Publications - Hiroshi Hirata, Ph.D.

Peer-Reviewed Scientific Journals

  1. C.-U. Koo, J.-I. Park, J. Oh, K. Choi, J. Yoon, H. Hirata, and S.-J. Ye. Frequency-fixed motion compensation system for in-vivo electron paramagnetic resonance tooth dosimetry. Journal of Magnetic Resonance, Vol. 353, article no. 107520 (2023). DOI: 10.1016/j.jmr.2023.107520, published online 9 July 2023. https://doi.org/10.1016/j.jmr.2023.107520
  2. R. Nakaoka, K. Kato, K. Yamamoto, H. Yasui, S. Matsumoto, I. A. Kirilyuk, V. V. Khramtsov, O. Inanami, and H. Hirata. Electron paramagnetic resonance implemented with multiple harmonic detections successfully maps extracellular pH in vivo. Analytical Chemistry, Vol. 95, No. 8, pp. 3940-3950 (2023). DOI: 10.1021/acs.analchem.2c03194, published online 1 February 2023. https://doi.org/10.1021/acs.analchem.2c03194 (Open Access)
  3. R. Sato, A. Utagawa, K. Fushimi, F. Li, T. Isono, K. Tajima, T. Satoh, S. Sato, H. Hirata, Y. Kikkawa, and T. Yamamoto. Molecular weight-dependent oxidation and optoelectronic properties of defect-free macrocyclic poly(3-hexylthiophene). Polymers, Vol. 15, No. 3, article no. 666 (2023). DOI: 10.3390/polym15030666, published online 28 January 2023. https://doi.org/10.3390/polym15030666 (Open Access)
  4. K. Choi, C.-U. Koo, J.-H. Oh, J.-I. Park, H. Hirata, and S.-J. Ye. Development of electron paramagnetic resonance magnet system for in vivo tooth dosimetry. Concepts in Magnetic Resonance Part B, Magnetic Resonance Engineering, Vol. 2022, article no. 7332324 (2022). DOI: 10.1155/2022/7332324, published online 27 May 2022. https://doi.org/10.1155/2022/7332324 (Open Access)
  5. F. Cheng, T. Shibata, Y. Aoki, and H. Hirata. A 2.0-GHz compact ESR spectrometer for monitoring automobile lubrication oil degradation. Journal of Magnetic Resonance, Vol. 332, article no. 107081 (2021). DOI: 10.1016/j.jmr.2021.107081, published online 1 October 2021. https://doi.org/10.1016/j.jmr.2021.107081
  6. H. Hirata and H. M. Swartz. RF/microwave resonators for clinical and preclinical EPR applications: Current status and challenges. Applied Magnetic Resonance, Vol. 53, No. 1, pp. 3167-191 (2022). DOI: 10.1007/s00723-021-01413-3, published online 16 August 2021. https://doi.org/10.1007/s00723-021-01413-3
  7. Y. Nakai, I. Yamaguchi, H. Hirata, H. M. Swartz, A. B. Flood, B. B. Williams, W. Schreiber, and M. Miyake. Effects of UV on L-band in vivo EPR dosimetry using tooth enamel. Applied Magnetic Resonance, Vol. 53, No. 1, pp. 305-318 (2022). DOI: 10.1007/s00723-021-01340-3, published online 10 July 2021. https://doi.org/10.1007/s00723-021-01340-3
  8. N. J. Stewart, T. Sato, N. Taketa, T. Hashimoto, H. Hirata, and S. Matsumoto. Hyperpolarized 13C MRI as a tool for imaging tissue redox status. Antioxidants and Redox Signaling, Vol. 36, Nos. 1-3, pp. 81-94 (2022). DOI: 10.1089/ars.2021.0139, published online 4 July 2021. https://doi.org/10.1089/ars.2021.0139 (Open Access)
  9. D. A. Komarov, A. Samouilov, H. Hirata, and J. L. Zweier. High fidelity triangular sweep of the magnetic field for millisecond range fast scan EPR imaging. Journal of Magnetic Resonance, Vol. 329, article no. 107024 (2021). DOI: 10.1016/j.jmr.2021.107024, published online 9 June 2021. https://doi.org/10.1016/j.jmr.2021.107024
  10. K. Kimura, N. Iguchi, H. Nakano, H. Yasui, S. Matsumoto, O. Inanami, and H. Hirata. Redox-sensitive mapping of a mouse tumor model using sparse projection sampling of electron paramagnetic resonance. Antioxidants and Redox Signaling, Vol. 36, Nos. 1-3, pp. 57-69 (2022). DOI: 10.1089/ars.2021.0003, published online 13 April 2021. https://doi.org/10.1089/ars.2021.0003 (Open Access)
  11. N. J. Stewart, H. Nakano, S. Sugai, M. Tomohiro, Y. Kase, Y. Uchio, T. Yamaguchi, Y. Matsuo, T. Naganuma, N. Takeda, I. Nishimura, H. Hirata, T. Hashimoto, and S. Matsumoto. Hyperpolarized 13C MRI of fumarate metabolism by parahydrogen-induced polarization: A proof-of-concept in vivo study. ChemPhysChem (2021). DOI: 10.1002/cphc.202001038, published online 16 February 2021. https://doi.org/10.1002/cphc.202001038 (Open Access)
  12. J.-I. Park, K. Choi, C.-U. Koo, J. Oh, H. Hirata, H. M. Swartz, and S.-J. Ye. Dependence of radiation-induced signals on geometry of tooth enamel using a 1.15 GHz electron paramagnetic resonance spectrometer: Improvement of dosimetric accuracy. Health Physics, Vol. 120, No. 2, pp. 152-162 (2021). DOI: 10.1097/HP.0000000000001292, published online 15 July 2020. https://doi.org/10.1097/HP.0000000000001292
  13. A. Taguchi, S. DeVience, B. Driesschaert, V. V. Khramtsov, and H. Hirata. In vitro simultaneous mapping of the partial pressure of oxygen, pH and inorganic phosphate using electron paramagnetic resonance. Analyst, Vol. 145, no. 9, pp. 3236-3244 (2020). DOI: 10.1039/D0AN00168F, published online 26 February 2020. Selected as Outside Back Cover. https://doi.org/10.1039/D0AN00168F
  14. R. Nakaoka and H. Hirata, Noise characteristics of a 750-MHz electronically tunable resonator for electron paramagnetic resonance spectroscopy, AIP Advances, Vol. 9, No. 7, article no. 075312 (2019) (7 pages). DOI: 10.1063/1.5099381, published online 18 July 2019. https://doi.org/10.1063/1.5099381 (Open Access)
  15. T. Yokoyama, A. Taguchi, H. Kubota, N. J. Stewart, S. Matsumoto, I. A. Kirilyuk, and H. Hirata, Simultaneous T2* mapping of 14N- and 15N-labeled dicarboxy-PROXYLs using CW-EPR-based single-point imaging, Journal of Magnetic Resonance, Vol. 305, pp. 122-130 (2019). DOI: 10.1016/j.jmr.2019.06.012, published online 26 June 2019. http://doi.org/10.1016/j.jmr.2019.06.012
  16. D. A. Komarov, Y. Ichikawa, K. Yamamoto, N. J. Stewart, S. Matsumoto, H. Yasui, I. A. Kirilyuk, V. V. Khramtsov, O. Inanami, and H. Hirata. In vivo extracellular pH mapping of tumors using electron paramagnetic resonance. Analytical Chemistry, doi: 10.1021/acs.analchem.8b03328, published online 29 October 2018. [Selected as Supplementary Journal Cover] http://doi.org/10.1021/acs.analchem.8b03328
