Persistent free radicals in carbon-based materials on transformation of refractory organic contaminants (ROCs) in water: A critical review

Qin, Yaxin,Li, Guiying,Gao, Yanpeng,Zhang, Lizhi,Ok, Yong Sik,An, Taicheng Elsevier 2018 Water research Vol.137 No.-

<P><B>Abstract</B></P> <P>With the increased concentrations and kinds of refractory organic contaminants (ROCs) in aquatic environments, many previous reviews systematically summarized the applications of carbon-based materials in the adsorption and catalytic degradation of ROCs for their economically viable and environmentally friendly behavior. Interestingly, recent studies indicated that carbon-based materials in natural environment can also mediate the transformation of ROCs directly or indirectly due to their abundant persistent free radicals (PFRs). Understanding the formation mechanisms of PFRs in carbo-based materials and their interactions with ROCs is essential to develop their further applications in environment remediation. However, there is no comprehensive review so far about the direct and indirect removal of ROCs mediated by PFRs in amorphous, porous and crystalline carbon-based materials. The review aims to evaluate the formation mechanisms of PFRs in carbon-based materials synthesized through pyrolysis and hydrothermal carbonization processes. The influence of synthesis conditions (temperature and time) and carbon sources on the types as well as the concentrations of PFRs in carbon-based materials are also discussed. In particular, the effects of metals on the concentrations and types of PFRs in carbon-based materials are highlighted because they are considered as the catalysts for the formation of PFRs. The formation mechanisms of reactive species and the further transformation mechanisms of ROCs are briefly summarized, and the surface properties of carbon-based materials including surface area, types and number of functional groups, etc. are found to be the key parameters controlling their activities. However, due to diversity and complexity of carbon-based materials, the exact relationships between the activities of carbon-based materials and PFRs are still uncertain. Finally, the existing problems and current challenges for the ROCs transformation with carbon-based materials are also pointed out.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Abundant of PFRs formed in carbon-based materials during the synthesis process. </LI> <LI> The PFRs types and concentrations affected by synthesis conditions. </LI> <LI> The PFRs can activate oxidants and reductants to degrade organic contaminants. </LI> <LI> The PFRs can directly react with organic contaminants. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhanced photocatalytic mechanism of Ag₃PO₄ nano-sheets using MS₂ (M = Mo, W)/rGO hybrids as co-catalysts for 4-nitrophenol degradation in water

Zhang, Weiping,Li, Guiying,Wang, Wanjun,Qin, Yaxin,An, Taicheng,Xiao, Xinyan,Choi, Wonyong Elsevier 2018 Applied Catalysis B Vol.232 No.-

<P><B>Abstract</B></P> <P>A chemically modified Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>(M = Mo, W)/rGO composite was firstly synthesized via a liquid-exfoliation solvothermal method. The structure, morphology, optical properties and composition were characterized by X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, UV–vis diffuse reflectance spectra and X-ray photoelectron spectroscopy, respectively. The characterization results indicated that compact structure could be obtained by using this typical method due to in-situ chemical modification, which could also control the sizes of Ag<SUB>3</SUB>PO<SUB>4</SUB> nano-sheets by adding MS<SUB>2</SUB>/rGO hybrids. More importantly, the resultant Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO composite exhibited higher photocatalytic activity and stability toward the degradation of 4-nitrophenol than pure Ag<SUB>3</SUB>PO<SUB>4</SUB> under sunlight irradiation. The stable structure of Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO was closely related with Z-scheme electronic structure and electrical conductivity of MS<SUB>2</SUB>/rGO hybrids, leading to a higher consumption and transfer of photogenerated electrons. However, by controlling the amounts of MS<SUB>2</SUB>/rGO hybrids, more stable but lower photocatalytic activity composites could be obtained. Further analysis found that the holes and O<SUB>2</SUB> <SUP>−</SUP> were the main reactive species involved in the photocatalytic degradation of 4-nitrophenol. In addition, possible photocatalytic degradation pathways of 4-nitrophenol were also proposed based on the identified intermediates. The findings of this work may provide a new method to design efficient composites for photocatalytic degradation of organic pollutants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO catalyst was fabricated via a liquid-exfoliation solvothermal method. </LI> <LI> Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO has high photocatalytic activity and stability under sunlight. </LI> <LI> The stability of Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO was due to its rapid transfer of photogenerated e<SUP>−</SUP>. </LI> <LI> h<SUP>+</SUP> and O<SUB>2</SUB> <SUP>−</SUP> were the main RSs in photocatalytic degradation of 4-nitrophenol. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Three-dimensional Adaptive Sliding Mode Guidance Law for Missile with Autopilot Lag and Actuator Fault

