Reduced graphene oxide/polypyrrole composite: an advanced electrode for high-performance symmetric/asymmetric supercapacitor

Liu Guijing,Shi Yanying,Wang Lei,Song Yadong,Gao Shanmin,Liu Dong,Fan Leqing 한국탄소학회 2020 Carbon Letters Vol.30 No.4

Polypyrrole (PPy) decorated on reduced graphene oxide (rGO) flms is successfully prepared with pyrrole (Py) monomers and rGO through one-step combining oxidation with polymerization reaction. Compared with the pure individual compo�nents, rGO/PPy compound turns out better electrochemical characteristics owing to the introduction of rGO sheets, which improves the specifc surface area and the conductivity of composite material. When the amount of rGO is 10% of the total, the rGO/PPy compound delivers the best capacitance of 389.3 F g−1 at 1.0 A g−1 in a three-electrode system and 266.8 F g−1 at 0.25 A g−1 in the symmetric supercapacitor system. In addition, asymmetric device (rGO/PPy//AC) has been success�fully fabricated using optimized rGO/PPy compound as positive electrode, activated carbon as negative electrode (AC) and 1 M Na2SO4 aqueous solution as electrolyte. The device obtains long cycle stability under the high-voltage region from 0 to 1.6 V, meanwhile displaying the satisfed energy density of 19.7 Wh kg−1 at 478.1 W kg−1. Besides, the rGO/PPy//AC device presents satisfactory rate capability and long life time.

WEAK NORMAL PROPERTIES OF PARTIAL ISOMETRIES

Liu, Ting,Men, Yanying,Zhu, Sen Korean Mathematical Society 2019 대한수학회지 Vol.56 No.6

This paper describes when a partial isometry satisfies several weak normal properties. Topics treated include quasi-normality, subnormality, hyponormality, p-hyponormality (p > 0), w-hyponormality, paranormality, normaloidity, spectraloidity, the von Neumann property and Weyl's theorem.

The new focus of energy storage: flexible wearable supercapacitors

Yani Yan,Yi Zhou,Yongfeng Li,Yanzhen Liu 한국탄소학회 2023 Carbon Letters Vol.33 No.6

As the demand for flexible wearable electronic devices increases, the development of light, thin and flexible high-performance energy-storage devices to power them is a research priority. This review highlights the latest research advances in flexible wearable supercapacitors, covering functional classifications such as stretchability, permeability, self-healing and shapememory capabilities, as well as practical studies on energy harvesting capabilities.

Adsorption differences and mechanism of chitooligosaccharides with specific degree of polymerization on macroporous resins with different functional groups

Yanying Hou,Lujie Liu,Xingxing Zhang,Yuechao Zhu,Yongjun Qiu,Liming Zhao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

Ion exchange resins are promising materials for separating chitooligosaccharides (COSs) with differentdegrees of polymerization (DP). The adsorbent functional groups significantly determine the interactionswith COSs and affect their adsorption and separation efficiency. This study investigated the adsorptionbehaviors of COSs on macroporous cation exchange resins with different functional groups to clarifythe functional group effect on the adsorption of COSs with different DP, which can also help to providea theoretical basis for the selection of separation medium and optimization of the separation technicsof COSs. The results showed that the adsorption of COSs on sulfonic-acid type resin DX-10 andcarboxylic-acid type resin DC-10 were favorable, and the adsorption isotherms were in accord withthe Sips model. Adsorption thermodynamics showed that temperature had opposite effects on the tworesins’ equilibrium adsorption capacity of COSs. The diffusion coefficient of COSs on DX-10 resin wasgreater, and the affinity gap between COSs on DX-10 resin was larger than that of DC-10 resin, whichis beneficial for improving the separation resolution of COSs. In contrast, the interaction energy betweenCOSs with high DP and DC-10 resin was weaker compared with DX-10, which made the elution of COSswith high DP easier.

Weak normal properties of partial isometries

Ting Liu,Yanying Men,Sen Zhu 대한수학회 2019 대한수학회지 Vol.56 No.6

This paper describes when a partial isometry satisfies several weak normal properties. Topics treated include quasi-normality, subnormality, hyponormality, $p$-hyponormality ($p>0)$, $w$-hyponormality, paranormality, normaloidity, spectraloidity, the von Neumann property and Weyl's theorem.

