A Novel Approach to Synthesize Nitrogen-Deficient g-C3N4 for the Enhanced Photocatalytic Contaminant Degradation and Electrocatalytic Hydrogen Evolution

Xiaoxiao Li,Kailian Zhang,Man Zhou,Kai Yang,Shi Yang,Xiaoshuai Ma,Changlin Yu,Yu Xie,Weiya Huang,Qizhe Fan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.02

Graphitic carbon nitride with nitrogen vacancies was successfully synthesized by the three-step method for the calcination of melamine, following urea-assisted hydrothermal and jacjoin calcination approach. The structural, surface, optical and electric properties were characterized by XRD, FT-IR, SEM, TEM, UV–Vis DRS, PL, N2 physical adsorption/desorption and electrochemical methods, which proved that this strategy of modifying g-C3N4 by nitrogen vacancies not only increased the specific surface area, exposed more active sites, but also inhibited the recombination of photogenerated carriers on the surface of photocatalysts, resulting in the enhancement of photocatalytic and electrocatalytic performances. The photocatalytic activities were measured under visible light irradiation ( λ > 420 nm), and their degradation efficiencies could be achieved for 99.8%, 55%, 100% and 99.7% corresponding to that of rhodamine B, acid orange II, methyl orange and methylene blue, respectively. The trapping experiments demonstrated that ·O2- played an important role in the degradation process. In addition, being an active electrocatalyst, nitrogen-deficient g-C3N4 showed a lower Tafel slope, smaller overpotential and the more effective electrochemical surface area compared with that of bare g-C3N4 in neutral media. This work underlines the importance of defect engineering to promote catalytic performance, which can provide a simple and efficient way for modifying g-C3N4 and other N-based catalysts.

Clinical and Immunological Factors Associated with Postpartum Hepatic Flares in Immune-Tolerant Pregnant Women with Hepatitis B Virus Infection Treated with Telbivudine

( Junfeng Lu ),( Xiaoxiao Wang ),( Yunxia Zhu ),( Lina Ma ),( Sujun Zheng ),( Zhongjie Hu ),( Xinyue Chen ) 대한간학회 2021 Gut and Liver Vol.15 No.6

Background/Aims: To investigate postpartum hepatic flares and associated factors in highly viremic pregnant patients in the immune tolerance phase who adopted telbivudine (LdT) treatment in the last trimester to reduce vertical transmission of hepatitis B virus. Methods: Hepatitis B e antigen (HBeAg)-positive, highly viremic pregnant women were recruited for this prospective study. Treatment with LdT was started from 28 weeks of gestation. Virological and biochemical markers were examined before LdT treatment, antepartum and postpartum. Serial blood samples at the same time were collected to detect cytokines and cortisol (COR). Results: Fifty-six of 153 patients (36.6%) had postpartum hepatic flares, defined as a 2-fold increase in alanine aminotransferase 6 weeks after delivery. Age and the antepartum alanine aminotransferase and postpartum HBeAg levels were independent influencing factors of postpartum hepatic flares. Cytokines showed no regularity during or after pregnancy. Compared with the patients with no postpartum flares, the patients with flares had lower baseline interferon γ and COR levels (p=0.022 and p=0.028) and higher postpartum interferon γ levels (p=0.026). Conclusions: A high proportion of highly viremic and immune-tolerant pregnant patients treated with LdT in the last trimester had postpartum hepatic flares, which implied that these patients entered the immune clearance phase after delivery. Thus, this may create an appropriate opportunity for re-antiviral therapy. (Gut Liver 2021;15:887-894)

Preparation and electrochemical capacitive properties of C–MnO2 composite with foam‑like structure based on modified rubber

Peng Li,Xiaoxiao Ma,Yurong Liang,Junhua Tan,Liyong Wang 한국탄소학회 2019 Carbon Letters Vol.29 No.6

Nanoporous carbon/MnO2 (C–MnO2) composites with foam-like structure based on modified nitrile butadiene rubber were achieved by thermal treatment, followed by alkaline solution etching and dipping method. The XRD, nitrogen adsorption and desorption, and SEM and TEM were used to characterize the microstructure of the obtained C–SiO2, C and C–MnO2. Finally, all the obtained samples have been used in three-electrode system to study the electrochemical properties including cyclic voltammetry, galvanostatic charge/discharge and AC impedance for supercapacitor. The study found that the specific capacity of C–MnO2 electrode material for supercapacitor could reach as high as 109 F/g under the current density of 0.5 A/g, which is much higher than those of the other two. These superior electrochemical properties are attributed to the synergistic effect MnO2 particles with the C matrix which functions as a conductive support.

