• 공업화학
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• 제31권1호
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• pp.13-18
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• 2020

실크의 섬유 고분자 단백질인 피브로인을 사용하여 산화철 나노입자가 내포된 테라그노시스가 가능한 마이크로캡슐을 제조하였다. 열중량 분석으로 산화철의 함량은 4.28%, 자력계로는 5.11%로 측정되었다. 산화철 마이크로캡슐이 첨가된 마우스 섬유아세포 3T3 배양액에서 얻어진 세포 현탁액은 자력에 반응하여 맑게 변하고, 세포는 자석 방향으로 응집하였다. 배양접시 상단에 올려둔 네오디뮴 자석은 세포를 배양액 표면 중심으로 세포를 끌어모았다. 배양액 표면에 모인 세포들은 응집하여 72 h 이후 장축의 길이가 2 mm인 비대칭 타원체인 세포 집합체를 형성하였다. 세포집합체의 바깥층에는 세포들이 상대적으로 크고 서로 모여 치밀한 조직을 형성하였으나, 중심부는 물질전달제한으로 세포의 사멸이 진행되는 것으로 관찰되었다. 바깥층에는 산화철 마이크로캡슐이 자력의 방향으로 체인처럼 일렬로 늘어선 현상도 관찰되었다. 마이크로CT를 이용하여 세포응집체 내부의 산화철이 고루 분포하지 않고 자력 방향으로 비대칭적으로 분포하고 있음을 보였다.

• 한국전산구조공학회논문집
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• 제34권5호
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• pp.293-300
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• 2021

본 논문은 에너지를 실시간으로 저장할 수 있는 저장장치 중 열에너지 저장 콘크리트를 대상으로 재료의 미세구조와 물성(열전도도)의 상관관계를 분석하는 연구를 수행하였다. 에너지 저장 콘크리트의 열전도 성능을 증가시키기 위해 혼화재인 그라파이트(graphite)를 사용하였다. 그라파이트가 시멘트 질량의 10%와 15%를 치환한 시편과 일반 콘크리트(OPC) 시편을 제작하여 그라파이트의 혼입에 따른 미세구조 변화 및 열전도도의 영향을 마이크로 스케일에서 분석하였다. 마이크로-CT를 활용하여 OPC와 그라파이트를 사용한 콘크리트의 공극률을 비교하였으며, 확률함수를 사용하여 미세구조 특성을 정량화하였다. 미세구조 특성 차이가 열전도도에 미치는 영향을 확인하기 위해 3차원 가상 시편을 제작하여 열해석을 수행하였으며, 이를 열평판법을 사용하여 측정한 열전도도 실험 결과와 비교하였다. 열해석 수행 시 그라파이트 재료가 지닌 열전도도 성능을 반영하기 위하여 해석 결과와 실험 결과를 기반으로 고체상의 열전도도를 역해석을 통해 계산하였으며, 그라파이트가 시편의 열전도도에 미치는 영향에 대해 분석하였다.

• 한국지반신소재학회논문집
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• 제17권4호
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• pp.169-177
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• 2018

유리섬유강화폴리에스테르 복합소재는 지중 매설 파이프, 탱크용 구조재, 선체 등 가혹한 환경에서 구조재로 널리 사용되고 있으며, 장기 내수성을 필요로 하는 소재이다. 특히, 물에 잠겨 있을 때 삼투압으로 인하여 겔코트와 복합소재의 박리 등 열화가 진행된다. 본 연구에서는 지중 매설 파이프로 활용되는 GFRP 복합소재의 내구성 향상을 위해 인퓨전(진공성형) 공정으로 UPE (unsaturated polyester) 겔코트 표면 처리한 복합소재를 제작하여, 고온 수침 환경 ($65^{\circ}C$, $75^{\circ}C$, $85^{\circ}C$)에서의 표면 결함 및 크랙 발생과 경도 변화 특성을 확인하였다. 마이크로 CT 단층 촬영을 통하여 수침 온도에 따른 크랙의 침투 깊이를 조사하였으며, $75^{\circ}C$와 $85^{\circ}C$ 조건에서 크랙이 복합소재까지 침투하여 내구성을 저하시키는 것으로 확인되었다. 최초 크랙이 발생하는 지점을 고장시간으로 정의하고 아레니우스식을 활용하여 $23^{\circ}C$ 상온에서의 수명 예측을 실시하였다. 본 연구로 토목, 건축, 해양산업분야 등 겔코트가 적용되는 다양한 산업분야의 신뢰성 평가에 응용될 수 있을 것으로 기대된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.8.1-8.8
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• 2017

