Evaluation and optimization of SrCo0.9Ta0.1O3−δ perovskite as cathode for solid oxide fuel cells

Qingjun Zhou,Tong Wei,Yihua Shi,Songqing Guo,Yan Li,Jingxin Su,Huan Ren,Yin Zhu,김경국 한국물리학회 2012 Current Applied Physics Vol.12 No.4

The SrCo0.9Ta0.1O3-δ (SCT) perovskite-type oxide is synthesized by the conventional solid state reaction method and examined as an alternative cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The electrical conductivity of SCT sample reaches 250e152 S cm-1 in the temperature range 600e800 ℃. SCT exhibits good chemical compatibility with the intermediate-temperature electrolyte material Sm0.2Ce0.8O1.9 (SDC). The average thermal expansion coefficient of SCT is 21.4 × 10-6 K-1. The cathode area specific resistance (ASR) of SCT is only 0.095 U cm2 at 750 ℃ and it decreases to 0.068 U cm2 when SDC is added to form a SCT-SDC composite cathode. The results indicate that the SCT can be a promising alternative cathode material for IT-SOFCs.

Seismic Performance and Failure Mechanism of a Subway Station Based on Nonlinear Finite Element Analysis

Wenting Li,Qingjun Chen 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.2

A nonlinear three-dimensional finite element model is employed to investigate the seismic performance and failure mechanism of a subway station. The interaction between subway station and surrounding soil is considered and the nonlinear behavior of the station structure is taken into account. Structural concrete and steel bars are simulated separately. The results demonstrated that the carrying capacities of structural middle columns and wall-to-roof slab connections are vital in underground structure’s seismic design. During an earthquake, the structure’s plastic damage first appears at beam-to-roof slab connections; but the damage at beam-to-roof slab connections does not develop significantly as seismic going. The heaviest damage parts is columns’ bottom, and then is columns’ top. The damage of wall-to-slab connections can, firstly, let the load transfer to columns and, secondly, reduce the restraint to the roof slab. The relative displacement between the roof slab and bottom slab leads to additional moment on structural middle columns. Besides, the damage at the connections of walls-to-diagonal bracings and slabs-to-diagonal bracings is remarkable. The structure is failure as an italic “M” shape. The results are consistent with the phenomena observed in the collapse of Daikai subway station during 1995 Great Hanshin Earthquake.

Magnolol Induces Apoptosis via Activation of Both Mitochondrial and Death Receptor Pathways in A375-S2 Cells

You Qingjun,Li Mingqiu,Jiao Guoqing 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.12

Magnolol inhibited proliferation of human malignant melanoma A375-S2 cells. The drug induced oligonucleosomal fragmentation of DNA in A375-S2 cells and increased caspase-3, 8, 9 activities followed by the degradation of caspase-3 substrates, inhibitor of caspase dependent DNase (ICAD) and poly-(ADP-ribose) polymerase (PARP). Pan-caspase inhibitor (z-VADfmk), caspase-3 inhibitor (z-DEVD-fmk), capase-8 inhibitor (z-IETD-fmk), caspase-9 inhibitor (z-LEHD-fmk) and caspase-10 inhibitor (z-AEVD-fmk) inhibited magnolol-induced A375-S2 cell apoptosis. The level of anti-apoptotic mitochondrial protein Bcl-2 was up-regulated while the level of pro-apoptotic protein Bax was down-regulated. Taken together, our results indicate that magnolol induces apoptosis by activation of both mitochondrial and death receptor pathways in A375-S2 cells.

High vis-light photocatalytic property of g-C3N4 on four pollutants (RhB, MB, TC-HCl and P-Nitrophenol)

Lian Xiaoxue,Li Yan,Zou Yunling,An Dongmin,Wang Qiong,Zhou Qingjun,Li Xueqi 한국물리학회 2022 Current Applied Physics Vol.39 No.-

The g-C3N4 nanosheets were synthesized by a multistage program calcination with different heating rate, which was an easy, low-cost, and quick method. The morphology and structure of samples were characterized by various techniques. The performance evaluation of the samples was tested by degrading Rhodamine B, Methylene Blue, Tetracycline Hydrochloride and P-Nitrophenol in visible light. The results show that the photodegradation properties of TP-g-C3N4 prepared by multistage program calcination are the best than others. In particular, the degradation rate of TP-g-C3N4 to Rhodamine B reached 99.6% in just 4 min. TP-g-C3N4 catalyst has excellent stability and recycling performance. According to free radical capture experiments, •O2- may be the main active species for pollutant degradation. The possible photocatalytic degradation mechanism was also discussed. Due to the high specific surface area and a narrow band gap, the TP-g-C3N4 becomes a promising photocatalyst.

