• Archives of Plastic Surgery
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• 제37권5호
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• pp.712-716
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• 2010

Purpose: Extensive lumbosacral defects after removal of spinal tumors have a high risk of wound healing problems. Therefore it is an effective reconstructive strategy to provide preemptive soft tissue coverage at the time of initial spinal surgery, especially when there is an instrument exposure. For soft tissue reconstruction of a lumbosacral defect, a variation of the gluteal flap is the first-line choice. However, the musculocutaneous flap or muscle flap that is conventionally used, has many disadvantages. It damages gluteus muscle and causes functional disturbance in ambulation, has a short pedicle which limits areas of coverage, and can damage perforators, limiting further surgery that is usually necessary in spinal tumor patients. In this article, we present the superior gluteal artery perforator turn-over flap that reconstructs complex lumbosacral defects successfully, especially one that has instrument exposure, without damaging the ambulatory function of the patient. Methods: A 67 year old man presented with sacral sarcoma. Sacralectomy with L5 corpectomy was performed and resulted in a $15{\times}8\;cm$ sized complex soft tissue defect in the lumbosacral area. There was no defect in the skin. Sacral stabilization with alloplastic fibular bone graft and reconstruction plate was done and the instruments were exposed through the wound. A $18{\times}8\;cm$ sized superior gluteal artery perforator flap was designed based on the superior gluteal artery perforator and deepithelized. It was turned over 180 degrees into the lumbosacral dead space. Soft tissue from both sides of the wound was approximated over the flap and this provided in double padding over the instrument. Results: No complications such as hematoma, flap necrosis, or infection occurred. Until three months after the resection, functional disturbances in walking were not observed. The postoperative magnetic resonance imaging scan shows the flap volume was well maintained over the instrument. Conclusion: This superior gluteal artery perforator turn-over flap, a modification of the conventional superior gluteal artery perforator flap, is a simple method that enabled the successful reconstruction of a lumbosacral defect with instrument exposure without affecting ambulatory function.

• Biomolecules & Therapeutics
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• 제11권2호
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• pp.99-108
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• 2003

Background: There is abundance of studies on the decrease in body fat through limited calorie intake or exercise; however, studies focusing simultaneously on functional foods and exercise are rare. This study was aimed to identify the effects of combination of a functional beverage and exercise on body composition and biochemical metabolic profiles. Method: Eighty-one healthy volunteers (69 females aged 19 to 50 years and 12 males aged 19 to 55 years), who maintained their body weight stable with 23 or higher in BMI (kg/$m^2$) and 25% or higher body fat for the last three months, were recruited in the study through written advertisement. All the subjects gave their informed consent, and the study was conducted in accordance with the Declaration of Helsinki. The study design was a randomized double-blind placebo-controlled parallel group design. All participants were given 12-week programed-exercise, which was performed 3 times a week. One bottle (100 ml) of test (Garcinia cambogia 300 mg, L-carnitine 20 mg, Soy peptide 1,000 mg) or placebo solution was given daily 30 min before each session of programed-exercise. BMI (body mass index), %fat, local fat amount (visceral and mid-thigh), waist circumference, skin fold thickness and some biochemical metabolic parameters like glucose, insulin and free fatty acids, etc in the blood were measured and compared before and after 12-week intervention within groups as well as between groups according to the protocol Results: Twenty six volunteers were dropped out and fifty five volunteers completed the study. At the end of 4, 8, and 12 weeks, approximately 1.98%, 3.00% and 3.50% losses of initial body weight were observed, respectively, in the test group (P<0.01), and 0.29, % ,0.74%, 1.60%, respectively, in the placebo group (P>0.05). BMI changed by 2.40%, 3.41% and 4.46%, respectively, in the test group, and 0.38%, 0.95% and 1.75%, respectively, in the placebo group, at each period of time. The reductions of body weight and BMI were significantly higher in the test group than in the placebo group at each period of time (P<0.05). Conclusions: It is thought that the combination of functional beverage, which contains mostly garcinia cambogia, L-carnitine, and soy peptide, and exercise have synergy effects on reducing body fat.

