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1. Curing kinetic of self-promoted alicyclic-based bisphthalonitrile monomer

Author:
Lv, Jiangbo; Liu, Zhengzhou; Li, Renke; Liu, Yao; Hu, Jianghuai; Zeng, Ke; Yang, Gang
Source:
Thermochimica acta 2020 v.683 pp. 178446
ISSN:
0040-6031
Subject:
free radicals,   etc   ; catalytic activity; models;     Show all 3 Subjects
Abstract:
... Self-promoted alicyclic-based phthalonitrile possesses outstanding properties, which would be determined by the special free radical curing mechanism and curing process. Thus, the curing kinetic of alicyclic-based phthalonitrile was studied and the curing kinetic parameters were determined by DSC at various heating rates. Double fit peaks were used to analyze the reaction processes. The autocataly ...
DOI:
10.1016/j.tca.2019.178446

2. Standard and transformed values of gibbs energy formation for some radicals and ions involved in biochemical reactions

Author:
Bazhin, N.M.
Source:
Archives of biochemistry and biophysics 2020 v.686 pp. 108282
ISSN:
0003-9861
Subject:
free radicals,   etc   ; chemical reactions; energy; ions; thermodynamics;     Show all 5 Subjects
Abstract:
... The standard and transformed values of the Gibbs formation function of a number of radicals and ions are calculated: H, OH, HO2,O, SH, NH₂, CH₃, H⁺,O−,OH−HO2−, O2−,SH−NH2−, Q−, NAD*, FMN⁻, FAD⁻. These data can be used in consideration of the thermodynamics of biochemical reactions involving free radicals. ...
DOI:
10.1016/j.abb.2020.108282

3. Numerical study on electron energy distribution characteristics and evolution of active particles of methanol-air mixture by non-equilibrium plasma

Author:
Gong, Changming; Yi, Lin; Wang, Kang; Huang, Kuo; Liu, Fenghua
Source:
Energy 2020 v.193 pp. 116881
ISSN:
0360-5442
Subject:
free radicals,   etc   ; combustion; economics; electric field; ionization;     Show all 5 Subjects
Abstract:
... The extent of combustion enhancement by non-equilibrium plasma strongly depends on the electric field and electron number density. The electron energy distribution characteristics and evolution of active particles of methanol-air mixture by non-equilibrium plasma were numerical simulated. As an introductory work in this field, this study only partially cited other people’s data for comparative ver ...
DOI:
10.1016/j.energy.2019.116881

4. Methyl and Hydrogen Transfer in Free Radical Reactions

Author:
Tannous, Joy H.; de Klerk, Arno
Source:
Energy & fuels 2020 v.34 no.2 pp. 1698-1709
ISSN:
1520-5029
Subject:
free radicals,   etc   ; homolytic cleavage; hydrogen; methane; moieties;     Show all 5 Subjects
Abstract:
... It was speculated that hydrogen transfer was not the only type of transfer reaction that could take place during thermal conversion, and that methyl transfer could also take place. There was a large body of literature on intramolecular methyl migration, but little mention of intermolecular methyl transfer as a potentially important reaction type in free radical systems. Methyl transfer during ther ...
DOI:
10.1021/acs.energyfuels.9b04213

5. Correction to: Rate constants for the reactions of OH radicals with CF3CX=CY2 (X=H, F, CF3, Y=H, F, Cl)

Author:
Tokuhashi, Kazuaki; Takizawa, Kenji; Kondo, Shigeo
Source:
Environmental science and pollution research international 2020 v.27 no.3 pp. 3542-3543
ISSN:
0944-1344
Subject:
free radicals,   etc   ; chlorine; fluorine; hydroxyl radicals;     Show all 4 Subjects
Abstract:
... We make a correction to the original paper because there was a mistake in our preceding paper (Tokuhashi et al. 2018) that was cited in the original paper. In our preceding paper, we reported the measured rate constant of OH radicals with (E)-CHF=CHF. ...
DOI:
10.1007/s11356-019-07376-0

