• The Korean Journal of Food And Nutrition
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• v.28 no.6
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• pp.941-946
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• 2015

Photoaging is the main extrinsic aging factor that is induced due to UVB. Many studies have revealed that application of hyaluronic acid to the skin is effective in healing photoaging. However, the effect of hyaluronic acid through oral administration is unclear. The aim of this research was to investigate the effect on skin photoaging after oral administration of hyaluronic acid. During a ten week study, hyaluronic acid was fed to hairless mice, which were illuminated by UV radiation. After ten weeks, wrinkle indicator and histological changes were determined. Compared with the control group, the sample group had a decrease in wrinkle depth, thickness, and number. Especially, the HA 160 mg/kg group had a similar value of wrinkle depth ($19.44{\pm}0.75{\mu}m$), number ($654.00{\pm}98.34$), and thickness ($1.35{\pm}0.08mm$), when compared with the RA (retinoic acid) group ($19.28{\pm}0.95{\mu}m$, $653.57{\pm}83.54$, and $1.34{\pm}0.07mm$ respectively). Also, the treated group showed improved elastosis and decreased collagen degradation resulting from UV irradiation. Thus, we can conclude that hyaluronic acid has a positive effect in improving skin photoaging induced by UV radiation. Hyaluronic acid therefore has the potential to be an ingredient in skin health function foods.

• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.15-27
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• 2004

In this study, skin friction evaluation methods developed f3r deep foundation system were investigated and a method that can properly evaluate the skin friction of large size pneumatic caisson was proposed. Especially, based on Hong Won-Pyo's method, new technique (Kn parameter method) was suggested for estimation of the skin friction. The $\lambda$ method used widely to pile foundation was also investigated fur the applicability of estimation of the skin friction of large size pneumatic caisson. To do this, the data measured from the pneumatic caissons installed as a substructure of main tower in the suspension bridge part of Youngjong Grand Bridge were utilized. The data show that the skin friction is proportional to the rate of sinking, and the skin friction distribution with depth is similar to parabolic type rather straight line, which is a type generally observed in pile foundation. The skin frictions predicted by the Kn and $\lambda$ methods were plotted with the measured data for comparisons. It is cleary shown that the skin frictions estimated by the proposed Kn parameter method are well matched with the measured data. That is, for the large size pneumatic caisson having wide base, the new technique developed from Hong Won-Pyo's method is more suitable for estimation of the skin friction rather than the $\lambda$ method.

• Journal of Radiation Protection and Research
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• v.40 no.1
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• pp.65-72
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• 2015

The basic concepts of radiation-induced skin damage have been established, the biological mechanism has not been studied. In this study, we have examined the effects of gamma rays on skin injury and cyclooxygenase(COX)-2 expression. Gamma irradiation induced clinicopathological changes in a dose- and time-dependent manner in mini-pig skin. The histological changes were consistent with the changes in gross appearance at 12 weeks after irradiation. After three days' irradiation, apoptotic cells in the basal layer were found more frequently in irradiated skin than in normal skin, with the magnitude of the effect being dose-dependent. The thickness of the epidermis transiently increased 3 days after irradiation, and then gradually decreased, although changes in the epithelial thickness of the irradiated field were not observed with irradiation doses over 50 Gy. In the epithelium, there was an initial degenerative phase, during which the rate of basal cell depletion was dependent on the radiation dose (20-70 Gy). One week after irradiation, COX-2 expression was mostly limited to the basal cell layer and was scattered across these cells. High COX-2 expression was detected throughout the full depth of the skin after irradiation. The COX-2 protein is upregulated after irradiation in mini-pig skin. These histological changes associated with radiation exposure dose cause the increased COX-2 expression in a dose-dependent fashion.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.29-36
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• 1983

