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Objective: To investigate the effects on ribbon synapse of inner hair cells after superpulsed CO2 laser-assisted cochleostomy in SD rats., Methods: Eighteen SD rats were randomly divided into laser-assisted surgery groups (2 W group and 5 W group), sham-operated group and control group. Ten of those were performed a cochleostomy using superpulsed CO2 laser with a corresponding power. Auditory brainstem responses (ABR) were measured pre-and postoperatively. The ribbon synapses at apical and middle cochlear turns were observed under laser scanning confocal microscope and then were quantified with 3ds Max software., Results: The postoperative ABR thresholds of the 2 W and 5 W groups were larger than the preoperative case (t = -5.65, P < 0.01; t = -4.97, P < 0.01). The synapse number at the middle turn decreased significantly in 5 W group (F = 17.15, P < 0.01), while no significant changes were noted at the apical turn (P > 0.05). There was no statistical difference in 2 W group (P > 0.05)., Conclusions: The superpulsed CO2 laser-assisted cochleostomy with high-power is accompanied by a synaptic injury, while no obvious effects after the low-power laser surgery, which might be a safe strategy to preform cochleostomy.

Characteristics and differences of temperature and back-scattered light intensity in different depths of 0.2, 0.4, 0.6, 0.8 and 1 mm for both human Hegu acupoint and non-acupoint tissue irradiated by 808 nm diode laser at the different power of 15, 25 and 35 mW were studied. The temperature and the back-scattered light intensity in different depths of 0.2, 0.4, 0.6, 0.8 and 1 mm for human Hegu acupoint and non-acupoint tissue were measured by using the infrared thermography and optical coherence tomography. The result shows few differences in the temperature and the back-scattered light intensity of human Hegu acupoint and non-acupoint tissue before irradiation. The temperature and back-scattered light intensity of Hegu acupoint and the non-acupoint after irradiation were significantly higher, and the temperature and back-scattered light intensity of Hegu acupoint significantly were higher than the non-acupoint areas. At 0-40 min after the irradiation, the temperature and back-scattered light intensity of Hegu acupoint and the non-acupoint area will fluctuate and gradually decrease with the passage of time. From the results above, it is clearly seen that Hegu acupoint is different from non-acupoint both in the back-scattered light intensity and temperature after irradiation, and Hegu acupoint is more sensitive to laser irradiation than non-acupoint tissue.

The aim of this in vitro study was to evaluate the effects of low level laser irradiation on the proliferation of HeLa cells using 405 nm diode laser, 514 nm argon laser, 633 nm He-Ne laser, or 785 nm diode laser, The cells were seeded on 96-well microplates for 24 h in 5% fetal bovine serum containing medium, then irradiated with the laser at dose of 100 and 1 000 J x m(-2), respectively. At the time point of 24, 48, 72 h after irradiation, cell viability was assessed by MTT assay. The results show that 405, 633 and 785 nm laser irradiation induces wavelength-dependent and time-dependent proliferation. 633 nm laser irradiation results in a stimulatory proliferation effect that is most significant, whereas 514 nm laser irradiation produces little increase in cell proliferation. Low level laser irradiation increases cell proliferation in a dose-dependent manner. 1 000 J x m(-2) laser irradiation is more effective in increasing cell proliferation than 100 J x m(-2) laser irradiation using 405 nm diode laser, 633 nm He-Ne laser, or 785 nm diode laser, but not as effective as using 514 nm argon laser.

The changes of skin tissue reflectance spectroscopy before and after being treated with the optical clearing agents of three different types of optical clearing within the wavelength rang of 400-1 000 nm, and the degree of changes in reflectance spectroscopy of each group skin during 0-60 min at 580 nm in vivo were real-time dynamically researched. The reflectance spectroscopy of skin tissue before and after being dealt by the optical clearing agents of glycerol, glucose and propylene glycol was measured using a USB-4000 fiber spectrophotometer at 0, 10, 20, 30, 40, 50 and 60 min. The results showed that the reflectance spectral intensity was distinctly decreased, but the reflectance was significantly increased gradually with the time prolonged. However, different optical clearing agents have different clearing progress. The relative decrease of reflectance of palm skin tissue before and after being dealt by the optical agents of 40% glycerol, 40% glucose and 40% propylene glycol during 10, 20, 30, 40, 50 and 60 min at the wavelength 580 nm is 5%, 7%, 9%, 10%, 11% and 12%, 9%, 13%, 16%, 19%, 21% and 22%, and 14%, 22%, 29%, 32%, 34% and 35%, respectively. The significant improvement in light transmittance and enhancement of light penetration through tissue was demonstrated for all solutions. The effect and processes of optical clearing of skin tissue is not only closely related to the choosing of the clearing agent type, but also related to the treatment time with the skin tissue. The clearing progress of different type optical clearing agent showed the order of 40% propylene glycol, 40% glucose and 40% glycerol.

