Study on the detection behavior of defect-rich single-walled carbon nanotubes toward perchlorate

Chen, Yi,Nguyen, Thuy Hang,Zhang, Shao Lin,Zhang, Z.,Yue, Hongyan,Jian, Jiawen,Yang, Woo-Chul World Scientific Publishing Company 2018 Functional materials letters Vol.11 No.2

<P>Defect-rich single-walled carbon nanotubes (SWCNTs) were prepared by a water vapor flow-assisted chemical vapor deposition process. The correlation between defect density and water flow was quantitively studied using Raman spectrum. The detection capabilities of defective SWCNTs films toward perchlorate anions were investigated. It was found the defect-rich SWCNTs could adsorb more perchlorate anions owing to the strong chemical bonding between anions and defective sites. However, the detective response of defective SWCNTs toward perchlorate was not in compliance with anion adsorption. A tradeoff phenomenon between response and adsorption was found as the defect density of SWCNTs increased. This work is expected to provide a guidance to the future design of SWCNTs based ion detector.</P>

Numerical Study on Interfacial Contact Characteristics between Composite Transport Media for Fuel Cell Applications

Junyu Chen,Jiawen Liu,Sukkee Um 한국신재생에너지학회 2021 AFORE Vol.2021 No.10

Resistance Behaviours of Clamped HFR-LWC Beam Using Membrane Approach

Wanxiang Chen,Jiawen Cai,Junxuan Huang,Xiaoyu Yang,Jianjun Ma 한국콘크리트학회 2024 International Journal of Concrete Structures and M Vol.18 No.3

Beam-like members sustaining the combined action of transverse load and membrane force exhibit a special load response to progressive deflection. A theoretical model is therefore developed to depict the resistance behaviours of clamped reinforced concrete (RC) beams observed in tests. The support-induced membrane effects are simulated by a longitudinal spring and a rotational spring. The load responses to progressive deflection are obtained using the membrane approach, and the prediction accuracies of proposed method are validated by a series of four-point bending tests on hybrid fibre reinforced-lightweight aggregate concrete (HFR-LWC) beam. It is illustrated that the bearing capacities of clamped HFR-LWC beam are significantly enhanced by the membrane effect. Ultimate load of the clamped beam ranges from 64.0 to 184.0 kN, and the larger bearing capacity compared with simply supported beam is obtained. An ultimate load of 1.85 to 5.31 times the yield line value is achieved, and thereby, the ultimate resistance of the clamped beam might be seriously underestimated using yield line approach. A strong support constraint is beneficial for increasing the load-carrying capacity of clamped HFR-LWC beam, although the large longitudinal restraint stiffness would inevitably gives rise to brittle failure. The relative errors between predicted load and measured value are less than 7.23%, indicating that the presented model is a promising tool to estimate the ultimate load of clamped beam-like member.

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.

Performance optimization of annealing salp swarm algorithm: frameworks and applications for engineering design

Song Jiuman,Chen Chengcheng,Heidari Ali Asghar,Liu Jiawen,Yu Helong,Chen Huiling 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.2

Swarm salp algorithm is a swarm intelligence optimization algorithm enlightened by the movement and foraging behaviors of the salp population. The salp swarm algorithm (SSA) has a simple structure and fast processing speed and can gain significant results on objective functions with fewer local optima. However, it has poor exploration ability and is easy to suffer from the local optimal solutions, so it performs poorly on multimodal objective functions. Besides, its unfair balance of exploration and exploitation is another notable shortcoming. To ameliorate these shortcomings and enhance the algorithm’s performance on multimodal functions, this research proposes simulated annealing (SA) improved salp swarm algorithm (SASSA). SASSA embeds the SA strategy into the followers’ position updating method of SSA, performs a certain number of iterations of the SA strategy, and uses Lévy flight to realize the random walk in the SA strategy. SASSA and 23 original and improved competitive algorithms are compared on 30 IEEE CEC2017 benchmark functions. SASSA ranked first in the Friedman test. Compared with SSA, SASSA can obtain better solutions on 27 benchmark functions. The balance and diversity experiment and analysis of SSA and SASSA are carried out. SASSA’s practicability is verified by solving five engineering problems and the fertilizer effect function problem. Experimental and statistical results reveal that the proposed SASSA has strong competitiveness and outperforms all the competitors. SASSA has excellent exploration ability, suitable for solving composition functions with multiple peaks. Meanwhile, SASSA brings about a good balance of exploration and exploitation and dramatically improves the quality of the solutions.

Inhibition of Fatty Acid β-Oxidation by Fatty Acid Binding Protein 4 Induces Ferroptosis in HK2 Cells Under High Glucose Conditions

Zhihua Zheng,Jiasi Chen,Keping Wu,Yan Lei,Mingcheng Huang,Lokyu Cheng,Hui Guan,Jiawen Lin,Ming Zhong,Xiaohua Wang 대한내분비학회 2023 Endocrinology and metabolism Vol.38 No.2

