Enhancement of polyphenol content and antioxidant capacity of oat (Avena nuda L.) bran by cellulase treatment

Dongfang Chen,Junling Shi,Xinzhong Hu 한국응용생명화학회 2016 Applied Biological Chemistry (Appl Biol Chem) Vol.59 No.3

In this work, cellulase was used to treat with oat bran, and its effect on the total polyphenol content and phenolic profiles were investigated, with heating-only treatment as the control. Antioxidant capacity of the phenolic extracts from oat bran was assessed by scavenging of 2,2′-azinobis (3-ethylbenzothiazoline-6- sulphonic acid), 2, 2-diphenyl-1-picrylhydrazyl radical cation, the ferric reducing antioxidant power, and protein oxidative damage protection assays. As a result, cellulase treatment significantly increased the total phenolic content, total antioxidant capacity, and the ability on the protection of protein from oxidative damage of the oat bran compared with heating-only treatment. Furthermore, cellulase treatment significantly increased availability of most phenolic compounds, except of gallic acid, such as caffeic acid by 97 % (5.33 vs. 10.51 μg g−1), vanillin by 28 % (3.32 vs. 4.24 μg g−1), p-coumaric acid by 105 % (5.55 vs. 11.35 μg g−1), and ferulic acid by 914 % (12.33 vs. 124.03 μg g−1). However, heating-only treatment had no significant influence on the five detected phenolic compounds. Therefore, the study revealed that cellulase treatment would produce polyphenol-rich oat products with increased antioxidant activity.

Structure of hercynite prepared with existence of metal Fe

Junhong Chen,Dongfang Liu,Mingwei Yan, Yong Li,Jindong Su,Bin Li,Jialin Sun 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12

In this work, raw materials analytically pure Al2O3 and analytically pure Fe2O3 were mixed in FeO: Al2O3 molar ratio of 1 : 1and pressed into specimens. The specimens were embedded in analytically pure metal Fe powders and fired slowly to 1650 oCin air atmosphere, and then soaked at 1650 oC for 5 hrs. The fired specimens were investigated by XRD, SEM, and EDS. Theresults show that the specimen synthesized at high temperatures in melting Fe is composed of hercynite and wüstite (FenO(n ≤ 1)); FenO disperses in hercynite; hercynite crystals develop well and are mostly perfect octahedron with grain size around50μm. The hercynite has Fe/Al ratio smaller than 1/2, which is non-stoichimetric. With the existence of melting Fe, althoughthe raw materials are theoretically batched according to FeO·Al2O3, FenO is still excess, so the hercynite obtained is Al-rich.

Influence of compressor’s tilt angle on the performance of miniature refrigeration system

Xia Chen,Yuting Wu,Chongfang Ma,Chunxu Du,Rui Ma,Dongfang Wang 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.1

Vapor compression refrigeration is considered as ideal miniature cooling system for miniature electronic systems and portable cooling systems. Many applications of the miniature refrigeration system are working under the situations (such as aviation field, individual combat system and automobile air conditioning, etc.) that exist bump, tilt, and even flip, which will severely degrade the performance of the miniature refrigeration system. In order to study the influence of compressor’s tilt angle on refrigeration system, a test bench was built and the performance experiments were made. The results show that the compressor’s tilt angle has a great impact on the refrigeration system performance. When the compressor worked at the maximum tilt angle of 60°, COP-c and COP-h of the system change periodically. When the compressor works in full load, the maximum tilt angle for compressor is 20°. When the compressor tilt angle is 15°, there is an optimal amount of refrigerant charge, and corresponding COP-c and COP-h reach the maximum of 2.9 and 3.9, respectively.

Vehicle Platoon Tracking Control Based on Adaptive Neural Network Algorithm

Jie Huang,Jianfei Chen,Hongsheng Yang,Dongfang Li 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.10

To improve the tracking efficiency of the platoon during driving and ensure the spacing safety between vehicles, a platoon tracking control strategy based on the adaptive neural network algorithm is developed. In this method, the nonlinear term in the vehicle model is estimated by the adaptive neural network, and the estimated value is used to compensate for the control input and enhance the tracking performance of the vehicle platoon. In addition, the estimation update law of target trajectory and adjacent vehicle acceleration is designed through the adaptive method, which relaxes the trajectory generation requirements of virtual vehicles, improves the tracking performance of vehicle platoon, reduces the measurement and communication burden in the platoon, and ensures the security and stability of vehicle platoon system. After constructing the vehicle and desired path model, the control objective is formulated, and the adaptive neural network algorithm controller is designed. Meanwhile, the stability of the controller is verified by the Lyapunov method. The feasibility of the proposed method is proved by simulation and experiment. Rigorous theoretical derivation and experiments confirm that the proposed strategy has obvious advantages over other existing strategies.