  17. R. Nakaoka, D. A. Komarov, S. Matsumoto, and H. Hirata. Impact of the characteristic impedance of coaxial lines on the sensitivity of a 750-MHz electronically tunable EPR resonator. Applied Magnetic Resonance, Vol. 49, No. 8, pp. 853-867 (2018). DOI: 10.1007/s00723-018-1001-6, published online 31 March 2018. http://doi.org/10.1007/s00723-018-1001-6
  18. H. Sato-Akaba, M. C. Emoto, H. Hirata, and H. G. Fujii, Design and testing of a 750 MHz CW-EPR digital console for small animal imaging, Journal of Magnetic Resonance, Vol. 284, pp. 48-58 (2017). DOI: 10.1016/j.jmr.2017.09.008, published online 20 September 2017. http://dx.doi.org/10.1016/j.jmr.2017.09.008
  19. T. Amida, R. Nakaoka, D. A. Komarov, K. Yamamoto, O. Inanami, S. Matsumoto, and H. Hirata, A 750-MHz electronically tunable resonator using microstrip line couplers for electron paramagnetic resonance imaging of a mouse tumor-bearing leg, IEEE Transactions on Biomedical Engineering, Vol. 65, No. 5, pp. 1124-1132 (2018). DOI: 10.1109/TBME.2017.2743232, published online 23 August 2017. http://dx.doi.org/10.1109/TBME.2017.2743232
  20. M. Umakoshi, I. Yamaguchi, H. Hirata, N. Kunugita, B. B. Williams, H. M. Swartz, and M. Miyake, In vivo electron paramagnetic resonance tooth dosimetry: Dependence of radiation-induced signal amplitude on the enamel thickness and surface area of ex vivo human teeth,Health Physics, Vol. 113, No. 4, pp. 262-270 (2017). DOI: 10.1097/HP.0000000000000698, published online 7 August 2017. http://dx.doi.org/10.1097/HP.0000000000000698 (Open Access)
  21. D. A. Komarov and H. Hirata, Fast backprojection-based reconstruction of spectral-spatial EPR images from projections with the constant sweep of a magnetic field, Journal of Magnetic Resonance, Vol. 281, pp. 44-50 (2017), published online 17 May 2017. http://dx.doi.org/10.1016/j.jmr.2017.05.005
  22. H. Kubota, D. A. Komarov, H. Yasui, S. Matsumoto, O. Inanami, I. A. Kirilyuk, V. V. Khramtsov, and H. Hirata, Feasibility of in vivo three-dimensional T2* mapping using dicarboxy-PROXYL and CW-EPR-based single-point imaging, Magnetic Resonance Materials in Physics, Biology and Medicine, Vol. 30, No. 3, pp. 291-298 (2017), published online 6 January 2017. http://dx.doi.org/10.1007/s10334-016-0606-8
  23. X. Wang, M. Emoto, Y. Miyake, K. Itto, S. Xu, H. Fujii, H. Hirata, H. Arimoto, Novel blood-brain-barrier-permeable spin probe for in vivo electron paramagnetic resonance imaging, Bioorganic & Medicinal Chemistry Letters, Vol. 26, No. 20, pp. 4947-4949 (2016), published online 6 September 2016. http://dx.doi.org/10.1016/j.bmcl.2016.09.010
  24. M. Miyake, Y. Nakai, I. Yamaguchi, H. Hirata, N. Kunugita, B. B. Williams, and H. M. Swartz, In-vivo radiation doeimstry using portable L band EPR: On-site measurement of volunteers in Fukushima prefecture, Japan, Radiation Protection Dosimetry, Vol. 172, No. 1-3, pp. 248-253 (2016), published online 13 August 2016. http://dx.doi.org/10.1093/rpd/ncw214
  25. A. Enomoto, K. Saito, S. Subramanian, M. C. Krishna, H. Hirata, and N. Devasahayam, Passive decoupling due to low Q-factors of four-channel coils in 300-MHz pulsed EPR imaging, Applied Magnetic Resonance, Vol. 46, No. 6, pp. 671-683 (2015), published online 26 March 2015. http://dx.doi.org/10.1007/s00723-015-0671-6
  26. W. Takahashi, Y. Miyake, and H. Hirata, Artifact suppression in electron paramagnetic resonance imaging of 14N- and 15N-labeled nitroxyl radicals with asymmetric absorption spectra, Journal of Magnetic Resonance, Vol. 247, pp. 31-37 (2014), published online 20 August 2014. http://dx.doi.org/10.1016/j.jmr.2014.08.001
  27. W. Takahashi, A. A. Bobko, I. Dhimitruka, H. Hirata, J. L. Zweier, A. Samouilov, and V. V. Khramtsov, Proton-electron double-resonance imaging of pH using phosphonated trityl probe, Applied Magnetic Resonance, Vol. 45, No. 9, pp. 817-826 (2014), published online 17 August 2014. http://dx.doi.org/10.1007/s00723-014-0570-2
  28. A. B. Flood, B. B. Williams, W. Schreiber, G. Du, V. A. Wood, M. M. Kmiec, S. V. Petryakov, E. Demidenko, H. M. Swartz, and the EPR Center Tooth Dosimetry Project Team. Advances in in vivo EPR tooth biodosimetry: Meeting the targets for initial triage following a large-social radiation event. Radiation Protection Dosimetry, Vol. 172, No. 1-3, pp. 72-80 (2016), doi: 10.1093/rpd/ncw165, published online 15 July 2016. (The EPR Center Tooth Dosimetry Project Team includes H. Hirata) http://dx.doi.org/10.1093/rpd/ncw165
  29. M. C. Emoto, H. Sato-Akaba, H. Hirata, and H. G. Fujii, Dynamic changes in the distribution and time-course of blood-brain barrier-permeable nitroxides in the mouse head with EPR imaging: Visualization of blood flow in a mouse model, Free Rdical Biology and Medicine, Vol. 74, pp. 222-228 (2014), published online 8 July 2014. http://dx.doi.org/10.1016/j.freeradbiomed.2014.06.026
  30. H. Sugawara, H. Hirata, S. Petryakov, P. Lesniewski, B. B. Williams, A. B. Flood, and H. M. Swartz, Design and evaluation of a 1.1-GHz surface coil resonator for electron paramagnetic resonance-based tooth dosimetry, IEEE Transactions on Biomedical Engineering, Vol. 61, No. 6, pp. 1894-1901 (2014), published online 6 March 2014. http://dx.doi.org/10.1109/TBME.2014.2310217
  31. X. Wang, M. Emoto, A. Sugimoto, Y. Miyake, K. Itto, M. Amasaka, S. Xu, H. Hirata, H. Fujii, and H. Arimoto, Synthesis of 15N-labeled 4-oxo-2,2,6,6-tetraethylpiperidine nitroxide for EPR brain imaging, Tetrahedron Letters, Vol. 55, No. 14, pp. 2146-2149 (2014), published online 25 February 2014. http://dx.doi.org/10.1016/j.tetlet.2014.02.063
  32. J. Goodwin, K. Yachi, M. Nagane, H. Yasui, Y. Miyake, O. Inanami, A. A. Bobko, V. V. Khramtsov, and H. Hirata, In vivo tumour extracellular pH monitoring using electron paramagnetic resonance: the effect of X-ray irradiation, NMR in Biomedicine, Vol. 27, No. 4, pp. 453-458 (2014), published online 28 January 2014. http://dx.doi.org/10.1002/nbm.3081
  33. A. Enomoto and H. Hirata, Parallel image-acquisition in continuous-wave electron paramagnetic resonance imaging with a surface coil array: Proof-of-concept experiments, Journal of Magnetic Resonance, Vol. 239, pp. 29-33 (2014), published online 12 December 2013.