• Journal of Welding and Joining
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• 제33권5호
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• pp.26-30
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• 2015

Hastelloy X in this study was applied in jet engine F-15 air fighter as shroud to isolate the engine from outer skin. After 15 years operation at elevated temperature the mechanical properties decreased gradually due to the precipitation of continues second phases in the grain boundaries and precipitated inside the grain. The crack happened at the edge of the shroud due to the thermal and mechanical stress from jet engine. Selective TEM analysis found that the grain boundaries consist of $M_{23}C_6$ carbide, $M_6$ Ccarbide and small percentage of sigma(${\sigma}$) phase. Furthermore, it was confirmed the nano size of ${\sigma}$ and miu (${\mu}$) phase inside the grain. In this study, it was investigated the microstructure of the degraded shroud component and HAZ of repair welded shroud. In the HAZ, it was observed the dissolution of the $M_{23}C_6$ carbides and smaller precipitates, the migration of the undissolved larger $M_{23}C_6$ carbide and $M_6$ Ccarbide. It is also observed the liquation due to the simply melt of the segregated precipitates in the grain boundaries. Interestingly, the segregated second phases which simply melt in the grain boundaries more easily happened at higher heat input welding condition. High temperature tensile test was done at $300^{\circ}C$, $700^{\circ}C$ and $900^{\circ}C$. It was obtained that the toughness of welded sample is lower compare to the non-welded sample. The solution heat treatment at $1170^{\circ}C$ for 5 minutes was suggested to obtain a better mechanical properties of the shroud. The high cycle fatigue number of the repair welded shroud shows a much lower compare to the shroud. In addition, the high cycle fatigue number at room temperature after solution heat treatment was almost double compare to the before solution heat treatment under 420-500MPa stress amplitude. However, the high cycle fatigue number of repaired welded sample was shown a much lower compare to the non- welded shroud and solution treated shroud. One of the main reasons to decrease the tensile strength and the high cycle fatigue properties of the repair welded shroud is the formation of the liquid phase in HAZ.

• Nutrition Research and Practice
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• 제7권2호
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• pp.115-121
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• 2013

We examined the characteristics of food allergy prevalence and suggested the basis of dietary guidelines for patients with food allergies and atopic dermatitis. A total of 2,417 patients were enrolled in this study. Each subject underwent a skin prick test as well as serum immunoglobulin E (IgE) measurement. A double-blind, placebo-controlled food challenge was conducted using milk, eggs, wheat, and soybeans, and an oral food challenge was performed using beef, pork, and chicken. Food allergy prevalence was found among 50.7% in patients with atopic dermatitis. Among patients with food allergies (n = 1,225), the prevalence of non-IgE-mediated food allergies, IgE-mediated food allergies, and mixed allergies was discovered in 94.9%, 2.2%, and 2.9% of the patients, respectively. Food allergy prevalence, according to food item, was as follows: eggs = 21.6%, milk = 20.9%, wheat = 11.8%, soybeans = 11.7%, chicken = 11.7%, pork = 8.9% and beef = 9.2%. The total number of reactions to different food items in each patient was also variable at 45.1%, 30.6%, 15.3%, 5.8%, 2.2%, and 1.0% for 1 to 6 reactions, respectively. The most commonly seen combination in patients with two food allergies was eggs and milk. The clinical severity of the reactions observed in the challenge test, in the order of most to least severe, were wheat, beef, soybeans, milk, pork, eggs, and chicken. The minimum and maximum onset times of food allergy reactions were 0.2-24 hrs for wheat, 0.5-48 hrs for beef, 1.0-24 hrs for soybeans, 0.7-24 hrs for milk, 3.0-24 hrs for pork, 0.01-72 hrs for eggs, and 3.0-72 hrs for chicken. In our study, we examined the characteristics of seven popular foods. It will be necessary, however, to study a broader range of foods for the establishment of a dietary guideline. Our results suggest that it may be helpful to identify food allergies in order to improve symptoms in patients with atopic dermatitis.

• 대한관절경학회지
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• 제14권1호
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• pp.49-52
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• 2010

목적: 회전근 개 파열에서의 전외측 도달법을 이용한 소절개 봉합술을 소개하고자 한다. 수술 술기: 전신 마취하에 측와위 자세를 취한 후 후방 삽입구, 전방 삽입구를 이용하여 관절내 병변의 유무를 확인하고, 관절경을 견봉하 공간에 위치시킨 후 외측 삽입구를 이용하여 회전근 개의 파열 형태 및 크기를 파악한 후 관절경하견봉 성형술을 시행한다. 견봉의 전외측 연에서 하방으로 3~4 cm의 피부 절개를 가한 후 전방 및 중간 삼각근의 봉합선을 따라 박리하고 삼각근 견인기를 이용하여 시야를 확보한다. 파열된 건에 견인 봉합을 시행하여 해부학적 복원을 위한 위치를 확인한 후 봉합 나사를 이용하여 일열 혹은 이열 봉합술을 시행한다. 봉합술 후 견봉에서 삼각근이 견열되는 것을 방지하기 위해 1번 흡수봉합사를 이용하여 견봉과 삼각근과의 추가적인 봉합을 시행한다. 결론: 본 술기는 회전근 개의 가장 흔한 파열 부위인 극상건의 전방부에 직접 도달이 가능하고, 전방 및 중간 삼각근 사이로 접근하기 때문에 삽입구 연장 도달법에 비해 비교적 적은 견인으로도 시야를 확보할 수 있으며 전방으로는 견갑하건의 상부와 후방으로는 극하건까지 도달할 수 있는 유용한 술식으로 생각된다.