Amentoflavone protects the hematopoietic system of mice against γ‑irradiation

Xin-yan Qu,Qingjun Li,Xiao-juan Zhang,Zhaofen Wang,Shengqi Wang,Zhe Zhou 대한약학회 2019 Archives of Pharmacal Research Vol.42 No.11

Some flavonoids have been shown to exhibitgood antioxidant activity and protect mice from damageinduced by radiation. Amentoflavone (AMF), a biflavonoidderived from the traditional herb-Selaginella tamariscina,has been reported to have antioxidant properties. The protectiveeffects and mechanism of action of AMF against radiationinjury remain unknown. In this study, male C57BL/6mice were subjected to total-body 60Co γ-irradiation at 7.5or 3.0 Gy. The survival rate and mean survival time wereevaluated to determine the radioprotective effect of AMF. Number of peripheral blood cells, frequency of colony formingunit-granulocytes, monocytes and micronuclei weremeasured to assess the protective effects of AMF on thehematopoietic system. Levels of superoxide dismutase andglutathione, and pathological changes in the bone marrowwere determined. Additionally, next-generation sequencingtechnology was used to explore potential targets of AMF. Weobserved that AMF markedly extends average survival time,reduces injury to the hematopoietic system and promotes itsrecovery. Furthermore, treatment with AMF significantlyattenuated radiation-induced oxidative stress. In addition,AMF had a significant effect on gene tumor necrosis factor alpha-induced protein 2. Together, the results of this studysuggest that AMF is a potential protective agent againstradiation injury.

Indole-3-acetic acid ameliorates dextran sulfate sodium-induced colitis via the ERK signaling pathway

Xinyan Qu,Yingying Song,Qingjun Li,Qi Xu,Yanru Li,Huimin Zhang,Xuemei Cheng,Charles R. Mackay,Quanbo Wang,Wei Liu 대한약학회 2024 Archives of Pharmacal Research Vol.47 No.3

Microbiota-derived catabolism of nutrients is closely related to ulcerative colitis (UC). The level of indole-3-acetic acid(IAA), a microbiota-dependent metabolite of tryptophan, was decreased signifi cantly in the feces of UC patients. Thus supplementationwith IAA could be a potential therapeutic method for ameliorating colitis. In this work, the protective eff ect ofsupplementation with IAA on dextran sulfate sodium (DSS)-induced colitis was evaluated, and the underlying mechanismwas elucidated. The results indicated that the administration of IAA signifi cantly relieved DSS-induced weight loss, reducedthe disease activity index (DAI), restored colon length, alleviated intestinal injury, and improved the intestinal tight junctionbarrier. Furthermore, IAA inhibited intestinal infl ammation by reducing the expression of proinfl ammatory cytokines andpromoting the production of IL-10 and TGF-β1. In addition, the ERK signaling pathway is an important mediator of variousphysiological processes including infl ammatory responses and is closely associated with the expression of IL-10. Notably,IAA treatment induced the activation of extracellular signal-regulated kinase (ERK), which is involved in the progressionof colitis, while the ERK inhibitor U0126 attenuated the benefi cial eff ects of IAA. In summary, IAA could attenuate theclinical symptoms of colitis, and the ERK signaling pathway was involved in the underlying mechanism. Supplementationwith IAA could be a potential option for preventing or ameliorating UC.

Blasting vibration velocity prediction based on least squares support vector machine with particle swarm optimization algorithm

Qing Yuan,Shihong Zhai,Li Wu,Peishuai Chen,Yuchun Zhou,Qingjun Zuo 한국자원공학회 2019 Geosystem engineering Vol.22 No.5

