Exploration of the biological effects of transition metal ions in acupuncture points is essential to clarify the functional mechanism of acupuncture treatment. Here we show that in the SP6 acupuncture point (Sanyinjiao) the Fe ions are in a high-spin state of approximately t(2g)(4.5)e(g)(1.5) in an Fe-N(O) octahedral crystal field. The Fe K-edge synchrotron radiation X-ray absorption fine structure results reveal that the Fe-N and Fe-O bond lengths in the SP6 acupuncture point are 2.05 and 2.13 angstrom, respectively, and are 0.05-0.10 angstrom longer than those in the surrounding tissue. The distorted atomic structure reduces the octahedral symmetry and weakens the crystal field around the Fe ions by approximately 0.3 eV, leading to the high-spin configuration of the Fe ions, which is favorable for strengthening the magnetotransport and oxygen transportation properties in the acupuncture point by the enhanced spin coherence. This finding might provide some insight into the microscopic effect of the atomic and electronic interactions of transition metal ions in the acupuncture point.
[1]Fudan Univ, State Key Lab Surface Phys, Synchrotron Radiat Res Ctr, Shanghai 200433, Peoples R China;
[2]Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China;
[3]Yancheng Teachers Univ, Sch Phys & Elect Engn, Yancheng 224007, Jiangsu, Peoples R China;
[4]Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei 230029, Anhui, Peoples R China;
[5]Natl Inst Adv Ind Sci & Technol, Tsukuba Cent 2, Tsukuba, Ibaraki 3058568, Japan
(8.0+极速模式)