• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권1호
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• pp.13-17
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• 2013

Purpose: This study evaluated the capability of bone formation of silk fibroin particles coated with hydroxyapatites (HA/SF), as bone graft material when put into the calvarial defect of rats. Methods: Twenty Sprague Dawley rats were used for this study and round shaped defects were formed in the center of parietal bones (diameter: 8.0 mm). The defect was filled with (1) HA/SF (experimental group), or (2) left as a vacant space (control group). The animals were sacrificed at 4 or 8 weeks, postoperatively. The specimens were decalcified and stained with Masson's trichrome for histomorphometric analysis. Results: The average of new bone formation was $33.18{\pm}3.10%$ in the experimental group and $20.49{\pm}5.79%$ in the control group at 4 weeks postoperatively. That was $42.52{\pm}7.74%$ in the experimental group and $25.50{\pm}7.31%$ in the control group at 8 weeks postoperatively. The difference between the groups was significantly higher at both 4 weeks and 8 weeks postoperatively (P<0.05). Conclusion: The rat calvarial defect was successfully repaired by HA/SF graft. The HA/SF graft showed more new bone formation compared with the unfilled control.

• 대한토목학회논문집
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• 제32권6A호
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• pp.411-418
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• 2012

이 연구에서는 수치해석 실험을 통하여, 원주방향 관통균열을 갖는 원통형 쉘의 패치보강 전후의 거동에 대한 평가와 다양한 변수에 따른 패치보강 효과를 분석하였다. 해석 모델의 신뢰성을 높이기 위해, h-법 및 p-법에 기초한 모델링, 두 가지 방법이 동시에 고려되었다. 또한 선형탄성파괴역학 개념에 기초하여 에너지 방출률을 산정하기 위해, 등가영역적분법 및 가상균열확장법이 고려되었다. 해석 예제로서, 먼저 연구에서 수행된 h-법 및 p-법 유한요소 모델을 검증하기 위해, 패치 보강전의 인장력을 받는 관통 균열이 있는 쉘 구조물이 해석되었으며, 해석 결과값들과 여러 참고문헌 값들이 비교되었다. 그리고 패치 보강된 원통형 쉘 시스템에서의 접착제 두께, 접착제 전단탄성계수, 패치 두께, 패치 재료, 균열 길이 등의 여러 설계 변수에 대한 민감도 해석이 수행되었다.

• 대한예방한의학회지
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• 제4권1호
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• pp.81-90
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• 2000

This study was conducted to investigate the antitoxic component in methanol extract of Houttuynia cordata $T_{HUNB}$. The results were as follows: Generally, detoxication effects by Houttuynia cordata $T_{HUNB}$ methanol extract increased in proportion to the methanol extract concentrations. When 40 mg/kg dosage of Houttuynia cordata $T_{HUNB}$ methanol extract was administrated, it showed the highest antitoxic effects in metallothionein induction. After the methanol extract treatment. Body weights increased in proportion to methanol extract concentrations. However, after 3 weeks, the body weight decreased insignificantly. From the above results, these results suggest that the methanol extract of Houttuynia cordata $T_{HUNB}$ increased metallothionein concentration and decreased the toxicity of cadmium in rats.

• 생약학회지
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• 제25권2호
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• pp.153-159
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• 1994

The studies were conducted to investigate the inflammation, gastric ulcer, analgesic and homothrmic of experimental animals by KYUNG OK-KO water extract and drink, which is a traditional preparation in Korea. 1. It was exhibited significantly anti-inflammatory effects to acute inflammation on carragennan edema, and preventive and therapeutic effects to chronic inflammation on Freund's complete adjuvant in rats(100, 200, 400 mg/kg). Especially, preventive effect of KYUNG OK-KO water extracts at doses of 100, 200, 400 mg/kg in rats were showed dose-dependantly. 2. Aspirin-induced gastric ulcer were remarkably repaired by all experimental groups of KYUNG OK-KO water extracts. 3. The number of writing syndromes by acetic acid induced also were decreased which MPI's test was increased by tail flick apparatus in mice remarkably, all doses of water extracts(100, 200, 400 mg/kg) and dose-dependantly. 4. Aminopyrine-induced homothermic effects of KYUNG OK-KO water extract(100, 200, 400mg/kg) and drink (0.7, 1.4, 2.1 ml/kg) were significantly evaluated dose-dependantly in 400 mg/kg, 2.1 ml/kg groups.

