The Specific Case Analysis of Biomineralization Induced by Sulfate Reducing Bacteria

( Hongwei Liu ),( Shuang Qin ),( Chaoyang Fu ),( Fei Xiao ),( Deli Wang ),( Xia Han ),( Tianli Wang ),( Hongfang Liu ) 한국부식방식학회(구 한국부식학회) 2017 Corrosion Science and Technology Vol.16 No.6

The effects of sulfate reducing bacteria (SRB) on the corrosion and scaling of the Q235 carbon steel has been investigated in the simulated sewage water and oil field gathering pipelines production water, using scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDS), and three-dimensional stereoscopic microscope. Results indicated that the concentration of SRB reached the maximum value on the ninth day in simulated sewage water with a large amount of scaling on the surface of specimen. In oil field gathering pipelines, a large amount of scaling and mineralization of mineral salts and thick deposition of extracellular polymeric substance (EPS) layers were also observed on the surface of specimen. The thickness of biofilm was about 245 μm within 30 days. After adding microbicides, the thickness of corrosion products film was only up to 48 - 106 μm within 30 days, suggesting that SRB could induce biomineralization. Under-deposit corrosion morphology was uniform in the absence of microbicides while local corrosion was observed in the presence of microbicides.

Psoralen synergies with zinc implants to promote bone repair by regulating ZIP4 in rats with bone defect

Meijing Liu,Junlong Tan,Shuang Li,Chaoyang Sun,Xiangning Liu,Hongtao Yang,Xiaogang Wang 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background The regulation of dose-dependent biological effects induced by biodegradation is a challenge for the production of biodegradable bone-substitute materials, especially biodegradable zinc (Zn) -based materials. Cytotoxicity caused by excess local Zn ions (Zn2+) from degradation is one of the factors limiting the wide application of Zn implants. Given that previous studies have revealed that delayed degradation of Zn materials by surface modification does not reduce cytotoxicity; in the present study, we explore whether preventing the entry of excess Zn2+ into cells may can reduce local Zn toxicity by applying Psoralen (PRL) to Zn implants and assessing its ability to regulate intracellular Zn2+ concentrations. Methods The effects of different concentrations of Zn2+ on cellular activity and cytotoxicity were investigated; briefly, we identified natural compounds that regulate Zn transporters, thereby regulating the concentrations of intracellular Zn2+, and applied them to Zn materials. Of these materials, PRL, a natural, tricyclic, coumarin-like aromatic compound that promotes the proliferation and differentiation of osteoblasts and enhances osteogenic activity, was loaded onto the surface of a Zn material using peptides and chitosan (CS), and the surface characteristics, electrochemical properties, and activity of the modified Zn material were evaluated. In addition, the ability of Zn + CS/pPRL implants to promote bone formation and accelerate large-scale bone defect repairs was assessed both in vitro and in vivo. Results We determined that 180 μM Zn2+ significantly induced pre-osteoblast cytotoxicity, and a 23-fold increase in Zrt- and Irt-like protein 4 (ZIP4) expression. We also found that PRL dynamically regulates the expression of ZIP4 in response to Zn2+ concentration. To address the problem of cytotoxicity caused by excessive Zn2+ in local Zn implants, PRL was loaded onto the surface of Zn implants in vivo using peptides and CS, which dynamically regulated ZIP4 levels, maintained the balance of intracellular Zn2+ concentrations, and enhanced the osteogenic activity of Zn implants. Conclusions This study reveals the importance of Zn2+ concentration when using Zn materials to promote bone formation and introduces a natural active ingredient, PRL, that can regulate intracellular Zn2+ levels, and thus may be clinically applicable to Zn implants for the treatment of critical bone defects.

Robot Search Path Planning Method Based on Prioritized Deep Reinforcement Learning

Yanglong Liu,Zuguo Chen,Ming Lu,Chaoyang Chen,Xuzhuo Zhang,Yonggang Li 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

The path planning process of the robot relies too much on environmental information, which makes it difficult to obtain the optimal search path when the search and rescue tasks are carried out in a complex postdisaster environment. Thus, a path planning method based on prioritized deep reinforcement learning is proposed in the paper. The core idea of the method is that the robot first builds an environment mathematical model based on the obtained information through the sensors. Then, to make the robot can obtain the optimal search policy in an extremely complex environment, the prioritized replay mechanism is used to improve deep reinforcement learning. Finally, the simulation results show that the search path planning method based on prioritized deep reinforcement learning proposed can not only improve the convergence speed of the model but also is endowed good robustness in this paper.

