Electrostatic self-assembly of a AgI/Bi2Ga4O9 p–n junction photocatalyst for boosting superoxide radical generation

2020 ◽  
Vol 8 (7) ◽  
pp. 4083-4090 ◽  
Author(s):  
Jin Liu ◽  
Xingcai Zhang ◽  
Qian Zhong ◽  
Jun Li ◽  
Hongzhang Wu ◽  
...  

A novel AgI/Bi2Ga4O9 p–n junction photocatalyst was synthesized by an electrostatic self-assembly approach. Characterization and DFT calculations show that the formation of the p–n junction greatly boosts the generation of superoxide radicals.

2015 ◽  
Vol 51 (37) ◽  
pp. 7931-7934 ◽  
Author(s):  
Fang Si ◽  
Yang Liu ◽  
Kelu Yan ◽  
Wenwan Zhong

A fluorogenic probe with mitochondria targeting capability was prepared for detection of superoxide radical generation inside mitochondria in living cells.


2008 ◽  
Vol 77 (12) ◽  
pp. 123706 ◽  
Author(s):  
Tsuyoshi Miyazaki ◽  
David R. Bowler ◽  
Michael J. Gillan ◽  
Takahisa Ohno

1999 ◽  
Vol 337 (3) ◽  
pp. 531 ◽  
Author(s):  
Eduardo LÓPEZ-HUERTAS ◽  
Francisco J. CORPAS ◽  
Luisa M. SANDALIO ◽  
Luis A. DEL RÍO

2009 ◽  
Vol 6 (s1) ◽  
pp. S79-S86 ◽  
Author(s):  
Vikesh Kumar ◽  
M. R. Tripathi ◽  
Manish Kumar ◽  
Gopal Shukla ◽  
Sarvesh Dwivedi ◽  
...  

There are several low lying singlet oxygen (1O2) and superoxide radical (O-2) which are important in photochemical oxidation. In our present analysis we are studying chemical property of singlet oxygen (1O2) and super oxide radical (O-2) and some dyestuffs species to produce reactive oxygen such as singlet oxygen1O2and superoxide radicals. Irradiation with sun lightin vitrothe dyestuff like benzanthrone, metanil yellow andp-aminodiphenylamine were found to produce reactive oxygen species such as singlet oxygen (1O2) and/or superoxide radicals (O-2) .The dose response relationship between singlet1O2production when sunlight expose of those dyestuffs (0-25 min), and (0-12 min) for super oxide (O-2) production were studied. However benzanthrone produces detectable amount of1O2, Although metanil yellow andp-aminodiphenylamine (p-ADPA) did not produce detectable amounts of1O2under similar conditions. The above dye stuffs are routinely used in textiles, cosmetics, detergents, leather industries as well as food additives and role of these activated oxygen species in the development of skin diseases.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Chai-Hyeon Lee ◽  
Ye-Na Park ◽  
Hyeung-Rak Kim ◽  
Sang Gil Lee ◽  
Bohkyung Kim

Abstract Objectives It has been a long time since seaweeds have been used for food ingredients in Asian countries. Recently, a body of research has revealed the health benefits of bioactive compounds in seaweeds, especially their antioxidant capacities. Although numerous seaweeds inhabit in the ocean, only a small percentage has been explored for functional food. Therefore, the purpose of this study was to analyze the antioxidant capacities of various seaweeds grown off the Korean coast to screen for the potential functional food sources. Methods Ten ethanol extracts of Korean seaweeds were provided by the National Marine Biodiversity Institute of Korea, which included Scytosiphon gracilis, Scytosiphon lomentaria, Sargassum muticum, Sargassum confusum, Petrospongium rugosum, Sargassum fusiforme, Petalonia fascia, Sargassum nigrifolium, Ishige foliacea, and Myelophycus simplex. Hundred mg/L of samples in 80% methanol was used to measure their ABTS, DPPH, and superoxide radical scavenging activities. Mg vitamin C equivalent antioxidant capacity (VCEAC)/100 mg was used to express the ABTS and DPPH radical scavenging capacities. For the superoxide radical scavenging capacity, inhibition rate of superoxide radical generation (%) was calculated. Results Among the ten seaweeds, S. nigrifolium and I. foliacea exhibited the most significant radical scavenging capacities. DPPH radical scavenging capacities of I. foliacea and S. nigrifolium were 122.4 mg VCEAC/100 mg and 95.8 mg VCEAC/100 mg, respectively. For ABTS radical scavenging capacity, I. foliacea exhibited 178.5 mg VCEAC/100 mg, followed by S. nigrifolium as 80.9 mg VCEAC/100 mg. I. foliacea inhibited about 68% of superoxide radical generation followed by S. nigrifolium (40.6%) while vitamin C as positive control inhibited about 28.9% of superoxide radical generation. The antioxidant capacities measured by the three assays were positively correlated with each other. Conclusions The current study explored total antioxidant capacities of various Korean seaweeds and found I. foliacea and S. nigrifolium as the most potential antioxidant-rich food resources. Further research would be warranted to investigate bioactive compounds from S. nigrifolium and I. foliacea. Funding Sources This work was supported by the Pukyong National University Research Fund in 2018.


