Structural and functional properties of Maillard-reacted casein phosphopeptides with different carbohydrates

Meng Yuan,Yu Cao,Haoyang Zheng,Kunlin Chen,Yuping Lu,Jing Wang,Liqin Zhu,Ming Chen,Zhipeng Cai,Yonggen Shen 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.7

This study used glucose, fructose, maltose and dextran to explore the effects of different carbohydrates on the Maillard reaction of casein phosphopeptides (CPP). The color parameter results showed that heating time from 1 to 5 h led to brown color, which was consistent with the observed increased in browning intensity. Fourier transform infrared spectroscopy results verified that four carbohydrates reacted with CPP to produce Maillard conjugates. Fluorescence spectroscopy showed that the Maillard reaction changed the tertiary structure of CPP by decreasing the intrinsic fluorescence intensity and surface hydrophobicity compared with the CPP-carbohydrate mixture. At the same time, the Maillard reaction effectively improved the emulsifying properties, reducing power and DPPH radical scavenging activity of CPP. Furthermore, this study also found that glucose and fructose improved CPP more than maltose and dextran. Therefore, monosaccharides have good potential in modifying CPP via the Maillard reaction.

Osmotic stress‐induced phosphorylation by NLK at Ser128 activates YAP

Hong, Audrey W,Meng, Zhipeng,Yuan, Hai‐,Xin,Plouffe, Steven W,Moon, Sungho,Kim, Wantae,Jho, Eek‐,hoon,Guan, Kun‐,Liang EMBO 2017 EMBO reports Vol.18 No.1

<P>YAP is the major downstream effector of the Hippo pathway, which controls cell growth, tissue homeostasis, and organ size. Aberrant YAP activation, resulting from dysregulation of the Hippo pathway, is frequently observed in human cancers. YAP is a transcription co-activator, and the key mechanism of YAP regulation is its nuclear and cytoplasmic translocation. The Hippo pathway component, LATS, inhibits YAP by phosphorylating YAP at Ser127, leading to 14-3-3 binding and cytoplasmic retention of YAP. Here, we report that osmotic stress stimulates transient YAP nuclear localization and increases YAP activity even when YAP Ser127 is phosphorylated. Osmotic stress acts via the NLK kinase to induce YAP Ser128 phosphorylation. Phosphorylation of YAP at Ser128 interferes with its ability to bind to 14-3-3, resulting in YAP nuclear accumulation and induction of downstream target gene expression. This osmotic stress-induced YAP activation enhances cellular stress adaptation. Our findings reveal a critical role for NLK-mediated Ser128 phosphorylation in YAP regulation and a crosstalk between osmotic stress and the Hippo pathway.</P>

Optimization of impulse water turbine based on GA-BP neural network arithmetic

Lingdi Tang,Shouqi Yuan,Yue Tang,Zhipeng Qiu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

To develop an optimum design method for impulse water turbines with low specific speed, a representative impulse water turbine with low specific speed used in agricultural irrigation machinery was optimized with a combination of an orthogonal experimental design, a genetic algorithm, and a BP neural network in this study. Numerical calculation was applied to analyze interflow characteristics for optimized and original water turbines. Results showed that the internal flow characteristics of the optimized water turbine presented remarkable improvement compared with the original water turbine. Pressure distribution increased, the vortex strip in the draft tube was reduced remarkably, and impeller torque increased by 26 %. In addition, the optimized impeller was manufactured by 3D printing, and performance comparison was conducted between experiments of the optimized and original water turbines. The efficiency of the optimized water turbine reached 42.5 %, which exceeded the original water turbine’s of 8.5 %. With increasing rotating speed, maximum efficiency running point moved to a high flow rate, and highly efficient areas expanded. Internal characteristic analysis and a full-scale experiment for both water turbines showed that the performance of the optimized water turbine exhibited substantial improvement. The analysis and experiment also verified the theoretical correctness and feasibility of the proposed optimum design method.

