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Zhan Y, Yin H, Feng JW, Feng AR, Hu YY, Zhang L, Zheng LG. [Molecular Signatures of Dissolved Organic Matter in the Paihe River and Its Tributaries]. Huan Jing Ke Xue 2022; 43:1365-1374. [PMID: 35258200 DOI: 10.13227/j.hjkx.202108180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Dissolved organic matter (DOM) is an abundant and critical component of aquatic ecosystems, participating in many physicochemical and biogeochemical processes. The Paihe River is the only inflow river in the Jianghuai section of "Yangtze-Huaihe water diversion" clear water gallery project; however, its DOM molecular composition information and characteristics are still unclear. In this study, the molecular characterization of DOM in the Paihe River and Guangming Dayan River was determined using Orbitrap mass spectrometry. The Pearson's correlation and principal component analysis (PCA) were used to study the relationship between molecular composition information, characteristics, and sources of DOM in two rivers. The results showed that the molecular weight and oxygen content of DOM molecules in the Paihe River were relatively low; the molecular weight, aromaticity, and unsaturation of DOM molecules in the Guangming Dayan River were relatively high. From the element composition and compound composition of the two rivers' DOM, both rivers were mainly composed of CHO-compounds, lignin, and tannins derived from land plants, which indicates that both rivers were severely affected by terrestrial input. There were high percentages of CHOS, protein, and lipid compounds of DOM in the Paihe River. According to the results of the Pearson's correlation and PCA analyses, the DOM molecules of the Paihe River were also influenced by wastewater from sewage treatment plants, urbanization processes, and microbial activity. Molecular composition information and characteristics of DOM can provide a detailed reference to improve the theoretical support for the Paihe River clear water gallery project.
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Affiliation(s)
- Ya Zhan
- Anhui Province Engineering Laboratory for Mine Ecological Remediation, School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Hao Yin
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Jing-Wei Feng
- Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China
| | - Ai-Rong Feng
- Instruments'Center for Physics and Science, University of Science and Technology of China, Hefei 230026, China
| | - Yan-Yun Hu
- Instruments'Center for Physics and Science, University of Science and Technology of China, Hefei 230026, China
| | - Liu Zhang
- Anhui Research Academy for Environmental Science, Hefei 230071, China
| | - Liu-Gen Zheng
- Anhui Province Engineering Laboratory for Mine Ecological Remediation, School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
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Zhang AY, Xu S, Feng JW, Zhao PC, Liang H. Superior degradation of phenolic contaminants in different water matrices via non-radical Fenton-like mechanism mediated by surface-disordered WO 3. Environ Sci Pollut Res Int 2022; 29:18259-18270. [PMID: 34689273 DOI: 10.1007/s11356-021-17088-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Heterogeneous Fenton-like catalysis mediated by solid catalyst is a promising oxidation technology for water purification. The redox reactivity, cost-effectiveness, and environmental compatibility of solid catalyst play governing roles in oxidant activation, radical generation, and pollutant degradation. Herein, the surface-disordered WO3 (D-WO3) functionally engineered by the unique crystalline-amorphous core-shell structure is proven to be a superior solid catalyst of heterogeneous Fenton-like catalysis for peroxymonosulfate (PMS) activation and pollutant degradation in various water matrices. Six typical phenolic and dye pollutants are effectively and selectively degraded in the D-WO3/PMS system with much reduced matrix effects. Both radical identifying and scavenging tests elucidate the important role of non-radical 1O2 and mediated electron transfer during PMS activation on the D-WO3 surface. The superior Fenton-like activity of D-WO3 can be mainly attributed to the surface and sub-surface distorted lattice sites with finely tailored atomic and electronic structures and surface chemistry. These distorted lattice sites can thermodynamically serve as the key reactive centers of dissociative adsorption and catalytic activation for both PMS and pollutant, with high adsorption energy, strong structural activation, and smooth electron transfer. Our findings provide a new chance for heterogeneous Fenton-like catalysis mediated by transition metal oxides with high capacity, low cost, and no toxicity for promising water purification.