Visualization Analysis of Eco-tourism Resources Development Research in China Based on Citespace

Fan Gang,Liu Chaoyang 아시아사회과학학회 2021 Jornal of Asia Social Science Vol.5 No.3

This paper analyzes the hot spots and cutting-edge topics in the research field of ecotourism resources development in China in recent 10 years, so as to facilitate relevant researchers to understand the research status in this field. Taking the academic papers related to the development and research of ecotourism resources in China from 2010 to 2019 in the Web of Science database as the research object, the co-occurrence of authors, countries, institutions and subject words was analyzed by using the bibliometric visualization software CiteSpace. A total of 13,820 research papers on the development of China s ecotourism resources were published in the search scope, and the number of published papers showed an increasing trend year by year, which attracted wide attention from many disciplines and fields. In recent years, Chinese researchers have carried out extensive and in-depth research on the development of ecotourism resources from various disciplines and fields.

Mangiferin ameliorates cardiac fibrosis in D-galactose-induced aging rats by inhibiting TGF-β/p38/MK2 signaling pathway

Jing Cheng,Chaoyang Ren,Renli Cheng,Yunning Li,Ping Liu,Wei Wang,Li Liu 대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.3

Doxorubicin-Loaded CuS Nanoparticles Conjugated with GFLG: A Novel Drug Delivery System for Lymphoma Treatment

Ying Jiang,Chaoyang Guan,Xu Liu,Yushan Wang,Huaqin Zuo,Tian Xia,Peipei Xu,Jian Ouyang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.1

Doxorubicin (DOX) plays an important part in lymphoma treatment. However, various side effects on normal tissues restrict its clinical use. Nanocarriers connected by Gly–Phe–Leu–Gly (GFLG) can be equipped with the advantages of nanoparticles (NPs), their enhanced permeability and retention (EPR) effect, and surface modifiability. Nanocarriers can also be specifically enzymatically hydrolyzed by cathepsin (Cath) B, a kind of enzyme highly expressed in tumor cells. In this work, we proposed a novel drug delivery system comprising GFLG conjugated with copper sulfide (CuS) NPs loaded with DOX. The system, designated as CuS-GFLG-DOX, could be used for NP-based targeted combination chemotherapy. Results showed that the drug delivery system had an appropriate diameter, good dispersibility, high encapsulation efficiency and high drug loading. The system also exhibited an excellent targeting of lymphoma cells and an enhanced antitumor activity. The possible pathway to induce cytotoxic effects was Bcl-2/caspase-mediated apoptosis pathway. In conclusion, CuS-GFLG-DOX could precisely deliver drugs to lymphoma cells and could be a novel and promising therapeutic option for lymphoma.

Low Chattering Trajectory Tracking Control of Non-singular Fast Terminal Sliding Mode Based on Disturbance Observer

Jiqing Chen,Chaoyang Zhao,Qingsong Tang,Xu Liu,Zhikui Wang,Chengzhi Tan,Jiahua Wu,Teng Long 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.2

The improvement of the performance of the multi-joint manipulator control system is of great significance to improve the level of industrial automation. The existing sliding mode control methods are difficult to ensure the high-precision and fast-tracking of joints of a manipulator to the desired trajectory under low chattering control input. Therefore, a non-singular fast terminal sliding mode control method based on a nonlinear disturbance observer is proposed. In addition, a new non-singular fast terminal sliding mode surface is designed. The performance comparison method of the sliding mode surface proves its better control quality. Aiming at the problem of serious chattering, the nonlinear disturbance observer technology, and saturation function method are introduced to effectively weaken the chattering. Finally, taking the 3-DOF manipulator as the research object, a comparative simulation experiment is carried out in the MATLAB / Simulink environment. The results show that under the uncertainty of modeling error, external disturbance, and joint friction, the designed control method not only solves the problems of singular control input and serious chattering but also realizes the high-precision and fast-tracking of each joint to the desired trajectory. Thus, the effectiveness and feasibility of the design method are verified. The improvement of the performance of the multi-joint manipulator control system is of great significance to improve the level of industrial automation. The existing sliding mode control methods are difficult to ensure the high-precision and fast-tracking of joints of a manipulator to the desired trajectory under low chattering control input. Therefore, a non-singular fast terminal sliding mode control method based on a nonlinear disturbance observer is proposed. In addition, a new non-singular fast terminal sliding mode surface is designed. The performance comparison method of the sliding mode surface proves its better control quality. Aiming at the problem of serious chattering, the nonlinear disturbance observer technology, and saturation function method are introduced to effectively weaken the chattering. Finally, taking the 3-DOF manipulator as the research object, a comparative simulation experiment is carried out in the MATLAB / Simulink environment. The results show that under the uncertainty of modeling error, external disturbance, and joint friction, the designed control method not only solves the problems of singular control input and serious chattering but also realizes the high-precision and fast-tracking of each joint to the desired trajectory. Thus, the effectiveness and feasibility of the design method are verified.