Adsorption behavior of Congo red from aqueous solution on La2O3-doped TiO2 nanotubes

Hongxu Guo,Jianhua Chen,Wen Weng,Zishan Zheng,Dongfang Wang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

Composite adsorbent, TiO2 nanotubes doped by La2O3, were prepared and characterized by IR, XRD, SEM, and XPS, their adsorption properties were investigated in the aqueous solution employing Congo red as the target pollutant. The adsorption experiments exhibited that adsorption equilibrium of Congo red over the adsorbent was rapidly achieved within 10 min, and the adsorption kinetics was in accord with the pseudo-second-order kinetics model. Moreover, intraparticle diffusion was not the determining step in the entire adsorption process, and the adsorption belonged to a chemical adsorption. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isothermal equations were utilized to fit the equilibrium adsorption data, in which the Temkin equation was verified to fit the adsorption behaviors most satisfactorily with the correlation coefficient of 0.998. The adsorption mechanism was also studied.

Gastric Plexiform Fibromyxoma with Two Different Growth Patterns on Histological Images: a Case Report

Li, Zhenyu,Jiang, Qingming,Guo, Dongfang,Peng, Yangling,Zhang, Jing,Chen, Xinyu The Korean Gastric Cancer Association 2021 Journal of gastric cancer Vol.21 No.2

Plexiform fibromyxoma (PF) of the stomach is a very rare mesenchymal tumor of the gastrointestinal tract. We report the first case of PF with 2 different growth patterns pathologically confirmed after surgical resection. The tumor was characterized microscopically as infiltrative; it demonstrated diffuse growth into the smooth muscle bundles of the muscularis propria and was also multinodular and plexiform within the myxoid stroma. Immunohistochemical analysis revealed that the tumor cells were positive or weakly positive for smooth muscle actin, vimentin, and H-caldesmon and negative for desmin, CD117, CD34, CK-20, Pan-CK, Dog1, S100, ER, PR, and CD10. No mutations of C-kit and platelet-derived growth factor receptor alpha were detected. No genetic disruption of glioma-associated oncogene homolog 1 was detected by fluorescence in situ hybridization. The final diagnosis of PF was mainly based on the morphological and immunohistochemical findings.

Effects of Supercritical CO2 Treatment on Color, Lipid Oxidation, Heme Iron, Non-Heme Iron and Metmyoglobin Contents in Ground Pork

Shirong Huang,Min Tang,Fenfen Chen,Shengnan Zhao,Dongfang Chen 한국축산식품학회 2024 한국축산식품학회지 Vol.44 No.2

The color, lipid oxidation, heme iron (HI) and non-heme iron (NHI) contents, metmyoglobin content and Soret band of myoglobin of ground pork subjected to supercritical CO2 treatment under different conditions, or to heat treatment (40℃, 2 h) and subsequent storage at 4℃ were evaluated during 9-day period. Supercritical CO2 treatment significantly increased CIE L* and CIE b* values of ground pork during subsequent storage, while the HI content was slightly affected. In general, CIE a* value and metmyoglobin content were decreased. Supercritical CO2 treatment for 2 h could increase the thiobarbituric acid-reactive substances (TBARS) value, while treatment for 1 h or less had no effect. The NHI content could be increased only after treatment at above 40℃ or 17.2 MPa for 2 h. The Soret band of myoglobin was shifted to longer wavelength. Increasing treatment temperature from 35℃ to 45℃ could increase CIE L*, CIE a*, CIE b* and TBARS values, HI and NHI contents of the ground pork, while decreasing metmyoglobin content. As the treatment pressure increased from 13.8 MPa to 20.7 MPa, CIE b* and TBARS values were decreased, while the NHI and metmyoglobin contents were increased. However, the other parameters were unchanged. Extending exposure time from 0.5 h to 2 h could increase CIE L*, CIE b* and TBARS values, HI contents, while decreasing CIE a* value and metmyoglobin content. Correlation analysis showed that the TBARS value was significantly and negatively correlated with the HI content or metmyoglobin content in samples treated at 40℃ or above for 2 h.

Synthesis, characterization, and antioxidant activity in vitro of selenium‑Euryale ferox Salisb. polysaccharide

Dong Fang,Zheng Hu-Zhe,Jeong Woo-Sik,Chung Shin-Kyo,Qu Zhong-Yuan,Zou Xiang,Liu Chen,Xiang Qiong,Feng Feng 한국응용생명화학회 2021 Applied Biological Chemistry (Appl Biol Chem) Vol.64 No.S

In order to obtain and explore selenide composed of selenium and polysaccharide, three parameters were selected to optimize the synthesis process of selenium-Euryale ferox Salisb. polysaccharide (Se-ESPS) by Box-Behnken design. Furthermore, ESPS-B1 separated from ESPS was selenitized to Se-ESPS-B1 by the optimal synthesis process, then the characterization, and antioxidant activity in vitro of Se-ESPS-B1 were explored. The result manifested that the Se content of Se-ESPS was (2.915 ± 0.03) mg/g according to the optimal synthesis process of Se-ESPS (reaction time at 5 h, reaction temperature at 81 ℃, weight ratio of Na2SeO3 to ESPS at 0.9 g/g). A series of detection results indicated that the characterizations of Se-ESPS-B1 were apparently distinguished from that of ESPS-B1. Moreover, the antioxidant experiments in vitro demonstrated that Se-ESPS-B1 could exert antioxidant activity by scavenging DPPH, ABTS,·OH, and increasing reduction ability. In conclusion, the synthesis process is an effective approach to harvest seleniumpolysaccharide, and Se-ESPS-B1 may be utilized as a potential antioxidant or selenium nutritional supplement.