  34. A. Enomoto, M. Emoto, H. Fujii, and H. Hirata, Four-channel surface coil array for sequential CW-EPR image acquisition, Journal of Magnetic Resonance, Vol. 234, pp. 21-29 (2013), published online 18 June 2013.
  35. A. Enomoto, H. Hirata, S. Matsumoto, K. Saito, S. Subramanian, M. C. Krishna, and N. Devasahayam, Four-channel surface coil array for 300-MHz pulsed EPR imaging: Proof-of-concept experiments, Magnetic Resonance in Medicine, Vol. 71, No. 2, pp. 853-858 (2014), published online 26 March 2013.
  36. T. Haga, H. Hirata, P. Lesniwski, K. M. Rychert, B. B. Williams, A. B. Flood, and H. M. Swartz, L-band surface-coil resonator with voltage-control impedance-matching for EPR tooth dosimetry, Concepts in Magnetic Resonance Part B Magnetic Resonance Engineering, Vol. 43B, No. 1, pp. 32-40 (2013), published online 25 February 2013.
  37. Y. Miyake, X. Wang, M. Amasaka, K. Itto, S. Xu, H. Arimoto, H. Fujii, and H.Hirata, Simultaneous imaging of an enantiomer pair by electron paramagnetic resonance using isotopic nitrogen labeling, Analytical Chemistry, Vol. 85, No. 2, pp. 985-990 (2013), published online 18 December 2012.
  38. H. Fujii, H. Sato-Akaba, M. Emoto, K. Itoh, Y. Ishihara, and H. Hirata, Noninvasive mapping of the redox status in septic mouse by in vivo electron paramagnetic resonance imaging, Magnetic Resonance Imaging, Vol. 31, No. 1, pp. 130-138 (2013), published online 20 August 2012.
  39. K. Nakagawa, Y. Ohba, B. Epel, and H. Hirata, A 9 GHz EPR imager for thin materials: application to surface detection, Journal of Oleo Science, Vol. 61, No. 8, pp. 451-456 (2012), published online 2 August 2012.
  40. S. Koda, J. Goodwin, V. V. Khramtsov, H. Fujii, and H. Hirata, Electron paramagnetic resonance-based pH mapping using spectral-spatial imaging of sequentially scanned spectra, Analytical Chemistry, Vol. 84, No. 8, pp. 3833-3837 (2012), published online 15 March 2012.
  41. M. Ohfuchi, J. Goodwin, H. Fujii, and H. Hirata, Three-dimensional EPR/NMR image co-registration using a MATLAB-based software, Concepts in Magnetic Resonance Part B Magnetic Resonance Engineering, Vol. 39B, No. 4, pp. 180-190 (2011), published online 28 October 2011.
  42. M. Emoto, F. Mito, T. Yamasaki, K. Yamada, H. Sato-Akaba, H. Hirata, and H. Fujii Three-dimensional EPR imaging of mouse head using novel ascorbic acid-resistive nitroxide probes, Free Radical Research, Vol. 45, No. 11&12, pp. 1325-1332 (2011), published online 5 September 2011.
  43. A. Enomoto and H. Hirata, Sequential CW-EPR image acquisition with 760-MHz surface coil array, Journal of Magnetic Resonance, Vol. 209, No. 2, pp. 244-249 (2011), published online 26 January 2011.
  44. A. Pawlak, R. Ito, H. Fujii, and H. Hirata, Simultaneous molecular imaging based on electron paramagnetic resonance of 14N- and 15N-labelled nitroxyl radicals, Chemical Communications, Vol. 47, No. 11, pp. 3245-3247 (2011), published online 27 January 2011.
  45. H. Fujii, H. Sato-Akaba, K. Kawanishi, and H. Hirata, Mapping of redox status in a brain-disease mouse model by three-dimensional EPR imaging, Magnetic Resonance in Medicine, Vol. 65, No. 1, pp. 295-303 (2011), published online 21 September 2010.
  46. H. Sato-Akaba, Y. Kuwahara, H. Fujii, and H. Hirata, Half-life mapping of nitroxyl radicals with three-dimensional electron paramagnetic resonance imaging at an interval of 3.6 seconds, Analytical Chemistry, Vol. 81, No. 17, pp. 7501-7506 (2009), published online 31 July 2009.
  47. Y. Ikebata, H. Sato-Akaba, T. Aoyama, H. Fujii, K. Itoh, and H. Hirata, Resolution-recovery for EPR imaging of free radical molecules in mice, Magnetic Resonance in Medicine, Vol. 62, No. 3, pp. 788-795 (2009), published online 21 July 2009.
  48. H. Sato-Akaba, H. Fujii, and H. Hirata, Improvement of temporal resolution for three-dimensional continuous-wave electron paramagnetic resonance imaging, Review of Scientific Instruments, Vol. 79, No. 12, article no. 123701 (2008) (7 pages), published online 1 December 2008.
  49. H. Sato-Akaba, H. Fujii, and H. Hirata, Development and testing of a CW-EPR apparatus for imaging of short-lifetime nitroxyl radicals in mouse head, Journal of Magnetic Resonance, Vol. 193, No. 2, pp. 191-198 (2008), published online 29 April 2008.
  50. H. Sato-Akaba, H. Abe, H. Fujii, and H. Hirata, Slice-selective images of free radicals in mice with modulated field gradient electron paramagnetic resonance (EPR) imaging, Magnetic Resonance in Medicine, Vol. 59, No. 4, pp. 885-890 (2008), published online 25 January 2008.
  51. H. Fujii, K. Sakata, Y. Katsumata, R. Sato, M. Kinouchi, M. Someya, S. Masunaga, M. Hareyama, H. M. Swartz, and H. Hirata, Tissue oxygenation in a murine SCC VII tumor after X-ray irradiation as determined by EPR spectroscopy, Radiotherapy and Oncology, Vol. 86, No. 3, pp. 354-360 (2008), published online 20 February 2008.
  52. S. Matsumoto, M. G. Espey, H. Utsumi, N. Devasahayam, K. Matsumoto, A. Matsumoto, H. Hirata, D. A. Wink, P. Kuppusamy, J. B. Mitchell, and M. C. Krishna, Dynamic Monitoring of Localized Tumor Oxygenation Changes by Radio Frequency Pulsed EPR in Conscious Mice, Magnetic Resonance in Medicine, Vol. 59, No. 3, pp. 619-625 (2008), published online 25 January 2008.
  53. H. Hirata, G. He, Y. Deng, I. Salikhov, S. Petryakov, and J. L. Zweier, A loop resonator for slice-selective in vivo EPR imaging in rats, Journal of Magnetic Resonance, Vol. 190, No. 1, pp. 124-134 (2008), published online 30 October 2007.
  54. H. Fujii, K. Itoh, R. P. Pandian, M. Sakata, P. Kuppusamy, and H. Hirata, Measurement of tissue oxygenation under oxidative stress by ESR/MRI dual system, Magnetic Resonance in Medical Sciences, Vol. 6, No. 2, pp. 83-89 (2007).
  55. H. Hirata and H. Fujii, Automatic matching control circuit based on phase-sensitive detection for in vivo CW-EPR spectroscopy, Measurement Science and Technology, Vol. 18, No. 5, pp. N27-N31 (2007), published online 3 April 2007.
  56. S. Matsumoto, K. Yamada, H. Hirata, K. Yasukawa, F. Hyodo, K. Ichikawa, and H. Utsumi, Advantageous application of surface coil to EPR irradiation in Overhauser-enhanced MRI, Magnetic Resonance in Medicine, Vol. 57, No. 4, pp. 806-811 (2007), published online 27 March 2007.
