Magnetite for phosphorus removal in low concentration phosphorus-contained water body

Xiang, Heng,Liu, Chaoxiang,Pan, Ruiling,Han, Yun,Cao, Jing Techno-Press 2014 Advances in environmental research Vol.3 No.2

Magnetite was chosen as a typical adsorbent to study its phosphate adsorption capacity in water body with low concentration of phosphorus (below $2mg\;PL^{-1}$). Magnetite was collected from Luoyang City, Henan Province, China. In this research, three factors have been studied to describe the adsorption of phosphate on magnetite, which was solution concentration (concentration ranging from 0.1 to $2.5mg\;PL^{-1}$), suspension pH (1 to 13) and temperature (ranging from $10^{\circ}C$ to $40^{\circ}C$). In addition, the modified samples had been characterized with XRD and FE-SEM image. The results show that iron ions contains in magnetite were the main factors of phosphorus removal. The behavior of phosphorus adsorption to substrates could be fitted to both Langmuir and Freundlich isothermal adsorption equations in the low concentration phosphorus water. The theoretical saturated adsorption quantity of magnetite is 0.158 mg/g. pH has great influence on the phosphorus removal of magnetite ore by adsorption. And pH of 3 can receive the best results. While temperature has little effect on it. Magnetite was greatly effective for phosphorus removal in the column experiments, which is a more practical reflection of phosphorous removal combing the adsorption isotherm model and the breakthrough curves. According to the analysis of heavy metals release, the release of heavy metals was very low, they didn't produce the secondary pollution. The mechanism of uptake phosphate is in virtue of chemisorption between phosphate and ferric ion released by magnetite oxidation. The combined investigation of the magnetite showed that it was better substrate for water body with low concentration of phosphorus.

Synthesis and Properties of Cellulose-based Superabsorbent Hydrogel by a New Crosslinker

Heng-Xiang Li,Xin Tian,Luming Zhang,Leili Wang,Li’e Jin,Qing Cao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.7

Cellulose-based superabsorbent hydrogel (SAH) has been successfully prepared by the grafting method withcellulose and sodium acrylate as well as aluminum hydroxide as a novel crosslinker. The factors influencing water absorptionsuch as the neutralization degree of acrylic acid (AA), the amount of initiator ammonium persulfate (APS) and crosslinker,and the proportion of cellulose to AA were investigated. The chemical structure and thermal behavior of the SAH wereanalyzed by fourier-transform infrared spectrometry, field-emission scanning electron microscopy, and thermal gravimetry,respectively. Results showed that the water absorbency of the SAH in distilled water and 0.9 wt% NaCl solution reached 922and 118 g/g when the mass ratio of cellulose to AA, APS to AA, Al(OH)3 to AA, and the neutralization degree of AA was39 wt%, 0.67 wt%, 0.89 %, and 76 %, respectively. Under the same condition, the hydrogel synthesized by traditionalcrosslinker N,N-methylenebisacrylamide was only 530 and 84 g/g in distilled water and 0.9 wt% NaCl solution, respectively. The mechanism of polymerization reaction was analyzed. And the cost and feasibility for the mass-producing the hydrogelwere analyzed.

Facile Fabrication of Extremely Small CoNi/C Core/Shell Nanoparticles for Efficient Microwave Absorber

Xiang Wen,Lizhen Hou,Lianwen Deng,Daitao Kuang,Heng Luo,Shiliang Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

CoNi magnetic nanoparticles (NPs) and hybrid architectures have attracted tremendous attention from numerous applications. In this study, a facile approach based on one-step metal-organic chemical vapor deposition (MOCVD) was developed to fabricate CoNi/C core/shell NPs with an extremely small core size of ~3.7 nm and an ultrathin shell thickness of 1–3 nm. Only 10 wt.% CoNi/C core/shell NP-filled composites with thickness of 1.6 mm exhibit an optimal reflection loss value of -25.7 dB and an absorbing bandwidth value up to 6.2 GHz. The extremely small core/shell NPs are demonstrated to have enhanced electromagnetic parameters (i.e., complex permittivity and permeability), reflection loss and broadened effective absorption bandwidth, as compared to the relatively larger NPs. The superior microwave absorbing performance should be attributed to the increased specific area with enriched interfacial polarization. The as-synthesized extremely small CoNi/C core/shell NPs are expected to be a fascinating candidate for efficient microwave absorption material with lightweight and thin thickness.

