• hydrogen
  • Polyunsaturated fats and their breakdown products-aldehydes, prostaglandins, isoprostanes, hydrocarbons, and free radicals-and carbon monoxide, nitric oxide, nitrite, and hydrogen peroxide are increased in the breath by most stresses. (functionalps.com)
  • 4-6 Among them, the 3 superoxide dismutase (SOD) isoforms, the cytosolic copper zinc SOD (CuZnSOD, SOD-1), mitochondrial manganese SOD (MnSOD, SOD-2), and extracellular SOD (EC-SOD, SOD-3), have evolved as the key enzymatic defense system for converting O 2 − to hydrogen peroxide (H 2 O 2 ) and molecular oxygen (O 2 ). (ahajournals.org)
  • The initial aqueous solution contains hydrogen peroxide, an iodate, divalent manganese (Mn2+) as catalyst, a strong chemically unreactive acid (sulphuric acid (H2SO4) or perchloric acid (HClO4) are good), and an organic compound with an active ("enolic") hydrogen atom attached to carbon which will slowly reduce free iodine (I2) to iodide (I−). (Malonic acid (CH2(COOH)2) is excellent for that purpose. (wikipedia.org)
  • The bromide source can be sodium bromide, hydrogen bromide or tetrabromoethane where bromine functions as a regenerative source of free radicals. (wikipedia.org)
  • electron
  • investigated the consequences of NO regulation of mitochondrial activity in vascular endothelial cells, which are highly glycolytic and have abundant NO. Analysis of the effects of inhibitors of mitochondrial electron transport or glycolysis at various oxygen concentrations indicated that ATP production in human umbilical vein endothelial cells (HUVECs) depended more on glycolysis than it did on mitochondrial respiration. (sciencemag.org)
  • The oxygen that enters the body during exercise loses an electron and turns into free radicals inside the body. (ohsheglows.com)
  • A free radical is any atom or molecule that has a single unpaired electron in an outer shell. (wikipedia.org)
  • Free radicals, which contain only a single electron in any orbital, are usually unstable toward losing or picking up an extra electron, so that all electrons in the atom or molecule will be paired. (wikipedia.org)
  • Note that the unpaired electron does not imply charge - free radicals can be positively charged, negatively charged, or neutral. (wikipedia.org)
  • Damage occurs when the free radical encounters another molecule and seeks to find another electron to pair its unpaired electron. (wikipedia.org)
  • The free radical often pulls an electron off a neighboring molecule, causing the affected molecule to become a free radical itself. (wikipedia.org)
  • The new free radical can then pull an electron off the next molecule, and a chemical chain reaction of radical production occurs. (wikipedia.org)
  • The free radicals produced in such reactions often terminate by removing an electron from a molecule which becomes changed or cannot function without it, especially in biology. (wikipedia.org)
  • Firstly, as revealed by computational chemistry studies, the unpaired electron is stabilized through delocalization by the aromatic ring of tyrosine and the cross-linked cysteine sulfur, with the oxygen atom of Tyr272 possessing high unpaired electron density. (wikipedia.org)
  • He discovered a way to measure very slow rotational diffusion of proteins, and also introduced the EPR pulse technique known as saturation recovery for the measurement of electron spin lattice relaxation times of free radicals and spin labels in the fluid phase. (wikipedia.org)
  • oxidation
  • Moreover, the formation of cross-linking thioether bond is believed to lower the oxidation potential of Tyr272 phenoxide, making this phenoxyl more easily oxidized to form the radical in post-translational modification. (wikipedia.org)
  • In the Amoco process, terephthalic acid is produced by oxidation of p-xylene by oxygen in air: The process uses a cobalt-manganese-bromide catalyst. (wikipedia.org)
  • For example, the presence of racemic 9-HODE and 9-EE-HODE mixtures reflects free radical oxidation of linoleic acid whereas the presence of racemic 10-hydroxy-8E,12Z-octadecadienoic acid and 12-hydroxy-9Z-13-E-octadecadienoic acid reflects singlet oxygen attack on linoleic acid. (wikipedia.org)
  • radiation
  • Two sources inspired Harman: 1) the rate of living theory, which holds that lifespan is an inverse function of metabolic rate which in turn is proportional to oxygen consumption, and 2) Rebbeca Gershman's observation that hyperbaric oxygen toxicity and radiation toxicity could be explained by the same underlying phenomenon: oxygen free radicals. (wikipedia.org)
  • ischemia
  • Increased levels of free fatty acids also impair glucose metabolism which is the preferred myocardial substrate during periods of ischemia [ 16 ]. (hindawi.com)
  • Animal studies suggest the theoretical benefits to humans likely arise from altering the inflammatory response to ischemia, decreasing oxygen consumption in the brain, and reducing free radical formation in ischemic tissue. (ems1.com)
  • Myocardium
  • In the nonischemic myocardium, the primary energy substrate is free fatty acids [ 16 ]. (hindawi.com)