  57. R. Ahmad, B. Clymer, D. S. Vikram, Y. Deng, H. Hirata, J. L. Zweier, and P. Kuppusamy, Enhanced resolution for EPR imaging by two-step deblurring, Journal of Magnetic Resonance, Vol. 184, No. 2, pp. 246-257 (2007), published online 20 November 2006. [Selected as Journal Cover]
  58. Y. Kawada, H. Hirata, and H. Fujii, Use of multi-coil parallel-gap resonators for co-registration EPR/NMR imaging, Journal of Magnetic Resonance, Vol. 184, No. 1, pp. 29-38 (2007), published online 6 October 2006. [Selected as Journal Cover]
  59. H. Hirata, M. Wakana, H. Susaki, Feasibility study of superresolution continuous-wave electron paramagnetic resonance imaging, Applied Physics Letters, Vol. 88, No. 25, article no. 254103 (2006) (3 pages).
  60. K. Takeshita, C. Chi, H. Hirata, M. Ono, and T. Ozawa, In vivo generation of free radical in the skin of living mouse under ultraviolet light measured by L-band EPR spectroscopy, Free Radical Biology and Medicine, Vol. 40, No. 5, pp. 876-885 (2006).
  61. H. Hirata and H. Fujii, Free radicals in living systems: In vivo detection of bioradicals with EPR spectroscopy, Current Organic Chemistry, Vol. 10, No. 5, pp. 521-534 (2006).
  62. H. Hirata, T. Itoh, K. Hosokawa, Y. Deng, H. Susaki, Systematic approach to cutoff frequency selection in continuous-wave electron paramagnetic resonance imaging, Journal of Magnetic Resonance, Vol. 175, No. 2, pp. 177-184 (2005).
  63. S. Matsumoto, M. Nagai, K. Yamada, F. Hyodo, K. Yasukawa, M. Muraoka, H. Hirata, M. Ono, and H. Utsumi, A composit resonator assemble for EPR/NMR co-registration imaging, Concepts in Magnetic Resonance Part B Magnetic Resonance Engineering, Vol. 25B, No. 1, pp. 1-11 (2005).
  64. H. Hirata, H. Watanabe, M. Kumada, K. Itoh, and H. Fujii, Decoupling of automatic control systems in a continuous-wave electron paramagnetic resonance spectrometer for biomedical applications, NMR in Biomedicine, Vol. 17, No. 5, pp. 295-302 (2004).
  65. K. Takeshita, T. Takajo, H. Hirata, M. Ono, and H. Utsumi, In vivo Oxygen Radical Generation in the Skin of the Protoporphyria Model Mouse with Visible Light Exposure: An L-Band ESR Study, Journal of Investigative Dermatology, Vol. 122, No. 6, pp. 1463-1470 (2004).
  66. H. Hirata, T. Kuyama, M. Ono, and Y. Shimoyama, Nonequivalent spectra of unpaired electrons in field and frequency modulation, Journal of Magnetic Resonance, Vol. 168, No. 2, pp. 252-258 (2004).
  67. H. Hirata, T. Kuyama, M. Ono, and Y. Shimoyama, Detection of electron paramagnetic resonance absorption using frequency modulation, Journal of Magnetic Resonance, Vol. 164, No. 2, pp. 233-241 (2003).
  68. I. Salikhov, H. Hirata, T. Walczak, and H. M. Swartz, An improved external loop resonator for in vivo L-band EPR spectroscopy, Journal of Magnetic Resonance, Vol. 164, No.1, pp. 54-59 (2003).
  69. H. Hirata, Y. Yamaguchi, T. Takahashi, and Z.-W. Luo, Control characteristics of an automatic matching control system for in vivo EPR spectroscopy, Magnetic Resonance in Medicine, Vol. 50, No. 1, pp. 223-227 (2003).
  70. G. He, S. P. Evalappan, H. Hirata, Y. Deng, S. Petryakov, P. Kuppusamy, and J. L. Zweier, Mapping of the B1 field distribution of a surface coil resonator using EPR imaging, Magnetic Resonance in Medicine, Vol. 48, No. 6, pp. 1057-1062 (2002).
  71. H. Hirata, M. Ueda, M. Ono, and Y. Shimoyama, 1.1-GHz continuous-wave EPR spectroscopy with a frequency modulation method, Journal of Magnetic Resonacne, Vol. 155, No. 1, pp. 140-144 (2002).
  72. M. Ono, A. Suenaga, and H. Hirata, Experimental investigation of RF magnetic field homogeneity in a bridged loop-gap resonator, Magnetic Resonanc in Medicine, Vol. 47, No. 2, pp. 415-419 (2002).
  73. H. Hirata and Z.-W. Luo, Stability Analysis and Design of Automatic Frequency Control System for In Vivo EPR Spectroscopy, Magnetic Resonanc in Medicine, Vol. 46, No. 6, pp. 1209-1215 (2001); Erratum Vol. 49, No. 5, p. 977 (2003).
  74. H. Hirata, T. Walczak, and H. M. Swartz, Characteristics of an electronically tunable surface-coil-type resonator for L-band electron paramagnetic resonance spectroscopy, Review of Scientific Instruments, Vol. 72, No. 6, pp. 2839-2841 (2001).
  75. H. Hirata, T. Walczak, and H. M. Swartz, Electronically Tunable Surface-Coil-Type Resonator for L-band EPR Spectroscopy, Journal of Magnetic Resonance, Vol. 142, No. 1, pp. 159-167 (2000).
  76. H. Hirata and M. Ono, Impedance-matching system for a flexible surface-coil-type resonator, Review of Scientific Instruments,Vol. 68, No. 9, pp. 3528-3532 (1997).
  77. H. Hirata and M. Ono, A flexible surface-coil-type resonator using triaxial cable, Review of Scientific Instruments,Vol. 68, No. 9, pp. 3595-3596 (1997).
  78. H. Hirata, T. Walczak, and H. M. Swartz, An improved inductive coupler for suppressing a shift in the resonance frequency of electron paramagnetic resonance resonators, Review of Scientific Instruments, Vol. 68, No. 8, pp. 3187-3191 (1997).
  79. H. Hirata and M. Ono, Resonance frequency estimation of bridged loop-gap resonator for magnetic resonance measurements, Review of Scientific Instruments, Vol. 67, No. 1, pp. 73-78 (1996).
  80. H. Hirata, H. Iwai, and M. Ono, Analysis of a flexible surface-coil-type resonator for magnetic resonance measurements, Review of Scientific Instruments, Vol. 66, No. 9, pp. 4529-4534 (1995).
  81. Y. Sakamoto, H. Hirata, and M. Ono, Design of a Multicoupled Loop-Gap Resonator Used for Pulsed Electron Paramagnetic Resonance Measurements, IEEE Transactions on Microwave Theory and Techniques, Vol. 43, No. 8, pp. 1840-1847 (1995)
  82. H. Hirata and S. Ueha, Design of a Traveling Wave Type Ultrasonic Motor, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 42, No. 2, pp. 225-231 (1995).
  83. M. Ono, K. Ito, N. Kawamura, K. C. Hsieh, H. Hirata, N. Tsuchihashi, and H. KamadaA Surface-Coil-Type Resonator for in Vivo ESR Measurements, Journal of Magnetic Resonance, Series B, Vol. 104, pp. 180-182 (1994).
  84. H. Hirata and S. Ueha, Characterisitcs Estimation of a Traveling Wave Type Ultrasonic Motor, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 40, No. 4, pp. 402-406 (1993).