Background: Ferroptosis, which is caused by an iron-dependent accumulation of lipid hydroperoxides, is a type of cell death linked todiabetic kidney disease (DKD). Previous research has shown that fatty acid binding protein 4 (FABP4) is involved in the regulation of ferroptosis in diabetic retinopathy. The present study was constructed to explore the role of FABP4 in the regulation of ferroptosis in DKD. Methods: We first detected the expression of FABP4 and proteins related to ferroptosis in renal biopsies of patients with DKD. Then, we used a FABP4 inhibitor and small interfering RNA to investigate the role of FABP4 in ferroptosis induced by high glucosein human renal proximal tubular epithelial (HG-HK2) cells. Results: In kidney biopsies of DKD patients, the expression of FABP4 was elevated, whereas carnitine palmitoyltransferase-1A (CPT1A), glutathione peroxidase 4, ferritin heavy chain, and ferritin light chain showed reduced expression. In HG-HK2 cells, the induction of ferroptosis was accompanied by an increase in FABP4. Inhibition of FABP4 in HG-HK2 cells changed the redox state, suppressing the production of reactive oxygen species, ferrous iron (Fe2+), and malondialdehyde, increasing superoxide dismutase, and reversing ferroptosis-associated mitochondrial damage. The inhibition of FABP4 also increased the expression of CPT1A, reversed lipiddeposition, and restored impaired fatty acid β-oxidation. In addition, the inhibition of CPT1A could induce ferroptosis in HK2 cells. Conclusion: Our results suggest that FABP4 mediates ferroptosis in HG-HK2 cells by inhibiting fatty acid β-oxidation.

Atractylenolides (I, II, and III): a review of their pharmacology and pharmacokinetics

Mao Deng,Huijuan Chen,Jiaying Long,Jiawen Song,Long Xie,Xiaofang Li 대한약학회 2021 Archives of Pharmacal Research Vol.44 No.7

Atractylodes macrocephala Koidz is a widelyused as a traditional Chinese medicine. Atractylenolides(-I, -II, and -III) are a class of lactone compounds derivedfrom Atractylodes macrocephala Koidz . Research intoatractylenolides over the past two decades has shown thatatractylenolides have anti-cancer, anti-infl ammatory, antiplatelet,anti-osteoporosis, and antibacterial activity; protectthe nervous system; and regulate blood glucose and lipids. Because of structural diff erences, both atractylenolide-I andatractylenolide-II have remarkable anti-cancer activities,and atractylenolide-I and atractylenolide-III have remarkableanti-infl ammatory and neuroprotective activities. Wetherefore recommend further clinical research on the anticancer,anti-infl ammatory and neuroprotective eff ects ofatractylenolides, determine their therapeutic eff ects, aloneor in combination. To investigate their ability to regulateblood glucose and lipid, as well as their anti-platelet, antiosteoporosis,and antibacterial activities, both in vitro andin vivo studies are necessary. Atractylenolides are rapidlyabsorbed but slowly metabolized; thus, solubilization studiesmay not be necessary. However, due to the inhibitory eff ectsof atractylenolides on metabolic enzymes, it is necessaryto pay attention to the possible side eff ects of combiningatractylenolides with other drugs, in clinical application. Inshort, atractylenolides have considerable medicinal valueand warrant further study.

An experimental study on low-velocity nonlinear flow in vuggy carbonate reservoirs

Haitao Wu,Fujun Li,Jiawen Liu,Jiang Chen,Xiaowei Lv,Wei Hu 한국자원공학회 2016 Geosystem engineering Vol.19 No.4

Vuggy carbonate reservoirs in the Middle East, which have characteristics such as high porosity, low permeability, and few fractures, are significantly different from fractured-vuggy carbonate reservoirs. In this study, single-phase flow experiments and core mercury injection experiments were conducted to analyze the pore size distribution and low-velocity nonlinear flow characteristics of vuggy carbonate rocks in Halfaya oilfield. The results show that the relationship between pseudo-threshold pressure gradient and permeability in matrix carbonate rocks is linear. However, vuggy type does not exhibit the same linear relationship. Compared with matrix type, vuggy carbonate rock has a nonlinear flow zone when the pressure gradient is comparatively low and the nonlinear flow characteristics are quite different from those of low-permeability sandstone reservoirs. Because of the multi-polarization of flow channel radius in vuggy carbonate rocks, fluid stepwise starts flowing as the pressure gradient increases. Vuggy carbonate rock has a pseudo-threshold pressure gradient during the low-velocity flow, but the actual threshold pressure gradient does not exist. The concept of whole channel flow pressure gradient is presented in this paper. The results contribute to improve the understanding of low-velocity flow characteristics of vuggy carbonate reservoirs.

Use of Long-chain Alcohol in Extraction and Purification of Lincomycin from Fermentation Broth

Wu, Bin,Zhu, Jiawen,Chen, Kui,Ji, Lijun,Guo, Jianguo,Zhao, Jianxi 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.2

Low selectivity for lincomycin in butanol extraction process leads to relatively higher content of impurities. A novel process for extraction of lincomycin from fermentation broth was studied in this work. Mixture of n-octanol and n-decanol is used as extractant to replace n-butanol in extraction of lincomycin. Oprimal operation conditions for the process have been studied. Due to higher extraction selectivity for lincomycin A by long-chain alcohol, content of impurity(lincomycin B) in the final product is much lower than that in product by butanol process. Furthemore, the practicability for combination of long-chain alcohol and butanol in purification of linecomycin was investigated.

Experimental study and modeling of residence time distribution in impinging stream reactor with GDB model

Lijun Ji,Kui Chen,Jiawen Zhu,Bin Wu 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.4

Residence time distribution (RTD) in an impinging streams reactor with two or four nozzles was investigated with KCl solution as a tracer. The results showed that the flow pattern in the reactor was close to that in a continuous stirred tank reactor (CSTR). Macromixing process in the reactor was improved obviously when the opposite nozzles were added. Based on the analysis of flow region in the reactor, gamma distributionmodel with bypass (GDB) was applied for study on the RTD of the reactor. It was found that RTD in the impinging streams reactor could be finely described by the model. Also the effects of experimental conditions on parameters of model were analyzed according to the correlated values of the model parameters.