Seamless Transfer of Single-Phase Utility Interactive Inverters with a Synchronized Output Regulation Strategy

Xiang, Ji,Ji, Feifan,Nian, Heng,Zhang, Junming,Deng, Hongqiao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This study presents a strategy using the synchronized output regulation method (SOR) for controlling inverters operating in stand-alone and grid-connected modes. From the view point of networked dynamic systems, SOR involves nodes with outputs that are synchronized but also display a desirable wave shape. Under the SOR strategy, the inverter and grid are treated as two nodes that comprise a simple network. These two nodes work independently under the stand-alone mode. An intermediate mode, here is named the synchronization mode, is emphasized because the transition from the stand-alone mode to the grid-connected mode can be dealt as a standard SOR problem. In the grid-connected mode, the inverter operates in an independent way, in which the voltage reference changes for generalized synchronization where its output current satisfies the required power injection. Such a relatively independent design leads to a seamless transfer between operation modes. The closed-loop system is analyzed in the state space on the basis of the output regulation theory, which improves the robustness of the design. Simulations and experiments are performed to verify the proposed control strategy.

Seamless Transfer of Single-Phase Utility Interactive Inverters with a Synchronized Output Regulation Strategy

Ji Xiang,Feifan Ji,Heng Nian,Junming Zhang,Hongqiao Deng 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This study presents a strategy using the synchronized output regulation method (SOR) for controlling inverters operating in stand-alone and grid-connected modes. From the view point of networked dynamic systems, SOR involves nodes with outputs that are synchronized but also display a desirable wave shape. Under the SOR strategy, the inverter and grid are treated as two nodes that comprise a simple network. These two nodes work independently under the stand-alone mode. An intermediate mode, here is named the synchronization mode, is emphasized because the transition from the stand-alone mode to the grid-connected mode can be dealt as a standard SOR problem. In the grid-connected mode, the inverter operates in an independent way, in which the voltage reference changes for generalized synchronization where its output current satisfies the required power injection. Such a relatively independent design leads to a seamless transfer between operation modes. The closed-loop system is analyzed in the state space on the basis of the output regulation theory, which improves the robustness of the design. Simulations and experiments are performed to verify the proposed control strategy.

Relation between the local structure and solid solubility of the layered material LiMO2 (M=Co, Ni, Fe) in Li2MnO3

Chen Hou,Xiang Xiao,Yi-Ran Xing,Le-Le Yu,Yong-Heng Si,Han Lu,Yu-Juan Zhao 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.1

Although low solid solubility and activity of LiFeO2in xLi2MnO3·(1–x)LiFeO2 limit its practical application, it still has thepotential to become a new-generation cathode material without cobalt or nickel for Li-ion batteries. In order to understand theeffects of the local structures of different LiMO2(M = Co, Ni, Fe) layered materials on their solid solubility in Li2MnO3,partialdensities of states are calculated to determine the Jahn–Teller distortion in the layered cathode material, and the first-principlescalculation method based on density functional theory is used to optimize and compare the local structures of LiCoO2,LiNiO2,LiFeO2,LiMnO2,and Li2MnO3. The degrees of distortion of the transition metal–oxygen (M–O) and lithium–oxygen (Li–O)octahedra in the crystal structure of the material are evaluated. It is clear that the solid solubility of layered materials is relatedto the bond lengths and degrees of distortion of the M–O and Li–O octahedra. Among them, the similar bond length of LiNiO2and Li2MnO3and the high distortion of NiO6enhance the solid solubility of LiNiO2in Li2MnO3. Owing to the absence ofJahn–Teller distortion in LiFeO2and LiCoO2,the FeO6and CoO6octahedra are slightly distorted, thereby decreasing thesolid solubility of LiMO2(M = Fe, Co) in Li2MnO3. Understanding the relation between intra-octahedral distortion and solidsolubility provides simple and efficient evidence for comparing the solid solubilities of different LiMO2layered materials inthe Li2MnO3of Li-rich cathode materials. This study can be used as a reference for component design in Li-rich materials.

Genome editing in potato plants by agrobacterium-mediated transient expression of transcription activator-like effector nucleases

Jin Ma,Heng Xiang,Danielle J. Donnelly,Fan-Rui Meng,Huimin Xu,Dion Durnford,Xiu-Qing Li 한국식물생명공학회 2017 Plant biotechnology reports Vol.11 No.5

Genome editing (also known as targeted mutation) has promise for molecular breeding. Compared with the CRISPR/Cas9 system, the transcription activator-like effector nucleases (TALENs) have likely a lesser off-target rate in genome editing. Both a rapid test system for the functionality of designed TALENs and an effective delivery system for introducing the TALENs to plants are critical for successful target mutation. TALENs have usually been tested in protoplasts or introduced to plants with viral vectors. However, plant regeneration from protoplast culture can generate extensive somatic variation. Viral vectors are not always available, and plants edited by these vectors usually require virus elimination. Here, we used a nonviral, Agrobacterium-mediated transient expression approach, to serve both rapid test and effective delivery of TALENs into two vegetatively propagated potato cultivars, Solanum tuberosum Russet Burbank and Shepody. Two TALENs with different molecular weights (22 and 27 aarepeat modules) were expressed to target two endogenous genes (starch branching enzyme and an acid invertase) by Agrobacterium-mediated infiltration (agroinfiltration) into leaves of potato plants. The infiltrated leaf DNA was analyzed using restriction site loss assay and subsequent DNA sequencing. Deep sequencing of these tetraploid cultivars was also conducted to determine the zygosity at the targeted chromosomal loci. TALENs, with different molecular weights, successfully agroinfiltrated and induced mutations at both targeted loci.

