• Current Optics and Photonics
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• v.4 no.1
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• pp.31-43
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• 2020

The feasibility of the application of terahertz electromagnetic waves in the diagnosis of prostate cancer was examined. Four samples of incomplete cancerous prostatic paraffin-embedded tissues were examined using terahertz spectral imaging (TPI) system and the results obtained by comparing the absorption coefficient and refractive index of prostate tumor, normal prostate tissue and smooth muscle from one of the paraffin tissue masses examined were reported. Three hundred and sixty cases of absorption coefficients from one of the paraffin tissues examined were used as raw data to classify these three tissues using the Principal Component Analysis (PCA) and Least Squares Support Vector Machine (LS-SVM). An excellent classification with an accuracy of 92.22% in the prediction set was achieved. Using the distribution information of THz reflection signal intensity from sample surface and absorption coefficient of the sample, an attempt was made to use the TPI system to identify the boundaries of the different tissues involved (prostate tumors, normal and smooth muscles). The location of three identified regions in the terahertz images (frequency domain slice absorption coefficient imaging, 1.2 THz) were compared with those obtained from the histopathologic examination. The tissue tumor region had a distinctively visible color and could well be distinguished from other tissue regions in terahertz images. Results indicate that a THz spectroscopy imaging system can be efficiently used in conjunction with the proposed advanced computer-based mathematical analysis method to identify tumor regions in the paraffin tissue mass of prostate cancer.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.471-476
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• 2015

Purpose: We have analyzed the transmittance distribution of various ocular lenses using local transmittance microscope to investigate the optical homogeneity of the lens. Methods: The local transmittance of the laser which is focused on the surface of the spectacle lens was measured by using the photo-detector, lock-in amplifier and motorized-stage. 25 multi-coated lenses with non-tinted of 5 groups and 45 multicoated lenses with tinted of 9 groups were analyzed as a sample respectively. Results: Average and deviation of local transmittance for nontinted lenses were measured almost uniformly with various refractive index and coating. However, deviation of transmittance of for tinted lenses was analyzed as about 3.7 times larger than that of non-tinted lenses. Inhomogeneity of local transmittance of for tinted lenses was also analyzed as about 3.1 times larger than that of non-tinted lenses. Conclusions: We could analyze that standard deviation of transmittance and inhomogeneity of local transmittance of for tinted lenses is larger than that of non-tinted lenses using the local transmittance microscope. These analysis using local transmittance microscope can be utilized as a way to evaluate lens performance and improve optical homogeneity.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.523-529
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• 2023

In order to achieve excellent spatial resolution, very small scintillation pixels are used in detectors of positron emission tomography for small animals. However, by using these very small scintillation pixels, scintillation pixels at the edge of the array may overlap in a flood image. To solve this problem, a light guide capable of changing the distribution of light was used. Depending on the material of the light guide, the light spreading tendency is different, and accordingly, the presence or absence of overlapping is different depending on the material of the light guide used. In this study, instead of the conventional glass light guide, a detector using the same material as the scintillation pixel was designed. A scintillator light guide has a higher refractive index than a glass light guide, so the light spread is different. Flood images were acquired to evaluate the degree of separation of the scintillation pixels at the edge of the detector using the two light guides. The degree of separation was evaluated by calculating the distance between the center and the spatial resolution of the image of two scintillation pixels at the edge of the obtained flood image. As a result, when the scintillator light guide was used, better spatial resolution was shown, and the distance between centers of scintillation pixels was wider. When a detector is constructed using a scintillator light guide instead of a conventional glass light guide, it is possible to use a smaller scintillation pixel, thereby securing better spatial resolution.

• Applied Biological Chemistry
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• v.6
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• pp.15-24
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• 1965

The mackerels, Scomber japonicus (HOUTTYN), for this study were caught by purse sein net in Korea. In this paper, the seasonal variations of the oil content and Vitamin A concentration in oil in different parts of the mackerel, the distribution of the Vitamin A of viscera of that and physical and chemical constants of oil were discussed. The results are summarized as follows: 1. In the beginning of June, the liver weight increased rapidly and reached the maximum. In this period, the gonad weight was also maximum. It seemed that this phenomenon has influenced on the nutritional and physiological aspects of the spawning stage. 2. The Vitamin A concentration of liver oil reached the maximum value in the middle of July. In the most case, it was proportinate to the oil content in liver inversely. 3. The Vitamin A concentration of pyloric caeca oil reached the maximum Value in the late of July. It showed the tendency of being proportionate to the oil content in pyloric caeca inversely. And the Vitamin A concentration of intestine oil reached maximum value in the beginning of July. 4. The distribution average ratio of Vitamin A in liver, pyloric caeca, intestine, stomach and contents of stomach and gonad to the total Vitamin A in whole viscera were 60.8, 29.4, 5.7, 2.2, and 1.9 percentage. The seasonal variation of the distribution of Vitamin A in pyloric caeca to the amount of total Vitamin A in whole viscera was proportionate to that of liver inversely. 5. It seemed that there were no any corelation between the Vitamin A content and seasonal variation of the physical and chemical constants of viscera oil. But when the Vitamin A concentration was high, the refractive index, the amount of unsaponifiable matter and iodine value of viscera oil were also high. 6. On the extracting vitamin oil of viscera of mackerel, it is the most suitable period from the end of May to the middle of October. The liver, pyloric caeca and intestine of mackerel are valuable and the other parts of vicera are worthless as vitamin oil resources. It is probable that the whole viscera oil could also be utilized as vitamin-rich oil, if it were concentrated.