A biomass based free radical scavenger binder endowing a compatible cathode interface for 5 V lithium-ion batteries

2019 ◽  
Vol 12 (1) ◽  
pp. 273-280 ◽  
Author(s):  
Yue Ma ◽  
Kai Chen ◽  
Jun Ma ◽  
Gaojie Xu ◽  
Shanmu Dong ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Lithium Ion Batteries ◽  
High Voltage ◽  
Lithium Ion ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Cathode Interface

A lignin binder has been introduced to high voltage lithium-ion batteries to suppress electrolyte decomposition by scavenging free radicals.

scholarly journals Free Radical–Mediated Cell Damage After Experimental Status Epilepticus in Hippocampal Slice Cultures

2002 ◽  
Vol 88 (6) ◽  
pp. 2909-2918 ◽  
Author(s):  
Richard Kovács ◽  
Sebastian Schuchmann ◽  
Siegrun Gabriel ◽  
Oliver Kann ◽  
Julianna Kardos ◽  
...  
Keyword(s):  
Free Radicals ◽  
Status Epilepticus ◽  
Free Radical ◽  
Hippocampal Slice ◽  
Cell Damage ◽  
Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Mitochondrial Depolarization ◽  
Hippocampal Slice Cultures

Generation of free radicals may have a key role in the nerve cell damage induced by prolonged or frequently recurring convulsions (status epilepticus). Mitochondrial function may also be altered due to production of free radicals during seizures. We therefore studied changes in field potentials (fp) together with measurements of extracellular, intracellular, and intramitochondrial calcium concentration ([Ca2+]e, [Ca2+]i, and [Ca2+]m, respectively), mitochondrial membrane potential (ΔΨ), NAD(P)H auto-fluorescence, and dihydroethidium (HEt) fluorescence in hippocampal slice cultures by means of simultaneous electrophysiological and microfluorimetric measurements. As reported previously, each seizure-like event (SLE) resulted in mitochondrial depolarization associated with a delayed rise in oxidation of HEt to ethidum, presumably indicating ROS production. We show here that repeated SLEs led to a decline in intracellular and intramitochondrial Ca2+ signals despite unaltered Ca2+ influx. Also, mitochondrial depolarization and the NAD(P)H signal became smaller during recurring SLEs. By contrast, the ethidium fluorescence rises remained constant or even increased from SLE to SLE. After about 15 SLEs, activity changed to continuous afterdischarges with steady depolarization of mitochondrial membranes. Staining with a cell death marker, propidium iodide, indicated widespread cell damage after 2 h of recurring SLEs. The free radical scavenger, α-tocopherol, protected the slice cultures against this damage and also reduced the ongoing impairment of NAD(P)H production. These findings suggest involvement of reactive oxygen species (ROS) of mitochondrial origin in the epileptic cell damage and that free radical scavenging may prevent status epilepticus–induced cell loss.

Oxygen Free Radicals and the Effect of a Free Radical Scavenger in Patients with Intermittent Claudication

2000 ◽  
Vol 34 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Emmanuel J. Diamantopoulos ◽  
Dionisios Charitos ◽  
Vassilios Georgopoulos ◽  
Emmanuel Economou ◽  
Michael Sfakianakis ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Intermittent Claudication ◽  
Oxygen Free Radicals ◽  
Free Radical Scavenger ◽  
Radical Scavenger

scholarly journals Hypoxic but Not Ischemic Neurotoxicity of Free Radicals Revealed by Dynamic Changes in Glucose Metabolism of Fresh Rat Brain Slices on Positron Autoradiography

2000 ◽  
Vol 20 (2) ◽  
pp. 350-358 ◽  
Author(s):  
Naoto Omata ◽  
Tetsuhito Murata ◽  
Yasuhisa Fujibayashi ◽  
Atsuo Waki ◽  
Norihiro Sadato ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Rat Brain ◽  
Neuroprotective Effect ◽  
Brain Slices ◽  
Nmda Antagonist ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Dynamic Changes ◽  
K Value