  85. H. Hirata and S. Ueha, Revolution Speed Characteristics of an Ultrasonic Motor Estimated from the Pressure Distribution of the Rotor, Japanese Journal of Applied Physics, Vol. 31, Suppl. 31-1, pp. 248-250 (1992).
  86. H. Hirata and S. Ueha, Force Factor Design of Disk Vibratrors Used for Ultrasonic Motors, Journal of the Acoustical Society of Japan (E), Vol. 13, No. 2, pp. 77-84 (1992).
  87. T. Takano, H. Hirata, and Y. TomikawaAnalysis of Nonaxisymmetric Vibration Mode Piezoelectric Annular Plate and its Application to an Ultrasonic Motor, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 37, No. 6, pp. 558-565 (1990).
  88. Y. Tomikawa, K. Adachi, H. Hirata, T. Suzuki, and T. Takano Excitation of Progressive Wave in a Flexural vibrating Transmission Medium, Japanese Journal of Applied Physics, Vol. 29, Suppl. 29-1, pp. 179-181 (1990).
  89. T. Takano, Y. Tomikawa, T. Ogasawara, H. Hirata, An Ultrasonic Motor Using Non-Axisymmetric Vibration Modes of a Piezo-Ceramic Annular Plate, Japanese Journal of Applied Physics, Vol. 28, Suppl. 28-2, pp. 202-205 (1990).
  90. T. Takano, H. Hirata, Y. Tomikawa, Non-Axisymmetric Contour Vibrations of Clamped Piezoelectric Annular Plate: Analysis for the Development of an Ultrasonic Motor, Journal of the Acoustical Society of Japan (E), Vol. 11, No. 3, pp. 161-172 (1990).
  91. Y. Tomikawa, T. Takano, H. Hirata, T. Ogasawara, An Ultrasonic Motor Using Non-Axisymmetric Vibration Modes of a Piezo-Ceramic Annular Plate, Japanese Journal of Applied Physics, Vol. 28, Suppl. 28-1, pp. 161-163 (1989).

Proceedings/Abstracts of International Conferences

  1. D. A. Komarov, Y. Ichikawa, K. Yamamoto, N. J. Stewart, S. Matsumoto, H. Yasui, I. A. Kirilyuk, V. V. Khramtsov, O. Inanami, H. Hirata. In vivo extracellular pH mapping of tumors using EPR. The Third Joint Conference of the Asia-Pacific EPR/ESR Society and The International EPR (ESR) Society (APES-IES 2018), 23rd–27th September 2018, IV19, Brisbane, Australia (2018). (Invited)
  2. D. A. Komarov, Y. Ichikawa, K. Yamamoto, N. J. Stewart, S. Matsumoto, H. Yasui, I. A. Kirilyuk, V. V. Khramtsov, O. Inanami, H. Hirata. In vivo extracellular pH mapping of tumors using electron paramagnetic resonance. 46th Annual Meeting of International Society on Oxygen Transport to Tissue (ISOTT 2018), 1st–5th July 2018, I-03, Keynote Talk, Seoul, Korea (2018). (Invited)
  3. H. Kubota, D. A. Komarov, S. Matsumoto, K. Yamamoto, H. Yasui, O. Inanami, I. A. Kirilyuk, V. V. Khramtsov, H. Hirata. Three-dimensional oxygen mapping using a pair of isotopic nitroxyl radicals and CW-EPR-based single-point imaging, EPR 2017: International Conference on Electron Paramagnetic Resonance Spectroscopy and Imaging of Biological Systems, 16th–21th July 2017, Oral Presentation 22, Morgantown, WV, USA (2017). (Invited)
  4. M. Miyake, Y. Nakai, I. Yamaguchi, H. Hirata, N. Kunugita, H. M. Swartz. In-vivo tooth dosimetry using a deployable L band EPR spectrometer, EPR 2017: International Conference on Electron Paramagnetic Resonance Spectroscopy and Imaging of Biological Systems, 16th–21th July 2017, Poster 36, Morgantown, WV, USA (2017).
  5. D. A. Komarov, H. Hirata. Fast backprojection-based reconstruction of spectral-spatial EPR images from projections with the constant sweep of a magnetic field, EPR 2017: International Conference on Electron Paramagnetic Resonance Spectroscopy and Imaging of Biological Systems, 16th–21th July 2017, Poster 44, Morgantown, WV, USA (2017).
  6. H. Kubota, H. Yasui, S. Matsumoto, O. Inanami, I. A. Kirilyuk, V. V. Khramtsov, H. Hirata. CW-EPR-based oxygen mapping technique using a pair of isotopic nitroxyl radicals, Xth International Workshop on EPR in Biology and Medicine, 2nd October–6th October 2016, Abstract Book p. 38, Krakow, Poland (2016). (Invited)
  7. H. Hirata, H. Kubota, H. Yasui, S. Matsumoto, O. Inanami, I. A. Kirilyuk, and V. V. Khramtsov. Development of a CW-EPR-based oxygen-mapping technique using a pair of isotopic nitroxyl radicals, Asia-Pacific EPR/ESR Symposium 2016, 28th August–2nd September 2016, IN-05, Irkutsk, Russia (2016). (Invited)
  8. H. Hirata, H. Kubota, H. Yasui, S. Matsumoto, O. Inanami, I. A. Kirilyuk, and V. V. Khramtsov. Feasibility study of a CW-EPR-based oxygen mapping technique using a pair of isotopic nitroxyl radicals, 58th Annual Rocky Mountain Conference on Magnetic Resonance (39th International EPR Symposium), Oral #178 (p. 55), Breckenridge, Colorado, USA (2016).
  9. H. Kubota, H. Yasui, S. Matsumoto, O. Inanami, I. A. Kirilyuk, V. V. Khramtsov, H. Hirata. Characteristics of 14N- and 15N-labeled dicarboxy-PROXYLs as oxygen-sensitive probes for CW-EPR-based single-point imaging (SPI), 58th Annual Rocky Mountain Conference on Magnetic Resonance (39th International EPR Symposium), Poster #223 (p. 70), Breckenridge, Colorado, USA (2016).
  10. A. Enomoto, H. Hirata. Sensitivity improvement under parallel detection in CW-EPR imaging, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 23th Annual Meeting and Exhibition, p. 2428, Toronto, Canada (2015).
  11. H. Sato-Akaba, H. Hirata. Development of low field MRI system running on the same magnetic circuit used for 750 MHz CW EPR imaging system, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 23th Annual Meeting and Exhibition, p. 3112, Toronto, Canada (2015).
  12. A. B. Flood, B. B. Williams, W. Schreiber, G. Du, V. A. Wood, M. M. Kmiec, S. V. Petryakov, E. Demidenko, H. M. Swartz, and the EPR Center Tooth Dosimetry Project Team. Advances in in vivo EPR tooth biodosimetry: Meeting the targets for initial triage following a large-social radiation event. Radiation Protection Dosimetry, Vol. 172, No. 1-3, pp. 72-80 (2016), doi: 10.1093/rpd/ncw165, published online 15 July 2016. (The EPR Center Tooth Dosimetry Project Team includes H. Hirata)
  13. W. Takahashi, Y. Miyake, H. Hirata. Artifact suppression in electron paramagnetic resonance imaging of 14N- and 15N-labeled nitroxyl radicals with asymmetric absorption spectra, Joint Conference of 9th Asia-Pacific EPR/ESR Symposium, 1st International EPR (ESR) Society Symposium, and 53rd SEST Annual Meeting (APES-IES-SEST 2014), P-47, Nara, Japan (2014).