The treatment of tumors along curved surfaces with stationary electron beams using cone collimation may lead to non-uniform dose distributions due to a varying air gap between the cone surface and patient. For large tumors, more than one port may have to be used in irradiation of the chest wall, often leading to regions of high or low dose at the junction of the adjacent ports. Electron-beam arc therapy may elimination many of these fixed port problems. When treating breast tumors with electrons, the energy of the internal mammary port is usually higher than that of the chest wall port. Bolus is used to increase the skin dose or limit the range of the electrons. We invertiaged the effect of various arc beam parameters in the isodose distributions, and combined into a single arc port for adjacent fixed ports of different electron beam eneries. The higher fixed port energy would be used as the arc beam energy while the beam penetration in the lower energy region would be controlled by a proper thickness of bolus. We obtained the results of following: 1. It is more uniform dose distribution of electron to use rotation than stationary irradiation. 2. Increasing isocenter depth on arc irradiation, increased depth of maximum dose, reduction in surface dose and an increasing penetration of the linear portion of the curve. 3. The deeper penetration of the depth dose curve and higher X-ray background for the smaller field sized. 4. If the isocenter depth increase, the field effect is small. 5. The decreasing arc beam penetration with decreasing isocenter depth and the isocenter depth effect appears at a greater depth as the energy increases. 6. The addition of bolus produces a shift in the penetration that is the same for all depths leaving the shape of the curves unchanged. 7. Lead strips 5 mm thick were placed at both ends of the arc to produce a rapid dose drop-off.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.76-85
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• 2010

In general, anesthetic depth is evaluated by experience of anesthesiologist based on the changes of blood pressure and pulse rate. So it is difficult to guarantee the accuracy in evaluation of anesthetic depth. The efforts to develop the objective index for evaluation of anesthetic depth were continued but there was few progression in this area. Heart rate variability provides much information of autonomic activity of cardiovascular system and almost all anesthetics depress the autonomic activity. Novel monitoring system which can simply and exactly analyze the autonomic activity of cardiovascular system will provide important information for evaluation of anesthetic depth. We investigated the anesthetic depth as following 7 stages. These are pre-anesthesia, induction, skin incision, before extubation, after extubation, Post-anesthesia. In this study, temporal, frequency and chaos analysis method were used to analyze the HRV time series from electrocardiogram signal. There were NN10-NN50, mean, SDNN and RMS parameter in the temporal method. In the frequency method, there are LF and HF and LF/HF ratio, 1/f noise, alphal and alpha2 of DFA analysis parameter. In the chaos analysis, there are CD, entropy and LPE. Chaos analysis method was valuable to estimate the anesthetic depth compared with temporal and frequency method. Because human body was involved the choastic character.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.192-203
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• 2004

The AA5182/polypropylene/AA5182 (AA/PP/AA) sandwich sheets have been developed for the application for automotive body panels in the future light weight vehicles with significant weight reduction. It has been reported that the 5182 aluminum sheet shows Luders band because of dissolved Mg atoms that causes fabrication process problem, especially surface roughness. The examination of serration behavior has been made after the tensile deformation of the AA/PP/AA sandwich sheets as well as that of the 5182 aluminum skin at room and elevated temperatures. All sandwich sheets and the 5182 aluminum skin showed serration phenomena on their flow curves. However, the magnitude of the serration was significantly diminished in the sandwich sheet with the high volume fraction of the polypropylene core. According to the results of the surface roughness analysis after the tensile test, the sandwich sheet evidently showed lower Luders band depth than the 5182 aluminum skin. Strain rate sensitivity, m-value, of the 5182 aluminum skin was -0.006. By attaching this skin with polypropylene core which has relatively large positive value, 0.050, m-value of the sandwich sheets was changed to the positive value. The serration reduction of the sandwich sheets was quantitatively investigated in the point of the effect on the polypropylene core thickness variation, that on the strain rate sensitivity. It was found that the serration reduction degree from the experimental results of the sandwich sheet was higher than that from the calculated values by the rule of mixture based on volume fraction of the skins and the core.