Facile Fabrication of MCo2S4(M = Mn, Ni) Nanotube Arrays for High-Performance Supercapacitors

Peng Li,Xiaoxiao Ma,Fei Liu,Junhua Tan,Yanliang Zhao,Liyong Wang,Kaijin Zhu 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.4

MCo2S4(M = Mn, Ni) nanomaterials are attracting considerable attention because of their unique nanostructure, good redoxproperties, excellent theoretical capacitance, low cost and easy preparation. Herein, MCo2S4(M = Mn, Ni) nanotube arrayshave been fabricated by a one-pot hydrothermal method and could be used as conductive additive and binder-free electrodesfor supercapacitors. The results show that the specific capacitance of MCo2S4(M = Mn or Ni) nanotube arrays could reachas high as 2667 and 1623 F/g at the current density of 10 A/g, respectively, indicating high rate performance. Furthermore,the MnCo2S4nanotube arrays exhibited excellent cycling stability (68% of initial specific capacitance after 1800 cycles). These excellent electrochemical properties benefit from the synergistic effects of unique tubular microstructure and highconductivity of the samples.

Preparation and electrochemical capacitive properties of C–MnO2 composite with foam-like structure based on modified rubber

Li Peng,Ma Xiaoxiao,Liang Yurong,Tan Junhua,Wang Liyong 한국탄소학회 2019 Carbon Letters Vol.29 No.6

Nanoporous carbon/MnO2 (C–MnO2) composites with foam-like structure based on modified nitrile butadiene rubber were achieved by thermal treatment, followed by alkaline solution etching and dipping method. The XRD, nitrogen adsorption and desorption, and SEM and TEM were used to characterize the microstructure of the obtained C–SiO2, C and C–MnO2. Finally, all the obtained samples have been used in three-electrode system to study the electrochemical properties including cyclic voltammetry, galvanostatic charge/discharge and AC impedance for supercapacitor. The study found that the specific capacity of C–MnO2 electrode material for supercapacitor could reach as high as 109 F/g under the current density of 0.5 A/g, which is much higher than those of the other two. These superior electrochemical properties are attributed to the synergistic effect MnO2 particles with the C matrix which functions as a conductive support.

Meta-analysis of the effect of the overexpression of aquaporin family genes on the drought stress response

Ren Jianhong,Yang Xiaoxiao,Ma Chunying,Wang Yuling,Zhao Juan,Kang Le 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.2

Aquaporin (AQP) plays an essential role in water uptake and transport in plants, especially in the response to drought stress, which suggests the use of AQP expression to regulate plant water-use efciency. The overexpression of various AQP genes in a variety of plants has been reported, but inconsistencies in the experimental variables (such as stress type, gene donor, and recipient genus) and physiological parameters used to evaluate transgenic plants have made it difcult to elucidate the complex mechanisms by which AQPs afect drought tolerance. In this study, we performed a meta-analysis to categorize the responses of physiological parameters involved in drought tolerance in AQP-overexpressing plants and to evaluate the experimental variables that afect transgenic plant performance. The results of various studies indicated that two primary physiological processes (osmotic adjustment and alleviation of oxidative damage) were signifcantly afected by AQP overexpression. Among the examined experimental variables, treatment media (soil), stress type (no watering), stress duration (long-term), recipient genus (Nicotiana), donor species (Musaceae), and gene family (PIP2) had positive impacts on drought tolerance in transgenic plants. These fndings may help to guide future studies investigating the function of AQPs in the response of plants to water defcit stress.