Mangiferin ameliorates cardiac fibrosis in D-galactose-induced aging rats by inhibiting TGF-β/p38/MK2 signaling pathway

Cheng, Jing,Ren, Chaoyang,Cheng, Renli,Li, Yunning,Liu, Ping,Wang, Wei,Liu, Li The Korean Society of Pharmacology 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.2

Aging is the process spontaneously occurred in living organisms. Cardiac fibrosis is a pathophysiological process of cardiac aging. Mangiferin is a well-known C-glucoside xanthone in mango leaves with lots of beneficial properties. In this study, rat model of cardiac fibrosis was induced by injected with 150 mg/kg/d D-galactose for 8 weeks. The age-related cardiac decline was estimated by detecting the relative weight of heart, the serum levels of cardiac injury indicators and the expression of hypertrophic biomakers. Cardiac oxidative stress and local inflammation were measured by detecting the levels of malondialdehyde, enzymatic antioxidant status and proinflammatory cytokines. Cardiac fibrosis was evaluated by observing collagen deposition via masson and sirius red staining, as well as by examining the expression of extracellular matrix proteins via Western blot analysis. The cardiac activity of profibrotic TGF-β1/p38/MK2 signaling pathway was assessed by measuring the expression of TGF-β1 and the phosphorylation levels of p38 and MK2. It was observed that mangiferin ameliorated D-galactose-induced cardiac aging, attenuated cardiac oxidative stress, inflammation and fibrosis, as well as inhibited the activation of TGF-β1/p38/MK2 signaling pathway. These results showed that mangiferin could ameliorate cardiac fibrosis in D-galactose-induced aging rats possibly via inhibiting TGF-β/p38/MK2 signaling pathway.

An Adaptive Timer Handoff Algorithm Based on Handoff Hysteresis

Weihong Cai,Junhua Liu,Chaoyang Lei,Xia Fang 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.4

Contrast-enhanced ultrasonography-based renal blood perfusion in brain-dead donors predicts early graft function

Weiming He,Yuguang Xu,Chaoyang Gong,Xiaozhen Liu,Yuqiang Wu,Xi Xie,Jiazhen Chen,Yi Yu,Zhiyong Guo,Qiang Sun 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.4

Purpose: The aim of this study was to quantify renal microcirculatory perfusion in braindead donors using contrast-enhanced ultrasonography (CEUS), and to establish an accurate, noninvasive, and convenient index for predicting delayed graft function (DGF) post-transplantation. Methods: In total, 90 brain-dead donor kidneys (training group, n=60; validation group, n=30) examined between August 2020 and November 2022 were recruited in this prospective study. CEUS was performed on the kidneys of brain-dead donors 24 hours before organ procurement and time-intensity curves were constructed. The main measures were arrival time, time to peak, and peak intensity of the kidney segmental arteries, cortex, and medulla. Recipients were divided into DGF and non-DGF groups according to early post-transplant graft function. The area under the receiver operating characteristic curve (AUC) was used to assess diagnostic performance. Results: The arrival time of the kidney segmental artery and cortex and the time interval between the time to peak of the segmental artery and cortex were identified as independent factors associated with DGF by multivariate stepwise regression analysis. A new index for the joint prediction model of three variables, the contrast-enhanced ultrasonography/Kidney Donor Profile index (CEUS-KDPI), was developed. CEUS-KDPI showed high accuracy for predicting DGF (training group: AUC, 0.91; sensitivity, 90.5%; specificity, 92.3%; validation group: AUC, 0.84; sensitivity, 75.0%; specificity, 92.3%). Conclusion: CEUS-KDPI accurately predicted DGF after kidney transplantation. CEUS may be a potential noninvasive tool for bedside examinations before organ procurement and may be used to predict early renal function after kidney transplants kidneys from donors after brain death.