Characterization of proteolysis in muscle tissues of sea cucumber Stichopus japonicus

Chen-Chen Zhao,Yang Yang,Hai-tao Wu,Zhi-Mo Zhu,Yue Tang,Cui-Ping Yu,Na Sun,Qiang Lv,Jia-Run Han,Ao-Ting Li,Jia-Nan Yan,Yue Cha 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.6

The proteolysis in muscle tissues of sea cucumber Stichopus japonicus (sjMTs) was characterized. The proteins from sjMTs were primarily myosin heavy chains (MHCs), paramyosin (Pm), and actin (Ac) having a molecular mass of approximately 200, 98, and 42 kDa, respectively. Based on SDS-PAGE analysis and quantification of trichloroacetic acid (TCA)-soluble peptides released, degradation of muscle proteins from sjMTs was favorable at pH 5 and 50°C. Proteolysis of MHCs was mostly inhibited by cysteine protease inhibitors, including trans-epoxysuccinyl-L-leucyl-amido (4- guanidino) butane (E-64) and antipain (AP). E-64 and AP completely inhibited the degradation of Pm and Ac, while iodoacetic acid showed a partially inhibitory effect. These results indicated that the proteolysis of sjMTs was mainly attributed to cysteine proteases. Avoidance of setting the tissues at 40–50oC and slightly acidic condition and inhibition of cysteine proteases are helpful for decreasing sea cucumber autolysis.

Puerarin pretreatment attenuates cardiomyocyte apoptosis induced by coronary microembolization in rats by activating the PI3K/Akt/GSK-3β signaling pathway

Chen, Zhi-Qing,Zhou, You,Huang, Jun-Wen,Chen, Feng,Zheng, Jing,Li, Hao-Liang,Li, Tao,Li, Lang The Korean Society of Pharmacology 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.2

Coronary microembolization (CME) is associated with cardiomyocyte apoptosis and cardiac dysfunction. Puerarin confers protection against multiple cardiovascular diseases, but its effects and specific mechanisms on CME are not fully known. Hence, our study investigated whether puerarin pretreatment could alleviate cardiomyocyte apoptosis and improve cardiac function following CME. The molecular mechanism associated was also explored. A total of 48 Sprague-Dawley rats were randomly divided into CME, CME + Puerarin (CME + Pue), sham, and sham + Puerarin (sham + Pue) groups (with 12 rats per group). A CME model was established in CME and CME + Pue groups by injecting 42 ㎛ microspheres into the left ventricle of rats. Rats in the CME + Pue and sham + Pue groups were intraperitoneally injected with puerarin at 120 mg/kg daily for 7 days before operation. Cardiac function, myocardial histopathology, and cardiomyocyte apoptosis index were determined via cardiac ultrasound, hematoxylin-eosin (H&E) and hematoxylin-basic fuchsin-picric acid (HBFP) stainings, and TdT-mediated dUTP nick-end labeling (TUNEL) staining, respectively. Western blotting was used to measure protein expression related to the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway. We found that, puerarin significantly ameliorated cardiac dysfunction after CME, attenuated myocardial infarct size, and reduced myocardial apoptotic index. Besides, puerarin inhibited cardiomyocyte apoptosis, as revealed by decreased Bax and cleaved caspase-3, and up-regulated Bcl-2 and PI3K/Akt/GSK-3β pathway related proteins. Collectively, puerarin can inhibit cardiomyocyte apoptosis and thus attenuate myocardial injury caused by CME. Mechanistically, these effects may be achieved through activation of the PI3K/Akt/GSK-3β pathway.

Meta-analysis of Associations between the MDM2-T309G Polymorphism and Prostate Cancer Risk

Chen, Tao,Yi, Shang-Hui,Liu, Xiao-Yu,Liu, Zhi-Gang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.9

