Numerical study of the run-up of a solitary wave after propagation over a saw-tooth-shaped submerged breakwater

Sun, Jiawen,Ma, Zhe,Wang, Dongxu,Dong, Sheng,Zhou, Ting The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

A numerical model is established to investigate the run-up of a solitary wave after propagating over a triangular saw-tooth-shaped submerged breakwater. A rectangular-shaped submerged breakwater is simulated for comparison. Several factors, including the submerged depth, the lagoon length and the beach slope, are selected as independent variables. The free surface motions and velocity fields of the solitary wave interacting with the submerged breakwater are discussed. The results show that the submerged depth and lagoon length play significant roles in reducing the run-up. The influence of the beach slope is not significant. At the same submerged depth, the triangular saw-tooth-shaped submerged breakwater has only a slightly better effect than the rectangular-shaped submerged breakwater on the run-up reduction. However, a calmer reflected wave profile could be obtained with the rougher surface of the saw-tooth-shaped submerged breakwater. The study conclusions are expected to be useful for the conceptual design of saw-tooth-shaped submerged breakwaters.

Numerical study of the run-up of a solitary wave after propagation over a saw-tooth-shaped submerged breakwater

Sun, Jiawen,Ma, Zhe,Wang, Dongxu,Dong, Sheng,Zhou, Ting The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

A numerical model is established to investigate the run-up of a solitary wave after propagating over a triangular saw-tooth-shaped submerged breakwater. A rectangular-shaped submerged breakwater is simulated for comparison. Several factors, including the submerged depth, the lagoon length and the beach slope, are selected as independent variables. The free surface motions and velocity fields of the solitary wave interacting with the submerged breakwater are discussed. The results show that the submerged depth and lagoon length play significant roles in reducing the run-up. The influence of the beach slope is not significant. At the same submerged depth, the triangular saw-tooth-shaped submerged breakwater has only a slightly better effect than the rectangular-shaped submerged breakwater on the run-up reduction. However, a calmer reflected wave profile could be obtained with the rougher surface of the saw-tooth-shaped submerged breakwater. The study conclusions are expected to be useful for the conceptual design of saw-tooth-shaped submerged breakwaters.

Mxene structure: A key parameter in corrosion barrier performance of organic coatings

Ziyang Zhou,Sepideh Pourhashem,Zhengquan Wang,Jiawen Sun,Xiaohong Ji,Xiaofan Zhai,Jizhou Duan,Baorong Hou 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

In this research, the effects of fresh and oxidized MXene on the surface, adhesion, and corrosion-resistantproperties of waterborne epoxy coatings are considered. The oxidized MXene is prepared through storageof fresh MXene nanosheets in an open vial for 1 month. The results confirm that the waterborne epoxycoating loaded with silane functionalized fresh MXene nanosheets (epoxy/F-MXene) has significantlyhigher barrier performance and anti-corrosion behavior than the sample modified with silane functionalizedoxidized MXene nanosheets (epoxy/F-O-MXene). Indeed, the F-MXene nanosheets (with defectfreeand large two dimensional morphology) are able to effectively inhibit the path of corrosive mediaas well as increment the epoxy matrix compactness compared to the F-O-MXene (with broken nanosheetmorphology composed of TiO2 nanoparticles) due to rapid oxidation of the MXene nanosheets in theenvironment. Besides, the epoxy/F-MXene nanocomposite coating has slightly higher water contact angleand adhesion strength to the metallic substrate compared to the epoxy/F-O-MXene. The results of thisresearch clearly reveal the importance of preventing MXene oxidation before application as nanofillerin the polymer coatings.

Changes in Gene Expression of Actinobacillus pleuropneumoniae in Response to Anaerobic Stress Reveal Induction of Central Metabolism and Biofilm Formation

Lu Li,Jiawen Zhu,Kui Yang,Zhuofei Xu,Ziduo Liu,Rui Zhou 한국미생물학회 2014 The journal of microbiology Vol.52 No.6

Actinobacillus pleuropneumoniae is an important porcinerespiratory pathogen causing great economic losses in thepig industry worldwide. Oxygen deprivation is a stress thatA. pleuropneumoniae will encounter during both early infectionand the later, persistent stage. To understand modulationof A. pleuropneumoniae gene expression in responseto the stress caused by anaerobic conditions, gene expressionprofiles under anaerobic and aerobic conditions werecompared in this study. The microarray results showed that631 genes (27.7% of the total ORFs) were differentially expressedin anaerobic conditions. Many genes encoding proteinsinvolved in glycolysis, carbon source uptake systems,pyruvate metabolism, fermentation and the electron respirationtransport chain were up-regulated. These changes ledto an increased amount of pyruvate, lactate, ethanol and acetatein the bacterial cells as confirmed by metabolite detection. Genes encoding proteins involved in cell surface structures,especially biofilm formation, peptidoglycan biosynthesisand lipopolysaccharide biosynthesis were up-regulatedas well. Biofilm formation was significantly enhancedunder anaerobic conditions. These results indicate that inductionof central metabolism is important for basic survivalof A. pleuropneumoniae after a shift to an anaerobic environment. Enhanced biofilm formation may contribute tothe persistence of this pathogen in the damaged anaerobichost tissue and also in the early colonization stage. Thesediscoveries give new insights into adaptation mechanismsof A. pleuropneumoniae in response to environmental stress.

