• Nutrition Research and Practice
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• v.15 no.1
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• pp.1-11
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• 2021

BACKGROUND/OBJECTIVES: It is difficult to consistently demonstrate the health effects of soy isoflavones owing to the multitude of factors contributing to their bioavailability. To accurately verify these health effects, dietary isoflavone intake should be measured using a biologically active dose rather than an intake dose. This concept has been expanded to the development of new exposure biomarkers in nutrition research. This review aims to provide an overview of the development of exposure biomarkers and suggest a novel research strategy for identifying the health effects of soy isoflavone intake. MATERIALS/METHODS: We cover recent studies on the health effects of soy isoflavones focusing on isoflavone metabolites as exposure biomarkers. RESULTS: Compared to non-fermented soy foods, fermented soy foods cause an increased concentration of isoflavones in the biofluid immediately following ingestion. The correlation between exposure biomarkers in blood and urine and the food frequency questionnaire was slightly lower than that of corresponding 24-h dietary recalls. Urinary and blood isoflavone levels did not show a consistent association with chronic disease and cancer risk. CONCLUSION: It is crucial to understand the variable bioavailabilities of soy isoflavones, which may affect evaluations of soy isoflavone intake in health and disease. Further studies on the development of valid exposure biomarkers are needed to thoroughly investigate the health effects of isoflavone.

• Transactions of the Society of Information Storage Systems
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• v.6 no.2
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• pp.63-67
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• 2010

Holographic data storage system is one of next generation high density optical memories. Thereby storing multiple data pages using multiplexing method in one spot, we can achieve high store density and fast access time. However, for uniform writing, we must control exposure time properly by the change of writing material characteristics. Many studies have been investigated about exposure time scheduling. However, once it is decided, we cannot change the scheduled time. Therefore, it is hard to obtain uniform data intensity. In this study, we propose exposure time control method using additional red beam as the monitoring signal. Through reconstructed red beam intensity in real time, we can adjust exposure time by the writing condition change. We construct compensation method mathematically and verify the feasibility of proposed method through the experiments.

• Archives of Pharmacal Research
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• v.9 no.3
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• pp.175-181
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• 1986

Four technical grade organophosphate pesticides (Fenitrothion, Fenthion, Dizninon and EPN) were investigated for their effects on the murine immune function. Among the immunotoxicological assay parameters of NIEHS, humoral immune parameter and pathotoxicological indicators were examined in this study. Subchronic exposure of rodents to these pesticides resulted in marked suppression of humoral immune function and moderate histological changes of lymphoid organ any significant alterations of clinical status.

• Proceedings of the KSRS Conference
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• v.1
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• pp.508-511
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• 2006

Generally, stereo pair images are necessary for 3D viewing. In the absence of quality stereo-pair images, it is possible to synthesize a stereo-mate suitable for 3D viewing with a single image and a depth-map. In remote sensing, DEM is usually used as a depth-map. In this paper, LiDAR data was used instead of DEM to make a stereo pair from a single aerial photo. Each LiDAR point was assigned a brightness value from the original single image by registration of the image and LiDAR data. And then, imaginary exposure station and image plane were assumed. Finally, LiDAR points with already-assigned brightness values were back-projected to the imaginary plane for synthesis of a stereo-mate. The imaginary exposure station and image plane were determined to have only a horizontal shift from the original image's exposure station and plane. As a result, the stereo-mate synthesized in this paper fulfilled epipolar geometry and yielded easily-perceivable 3D viewing effect together with the original image. The 3D viewing effect was tested with anaglyph at the end.

• Journal of the Korean Society of Radiology
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• v.10 no.2
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• pp.109-115
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• 2016

Despite of increasing the use of the digital imaging device in the radiology area, the setting on the optimal irradiation conditions are insufficient. In this study, the exposure dose and image quality by exposure condition of digital radiography device were compared. The exposure doses were obtained by adjusting the exposure condition as 5 steps respectively based on the exposure conditions that are currently used of CR and DR radiography devices. The acquired image has been assessed by 20 medical image professors using the assessment method of the Japanese Society for Tuberculosis Prevent. As a result, in the case of the CR system, the better image quality was obtained in the condition of 120 kVp and 1.5 mAs~2.4 mAs (quality score 91~95.5 points) than standard exposure condition(110 kVp, 3.2 mAs, 86 points). And exposure dose was evaluated as low with $61.3{\sim}98.4{\mu}Gy$ than standard condition($105.11{\mu}Gy$). In DR system, however, the image quality score was higher as 97~98.6 points in the lower tube voltage range (112 kVp, 2.4~3.2 mAs) condition than the standard exposure condition (125 kVp, 3.2 mAs, 91 points). In addition, the exposure dose was $61.5-77.2{\mu}Gy$ lower than standard condition($93{\mu}Gy$). In addition, the exposure dose was low as $61.5-77.2{\mu}Gy$ than standard condition($93{\mu}Gy$). With the results of this study, we confirmed that it is possible to reduce the patient exposure dose with the same image quality by adjusting the optimal exposure condition of digital device.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.156-165
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• 2015

