Enzymatic characteristics of polyphenoloxidase from shrimp (Penaeus vannamei) and its inhibition by a novel hydroxypyridinone derivative

Le-Le Shao,Jia-Min Zhou,Qing Zhu,Xiao-Ling Wang,Robert C. Hider,Tao Zhou 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.4

Melanosis developed in shrimp (Penaeus vannamei)is mainly initiated by polyphenoloxidase (PPO),thus understanding of the characteristics of PPO in shrimpis important for controlling the melanosis of shrimp. Theshrimp cephalothorax turns black most rapidly amongst allthe tissues during the chilled storage. Crude PPO extractedfrom this cephalothorax has an optimal pH of 6.0 and anoptimal temperature of 50 C. PPO is relatively stable underneutral and weak alkaline conditions (pH 5.5–9.0) andthe temperature range of 25–35 C. The kinetic parametersKm and Vmax were recorded as 3.02 mM and 54.3 U/mg ofprotein, respectively, using L-Dopa as a substrate. Themolecular weight of PPO was estimated as 200–220 kDaby an activity staining test. A hydroxypyridinone derivative,5-hydroxy-1-octyl-4-oxo-1,4-dihydropyridine-2-carbaldehydeO-ethyl oxime, was demonstrated to efficientlyinhibit the PPO, indicating that this compound might findapplication as a shrimp preservative.

Command Filter-based Backstepping Control for the Speed and Tension System of the Reversible Cold Strip Rolling Mill Using Disturbance Observers

Le Liu,Nuan Shao,Suyan Ding,Yi-ming Fang 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.5

This paper investigates the decoupling and coordinated tracking control problem for the speed and tension system of the reversible cold strip rolling mill. Using a diagonal matrix decoupling network and neural network disturbance observers, we propose a command filter-based backstepping control strategy. First, the diagonal matrix decoupling network is constructed to weaken the coupling between the speed and tension of the rolling mill system, which reduces the complexity of the system model effectively. Second, controllers are designed by combining the backstepping with the command filter, which solves the “explosion of complexity” problem in backstepping procedure, and optimizes the system’s control structure. Next, neural network disturbance observers are developed to observe the uncertain items of the system, which improve the tracking control precision of the system effectively. Theoretical analysis shows that all signals in the closed-loop system are uniformly ultimately bounded. Finally, simulation research is carried out on the speed and tension system of a 1422 mm reversible cold strip rolling mill; results show that using the proposed control strategy increased the dynamic response speed of the system by approximately 1s, and the stability precision improved by approximately 2000 N.

Structural Evaluation of Torsional Rigidity of New FRP–Aluminum Space Truss Bridge with Rigid Transverse Braces

Le Zhu,Dongdong Zhang,Fei Shao,Qian Xu,Qilin Zhao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

A unique fiber-reinforced polymer (FRP)–aluminum spatial truss structure with upper I-type, transverse beam braces was developed for deployable bridging, yielding the operational advantages of bestraddled erection bridges. Experimental testing and numerical simulation were performed to evaluate the torsional rigidity of a fabricated cantilever, full-scale experimental structure. The predictions obtained based on a computational finite element model were strongly consistent with the experimental results. Moreover, a numerical decomposition and reconstruction procedure was employed to understand the load-bearing mechanism of the structure. The results demonstrated that the improved transverse braces possessed adequate capacity for providing sufficient rigidity and lateral stability to the complete twin-treadway structure under torsion. The torsional center of the improved structure was located at the axis of symmetry of the twin-treadway bridge deck. The representative torsional rigidity of the twin-treadway module was approximately 87.5 kN·m2/degree. Compared to the original construction, the improved structure exhibited only minor discrepancies regarding the torsional rigidity, and consistent characteristics in terms of the load-bearing mechanism. The torsional rigidity of the improved twin-treadway structure was primarily generated by the vertical bending rigidities of its two parallel single treadways through the rigid transverse braces. This significant finding specifically pertains to the unique twin-treadway hybrid bridge. The results presented in this work are expected to provide valuable insights, which could, in turn, lead to further the development of similar lightweight structural systems.

