Preparation and Drug-releasing Properties of Chitosan-based Thermosensitive Composite Hydrogel

Li, Heping,Yu, Tao,Li, Shan,Qin, Long,Ning, Jingheng Korean Chemical Society 2012 대한화학회지 Vol.56 No.4

The novel chitosan-based thermosensitive hydrogels were prepared as control-releasing drug carriers. N-carboxyethyl chitosan (ACS) was synthesized by microwave heating for 1 h through Michael addition of CS to acrylic acid in a grafting yield of 52.97%, which was proved to be a faster and more efficient way than ordinary methods. 5-Fu was modified with formaldehyde to synthesize N,N'-Bis(hydroxymethyl)-5-fluorouracil (5-Fu-OH). Then an esterification was performed using ACS and 5-Fu-OH to give 5-Fu-ACS. The new thermosensitive hydrogels were prepared by adding sodium glycerophosphate to the solution of compounds under a certain constant temperature. Simultaneously, the hydrogels' swelling rate, in vitro drug release rate and thermosensitive were studied, and found that the 5-Fu-ACS composite hydrogel had more excellent releasing effect, higher drug loading and better thermosensitive.

Synthesis of Polyamine Grafted Chitosan Copolymer and Evaluation of Its Corrosion Inhibition Performance

Li, Heping,Li, Hui,Liu, Yi,Huang, Xiaohua Korean Chemical Society 2015 대한화학회지 Vol.59 No.2

Two new chitosan derivatives, polyamine grafted chitosan copolymers have been synthesized for corrosion protection of carbon steel in acidic medium. First, methyl acrylate graft chitosan copolymer (CS-MAA) was prepared by the reaction of chitosan (CS) and methyl acrylate (MAA) via the Michael addition reaction. Then, CS-MAA was reacted with ethylene diamine (EN) and triethylene tetramine (TN) respectively to synthesize ethylene diamine grafted chitosan copolymer (CS-MAA-EN) and triethylene tetramine grafted chitosan copolymer (CS-MAA-TN), and the structures were characterized by Fourier-transform infrared spectroscopy (FT-IR). At last, the corrosion inhibition activities on Q235 carbon steel were investigated by using gravimetric measurements, metallographic microscope, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The compounds CS-MAA-EN and CS-MAA-TN show an appreciable corrosion inhibition property against corrosion of Q235 carbon steel in 5% HCl solution at $25^{\circ}C$. It has been observed that CS-MAA-EN shows greater corrosion inhibition efficiency than CS-MAA-TN. The inhibition efficiency of CS-MAA-EN was close to 90% when the mass fraction concentration was 0.2%~0.3%; the inhibition efficiency of CS-MAA-TN was close to 85% when the mass fraction concentration was 0.02%. The present work provided very promising results in the preparation of green corrosion inhibitors.

Integrated Method for Text Detection in Natural Scene Images

( Yang Zheng ),( Jie Liu ),( Heping Liu ),( Qing Li ),( Gen Li ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.11

In this paper, we present a novel image operator to extract textual information in natural scene images. First, a powerful refiner called the Stroke Color Extension, which extends the widely used Stroke Width Transform by incorporating color information of strokes, is proposed to achieve significantly enhanced performance on intra-character connection and non-character removal. Second, a character classifier is trained by using gradient features. The classifier not only eliminates non-character components but also remains a large number of characters. Third, an effective extractor called the Character Color Transform combines color information of characters and geometry features. It is used to extract potential characters which are not correctly extracted in previous steps. Fourth, a Convolutional Neural Network model is used to verify text candidates, improving the performance of text detection. The proposed technique is tested on two public datasets, i.e., ICDAR2011 dataset and ICDAR2013 dataset. The experimental results show that our approach achieves state-of-the-art performance.

Development of polymorphic EST-SSR markers by sequence alignment in Frankliniella occidentalis (Pergande)

Jiani Liu,Zheng-Yue Li,Xiaoyan Chen,Heping Huang,Furong Gui 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

The western flower thrips, Frankliniella occidentalis, is the most economically important agronomic pest withinThysanoptera because it is both a direct pest of horticulture crops and an efficient vector of plant viruses. Sixty-seven polymorphic SSR loci were identified in the contigs (containing redundant ESTs) generated byassembling 13,839 F. occidentalis ESTs from the public sequence database. Nineteen SSR markers exhibited polymorphismamong 860 samples from43 F. occidentalis populations,with alleles per SSR marker ranging fromtwoto eight, the effective number of alleles (Ne) range from 0.73 to 2.64; the observed (Ho) and expected (He) heterozygositiesranged from 0.09 to 0.77 and 0.12 to 0.96, respectively. The PIC values were from 0.24 to 0.73. AMOVA revealed most genetic variation resided within, rather than between, greenhouse and field isolates. The Mantel test showed no significant differences between genetic and geographical distances. We demonstratedthe value of mining the redundant sequences in public sequence databases for the development of polymorphicSSR markers, which can be used for better understanding population variation and spreading of the invasive pestF. occidentalis.