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Affiliation(s)
- Ai-Yong Zhang
- Anhui Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China.
| | - Shuo Xu
- Anhui Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Jing-Wei Feng
- Anhui Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Pin-Cheng Zhao
- Anhui Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Heng Liang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
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Zhang AY, Zhao PC, He YY, Zhou Y, Feng JW. Non-radical activation of H 2O 2 by surface-disordered WO 3 for efficient and selective pollutant degradation with weak matrix effects. Environ Sci Pollut Res Int 2020; 27:1898-1911. [PMID: 31760621 DOI: 10.1007/s11356-019-06899-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/28/2019] [Indexed: 06/10/2023]
Abstract
Heterogeneous catalysis is promising for water treatment. Solid catalysts play governing roles. Herein, the surface-disordered WO3, D-WO3, engineered with surface and sub-surface defective sites from NaBH4 reduction was proven to be an effective catalyst for H2O2 activation. The defective degree and defects amount on WO3 were regulated by NaBH4. More than 95% of two typical azo dyes, RhB and MG, were selectively degraded in D-WO3/H2O2 system during 3.0 h, while no significant activity was observed for MO as well as bisphenol A, roxarsone, phenol, 4-chlorophenol, p-nitrophenol, o-aminophenol, urea, and 2,4-dichlorophenol in comparison under the identical conditions (mainly less than 20%). Both ESR and radical scavenging tests indicated the minor role of ·OH from H2O2 activation on D-WO3. The superior activity of D-WO3 could be mainly attributed to the surface and sub-surface defects with finely tailored local atomic configurations and electronic structures of central metal sites. Surface and sub-surface defective sites could serve as the reactive sites of interfacial adsorption, dissociative activation, and catalytic decomposition for both oxidant and pollutants, with high adsorption energy, strong structural activation, and superior catalytic activity. Our findings provided a new chance for non-selective radical catalysis based on transition metal oxides and a promising catalyst with high performance, low cost, and no toxicity for pollutant degradation with weak matrix effects in wastewater and surface water.
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Affiliation(s)
- Ai-Yong Zhang
- Department of Municipal Engineering, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China.
| | - Pin-Cheng Zhao
- Department of Municipal Engineering, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yuan-Yi He
- Department of Municipal Engineering, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yang Zhou
- Department of Municipal Engineering, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Jing-Wei Feng
- Department of Municipal Engineering, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China.
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Tang CF, Liu SC, Feng Y, Mei HF, Liu HP, Feng JW, Ye LX, Wang GQ, Liu L, Huang YL. [Newborn screening program and blood amino acid profiling in early neonates with citrin deficiency]. Zhonghua Er Ke Za Zhi 2019; 57:797-801. [PMID: 31594068 DOI: 10.3760/cma.j.issn.0578-1310.2019.10.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the profiles of blood amino acid and acylcarnitine in early neonates with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and the sensitivity of newborn screening, and to explore potential biochemical metabolic markers for newborn screening program. Methods: Amino acid and acylcarnitine profiles in dried blood spots of newborn screening program were analyzed by tandem mass spectrometry (MS/MS). A total of 158 651 neonates born in Guangzhou from January 1, 2015 to June 30, 2019 were enrolled in this newborn screening program, and additionally 55 patients with NICCD confirmed by SLC25A13 gene analysis in Guangzhou Women and Children Medical Center were included in this study. NICCD screen-positive was defined as the cutoff value of citrulline (Cit) ≥ 30 μmol/L. The