| LEDs(light emitting diodes) have become new attractive solid light sources with superiority in high reliability, high brightness, long life and high energy efficiency and extensively been used in the area of big screen displaying, traffic signal lights, multimedia information storage and lighting. Whether in production value or in output, LEDs was dominating over the semiconductor photoelectricity apparatus. In recent years the potential for the development of LEDs for study of the visible light function in life science is also well recognized despite the difficulties to be overcome. In this paper three LED biology light sources were developed and have been used for cell biology experiments.In the first part of this thesis, the reasons of develop LED biology light source have been discussed from the effects of non-concern homochromy light on cells, the mechanisms and non-resonance characters of photobiomodulation on cells, the biological information model of photobiomodulation(BIMP) of low intensity laser(LIL) proposed by Professor Liu TCY. Recent advance of investigations of LEDs irradiation in life science were summarized in the second part of this thesis. Applications of LEDs to plant, animal cell, animal model, human clinical, biomaterial, environment survey and scientific research were review in the literatures. It is highly important for photobiomodulation on cells to measure irradiation dose, light intensity and uniformity. Presently, LED biology application equipments are rarely function above Because of its business purpose. So it is necessary to develop a set of LED biology light sources with different intensity. This work will make LED light biology technique more standardization and practicality.Three LEDs biology light sources with different intensity for cell or tissue culture have been developed in the third part of this thesis. A concave (convex) lens to expand the beams of light, to focus the rays of light and an array of LEDs being set in the sphere connected with Fresnel lenses are three newly-designed in our systems. Ineach source the illumination can easily be adjusted by selection of four parameters respectively. The illuminations radiate from three systems were measured and their experiential formulae for calculating illumination were obtained by SPSS. The illumination of light from the three LED systems ranges from: 0.0021 to 0.9961 W/cm2 with the spot diameter 20 mm in low intensity LEDs source, the Standard Deviation is 0.02 W/cm2(n=40, Mean: 0.71 W/cm2); 0.3579 to 11.2286 W/cm2 with the spot diameter 30 mm in moderate intensity LEDs source, the Standard Deviation is 0.02 W/cm2(n=60, Mean: 6.37 W/cm2); 0.3579 to 11.2286 W/cm2 with the spot diameter 40 mm in high intensity LEDs source, the Standard Deviation is 0.02 W/cm2(n=80, Mean: 71.54 W/cm2). All the formulae get by SPSS was significantly different from P-test (P<0.05). The measured illuminations show not only they agree with calculations but also their distributions are all uniformity. The formulae get by SPSS is reliable. These LEDs light sources are not only adjustment and uniformity but also smaller, less expensive, required less power, generated less heat. Especially, the pattern of the construct both aggregate and desegregate in design was to realize different light intensity illumination on same biology sample at the same time. The selectivity, work efficiency and experiment veracity have been improve greatly.In the fourth and fifth part of this thesis, the investigations of red LEDs light with the wavelength of 640 ?17nm on cell accelerating proliferation and controlling apoptosis using our moderate intensity LEDs source were carried through.In promote cell proliferation, the effects of LEDs with the two irradiances of 5.93 W/m2 and 7.13 W/m2 on the proliferation of human skin fibroblasts have been explored. After 48 hours, cells were counted. After 89mJ/cm2 and 214mJ/cm2 irradiation, the proliferation of the cells showed no difference compared with the control group. The cells proliferation was enhanced b...
|
PDF Full Text Request