Objectives: The purpose of this study was to investigate the possible effects of a gasoline vapor recovery system on personal exposure levels of gasoline vapor constituents including benzene, toluene, ethyl benzene, xylene(BTEX), and methyl tert-butyl ether(MTBE) among gas station workers in a metropolitan area. Methods: Thirty-one gas station workers at ten gas stations in a metropolitan area were selected as subjects for this study. Test method PV2028 as recommended in the OSHA process was used for sampling and analysis. Results: The personal exposure levels of benzene, toluene, ethyl benzene, xylene, MTBE and gasoline vapor in the gas station workers were $0.0018{\pm}0.0069ppm$, $0.0077{\pm}0.0137ppm$, $0.0002{\pm}0.0008ppm$, $0.0016{\pm}0.0084ppm$, $0.2619{\pm}0.3340ppm$, and $1.4940{\pm}1.7984ppm$, respectively. After adjustment for refueling frequency and volume, personal exposure levelswere higher in the gas stations where gasoline vapor recovery systems(Stage II) were not installed, but the results were not statistically significant. Gasoline vapor concentrations showed a positive correlation to the level of MTBE, a gasoline additive. Conclusions: Vapor recovery systems(Stage II) were effective not only in reducing emissions of air pollutants, but also in reducing exposure to hazardous substances among gas station workers. In addition, acorrelation between gasoline vapors and MTBE concentration was confirmed.

• Journal of radiological science and technology
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• v.44 no.3
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• pp.173-181
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• 2021

The purpose of this study was to reduce dose while maintaining image quality during digital radiographic examination of paranasal sinus by using the automatic exposure control (AEC) system. The tube voltage was set as six stages that increased by about 10 kVp to 70 kVp, 81 kVp, 90 kVp, 102 kVp, 109 kVp and 117 kVp. And then the AEC system conditions were consisted of 9 setting environments, that change mode of the sensitivity (S200, S400, S800) and the density (+2.5, 0, -2.5). We measured automatically exposed tube current (mAs) under 54 conditions with combined these, and assessed SNR and PSNR through the acquired images. In addition, four radiologists performed a qualitative assessment of the acquired images for each combination on a five-point scale of the Likert. As a result, the lowest dose and the highest values of SNR and PSNR in images with a qualitative assessment more than 4 point were the AEC control factors of 90 kVp, S800, D2.5. We applied this condition to the clinical trial, it showed an effect of 83.1% reduction in exposure radiation dose (mR). Therefore, AEC system could be used as dose reduction technology if it understood and used related regulatory factors and physical characteristics.

• Journal of radiological science and technology
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• v.45 no.1
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• pp.1-9
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• 2022

In this study, we proposed an image quality control for an automatic exposure control (AEC) of digital radiographic imaging system and tried to analyze the performance of the AEC by various manufacturer. The subjects of the experiment were analyzed for the AEC image quality evaluation using digital radiation generators from four manufacturer such as PHILIPS, GE Healthcare, SAMSUNG Healthcare, DK Medical Solution. We used as materials for the implementation of the image quality evaluation by coins (500 won, KOMSCO, Korea). This study evaluated the performance evaluation of the AEC as image quality and exposure dose (Milliampere-seconds; mAs). The image quality evaluation was tried visual assessment by two radiologic technologists and contrast to noise (CNR) by ImageJ. The exposure dose investigated mAs on digital radiation generators. The radiographic coin images acquired 360 images based on change in the control factors of the AEC, which were kVp, the consistency of field configuration and dominant zone, sensitivity and density. As a result, there was a significant difference in the AEC performance between manufacturer. The CNR by the AEC for each manufacturer showed a difference of up to about 1.9 times. The exposed tube current by the AEC for each manufacturer showed a difference of up to about 5.8 times. It is expected that our proposed evaluation method using coins could be applied as the AEC performance evaluation method in the future.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.247-255
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• 2014

Objectives: We reviewed the CAREX (CARcinogen EXposure) program designed to estimate the prevalence of occupational exposure to carcinogens and summarized the advantages and limitations of this program. Methods: All literature, including reports on CAREX and the use of CAREX, were reviewed. The keyword search term was CAREX. Additional articles were identified from references cited in articles and reviewed. Results: An exposure information system, CAREX was developed based on data from the Finnish Institute of Occupational Health of Finland and from the US. CAREX has been applied in several countries, including in the EU, in order to estimate national exposure patterns to carcinogens. The initial exposure assessment carried out through CAREX was aimed at estimating exposures over the period of 1990-1993. To estimate the number of workers exposed to carcinogens by using CAREX, reference exposure prevalence from Finland and the United States was computed, which was then reviewed and corrected by national experts. Finally the overall number of workers exposed to carcinogens can be estimated. We found that CAREX has been used in a total of 18 countries. No Asian country has used CAREX. Conclusions: CAREX can be applied not only to estimate the number of workers exposed to carcinogens in Korea, but also to identify high-risk industries with workers most exposed to carcinogens.

• Journal of The Korean Astronomical Society
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• v.8 no.1
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• pp.15-23
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• 1975

A new technique of photographic observations is developed for the determination of time of minimum light of eclipsing binary. An instrumental system to accomplish the observation is described. With this instrument the atmospheric extinction coefficients in Seoul are observed, and four times of minimum light for Algol and W UMa are determined.