The 4th Workshop on Biological Applications of Plasma/Photon Processing
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Novel Endoscopic Diagnosis and Therapy
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| 中赤外波長可変レーザーを用いた新規内視鏡下診断・治療 | ||
| Hisanao Hazama1, Katsunori Ishii1, Kunio Awazu1,2 | ||
| 1Graduate School of Engineering, Osaka University 2Research Institute of Nuclear Engineering, University of Fukui |
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| 間久直1、石井克典1、粟津邦男1,2 | ||
| 1大阪大学大学院工学研究科、2福井大学附属国際原子力工学研究所 | ||
| Since there are many characteristic absorption lines caused by molecular vibrations in the mid-infrared (MIR) wavelength range, the range is often termed the molecular fingerprint region. A novel system for endoscopic diagnosis and selective treatments of gallstones, atherosclerosis, etc. using a MIR tunable pulsed laser, the hollow optical fibers, and the attenuated total reflection (ATR) spectroscopy has been developed. The MIR laser tunable within a wavelength range of 5.5–10 µm was obtained with difference-frequency generation (DFG) between a Nd:YAG and a tunable Cr:forsterite lasers. An absorption spectrum of cholesterol was measured with an ATR probe by scanning the wavelength of the MIR-DFG laser, and the spectrum was in good agreement with that measured with a commercial Fourier transform infrared spectrometer (FT-IR). Human gallstones were efficiently ablated by irradiating the MIR-DFG laser at the wavelength strongly absorbed by the human gallstones. Selective removal of atherosclerotic lesions has also been successfully demonstrated by irradiating the MIR-DFG laser at a wavelength of 5.75 µm where the ester bond in the cholesterol ester has characteristic absorption. | ||
Biological imaging by using Raman scattering
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ラマン散乱を用いたバイオイメージング | |
| Katsumasa Fujita | ||
| Osaka University | ||
| 藤田克昌 | ||
| 大阪大学 | ||
| Raman spectroscopy has been utilized for investigating molecular structure,
condition, and environment. Since Raman spectroscopy can monitor molecular
vibration frequency, it enables us to detect molecules in a living cell
without any labeling. However, it had been difficult to use Raman scattering
to image living biological samples because of the small Raman scattering
cross-section. We have developed a Raman microscope with a slit-scanning
technique, which allows us to measure Raman spectra from multiple points
in a sample simultaneously and obtain a Raman scattering image in a several
minutes. By using the Raman microscope, we successfully observed a distribution
of proteins and lipid molecules in a living cell. We also observed dynamics
of proteins and lipids in cell division. The developed technique can also
be applied to detecting exogenous chemicals, such as drugs, and to investigate
conditions of biological tissues. We also utilized surface-enhanced Raman
scattering (SERS) for further improvement of detection efficiency of Raman
scattering by introducing gold nanoparticles into a living cell. |
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Development of odor detector for conservation of cultural properties |
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| 文化財保存のためのニオイ分析装置の開発 | ||
| Masato Kiuchi | ||
| AIST | ||
| 木内正人 | ||
| 産総研 | ||
| Cultural properties like wall-paintings in ancient tombs and caves are damaged by microorganisms. For conservation of cultural properties, detection of the initial stage of growth of microorganisms is important. We are developing an odor detector to find out the microbial volatile organic compounds (MVOCs). For molecular separation, ion mobility spectrometry technique is applied. The apparatus is portable, battery-driven and remote-controllable by cell phone network. | ||
Inactivation Mechanism of Bacteriophages Exposed to Atmospheric Pressure Cold Plasma |
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| 大気圧低温プラズマによるバクテリオファージの不活化とそのメカニズム | ||
| Hachiro Yasuda | ||
| Toyohashi University of Technology | ||
| 安田八郎 | ||
| 豊橋技術科学大学 | ||