In order to find a non-invasive way to improve the efficacy of skin optical clearing with topically applied optical clearing agents, the authors researched the changes of reflectance spectroscopy of skin tissues before and after being dealt by low-frequency ultrasound and osmotic active chemical agents within the wavelength range of 400-860 nm, and the degree of changes in reflectance spectroscopy of each group skin during 0-15 min and 15-30 min at 580 nm. The measurements were performed using a AvaSpec-2048 optical fiber spectrometer with integrating-sphere setup. The results of measurements showed that there were a few changes of the reflectance spectroscopy of skin tissues in the control group (Group 1) (The skin tissue was dealt with nothing. ) during the whole observation; But in the Group 2 (The skin tissue was dealt with only low-frequency ultrasound), it was found that the reflectance of the skin tissue showed a significant increase comparing 15 min with 0 min, but the changes in reflectance of the tissues slowly restored the original form following the longer time since the ultrasound stopping; There was also a very fast changes in reflectance of the skins in the Group 3 (the skin were dealt with only 80% glycerol) compared with that in the Group 1. The authors also found that there was a very distinct decrease in the reflectance of skin tissues dealt with both low-frequency ultrasound and 80% glycerol group (Group 4), especially during the 0-15 min, and its speed was 4.0 times that of the Group 1 and 2. 3 times that of Group 3 (During 0-15 min, the reflectance of skin tissues in the Group 1 decreased 1.896%; the reflectance of skin tissue in the Group 3 decreased 3.316%; the reflectance of skin tissues in the Group 4 decreased 7.551%). From the above results, it can be clearly seen that the low-frequency ultrasound and 80% glycerol not only have synergistic effect on optical clearing of skin tissue in vitro, but can change the optical clearing of the skin tissue in a short time.

Characteristics and differences of reflectance spectroscopy of human Laogong acupoint and non-acupoint tissues before and after irradiation by different power of laser were studied in the spectral range from 400 to 1 000 nm. A wavelength 808 nm semiconductor laser was used for irradiation at the power of 20, 50 and 100 mW for ten minutes. Reflectance spectra of human Laogong acupoint and non-acupoint tissues were measured by using an AvaSpec-2048 optical fiber spectroscopy with an integrating sphere attachment. The result shows that before irradiation the shape of the reflectance spectra of Laogong acupoint and non-acupoint is similar, they have the same troughs at 423, 544, 577 and 980 nm, and the reflectance for Laogong acupoint and non-acupoint at these wavelengths is 17.1%, 26.1%, 25.9% and 35.0%, and 17.1%, 27.6%, 28.1% and 36.5% respectively. But from 475 to 1 000 nm, the reflectance of Laogong acupoint is smaller than that of non-acupoint. After being irradiated by semiconductor laser at the power of 20, 50 and 100 mW, there is a very significant decrease in the reflectance of Laogong acupoint compared to that before irradiation, and the higher the power, the lower the reflectance. But there is just a small decrease in the reflectance for non-acupoint compared to that before irradiation. From the above results, it is clearly seen that Laogong acupoint is different from non-acupoint on reflectance spectroscopy, and Laogong acupoint is more sensitive to laser irradiation than non-acupoint tissue.

Spectral characteristics of normal female breast samples in the 350-850 nm wavelength range were measured using a UV/Vis/NIR spectrophotometer system with integrating sphere attachment for measuring the diffuse reflectance and transmittance. The optical properties of normal breast tissue in vitro were obtained by the inverse adding doubling method. And then the optical penetration depths in this spectral range were analyzed based on the principle of tissue optics. The results show that the reduced scattering coefficient of normal female breast tissue is significantly higher than the absorption coefficient in the 350-850 nm wavelength range. The reduced scattering coefficient decreases with the wavelength increment. It reaches maximum at shorter wavelengths with a decrease at longer wavelengths and ranges from 9.731 mm(-1) at 350 nm to 1.476 mm(-1) at 850 nm. The absorption coefficient of normal breast tissue is about from 0.798 mm(-1) at 350 nm to 0.102 mm(-1) at 850 nm. The maximal and minimal values are at 350 nm and 850 nm respectively. An absorption peak for the normal breast tissue is at 410 nm of wavelength with the value of 0.506 mm(-1), which belongs to hemoglobin. The absorption coefficient remains relatively constant when the wavelength is longer than 600 nm. The optical penetration depth increases with the wavelength increment and ranges about from 0.199 mm at 350 nm to 1.439 mm at 850 nm. Deep penetration depth noted in normal breast samples, especially at longer wavelengths, reflects the weak absorption and reduced scattering at these wavelengths. The calculated optical parameters of normal breast samples by the inverse adding doubling method agree well with the Monte Carlo simulations. This study may be useful for breast optical biopsy or the optical diagnosis of breast diseases.