6. Natural iron ligands promote a metal-based oxidation mechanism for the Fenton reaction in water environments

Author:
Farinelli, Giulio; Minella, Marco; Pazzi, Marco; Giannakis, Stefanos; Pulgarin, Cesar; Vione, Davide; Tiraferri, Alberto
Source:
Journal of hazardous materials 2020 v.393 pp. 122413
ISSN:
0304-3894
Subject:
free radicals,   etc   ; catalytic activity; cyclohexanones; iron; ligands; oxidation; pH; sludge;     Show all 8 Subjects
Abstract:
... The Fenton reaction is an effective advanced oxidation process occurring in nature and applied in engineering processes toward the degradation of harmful substances, including contaminants of emerging concern. The traditional Fenton application can be remarkably improved by using iron complexes with organic ligands, which allow for the degradation of contaminants at near-neutral pH and for the red ...
DOI:
10.1016/j.jhazmat.2020.122413

7. Peroxymonosulfate decomposition by homogeneous and heterogeneous Co: Kinetics and application for the degradation of acetaminophen

Author:
Rodríguez-Narvaez, Oscar M.; Rajapaksha, Ruwini D.; Ranasinghe, Mahinda I.; Bai, Xuelian; Peralta-Hernández, Juan Manuel; Bandala, Erick R.
Source:
Journal of environmental sciences (China) 2020 v.93 pp. 30-40
ISSN:
1001-0742
Subject:
free radicals,   etc   ; acetaminophen; byproducts; cobalt; cobalt oxide; hydroxyl radicals; kinetics;     Show all 7 Subjects
Abstract:
... Peroxymonosulfate (PMS) decomposition, hydroxyl radical (•OH) generation, and acetaminophen (ACT) degradation by the Co/PMS system using homogeneous (dissolved cobalt) and heterogeneous (suspended Co₃O₄) cobalt were assessed. For the homogeneous process, >99% PMS decomposition was observed and 10 mmol/L of •OH generation was produced using 5 mmol/L of PMS and different dissolved cobalt concentrati ...
DOI:
10.1016/j.jes.2020.03.002

8. The stannylvinyl cation that never was! New concentration- and temperature-dependent probe studies confirm an entirely free radical mechanism and O–Sn coordinative control of the hydrostannation of propargylically-oxygenated dialkyl acetylenes with stannanes and cat. Et3B

Author:
Watson, Hamish A.; Manaviazar, Soraya; Steeds, Hannah G.; Hale, Karl J.
Source:
Tetrahedron 2020 v.76 no.20 pp. 131061
ISSN:
0040-4020
Subject:
free radicals,   etc   ; alkynes; cations; chemical reactions; chemical structure; methanol;     Show all 6 Subjects
Abstract:
... O-Directed free radical hydrostannation of the β-cyclopropyl propargyl alcohol 57 with stannanes and cat. Et₃B in THF/H₂O or PhMe/MeOH failed to deliver any of the expected products of α-stannylvinyl cation capture. Instead only α-stannyl-β-cyclopropylvinyl radical intermediates were detected, which underwent fast H-atom abstraction and/or cyclopropane ring-opening as a result of eliminative β-sci ...
DOI:
10.1016/j.tet.2020.131061

9. Access to Unnatural α-Amino Acids via Visible-Light-Mediated Decarboxylative Conjugate Addition to Dehydroalanine

Author:
Shah, Akshay A.; Kelly, Michael J.; Perkins, James J.
Source:
Organic letters 2020 v.22 no.6 pp. 2196-2200
ISSN:
1523-7052
Subject:
free radicals,   etc   ; amino acids; carboxylic acids; moieties; photocatalysis; photocatalysts;     Show all 6 Subjects
Abstract:
... An expedient synthesis of β-alkyl α-amino acids is reported via application of decarboxylative photocatalysis. The method utilizes abundant, diverse, and inexpensive carboxylic acids to provide radicals for conjugate addition to dehydroalanine ester. High-throughput experimentation revealed an acridinium-based photocatalyst, tetraMeO-Acri-N-diMeOPh, to be the optimal choice enabling a general meth ...
DOI:
10.1021/acs.orglett.0c00371