• 한국전산구조공학회논문집
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• 제22권5호
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• pp.463-474
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• 2009

기존에 설치되어 있는 구조물의 양면대칭 패치보강은 항상 면내거동만을 유발하나 시공상 어려움이 있다. 반면에 일면 패치보강의 경우 인장력의 증가에 따라 중립축의 위치가 대칭이 아니므로 휨에 대한 강성도가 증가하게 되며, 결과적으로 적층판의 휨을 심화시키게 된다. 이 연구에서는 일면 패치보강된 적층판의 두께방향은 물론이고 원공주위의 응력집중계수를 산정하기 위해 p-수렴 완전층별모델을 제안하였다. 가정된 변위장의 정의를 위해, 임의의 층에서 변위-변형률 관계와 3차원 구성방정식은 2차원 및 3차원 계층적 형상함수의 조합이 사용된다. 원형경계의 기하형상을 나타내기 위해 초유한사상기법이 사용되며, 다른 외삽법을 사용하지 않고 각 층마다 절점에서의 응력값을 직접적으로 얻기위해 가우스-로바토 수치 적분이 수행되었다. 제안된 모델의 정확도와 단순성은 기존의 3차원 유한요소해석과 실험에 의해 구해진 결과들과의 비교를 통해 검증되었다. 또한 정사각형, 원형, 고리형 형상의 다양한 패치보강에 따른 휨효과를 조사하였다.

• 대한조선학회논문집
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• 제29권4호
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• pp.152-172
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• 1992

대파고 파랑중을 항해하는 선박은 큰 선체 운동으로 인하여 수면하 단면 형상이 시시각각 크게 변하므로 자유 표면 조건, 물체 표면 조건의 비선형성에 의한 비선형 유체력의 영향이 무시될 수 없게 된다. 경우에 따라서는 선저가 파면으로부터 충격력을 받는 슬래밍 현상과 선수가 파도를 뒤집어 쓰는 청파 현상등과 같은 충격적 유체력이 선체에 가해지는 등 복잡한 문제가 발생하게 된다. 본 연구에서는 선체를 가변 단면보의 탄성체로 이상화하여 파랑중 선체 거동을 박육 단면보 이론에 의해 정식화하고 파랑 하중으로는 수면하 단면 형상 변화에 따른 비선형 유체력과 momentum slamming이론을 이용한 유체 충격력을 고려하여 대파고 파랑 중 탄성체인 선체의 응답을 추정하는 해석 기법을 개발하여 이를 기존의 실험결과와 비교 그 타당성을 확인하고, 이의 응용으로 본 기법에 의하여 4만톤급 정유 운반선에 적용하여 정면파 및 사파중에서 파고, 파장, 선속을 파라미터로 한 수치 계산을 수행하고 여러가지 파라미터 변화에 대한 선체 구조의 동적 강도 응답 특성을 계통적으로 분석하여 보았다. 본 연구에서 개발된 동적강도 해석법은 대파고 중에서 유체력의 비선형성 및 유체 충격력까지 고려한 해석기법이므로 신구조 방식 선박에 대한 직접 설계법의 확립 뿐만 아니라 슬래밍 등에 의한 선체 절손 사고의 원인 규명에도 유용하게 적용할 수 있을 것으로 사료된다.

• 생명과학회지
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• 제21권11호
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• pp.1573-1578
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• 2011

Silibinin은 milk thistle에서 분리된 주된 생리활성 성분으로 강력한 항산화제, 항암활성에 대해서 보고되어 있다. 하지만 항암활성에 대한 정확한 기전에 대해서는 밝혀져 있지 않다. 본 연구에서는 인간 전립선 암세포주인 PC-3 세포를 이용하여 세포사멸의 기전을 조사하였다. MTT assay를 통해 세포독성을 확인하였고, PI 염색을 통해 세포주기를 확인하고, Annexin-V/PI 염색을 통한 세포사멸을 확인하였다. 뿐만 아니라 western blot을 이용하여 세포주기 및 세포사멸에 관련된 단백질 발현 정도를 확인하였다. 본 연구의 결과에서 silibinin은 인간 전립선 암세포주인 PC-3 세포에서 세포주기관련 단백질의 발현을 조절하여 세포주기 진행을 억제함으로써 세포사멸을 유도 함을 알 수 있었다.

