• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.204-210
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• 2013

The patients who had been operated total mastectomy are different from general women in their breasts thickness due to breast surgery. As a result, digital chest image from total mastectomy patients will be different attenuation. The main objective for this study is to show that a proper Ion chamber standard combination measuring MTF which is objective basis for Digital image, when be x-ray for total mastectomy patient. We have designed the unique number that shown Left is 1, Right is 2, Center is 3 and have put the edge phantom on detector ion chamber. Lastly, we have obtained experiment images. The evaluations of all image quality have measured by 50% MTF of spatial resolution and absorption dose using Matlab(R2007a). The result showed that average exposure condition, MTF value, absorption dose for 1+3 and 2+3 combinations were 2.745 mAs, 1.925 lp/mm, 0.688 mGy. Consequently, that showed high MTF, DQE and low dose than other combinations. Therefore, a proper changes of ion chambers are able to improve image quality and to reduce radiation exposure when be X-ray for total mastectomy patients. Also, it will be possible to standard for application chamber combination and utilization on clinical detection.

• Korean Journal of Veterinary Service
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• v.36 no.1
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• pp.45-52
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• 2013

The purpose of the present study is to determine whether Schisandra chinensis (SC) has a protective effect on high fat diet (HFD)-induced fatty liver including hepatic lipid accumulation in rats. The HFD-induced obese rats were weighed after SC extracts were administered through the gastrointestinal tract at a concentration of 250 mg/kg b.w/day for 5 weeks. After 5 weeks, all of the rats on a high fat-diet were 36.5% heavier compared with normal controls. In contrast, rats on a high-fat diet supplemented with SC were 23.5% lighter than rats fed only a high-fat diet. Although there was no significant difference in food intake among the groups during the experimental diet period, the body weight gain of the SC group was significantly lower than the weights of the HFD groups. SC treatment slightly decreased the liver weight. Reduction of hepatic TBARS contents by SC was observed in rats fed a diet containing SC, and antioxidant activity was markedly increased in HFD＋SC group compared to those of HFD group in liver. Moreover, total-lipid and triglyceride contents in the liver of groups fed a diet containing SC were significantly lower compared to those of the HFD group. High fat feeding elevated liver cholesterol concentration, but the addition of SC to the HFD rats resulted in the significant decrease in liver cholesterol. In histological observation of liver tissues, the hepatocytes of HFD rats showed a typical fatty liver morphology showing numerous lipid droplets in cytoplasm, whereas administration of SC reduced the size and numbers of lipid droplets. These results clearly demonstrated the attenuation of SC on nonalcoholic fatty liver induced by obese rats fed HFD.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.443-451
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• 2017

Mammography is commonly used for screening early breast cancer. However, mammographic images, which depend on the physical properties of breast components, are limited to provide information about whether a lesion is malignant or benign. Although a dual-energy subtraction technique decomposes a certain material from a mixture, it increases radiation dose and degrades the accuracy of material decomposition. In this study, we simulated a breast phantom using attenuation characteristics, and we proposed a technique to enable the accurate material decomposition by applying weighting factors for the dual-energy mammography based on a photon-counting detector using a Monte Carlo simulation tool. We also evaluated the contrast and noise of simulated breast images for validating the proposed technique. As a result, the contrast for a malignant tumor in the dual-energy weighted subtraction technique was 0.98 and 1.06 times similar than those in the general mammography and dual-energy subtraction techniques, respectively. However the contrast between malignant and benign tumors dramatically increased 13.54 times due to the low contrast of a benign tumor. Therefore, the proposed technique can increase the material decomposition accuracy for malignant tumor and improve the diagnostic accuracy of mammography.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.487-494
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• 2020

The distance between the source and the detector, the diameter of the detector, and the volume effect of the radiation source result in a change in solid angle at the detector entrance, which affects the determination of detection efficiency by causing a difference in path length within the detector. A typical analysis method for calculating solid angles was useful only for a source (⁶⁰Co) with a simple geometric structure, so in this experiment, the distance between the detector and the source was measured by switching on for up to 25 cm with the reference point of window cap 0.5 cm. In addition, 450 and 1000 ㎖ Marinelli beaker of standard volumetric sources were closely adhered to the detector. For circular point sources co-axial with the detector, the change in the solid angle to the distance from the detector window is equal to half the square radius of the source versus the square radius of the detector, if the resulting relationship of the calculation analysis results in the detector being less than the radius of the source. Since the solid angular difference is 0.5 the result of Monte Carlo is acceptable. The relationship between detector and source distance is shown. Solid angles have been verified to decrease rapidly with distance. Measurement and simulation results for a volumetric source show a difference of ±1.01% from a distance of 0 cm and less than 4 % when the distance is reduced to 5 and 10 cm. It can be seen that the longer distance, the smaller efficiency angle, and the exponential increase in attenuation as the energy decreases, is reflected in the calculation of efficiency. Thus, the detection efficiency has proved sufficient for the use of solid angle and Monte Carlo codes.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.551-556
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• 2004