• Archives of Plastic Surgery
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• v.47 no.6
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• pp.613-618
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• 2020

The surgical treatment of extensive urethral strictures remains a controversial topic; although techniques have evolved, there is still no definite method of choice. Since 1968, when Orandi presented an original technique for one-stage urethroplasty using a penile skin flap, the Orandi technique has become the most prevalently used one-stage procedure for anterior urethral strictures. We present a 20-year follow-up experience with one-stage reconstruction of long urethral strictures using a longitudinal ventral tubed flap of penile skin, with some important technical changes to Orandi's original technique to overcome the deficient vascularity caused by periurethral scar tissue. In 1997, a 55-year-old male patient complained of severe voiding difficulty and a weak urinary stream because of transurethral resection of the prostate due to benign prostatic hyperplasia. Another 47-year-old male patient had the same problem due to self-removal of a Foley catheter in 2002. In both patients, a urethrogram demonstrated extensive strictures involving the long segment of the anterior urethra. A rectangular skin flap on the ventral surface of the penis was used considering the appropriate length, diameter, and depth of the neourethra. The modified Orandi flap provided a pedicled strip of penile skin measuring an average of 8 cm. The mean duration of follow-up was 20.5 years. A long-term evaluation revealed stable performance characteristics without any complications.

• Journal of Haehwa Medicine
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• v.24 no.2
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• pp.25-34
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• 2016

Objectives : Historical study on application of Kyungohkgo, one of the most popular tonic medicine, and suggestion of modernistic method through it Methods : Investigated effect and its range of Kyungohkgo in original texts of Korean medicine, and researched studies on medical action and treatment effect of Kyungohkgo nowaday. Results : Kyungohkgo has "replenish essence and marrow(補精益髓)" as a major effect, and various original text suggested that Kyungohkgo can be used as antioxidant tonic medicine, treatment of respiratory disease like tuberculosis and medicine for bone disease controling hormone. Several research about these subjects has been progressed recently. However, the most of these researches is not an in-depth study about virtues in original texts, but deduced from effects of Kyungohkgo, and there are some studies experimented with Kyungohkgo that has not followed its own formula. Conclusions : It is required to discuss new application based on understanding effect and is range of Kyungohkgo. It could be thought that using for skin disease based on t theory of "lung presides skin and hair", chronic pulmonary disease based on treatment of cough(咳嗽), and disease of uterine and bone based on "replenish essence and marrow(補精益髓)".

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.7
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• pp.620-628
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• 2005

The blinds in the intermediate space are installed to block the direct solar radiation. As the blind divide the airflow of intermediate space into two, thermal performance of Double-Skin Facade (DSF) are affected by the blind position. Therefore blind position should be planed with careful consideration in order to maximize the thermal performance of DSF. In this study, CFD was peformed to analyze the effect of blind position in multistory-type DSF in variation of other DSF elements. The simulation results showed that the case with narrow depth of intermediate space and outlet on upper side of outer-facade, it is profitable to place blind as close as possible to the outer-facade. In the other cases, the blind should maintain 0.15 m distance from outer-facade.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.558-561
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• 2001

SIP(Soil cement Injected Precast pile) that inserts a precast pile after injecting a cement paste into a boring has been applied rapidly through the change of construction circumstances. But there isnt any logical equation of a bearing capacity fitted to SIP yet. So Meyerhof equation has mainly been used to predict a bearing capacity in a design stage instead. But it has shortcomings such as lack of confidence because it has derived not from a theory but from an experience obtained from the result of SPT (Standard Penetration Test) and because a penetration depth tends to be deeper by an excessive design that depends on an end bearing capacity of a pile more than a skin frictional resistance. In this study, thereupon, a direct shear test in the laboratory was performed to both SM and SC soils in variable conditions to verify skin friction properties for the purpose of presenting some reasons capable of reducing penetration depths. Through the tests, soil to soil of SM in cohesion, rough panel to soil of SM in friction angle and soil to soil of SM in shear strength tended to be high. And a shear strength increased as its total unit weight increased in all cases.