1997 ◽  
Vol 273 (4) ◽  
pp. H1677-H1687 ◽  
Author(s):  
Zhi-Qing Zhao ◽  
James C. Todd ◽  
Hiroki Sato ◽  
Xin-Liang Ma ◽  
J. Vinten-Johansen

This study tests the hypothesis that cardioprotection exerted by adenosine A2-receptor activation and neutrophil-related events involves stimulation of ATP-sensitive potassium (KATP) channels on neutrophils during reperfusion. The adenosine A2 agonist CGS-21680 (CGS) inhibited superoxide radical generation from isolated rabbit polymorphonuclear neutrophils (PMNs) in a dose-dependent manner from 17.7 ± 2.1 to 7.4 ± 1.3 nmol/5 × 106 PMNs ( P < 0.05). Pinacidil, a KATP-channel opener, partially inhibited superoxide radical production, which was completely reversed by glibenclamide (Glib). Incremental doses of Glib in combination with CGS (1 μM) did not alter CGS-induced inhibition of superoxide radical generation. CGS significantly reduced PMN adherence to the endothelial surface of aortic segments in a dose-dependent manner from 189 ± 8 to 50 ± 6 PMNs/mm2( P < 0.05), which was also not altered by incremental doses of Glib. Infusion of CGS (0.025 mg/kg) before reperfusion reduced infarct size from 29 ± 2% in the Vehicle group to 15 ± 1% in rabbits undergoing 30 min of ischemia and 120 min of reperfusion ( P< 0.05). Glib (0.3 mg/kg) did not change the infarct size (28 ± 2%) vs. the Vehicle group and did not attenuate infarct size reduction by CGS (16 ± 1%). Glib did not change blood glucose levels. Cardiac myeloperoxidase activity was decreased in the ischemic tissue of the CGS group (0.15 ± 0.03 U/100 mg tissue) compared with the Vehicle group (0.37 ± 0.05 U/100 mg tissue; P < 0.05). We conclude that adenosine A2 activation before reperfusion partially reduces infarct size by inhibiting neutrophil activity and that this effect does not involve KATP-channel stimulation.


2020 ◽  
Vol 22 (13) ◽  
pp. 6942-6952 ◽  
Author(s):  
Laura Le Bras ◽  
Roxanne Berthin ◽  
Ismaïl Hamdi ◽  
Maroua Louati ◽  
Stéphane Aloïse ◽  
...  

The behaviour of light-responsive supramolecular assemblies is rationalized with the help of molecular dynamics and TD-DFT calculations.


BIOPHYSICS ◽  
2007 ◽  
Vol 52 (6) ◽  
pp. 582-586 ◽  
Author(s):  
I. V. Sviryaeva ◽  
E. K. Ruuge ◽  
K. B. Shumaev

Author(s):  
Hongwei Song ◽  
Olusegun J. Ilegbusi

A mathematical model is developed to describe the transport phenomena and electrochemical reaction kinetics during amperometric measurement of superoxide radical concentration using ZnO-polymer nanocomposite sensor. This model assumes a logarithmic normal distribution for the nanoparticles immobilized in the polymer matrix and an empirical relation for the diffusion coefficient of superoxide radicals as a function of pore volume fraction. A kinetic with secondary order rate constant is used to represent the electrochemical reactions of electron transfer from the superoxide radicals to nanoparticles. The predicted results include the effect of diffusion coefficient on concentration and electrical conductivity.


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