Differential diagnosis for epithelial tissues of normal human gastric, undifferentiation gastric adenocarcinoma, gastric squamous cell carcinomas, and poorly differentiated gastric adenocarcinoma were studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 250 to 650 nm, pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the DNA absorption bands at 260 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 68.5% (p < 0.05), 146.5% (p < 0.05), 282.4% (p < 0.05), 32.4% (p < 0.05), 56.00 (p < 0.05) and 83.0% (p < 0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the protein absorption bands at 280 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 86.8% (p < 0.05), 262.9% (p < 0.05), 660.1% (p < 0.05) and 34% (p < 0.05), 72. 2% (p < 0.05), 113.5% (p < 0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the carotene absorption bands at 480 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 59.5% (p < 0.05), 73% (p < 0.05), 258.9% (p < 0.05), 118.7% (p < 0.05), 139.2% (p < 0.05), and 324. 6% (p < 0.05) respectively. It is obvious that pathological changes of gastric epithelial tissues induced that there were significant changes in the contents of the DNA, protein and beta-carotene of gastric epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive the optical biopsy for gastric cancer and provides a useful reference.

Differential diagnosis of human colon adenoma was studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 590 to 1 064 nm pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the DNA absorption bands at 260 nm between normal and adenomatous colon epithelial tissues, and the differences were 218% (p < 0.05) and 68.5% (p < 0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the protein absorption bands at 280 nm between normal and adenomatous colon epithelial tissues, and the differences were 208% (p < 0.05) and 59.0% (p < 0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the beta-carotene absorption bands at 480 nm between normal and adenomatous colon epithelial tissues, and the differences were 41.7% (p < 0.05) and 32.9% (p < 0.05) respectively. Obviously, pathological changes of colon epithelial tissues were induced so that there were significant changes in the contents of the DNA, protein and beta-carotene of colon epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive optical biopsy of colon adenoma, and provides a useful reference.

Raman spectroscopy has shown its potential and advantages in detecting molecular changes associated with tissue pathology, which makes it possible to diagnose with optical methods non-invasively and real-time. A compact and rapid near-infrared (NIR)Raman system was developed using 785 nm diode laser, volume phase technology (VPT)holographic grating system and NIR intensified charge-coupled device (CCD)with a specially designed Raman fibre probe which can effectively reduce the interference of fluorescence and Rayleigh scattering, maximize the ability of Raman collection as well as correct the image aberration of a planar grating diffraction. Adopting this method, signal-to-noise ratio has been greatly improved and human tissue signals can be acquired in a short time. Raman signals from fat and musculature of fresh pork were measured and referenced for further optimization, then Raman spectra of nasopharyngeal carcinoma in vitro and the effect of storage time on them were measured in 1-5 s and discussed. The sensitivities and performance of the system will be further enhanced and more Raman data will be acquired and compared between normal and cancerous nasopharyngeal tissue, expecting to discover the statistical characteristics, which will benefit the diagnosis and treatment of early nasopharyngeal carcinoma or other tumors.

Based on the analysis of skin structure, and the production mechanism of fluorescence and reflectance spectra, six-layer optical models for skin of different blood content in both upper blood plexus and deep blood plexus were developed, and Monte Carlo simulation was made. The result shows that (1) Both fluorescence and reflectance spectra could reflect the change of blood content in skin tissue; (2) The impact of blood content in upper blood plexus on skin spectra intensity is large, while the impact of blood content in deep blood plexus on skin spectra intensity is small; (3) Fluorescence and reflectance spectra could be used to detect or analyze change of blood content in skin tissue, especially to test the treatment and tune of dermatosis with plexus or blood pathological changes in upper dermis.

A double-integrating-spheres and IAD method were used to study the differences in the optical penetration depths (OPDs) and light attenuation (LA) native and coagulated human liver tumors and liver tissues at the wavelengths of 680, 720, 780, 810, 850 and 890 nm of Ti: Sapphire laser. The results of measurement showed that the OPDs for native and coagulated human liver tumors and liver tissues at six different wavelengths obviously increase with increasing laser wavelength, the OPDs of coagulated human liver tumors and liver tissues at six different wavelengths were significantly smaller than that of native human liver tumors and liver tissues at the same wavelength respectively (P<0.05), and the OPDs of native and coagulated human liver tumors at six different wavelengths were significantly bigger than that of native and coagulated human liver tissues at the same wavelength respectively (P<0.05). The LA for native and coagulated human liver tumors and liver tissues at six different wavelengths obviously decreases with increasing laser wavelength, and the LA for coagulated human liver tumors and liver tissues at six different wavelengths is significantly bigger than that for native human liver tumors and liver tissues at the same wavelength respectively (P<0.05). The LA for native and coagulated human liver tumors at six different wavelengths is significantly bigger than that for native and coagulated human liver tissue at the same wavelength respectively (P<0.05).