  • In the nondiabetic ischemic myocardium, the change from the oxidative metabolism of free fatty acids to that of glucose is protective since it allows the ischemic myocardium to more efficiently utilize oxygen to generate the ATP necessary to preserve cellular transport systems and prevent cell death. (hindawi.com)
  • impair
  • Thus, in the intact awake animal postischemic myocardial contractile dysfunction was not associated with decreased myocardial oxygen consumption and did not impair the normal relation between coronary blood flow and myocardial oxygen utilization. (biomedsearch.com)
  • decrease
  • Despite this decrease in contractile function, left anterior descending artery flow (19.6 +/- 2.6 vs. 18.4 +/- 3.0 ml/min), myocardial blood flow and the transmural distribution of flow measured with microspheres, and regional myocardial oxygen consumption were unchanged. (biomedsearch.com)
  • carbon
  • The basic control of blood flow in the brain is the result of the relaxation of the wall of blood vessels in the presence of carbon dioxide, which is produced in proportion to the rate at which oxygen and glucose are being metabolically combined by active cells. (functionalps.com)
  • solvent
  • Secondly, the indole ring of a tryptophan (Trp290) lies above and parallel to Tyrosine-Cysteine, behaving like a shield protecting the radical from the external solvent environment. (wikipedia.org)
  • In this process, acetic acid is the solvent and oxygen from compressed air is the oxidant. (wikipedia.org)
  • mixtures
  • In the presence of starch the number of oscillations are higher and the period times are longer compared to the starch-free mixtures. (wikipedia.org)
  • It was also found that the iodine consumption segment within one period of oscillation is also significantly longer in the starch containing mixtures. (wikipedia.org)
  • Pure oxygen cannot be used in the traditional system due to hazards of flammable organic-O2 mixtures. (wikipedia.org)
  • antioxidants
  • Rather, the activation of AMPK at 3% oxygen was stimulated by ROS and was inhibited by antioxidants. (sciencemag.org)
  • Over-consumption of exogenous antioxidants could thus lead to the state of antioxidative stress, where antioxidants might attenuate or block the adaptive stress responses. (wikipedia.org)
  • The concept of antioxidative stress may best be described by excessive or detrimental nutritional consumption of a diet rich in antioxidants, unbalancing the immune systems' pathogenic response processes. (wikipedia.org)
  • This is generally due to the biological effects of antioxidants being misunderstood in popular culture, focusing only on their beneficial qualities to reduce ROS to prevent excessive free-radicals which may otherwise lead to well-known disease conditions. (wikipedia.org)
  • Several complex biological free-radical collection systems already exist for the purpose of scavenging, which normally, do not require augmentation by supplementation of antioxidants to function nominally. (wikipedia.org)
  • metabolism
  • This strategy of combining hypofractionated radiotherapy with metabolic reprogramming to inhibit anaerobic metabolism may increase the efficacy of HD-SFRT through increased oxygen consumption and complementary killing of radiosensitive and hypoxic, radioresistant cells. (biomedcentral.com)
  • reaction
  • The chain reaction caused by free radicals can lead to cross-linking of atomic structures. (wikipedia.org)
  • In cases where the free radical-induced chain reaction involves base pair molecules in a strand of DNA, the DNA can become cross-linked. (wikipedia.org)
  • Bubbles of free oxygen are evolved throughout, and in most cases, the final state is rich in free iodine As noted above, the reaction will oscillate in a fairly wide range of initial concentrations of the reactants. (wikipedia.org)
  • glycolysis
  • The goal of this study was to investigate the effect of metabolic-targeting through HIF-1α inhibition and the associated changes in glycolysis, oxygen consumption and response on the efficacy of high-dose single-fraction radiotherapy (HD-SFRT). (biomedcentral.com)
  • body
  • In addition, the technique of saturation recovery was further developed across most of this range of microwave frequencies, which led to an extensive body of work on transport and cellular consumption of oxygen. (wikipedia.org)
  • Cells
  • Stabilizes biomembranes, i.e. membrane structures of blood cells - erythrocytes and thrombocytes during their haemolysis or mechanical injury accompanied by the formation of free radicals. (wikipedia.org)
  • generator
  • This suggests that the free radical generator of Complex I is located after the ferricyanide reduction site, between the ethoxyformic and the rotenone-sensitive sites. (nih.gov)
  • So far, AAPH (2,2'-azobis(2-amidino-propane) dihydrochloride) is the sole free-radical generator used. (wikipedia.org)
  • compounds
  • The assay measures the oxidative degradation of the fluorescent molecule (either beta-phycoerythrin or fluorescein) after being mixed with free radical generators such as azo-initiator compounds. (wikipedia.org)
  • Segment
  • Left anterior descending coronary artery blood flow and oxygen extraction, aortic and left ventricular pressures, and regional myocardial segment shortening were determined. (biomedsearch.com)