• 토지주택연구
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• 제7권2호
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• pp.113-119
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• 2016

주택의 양적 공급보다는 질적 개선 등 유지보수가 중요해지고 있는 시점에서 본 논문은 현재 주택개보수 정책의 현안을 정리하고 이에 따른 개선방향을 제시하고자 한다. 2015년 주거급여의 개편과 더불어 저소득층에 대한 주택개보수가 확대되었으며, 각 부처에서 개별적으로 진행하는 개보수사업도 지속되고 있다. 현행 개보수정책은 공통적으로 대상자 선정을 기준으로 개별 주택에 대한 보수가 이루어지고 있으며, 주거급여의 수선유지급여는 임차가구를 제외한 자가 수급가구에 한정하고 있다. 향후 개보수정책은 구체화된 목표 설정과 활용문제를 검토하여야 하며, 주거급여는 임차가구와 소득 기준 대상자 확대를 고려하여야 한다. 또한 개별주택이 아닌 여러 주택에 대한 동시 개보수, 시공업체 선정방식의 개선, 유지보수업의 품질확보와 선진화 등을 추진할 필요가 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.161-164
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• 2008

구조물은 사용연한 경과에 따른 노후화 및 용도 변경 등에 의한 보수.보강시 널리 행해지는 부착공법 중 탄소섬유, 아라미드섬유, 유리섬유 등을 이용한 섬유보강 폴리머(Fiber-reinforced polymer,FRP) 보강공법은 섬유 자체의 내화학성, 내구성과 우수한 시공성 등의 장점을 지니고 있다. 현재 FRP 부착공법을 이용한 보강설계 및 보강구조물의 내력 계산시, 콘크리트 부재와의 부착력을 완전부착으로 가정하고 있으나 콘크리트 구조물이 내부적 요인 및 외부 환경요인에 의해 열화될 경우 내력저하 및 1차적인 표면부 열화로 인한 FRP 부착면적의 손실발생이 우려된다. 하게 된다. 따라서 노후화에 따라 내력저하를 보이는 철근콘크리트 구조물에 FRP 보강시 열화에 따른 FRP 보강부재와 콘크리트 모재 간의 부착력 손실에 관한 연구가 필요하며, 본 연구에서는 환경적 요인에 의해 열화되는 철근콘크리트 부재의 파괴양상 및 구조성능과 FRP 보강부재와 콘크리트 모재와의 부착성능 저하현상을 분석하기 위하여 동결융해에 따른 CFRP 쉬트의 보강성능을 실험적으로 규명하고자 한다.

• 한방재활의학과학회지
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• 제26권3호
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• pp.1-15
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• 2016

Objectives This study was designed to evaluate the anti-inflammatory effects of Seungseup-tang (SST) on the monosodium iodoacetate (MIA)-induced osteoarthritis rats. Methods Osteoarthritis was induced by injection of MIA ($50{\mu}l$ with 80 mg/ml) into knee joint cavity of rats. Rats were divided into 4 groups (normal group, control group, indomethacin treated group, SST treated group, each n=6). Normal group was not injected with MIA and taken normal diet. Control group was injected with MIA and taken with distilled water. Indomethacin treated group was injected with MIA and taken indomethacin 5 mg/kg by oral administration. SST treated group was injected with MIA and taken SST 200 mg/kg by oral administration. We examined the weight-bearing ability of hind paw, biomarkers related to oxidative stress in serum, inflammatory proteins and inflammatory mediators and cytokines. Moreover, histopathological examination of knee joint structure was also performed by Hematoxylin & Eosin (H&E), Safranin-O staining method. Results In the present study, SST treated group showed a similar inhibitory effects alike indomethacin treated group, in most of the studied parameters of inflammation. The increased oxidative stress biomarker such as reactive oxygen species (ROS) and peroxy nitrite ($ONOO^-$) in the serum were reduced with SST. Especially, the level of $ONOO^-$ compared with control group significantly suppressed. Also, the expression of inflammatory mediators and cytokines induced by nuclear factor-kappa B (NF-${\kappa}B$) activation was modulated through inhibition of IkBa phosphorlation. In addition, histological analysis revealed that cartilage damage by MIA repaired markedly in SST treated group. Conclusions According to the results, Seungseup-tang may be effective for preventing the progression of osteoarthritis.