In blasting excavation engineering of super-large section underground caverns, blasting vibration velocity prediction accuracy is affected by many factors. In order to improve its accuracy, the key problem is to obtain these affect factors comprehensively. In this paper, we innovatively put forward eight independent factors in the aspect of explosion source conditions, engineering conditions and propagation medium conditions. These factors have complex non-linear relationship with blasting vibration velocity. We consider particle swarm optimization (PSO) algorithm and least squares support vector machine (LS-SVM) method for prediction (PSO-LSSVM). In this way, how to determine the characteristic parameters and calculation rules of PSO-LSSVM method is another key problem, which has been innovatively solved in this paper. Then it is used to predict the blasting vibration velocity of underground water-sealed LPG caverns in Yantai, China, and compared with Sadov’s formula (SA), fuzzy neural network (FNN) and LS-SVM methods. The results indicate that relative errors of PSO-LSSVM are significantly less than LS-SVM, FNN and SA. Whether global root mean square relative error for prediction accuracy, or group number meeting requirement of error threshold value for generalization performance, the PSO-LSSVM method is superior to LS-SVM, FNN and SA with best availability and superiority.

Single-cell transcriptome analysis reveals cellular heterogeneity in the ascending aortas of normal and high-fat diet-fed mice

Kan Hao,Zhang Ka,Mao Aiqin,Geng Li,Gao Mengru,Feng Lei,You Qingjun,Ma Xin 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

The aorta contains numerous cell types that contribute to vascular inflammation and thus the progression of aortic diseases. However, the heterogeneity and cellular composition of the ascending aorta in the setting of a high-fat diet (HFD) have not been fully assessed. We performed single-cell RNA sequencing on ascending aortas from mice fed a normal diet and mice fed a HFD. Unsupervised cluster analysis of the transcriptional profiles from 24,001 aortic cells identified 27 clusters representing 10 cell types: endothelial cells (ECs), fibroblasts, vascular smooth muscle cells (SMCs), immune cells (B cells, T cells, macrophages, and dendritic cells), mesothelial cells, pericytes, and neural cells. After HFD intake, subpopulations of endothelial cells with lipid transport and angiogenesis capacity and extensive expression of contractile genes were defined. In the HFD group, three major SMC subpopulations showed increased expression of extracellular matrix-degradation genes, and a synthetic SMC subcluster was proportionally increased. This increase was accompanied by upregulation of proinflammatory genes. Under HFD conditions, aortic-resident macrophage numbers were increased, and blood-derived macrophages showed the strongest expression of proinflammatory cytokines. Our study elucidates the nature and range of the cellular composition of the ascending aorta and increases understanding of the development and progression of aortic inflammatory disease.

Gallic Acid Ameliorates Cognitive Impairment Caused by Sleep Deprivation through Antioxidant Effect

Pang Xiaogang,Xu Yifan,Xie Shuoxin,Zhang Tianshu,Cong Lin,Qi Yuchen,Liu Lubing,Li Qingjun,Mo Mei,Wang Guimei,Du Xiuwei,Shen Hui,Li Yuanyuan 한국뇌신경과학회 2023 Experimental Neurobiology Vol.32 No.4

Sleep deprivation (SD) has a profound impact on the central nervous system, resulting in an array of mood disorders, including depression and anxiety. Despite this, the dynamic alterations in neuronal activity during sleep deprivation have not been extensively investigated. While some researchers propose that sleep deprivation diminishes neuronal activity, thereby leading to depression. Others argue that short-term sleep deprivation enhances neuronal activity and dendritic spine density, potentially yielding antidepressant effects. In this study, a two-photon microscope was utilized to examine the calcium transients of anterior cingulate cortex (ACC) neurons in awake SD mice in vivo at 24-hour intervals. It was observed that SD reduced the frequency and amplitude of Ca2+ transients while increasing the proportions of inactive neurons. Following the cessation of sleep deprivation, neuronal calcium transients demonstrated a gradual recovery. Moreover, whole-cell patch-clamp recordings revealed a significant decrease in the frequency of spontaneous excitatory post-synaptic current (sEPSC) after SD. The investigation also assessed several oxidative stress parameters, finding that sleep deprivation substantially elevated the level of malondialdehyde (MDA), while simultaneously decreasing the expression of Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) and activities of Superoxide dismutase (SOD) in the ACC. Importantly, the administration of gallic acid (GA) notably mitigated the decline of calcium transients in ACC neurons. GA was also shown to alleviate oxidative stress in the brain and improve cognitive impairment caused by sleep deprivation. These findings indicate that the calcium transients of ACC neurons experience a continuous decline during sleep deprivation, a process that is reversible. GA may serve as a potential candidate agent for the prevention and treatment of cognitive impairment induced by sleep deprivation.