Dynamic changes in the regional cerebral glucose metabolic rate induced by hypoxia/reoxygenation or ischemia/reperfusion were investigated with a positron autoradiography technique. Fresh rat brain slices were incubated with [18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) in oxygenated Krebs-Ringer solution at 36°C, and serial two-dimensional time-resolved images of [18F]FDG uptake in the slices were obtained. In the case of loading hypoxia (oxygen deprivation)/pseudoischemia (oxygen and glucose deprivation) for various periods of time, the net influx constant ( K) of [18F]FDG at preloading and after reoxygenation/pseudoreperfusion (post-loading) was quantitatively evaluated by applying the Patlak graphical method to the image data. Regardless of the brain region, with hypoxia lasting ≥20 minutes, the postloading K value was decreased compared with the unloaded control, whereas with pseudoischemia of ≤40 minutes, approximately the same level as the unloaded control was maintained. Next, the neuroprotective effect against hypoxia/pseudoischemia loading induced by the addition of a free radical scavenger or an N-methyl-D-aspartate (NMDA) antagonist was assessed by determining whether a decrease in the postloading K value was prevented. Whereas with 20-minute hypoxia, both agents exhibited a neuroprotective effect, in the case of 50-minute pseudoischemia, only the NMDA antagonist did so, with the free radical scavenger being ineffective. These results demonstrate that hypoxia causes irreversible neuronal damage within a shorter period than ischemia, with both free radicals and glutamate suggested to be involved in tandem in the neurotoxicity induced by hypoxia, whereas glutamate alone is involved in ischemic neurotoxicity.

Interaction of cytokinins with lipid-associated oxy free radicals during senescence: a prospective mode of cytokinin action

1984 ◽  
Vol 62 (12) ◽  
pp. 2943-2949 ◽  
Author(s):  
Ya'acov Y. Leshem
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Xanthine Oxidase ◽  
Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Formation ◽  
Radical Scavenger ◽  
Substrate Affinity ◽  
Xanthine Oxidase Inhibitors ◽  
Free Radical Formation

In senescence physiology, experimental data indicate causative relationships among cytokinin, lipoxygenation, anti-oxidation, and lipid-associated free radical scavenging. During both normal and induced senescence, there is a rise in lipoxygenase (LOX) which catalyzes the oxidation of polyunsaturated fatty acids containing the cis, cis-1,4-pentadiene configuration. These include linoleic and linolenic acids, which are of common occurrence in plants and inter alia may be situated in membranal phospholipids. Lipoxygenation causes the production of free radicals such as the superoxide, fatty acid, and peroxy species. Cytokinin (CK) lowers LOX and superoxide dismutase activities significantly in senescing foliage and is mimicked by the endogenous lipid antioxidant, α-tocopherol (vitamin E), in its chlorophyll-retaining and LOX-lowering effects. Further experimentation indicated that CK interaction with free radicals may occur in two ways, (i) CK may act as a direct free radical scavenger by virtue of the fact that the hydrogens of the α-carbon atom in the amine bond can be extracted, resulting in the formation of an amide: [Formula: see text][Formula: see text] (this mechanism may also, in part, explain polyamine effects), (ii) CK may serve as an incipient preventative of free radical formation by inhibiting oxidation of plant purine compounds, which at certain stages of breakdown release superoxide and hydroxyl free radicals. This effect is probably associated with a lowering of substrate affinity for xanthine oxidase. This assumption is further borne out by similar senescence-retarding effects of selective xanthine oxidase inhibitors such as allopurinol. These observations collectively indicate that prevention of free radical formation and (or) their direct scavenging should be included in the multifactorial antisencscence mode of action of cytokinin.

Effect of Melatonin on Feeding Intolerance and Incidence of Necrotizing Enterocolitis in Preterm Infants

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Hisham A Awad ◽  
Ola G El-Farghali ◽  
Hebatallah A Shaaban ◽  
Mona M El-Gammall
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Preterm Infants ◽  
Necrotizing Enterocolitis ◽  
Free Radical Scavenger ◽  
Preterm Neonates ◽  
Radical Scavenger ◽  
Feeding Intolerance ◽  
Traditional Treatment ◽  
Group I