The mouse double minute 2 (MDM2) gene plays a key role in the p53 pathway, and the SNP 309T/G single-nucleotide polymorphism in the promoter region of MDM2 has been shown to be associated with increased risk of cancer. However, no consistent results were found concerning the relationships between the polymorphism and prostate cancer risk. This meta-analysis, covering 4 independent case-control studies, was conducted to better understand the association between MDM2-SNP T309G and prostate cancer risk focusing on overall and subgroup aspects. The analysis revealed, no matter what kind of genetic model was used, no significant association between MDM2-SNP T309G and prostate cancer risk in overall analysis (GT/TT: OR = 0.84, 95%CI = 0.60-1.19; GG/TT: OR = 0.69, 95%CI = 0.43-1.11; dominant model: OR = 0.81, 95%CI= 0.58-1.13; recessive model: OR = 1.23, 95%CI = 0.95-1.59). In subgroup analysis, the polymorphism seemed more likely to be a protective factor in Europeans (GG/TT: OR = 0.52, 95%CI = 0.31-0.87; recessive model: OR = 0.58, 95%CI = 0.36-0.95) than in Asian populations, and a protective effect of the polymorphism was also seen in hospital-based studies in all models (GT/TT: OR = 0.74, 95%CI = 0.57-0.97; GG/TT: OR = 0.55, 95%CI = 0.38-0.79; dominant model: OR = 0.69, 95%CI = 0.54-0.89; recessive model: OR = 0.70, 95%CI = 0.51-0.97). However, more primary studies with a larger number of samples are required to confirm our findings.

A damage localization method based on the singular value decomposition (SVD) for plates

Zhi-Bo Yang,Jin-Tao Yu,Shao-Hua Tian,Xue-Feng Chen,Guan-Ji Xu 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.5

Boundary effect and the noise robustness are the two crucial aspects which affect the effectiveness of the damage localization based on the mode shape measurements. To overcome the boundary effect problem and enhance the noise robustness in damage detection, a simple damage localization method is proposed based on the Singular Value Decomposition (SVD) for the mode shape of composite plates. In the proposed method, the boundary effect problem is addressed by the decomposition and reconstruction of mode shape, and the noise robustness in enhanced by the noise filtering during the decomposition and reconstruction process. Numerical validations are performed on plate-like structures for various damage and boundary scenarios. Validations show that the proposed method is accurate and effective in the damage detection for the two-dimensional structures.

Random vibration analysis of train-slab track-bridge coupling system under earthquakes

Zhi-ping Zeng,Xian-feng He,Yan-gang Zhao,Zhi-wu Yu,Ling-kun Chen,Wen-tao Xu,Ping Lou 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.5

This study aimed to investigate the random vibration characteristic of train-slab track-bridge interaction system subjected to both track irregularities and earthquakes by use of pseudo-excitation method (PEM). Each vehicle subsystem was modeled by multibody dynamics. A three-dimensional rail-slabgirder-pier finite element model was created to simulate slab track and bridge subsystem. The equations of motion for the entire system were established based on the constraint condition of no jump between wheel and rail. The random load vectors of equations of motion were formulated by transforming track irregularities and seismic accelerations into a series of deterministic pseudo-excitations according to their respective power spectral density (PSD) functions by means of PEM. The time-dependent PSDs of random vibration responses of the system were obtained by step-by-step integration method, and the corresponding extreme values were estimated based on the first-passage failure criterion. As a case study, an ICE3 high-speed train passing a fifteen-span simply supported girder bridge simultaneously excited by track irregularities and earthquakes is presented. The evaluated extreme values and the PSD characteristic of the random vibration responses of bridge and train are analyzed, and the influences of train speed and track irregularities (without earthquakes) on the random vibration characteristic of bridge and train are discussed.

A Study on the Strain Stability of Si/SiGe Layer Structure in a Heterojunction Bipolar Transistor during Thermal Processing

Zhi Hong Liu,Chang Chun Chen,Wen Tao Huang,Wei Zhi Dou,Yi Lin Shan,Wei Zhang,Jun Zhu,Pei Hsin Tsien 대한금속학회 2004 METALS AND MATERIALS International Vol.10 No.3

A damage localization method based on the singular value decomposition (SVD) for plates

Yang, Zhi-Bo,Yu, Jin-Tao,Tian, Shao-Hua,Chen, Xue-Feng,Xu, Guan-Ji Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.22 No.5

Boundary effect and the noise robustness are the two crucial aspects which affect the effectiveness of the damage localization based on the mode shape measurements. To overcome the boundary effect problem and enhance the noise robustness in damage detection, a simple damage localization method is proposed based on the Singular Value Decomposition (SVD) for the mode shape of composite plates. In the proposed method, the boundary effect problem is addressed by the decomposition and reconstruction of mode shape, and the noise robustness in enhanced by the noise filtering during the decomposition and reconstruction process. Numerical validations are performed on plate-like structures for various damage and boundary scenarios. Validations show that the proposed method is accurate and effective in the damage detection for the two-dimensional structures.