The effect of body mass index and its interaction with family history on hypertension: a case–control study

An-le Li,Qian Peng,Yue-qin Shao,Xiang Fang,Yi-ying Zhang 대한고혈압학회 2019 Clinical Hypertension Vol.25 No.2

Background: BMI is an indicator commonly used in the world to measure the weight and height of the body, it reflects the comprehensive outcome of acquired lifestyle; FH is a sign reflecting the main role of genetic factors. This study aimed to evaluate the effect of BMI and interaction with FH on hypertension risk in Shanghai adult population. Methods: According to l:l matched pairs design, 342 cases and 342 controls were selected and investigated in this study, this study was performed in Shanghai, China. Participants received face-to-face questionnaire survey, anthropometric tests and laboratory examinations. Relevant indicators that reflect obesity including BMI and waist to hip ratio (WHR) were calculated. Multivariate logistic regression analysis was applied to explore the association between factors and hypertension risk. Interactive effect was evaluated by synergy index (SI), relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and the percentage of the interaction between the pure factors (PAP). Results: Among 684 study participants aged 28–87 years old, the differences of mean age and height between case group and control group are no significant (p > 0.05), but the differences of mean of weight, WC, HC, BMI and WHR are significant (p < 0.001). The OR of FH on hypertension is 4.986 (95%CI: 2.832~ 8.877); the OR of BMI on hypertension is respectively: low weight is 1.528 (95%CI: 0.551~ 4.239), overweight is 3.333 (95%CI: 1.678~ 6.617) and obesity is 7.312 (95%CI: 3.556~ 15.035). The OR of interaction between FH and BMI to hypertension is 12.993 (95%CI: 7.426~22.734). SI is 1.90 (95% CI: 1.48~3.78), RERI is 5.67 (95% CI: 1.66~11.88), AP is 43.87% (95% CI: 12.84~91.88%), and PAP is 47.55% (95%CI: 13.91~99.58%). FH and BMI have positive interaction on hypertension. 43.87% of hypertension exposed to both FH and BMI was attributable to the interaction of them. Conclusions: FH and BMI are significant higher risks of hypertension; with the increase of BMI, the risk of hypertension will increase more. FH and BMI have positive interaction with hypertension, the interaction is greater than the sum of two independent actions.

Effect of Ultrasonic Power on Grain Refinement and Purification Processing of AZ80 Alloy by Ultrasonic Treatment

Zhiwen Shao,Qichi Le,Zhiqiang Zhang,Jianzhong Cui 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.2

Ultrasound with different powers was applied to treat AZ80 alloy melt to attain grain refinement or purifi-cation processing of the alloy. The influence of ultrasonic powers from 0 W to 1400 W on microstruc-tures of the AZ80 alloy with ultrasonic grain refinement treatment was investigated. The average grain size of the alloy could be decreased from 387 µm to 147 µm after the ultrasound with the optimal power 600 W was applied to treat the melt. The effect of ultrasonic powers from 0 W to 230 W on the inclusion distribution in the ingot that was treated by ultrasonic purification processing was also studied. The opti-mal ultrasonic power in the ultrasonic purification processing was 80 W. In order to gain insight into the mechanism by which ultrasonic power affected the microstructure of the alloy or inclusion distribution in the ingot, numerical simulations were carried out and the ultrasonic field propagation in the melt was characterized.

A Unequalven Clustering Routing Protocol in Wireless Sensor Networks

Deyu Zhang,Le Jiao,Yanjun Chen,Junping Shao 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.9

A hemoglobin-based oxygen-carrying biomimetic nanosystem for enhanced chemo-phototherapy and hypoxia alleviation of hepatocellular carcinoma

Jing-Qing Le,Fang Yang,Xun-Huan Song,Ke-Ke Feng,Ling-Wu Tong,Meng-Die Yin,Wen-Zhong Zhang,Ying-Qi Lin,Hui Wu,Jing-Wei Shao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

Tumor microenvironment is characterized by low pH, high reactive oxygen species and hypoxia, whichprovides a suitable environment for cancer growth. The hypoxia not only elevates tumor angiogenesisand metastasis, but also is responsible for the development of treatment resistance, which graduallybecomes a significant impediment for cancer therapy. Therefore, we developed a biomimetic nanosystemcontaining hemoglobin extracted from red blood cells, chemotherapy drug sorafenib, sensitizer ursolicacid and photosensitizer indocyanine green for enhanced chemo-photo combination therapy of hepatocellularcarcinoma, which could not only enhance the chemotherapy effect of sorafenib bowing to thesensitizing effect of ursolic acid, but also achieved synergetic phototherapy in virtue of indocyaninegreen. Besides, the nanoparticles could effectively delivery exogenous oxygen to tumor site and amelioratethe tumor hypoxic environment with the assistance of hemoglobin. The dual-sensitization drugdelivery system was expected to effectively reduce the resistance of traditional treatment methodsagainst tumor hypoxia, providing a novel prospect for the synergistic hepatocellular carcinomatreatment.