Guiying Li,Zhigang Yu,Zhongxian Wang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.6

This paper investigates guidance scheme for missile with actuator failure and dynamics of autopilot. Firstly, considering first-order dynamics of autopilot, the guidance model with actuator failure is established. Secondly, an adaptive sliding mode fault-tolerant guidance law is designed on the basis of passive fault-tolerant technique and a novel nonsingular fast terminal sliding mode (NFTSM) manifold. Then, the adaptive algorithm with the feature of low-pass filter is proposed to ensure that adaptive parameters are bounded when the sliding mode is non-ideal. Finally, Lyapunov stability theory is adopted to prove that the states of closed-loop system are practical finite-time stability. Simulation results demonstrate the effectiveness and robustness of the proposed guidance strategy under the certain actuator failure.

Cyclooxygenase‐2 prevents fas‐induced liver injury through up‐regulation of epidermal growth factor receptor

Li, Guiying,Han, Chang,Xu, Lihong,Lim, Kyu,Isse, Kumiko,Wu, Tong Wiley Subscription Services, Inc., A Wiley Company 2009 Hepatology Vol.50 No.3

<P><B>Abstract</B></P><P>Cyclooxygenase‐2 (COX‐2)–derived prostaglandins participate in a number of pathophysiological responses such as inflammation, carcinogenesis, and modulation of cell growth and survival. This study used complementary approaches of COX‐2 transgenic (Tg) and knockout (KO) mouse models to evaluate the mechanism of COX‐2 in Fas‐induced hepatocyte apoptosis and liver failure <I>in vivo</I>. We generated Tg mice with targeted expression of COX‐2 in the liver by using the albumin promoter‐enhancer–driven vector. The COX‐2 Tg, COX‐2 KO, and wild‐type mice were treated with the anti‐Fas antibody Jo2 (0.5 μg/g of body weight) for 4 to 6 hours, and the extent of liver injury was assessed by histopathology, serum aminotransferases, TUNEL staining, and caspase activation. The COX‐2 Tg mice showed resistance to Fas‐induced liver injury in comparison with the wild‐type mice; this was reflected by the lower alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, less liver damage, and less hepatocyte apoptosis (<I>P</I> < 0.01). In contrast, the COX‐2 KO mice showed significantly higher serum ALT and AST levels, more prominent hepatocyte apoptosis, and higher levels of caspase‐8, caspase‐9, and caspase‐3 activity than the wild‐type mice (<I>P</I> < 0.01). The COX‐2 Tg livers expressed higher levels of epidermal growth factor receptor (EGFR) than the wild‐type controls; the COX‐2 KO livers expressed the lowest levels of EGFR. Pretreatment with a COX‐2 inhibitor (NS‐398) or an EGFR inhibitor (AG1478) exacerbated Jo2‐mediated liver injury and hepatocyte apoptosis. <I>Conclusion:</I> These findings demonstrate that COX‐2 prevents Fas‐induced hepatocyte apoptosis and liver failure at least in part through up‐regulation of EGFR. (H<SMALL>EPATOLOGY</SMALL> 2009.)</P>

Synthesis of Thermo-Sensitive Polyelectrolyte Complex Nanoparticles from CS-g-PNIPAM and SA-g-PNIPAM for Controlled Drug Release

Minyi Qi,Guiying Li,Nana Yu,Yanfeng Meng,Xunyong Liu 한국고분자학회 2014 Macromolecular Research Vol.22 No.9

