scholarly journals The Hyperfine Coupling Radical Pair Mechanism of Biological Effects on Weak Magnetic Fields

2019 ◽  
Vol 6 (1) ◽  
pp. 1-8
Author(s):  
Jin-Hua Ouyang
Keyword(s):  
Magnetic Fields ◽  
Hyperfine Coupling ◽  
Radical Pair ◽  
Biological Effects ◽  
Radical Pair Mechanism ◽  
Weak Magnetic Fields

scholarly journals Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs

2018 ◽  
Author(s):  
P. J. Hore
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Upper Bound ◽  
Prolonged Exposure ◽  
Radical Pair ◽  
Biological Effects ◽  
Radical Pair Mechanism ◽  
Childhood Leukaemia ◽  
Radical Pairs ◽  
Increased Risk

AbstractProlonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.

scholarly journals Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
PJ Hore
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Upper Bound ◽  
Prolonged Exposure ◽  
Radical Pair ◽  
Biological Effects ◽  
Radical Pair Mechanism ◽  
Childhood Leukaemia ◽  
Radical Pairs ◽  
Increased Risk

Prolonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.

Time-resolved studies of radical pairs

2009 ◽  
Vol 37 (2) ◽  
pp. 358-362 ◽  
Author(s):  
Jonathan R. Woodward ◽  
Timothy J. Foster ◽  
Alex R. Jones ◽  
Adrian T. Salaoru ◽  
Nigel S. Scrutton
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Chemical Reactions ◽  
Radical Pair ◽  
Radical Pair Mechanism ◽  
Magnetic Field Effects ◽  
Radical Pairs ◽  
Time Resolved ◽  
Field Effects ◽  
Field Sensitivity

The effect of magnetic fields on chemical reactions through the RP (radical pair) mechanism is well established, but there are few examples, in the literature, of biological reactions that proceed through RP intermediates and show magnetic field-sensitivity. The present and future relevance of magnetic field effects in biological reactions is discussed.

scholarly journals Magnetic field effects as a result of the radical pair mechanism are unlikely in redox enzymes

2015 ◽  
Vol 12 (103) ◽  
pp. 20141155 ◽  
Author(s):  
Hanan L. Messiha ◽  
Thanyaporn Wongnate ◽  
Pimchai Chaiyen ◽  
Alex R. Jones ◽  
Nigel S. Scrutton
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Radical Pair ◽  
Radical Pair Mechanism ◽  
Magnetic Field Effects ◽  
Experimental Conditions ◽  
Flow Measurements ◽  
Field Sensitivity ◽  
Biochemical Systems ◽  
The Magnetic Field

Environmental exposure to electromagnetic fields is potentially carcinogenic. The radical pair mechanism is considered the most feasible mechanism of interaction between weak magnetic fields encountered in our environment and biochemical systems. Radicals are abundant in biology, both as free radicals and reaction intermediates in enzyme mechanisms. The catalytic cycles of some flavin-dependent enzymes are either known or potentially involve radical pairs. Here, we have investigated the magnetic field sensitivity of a number of flavoenzymes with important cellular roles. We also investigated the magnetic field sensitivity of a model system involving stepwise reduction of a flavin analogue by a nicotinamide analogue—a reaction known to proceed via a radical pair. Under the experimental conditions used, magnetic field sensitivity was not observed in the reaction kinetics from stopped-flow measurements in any of the systems studied. Although widely implicated in radical pair chemistry, we conclude that thermally driven, flavoenzyme-catalysed reactions are unlikely to be influenced by exposure to external magnetic fields.

Influence of Dipolar Interactions on Radical Pair Recombination Reactions Subject to Weak Magnetic Fields

2005 ◽  
Vol 109 (5) ◽  
pp. 869-873 ◽  
Author(s):  
Anthony R. O'Dea ◽  
Ailsa F. Curtis ◽  
Nicholas J. B. Green ◽  
Christiane R. Timmel ◽  
P. J. Hore
Keyword(s):  
Magnetic Fields ◽  
Radical Pair ◽  
Dipolar Interactions ◽  
Weak Magnetic Fields ◽  
Recombination Reactions

scholarly journals Weak magnetic fields alter stem cell–mediated growth

2019 ◽  
Vol 5 (1) ◽  
pp. eaau7201 ◽  
Author(s):  
Alanna V. Van Huizen ◽  
Jacob M. Morton ◽  
Luke J. Kinsey ◽  
Donald G. Von Kannon ◽  
Marwa A. Saad ◽  
...  
Keyword(s):  
Stem Cell ◽  
Magnetic Fields ◽  
Biological Effects ◽  
Reaction Rates ◽  
Hsp70 Expression ◽  
Planarian Regeneration ◽  
Weak Magnetic Fields ◽  
Ros Accumulation ◽  
Geomagnetic Fields

Biological systems are constantly exposed to electromagnetic fields (EMFs) in the form of natural geomagnetic fields and EMFs emitted from technology. While strong magnetic fields are known to change chemical reaction rates and free radical concentrations, the debate remains about whether static weak magnetic fields (WMFs; <1 mT) also produce biological effects. Using the planarian regeneration model, we show that WMFs altered stem cell proliferation and subsequent differentiation via changes in reactive oxygen species (ROS) accumulation and downstream heat shock protein 70 (Hsp70) expression. These data reveal that on the basis of field strength, WMF exposure can increase or decrease new tissue formation in vivo, suggesting WMFs as a potential therapeutic tool to manipulate mitotic activity.

scholarly journals Electric Relaxation Processes in Lipid-Bilayers after Exposure to Weak Magnetic Pulses

2001 ◽  
Vol 56 (9-10) ◽  
pp. 831-837 ◽  
Author(s):  
Alexander Pazur
Keyword(s):  
Magnetic Fields ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Magnetic Particles ◽  
Biological Effects ◽  
Electrical Conductance ◽  
Relaxation Processes ◽  
Magnetic Pulse ◽  
Frequency Spectra ◽  
Weak Magnetic Fields

AbstractBiological effects of weak magnetic fields are widespread, but poorly understood. Besides magnetic particles, which have been shown to be involved in only few cases, membranes are discussed as the site of perception. However, the mechanism is unknown. We have subjected pure lipid membranes to weak magnetic pulses, and found, that their electric properties are modified.Black lipid membranes were prepared from purified asolectin on a teflon septum separating electrically the two chambers of a teflon cuvette, using the technique of Mueller et al. (1962). Single magnetic pulses were applied for 10 μs, whose intensity could be varied from 0 to 100 G (0 to 10 mT) at the membrane. Directly after the pulse decay, the conductance of the bilayers was scanned with 10 periods of a 1 kHz triangle alternating voltage (eg. a measurement time window of 10 ms). Frequency spectra of the bilayer current rose by a frequency dependent factor ≤ 2 in a broad region around 80 kHz, when the amplitude of the preceding magnetic pulse was increased from 0 to 100 G. The data show, that weak magnetic fields can significantly change the electrical conductance of lipid films. The relaxation of electrons in a two-dimensional quantum state (“quantum hollow”) will be discussed as a possible origin of these effects.

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