In this paper, the stability of Al<sub>2</sub>O<sub>3</sub> nano-particles in water were investigated at different pH values and different concentration of sodium dodecylbenzenesulfonate (SDBS) dispersant by measurement of the zeta potential and
absorbency. The experimental results show that zeta potential is relation with absorbency, and the higher magnitude of
zeta potential corresponds to the higher absorbency, and the better dispersion and good stability of the Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O nano-suspensions. It is also found that the concentration of SDBS can significantly affect the value of zeta potential and absorbency. The experimental results show that for SDBS there is an optimizing concentration in the nanofluids which
can induce high zeta potential and high absorbency, and that in 0.1% Al<sub>2</sub>O<sub>3</sub> -H<sub>2</sub>O nano-suspensions the optimizing concentration of SDBS is 0.09%, which has the best disperse results of the nanofluids.
Ulcerative colitis (UC) is an inflammatory destructive disease of the large intestine occurred usually in the rectum and lower part of the colon as well as the entire colon. In this paper, the influence of IL-1α and IL-4 on the experimental ulcerative colitis by light emitting diode ( LED ) (λ: 632.8nm; power: 4.0mw) applied to colon directly were studied. Making 30 rats into 3 groups: LED curative group, model group, normal control group. There were 10 rats of each group. We used glacial acetic acid (5%) and trinitro-benzene-sulfonic acid (TNBS) (1%) intra-anally to replicate the rat model of ulcerative colitis. After a week treatment with administrating LED rectal irradiation to curative group, 30mm each time, once per day, the histopathological studies in colonic tissue were performed, and the expression and distribution of IL-lα and IL-4 in colonic tissues were investigated by immunohistochemical staining. The extent of the Colonic tissue injury in LED curative group was not as significant as that in the model group. Compared with model group, the content of MDA in LED curative group was reductived and the activity of SOD was increased significantly, and the expression and distribution of IL-lα in LED curative group was depressed significantly, however the expression and distribution of IL-4 in LED curative group was increased obviously. This results show that the LED rectal irradiation can protect colonic mucosa from the experimental ulcerative colitis in rats, and suggest that the effects may be related to the photobiomodulation and immunomodulation of LED.
Based on Pennes equation, the influences of the intensity and the impulse frequency of laser acupuncture on the point tissues' blood flow perfusion rate are discussed. We find that the blood perfusion rate of point tissue increases with the intensity of laser acupuncture increasing. After impulse laser acupuncture the point tissue blood perfusion rate increase little, but after continuum laser acupuncture the point tissues blood perfusion rate increase much.
Photobiomodulation, once called biostimulation, has been studied as the mechanism of low intensity laser therapy since 1982, and it has been studied in China since 1987. Chinese therapeutic applications began in low intensity laser acupuncture in 1970s, in intravascular low intensity laser therapy in 1990s, in endonasal low intensity laser therapy in 1998, in high intensity laser acupuncture in 2000, and in laser surgery in 2001. As Chinese therapeutic applications of photobiomodulation were the most widely in the world, the research of photobiomodulation and its therapeutic applications was very progressive in China. Although the specific pathways mediating photobiomodulation were put forward and studied by foreign experts such as Karu et al, the non-specific pathways were put forward for the first time and were also studied very deeply by Chinese experts such as Liu TCY et al. Moreover, basic research of intravascular low intensity laser therapy, such as in vitro blood research and animal model research, was also very progressive in China.
We establish, for the first time, a simulation model for dealing with the second-harmonic signals under a microscope through a tissue-like turbid medium, based on the Monte Carlo method. With this model, the angle-resolved distribution and the signal level of second-harmonic light through a slab of the turbid medium are demonstrated and the effects of the thickness (d) of the turbid medium, the numerical aperture (NA) of the objective as well as the size () of the scatterers forming the turbid medium are explored. Simulation results reveal that the use of a small objective NA results in a narrow angle distribution but strong second-harmonic signals. A turbid medium consisting of large scattering particles has a strong influence on the angle distribution and the signal level , which results in a low penetration limit for second-harmonic signals made up of ballistic photons. It is approximately 30 µm in our situation.
We evaluated the effects of light emitting diode(LED λ 632.8nm; power 4.0mw)applied directly to the colon on the experimental ulcerative colitis. 34 rats were divided into 3 groups, which was LED treatment group (n=12), model group (n=12), and normal control group (n=10). Given glacial acetic acid (5%) intra-anally so as to be replicated the rat model of ulcerative colitis. LED irradiation was used to curative group, with 30min each time, once per day. The period of treatment was one week. Then the activity of superoxide dismutase (SOD) and content of malondi-aldehyde (MDA) in the blood plasma were detected and the histopathological study in Colonic tissue was performed. The degree of the Colonic tissue injury in curative group was not as significant as that in the model group. Comparing with model group, the Content of MDA in LED curative group was reductive and the activity of SOD was increased significantly. We concluded that the LED irradiation can protect colonic mucosa from acetic acid induced damage in rats and the effects may be related to the photobiomodulation of LED.
Temperature is a long established indicator of health. With the advancement of clinical medicine in thermal disease diagnostics, understanding the thermal life phenomena and temperature behavior has become increasingly important. The biological effects of human exposure to low-intensity laser irradiation thermo-therapy, the best established are those due to elevation of tissue temperature. Bio-heat equations (BHEs) are necessary for predicting tissue temperature during thermal treatment. To prevent harmful levels of heating, restrictions have been proposed on low-intensity laser irradiation as the external spatial heating. In this paper, considering the different properties for the pathological tissue and the normal tissue, using a numerical method to solve the Pennes’ bio-heat equation, we analyzed theoretically the relationship between the temperature distribution and external spatial heating during low-intensity laser irradiation. The effects of the thermal parameters such as the heat conductivity, blood perfusion rate, and metabolic rate of the tissues on the temperature distribution were discussed. The results can be used to predicted different effects on the temperature variation and distribution, the thermal damage distribution and the thermal damage volume etc. The results are also useful in optimizing the therapeutic parameters for improved low-intensity laser irradiation treatments and for better understanding the thermal life phenomena in living tissues.