Numerical study of complex modal characteristics in anguilliform mode of fish swimming

Zuo Cui,Hongzhou Jiang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

In nature, anguilliform fish swim fast and efficiently by undulating their elongate body in a specific way, which is generally described as a travelling wave. In present work, the undulatory motions of anguilliform fish are analyzed by the method of complex orthogonal decomposition (COD), and these particular motions are decomposed into two parts: the travelling component and standing component. The relative ratio between the travelling and standing components is defined as the travelling index, and the biological data show that anguilliform fish prefer to the undulatory motions with high travelling index (0.74-0.90). To study this phenomenon, a two-dimensional numerical model of anguilliform fish is developed by our proposed LSIB numerical method, in which the shape of fish body is described by level-set (LS) function, and the interactive force is demonstrated by the immersed boundary (IB) method. The results show that the net force is decreased slightly with the travelling index, but the efficiency is increased with the travelling index until it reached to 0.8, which is consistent with the biological observations. Besides, the influences of the oscillating amplitude, tail-beat frequency and Strouhal number are also discussed. Overall, the results in present study can be used to explain why anguilliform fish would like to select the swimming gaits with high travelling index.

Based on the Correlation of the File Dynamic Replication Strategy in Multi-Tier Data Grid

Zhongqiang Cui,Decheng zuo,Zhan Zhang 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.1

The data grid is one of the infrastructures for data and storage resource management. Data replication can improve data access performance, fault tolerance, and reduce network transmission bandwidth. As the site storage space is limited in the grid, how to effectively use grid resources become an important challenge. This paper introduces a dynamic grid replication algorithm based on popularity support and confidence (BPSC). Through the algorithm, data and its associated copy can be placed on a suitable site, with reduced access latency. Through Optorsim, simulation results show that the algorithm can provide better performance compared with other algorithms

Polydopamine Used as Hollow Capsule and Core-Shell Structures for Multiple Applications

Xinyu Cui,Yuanyuan Yin,Zuo Ma,Yongkui Yin,Yue Guan,Shengzhong Rong,Jinxia Gao,Yingying Niu,Miaojing Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.5

Polydopamine (PDA) capsule and core – shell structures with tailored structures and properties are of particular interests due to their multifunctions and potential applications as new colloidal structures in diverse fields. Among the available fabrication methods, PDA film onto colloidal particles followed by selective template removal has attracted extensive attention due to its advantages of precise control over the size, wall thickness and functions of the obtained capsules. The past several years has witnessed a rapid increase of research concerning the new fabrication strategies, functionalization and applications of this kind of capsules and core – shell structures, particularly in many fields such as drug delivery, catalysis, antibacterial, etc. In this review, the very recent progress of the capsule and core – shell structures based on PDA are summarized. There are basically two sections, including the fabrication process of PDA capsules, core – shell structures, and the various applications based on PDA.

Oxidation behavior of C/C composites with B4C-SiCZrC-ZrB2 coating prepared by infiltration and pyrolysis

Xiao-Hua Zuo,Zhi-Jun Dong,Guan-Ming Yuan,Zheng-Wei Cui,Xuan-Ke Li 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.1

Polycarbosilane, B-Si and B-Si-Zr modification coal tar pitch were used as impregnate agent for infiltration and pyrolysis formation of carbon/carbon (abbreviated as C/C) composites with B4C-SiC-ZrC-ZrB2 coating. The density of the composites was examined to be 1.0 g·cm-3, 1.4 g·cm-3 and 1.8 g·cm-3, respectively. The phase compositions, surface morphologies and element distributions of the coating were analyzed by X-ray diffraction (XRD) scanning electron microscopy (SEM) and energy dispervive spectroscopy (EDS), respectively. The result showed that the two composites with a density of 1.4 g·cm-3 and 1.8 g·cm-3 displayed compact microstructures. The oxidation behavior of the composites was studied by oxidation in air at temperatures from 800 to 1,550 ℃ for 1 h. The composites with a density of 1.8 g·cm-3 exhibited a lower weight loss of 1.8 % after oxidation. B4C-SiC-ZrC-ZrB2 coating was found to provide the best protection by the precipitated B2O3, SiO2 and ZrO2 on the surface of the composites during the oxidation process, which were characterized by self-healing and antioxidation. The C/C composites with B4C-SiC-ZrC-ZrB2 coating performed well at high temperatures with the formation of complex oxides glass film that prevented oxygen from further spreading into the matrix.