  14. T. Ishii, H. Hirata. Simulation of RF magnetic fields in crossed loop resonators for 300 MHz pulsed EPR, Joint Conference of 9th Asia-Pacific EPR/ESR Symposium, 1st International EPR (ESR) Society Symposium, and 53rd SEST Annual Meeting (APES-IES-SEST 2014), P-40, Nara, Japan (2014).
  15. A. Enomoto, H. Hirata. Improvement of sensitivity on parallel CW-EPR image acquisition system, Joint Conference of 9th Asia-Pacific EPR/ESR Symposium, 1st International EPR (ESR) Society Symposium, and 53rd SEST Annual Meeting (APES-IES-SEST 2014), P-39, Nara, Japan (2014).
  16. A. Enomoto, H. Hirata. In vivo imaging of nitroxyl radicals in a mouse using surface coil array and parallel EPR detection, Joint Conference of 9th Asia-Pacific EPR/ESR Symposium, 1st International EPR (ESR) Society Symposium, and 53rd SEST Annual Meeting (APES-IES-SEST 2014), OP-8, Nara, Japan (2014).
  17. H. Hirata, V. V. Khramtsov. In vivo tumor extracellular pH monitoring using EPR spectroscopy, Magnetic Resonance: Fundamental research and pioneering applications (MR-70), Tue 06, Kazan, Russia (2014). (Invited)
  18. J. Goodwin, K. Yachi, M. Nagane, H. Yasui, Y. Miyake, O. Inanami, A. A. Bobko, V. V. Khramtsov, H. Hirata. Electron paramagnetic resonance spectroscopy for in vivo measurement of tumour extracellular pH: the effect of X-ray irradiation, Proceedings of Joint Annual Meeting ISMRM-ESMRMB 2014, p. 2932, Milan, Italy (2014).
  19. M. C. Emoto, H. Sato-Akaba, H. Hirata, H. G Fujii. Co-registered EPR and MRI of the mouse head indicates detailed distributions of piperidine nitroxides, Proceedings of Joint Annual Meeting ISMRM-ESMRMB 2014, p. 2926, Milan, Italy (2014).
  20. A. Enomoto, H. Hirata. Feasibility study of parallel detection of electron paramagnetic resonance imaging, Proceedings of Joint Annual Meeting ISMRM-ESMRMB 2014, p. 2917, Milan, Italy (2014). (ISMRM named Ayano Enomoto the Magna Cum Laude Merit Award.)
  21. J. Goodwin, K. Yachi, M. Nagane, H. Yasui, Y. Miyake, O. Inanami, A. A. Bobko, V. V. Khramtsov, H. Hirata. In vivo tumor extracellular pH monitoring using electron paramagnetic resonance, 41th Annual ISOTT Conference and EPR 2013 Conference, Forth presentation in Session 12, June 26, Dartmouth College, Hanover, NH, USA (2013).
  22. H. Sugawara, H. Hirata, S. Petryakov, B. B. Williams, A. B. Flood, H. M. Swartz. Development and Optimization of L-Band Surface-Coil Resonator for EPR Tooth Dosimetry, 41th Annual ISOTT Conference and EPR 2013 Conference, No. Fr12, Dartmouth College, Hanover, NH, USA (2013).
  23. Y. Miyake, X. Wang, M. Amasaka, K. Itto, S. Xu, H. Arimoto, H. Hirata. Strcture and reactivity of nAChR ligand enantiomers labeled by 14N- or 15N-nitroxyl radicals for simultaneous EPR imaging, 41th Annual ISOTT Conference and EPR 2013 Conference, No. Th10, Dartmouth College, Hanover, NH, USA (2013).
  24. Y. Miyake, X. Wang, M. Amasaka, K. Itto, S. Xu, H. Fujii, H. Arimoto, H. Hirata. Simultaneous imaging of an enantiomer pair by EPR using isotopic nitrogen labeling, 41th Annual ISOTT Conference and EPR 2013 Conference, No. Th06, Dartmouth College, Hanover, NH, USA (2013).
  25. A. Enomoto, H. Hirata, S. Matsumoto, K. Saito, S. Subramanian, M. C. Krishna, N. Devasahayamu. Development of four-channel surface coil array for 300 MHz pulsed EPR imaging, 41th Annual ISOTT Conference and EPR 2013 Conference, No. Th03, Dartmouth College, Hanover, NH, USA (2013).
  26. W. Takahashi, A. A. Bobko, I. Dhimitruka, H. Hirata, A. Samouilov, V. V. Khramtsov. DNP characterization of the phosphonated trityl probe: Potential for in vivo pH and pO2 mapping by PEDRI, 41th Annual ISOTT Conference and EPR 2013 Conference, No. Tu15, Dartmouth College, Hanover, NH, USA (2013).
  27. H. Hirata. MR imaging of oxidative stress: Electron paramagnetic resonance imaging –Challenges to functional imaging–, COST Action BM1203 EU-ROS Working Group Meeting, Budapest, Hungary (2013). (Invited)
  28. M. C. Emoto, H. Sato-Akaba, H. Hirata, and H. G. Fujii, Redox Map of Mouse Brain by Three-Dimensional EPR Imaging with Six-Membered Nitroxyl Radicals, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 21th Annual Meeting and Exhibition, p. 1986, Salt Lake City, USA (2013).
  29. M. C. Emoto, H. Sato-Akaba, H. Hirata, and H. G. Fujii, Differences in Distribution and Reduction Rate of BBB Permeable Nitroxides by in Vivo EPR Imaging Method, Free Radical Biology and Medicine, Vol. 53, pp. S65-S65, DOI: 10.1016/j.freeradbiomed.2012.10.195 (2012).
  30. M. C. Emoto, H. Sato-Akaba, H. Hirata, and H. G. Fujii, Distribution and time course of Blood-Brain Barrier-permeable nitroxides in mouse head by MRI and EPR imaging, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 20th Annual Meeting and Exhibition, p. 1709, Melbourne, Australia (2012).
  31. J. Goodwin, S. Koda, M. Ohfuchi, A. Pawlak, H. Yasui, V. Khramstov, and H. Hirata, Four-dimensional spectral spatial pH mapping of mouse tumour using Continuous Wave-Electron Paramagnetic Resonance imaging (CW-EPRI) and pH sensitive imidazoline nitroxide, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 20th Annual Meeting and Exhibition, p. 1708, Melbourne, Australia (2012).
  32. H. Fujii, K. Kawanishi, H. Sato-Akaba, M. Emoto, and H. Hirata, Detection of Blood-brain barrier disruption in a mouse model of transient cerebral ischemia by EPR imaging, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 19th Annual Meeting and Exhibition, Montreal, Canada, p. 1469 (2011).
  33. A. Pawlak, R. Ito, H. Fujii, and H. Hirata, Simultaneous CW-EPR imaging of isotopic nitroxyl radicals, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 19th Annual Meeting and Exhibition, Montreal, Canada, p. 1470 (2011).
  34. S. Koda, J. Goodwin, V. Khramtsov, H. Fujii, and H. Hirata, EPR-based pH mapping with a method of partially scanned spectral-spatial imaging, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 19th Annual Meeting and Exhibition, Montreal, Canada, p. 1471 (2011).
  35. A. M. Pawlak, R. Ito, H. Fujii, and H. Hirata, Simultaneous CW-EPR imaging of nitroxyl radicals and their 15N-labeled analogues: a method for studying metabolism of drugs in vivo, 7th Asia-Pacific EPR/ESR Symposium (APES 2010), Jeju, Korea, OL-25 (2010).
