The world as viewed by and with unpaired electrons

Eaton, Sandra S.; Eaton, Gareth R.

doi:10.1016/j.jmr.2012.07.025

Cited by 20 publications

(26 citation statements)

References 215 publications

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“…They are relevant to electron paramagnetic resonance (EPR) imaging which is considered to be a potential contributor to the understanding of the in vivo biochemistry particularly in the study of free radicals (83).…”

Section: Discussionmentioning

confidence: 99%

Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond

Winter

Niendorf

2016

Magn Reson Mater Phy

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Materials and MethodsElectromagnetic field simulations (EMF) are performed in phantoms with average tissue simulants for dipole antennae using discrete frequencies (300MHz (7.0T) to 3GHz (70.0T)).To advance to a human setup EMF simulations are conducted in anatomical human voxel models of the human head using a 20-element dipole array operating at 1 GHz. ResultsOur results demonstrate that transmission fields suitable for 1 H MR of the human brain can be achieved at 1GHz. An increase in transmit channel density around the human head helps to enhance B1 + in the center of the brain. The calculated relative increase in specific absorption rate (SAR) at 23.5T vs. 7.0T was below 1.4 (in-phase phase setting) and 2.7 (circular polarized phase setting) for the dipole antennae array. ConclusionThe benefits of multi-channel dipole antennae at higher frequencies render MR at 23.5Tfeasible from an electrodynamic standpoint. This very preliminary finding opens the door on further explorations that might be catalyzed into a 20 Tesla class human MR system.2

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Section: Discussionmentioning

confidence: 99%

Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond

Winter

Niendorf

2016

Magn Reson Mater Phy

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“…Electron paramagnetic resonance (EPR) detection has been recognized as one of the most powerful techniques for directly and quantitatively measuring the ROS in biological systems [10][11][12][13][14][15]. As a conventional EPR methodology for ROS detection in vitro, it has been a standard practice to use a cell suspension after the detachment procedure and a thin quartz tube to measure the reactive oxygen and nitrogen species in the cells [16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

In Situ EPR Detection of Reactive Oxygen Species in Adherent Cells Using Polylysine-Coated Glass Plate

Ando

Yonamoto

2015

Appl Magn Reson

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In conventional electron paramagnetic resonance (EPR) experiments, it is a common procedure to use a cell suspension after detachment to measure reactive oxygen species (ROS) generated in the cell. However, to elucidate redox signaling transduction between the cells, the sample should be under cell culture conditions. Here, we propose an in situ EPR detection methodology of ROS produced in adherent cells. A quartz glass plate was coated with poly-L-lysine (PLL) to improve the adhesion efficiency of cultured cells. Using mouse fibroblasts and human malignant epithelial cells (HeLa) on the glass sheet (approximately 6.5 9 10 4 adherent cells per sheet), remarkable increases in the relative EPR signal intensities of spin adducts related to superoxide radicals were observed 1 h after addition of a redox-active compound (pyocyanin) and a spin trap to the culture medium. There was no disturbing effect on the EPR signals with the PLL-coated glass plate alone. The intensity of EPR signals in HeLa cells without exogenous pyocyanin was statistically significantly higher than that of the control, implying intrinsically larger amounts of ROS in cancer cells than those in non-malignant ones. Moreover, an optically transparent holder for supporting the cell-adhered glass substrate enabled both EPR detection of ROS and microscopic observation, where more than 88 % of cell viability was maintained. These findings demonstrated that the proposed in situ EPR methodology would be useful for measuring ROS generated under cell culture conditions.

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“…The most modern physical methods include electron spin resonance (ESR) spectroscopy. Its principle involves measuring the absorption of electromagnetic (microwave) radiation by paramagnetic substances and/or the interaction of electromagnetic radiation with the intrinsic magnetic moment of electrons arising from their spin . ESR determination of antioxidant properties of beer/wort (endogenous antioxidative potential – EAP) is usually carried out by measuring the time required for the formation of free radicals in heated, force‐oxidized samples .…”

Section: Introductionmentioning

confidence: 99%

Relationship of iso-α-acid content and endogenous antioxidative potential during storage of lager beer

et al. 2014

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One of the critical issues regarding the quality of beer is the change in its chemical composition that occurs during storage. Decomposition of iso-α-acids results in an undesirable decrease in bitterness as well as a deterioration in the sensory profile of the beer. These changes are caused by the susceptibility of iso-α-acids to degradation owing to the influence of reactive oxygen species and light. The aim of this study was to investigate the influence of storage conditions (temperature, light) on the degradation of iso-α-acids during aging, with the main focus on monitoring the relationship between the turnover of iso-α-acids, the sulphur dioxide content and the antioxidative potential of stored beer as measured by electron spin resonance spectroscopy. In agreement with previous investigations, a significant decrease in the content of bitter compounds (up to 18 % relative to the original level, depending on storage conditions) was observed. A significant decrease in the antioxidant potential of beer was recorded simultaneously and the data confirmed a strong correlation between these parameters. The decline in beer bitterness could become a marker for estimating oxidative damage during storage.

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The world as viewed by and with unpaired electrons

Cited by 20 publications

References 215 publications

Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond

Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond

In Situ EPR Detection of Reactive Oxygen Species in Adherent Cells Using Polylysine-Coated Glass Plate

Relationship of iso-α-acid content and endogenous antioxidative potential during storage of lager beer

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