Analysis of the effect of Rhodopseudomonas palustris on the lead exposure rat model using 1H-NMR-based metabolomics of urine and plasma

Chai Shutong,Zheng Ziyun,Liu Yani,Liang Yanhui,Yang Hong,Chen Jie,Bai Hongjuan,Yang Guan-e 대한독성 유전단백체 학회 2023 Molecular & cellular toxicology Vol.19 No.2

Background Rhodopseudomonas palustris had the eff ect of adsorbing and removing lead ions. Metabolomics is a comprehensive analysis based on several metabolites or biomarkers. Objective The paper aimed to investigate the restorative eff ect and the potential mechanisms of R. palustris in rats with the lead exposure model using 1 H-NMR metabolomics. Results Nine endogenous metabolites from rat plasma and 13 endogenous metabolites from rat urine were identifi ed as potential biomarkers of the symptoms of lead poisoning. The changes of metabolites levels in the plasma included lower levels of valine, acetoacetate, and N-acetyl-glycoprotein and a higher concentration of lactate, acetate, creatine, threonine, glutamine, and asparagine in model group compared with control group. Furthermore, increased citrate, succinate, dimethylamine, pyruvate, acetoacetate, α -oxoglutarate and asparagine, accompanied by decreased LDL/VLDL, taurine, creatinine, glucose and hippurate levels were observed in the model group compared with the control group in the urine. Biochemical parameters and histopathology examination dovetailed well with the metabolomics data. Treatment with R. palustris at a certain degree returned the levels of these metabolites to normal levels. Plasma and urine metabolomic analysis showed changes associated with energy metabolism, amino acids and fatty acid metabolism of lead exposure rats. Conclusion The eff ects of removing lead ions of R. palustris in rats with lead exposure were confi rmed. This research demonstrated that 1 H-NMR-based metabolomics was a promising tool to identify potential biomarkers and unravel protective eff ect mechanisms of R. palustris in lead poisoning rats.

Synergic adsorption of acid blue 80 and heavy metal ions (Cu2+/Ni2+) onto activated carbon and its mechanisms

Xinsheng Luo,Ziqiang Lei,Pengxin Zhou,Yani Liu,Guofu Maa,Zhe Zhang 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.27 No.-

A novel synergic adsorption process of acid blue 80 dye (AB80) and heavy metal ions (Cu2+ or Ni2+) on alow-cost activated carbon (PRAC) which was prepared from potato residue was reported. The resultsindicated that the maximum adsorption capacity of PRAC for AB80 and Cu2+ were 294.7 mg/g and45.0 mg/g in the AB80-Cu2+ system, respectively. In the mono-component system, the values were173.0 mg/g and 26.8 mg/g, respectively. Compared with mono-component system, the AB80 and Cu2+showed good synergistic effect on PRAC. The similarly result was revealed in the AB80-Ni2+ system. For abinary system, the adsorption isotherm of AB80 and heavy metal ions followed the non-modified Sipsmodel, and the adsorption kinetic models followed the pseudo-second order kinetic model. The effect ofpH also was discussed, and showed significant role in the binary-component system adsorption. Theselectivity in synergic adsorption was discussed. BET, FE-SEM/EDX and XPS were used to characterizePRAC with and without adsorbed dye and heavy metal ions, possible mechanisms of AB80 and heavymetal ions synergic adsorption process were proposed.

Thioredoxin A of Streptococcus suis Serotype 2 Contributes to Virulence by Inhibiting the Expression of Pentraxin 3 to Promote Survival Within Macrophages

Zhao Chijun,Jia Xinglin,Pan Yanying,Liao Simeng,Zhang Shuo,Ji Chunxiao,Kuang Guangwei,Wu Xin,Liu Quan,Tang Yulong,Fang Lihua 한국미생물학회 2023 The journal of microbiology Vol.61 No.4

Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen that can infect humans in contact with infected pigs or their byproducts. It can employ different types of genes to defend against oxidative stress and ensure its survival. The thioredoxin (Trx) system is a key antioxidant system that contributes adversity adaptation and pathogenicity. SS2 has been shown to encode putative thioredoxin genes, but the biological roles, coding sequence, and underlying mechanisms remains uncharacterized. Here, we demonstrated that SSU05_0237-ORF, from a clinical SS2 strain, ZJ081101, encodes a protein of 104 amino acids with a canonical CGPC active motif and an identity 70–85% similar to the thioredoxin A (TrxA) in other microorganisms. Recombinant TrxA efficiently catalyzed the thiol-disulfide oxidoreduction of insulin. The deletion of TrxA led to a significantly slow growth and markedly compromised tolerance of the pathogen to temperature stress, as well as impaired adhesion ability to pig intestinal epithelial cells (IPEC-J2). However, it was not involved in H2O2 and paraquat-induced oxidative stress. Compared with the wild-type strain, the ΔTrxA strain was more susceptible to killing by macrophages through increasing NO production. Treatment with TrxA mutant strain also significantly attenuated cytotoxic effects on RAW 264.7 cells by inhibiting inflammatory response and apoptosis. Knockdown of pentraxin 3 in RAW 264.7 cells was more vulnerable to phagocytic activity, and TrxA promoted SS2 survival in phagocytic cells depending on pentraxin 3 activity compared with the wild-type strain. Moreover, a co-inoculation experiment in mice revealed that TrxA mutant strain is far more easily cleared from the body than the wild type strain in the period from 8–24 h, and exhibits significantly attenuated oxidative stress and liver injury. In summary, we reveal the important role of TrxA in the pathogenesis of SS2.