TGF-β1/IL-11/MEK/ERK signaling mediates senescence-associated pulmonary fibrosis in a stress-induced premature senescence model of Bmi-1 deficiency

Haiyun Chen,Jialong Liang,Xin Gu,Jiawen Zhou,Chunfeng Xie,Xianhui Lv,Rong Wang,Qing Liu,Zhiyuan Mao,Haijian Sun,Guoping Zuo,Dengshun Miao,Jianliang Jin 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

To study whether TGF-β1/IL-11/MEK/ERK (TIME) signaling mediates senescence-associated pulmonary fibrosis (SAPF) in Bmi-1-deficient (Bmi-1−/−) mice and determines the major downstream mediator of Bmi-1 and crosstalk between p16INK4a and reactive oxygen species that regulates SAPF, phenotypes were compared among 7-week-old p16INK4a and Bmi-1 double-knockout, N-acetylcysteine (NAC)-treated Bmi-1−/−, Bmi-1−/−, and wild-type mice. Pulmonary fibroblasts and alveolar type II epithelial (AT2) cells were used for experiments. Human pulmonary tissues were tested for type Ι collagen, α-smooth muscle actin (α-SMA), p16INK4a, p53, p21, and TIME signaling by using enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that Bmi-1 deficiency resulted in a shortened lifespan, ventilatory resistance, poor ventilatory compliance, and SAPF, including cell senescence, DNA damage, a senescence-associated secretory phenotype and collagen overdeposition that was mediated by the upregulation of TIME signaling. The signaling stimulated cell senescence, senescence-related secretion of TGF-β1 and IL-11 and production of collagen 1 by pulmonary fibroblasts and the epithelial-to-mesenchymal transition of AT2 cells. These processes were inhibited by anti-IL-11 or the MEK inhibitor PD98059. NAC treatment prolonged the lifespan and ameliorated pulmonary dysfunction and SAPF by downregulating TIME signaling more than p16INK4a deletion by inhibiting oxidative stress and DNA damage and promoting ubiquitinproteasome degradation of p16INK4a and p53. Cytoplasmic p16INK4a accumulation upregulated MEK/ERK signaling by inhibiting the translocation of pERK1/2 (Thr202/Tyr204) from the cytoplasm to the nucleus in senescent fibroblasts. The accumulation of collagen 1 and α-SMA in human lungs accompanied by cell senescence may be mediated by TIME signaling. Thus, this signaling in aging fibroblasts or AT2 cells could be a therapeutic target for preventing SAPF.

High speed intravascular photoacoustic imaging with fast optical parametric oscillator laser at 1.7 <i>μ</i>m

Piao, Zhonglie,Ma, Teng,Li, Jiawen,Wiedmann, Maximilian T.,Huang, Shenghai,Yu, Mingyue,Kirk Shung, K.,Zhou, Qifa,Kim, Chang-Seok,Chen, Zhongping American Institute of Physics 2015 Applied Physics Letters Vol.107 No.8

<P>Intravascular photoacoustic imaging at 1.7 mu m spectral band has shown promising capabilities for lipid-rich vulnerable atherosclerotic plaque detection. In this work, we report a high speed catheter-based integrated intravascular photoacoustic/intravascular ultrasound (IVPA/IVUS) imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A lipid-mimicking phantom and atherosclerotic rabbit abdominal aorta were imaged at 1 frame per second, which is two orders of magnitude faster than previously reported in IVPA imaging with the same wavelength. Clear photoacoustic signals by the absorption of lipid rich deposition demonstrated the ability of the system for high speed vulnerable atherosclerotic plaques detection. (C) 2015 AIP Publishing LLC.</P>

Identification of drug target candidates of the swine pathogen Actinobacillus pleuropneumoniae by construction of protein–protein interaction network

Siqi Li,Zhipeng Su,Chengjun Zhang,Zhuofei Xu,Xiaoping Chang,Jiawen Zhu,Ran Xiao,Lu Li,Rui Zhou 한국유전학회 2018 Genes & Genomics Vol.40 No.8

Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae has led to severe economic losses in the pig industry worldwide. A. pleuropneumoniae displays various levels of antimicrobial resistance, leading to the dire need to identify new drug targets. Protein–protein interaction (PPI) network can aid the identification of drug targets by discovering essential proteins during the life of bacteria. The aim of this study is to identify drug target candidates of A. pleuropneumoniae from essential proteins in PPI network. The homologous protein mapping method (HPM) was utilized to construct A. pleuropneumoniae PPI network. Afterwards, the subnetwork centered with H-NS was selected to verify the PPI network using bacterial two-hybrid assays. Drug target candidates were identified from the hub proteins by analyzing the topology of the network using interaction degree and homologous comparison with the pig proteome. An A. pleuropneumoniae PPI network containing 2737 non-redundant interaction pairs among 533 proteins was constructed. These proteins were distributed in 21 COG functional categories and 28 KEGG metabolic pathways. The A. pleuropneumoniae PPI network was scale free and the similar topological tendencies were found when compared with other bacteria PPI network. Furthermore, 56.3% of the H-NS subnetwork interactions were validated. 57 highly connected proteins (hub proteins) were identified from the A. pleuropneumoniae PPI network. Finally, 9 potential drug targets were identified from the hub proteins, with no homologs in swine. This study provides drug target candidates, which are promising for further investigations to explore lead compounds against A. pleuropneumoniae.