• 대한조선학회지
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• 제22권1호
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• pp.45-53
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• 1985

For the analysis of vertical vibrations of a ship's hull, the Timoshenko beam analogy is accepted up to seven or eight-node modes provided that the system parameters are properly calculated. As to the shear coefficient, it has been a common practice to apply the strain energy method or the projected area method. The theoretical objection to the former is that it ignores lateral contraction due to Poisson's ratio, and the latter is of extreme simplifications. Recently, Cowper's and Stephen's shear coefficient formulas have drawn ship vibration analysts' attentions because these formulas, derivation of which are based on an integrations of the equations of three-dimensional elasticity, take Poisson's ratio into account. Providing computer programs for calculation of the shear coefficient of ship sections modeled as thin-walked multicell sections by each of the forementioned methods, the authors calculated natural vibration characteristics of a bulk carrier and of a container ship by the transfer matrix method using shear coefficients obtained by each of the methods, and discussed the results in comparision. The major conclusions resulted from this investigation are as follows: (1) The shear coefficients taking account of the effects of Poisson's ratio, Cowper's $K_c$ and Stephen's $K_s$, result in higher values of about 10% in maximum as compared with the shear coefficient $K_o$ based on the conventional strain energy methods; (a) $K_c/K_o{\cong}1.05\;and\;K_s/K_o{\cong}1.10$ for ships having single skin side-shell such as a bulk carrier. (b) $K_c/K_o{\cong}1.02\;and\;K_s/K_o{\cong}1.05$ for ships having longitudinally through bulkheads and/or double side-shells in the portion of the cargo hod such as a container carrier. (2) The distributions of the effective shear area along the ship's hull based on each of $K_o,\;K_c\;and\;K_s$ are similar each another except the both end portions. (3) Natural frequencies and mode shapes of the hull based on each of $K_c\;and\;K_s$ are of small differences as compared each other. (4) In cases of using $K_c\;or\;K_s$ in ship vibration analysis, it is also desirable to have the bending rigidity be corrected according to the effective breadth concept. And then, natural frequencies and mode shapes calculated with the bending rigidity corrected in the above and with each of $K_o,\;K_c\;and\;K_s$ result in small differences as compared each another. (5) Referring to those mentioned in the above (3) and (4) and to the full-scale experimental results reported by Asmussen et al.[17], and considering laboursome to prepare the computer input data, the following suggestions can safely be made; (a) Use of $K_o$ in ship vibration analysis is appropriate in practical senses. (b) Use of $K_c$ is appropriate even for detailed vibration analysis of a ship's hull. (6) The effective shear area based on the projected area method is acceptable for the two-node mode.

• 멤브레인
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• 제21권4호
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• pp.389-397
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• 2011

본 연구에서는 용액 캐스팅법을 이용하여 각기 다른 함량의 VMT가 첨가된 SPAES/VMT 복합막이 제조되었다. SPAES 매트릭스 내의 VMT입자 분산은 전자주사현미경으로 관찰된 평균분포에 의해 확인되었다. 1 wt%보다 적은 함량을 포함한 복합막은 고분자 매트릭스 내에 좋은 분산성을 나타내어 막의 상부층과 하부층에 매끈한 표면을 가졌다. 복합막의 함수율은 온도가 증가함에 따라 급격하게 증가되었으며 VMT는 높은 이온교환능력으로 인하여 강한 수분친화도를 가짐으로 인해 높은 모든 흡착된 수분은 bound water인 것으로 확인하였다. VMT의 함량이 1 wt%보다 적게 첨가된 복합막에서 증가된 이온전도도와 낮아진 메탄올 투과도를 확인할 수 있었다. 모든 복합막 중에서 SPAES/VMT 1.0 wt% 복합막은 선택도 측면에서 가장 뛰어난 연료전지 성능을 가졌으며 Nafion 112과 비교하여 두배 이상 우수한 값을 나타내었다. 이것은 SPAES/VMT 1.0 wt% 복합막이 직접메탄올 연료전지의 구동을 위한 가장 우수한 조건이 될것이라 사료된다.