values of blood sampling time of the true positive group and those of the false negative group were compared by t-test. The levels of amino acid and acylcarnitine among different groups, including true positive group (Cit≥30 μmol/L), false negative group (Cit 21-<30 μmol/L and Cit<21 μmol/L) and the normal control group, were analyzed by F test, respectively. Results: Among 158 651 neonates, 39 neonates were positive for NICCD screening. Three of them were confirmed NICCD and 4 cases were found to be false negatives. The positive predictive value was 7.7% and the sensitivity was about 43.0%. Among 55 patients with NICCD, 18 cases (18/55, 32.7%) were true positives and 37 cases (37/55, 67.3%) were false negatives based on the cutoff value of citrulline in the dried blood spots for newborn screening. The blood sampling time was significantly different between true positive group and false negative group ((4.28±1.6) vs. (2.98±0.74) d, t=4.06, P<0.01). The increased levels of tyrosine((176.0±98.4) μmol/L), methionine ((37.0±26.9) μmol/L) and phenylalanine ((133.0±80.9)μmol/L) in Cit≥30 μmol/L group (n=18) were significantly different as compared with those in the other three groups, respectively (F=117.0, 58.5, 135.0, P<0.01). The levels of arginine ( (10.0±9.2) , (11.0±9.3) , (9.0±17.8) μmol/L), valine ( (119.0±29.8) , (107.6±14.1) , (102±68) μmol/L) and leucine ( (167.0±37.1) , (161.0±37.7) , (163.5±180.6) μmol/L) were not statistically significant among groups of Cit≥30 μmol/L(n=18), Cit21-<30 μmol/L(n=7) and Cit<21μmol/L(n=30,P>0.05), but they were significantly higher than those of the normal control group ((4±3), (78±21), (114.0±31.5) μmol/L, n=1 000), respectively(F=30.1, 23.0, 29.8, P<0.01). Alanine (Ala) ( (150±50) , (156.0±30.2), (168±105), (152±52) μmol/L) levels showed no significant difference (F=0.86, P>0.05) but the ratios of Ala/Cit (1.52±1.44, 6.82±1.56, 12.06±7.71, 19.42±6.27) decreased significantly among the four groups (F=69.0, P<0.05). The acylcarnitine levels showed no statistically significant results among the different groups (P>0.05). With Cit≥30 μmol/L and Ala/Cit<7.5 as cutoff values, the number of screen-positive cases reduced from 39 to 22 cases with no additional false negative case. With Cit≥21 μmol/L and Ala/Cit<7.5 as cutoff values the number of screen-positive cases increased to 117 cases with 1 additional true positive. Conclusions: The profiles of blood amino acid in early neonates with NICCD present the increased levels of multiple amino acids including citrulline, tyrosine, methionine and phenylalanine, and decreased ratio of Ala/Cit. Taking citrulline and ratio of Ala/Cit as screening markers can improve the positive predictive value appropriately. The limited sensitivity of NICCD newborn screening may be related to early blood sampling time.
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Affiliation(s)
- C F Tang
- Guangzhou Newborn Screening Center, Guangzhou Women and Children's Medical Center, Guangzhou 510180, China
| | - S C Liu
- Guangzhou Newborn Screening Center, Guangzhou Women and Children's Medical Center, Guangzhou 510180, China
| | - Y Feng
- Guangzhou Newborn Screening Center, Guangzhou Women and Children's Medical Center, Guangzhou 510180, China
| | - H F Mei
- Genetics and Endocrinology Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou 510623, China
| | - H P Liu
- Foshan Newborn Screening Center, Foshan Women and Children's Hospital, Foshan 528000, China
| | - J W Feng
- Yunfu Newborn Screening Center, Yunfu Women and Children's Hospital, Yunfu 527300, China
| | - L X Ye
- Dongguan Newborn Screening Center, Dongguan Women and Children's Hospital, Dongguan 523000, China
| | - G Q Wang
- Zhuhai Newborn Screening Center, Zhuhai Women and Children's Hospital, Zhuhai 523000, China
| | - L Liu
- Genetics and Endocrinology Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou 510623, China
| | - Y L Huang
- Guangzhou Newborn Screening Center, Guangzhou Women and Children's Medical Center, Guangzhou 510180, China