Syntheses, Structures, and Luminescence Properties of Two Copper(II) Complexes Constructed by Rigid Bis(triazole) and Nitrogen-containing Carboxylic Acid Ligands

Xiao-Xiao,Zuo-Xi Li,Bao-yi Yu,Guang-hua Cui 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.7

Two new copper(II) complexes with the formulas [Cu(btb)(pydc)(H2O)]n (1) and [Cu(btb)0.5(nph)(H2O)]n (2) have been synthesized under hydrothermal conditions by employing a rigid bis(triazole) ligand (btb = 4,4′-bis(1,2,4-triazolyl-1-yl)-biphenyl) and two carboxylic acids mixed ligands (H2pydc = pyridine-2,5-dicarboxylic acid and H2nph = 3-nitrophthalic acid). The copper atoms present different environments, with a tetragonal pyramidal geometry in 1 and octahedral configuration in 2. Complex 1 displays a dinuclear cluster, which is further packed into a 2D supramolecular layer by classical OH · · · O hydrogen bonds. Complex 2 possesses a trinodal 3,4,4-connected 3D framework with a rare sqc69 topology. In addition, thermal stability and luminescence property were investigated.

Effect of Trichostatin A on Anti HepG2 Liver Carcinoma Cells: Inhibition of HDAC Activity and Activation of Wnt/β-Catenin Signaling

Shi, Qing-Qiang,Zuo, Guo-Wei,Feng, Zi-Qiang,Zhao, Lv-Cui,Luo, Lian,You, Zhi-Mei,Li, Dang-Yang,Xia, Jing,Li, Jing,Chen, Di-Long Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Purpose: To investigate the effect of deacetylase inhibitory trichostatin A (TSA) on anti HepG2 liver carcinoma cells and explore the underlying mechanisms. Materials and Methods: HepG2 cells exposed to different concentrations of TSA for 24, 48, or 72h were examined for cell growth inhibition using CCK8, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under an inverted microscope. Expression of ${\beta}$-catenin, HDAC1, HDAC3, H3K9, CyclinD1 and Bax proteins was tested by Western blotting. Gene expression for ${\beta}$-catenin, HDAC1and HDAC3 was tested by q-PCR. ${\beta}$-catenin and H3K9 proteins were also tested by immunofluorescence. Activity of Renilla luciferase (pTCF/LEF-luc) was assessed using the Luciferase Reporter Assay system reagent. The activity of total HDACs was detected with a HDACs colorimetric kit. Results: Exposure to TSA caused significant dose-and time-dependent inhibition of HepG2 cell proliferation (p<0.05) and resulted in increased cell percentages in G0/G1 and G2/M phases and decrease in the S phase. The apoptotic index in the control group was $6.22{\pm}0.25%$, which increased to $7.17{\pm}0.20%$ and $18.1{\pm}0.42%$ in the treatment group. Exposure to 250 and 500nmol/L TSA also caused cell morphology changes with numerous floating cells. Expression of ${\beta}$-catenin, H3K9and Bax proteins was significantly increased, expression levels of CyclinD1, HDAC1, HDAC3 were decreased. Expression of ${\beta}$-catenin at the genetic level was significantly increased, with no significant difference in HDAC1and HDAC3 genes. In the cytoplasm, expression of ${\beta}$-catenin fluorescence protein was not obvious changed and in the nucleus, small amounts of green fluorescence were observed. H3K9 fluorescence protein were increased. Expression levels of the transcription factor TCF werealso increased in HepG2 cells following induction by TSA, whikle the activity of total HDACs was decreased. Conclusions: TSA inhibits HDAC activity, promotes histone acetylation, and activates Wnt/${\beta}$-catenin signaling to inhibit proliferation of HepG2 cell, arrest cell cycling and induce apoptosis.

A Coverage Algorithm for Multiple Autonomous Surface Vehicles in Flowing Environments

Weisheng Yan,Lei Zuo,Rongxin Cui,Jian Gao 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.2

This paper is concerned with the coverage problem with multiple autonomous surface vehicles (ASVs) intime-varying flowing environment, where the interest information distribution is unknown to the coverage networks. While taking the model parameter uncertainty into consideration, a decentralized, adaptive control law is proposedsuch that the coverage network will converge to the optimal assigned region from arbitrary positions. For easeof exploration, we first investigate the static coverage problem of two-agent systems in flowing environment andpresent an example by extending the two-agent systems into the general case. In addition, Gaussian Estimationis introduced to predict the value of the sensory function through the sampled measurements. By using the staticcoverage partition as theoretical foundation, we transform the optimal coverage control into the moving targettracking problems, where the target is the centroid of the assigned region for each ASV. Based on these techniques,a decentralized kinematic control algorithm is developed to navigate the multi-ASV systems. Furthermore, theadaptive back-stepping techniques are employed to extend the kinematic controller into dynamic case with uncertainmodel parameters. Finally, simulation studies are provided to demonstrate the feasibility and effectiveness of theproposed approaches.

