Hispidin attenuates bleomycin‑induced idiopathic pulmonary fibrosis via an anti‑oxidative effect in A549 cells

Ren Chen-Xi,Jin Xin,Xie Dan-Ping,Guo Xiao-Yu,Yu Li-Yun,Cui Yu-Dong,Kwon Taeho,Sun Hu-Nan 한국응용생명화학회 2021 Applied Biological Chemistry (Appl Biol Chem) Vol.64 No.5

Idiopathic pulmonary fibrosis (IPF) is a serious and irreversible chronic lung disease. Bleomycin (BLM) is an anticancer drug, which can cause severe lung toxicity. The main target of oxidative stress-induced lung injury is alveolar epithelial cells, which lead to interstitial fibrosis. The present study investigated whether hispidin (HP), which has excellent antioxidant activity, attenuates bleomycin-induced pulmonary fibrosis via anti-oxidative effects in A549 cells. We found that hispidin reduced bleomycin-induced fibrosis of A549 cells by reducing reactive oxygen species (ROS) levels and inhibiting epithelial-mesenchymal transition. Taken together, our data suggest that hispidin has therapeutic potential in preventing bleomycin-induced pulmonary fibrosis.

Boundary Layer and Cooling Rate and Microstructure Formation on the Cooling Sloping Plate

Ren Guo Guan,Zhan Yong Zhao,Run Ze Chao,Lei Dong,이종수,Chun Ming Liu 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5

During melt treatment by cooling sloping plate, laminar flow and turbulent flow exist on sloping plate surface commonly. The thickness of velocity boundary layer and the critical transfer distance from laminar flow to turbulent flow increase with the decrease of initial flow velocity. The thickness of temperature boundary layer increases with the increment of flow distance and the decrease of initial flow velocity. The melt cooling rate and melt thickness have an inverse proportion relationship. The melt cooling rate of cooling sloping plate process can reach 102-103 K/s and belongs to meta-rapid solidification scope. Uniform solute field and high cooling rate can lead to eruptive nucleation. In addition, a large quantity of heterogonous nuclei appears on the sloping plate surface, and vibrating flow can enable heterogonous nucleus to escape off the plate, which leads to nucleus multiplication. Under relative uniform solute field and high cooling rate, some grains can keep stable growth surface, go on growing with the round surface and finally maintain their globular structure. However, there are always some grains that grow along a certain preferred direction, but under vibrating flow their dendritic arms break and transform into near spherical structure.

Effect of metallic copper on the electrothermal properties of carbon nanofibers

He‑Dong Huang,Hao Pu,Jun‑Wei Fan,Bing Su,Hong‑Yang Liu,Xin‑Yi Ha,Yong‑Fei Ren,Ze‑yu Guo 한국탄소학회 2024 Carbon Letters Vol.34 No.4

Pipeline Pull-Back Load Analysis by Continuous Beam Theory

Zhengwei Guo,Shuai Xie,Liancheng Ren,Chaoqun Dong,Yinchun Gong 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.4

Pipeline pull-back load is an important basis for selecting power and checking capability of drilling equipment. In this paper, mechanical models of the pipeline hoisting outside and pulling inside the hole are established by the continuous beam theory, and relationships among various parameters are analyzed in the process of pull-back pipeline. The results show that there is a linear relationship between the lifting height of basket and the entry angle of hole. During the construction of the hoisting pipeline, the bending moment and shearing force of the basket position near the hole are larger, so the strength check of the pipeline only needs to do at this position. There is a linear relationship between the lifting height of the basket and the length of spanning pipeline. The lifting load and axial force of the pipeline vary linearly. The pull-back load of the pipeline varies curve in the arc segment of the trajectory. The pipeline pull-back load varies linearly in linear segment of trajectory.

A TYPE OF MODIFIED BFGS ALGORITHM WITH ANY RANK DEFECTS AND THE LOCAL Q-SUPERLINEAR CONVERGENCE PROPERTIES

Ge, Ren-Dong,Xia, Zun-Quan,Qiang, Guo 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.22 No.1

A modified BFGS algorithm for solving the unconstrained optimization, whose Hessian matrix at the minimum point of the convex function is of rank defects, is presented in this paper. The main idea of the algorithm is first to add a modified term to the convex function for obtain an equivalent model, then simply the model to get the modified BFGS algorithm. The superlinear convergence property of the algorithm is proved in this paper. To compared with the Tensor algorithms presented by R. B. Schnabel (seing [4],[5]), this method is more efficient for solving singular unconstrained optimization in computing amount and complication.

Robust H-infinity Estimation for Linear Time-Delay Systems: An Improved LMI Approach

Ai-Guo Wu,Jin Dong,Guang-Ren Duan 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.4

The problem of robust H∞ estimation for the polytopic uncertain linear system with state delay is considered. Firstly, by introducing two auxiliary matrices a new LMI representation of H∞ performance is presented for the linear systems with a single time-varying state delay. The proposed criterion exhibits a kind of separation between the system matrices and the positive definite Lyapunov matrices. So the vertex-dependent Lyapunov functions can be adopted, and thus a less conservative re-sult is expected to be obtained.