State trend prediction of hydropower units under different working conditions based on parameter adaptive support vector regression machine modeling

Guo Zhao,Shulin Li,Wanqing Zuo,Haoran Song,Heping Zhu,Wenjie Hu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.9

To address the problem where the different operating conditions of hydropower units have a large influence on the parameters of the trend prediction model of the operating condition indicators, a support vector regression machine prediction model based on parameter adaptation is proposed in this paper. First, the Aquila optimizer (AO) is improved, and a sine chaotic map is introduced to influence the population initialization process. An improved adaptive weight factor is used to balance the local search and global search capabilities. Second, according to the power and the head, the operating conditions of the unit are refined into several typical sets of operating conditions. On this basis, an SVR model is established using the improved AO search algorithm proposed in this paper, and the prediction parameters under each of the operating condition are optimized to establish the data of the operating conditions and optimal parameters. Then a neural network is used to fit the working condition and the optimal prediction parameters. In addition, the nonlinear function mapping of the complex relationship between the two is constructed. Finally, the constructed mapping relationship is added to the traditional SVR, and an adaptive SVR prediction model suitable for changes in the working conditions of hydropower units is realized. Simulation results show that when compared to the traditional SVR prediction model, the adaptive SVR prediction model designed in this paper can automatically adjust the prediction parameters according to changes in the working conditions and achieve the goal of maintaining optimal prediction performance under different working conditions. In addition, it has the ability to accurately predict the development trend of the unit operating state index within a certain time scale.

Yeast Surface Display of Capsid Protein VP7 of Grass Carp Reovirus: Fundamental Investigation for the Development of Vaccine Against Hemorrhagic Disease

( Shaoxiang Luo ),( Liming Yan ),( Xiaohua Zhang ),( Li Yuan ),( Qin Fang ),( Yong An Zhang ),( Heping Dai ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.12

VP7, an outer capsid protein of grass carp reovirus (GCRV), was expressed and displayed on the surface of Saccharomyces cerevisiae for developing an efficient vaccine against hemorrhagic disease of grass carp. The result of flow cytometry analysis indicated that protein VP7 could be displayed on the surface of yeast cells after inducing with galactose. The expression of VP7 was confirmed by western blot analysis and further visualized with confocal microscopy. The specific antibodies against VP7 generated from mice were detectable from all immune groups except the control group, which was immunized with untransformed yeast cells. The displaying VP7 on glycosylation-deficient strain EBYΔMnn9 was detected to induce a relatively low level of specific antibody amongst the three strains. However, the antiserum of EBYΔM9-VP7 showed relative high capacity to neutralize GCRV. Further neutralization testing assays indicated that the neutralizing ability of antiserum of the EBYΔM9-VP7 group appeared concentration dependent, and could be up to 66.7% when the antiserum was diluted to 1:50. This result indicates that appropriate gene modification of glycosylation in a yeast strain has essential effect on the immunogenicity of a yeast-based vaccine.

Molecular cloning and expression analysis of annexin A2 gene in sika deer antler tip

Xia, Yanling,Qu, Haomiao,Lu, Binshan,Zhang, Qiang,Li, Heping Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.4

Objective: Molecular cloning and bioinformatics analysis of annexin A2 (ANXA2) gene in sika deer antler tip were conducted. The role of ANXA2 gene in the growth and development of the antler were analyzed initially. Methods: The reverse transcriptase polymerase chain reaction (RT-PCR) was used to clone the cDNA sequence of the ANXA2 gene from antler tip of sika deer (Cervus Nippon hortulorum) and the bioinformatics methods were applied to analyze the amino acid sequence of Anxa2 protein. The mRNA expression levels of the ANXA2 gene in different growth stages were examined by real time reverse transcriptase polymerase chain reaction (real time RT-PCR). Results: The nucleotide sequence analysis revealed an open reading frame of 1,020 bp encoding 339 amino acids long protein of calculated molecular weight 38.6 kDa and isoelectric point 6.09. Homologous sequence alignment and phylogenetic analysis indicated that the Anxa2 mature protein of sika deer had the closest genetic distance with Cervus elaphus and Bos mutus. Real time RT-PCR results showed that the gene had differential expression levels in different growth stages, and the expression level of the ANXA2 gene was the highest at metaphase (rapid growing period). Conclusion: ANXA2 gene may promote the cell proliferation, and the finding suggested Anxa2 as an important candidate for regulating the growth and development of deer antler.