Risk of venous thromboembolism in Chinese pregnant women: Hong Kong venous thromboembolism study

Duo Huang,Emmanuel Wong,Ming-Liang Zuo,Pak-Hei Chan,Wen-Sheng Yue,Hou-Xiang Hu,Ling Chen,Li-Xue Yin,Xin-Wu Cui,Ming-Xiang Wu,Xi Su,Chung-Wah Siu,Jo-Jo Hai 대한혈액학회 2019 Blood Research Vol.54 No.3

BackgroundPrevious Caucasian studies have described venous thromboembolism in pregnancy; however, little is known about its incidence during pregnancy and early postpartum peri-od in the Chinese population. We investigated the risk of venous thromboembolism in a “real-world” cohort of pregnant Chinese women with no prior history of venous thromboembolism.MethodsIn this observational study, 15,325 pregnancies were identified in 14,162 Chinese women at Queen Mary Hospital, Hong Kong between January 2004 and September 2016. Demographic data, obstetric information, and laboratory and imaging data were retrieved and reviewed.ResultsThe mean age at pregnancy was 32.4±5.3 years, and the median age was 33 years (interquartile range, 29‒36 yr). Pre-existing or newly diagnosed diabetes mellitus was present in 627 women (4.1%); 359 (0.7%) women had pre-existing or newly detected hypertension. There was a small number of women with pre-existing heart disease and/or rheumatic conditions. Most deliveries (86.0%) were normal vaginal; the remaining were Cesarean section 2,146 (14.0%). The incidence of venous thromboembolism was 0.4 per 1,000 pregnancies, of which 83.3% were deep vein thrombosis and 16.7% were pul-monary embolism. In contrast to previous studies, 66.7% of venous thrombosis occurred in the first trimester.ConclusionChinese women had a substantially lower risk of venous thromboembolism during preg-nancy and the postpartum period compared to that of Caucasians. The occurrence of pregnancy-related venous thromboembolism was largely confined to the early preg-nancy period, probably related to the adoption of thromboprophylaxis, a lower rate of Cesarean section, and early mobilization.

Effects of dietary Enteromorpha powder on reproduction-related hormones and genes during the late laying period of Zi geese

Ma Wei Qing,Zhao Dan Hua,Cheng Huang Zuo,Wang Si Bo,Yang Ji,Hong Xia Cui,Lu Ming Yuan,Wu Hong Zhi,Xu Li,Liu Guo Jun 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.3

Objective: The aim of this study was to investigate the effects of Enteromorpha powder supplementation on reproduction-related hormones and genes in the late laying period of Zi geese. Methods: A total of 312 (1-year-old) Zi geese with similar laying rate were randomly divided into 2 groups with 6 replicates each, each with 21 female geese and 5 male geese. The control group was fed with a basal diet and the test group was fed with a diet containing 3% Enteromorpha powder. The trial period lasted for 7 weeks. Results: Our results showed that the laying rate was improved in the test group at each week of trial (p<0.01), and the levels of estradiol in serum and prolactin in ovary were increased compared with the control group (p<0.05). Conclusion: Based on above results, Enteromorpha powder supplementation at 3% could promote reproductive performance during the late laying period of Zi geese. Objective: The aim of this study was to investigate the effects of Enteromorpha powder supplementation on reproduction-related hormones and genes in the late laying period of Zi geese.Methods: A total of 312 (1-year-old) Zi geese with similar laying rate were randomly divided into 2 groups with 6 replicates each, each with 21 female geese and 5 male geese. The control group was fed with a basal diet and the test group was fed with a diet containing 3% <i>Enteromorpha</i> powder. The trial period lasted for 7 weeks.Results: Our results showed that the laying rate was improved in the test group at each week of trial (p<0.01), and the levels of estradiol in serum and prolactin in ovary were increased compared with the control group (p<0.05).Conclusion: Based on above results, <i>Enteromorpha</i> powder supplementation at 3% could promote reproductive performance during the late laying period of Zi geese.