Tax is Involved in Up-regulation of HMGB1 Expression Levels by Interaction with C/EBP

Zhang, Chen-Guang,Wang, Hui,Niu, Zhi-Guo,Zhang, Jing-Jing,Yin, Ming-Mei,Gao, Zhi-Tao,Hu, Li-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

The high mobility group box 1 (HMGB1) protein is a multifunctional cytokine-like molecule that plays an important role in the pathogenesis of tumors. In this study, real-time polymerase chain reactions and Western blot assays indicated that HMGB1 transcriptional activity and protein level are increased in $Tax^+$-T cells (TaxP). To clarify the mechanisms, a series of HMGB1 deletion reporter plasmids (pHLuc1 to pHLuc6) were transfected into $Tax^-$-T cells (TaxN, Jurkat) and $Tax^+$-T cells (TaxP). We found that promoter activity in $Tax^+$-T cells to be higher than that in $Tax^-$-T cells, indicating a significant increase in pHLuc6. Bay11-7082 (NF-${\kappa}B$ inhibitor) treatment did not block the enhancing effect. Chromatin immunoprecipitation assays revealed that Tax was retained on a HMGB1 promoter fragment encompassing -1163 to -975. Bioinformatics analysis showed six characteristic cis-elements for CdxA, AP-1, AML-1a, USF, v-Myb, and C/EBP in the fragment in question. Mutation of cis-elements for C/EBP reduced significant HMGB1 promoter activity induced by Tax. These findings indicate that Tax enhances the expression of HMGB1 gene at the transcriptional level, possibly by interacting with C/EBP.

Robust Finite-time Attitude Tracking Control of Rigid Spacecraft Under Actuator Saturation

Hai-Tao Chen,Shen-Min Song,Zhi-Bin Zhu 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.1

This paper investigates the robust finite-time attitude tracking control problem for rigid spacecraft considering the modeling uncertainty, external disturbance and actuator saturation. An auxiliary system is proposed to directly compensate for the saturated control input. First, the basic controller is formulated based on the fast nonsingular terminal sliding mode surface (FNTSMS), the fast-TSM-type reaching law and the auxiliary system in the presence of upper bounded external disturbance. Then, when facing system uncertainty which consists of both modeling uncertainty and external disturbance and has upper bounded first derivative, the extended state observer (ESO) is associated with the first controller to improve the robustness of control system. Furthermore, to handle more general system uncertainty which is upper bounded by a polynomial function of the closed-loop system states, a continuous adaptive controller is designed to compensate for the total system uncertainty on line. The proposed controllers are able to deal with system uncertainty, input singularity and actuator saturation, while simultaneously providing fast finite-time convergence speed for the control system. And the problems of complex parameters selection process and repeated differentiations of nonlinear functions can be avoided. Rigorous stability analyses are given via the Lyapunov stability theory and digital simulations are conducted to illustrate the effectiveness of the proposed controllers.

High‑speed growth of high‑quality polycrystalline diamond films by MPCVD

Kai Chen,Tao Tao,Wenxiao Hu,Yucong Ye,Kaiwen Zheng,Jiandong Ye,Ting Zhi,Xiwei Wang,Bin Liu,Rong Zhang 한국탄소학회 2023 Carbon Letters Vol.33 No.7

High-quality diamond films have attracted extensive attentions due to their excellent optical and electrical properties. However, several issues, such as random orientation, stress accumulation, and slow growth rate, severely limit its applications. In this paper, high-quality polycrystalline diamond films with highly ordered (100) orientation were prepared by microwave plasma chemical vapor deposition. The effects of growth parameters on the microstructure, quality and residual stress of diamond films were investigated. Experimental results indicate that relatively high temperature at low methane concentration will promote the formation of (100) oriented grains with a low compressive stress. Optimized growth parameters, a methane concentration of 2% along with a pressure of 250 Torr and temperature at 1050 ℃, were used to acquire high growth rate of 7.9 μm/h and narrow full width at half maximum of Raman peak of 5.5 cm? 1 revealing a high crystal quality. It demonstrates a promising method for rapid growth of high-quality polycrystalline diamond films with (100) orientation, which is vital for improving the diamond related applications at low cost.