  36. M. Ohfuchi, H. Fujii, and H. Hirata, Automatic alignment method for 3D EPR/NMR co-registration imaging, 7th Asia-Pacific EPR/ESR Symposium (APES 2010), Jeju, Korea, PO-11 (2010).
  37. A. Enomoto and H. Hirata, Feasibility study of surface-coil array for CW-EPR imaging, A Joint Conference of the 14th In Vivo EPR Spectroscopy & Imaging and the 11th International EPR Spin Trapping/Spin Labeling (EPR2010), Sun Juan, Puerto Rico, P-12 (2010).
  38. H. Sato-Akaba, Y. Kuwahara, H. Fujii, and H. Hirata, Three-dimensional EPR imaging at an interval of 3.6 seconds, A Joint Conference of the 14th In Vivo EPR Spectroscopy & Imaging and the 11th International EPR Spin Trapping/Spin Labeling (EPR2010), Sun Juan, Puerto Rico, O-46 (2010) (Invited).
  39. H. Sato-Akaba, H. Fujii, H. Hirata, Development of Fast CW-EPR imaging, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 17th Scientific Meeting and Exhibition, Honolulu, HI, USA, p. 2477 (2009).
  40. H. Sato-Akaba, H. Hirata, Simultaneous 3D EPR image reconstruction and visualization during acquisition of projection data, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 17th Scientific Meeting and Exhibition, Honolulu, HI, USA, p. 2478 (2009).
  41. Y. Ikebata, H. Sato-Akaba, T. Aoyama, K. Itoh, H. Fujii, and H. Hirata, Superresolution EPR imaging: Phantom and animal experiments, A Joint Conference of the 13th In Vivo ESR/EPR Spectroscopy & Imaging and the 10th International EPR Spin Trapping/Spin Labeling (EPR2008), Fukuoka, Japan, O-7 (2008) (Invited).
  42. H. Hirata, P. Lesniewski, and H. M. Swartz, Improvement of a tunable surface-coil resonator for L-band EPR tooth dosimetry, Biodose-2008, Hanover, NH, USA, P-25 (2008).
  43. Y. Ikebata, H. Sato-Akaba, T. Aoyama, H. Fujii, K. Itoh, andH. Hirata, Superresolutiokn EPR Imaging: Phantom and Animal experiments, 6th Asia-Pacific EPR symposium, Cairns, Australia, p. 74 (2008) (Invited).
  44. Y. Ikebata, H. Sato-Akaba, H. Fujii, and H. Hirata, 3D superresolution EPR imaging of nitroxyl radicals in mice, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 16th Scientific Meeting and Exhibition, Toronto, Canada, p. 1726 (2008).
  45. H. Sato-Akaba, H. Fujii, and H. Hirata, EPR imaging of short-lifetime nitroxyl radicals in mouse head, Proceedings of International Society for Magnetic Resonance in Medicine (ISMRM) 16th Scientific Meeting and Exhibition, Toronto, Canada, p. 1727 (2008).
  46. N. Watanabe, H. Sato-Akaba, K. Nakagawa, and H. Hirata, Feasibility of spectral-spatial EPR imaging on diffusion of spin probes in biological tissues, A Joint Conference of the International Symposium on Electron Spin Science and the 46th Annual Meeting of the Society of Electron Spin Science and Technology, Shizuoka, Japan, P55 (2007).
  47. H. Sato-Akaba, H. Fujii, and H. Hirata, Fast 3D CW-EPR imaging with uniform distribution of projections, A Joint Conference of the International Symposium on Electron Spin Science and the 46th Annual Meeting of the Society of Electron Spin Science and Technology, Shizuoka, Japan, P53 (2007).
  48. H. Hirata, H. Sato-Akaba, and H. Fujii, New approaches to advanced CW-EPR imaging, A Joint Conference of the International Symposium on Electron Spin Science and the 46th Annual Meeting of the Society of Electron Spin Science and Technology, Shizuoka, Japan, 2A11 (2007).
  49. Y. Suzuki and H. Hirata, Development of tuning circuit for 650-MHz multi-coil parallel-gap resonator, A Joint Conference of the International Symposium on Electron Spin Science and the 46th Annual Meeting of the Society of Electron Spin Science and Technology, Shizuoka, Japan, 1A07 (2007).
  50. H. Abe, H. Sato-Akaba, and H. Hirata, Development of highly sensitive loop-gap resonator, A Joint Conference of the International Symposium on Electron Spin Science and the 46th Annual Meeting of the Society of Electron Spin Science and Technology, Shizuoka, Japan, 1A06 (2007).
  51. Y. Ikebata, H. Sato-Akaba, and H. Hirata, Three-dimensional superresolution EPR imaging, A Joint Conference of the International Symposium on Electron Spin Science and the 46th Annual Meeting of the Society of Electron Spin Science and Technology, Shizuoka, Japan, 1A05 (2007).
  52. H. Sato-Akaba, H. Abe, H. Fujii, and H. Hirata, Slice-selective images of free radicals in mice with modulated field gradient EPR imaging, A Joint Conference of the International Symposium on Electron Spin Science and the 46th Annual Meeting of the Society of Electron Spin Science and Technology, Shizuoka, Japan, 1A04 (2007).
  53. H. Sato-Akaba, H. Abe, H. Fujii, and H. Hirata, Slice-selective images of free radicals in mice with modulated field gradient EPR imaging, The 4th JSPS Core-to-Core Program Seminar: International In Vivo Redox Symposium, Shizuoka, Japan, P-1 (2007).
  54. H. Hirata, Tunable resonators and automatic control techniques in biomedical EPR spectroscopy, EPR2007 A Joint Conference of 12th In Vivo EPR Spectroscopy and Imaging and 9th International EPR Spin Trapping, Chicago, IL, USA, O-18 (2007) (Invited).
  55. H. Fujii, K. Sakata, Y. Katsumata, R. Sato, M. Kinouchi, M. Someya, S. Masunaga, M. Hareyama, and H. Hirata, Tissue oxygenation in a murine SCC VII tumor after X-ray irradiation as determined by EPR spectroscopy, EPR2007 A Joint Conference of 12th In Vivo EPR Spectroscopy and Imaging and 9th International EPR Spin Trapping, Chicago, IL, USA, P-34 (2007).
  56. H. Hirata, P. Lesniewski, and H. M. Swartz, Implementation of a 1.2-GHz tunable EPR resonator for tooth dosimetry, BiodosEPR-2006: 2nd International Conference on Biodosimetry and 7th International Symposium on EPR Dosimetry and Applications, Uniformed Services University of the Health Sciences, Bethesda, MD, USA, P-20 (2006).
  57. H. Hirata and H. Fujii, Automatic matching control circuit based on phase-sensitive detection scheme, EPR2005 A Joint Conference of 11th In Vivo EPR Spectroscopy and Imaging and 8th International EPR Spin Trapping, Columbus, OH, USA, p. 106 (2005).
  58. H. Fujii, M. Sakata, and H. Hirata, Development of EPR/MRI dual-mode imager and its application to oximetry, EPR2005 A Joint Conference of 11th In Vivo EPR Spectroscopy and Imaging and 8th International EPR Spin Trapping, Columbus, OH, USA, p. 105 (2005).
  59. H. Hirata, Engineering approaches for solving problems with animal movements during experiments, EPR2005 A Joint Conference of 11th In Vivo EPR Spectroscopy and Imaging and 8th International EPR Spin Trapping, Columbus, OH, USA, p. 100 (2005) (Invited).
  60. H. Hirata, T. Itoh, K. Hosokawa, Y Deng, H. Susaki, Systematic approach to cutoff frequency selection in continuous-wave electron paramagnetic resonance imaging, 47th Rocky Mountain Conference on Analytical Chemistry, Denver, CO, USA, Oral-98 (2005).