Abstract Background Necrotizing enterocolitis (NEC) is one of the most dangerous gastrointestinal diseases that affects neonates especially preterm neonates. It is considered one of the oxygen radical diseases of neonatology as it is attributed to accumulation of reactive oxygen species (ROS) and free radicals leading to cellular oxidative damage. Melatonin proved to be an effective antioxidant and free radical scavenger with no documented side effects. Objective We aimed to evaluate the efficacy and safety of melatonin as adjuvant therapy in feeding intolerance and prophylaxis against NEC. Methods This was an interventional trial conducted on 90 preterm neonates with feeding intolerance. They were simply randomized to Group I that received melatonin treatment (n = 45) and Group II that received traditional treatment only (n = 45). Melatonin was administered at a total dose of 20 mg enterally in two divided doses of 10 mg each, 1 h apart. Tumor necrosis factor alpha (TNFα) level was assessed in patients 72 hours after starting treatment and both groups were observed for incidence of NEC, clinical improvement of feeding intolerance and time needed to reach full intake. Results Group I reported significantly less incidence of NEC in Group I treated with melatonin. Improved tolerance to feeds was observed in Group I resulting in earlier achievement of full enteral intake. Significantly higher levels of TNF alpha were found in Group II that received traditional treatment, indicative of higher level of oxidative stress and free radicals. Conclusion Melatonin in an effective and safe antioxidant and free radical scavenger associated with improvement of clinical and laboratory data in preterm infants with feeding intolerance and significantly less incidence of NEC.

A Review on the Use of Chitosan and its Derivatives as Radical Scavenger and Metal Ions Chelating Agent

2013 ◽  
Vol 734-737 ◽  
pp. 2218-2221 ◽  
Author(s):  
Hong Yan Dou ◽  
Xiao Qian Chen ◽  
Zong Quan Li
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Metal Ions ◽  
Paper Industry ◽  
Chelating Agent ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Reactive Groups

Chitosan has unique properties among biopolymers, especially due to the presence of several reactive groups, such as OH and NH2, which can react with many compounds. Chitosan and its derivatives are able to chelate metal ions, eliminate free radicals and resist oxidation. The development of chitosan and its derivatives used as metal ions chelating agent and free radical scavenger was overviewed. In addition, the application of chitosan and its derivatives and their potentiality in paper industry was prospected.

scholarly journals Dimeric Histidine as a Novel Free Radical Scavenger Alleviates Non-Alcoholic Liver Injury

Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1529
Author(s):  
Zizhen Zhao ◽  
Chen Fu ◽  
Yuping Zhang ◽  
Ailing Fu
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Liver Injury ◽  
High Fat Diet ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Common Disease ◽  
Alcoholic Liver Injury ◽  
High Fat ◽  
Free Radical Damage

Non-alcoholic liver injury (NLI) is a common disease worldwide. Since free radical damage in the liver is a crucial initiator leading to diseases, scavenging excess free radicals has become an essential therapeutic strategy. To enhance the antioxidant capacity of histidine, we synthesized a protonated dimeric histidine, H-bihistidine, and investigated its anti-free radical potential in several free-radical-induced NLI. Results showed that H-bihistidine could strongly scavenge free radicals caused by H2O2, fatty acid, and CCl4, respectively, and recover cell viability in cultured hepatocytes. In the animal model of nonalcoholic fatty liver injury caused by high-fat diet, H-bihistidine reduced the contents of transaminases and lipids in serum, eliminated the liver’s fat accumulation, and decreased the oxidative damage. Moreover, H-bihistidine could rescue CCl4-induced liver injury and recover energy supply through scavenging free radicals. Moreover, liver fibrosis prepared by high-fat diet and CCl4 administration was significantly alleviated after H-bihistidine treatment. This study suggests a novel nonenzymatic free radical scavenger against NLI and, potentially, other free-radical-induced diseases.

OPTIMASI KONDISI EKSTRAKSI SENYAWA AKTIF ANTIOKSIDAN DARI BIJI ANGGUR

2019 ◽  
Vol 3 (2) ◽  
pp. 35
Author(s):  
Kartini Kartini ◽  
Azminah Azminah
Keyword(s):  
Free Radical ◽  
Optimum Condition ◽  
Active Compound ◽  
Grape Seed ◽  
Free Radical Scavenger ◽  
Water Bath ◽  
Radical Scavenger ◽  
Optimum Conditions ◽  
Ethanolic Solution ◽  
Reduced Pressure

In order to prepare standardized extract, optimization of extraction conditions of grape seed has been done. These conditions are type of menstrum (50, 70 and 96% of ethanolic solution), length of extraction (1, 2 and 4 hours) also method of evaporation (reduced pressure and opened air). Activity on free radical scavenger used as parameters to determine optimum conditions. Based on EC50 (concentration which scavenge 50% amount of free radical) can be concluded that optimum condition for extracting antioxidant active compound from grape seed are 70% ethanolic solution as menstrum, length of extraction 1 hour and evaporation on opened air use water bath.

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