Four new compounds from the bulbs of Lycoris aurea with neuroprotective effects against CoCl2 and H2O2-induced SH-SY5Y cell injuries

An Jin,Xuelian Xiang,Yun-Yun Zhu,Heng-Yi Yu,Hui-Fang Pi,Peng Zhang,Han-Li Ruan 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.3

Three new alkaloids, 2a-hydroxy-6-O-n-butyloduline,O-n-butyllycorenine, (-)-N-(chloromethyl)lycoramine(1–3), and a new phenolic compound, ((7S)-7-(4-hydroxyphenyl)-7-hydroxypropyl)-20-methylbenzene-30,60-diol (14), along with ten known alkaloids (4–13), wereisolated from the bulbs of Lycoris aurea collected fromHuaihua County of Hunan Province, China. Their structureswere elucidated by spectroscopic methods includingHRESIMS, UV, IR, and NMR. All the isolated compoundswere tested for their neuroprotective effects against CoCl2and H2O2-induced SH-SY5Y cell death. Compounds 1–7and 10 exhibited significant neuroprotective effects againstCoCl2-induced SH-SY5Y cell injury, while compounds1–5, 7, 10 and 12 showed obvious neuroprotective effectsagainst H2O2-induced SH-SY5Y cell death.

Aberrant DNA Methylation and Epigenetic Inactivation of hMSH2 Decrease Overall Survival of Acute Lymphoblastic Leukemia Patients via Modulating Cell Cycle and Apoptosis

Wang, Cai-Xia,Wang, Xiang,Liu, Hai-Bai,Zhou, Zhi-Heng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Objective: Altered regulation of many transcription factors has been shown to play important roles in the development of leukemia. hMSH2 can modulate the activity of some important transcription factors and is known to be a regulator of hematopoietic differentiation. Herein, we investigated epigenetic regulation of hMSH2 and its influence on cell growth and overall survival of acute lymphoblastic leukemia (ALL) patients. Methods: hMSH2 promoter methylation status was assessed by COBRA and pyrosequencing in 60 ALL patients and 30 healthy volunteers. mRNA and protein expression levels of hMSH2, PCNA, CyclinD1, Bcl-2 and Bax were determined by real time PCR and Western blotting, respectively. The influence of hMSH2 on cell proliferation and survival was assessed in transient and stable expression systems. Results: mRNA and protein expression of hMSH2 and Bcl-2 was decreased, and that of PCNA, CyclinD1 and Bax was increased in ALL patients as compared to healthy volunteers (P<0.05). hMSH2 was inactivated in ALL patients through promoter hypermethylation. Furthermore, hMSH2 hypermethylation was found in relapsed ALL patients (85.7% of all cases). The median survival of patients with hMSH2 methylation was shorter than that of patients without hMSH2 methylation (log-rank test, P=0.0035). Over-expression of hMSH2 in cell lines resulted in a significant reduction in growth and induction of apoptosis. Conclusions: This study suggests that aberrant DNA methylation and epigenetic inactivation of hMSH2 play an important role in the development of ALL through altering cell growth and survival.

Targeted Efficacy of Dihydroartemisinin for Translationally Controlled Protein Expression in a Lung Cancer Model

Liu, Lian-Ke,Wu, Heng-Fang,Guo, Zhi-Rui,Chen, Xiang-Jian,Yang, Di,Shu, Yong-Qian,Zhang, Ji-Nan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Objective: Lung cancer is one of the malignant tumors with greatest morbidity and mortality around the world. The keys to targeted therapy are discovery of lung cancer biomarkers to facilitate improvement of survival and quality of life for the patients with lung cancer. Translationally controlled tumor protein (TCTP) is one of the most overexpressed proteins in human lung cancer cells by comparison to the normal cells, suggesting that it might be a good biomarker for lung cancer. Materials and Methods: In the present study, the targeted efficacy of dihydroartemisinin (DHA) on TCTP expression in the A549 lung cancer cell model was explored. Results and Conclusions: DHA could inhibit A549 lung cancer cell proliferation, and simultaneously up-regulate the expression of TCTP mRNA, but down-regulate its protein expression in A549 cells. In addition, it promoted TCTP protein secretion. Therefore, TCTP might be used as a potential biomarker and therapeutic target for non-small cell lung cancers.