| Inactivation mechanisms of plasma treated microorganisms are still major subjects. We have invented a biological assay which evaluates in vivo DNA damage of the viruses treated with non-thermal atmospheric pressure plasma in air. Different doses of the plasma were applied to wet state of λ phage particles under neutral pH and near the room temperature. From each sample of discharged λ phages, DNA was purified and subjected to in vitro DNA packaging reactions. The re-packaged phages consist of the DNA from discharged phages and brand-new coat proteins. Survival curves of the re-packaged phages showed extremely large D value (D=25 s) compared to the previous D value (D=3 s) obtained from the survival curves of the discharged phages. The results indicate the evidence that DNA damage hardly contributed to the inactivation. Damage in coat proteins proved to be responsible for inactivation of λ phages treated with non-thermal atmospheric pressure plasma. | ||
The effect of plasma treatment on bone |
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| Shinji Imade, Ryuji Mori, Wang Ying Xu, Yuji Uchio | ||
| Shimane Univ. School of Medicine | ||
| Purpose: To evaluate the effect of bone surface treatment using gas plasma on healing and bone fusion. Methods: Bone pegs were made from bovine cortical bone using a numerically controlled lathe precision machine (arithmetic mean roughness (Ra) < 0.6 μm), and plasma treatment was performed upon implantation of the pegs in a total of 34 knees of 17 Japanese white rabbits (gas: He 3L+O2 2L, electric power: 150 W, treatment time: 1 hour). At the time of surgery and 10 days later, mechanical tests and micro-computed tomography were performed. Results: At the time of surgery, the push-out forces were less than 0.3N. Ten days after surgery, a significant difference was detected in the push-out forces between plasma-treated bone pegs and non-treated pegs (363.9 ± 115.8 vs. 288.2 ± 100.1 N (mean ± SD), respectively). In micro-computed tomography, minute new bones bridged between bone pegs and the recipient bones, and plasma-treated bone pegs had more bridging than did non-treated pegs (P=0.01). Conclusion: Plasma surface treatment on bone had a positive effect on bone-to-bone fusion 10 days postoperatively. |
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Micro-Spot Atmospheric Pressure Plasma Production for the Plasma Medicine |
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| プラズマ医療用マイクロスポット大気圧プラズマの生成 | ||
| Takamichi HIRATA | ||
| Tokyo City Universit | ||
| 平田孝道 | ||
| 東京都市大工 | ||
| For the diversified plasma applications to biomedical engineering, we carried
out the experiments about the direct ion/radical irradiation to the body
tissues and cells using micro-spot atmospheric pressures plasma source.
When cells were irradiated with the plasma, generated from glass capillary
tip, the stromatolysis due to surface interaction such as collision or
ionization of gas molecules was hardly observed in the preliminary experiment.
Furthermore, it seems that skin damage of small animals (mainly rats) was
not observed. |
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Biological application of the free radicals in the liquid processed by plasmas |
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| 「プラズマ誘起フリーラジカルのバイオ応用」 | ||
| Katsuhisa Kitano | ||
| Osaka Univ. | ||
| 北野勝久 | ||
| 大阪大学大学院工学研究科 原子分子イオン制御理工学センター | ||
| Recent successful research on atmospheric plasma jets has enabled non-conventional plasma processing. Due to its low gas temperature, as shown, this type of jets is desirable for plasma processing in liquid. While plasmas generated by arc or streamer discharges often cause local energy concentration and high gas temperatures, non-thermal plasma jets with low gas temperatures have the advantage of being able to treat soft materials such as solutes in liquids, organic materials, and living organisms. Though ions of plasma may play important roles in conventional plasma processings in vacuum, fast electrons of plasmas that generate free radicals are thought to be essential in plasma processing in liquids. Various chemical reactions, such as reduction, polymerization and sterilization, are promoted in liquid by non-thermal plasma applications. The fundamental question regarding such new chemical reaction environments is what kinds of species in plasmas cause these reactions. We have studied free radical formation in water after plasma exposure, using electron spin resonance (ESR) with/without a spin-trapping method. Some atomic species in the gas phase have been found to be converted to free radicals in liquid by plasma application. |