Background: For an effective bone graft for reconstruction of the maxillofacial region, an adequate vascular network will be required to supply blood, osteoprogenitor cells, and growth factors. We previously reported that the secretomes of bone marrow-derived mesenchymal stem cells (MSC-CM) contain numerous growth factors such as insulin-like growth factor (IGF)-1, transforming growth factor $(TGF)-{\beta}1$, and vascular endothelial growth factor (VEGF), which can affect the cellular characteristics and behavior of regenerating bone cells. We hypothesized that angiogenesis is an important step for bone regeneration, and VEGF is one of the crucial factors in MSC-CM that would enhance its osteogenic potential. In the present study, we focused on VEGF in MSC-CM and evaluated the angiogenic and osteogenic potentials of MSC-CM for bone regeneration. Methods: Cytokines in MSC-CM were measured by enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs) were cultured with MSC-CM or MSC-CM with anti-VEGF antibody (MSC-CM + anti-VEGF) for neutralization, and tube formation was evaluated. For the evaluation of bone and blood vessel formation with micro-computed tomography (micro-CT) and for the histological and immunohistochemical analyses, a rat calvarial bone defect model was used. Results: The concentrations of IGF-1, VEGF, and $TGF-{\beta}1$ in MSC-CM were $1515.6{\pm}211.8pg/mL$, $465.8{\pm}108.8pg/mL$, and $339.8{\pm}14.4pg/mL$, respectively. Tube formation of HUVECs, bone formation, and blood vessel formation were increased in the MSC-CM group but decreased in the MSC-CM + anti-VEGF group. Histological findings suggested that new bone formation in the entire defect was observed in the MSC-CM group although it was decreased in the MSC-CM + anti-VEGF group. Immunohistochemistry indicated that angiogenesis and migration of endogenous stem cells were much more abundant in the MSC-CM group than in the MSC-CM + anti-VEGF group. Conclusions: VEGF is considered a crucial factor in MSC-CM, and MSC-CM is proposed to be an adequate therapeutic agent for bone regeneration with angiogenesis.

• 디지털융복합연구
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• 제11권9호
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• pp.365-370
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• 2013

Image J 프로그램은 digital image 분석 또는 생명 공학적 분석에 사용되고 있다. 다양한 동물실험 중에서도 마우스 두개골 결손모델(Mouse calvarial defected model)은 조직공학자들에게 대표적으로 사용되고 있는 뼈의 결손모델이다. 이러한 마우스 두개골 결손 모델은 뼈의 재생 또는 새로운 지지체(scaffold)의 재생효과 실험에 사용되고 있다. 마우스 두개골에 지름 4mm의 원형 결손을 만들어 각종 실험재료를 처리하여 파괴된 마우스 두개골 뼈의 재생에 관련하여 측정하는 실험이 주를 이룬다. 실험 후에 마우스를 희생하여 대부분 헤마톡실린과 에오신 염색을 통하여 분석을 하게 된다. 다른 한편으로는 마이크로 시티(u-CT)를 사용하여 정량적인 분석을 한다. 하지만 이는 시간이 오래 걸리고 고가의 비용이 드는 단점이 있다. 이번 실험은 마우스 두개골 결손 모델 시에 프리쉐어 프로그램인 Image J를 통하여 간단하게 마우스 두개골 결손 뼈의 재생량을 2D X-ray 상으로 농도를 측정하여 정량적인 분석을 실행하였다. 결론적으로 Image J를 사용한 농도 분석법은 빠르고 정확하게 뼈의 재생량을 상대적으로 비교함으로써 신생 뼈의 관한 재생 실험자에게 도움을 줄 수 있을 것으로 사료된다.