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Zhang AY, He YY, Lin T, Huang NH, Xu Q, Feng JW. A simple strategy to refine Cu 2O photocatalytic capacity for refractory pollutants removal: Roles of oxygen reduction and Fe(II) chemistry. J Hazard Mater 2017; 330:9-17. [PMID: 28208094 DOI: 10.1016/j.jhazmat.2017.01.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/26/2016] [Accepted: 01/25/2017] [Indexed: 06/06/2023]
Abstract
Visible-light-driven photocatalysis is a promising technology for advanced water treatment, but it usually exhibits a low efficiency. Cu2O is a low-cost semiconductor with narrow band gap, high absorption coefficient and suitable conduction band, but suffers from low charge mobility, poor quantum yield and weak catalytic performance. Herein, the Cu2O catalytic capacity for refractory pollutants degradation is drastically improved by a simple and effective strategy. By virtue of the synergistic effects between photocatalysis and Fenton, a novel and efficient photocatalysis-driven Fenton system, PFC, is originally proposed and experimentally validated using Cu2O/Nano-C hybrids. The synergistic PFC is highly Nano-C-dependent and exhibits a significant superiority for the removal of rhodamine B and p-nitrophenol, two typical refractory pollutants in wastewater. The PFC superiority is mainly attributed to: (1) the rapid photo-electron transfer driven by Schottky-like junction, (2) the selective O2 reduction mediated by semi-metallic Nano-C for efficient H2O2 generation, (3) the specific H2O2 activation and large OH generation catalyzed by Haber-Weiss Fenton mechanism, and (4) the accelerated Fe2+/Fe3+ cycling and robust Fe2+ regeneration via two additional pathways. Our findings might provide a new chance to overcome the intrinsic challenges of both photocatalysis and Fenton, as well as develop novel technology for advanced water treatment.
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Affiliation(s)
- Ai-Yong Zhang
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China.
| | - Yuan-Yi He
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Tan Lin
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Nai-Hui Huang
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Qiao Xu
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Jing-Wei Feng
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China.
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Ren WL, Fan YF, Feng JW, Zhong YB, Yu JB, Ren ZM, Liaw PK. Non-monotonic changes in critical solidification rates for stability of liquid-solid interfaces with static magnetic fields. Sci Rep 2016; 6:20598. [PMID: 26846708 PMCID: PMC4742885 DOI: 10.1038/srep20598] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 01/07/2016] [Indexed: 11/17/2022] Open
Abstract
We report the magnetic field dependence of the critical solidification rate for the stability of liquid-solid interfaces. For a certain temperature gradient, the critical solidification rate first increases, then decreases, and subsequently increases with increasing magnetic field. The effect of the magnetic field on the critical solidification rate is more pronounced at low than at high temperature gradients. The numerical simulations show that the magnetic-field dependent changes of convection velocity and contour at the interface agree with the experimental results. The convection velocity first increases, then decreases, and finally increases again with increasing the magnetic field intensity. The variation of the convection contour at the interface first decreases, then increases slightly, and finally increases remarkably with increasing the magnetic field intensity. Thermoelectromagnetic convection (TEMC) plays the role of micro-stirring the melt and is responsible for the increase of interface stability within the initially increasing range of magnetic field intensity. The weak and significant extents of the magneto-hydrodynamic damping (MHD)-dependent solute build-up at the interface front result, respectively, in the gradual decrease and increase of interfacial stability with increasing the magnetic field intensity. The variation of the liquid-side concentration at the liquid-solid interface with the magnetic field supports the proposed mechanism.
