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高周波電磁場・強磁場に対するDNAの電気伝導特性の研究

Research Project

Project/Area Number 15654045
Research Category

Grant-in-Aid for Exploratory Research

Allocation TypeSingle-year Grants
Research Field Condensed matter physics II
Research InstitutionThe University of Tokyo

Principal Investigator

前田 京剛  東京大学, 大学院・総合文化研究科, 助教授 (70183605)

Co-Investigator(Kenkyū-buntansha) 北野 晴久  東京大学, 大学院・総合文化研究科, 助手 (00313164)
Project Period (FY) 2003 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
KeywordsDNA / マイクロ波 / 電気伝導 / 粉末 / 磁場効果 / 電気伝導度 / ホッピング伝導 / 交流電気伝導 / 水分子 / 空洞共振器 / サケの精子 / 電磁波と生体 / 非接触 / 誘電率 / 粉末試料
Research Abstract

(1)昨年度予備的に得られていた結果の再現性の確認を行い,確実性が得られたので現在論文を準備中である。すなわち,サケの精子のDNAの粉末を乾燥ヘリウムガス中に封入し,10GHzでの複素応答を室温から液体窒素温度(77K)までで測定した。測定した試料の複素応答データに絶縁体に対する解析方法を適用し,10GHzにおける電気伝導度と誘電率をもとめた。その結果,電気伝導度は,室温で,3x10^<-3>(ohmcm)^<-1>程度であり,温度とともに伝導度が減少する半導体的な振る舞いをすることがわかった。温度依存性から見積もった活性化エネルギーは50meV-70meVである。文献にある水分子の高周波伝導度との比較から,この値は,水分子のそれよりも一桁以上大きく,DNAに固有のものであると考えられる。同じく,文献に報告されている「100GHzでは水分子の電気伝導度しか測定されなかった」という事実も定量的に考え合わせると,DNAの電気伝導度の周波数依存性としては,ホッピングタイプの伝導が得られた。この候補としては,ヌクレオチドの一次元スタックの方向のホッピング伝導が考えられる。
(2)磁場を印加して同様の測定を行ったが明瞭な変化は観測されなかった。このことから,生体にたいしてなんらかの磁場効果があるか否かに関しては(予備的ではあるが)否定的な結論が得られた。
(3)粉末に対する複素伝導度測定の応用として,プロトン互変異性をしめす2-ヒドロキシフェナジンの10GHzにおける複素伝導度測定を行った結果,伝導度および誘電率に新たな相転移を見出した。現在この現象の解明を急いでいる。
(4)THzの複素伝導度測定装置の製作を開始したが,本研究終了までに完成には至らなかった。

Report

(3 results)
  • 2005 Annual Research Report
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • Research Products

    (35 results)

All 2006 2005 2004 Other

All Journal Article (16 results) Publications (19 results)

  • [Journal Article] Critical microwave-conductivity fluctuations across the phase diagram of superconducting La_<2-x>Sr_xCuO_4 thin films2006

    • Author(s)
      H.Kitano
    • Journal Title

      Phys.Rev.B 73

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Direct observation of rectified motion of vortices by Lorentz microscopy2006

    • Author(s)
      Y.Togawa
    • Journal Title

      Pramana-Journal of Physics 66

      Pages: 279-287

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Microwave conductivities of high-Tc oxide superconductors2005

    • Author(s)
      A.Maeda
    • Journal Title

      J.Phys.Condens.Matter 17

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Effect of thermal expansion in microwave conductivity measurement2005

    • Author(s)
      T.Ohashi
    • Journal Title

      Physica C 426-431

      Pages: 240-245

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Nanoscale friction : kinetic friction on magnetic flux quanta and charge-density waves2005

    • Author(s)
      A.Maeda
    • Journal Title

      Phys.Rev.Lett. 94

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Direct observation of rectified motion of vortices in a niobium superconductor2005

    • Author(s)
      Y.Togawa
    • Journal Title

      Phys.Rev.Lett. 94

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Investigation of a new technique to measure large dielectric constant at microwave frequencies using the enclosed cavity perturbation method2005

    • Author(s)
      R.Inoue
    • Journal Title

      Proc.of the 1^<st> Meeting on Applied Physics, Badajoz, Spain (in press)

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Microwave conductivities of high-Tc oxide superconductors and related2005

    • Author(s)
      A.Maeda
    • Journal Title

      J.Phys.Condens.Matter 17

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Nanoscale friction : Kinetic friction of magnetic flux quanta and charge-density waves2005

    • Author(s)
      A.Maeda
    • Journal Title

      Phys.Rev.Lett. 94

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Geometrical factors in the measurement of high temperature superconductors by the enclosed cavity perturbation technique2004

    • Author(s)
      R.Inoue
    • Journal Title

      Proc.of 2003 Asia-Pacific Microwave Conference (APMC'03),Seoul, FE6-5,extended abstract 3

      Pages: 2040-2043

    • Related Report
      2004 Annual Research Report
  • [Journal Article] A nondestructive method of measureing dielectric properties of substrate at microwave and millimeter-wave frequencies using an open-ended coaxial resonator probe2004

    • Author(s)
      R.Inoue
    • Journal Title

      Proc.of the 1^<st> Meeting on Applied Physics, Badajoz, Spain (in press)

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Highly accurate real-time method of determining resonant characteristics by the complex transmission coefficient data2004

    • Author(s)
      R.Inoue
    • Journal Title

      IEEE Trans.Microwave Theory and Tech. 582

      Pages: 2163-2168

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Microwave conductivity of fullerene intercalation compounds : Mott transition driven by the orthorhombic distortion2004

    • Author(s)
      H.Kitano
    • Journal Title

      Proc.Fullerens, Nanotubes, and carbon Nanoclusters Symposia, France.2003,The Electrochemical Society, Inc.)