  61. H. Hirata, An engineering approach to solving the problem of animal movement in L-band EPR spectroscopy, 2nd Sendai-Berlin Joint Seminar on Advanced ESR, Tohoku University, Sendai, Japan (2004) (Invited).
  62. H. Hirata, H. Watanabe, M. Kumada, K. Itoh, and H. Fujii, Stability improvement of a CW-EPR spectrometer in animal experiments, Workshop on EPR Studies for the Study of Viable Systems (especially in vivo) and Related Techniques (especially oximetry), Dartmouth College, NH, USA (2004).
  63. H. Hirata, T. Kuyama, M. Ono, and Y. Shimoyama, A frequency modulation detection of electron paramagnetic resonance absorption, 10th International Workshop on Bio-medical ESR Spectroscopy and Imaging, Fukuoka, Japan, O-10 (2003).
  64. H. Hirata, Y. Yamaguchi, T. Takahashi, and Z.-W. Luo, Control characteristics of an automatic matching control system for in vivo EPR spectroscopy, 10th International Workshop on Bio-medical ESR Spectroscopy and Imaging, Fukuoka, Japan, O-7 (2003).
  65. H. Hirata, Instrument development of continuous-wave electron paramagnetic resonance spectroscopy for biological applications, International Symposium on Microwave Science and Its Application to Related Fields, Nara, Japan, 2C-3 (2002) (Invited).
  66. G. He, S. P. Evalappan, H. Hirata, S. Petryakov, P. Kuppusamy, and J. L. Zweier, B1 mapping of a surface coil resonator using EPR imaging, International Society for Magnetic Resonance in Medicine Tenth Scientific Meeting & Exhibition, Honolulu, Hawaii, USA (2002).
  67. M. Miyake, A. Iwasaki, Y. Ohbayashi, S. Nagahata, H. Hirata, and H. M. Swartz, Potential for human in vivo EPR dosimetry using a low-frequency spectrometer -effect of dental diagnostic X-ray and demonstration of the radiation induced EPR signal from the teeth of patients who underwent radiation therapy fpr oral cancer, 9th International workshop on EPR studies of Viable Systems (especially in vivo) and related techniques, Dartmouth College, NH, USA, W-13 (2001).
  68. I. Salikhov, Y. Noda, T. Walczak, O. Y. Grinberg, H. Hirata, and H. M. Swartz, Oxygen dependence of the spin-lattice relaxation rate on lithium phthalocyanine, 9th International workshop on EPR studies of Viable Systems (especially in vivo) and related techniques, Dartmouth College, NH, USA, M-11 (2001).
  69. H. Hirata, T. Walczak, Z.-W. Luo, H. M. Swartz, and M. Ono, Tunable EPR resonators: control techniques and advantages for biomedical EPR study, 9th International workshop on EPR studies of Viable Systems (especially in vivo) and related techniques, Dartmouth College, NH, USA, TH-2 (2001).
  70. H. Hirata, A tunable EPR resonator and control techniques for in vivo EPR experiments, Joint Symposium on Bio-Sensing and Bio-Imaging, Yamagata, Japan, 1A-4 (2001).
  71. A. Suenaga, M. Ono, H. Hirata, an H. Susaki, On optimum bridge angle of a 300 MHz bridged loop-gap resibator, International Symposium on In Vivo ESR Spectroscopy, Kyushu University, Japan, P-18 (2000).
  72. H. Hirata, T. Walczak, and H. M. Swartz, A method for calculating the radio frequency magnetic field in a tunable surface-coil-type resonator for L-band EPR spectroscopy, International Symposium on In Vivo ESR Spectroscopy, Kyushu University, Japan, P-5 (2000).
  73. M. Ono and H. Hirata, A design of 300 MHz bridged loop-gap resonators used for in vivo EPR imaging, International Symposium on In Vivo ESR Spectroscopy, Kyushu University, Japan, O-2 (2000).
  74. H. Hirata, T. Walczak, and H. M. Swartz, Electronically tunable surface-coil-type resonator for L-band EPR spectroscopy, International Workshop on Techniques and Bio-Medical Applications of In Vivo EPR and PEDRI, University of Aberdeen, Scotland, UK, p. 3 (1999).
  75. M. Ono, T. Akutagawa, H. Hirata, and Y. Shimoyama, Development of 350 MHz Pulsed EPR ｾ Relation between resonator Q-value and output responce, International Workshop on Techniques and Bio-Medical Applications of In Vivo EPR and PEDRI, University of Aberdeen, Scotland, UK, p. 42 (1999).
  76. M. Ono, H. Hirata, M. Hiramatsu, and Y. Shimoyama, Optimum Design of a Surface Coil EPR Resonator used for Rat Striatum, International Workshop on Techniques and Bio-Medical Applications of In Vivo EPR and PEDRI, University of Aberdeen, Scotland, UK, p. 43 (1999).
  77. H. Hirata, T. Walczak, M. Ono, and H. M. Swartz, An electronically tunable surface-coil-type resonator for L-band EPR spectroscopy, EPR Workshop on In Vivo EPR and Related Studies, Dartmouth College, Hanover, NH, USA, p. 34 (1998).
  78. M. Ono, Y. Asahi, H. Hirata, and Y. Shimoyama, A new frequency modulation scheme of electron paramagnetic resonance spectroscopy , EPR Workshop on In Vivo EPR and Related Studies, Dartmouth College, Hanover, NH, USA, p. 65 (1998).
  79. M. Ono, T. Yamura, H. Hirata, and M. Hiramatsu, Development of a high performance surface-coil-type resonator for the striatum of rat for the brain function, 2nd International Confernce on Bioradicals and 5th International WOrkshop on ESR (EPR) Imaging and in vivo ESR Spectroscopy, Yamagata, p. 59 (B348P) (1997).
  80. H. Hirata and M. Ono, Estimation of the input impedance for a flexible surface-coil-type resonator, Proc. of 2nd International Confernce on Bioradicals, Yamagata, pp. 238-240 (1997).
  81. H. Hirata, H. Iwai, and M. Ono, Sensitivity estimation of a flexible surface-coil-type resonator, Proc. of II International Workshop on "in vivo" ESR and ESR Imaging, p. 18 (1995).
  82. M. Ono, H. Iwai, and H. Hirata, A Surface-Coil-Type Resonator Using Coaxial Lines for in Vivo ESR Measurements, Magnetic Resonance in Medicine (Japan), Vol. 6, pp. 31-33 (1994).
  83. H. Hirata, H. Iwai, M. Ono, Analysus of a Flexible Surface-Coil-Type Resonator for ESR Measurements, Magnetic Resonance in Biomedical Research (H. Watari ed., National Institute for Physiological Sciences, Okazaki), EPR-P5 (1994).
  84. H. Hirata, M. Ono, K. Ito, N. Kawamura, N. Tsuchihashi, and H. Kamada, A surface coil type resonantor for in vivo ESR measurement, Workshop on in vivo EPR and EPR studies of viable biological systems, held in Dartmouth Medical School, NH, U.S.A. (1993).
  85. H. Hirata and S. Ueha, Estimation of Revolution Speed Characteristics of Ultrasonic Motor Using the Stress Distribution of the Rotor, Proc. of 14th International Congress on Acoustics, Vol. 3, C5-1 (1992).
  86. T. Takano, Y. Tomikawa, T. Ogasawara, and H. Hirata, Constructions and Characteristics of Ultrasonic Motor Using a Piezo-Ceramic Annular Plate, Proc. of IEEE 1989 Ultrasonic Symposium, Vol. 2, pp. 735-738 (1989).