• Elastomers and Composites
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• 제46권3호
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• pp.204-210
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• 2011

본 연구에서는 황마/폴리프로필렌 강화 섬유 복합재료를 사출성형 방법으로 제조하였으며, 섬유와 열가소성 기지재의 친화력과 접착력을 향상시키기 위해 말레산 무수물(Maleic anhydride, MA)을 결합제로 사용하였다. 천연 섬유인 황마의 표면처리 관찰을 위해서 주사전자현미경(SEM)과 적외선분광기(FTIR)를 사용하였고, 인장 및 굽힘 특성을 확인하기 위하여 기계적 특성 시험을 수행하였으며, 수분흡수율도 측정하여 비교하였다. 인장 및 굽힘 시험 결과 황마 복합재료(JFRP)는 기지재로 사용된 폴리프로필렌(PP)보다 높은 강도와 탄성계수를 나타내었고, 황마 복합재료의 강도 및 탄성계수는 결합제의 비율을 1~3%까지 증가시킴에 따라 높은 결과를 보였다. 이는 결합제의 비율을 증가시킬수록 섬유와 기지재 사이의 계면접착력을 향상시킬 수 있음을 의미한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권6호
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• pp.499-508
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• 2007

Background and Purpose: Some subtypes of malignant salivary gland tumors such as adenoid cystic carcinoma (ACC) frequently result in distant metastasis of vascular origin, which are main causes of treatment failure. The reasons for the affinity for vascular metastatic potential are unclear. Therefore, molecular characteristics that influence the dissemination of metastatic tumor cells are important for the design of more effective treatment of salivary ACC. Tumor angiogenesis has been known to be essential for the distant metastasis of malignant cells. So, we determined expressions of vascular metastasis related factors in orthotopic (parotid) murine models of parotid ACC and compared with those in ectopic (subcutis) tumors of athymic mice. Experimental Design: Using specimens from murine parotid (orthotopic, experimental group) and subcutaneous (ectopic, control group) tumors, which have developed via transplantation of tumor cells, originated from human parotid ACC, we performed immunohistochemical assays with anti-vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF, FGF2), matrix metalloproteinase (MMP)-9, and interleukin (IL)-8 antibodies. We also performed immunohistochemical assays with VEGF receptor (VEGFR)-1, VEGFR-2, VEGFR-3, and phosphorylated VEGFR-2. Results: Transplantation of human ACC tumor cell $(5{\times}10^5)$ into the parotid and subcutis successfully resulted in orthotopic (parotid) and ectopic (subcutaneous) tumors in athymic mice. Immunohistochemical staining demonstrated higher expression of major angiogenic factors (VEGF, bFGF, MMP-9) in the orthotopic tumors than in ectopic tumors (P<0.05). But the expression level of angiogenic receptors were same in orthotopic and ectopic tumors of parotid ACC. Conclusion: VEGF, bFGF, and MMP-9 could be a good candidates for antiangiogenic therapy for the contol of vascular metastatic lesions of salivary ACC.

• Corrosion Science and Technology
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• 제9권6호
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• pp.259-264
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• 2010

In continuous hot dip galvanizing process, oxide formation on steel surface has an influence on Zn wetting. High strength automotive steel contains high amount of Si and Mn, where Si-Mn composite oxides such as $Mn_2SiO_4$ or $MnSiO_3$ covers the surface after annealing. Zn wetting depends on how the aluminothermia reaction can reduce the Mn-Si composite oxides and then form inhibition layer such as $Fe_2Al_5$ on the steel surface. The outward diffusion of metallic ions such as $Mn^{2+}$, $Si^{2+}$ in the steel matrix is very important factor for the formation of the surface oxides on the steel surface. The surface state and grain boundaries provide an important role for the diffusion and the surface oxide reactions. Some elements such as P, Sb, and B have a strong affinity for the interface precipitation, and it influence the diffusivity of metallic ions on grain boundaries. B oxide forms very rapildly on the steel surface during the annealing, and this promote complex oxides with $SiO_2$ or MnO. P has inter-reacted with other elements on the grain boundaries and influence the diffusion through on them. Small addition of Sb could suppress the decarburization from steel surface and retards the formation of internal and external selective oxides on the steel surface. Interface control by the trace elements such as Sb could be available to improve the Zn wettability during the hot dip galvanizing.

