• 한국식품영양학회지
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• 제28권6호
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• pp.941-946
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• 2015

본 연구에서는 HA에 대하여 UVB로 주름을 유도시킨 hairless mice에게 경구 투여를 하였을 때, 주름 개선에 미치는 영향을 관찰하였다. 쥐는 UV를 쪼여 광노화를 진행하였으며, HA는 UVB에 노출시키기 4주 전부터 투여하여 총 14주 동안 투여하였다. 주름 개선 평가는 replica 제작하여 주름의 길이, 깊이, 개수, 두께로 평가하였다. 또한, 피부의 조직학적 평가를 통해 진피층 내 교원섬유와 탄력섬유의 양과 형태를 관찰하였다. 10주 동안의 HA를 급여하였을 때 주름의 깊이, 두께, 개수를 측정한 주름 개선 평가에서 세 항목 모두 개선되는 결과를 보였다. 특히 HA의 160 mg/kg 농도에서는 주름의 깊이는 $19.44{\pm}0.75{\mu}m$, 주름 수는 $654.00{\pm}98.34$, 주름두께는 $1.35{\pm}0.08mm$로 양성 대조군(RA)의 결과(주름깊이; $19.28{\pm}0.95{\mu}m$, 주름 수; $953.57{\pm}83.54$, 주름두께; $1.34{\pm}0.07mm$)와 비슷한 수치를 나타내며, 우수한 피부 광노화 개선효과를 보였다. 하지만, 주름길이의 결과에서는 유의적 차이를 나타내지 않았다. HA의 섭취로 인한 교원섬유 및 탄력섬유 염색을 통한 조직학적 평가에서는 UV에 의해 밀도가 엉성하고 배열이 불규칙적이던 섬유들이 개선된 것을 관찰할 수 있었다. 이상의 결과로 보아 HA를 경구 투여 시 UV로부터 유도된 광노화 억제 및 피부주름 개선에 효능이 있음을 확인하였다.

• 한국지반공학회논문집
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• 제20권4호
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• pp.15-27
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• 2004

본 연구에서는 현재까지 연구된 깊은 기초의 주면마찰력 산정법에 의해 제안된 방법들을 검토하여 대형기초인 케이슨(우물통)기초에 대하여 주면마찰력을 적절히 산정할 수 있는 산정법을 제시하였다. 특히 홍원표(1987)가 제안안 주면마찰력 산정법을 기본 토대로 하여 새로운 주면마찰력 산정방법(Kn계수법)을 제시하였다. 그리고 깊은기초인 말뚝의 주면마찰력을 합리적으로 산정할 수 있다고 알려진 $\lambda$법을 이용한 케이슨의 주면마찰력 산정에 대해서도 검토하였다. 이를 위해 영종대교 주탑하부구조인 뉴매틱케이슨 기초의 시공시 계측된 주면마찰력 데이터를 이용하였다. 주면마찰력은 침설속도에 비례하며 주면마찰력의 분포양상은 직선분포보다 포물선분포에 가깝다. 저부가 확대되는 대규모 케이슨기초 침설시 발생하는 주면마찰력 산정결과 일반적인 말뚝기초의 주면마찰력과는 상이하다. 제안된 Kn계수법과 $\lambda$법을 각각 사용하여 산정한 케이슨의 주면마찰력을 실제 케이슨의 계측값으로부터 산정한 주면마찰력과 비교한 결과, Kn계수법를 이용하여 산정한 케이슨의 주면마찰력은 $\lambda$법에 의해 산정된 주면마찰력보다 실측값에 훨씬 근접하다. 즉, 저부가 확대된 형상의 대형의 케이슨기초의 주면마찰력을 산정하기에는 홍원표가 제안한 식을 이용한 Kn계수법이 $\lambda$법보다 더 적절한 방법임을 알 수 있다.

• Journal of Radiation Protection and Research
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• 제40권1호
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• pp.65-72
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• 2015

방사선 노출에 따른 피부손상의 기본이론들은 정립되어 있지만, 정확한 기전에 관해서는 알려지지 않은 실정이다. 본 연구에서는 감마선 조사 후 용량 및 시간에 따라 돼지 피부의 장애를 육안 및 조직학적인 변화를 통해 평가하고 cyclooxygenase(COX)-2 발현 정도를 비교하고자 하였다. 미니돼지의 등 쪽 피부에 20-70 Gy 감마선을 국소조사 후 12 주 동안 육안적인 변화를 관찰하고 생검을 통해 조직학적인 변화를 관찰하였다. 방사선 조사 후 피부의 기저세포층에서의 세포자멸사와 표피층의 두께 변화를 평가하였고 COX-2 발현 정도를 면역염색을 통하여 비교하였다. 방사선 조사 후 피부 장애는 용량이 증가할수록 피부손상이 더욱 심하였으며 초기에 발적 소견을 보이다가 50 Gy 이상 조사군에서는 미란과 궤양으로 이어졌다. 조직학적인 변화는 육안적인 소견과 일치하였다. 방사선 조사 후 3일부터 기저세포에서 세포자멸사가 관찰되었으며 기저세포수의 감소가 유발되었으며 이러한 변화는 용량이 증가할수록 더욱 증가하였다. 방사선 조사 후 표피층의 두께는 3일 무렵에 일시적으로 증가하다가 점차 감소하였으며 20, 30, 40 Gy 조사 군에서는 다시 회복되는 소견이 관찰되었으나 50, 70 Gy 조사 군에서는 다시 회복되지 못하고 표피창의 두께 소실을 보였다. 방사선 조사 후 피부에서의 COX-2 발현은 피부손상정도와 일치하게 관찰되었다. 방사선 조사 후 COX-2 발현은 방사선의 용량이 증가할수록 발현이 증가하였고 시간이 증가할수록 증가하였다. 이러한 조직학적인 변화와 함께 방사선 손상을 일으키는 신호전달에 관여하는 COX-2 발현이 방사선조사 용량에 비례하여 증가하며 이러한 단백질의 발현은 피부손상과 관련성이 높은 것으로 사료된다.

• Radiation Oncology Journal
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• 제1권1호
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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.

• 한국전기전자재료학회논문지
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• 제23권1호
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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.

• 한국자동차공학회논문집
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• 제12권3호
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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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• 제47권6호
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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.

• 혜화의학회지
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• 제24권2호
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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)".

• 설비공학논문집
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• 제17권7호
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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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.