The effects of light colour on female rabbit reproductive performance and the expression of key genes in follicular development

Xiaoqing Pan,Xinglong Wang,Le Shao,Jie Yang,Feng Qin,Jian Li,Xia Zhang,Pin Zhai 한국축산학회 2022 한국축산학회지 Vol.64 No.3

The purpose of this study was to analyse the effects of light colour on rabbit reproductive performance and the expression of key follicular development genes. Rabbits (n = 1,068, 5 months old, 3.6–4.4 kg live body weight) were divided randomly into four groups, housed individually in wire mesh cages and exposed to red, green, blue, and white light-emitting diode (LED) light (control). The lighting schedule was 16 L : 8 D-15 d / 150 lx / 6:00 am–22:00 pm (3 d preartificial insemination to 12 d postartificial insemination). Red light and white light affected the conception rate and kindling rate and increased the total litter size at birth (p < 0.05). The effects of red light on litter size at weaning, litter weight at weaning, and individual weight at weaning increased compared with the green and blue groups. The effects of red light on live litter size at birth were increased compared with those in the blue group (p < 0.05). Compared to white light, green and blue light reduced the number of secondary follicles (p < 0.05). Compared to red light, green and blue light reduced the number of tertiary follicles (p < 0.05). Compared with white light, red LED light resulted in greater ovarian follicle stimulating hormone receptor and luteinizing hormone receptor mRNA expression (p < 0.05). Compared with green and blue LED light, red LED light resulted in greater B-cell lymphom-2 mRNA expression (p < 0.05). Compared with green LED light, red LED light inhibited FOXO1 mRNA expression in rabbit ovaries (p < 0.05). Red light can affect the reproductive performance of female rabbits and the expression of key genes for follicular development.

Expression and purification of anti-colorectal cancer monoclonal antibody CO17-1A in baculovirus infected insect cells

Jung-Hwan Lee,Deuk-Soo Kim,Yingxue Shao,Jun-Sik Yoon,Se-Ra Park,Yong-Seok Le,Yeon-Soo Han,Kyung-A Hwang,Young-Kug Choo,Kisung Ko 한국당과학회 2011 한국당과학회 학술대회 Vol.2011 No.1

In this study, we will attempt to analyze the ER localization, glycosylation pattern and anti-tumor activity of KDEL-fused monoclonal antibody. Advantages of the baculovirus insect cell expression system for production of recombinant proteins include high capacity, flexibility, and glycosylation capability. In this study, this expression system was exploited to produce anti-cancer monoclonal antibody (mAb) CO17-1A, which recognizes the antigen GA733 that is highly expressed on the surface membrane of colorectal carcinoma cells. The heavy chain (HC) and light chain (LC) genes of KDEL-fused mAb CO17-1A were cloned under the control of P10 and PPH promoters in the pFastBacTM dual vector, respectively. Gene expression cassettes carrying the HC and LC genes were transposed into a bacmid in Escherichia coli (DH10Bac). The transposed bacmid was transfected to Sf9 insect cells to generate baculovirus expressing mAb CO17-1A. In future, we will study the expression and localization of KDEL-fused mAb CO17-A in baculovirus infected cells by PCR, western blot, enzyme linked immunosorbent assay (ELISA), confocal immunofluorescence, fluorescence-activated cell sorting analysis (FACs) and antibody dependent cell cytotoxicity (ADCC).

Oligomeric Structure of the ATP-dependent Protease La (Lon) of Escherichia coli

박성철,Baolei Jia,양재경,Duyet Le Van,Yong Gi Shao,한상우,전영주,정진하,정강원 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.1

Lon, also known as protease La, belongs to a class of ATP-dependent serine protease. It plays an essential role in degradation of abnormal proteins and of certain short-lived regulatory proteins, and is thought to possess a Ser-Lys catalytic dyad. To examine the structural organization of Lon, we performed an electron microscope analysis. The averaged images of Lon with end-on orientation revealed a six-membered, ringshaped structure with a central cavity. The side-on view showed a two-layered structure with an equal distribution of mass across the equatorial plane of the complex. Since a Lon subunit possesses two large regions containing nucleotide binding and proteolytic domains, each layer of the Lon hexamer appears to consist of the side projections of one of the major domains arranged in a ring. Lon showed a strong tendency to form hexamers in the presence of Mg2+, but dissociated into monomers and/or dimers in its absence. Moreover, Mg2+-dependent hexamer formation was independent of ATP. These results indicate that Lon has a hexameric ring-shaped structure with a central cavity, and that the establishment of this configuration requires Mg2+, but not ATP.