrupole/time-of-flight MS (UHPLC-Q/TOF-MS) method was established for the quantitative analysis of 45 ginseng samples. The method developed for determination was precise and accurate. Results: The results showed that Asian ginseng samples with the same growing time (with the same or similar number of stem scars) that had a thinner main root, a longer rhizome and more branch roots contained greater amounts of ginsenosides. For American ginseng, two tendencies were observed in the relationship between the diameter of the main root and contents of ginsenosides. One tendency was that samples with thinner main roots tended to contain higher levels of ginsenosides, which was observed in the samples sold under the commercial name pao-shen. Another tendency was that samples with thicker main roots contained higher contents of ginsenosides, which was observed in the samples sold under the commercial name pao-mian, as well as in samples of American ginseng cultivated in Jilin, China. Conclusion: An approach using ultra-HPLC-quadrupole/time-of-flight MS was successfully established to link morphology and active components for evaluating the quality of Asian and American ginsengs. Clear correlation between visible morphological features and quality of Asian and American ginsengs was found. People can see the difference; this means consumers and vendors can evaluate ginseng by themselves.

Expression of Hepatitis B Virus S Gene in Pichia pastoris andApplication of the Product for Detection of Anti-HBs Antibody

Hu Bo,Hong Guoqiang,Sun Yat-sen University of Medicine,Liang Minjian,Li Zhaoxia,Li Lin 한국생화학분자생물학회 2005 BMB Reports Vol.38 No.6