• 한방재활의학과학회지
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• 제24권1호
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• pp.31-45
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• 2014

Objectives This study intends to clarify how Leejung-tang (here in after reffered to LJT) affect Wistar Rat whose osteoarthritis was induced by MIA. Methods Osteoarthritis was induced into rat by injecting MIA in its knee joint. Rats are divided into a total of 4 groups (n=6). Normal group are not treated at all without inducing osteoarthritis whereas control group were induced for osteoarthritis by MIA and oral medicated with 2 ml of physiological saline per day. Positive comparison group (Indomethacin) was injected with MIA and after 7 days, 2 mg/kg of Indomethacin was medicated. Experimental group (LJT) was injected with MIA and after 7 days that was medicated with 23 mg/kg of LJT. Indomethacin and LJT were oral medicated for each substance a total of 4 weeks with one time per day. After experiments (from 1 week after injection of MIA to 4 weeks elapsed), Hind paw weight bearing ability, Functions of liver and kidney, Serum prostaglandin $E_2$, TNF-${\alpha}$, IL-1${\beta}$, IL-6, Osteocalcin, TIMP-1, MMP-9, LTB4 and amount of cartilage were measured and histopathological variations for knee joint structures were observed. Results 1) Hind paw weight bearing ability of LJT administration group was increased but there was no statistical significance. 2) Functions of liver and kidney were not affected. 3) Serum prostaglandin $E_2$, IL-1${\beta}$, Osteocalcin, MMP-9 were significantly decreased and TNF-$\alpha$, IL-6, TIMP-1, LTB4 were also decreased but there were no statistical significance. 4) In H&E staining and Safranin-O staining, there were small histopathological changes in LJT administration group than control group. 5) In micro CT (computed tomography)-arthrography, cartilage destruction was more suppressed in LJT administration group than control group. Conclusions Based on all results mentioned above, Leejung-tang (LJT) is believed to be meaningful for suppressing the progress of osteoarthritis and its treatments because of its anti-inflammatory effects and alleviation of pain with histopathological effective efficacy.

• 한국재료학회지
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• 제20권6호
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• pp.312-318
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• 2010

Multilayer Poly methyl methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates were fabricated using electrospinning and in vitro investigations were carried out for pre-clinical biocompatibility studies. The initial cellular cytotoxicity of the methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using fibroblast-like L-929 cells. Cellular adhesion and differentiation studies were carried out using osteoblast-like MG-63 cells. As simulated body fluid (SBF) contains the same ionic concentration of body fluid and any bioactive material tends to deposit bone-like apatite on the samples surfaces into the SBF, in vitro bioactivity of the multilayer bone plates were investigated using SBF. We also studied the internal organization and tensile strength of the multilayer PMMA/PVA bone plates using micro-computed topography (${\mu}$-CT) and universal testing instrument (UTI, Korea) respectively. The cellular cytotoxicity study with MTT confirmed that the cellular viability was 78 to 90% which indicates good cyto-compatibility. Scanning electron microscopic findings revealed a good attachment and adhesion phenomenon of MG-63 cells onto the surfaces of the samples. Cellular differentiation studies also showed that osteogenic differentiation was switched on in a timely manner and affirmed along with that of the control group. Bone-like apatite formation on the surfaces was confirmed within 14 days of SBF incubation. Initial organizations of the multilayer PMMA/PVA bone plates were characterized as dense and uniform. The tensile strength of the post-pressing electronspun mat was higher than that of the pre-electronspun mat. These results suggest that a multilayer PMMA/PVA bone plate system is biocompatible, bioactive and a very good alternative bone plate system.