Integrated wear prediction model for cylindrical gear with variable hyperbolic circular arc tooth trace under mixed elastohydrodynamic lubrication

Yongqiao Wei,Dong Yang,Rui Guo,Zhongtao Ren,Zeyu Li,Lan Luo 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

Cylindrical gear with variable hyperbolic circular arc tooth trace (VH-CATT) is a new type of gear. Sliding wear is the main mode of the surface failure of multiple mechanical parts. Both the lubrication state and contact temperature considerably influence wear characteristics, which may aggravate the transmission performance of gear pairs. Wear, contact temperature, as well as lubrication states are jointly explored. Therefore, an integrated wear prediction model was proposed through taking into account flash contact temperature and surface roughness of VH-CATT cylindrical gears in mixed elastohydrodynamic lubrication. According to the equivalent ellipse contact model of VH-CATT cylindrical gears and tooth surface equation, normal curvature and velocity relations for VH-CATT cylindrical gears were observed, and the normal meshing force was obtained through the consideration of load sharing coefficients and quality grades. Flash contact temperature was estimated by using the literature. This study proposes analytical solutions for investigating how various surface roughness, operation, and geometric parameters affect asperity contact ratio (ACR), asperity contact pressure (ACP), flash contact temperature (FCT), as well as wear depth (WD) related to driving gears. ACR, ACP, FCT, as well as WD initially decrease and then increase from engaging-in to engagingout processes. The minimum occurs at the pitch point. The WD declines as module, cutter radius, and rotational velocity increase while augmenting when surface roughness and torques increase. The maximum and minimum wear depths in driving gears occur at the dedendum and pitch point, respectively. Its overall wear is reduced by 23.16 % compared to the wear of spur gears. The results are valuable for the studies of tooth pitting, wear resistance, and fatigue life improvement for VH-CATT cylindrical gear. These studies can provide verification data and references required for engineering designs and VH-CATT cylindrical gear operations.

Subcellular Characterization of Porcine Oocytes with Different Glucose-6-phosphate Dehydrogenase Activities

Fu, Bo,Ren, Liang,Liu, Di,Ma, Jian-Zhang,An, Tie-Zhu,Yang, Xiu-Qin,Ma, Hong,Zhang, Dong-Jie,Guo, Zhen-Hua,Guo, Yun-Yun,Zhu, Meng,Bai, Jing Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.12

The in vitro maturation (IVM) efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+) oocytes with low glucose-6-phosphate dehydrogenase (G6PDH) activity have shown superior quality than BCB negative (-) oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG) migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9) and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB- oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.

Disease vector occurrence and ecological characteristics of chiggers on the chestnut white-bellied rat Niviventer fulvescens in Southwest China between 2001 and 2019

Yan-Ling Chen,Xian-Guo Guo,Wen-Yu Song,Tian-Guang Ren,Lei Zhang,Rong Fan,Cheng-Fu Zhao,Zhi-Wei Zhang,Wenge Dong,Xiao-Bin Huang,Dao-chao Jin 대한기생충학ㆍ열대의학회 2023 The Korean Journal of Parasitology Vol.61 No.3

Chigger mites are the vector of scrub typhus. This study estimates the infestation status and ecological characteristics of chiggers on the chestnut white-bellied rat Niviventer fulvescens in Southwest China between 2001 and 2019. Chiggers were identified under the microscope, and infestation indices were calculated. The Preston’s log-normal model was used to fit the curve of species abundance distribution. A total of 6,557 chiggers were collected in 136 of 342 N. fulvescens rats, showing high overall infestation indices (prevalence=39.8%, mean abundance=19.2, mean intensity=48.2) and high species diversity (S =100, H’=3.0). Leptotrombidium cangjiangense, Neotrombicula japonica, and Ascoschoengastia sifanga were the three dominant chigger species (constituent ratio=42.9%; 2,736/6,384) and exhibited an aggregated distribution among different rat individuals. We identified 100 chigger species, with 3 of them (Leptotrombidium scutellare, Leptotrombidium wenense, and Leptotrombidium deliense) as the main vectors of scrub typhus in China and nine species as potential vectors of this disease. Disease vector occurrence on N. fulvescens may increase the risk of spreading scrub typhus from rats to humans. Chigger infestation on N. fulvescens varied significantly in different environments. The species abundance distribution showed a log-normal distribution pattern. The estimated number of chigger species on N. fulvescens was 126 species.

Microstructure Formation Mechanism and Properties of AZ61 Alloy Processed by Melt Treatment with Vibrating Cooling Slope and Semisolid Rolling

Zhan Yong Zhao,Ren Guo Guan,Xiang Wang,Yang Li,Lei Dong,이종수,Chun Ming Liu 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5

A melt treatment with a vibrating cooling slope and a semisolid rolling process to produce an AZ61 alloy strip was proposed. The microstructure formation mechanism and the properties of the AZ61 alloy produced by the proposed process were investigated. Due to the high cooling rate and stirring action caused by the vibration cooling slope, the nucleation rate was greatly improved, which caused the formation of fine spherical or rosette primary grains. During the rolling process, the solid fraction increased from the entrance to the exit of the roll gap, and under the shearing action of the roller, the distribution of solute in the melt was homogenous, and the primary grains grew further. When the casting temperature was 680 °C,a strip with a cross section of 4 mm×160 mm was produced and a homogeneous microstructure was obtained. The ultimate tensile strength of the AZ61 alloy strip produced by the proposed method reached 242 MPa, and the corresponding elongation to failure was 4%, which were better than those achieved in previous similar studies.