• KSBB Journal
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• 제16권2호
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• pp.146-152
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• 2001

rhGH-GST 융합단백질을 사용하여 재조합 대장균 세포 파쇄액으로부터 직접적으로 내포체의 solid-phase 재접힘을 수행할 수 있는 새로운 공정을 개발하였다. 그것은 고체 업자를 제거하는 동시에 초기에 목적딴백질을 흡착 포집할 수 있 는 expanded bed adsorption 크로마토그래피의 장점을 이용한 것이다. 세포 파쇄액 내 용해훤 내포체로부터의 풀린 융합단백질은 expanded bed adsorption 원리에 의해 STREAMLINE DEAE resin에 흡착되고 세포 찌꺼기 등 고체 입자물들은 위 방향 흐름에 의해 효과적으로 제거된다. Urea를 접차적으로 제거함으로써 융합단백질은 고체 matrix 표면에서 재접힘 된 후 염 놓도 구배에 의해 용출된다. 이 새로운 EBA-mediat$\xi$d 재접힘 방법은 응집현상을 획기적으로 줄이고 공정수율윤 향상시킬 뿐 아나라 공정단계 수를 줄일 수 있다. 이 공정은 우리가 알고 있는 한 세계에서 최초로 개발된 공정이며, 현재 single-chain polypeptide, affinity-tagged protein 등과 갈은 다른 행태의 단백질에 EBA를 사용한 재접힘 공정올 적용시키가 위한 연구가 진행되고 있다.

• 한국항공우주학회지
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• 제37권3호
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• pp.255-266
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• 2009

본 연구에서는 기존 설계요구도 정립과정에서 고려할 수 없었던 설계자의 주관적인 판단의 배제 및 사용자 요구도의 변화, 시스템의 생산 및 운용환경에서 발생하는 오차 등을 개념 설계과정에서 고려하는 설계 프로세스를 개발하였다. 사용자 요구도를 의사결정 모델 및 시스템 엔지니어링 기법을 사용하여 구체화하여 대안형상들을 도출하고 그 가운데에서 우수한 대안형상을 선정한다. 선정된 대안형상들에 대해 최적설계 기법을 적용한 개념설계 결과를 도출하고 여기에 강건최적설계 기법을 적용하여 사용자의 요구를 만족하면서 오차에 영향을 적게 받는 결과를 도출하도록 하였다. 본 논문에서는 최근 각광받고 있는 Very Light Jet 항공기에 대하여 개발된 프로세스를 적용해 보았다.

• Applied Biological Chemistry
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• 제35권5호
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• pp.410-414
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• 1992

Streptomyces sp. S56 endoinulase를 DEAE-cellulose에 고정화하였고 고정화 효소의 일반 특성을 유리효소와 비교하였으며 돼지감자 추출물 및 inulin의 고정화 효소에 의한 가수분해 조건을 조사하였다. 고정화 효소의 최적 작용 pH는 $4.5{\sim}5.5$로 유리효소보다 효소작용 pH가 산성으로 이동되었으며 작용 안정 pH는 6으로 유리효소와 동일하나 전반적으로 고정화에 의하여 pH 안정성은 저하되었다. 반면 온도 안정성은 고정화에 의하여 크게 증가되어 $50^{\circ}C$, 1시간 처리에서도 70%, 이상의 활성을 가지고 있었으며 또한 최적온도도 유리효소보다 높게 나타났다. 기질친화성은 고정화에 의하여 5배 정도 낮아지나 반응 최고속도는 반대로 2배 이상 증가되었다. 돼지감자 추출물 및 inulin은 고정화 효소에 의하여 48시간 내에 각각 총당의 63%, 78%를 가수분해, fructose 및 inulobiose를 주로 생산하였다.

• 한국키틴키토산학회지
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• 제23권4호
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• pp.256-261
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• 2018

Recently, the number of cardiovascular disease-related deaths worldwide has increased. Therefore, the importance of percutaneous cardiovascular intervention and drug-eluting stents (DES) has been highlighted. Despite the great clinical success of DES, the re-endothelialization at the site of stent implantation is retarded owing to the anti-proliferative effect from the coated drug, resulting in late thrombosis or very late restenosis. In order to solve this problem, studies have been actively carried out to excavate new drugs that promote rapid re-endothelialization. In this study, we introduced hydrophilic drug, tauroursodeoxycholate (TUDCA), that improves the proliferation of endothelial progenitor cells and promotes apoptosis of vascular smooth muscle cells. In addition, we utilized shellac, which is a natural resin from lac bug to coat TUDCA on the surface of the metal. When using conventional coating method including biodegradable polymers and organic solvents, phase separation between polymer and drug occurred in the coating layer that caused incomplete incorporation of drug into the polymer layer. However, when using shellac as a coating polymer, no phase separation was observed and drug was fully covered with the polymer matrix. In addition, by adjusting the composition of coating solution and modifying the hydrophilicity of the metal surface using oxygen plasma, the surface roughness decreased due to the increased affinity between coating solution and metal surface. This result provides a method of depositing a hydrophilic drug layer on the stent.