Transmission Line Modeling and Algorithm Analysis Considering Parameter Asymmetry and Transient High-frequency Components

Mo Shixun,Lv Zhipeng,Han Kunlun,Yuan Rongji,Yang Hao,Jiang Kunping,Liang Zhenshen 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.2

When the power system is disturbed or the operation mode is changed, the electromagnetic transient process will occur, which will lead to the high frequency transient component and aff ect the protection and control of the power system. Therefore, attention should be paid to the analysis of high-frequency transient components when modeling and analyzing the system model. In view of the fact that the symmetrical-component theory is not suitable for asymmetric transmission lines and the phasor method is not suitable for transient analysis and calculation, this paper uses the phase coordinate approach and Laplace transform to derive the node voltage equation of three-phase π type transmission lines in frequency domain, which can be used to calculate the transient response of transmission lines caused by the change of operation mode or disturbance. And vectorized NILT is used to calculate the time domain solution, which greatly improves the calculation speed. The calculated results are basically consistent with those of ATP-EMTP, and can fully refl ect the transient characteristics. This method lays a foundation for analyzing the infl uence of high frequency transient components on power system and fault analysis considering transient process.

Characterization and performance test of phenolphthalein poly(aryl ether ketone) fractionated by incremental poor solvent fractionation

Zengxu Qian,Jingwei Jiang,Yunlong Sun,Qiliang Yuan,Zhichao Wang,Zhipeng Wang,Guangyuan Zhou 한국고분자학회 2023 Macromolecular Research Vol.31 No.8

Though phenolphthalein poly(aryl ether ketone) (PEK-C) has gained attention as a special engineering plastic materials by virtue of its good thermal stability and favorable mechanical properties, its applications are limited due to its wide PDI during polymerization, which result in poor mechanical properties of PEK-C. In order to investigate the effect of molecular weight and polydispersity index (PDI) on PEK-C, an incremental poor solvent fractionation method was used to fractionate PEK-C. The process produced a series of grades with decreasing molecular weight and PDI. The LCP (linear cloud point) equation was combined with the grading method to find the optimal PEK-C/DMAc/ Non-solvent additives (NSA) system, which can be used to improve the grading efficiency. The obtained results showed that the incremental poor solvent fractionation method with the PEK-C/DMAc/EA system made the molecular weight distributed in the range of 25 ~ 113 kDa, PDI mostly distributed in the range of 1.1 ~ 1.4, and the narrowest PDI to reach 1.13, which could not be obtained through the condensation reaction. Meanwhile, we can also achieve expanded production. By fractionation, the elastic modulus of PEK-C film could be increased by up to 22.6%, elongation at break by up to 38.3%, the fracture strength by up to 38.2%, and impact strength of the sheest by up to 41.2%, while the polymer still maintained good thermal and UV shielding properties. This unique Polymer/Solution/NSA system can yield an effective design strategy for controlling its molecular weight and PDI and improving its mechanical performance.

Design of carbonized unidirectional polyimide aerogel for CO2 capture: Effect of pore morphology/topology on CO2 capture

Xinfu Zhao,Yihao Nie,Xibin Yi,Shimo Yu,Jing Zhang,Xiaochan Liu,Zhipeng Yuan,Sijia Liu,Jian Zhang,Guoliang Dou,Mengdi Wang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Design of efficient CO2 adsorbent is an effective way to capture CO2. Bamboo-derived activated carbon isa promising CO2 adsorbent. Inspired by this, carbonized unidirectional polyimide (CUPI) aerogels werenewly designed by the ice templating method using directional freezing technology. The pore propertyof CUPI aerogel can be tuned by changing the solidification velocity, and a series of CUPI aerogels weredesigned to explore the CO2 capture performance in view of pore morphology/topology. As a result,the obtained CUPI-8 exhibits higher CO2 adsorption capacity compared to carbonized polyimide aerogelsdue to the synergistic effect of micropores and lamellar pores. Specially, the CO2 adsorption capacity overCUPI-8 can be up to 5.75 mmol/g at 20 bar and 298 K. Furthermore, the adsorption isotherm of CUPI-8still shows an upward trend even nearly 20 bar. The isosteric adsorption heat (Qst) value of CUPI-8 isnearly in the ideal scope of 30–50 kJ mol1. The efficient CO2 adsorption performance and good chemicalstability of CUPI aerogel makes it a promising absorbent for practical application. This work provides anew opportunity for researching the effect of pore morphology/topology and the synergistic effect ofhierarchical pores on CO2 capture.