• 동의생리병리학회지
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• 제31권1호
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• pp.46-51
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• 2017

The aim of this study is to investigate anti-arthritis activity using a KV pharmacopuncture. KV pharmacopuncture was inserted at BL40 for 4 weeks to SD-Rat, where arthritis was induced by monosodium iodoacetate (MIA) at 60 mg/ml. MMP-9, CTX II, LTB4, calcitonin and glycosaminoglycan level in serum were measured by ELISA. The cartilage of patella volume was examined and 3-D high-resolution reconstructions of the cartilage of patella were obtained using a Micro-CT system. Also, The histopathological change of knee was observed by H&E and safranin-O staining. Production of MMP-9, CTX II and LTB4 level in serum was decreased, respectively, in comparison with control. The other way, production of calcitonin and glycosaminoglycan level in serum was increased, respectively, in comparison with control. The cartilage of patella volume increased significantly. In addition, the KV group showed a increase in the cartilage volume and proteoglycan. These results may be used a remedy for new korea medicine to ease the symptoms mentioned above.

• 동의생리병리학회지
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• 제27권2호
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• pp.212-224
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• 2013

This study intends to clarify how Sayeok-tang(here in after reffered to SYT) affect C57BL/10 mice whose osteoarthritis was induced by papain. Osteoarthritis was induced by injecting papain in the knee joint of 3 groups(n=6) of mice. Normal group was non-treatment group and was not injected papain, whereas control mice were orally administered with $200{\mu}{\ell}$ of physiological saline. Positive comparison group was medicated with 100 mg/kg of Joins$^{(R)}$ mixed with $200{\mu}{\ell}$ of physiological saline. Experimental group was medicated with 400 mg/kg of SYT mixed with $200{\mu}{\ell}$ of physiological saline. Both Positive and experimental comparison groups were orally medicated once per day for 4 weeks. After the experiment, the functions of liver and kidney, inflammation cytokine values within serum, degree of revelation for inflammation cytokine genes, immune cells within blood, metabolism of arachidonic acid and amount of cartilage were measured and histopathological changes in the knee joint structures were observed. As results, SYT had no significant effect on the liver and kidney functions. Interleukin-$1{\beta}$(IL-$1{\beta}$), interleukin-6(IL-6), monocyte chemo attractant protein-1(MCP-1) and tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) were significantly decreased. Inflammation cytokines in joints were all significantly decreased. Prostaglandin $E_2(PGE_2)$, thromboxane $B_2(TXB_2)$ were significantly decreased. Destruction of cartilage on micro computed tomography(CT)-arthrography was meaningfully decreased. In terms of histopathology, infiltration of inflammation, proliferation of synovial membrane, subsidence of cartilage and bone due to penetration of excessive formation of synovial cell and destruction of cartilage were small. Based on all results mentioned above, Sayeok-tang(SYT) is believed to be meaningful for suppressing the progress of osteoarthritis and its treatments because of its anti-inflammatory effects and alleviation of pain with histopathological effective efficacy.

• 분석과학
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• 제33권1호
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• pp.11-22
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• 2020

When extracting semi-volatile components of herbal medicines using hot water vapor, some substances may react with water vapor or oxygen, and some volatile substances may be lost, when using an organic solvent extraction method has the disadvantage that it may contain a non-volatile material and residual organic solvent. In addition, it is inefficient to separate semi-volatile substances from herbal medicines into each single component and conduct biological activity research for each component to determine the effective ingredient, and some components may be lost in the separation process. In this study, semi-volatile substances evaporated under two pressure-reduced conditions in Chinese herbal medicines such as Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were separated by cooling with liquid nitrogen. Those were analyzed by gas chromatography-mass spectrometry (GC-MS) to identify the components, and this method may be used to study biological activities at the cellular level. The substances separated under reduced pressure, essential oil obtained by simultaneous distillation extraction (SDE) method and substances by using solid phase micro-extraction (SPME) from Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were analyzed by GC-MS. In the case of Cnidii Rhizoma and Aucklandiae Radix, there were some differences among the essential oil components obtained by SDE and those identified by low temperature capture (CT) and SPME method, these were believed to be produced by some volatiles reacting with water or oxygen at the boiling point temperature of water.