The purpose of this study was to suggest a systematic and scientific method for measurement of children's growth development, in which the accuracy of existing diagnosis method has not been concretely examined yet. The most popular method for diagnosis of children's growth is to analyze the opening degree of growth plate in each joint by X-ray image. However, X-ray method has some disadvantages; it is impossible to measure the diagnosis of growth periodically and repeatedly due to the radiation problem. Hence, this study introduced a profile analysis and the algorithm of analyzing the image of growth plate with the BUA(Broadband Ultrasound Attenuation) of calcaneus, to verify the possibility of alternative ultrasonic method harmless to human body. We obtained the images of growth plate in proximal tibiae, phalanges, and calcanei of 269 children (7∼16 years old) with X-ray. And the image of growth plate in calcanei was also obtained front those children with ultrasound. The results showed that the time of the opening degree of growth plate in each joint was almost consistent between X-ray and ultrasonic images. Also, the images of growth plate measured by X-ray and ultrasound showed the high correlation. Therefore, it is expected that the algorithm of ultrasonic profile analysis introduced in this study can replace the existing X-ray method to measure the growth plate correctly.

• Journal of Life Science
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• v.29 no.11
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• pp.1200-1207
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• 2019

Ultraviolet radiation exposure is a major cause of extrinsic skin aging, which leads to skin hyperpigmentation. Loganin, a major iridoid glycoside obtained from Corni fructus, has anti-inflammatory, anti-diabetic, and neuroprotective effects. In this study, we investigated the mechanisms underlying the anti-melanogenic effects of loganin in B16F10 melanocytes treated with ${\alpha}$-melanocyte stimulating hormone (${\alpha}-MSH$) and 3-isobutyl-1-methylxanthine (IBMX). Anti-melanogenic activity was measured by treating cells with loganin at concentrations between 1 and $20{\mu}m$. Cell viability assays confirmed that doses of loganin up to $20{\mu}m$ were not cytotoxic. Loganin significantly and dose-dependently decreased intracellular melanin production. We also investigated potential molecular signaling pathways for the anti-melanogenesis effects of loganin. Western blotting showed that treatment with ${\alpha}-MSH$ and IBMX increased the phosphorylation of cAMP response element-binding protein (CREB) and the gene expressions of microphthalmia-associated transcription factor (MITF) and tyrosinase. Addition of loganin suppressed these increases, while promoting the phosphorylation of extracellular signal regulated kinase (ERK) and the anti-melanogenesis response. Our data therefore indicated that loganin could attenuate the increased melanin synthesis induced by ${\alpha}-MSH$ and IBMX treatment of B16F10 melanocytes. This attenuation appears to occur by downregulation of CREB phosphorylation and MITF and tyrosinase gene expression and upregulation of ERK phosphorylation. These finding suggests that loganin could be a valuable candidate for treatment of skin diseases related to hyperpigmentation.

• The Journal of the Acoustical Society of Korea
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• v.40 no.5
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• pp.408-416
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• 2021

In the ultrasonic dispersion, in order to avoid direct contact of the radiation surface of ultrasonic transducers with a liquid sample, the liquid sample is separated by a glass container and it receives ultrasonic energy through an acoustic medium. The transmission efficiency of the ultrasonic energy in the multi-layered ultrasonic system is an important factor. In this study, we suggested a method that can improve the ultrasonic energy transfer efficiency by using a propylene glycol solution as a liquid matching layer in the multi-layered acoustic system. In this method, a propylene glycol solution was filled between the Langevin-type ultrasonic transducer and the luminol solution and the sonoluminescence phenomena in the luminol solution, which is caused by nonlinear effect of high power ultrasound radiated from the transducer, was examined by using a Photo Multiplier Tube (PMT). The transmission efficiency depending on the concentration of propylene glycol solution was observed, and we can see that as the concentration of the propylene glycol solution increased, the matching effect increased while the acoustic attenuation increased. It was confirmed that there is an optimal concentration compromised these two conflicting conditions, and the optimum concentration of the propylene glycol solution was determined experimentally.