10. Nitroxyl radical-catalyzed chemoselective alcohol oxidation for the synthesis of polyfunctional molecules

Author:
Shibuya, Masatoshi
Source:
Tetrahedron letters 2020 v.61 no.8 pp. 151515
ISSN:
0040-4039
Subject:
free radicals,   etc   ; catalytic activity; chemical structure; chemoselectivity; derivatization; oxidation; polyols;     Show all 7 Subjects
Abstract:
... Alcohol oxidation is one of the most principal transformations used in organic synthesis. During the development of these oxidation methods, chemoselective oxidation of a specific alcohol in a polyol has enabled the discrimination of multiple hydroxy groups, which can increase the synthetic efficiency by reducing the use of protecting groups. This digest highlights recent topics of the catalytic s ...
DOI:
10.1016/j.tetlet.2019.151515

11. Halide-induced dissolution of lead(IV) oxide in frozen solution

Author:
Menachery, Sunil Paul M.; Menacherry, Sunil Paul M.; Min, Dae Wi; Jeong, Daun; Aravindakumar, Charuvila T.; Lee, Woojin; Choi, Wonyong
Source:
Journal of hazardous materials 2020 v.384 pp. 121298
ISSN:
0304-3894
Subject:
free radicals,   etc   ; aqueous solutions; chlorides; ice; ions; lead; pH;     Show all 7 Subjects
Abstract:
... The dark dissolution behavior of plattnerite (ß-PbO₂) was investigated in frozen solutions containing halide ions and compared with those in aqueous solution. The amount of dissolved lead in the frozen solutions varied depending on the solution pH and the kind and concentration of halide ions. The presence of bromide and iodide ions enhanced the dissolution of lead in the aqueous phase, whereas th ...
DOI:
10.1016/j.jhazmat.2019.121298

12. Radical Clock Probes to Determine Carbohydrate Radical Stabilities

Author:
Mai-Linde, Yasemin; Linker, Torsten
Source:
Organic letters 2020 v.22 no.4 pp. 1525-1529
ISSN:
1523-7052
Subject:
free radicals,   etc   ; chemical reactions; chemical structure; hexoses; organic compounds; pentoses;     Show all 6 Subjects
Abstract:
... Carbohydrate radical stabilities in the 1- and 2-position have been determined by a radical clock approach, starting from cyclopropanated sugars with xanthates as precursors. Various hexoses and pentoses afforded 1-deoxy sugars as main products, indicating that anomeric radicals are more stable than radicals in the 2-position. An additional influence of the configurations on radical stabilities ha ...
DOI:
10.1021/acs.orglett.0c00111

13. The Role of Antimicrobial Neutrophil Extract in Modification of the Inflammatory Response During Osteochondral Autograft and Allograft Transplantation in Rabbits

Author:
Wessely-Szponder, J.; Michalska, J.; Szponder, T.; Żylińska, B.; Tarczyńska, M.; Szubstarski, M.
Source:
Journal of comparative pathology 2020 v.175 pp. 49-63
ISSN:
0021-9975
Subject:
free radicals,   etc   ; allografting; autografting; cartilage; inflammation; macrophages; neutrophils; phenotype; rabbits;     Show all 9 Subjects
Abstract:
... Osteochondral autograft or allograft transplantation is one of the surgical options for the management of large cartilage defects; however, the mechanisms of cartilage healing after this procedure, especially the immunological mechanisms, are not fully understood. The present study examined whether a grafting procedure changed the in-vitro responses of neutrophils and monocyte-derived macrophages ...
DOI:
10.1016/j.jcpa.2019.12.007