In this paper, thermo-sensitive polyelectrolyte complex nanoparticles assembled from chitosan-graftpoly(N-isopropylacrylamide) (CS-g-PNIPAM) and sodium alginate-graft-poly(N-isopropylacrylamide) (SA-g-PNIPAM)were prepared for entrapment and release of 5-fluorouracil (5-FU). The morphology and size of the nanoparticles wereobserved by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The polyelectrolyte complexnanoparticles showed a narrow size distribution. The hydrogen bonding interactions between nanoparticles and5-FU, which was determined by fourier-transformed infrared spectroscopy (FTIR), increased drug loading. Glutaraldehyde,as a cross-linking agent, reinforced the nanoparticle structure and decreased the burst drug release. Whenchanging temperature, pH, or ionic strength, a sustained and controlled drug release was observed. The novel complexnanoparticles with environmentally sensitive properties are expected to be useful in the field of intelligent drugdelivery system.

Interference of periostin attenuates pathological changes, proinflammatory markers and renal fibrosis in diabetic kidney injury

Duan Xiaoting,Chen Cheng,Liu Xiaoli,Wang Taoxia,Feng Shuning,Li Jianwei,Li Guiying 한국유전학회 2023 Genes & Genomics Vol.45 No.11

Background Diabetic nephropathy (DN) is a prevalent complication of diabetes, in which inflammation and fibrosis are the significant pathogenesis. Periostin is a matricellular protein that functions on stabilizing the extracellular matrix by binding to integrins during development. This study aimed to explored the role of periostin in DN. Methods The animal and cell models of DN were constructed in streptozocin (STZ)-induced mice and high glucose-challenged human mesangial cells (HMCs). The role of periostin in pathological changes, inflammation and fibrosis in DN was investigated through biochemical detection, HE and Masson staining and scores, western blot, enzyme‑linked immunosorbent assay (ELISA) and real-time quantitative PCR (RT-qPCR) assays. Results Knockdown of periostin counteracted the STZ-induced the ratio of kidney weight and body weight, and the concentrations of urine albumin excretion (UAE), serum creatinine (Scr), urine albumin/creatinine ratio (UACR) and blood urea nitrogen (BUN) in mice. Moreover, silencing of periostin alleviated the pathological manifestations and reduced the concentrations of IL-6, TNF-α and IL-1β in mice kidney tissues and sera. Also, downregulation of periostin decreased the relative protein expression of fibronectin, collagen IV and α-SMA in kidney tissues. Meanwhile, interference of periostin attenuated the levels of pro-inflammation factors and the expressions of fibrosis markers in HG-induced HMCs. Conclusion Interference of periostin resisted DN via attenuating the pro-inflammatory cytokines release and renal fibrosis in diabetic kidney injury. Our study establishes a basis for its further study and underlying application in clinical practice in diagnosing and treating diabetic kidney injury or other relevant diseases.

Separation of Macrophages Using a Dielectrophoresis-Based Microfluidic Device

Ying Zhang,Shangyu Wang,Jie Chen,Fang Yang,Guiying Li 한국바이오칩학회 2020 BioChip Journal Vol.14 No.2

Macrophages are an important component of the immune system and play a key role in tissue damage repair and immune defense. As a potential biomarker, macrophages contribute to the early diagnosis and therapy of cancer and other disease. The isolation of macrophages is a key step in relevant research and clinical applications. However, conventional macrophage separation and purification methods rely on benchtop equipment and are time-consuming, inefficient, complicated, and immobile. Herein, we present a method based on dielectrophoresis (DEP) to rapidly separate and purify macrophages from micro-volume samples using a microfluidic device for liquid biopsy and point-of-care testing (POCT). The device can be mechanically manipulated easily for straightforward separation. The DEP force on macrophages was measured under different electric field conditions, then the macrophages were successfully separated from the mixture of macrophages (RAW264.7) and breast cancer cells (MCF-7) using the microfluidic chip. The purity of macrophages in the collections reached higher than 99%. The effects of flow rate and voltage on the separation efficiency of macrophages by DEP were further studied to optimize the separation conditions. This work proposes a new method for rapid separation of macrophages based on microfluidic systems, providing a technical foundation for macrophage-based disease monitoring and real-time rapid diagnosis.