      Pages: 469-473

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Frequency dependent microwave conductivity of La_<2-x>Sr_xCuO_4 thin films2004

    • Author(s)
      H.Kitano
    • Journal Title

      Physica C 412-414

      Pages: 130-133

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Impurity effect on the electronic state of the vortex core in the mixed state of Yba_2Cu_3O_y2004

    • Author(s)
      K.Kinoshita
    • Journal Title

      Physica C 412-414

      Pages: 530-534

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Study of kinetic friction of solid using driven lattice of quantized vortex in high-temperature superconductors -a new route to study microscopic tribology-2004

    • Author(s)
      A.Maeda
    • Journal Title

      Proc.1^<st> Meeting on Applied Physics, Badajox, Spain (in press)

    • Related Report
      2004 Annual Research Report
  • [Publications] R.Inoue: "Double sphere model in the enclosed cavity perturbation"J.Appl.Phys.. 93. 2736-2745 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] A.Maeda: "Sliding conduction by the quasi one-dimentional charge-ordered state in SR_<14-x>Ca_xCu_<24>O_<41+δ>"Physical Review B. 67. 115115-115119 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] K.Kinoshita: "Millimeter wave and microwave electrodynamic spectroscopy of YBa_2(Cu_<1-x>Zn_x)_3O_y in the Meissner and mixed state"Physica C. 388-389. 417-418 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] H.Kitano: "Nonlinear conductivity in the slightly hole-doped Sr_<14-x>Ca_xCu_<24>O_<41> ladder compounds"Physica C. 388-389. 231-232 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] K.Iwaya: "Electronic state of NbSe_2 investigated by STM/STS"Physica B. 329-333. 1598-1599 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] A.Maeda: "Dynamic phase diagram of vortices in high-Tc superconductors determined by experimental studies"Physica B. 329-333. 1346-1347 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] R.Inoue: "The inverse analysis of the enclosed cavity perturbation technique"Physica B. 329-333. 1546-1547 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Y.Togawa: "Dynamic phase diagram of driven vortices in Bi_2Sr_2CaCu_2O_y"J.Low Temp.Phys.. 131. 907-911 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] H.Kitano: "Microwave conductivity of superconducting and insulating fullerides"J.Low Temp.Phys. 131. 1251-1258 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] A.Maeda: "Effect of impurities on the electronic structure of vortex core investigated by microwave surface impedance measurement"J.Low Temp.Phys. 131. 969-973 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Y.Iwasa: "Effect of impurities on the electronic structure of vortex core investigated by microwave surface impedance measurement"Physica B. 388-389. 615-616 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] T.Hanaguri: "An instrument for low-and variable-temperature-wave surface impedance"Rev.Sci.Instrum. 74. 4436-4441 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] A.Maeda: "Study of kinetic friction of solid using driven lattice of quantized vortex in high-temperature superconductors -a new route to study microscopic tribology"Proc.1^<st> Meeting on Applied Physics, Badajoz, Spain. (in press).

    • Related Report
      2003 Annual Research Report
  • [Publications] K.Kinoshita: "Impurity effect on the electronic state of the vortex core in the mixed state of Yba_2Cu_3O_y"Physica C. (in press).

    • Related Report
      2003 Annual Research Report
  • [Publications] H.Kitano: "Frequency dependent microwave conductivity of La_<2-x>Sr_xCuO_4 thin films"Physica C. (in press).

    • Related Report
      2003 Annual Research Report
  • [Publications] H.Kitano: "Microwave conductivity of fullerene intercalation compounds : Mott transition driven by the orthorhombic distortion"Proc.Fullerenes, Nanotubes, and Carbon Nanoclusters Symposia, France.2003. 469-473 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] R.Inoue: "A nondestructive method of measureing dielectric properties of substrate at microwave and millimeter-wave frequencies using an open-ended coaxial resonator probe"Proc.1^<st> Meeting on Applied Physics, Badajoz, Spain. (in press).

    • Related Report
      2003 Annual Research Report
  • [Publications] R.Inoue: "Investigation of a new technique to measure large dielectric constant at microwave frequencies using the enclosed cavity perturbation method"Proc.1^<st> Meeting on Applied Physics, Badajoz, Spain. (in press).

    • Related Report
      2003 Annual Research Report
  • [Publications] R.Inoue: "Geometrical factors in the measurement of high temperature superconductors by the enclosed cavity perturbation technique"Proc.of 2003 Asia-Pacific Microwave Conference(APMC'03),Seoul, extended abstract. 3. 2040-2043 (2003)

    • Related Report
      2003 Annual Research Report

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Published: 2003-04-01   Modified: 2020-05-15  

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