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Affiliation(s)
- W L Ren
- State Key Laboratory of Advanced Special Steel, College of Materials Science and Engineering, Shanghai University, Shanghai 200072, PR China
| | - Y F Fan
- State Key Laboratory of Advanced Special Steel, College of Materials Science and Engineering, Shanghai University, Shanghai 200072, PR China
| | - J W Feng
- State Key Laboratory of Advanced Special Steel, College of Materials Science and Engineering, Shanghai University, Shanghai 200072, PR China
| | - Y B Zhong
- State Key Laboratory of Advanced Special Steel, College of Materials Science and Engineering, Shanghai University, Shanghai 200072, PR China
| | - J B Yu
- State Key Laboratory of Advanced Special Steel, College of Materials Science and Engineering, Shanghai University, Shanghai 200072, PR China
| | - Z M Ren
- State Key Laboratory of Advanced Special Steel, College of Materials Science and Engineering, Shanghai University, Shanghai 200072, PR China
| | - P K Liaw
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN37996, USA
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Zhu D, Jiang L, Liu RL, Chen P, Lang L, Feng JW, Yuan SJ, Zhao DY. Wire-cylinder dielectric barrier discharge induced degradation of aqueous atrazine. Chemosphere 2014; 117:506-514. [PMID: 25268075 DOI: 10.1016/j.chemosphere.2014.09.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 09/04/2014] [Accepted: 09/04/2014] [Indexed: 06/03/2023]
Abstract
The wire-cylinder dielectric barrier discharge reactor was adopted for removal of aqueous atrazine. The effect of different parameters on the degradation efficiency of atrazine was investigated, and the degradation mechanism of atrazine was studied. The experimental results showed that when the discharge power was 50 W and the air flow rate was 140 L h(-1), 93.7% of atrazine was degraded after 18 min of discharge time. The concentrations of generated O3 and H2O2 increased with increasing discharge time. The pH decreased from 6.80 to 2.50, 12.7% of TOC was removed after 18 min. The concentrations of generated Cl(-) and NO3(-) increased significantly during the degradation process of atrazine, and the decreasing toxicity trend was observed for the treated atrazine solution. The degradation byproducts of atrazine were identified using liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS), which might be formed mainly in dechlorination hydroxylation, alkyl oxidation, dechlorination hydroxylation combined with alkyl oxidation and demethylation oxidation reactions.
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Affiliation(s)
- Dan Zhu
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Lin Jiang
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Run-Long Liu
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Pei Chen
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Lin Lang
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Jing-Wei Feng
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China.
| | - Shou-Jun Yuan
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, China.
| | - Da-Yong Zhao
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China
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Abstract
Bioglass, a clinically used bone graft material, has been tested in vitro in a simulated body fluid (SBF) up to four weeks. Apatite crystals were not only found to form on its surface but also in the reaction solutions. The apatite crystals have been examined by high-resolution transmission electron microscopy (TEM). The crystals formed in the solutions appear identical in morphology and structure with those formed on the Bioglass surface. It may be that the soluble Si in the solution serves as the nucleating site for the apatite crystal or that apatite nuclei are released from the Bioglass surface to the solution resulting in crystal growth.
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Affiliation(s)
- J P Zhong
- US Biomaterials Corporation, Alachua, FL, USA
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Feng JW, Jin GJ, Hu A, Kang SS, Jiang SS, Feng D. Magnetostatic modes in Fibonacci magnetic and nonmagnetic multilayers. Phys Rev B Condens Matter 1995; 52:15312-15318. [PMID: 9980887 DOI: 10.1103/physrevb.52.15312] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Du YX, Chen JK, Wu ZL, Feng JW, Chen XW, Gao HG. The observation of some biological characteristics of transformed cells induced by MNNG in vitro. Mutat Res 1986; 162:91-104. [PMID: 3014323 DOI: 10.1016/0027-5107(86)90074-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The early passage diploid Syrian hamster embryo (SHE) cells were treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The treated cells proliferated rapidly; the doubling times shortened; colonies appeared in solid agar medium and transformed foci formed in tissue culture. All of these phenomena suggest that malignant transformation of SHE cell has occurred. Faster cell division rate and multipolar mitosis were demonstrated by time-lapse cinemicrography and scanning electron microscopy. Multipolar mitosis can occur in two forms: direct division and indirect division. The transformed cells were more abundant in microvilli, the number of which increased in accordance with the degree of malignancy. In comparison with the controls, the transformed cells expressed a greater tritiated thymidine incorporation, greater DNA contents and more chromosomes, but no difference in nuclear area. The determination of amino acid changes in media due to the growth of transformed cells showed that the decrease in arginine and increase in ornithine are significant. The results of allogenic animal inoculation suggest that the transformed cells can be characterized into several different stages in the process of transformation.
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