ABSTRACT
The effects of ultrasonic irradiation at different frequencies, i.e. 0.25, 0.5, 1, and 5 MHz, on the biological reaction of the single cell creature have been investigated. When multi-cell creature is exposed to ultrasound, this reaction will lead the biological effect becomes complex. Therefore, in this dissertation, a single cell creature is chosen to study the biological effects induced by ultrasound exposure. The paramecium, which possesses many features typical of higher-order animal cells, was considered as an appropriate choice for this study. The ability shown by ultrasound in promoting and/or accelerating many reactions has been shown to be a useful field. The resonant frequency of paramecium by using the ultrasound irradiation is an important parameter in this research. All other parameters being kept constant, it has been ascertained that an appropriate frequency value of ultrasound can be selected, capable of driving a biological reaction to its suitable yield. The oscillation of the cells in response to the ultrasound radiation is simulated using Rayleigh-Plesset¡¦s bubble activation theory. The resonant frequency of the unicellular creature is then calculated. In the experiment, the resonant (0.5 and 1 MHz) and non-resonant (0.25 and 5 MHz) frequencies were employed.
The theoretical resonant frequency of the paramecium vacuole is among 0.5013~1.2703 MHz. In this thesis, the experiment included two different series. The exposure intensity is the major subject of the first experimental series to study the bioeffect of ultrasound. The waveform was set to the tone pulse mode, pulsing 1:1. The exposure duration was continued and maintained 5 minutes. For a given frequency, exposures of the paramecium were made over a range of intensities spanning 0 to 1.7 mW/cm2. The second experimental series was focused on the exposure duration of the ultrasound. The transducers were operating in a pulsed mode with two duty cycles of 1:1 and 1:9. All insonated samples were exposed to ultrasound with a spatial peak temporal peak intensity (SPTP) of 0.127 mW/cm2. The total ¡§with signal¡¨ time was about 6 minutes in each trial. In addition, the control samples and the treated samples would be re-incubated up to the 96 hr. When the 1 MHz frequency of ultrasound was irradiated in the samples, there was about 24% inhibition rate and 30% enhancement rate in the first experimental series. The 0.5 MHz frequency of ultrasound, which approaches to the resonant frequency range, also appeared the inhibitive and beneficial effect. In the second experimental series, the relative growth number was about 32.4% higher than that of unexposed sample. The inhibition or enhancement growth conditions did not appear apparently during irradiation the non-resonant frequency of ultrasound. Moreover, experimental evidence suggests that the sustaining growth effect can be expected, when the irradiation time is divided into parts.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-1229103-114840 |
| Date | 29 December 2003 |
| Creators | Huang, Yi-Cheng |
| Contributors | Ho-Yih Liu, Jao-Hwa Kuang, Shiuh-Kuang Yang, Ruey-Chang Wei, Mao-Xiong Huang, Shih-Jeh Wu, Yung-Chun Lee |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1229103-114840 |
| Rights | restricted, Copyright information available at source archive |
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