• 한국해안·해양공학회논문집
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• 제20권1호
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• pp.42-48
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• 2008

신뢰성 해석을 이용하여 해수면 상승에 따른 경사식 해안 구조물의 안정성 및 기능성을 정량적으로 평가할 수 있는 위험도 평가 시스템을 개발하였다. 안정성 평가를 위한 피복재의 해석에서는 피복재의 대표입경과 제체의 경사, 기능성 평가를 위한 처오름의 해석에서는 제체의 경사와 마루높이를 변화시키면서 해수면 상승 전 후의 파괴확률이 정량적으로 산정 되었다. 위험도 평가 시스템을 임의의 단면에 적용하여 해수면 상승에 따라 안정성과 기능성이 얼마나 감소하는지를 정확히 판정할 수 있었다. 따라서 본 연구의 결과는 해수면 상승 후에도 전과 동일한 안정성 및 기능성을 회복하기 위해서 어떤 변수들을 보수 보강해야 하는지, 또한 새로운 구조물 설계 시 설계변수들을 얼마나 강화해야 하는지의 기초 지표로 이용될 수 있다.

• Steel and Composite Structures
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• 제17권5호
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• pp.601-621
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• 2014

Repairing and strengthening structural members by bonding composite materials have received a considerable attention in recent years. The major problem when using bonded FRP or steel plates to strengthen existing structures is the high interfacial stresses that may be built up near the plate ends which lead to premature failure of the structure. As a result, many researchers have developed several analytical methods to predict the interface performance of bonded repairs under various types of loading. In this paper, a numerical solution using finite - difference method (FDM) is used to calculate the interfacial stress distribution in beams strengthened with FRP plate having a tapered ends under thermal loading. Different thinning profiles are investigated since the later can significantly reduce the stress concentration. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both beam and bonded plate. The shear correction factor for I-section beams is also included in the solution. Numerical results from the present analysis are presented to demonstrate the advantages of use the tapers in design of strengthened beams.

• Clinics in Shoulder and Elbow
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• 제25권1호
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• pp.5-14
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• 2022

Background: The purpose of this study was to verify the effect of protocatechuic acid (PCA) on tendon healing and fatty degeneration in a chronic rotator cuff model. Methods: Twenty-eight Sprague-Dawley male rats were randomly allocated into two groups: Saline+repair (SR) and PCA+repair (PR). The right shoulder was used for experimental interventions, and the left served as a control. PCA (30 mg/kg/day) was administered intraperitoneally at the site of infraspinatus tendon detachment in rats in the PR group, and the same volume of saline was administered to the same site in the SR group. The torn tendon was repaired 4 weeks after infraspinatus detachment. Four weeks after repair, hematoxylin and eosin (H&E), S100, and CD68 stains were performed to evaluate the degree of fatty degeneration and H&E and Masson trichrome stains were performed to assess tendon healing. Superoxide dismutase (SOD) was measured to test the efficacy of PCA as an antioxidant. Results: Results from histological evaluation indicated that SOD and CD68 levels at the musculotendinous region and collagen fiber parallel to the orientation at the tendon-to-bone junction were not significantly different between the SR and PR groups. The mean load-to-failure of the PR group (20.32±9.37 N) was higher than that of the SR group (16.44±6.90 N), although this difference was not statistically significant (p=0.395). The SOD activity in the operative side infraspinatus muscle of the PR group was higher than that of the SR group, but the difference was not statistically significant (p=0.053). Conclusions: The use of PCA could improve tendon healing and decrease fatty degeneration after rotator cuff repair.