14. Persulfate-based photodegradation of a beta-lactam antibiotic amoxicillin in various water matrices

Author:
Kattel, Eneliis; Kaur, Balpreet; Trapido, Marina; Dulova, Niina
Source:
Environmental technology 2020 v.41 no.2 pp. 202-210
ISSN:
1479-487X
Subject:
free radical scavengers,   etc   ; amoxicillin; iron; mineralization; photolysis; reaction kinetics;     Show all 6 Subjects
Abstract:
... Amoxicillin (AMX), a widely used beta-lactam antibiotic, belongs to the World Health Organization’s list of essential medicines. This subsequently causes its long-term presence in the environment and therefore, affects different environmental compartments. In this research, the degradation and mineralisation of AMX by UVC-activated persulfate-based treatment in various aqueous media was assessed. ...
DOI:
10.1080/09593330.2018.1493149

15. Role of Gas Coal in Directional Regulation of Sulfur during Coal-Blending Coking of High Organic-Sulfur Coking Coal

Author:
Shen, Yanfeng; Wang, Meijun; Wu, Yucheng; Hu, Yongfeng; Kong, Jiao; Duan, Xiaobao; Wang, Jiancheng; Chang, Liping; Bao, Weiren
Source:
Energy & fuels 2020 v.34 no.3 pp. 2757-2764
ISSN:
1520-5029
Subject:
free radicals,   etc   ; coal; hydrogen; minerals; ovens; prices; pyrolysis; sulfur;     Show all 8 Subjects
Abstract:
... A high organic-sulfur coking coal and two high-volatile gas coals were selected to partially replace a low-sulfur coking coal in an industrial coal blend. The effects of various coal properties on directional regulation of sulfur during coal blend pyrolysis were investigated by a lab-scale fixed-bed reactor, and the coke quality indices were evaluated by a 10 kg-scale coke oven. After adding gas c ...
DOI:
10.1021/acs.energyfuels.9b03737

16. Origin of Free Radical Persistence in Asphaltenes: Cage Effect and Steric Protection

Author:
Alili, Aytan S.; Siddiquee, Muhammed N.; de Klerk, Arno
Source:
Energy & fuels 2020 v.34 no.1 pp. 348-359
ISSN:
1520-5029
Subject:
free radicals,   etc   ; air; asphaltenes; hydrogen; models; nitrogen; petroleum; toluene; viscosity;     Show all 9 Subjects
Abstract:
... Heavier petroleum fractions contain persistent free radicals, and the highest concentration of persistent free radicals is usually found in asphaltenes. The origin of free radical persistence was studied. The potential influence of exposure to air, free radical caging, and steric protection was evaluated. The free radical content of asphaltenes diluted in toluene remained constant to within 5% ove ...
DOI:
10.1021/acs.energyfuels.9b03836

17. Electrochemical intramolecular C–H/N–H functionalization for the synthesis of isoxazolidine-fused isoquinolin-1(2H)-ones

Author:
Zhang, Lin-Bao; Geng, Rui-Sen; Wang, Zi-Chen; Ren, Guang-Yi; Wen, Li-Rong; Li, Ming
Source:
Green chemistry 2020 v.22 no.1 pp. 16-21
ISSN:
1463-9270
Subject:
free radicals,   etc   ; amides; electrochemistry; ethanol; green chemistry; solvents;     Show all 6 Subjects
Abstract:
... A general and practical protocol for the construction of isoxazolidine-fused isoquinolin-1(2H)-ones has been described by electrochemical-oxidation-induced intramolecular annulation via amidyl radicals. In an undivided cell, isoquinolinones could be easily generated from various available amides bearing CONHOR groups under metal-free, additive-free and external oxidant-free conditions. Moreover, t ...
DOI:
10.1039/c9gc03290h

18. Heterogeneous Fenton oxidation of paracetamol in aqueous solution using iron slag as a catalyst: Degradation mechanisms and kinetics

Author:
Van, Huu Tap; Nguyen, Lan Huong; Hoang, Trung Kien; Nguyen, Thi Tuyet; Tran, Thi Ngoc Ha; Nguyen, Thi Bich Hanh; Vu, Xuan Hoa; Pham, Minh Tan; Tran, Thi Pha; Pham, T.T.; Nguyen, Hai Duy; Chao, Huan-Ping; Lin, Chu-Ching; Nguyen, X.C.
Source:
Environmental technology & innovation 2020 v.18 pp. 100670
ISSN:
2352-1864
Subject:
free radical scavengers; free radicals,   etc   ; acetaminophen; adsorption; aqueous solutions; carbonates; catalysts; chemical oxygen demand; chlorides; ferrous oxide; hydrogen peroxide; iron; kinetics; oxidation; pH; silica; slags; zinc oxide;     Show all 18 Subjects
Abstract:
... In this study, a catalyst derived from iron slag (Fe-S) was used for heterogeneous Fenton oxidation (H2O₂/Fe-S) of paracetamol in aqueous solution; the conventional homogeneous Fenton reaction (H2O₂/Fe²＋) was run in parallel for comparison. Degradation of paracetamol, in terms of chemical oxygen demand (COD) removal, was found strongly dependent on the solution pH, with the maximum efficiency obta ...
DOI:
10.1016/j.eti.2020.100670

19. Enhanced degradation of triclosan by cobalt manganese spinel-type oxide activated peroxymonosulfate oxidation process via sulfate radicals and singlet oxygen: Mechanisms and intermediates identification

Author:
Chen, Zhiping; Bi, Sijing; Zhao, Guangyi; Chen, Yuancai; Hu, Yongyou
Source:
The Science of the total environment 2020 v.711 pp. 134715
ISSN:
0048-9697
Subject:
free radical scavengers; free radicals,   etc   ; catalysts; catalytic activity; cobalt; cycloaddition reactions; electron paramagnetic resonance spectroscopy; ions; manganese; oxidation; pH; singlet oxygen; sulfates; triclosan; voltammetry; wastewater treatment;     Show all 16 Subjects
Abstract:
... Spinel is a kind of desirable catalyst to activate peroxymonosulfate (PMS) for chemical oxidation of organic contaminants in wastewater treatment. However, apart from classic sulfate radical based AOPs (SR-AOPs), the generation and oxidative pathways of singlet oxygen (¹O₂) by Co/Mn spinels have been little explored in PMS catalysis. In this study, spinel-type oxide Co₂Mn₁O₄ was successfully synth ...
DOI:
10.1016/j.scitotenv.2019.134715

20. Preparative isolation of highly polar free radical inhibitor from Floccularia luteovirens using hydrophilic interaction chromatography directed by on-line HPLC-DPPH assay

Author:
Dang, Jun; Chen, Chengbiao; Ma, Jianbin; Dawa, YangZom; Wang, Qi; Tao, Yanduo; Wang, Qilan; Ji, Tengfei
Source:
Journal of chromatography 2020 v.1142 pp. 122043
ISSN:
1570-0232
Subject:
free radical scavengers; free radicals,   etc   ; antioxidant activity; chemical composition; electrospray ionization mass spectrometry; fungi; hydrophilic interaction chromatography; nuclear magnetic resonance spectroscopy; polar compounds; purification methods; screening; therapeutics;     Show all 12 Subjects
Abstract:
... Wild edible macro fungi Floccularia luteovirens proved to be a valuable source for the identification of novel lead molecules with therapeutic potential. Nevertheless, the chemical constituents of Floccularia luteovirens are rarely reported due to absence of efficient purification methods. In this study, a hydrophilic interaction chromatography directed by on-line HPLC-DPPH assay has been develope ...
DOI:
10.1016/j.jchromb.2020.122043