• 방사선산업학회지
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• 제9권4호
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• pp.187-192
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• 2015

CD44 is a particular adhesion molecule and facilitates both cell-cell and cell-matrix interactions. In particular, splice variants of CD44 are particularly overexpressed in a large number of malignancies and carcinomas. In this study, the $^{177}Lu$-labelled CD44 targeting antibody was prepared and bioevaluated in vitro and in vivo. Anti-CD44 was immunoconjugated with the equivalent molar ratio of cysteine-based DTPA-NCS and radioimmunoconjugated with $^{177}Lu$ at room temperature within 15 minutes. The stability was tested in human serum. An in vitro study was carried out in HT-29 human colon cancer cell lines. For the biodistribution study $^{177}Lu$-labelled anti-CD44 was injected in xenograft mice. Anti-CD44 was immunoconjugated with cysteine-based DTPA-NCS and purified by a centricon filter system having a molecular cut-off of 50 kDa. Radioimmunoconjugation with $^{177}Lu$ was reacted for 15 min at room temperature. The radiolabeling yield was >99%, and it was stable in human serum without any fragmentation or degradation. The radioimmunoconjugate showed a high binding affinity on HT-29 colon cancer cell surfaces. In a biodistribution study, the tumor-to-blood ratio of the radioimmunoconjugate was 43 : 1 at 1 day post injection (p.i) in human colon cancer bearing mice. The anti-CD44 monoclonal antibody for the targeting of colon cancer was effectively radioimmunoconjugated with $^{177}Lu$. The in vitro high immunoactivity of this radioimmunoconjugate was determined by a cell binding assay. In addition, the antibody's tumor targeting ability was demonstrated with very high uptake in tumors. This radioimmunoconjugate is applicable to therapy in human colon cancer with highly expressed CD44.

• 동의생리병리학회지
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• 제33권2호
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• pp.116-122
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• 2019

The aim of this study is to evaluate the anti-inflammatory effect of Hataedock treatment using Coptidis Rhizome and Glycyrrhiza Uralensis (CG) mixed extract in allergic rhinitis induced NC/Nga mice. We divided NC/Nga mice into 3 groups as follows; allergic rhinitis-induced group after CG Hataedock treatment (CGT, n=10), no treatment group (Ctrl), allergic rhinitis elicited group (ARE). To induce allergic rhinitis, NC/Nga mice of 3 weeks age were sensitized on 7, 8 and 9week by Ovalbumin (OVA) antigen in intranasal space. Hataedock using CG extract was administered on week 3 in allergic rhinitis-induced group (CGT) after Hataedock treatment. To identify distribution of Interlukin (IL)-4, Cluster of differentiation 40 (CD40), high-affinity IgE receptor ($Fc{\varepsilon}RI$), substance P, Matrix metallopeptidase 9 (MMP-9), Nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) p65, Inducible nitric oxide synthase (iNOS) and Cycloxygenase-2 (COX-2), we used histological examination. CGT significantly inhibited IL-4 and CD40 response compared with ARE. The reduction of Th2 cytokine expression decreased inflammatory mediators such as $Fc{\varepsilon}RI$, substance P, MMP-9, $NF-{\kappa}B$ p65, iNOS and COX-2. Such immunological improvement induced reduction of respiratory epithelial damage and mucin secretion in goblet cell. These results indicate that Hataedock treatment suppresses allergic rhinitis through modulating of Th2 responses and diminishing various inflammatory mediators in nasal mucosal tissue. It might have potential applications for prevention and treatment of allergic rhinitis.

• 멤브레인
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• 제33권5호
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• pp.240-247
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• 2023

가스 분리 방법 중에서도, 멤브레인을 이용한 CO₂ 포집 및 분리는 지속적으로 개발되고 있는 꾸준히 성장하는 분야이다. 이온성 액체(IL) 기반 복합 막은 CO₂를 분리하는 데 있어 우수한 성능값을 보여준다. 유사하게, 다양한 공중합체/IL 복합막 또한 향상된 성능을 보여준다. 이러한 공중합체/IL 복합만에 산화그래핀과 같은 필러를 첨가하면 IL과 유기 필러 사이에서 발생하는 강한 상호작용으로 인해 필러의 효과가 더욱 향상되며, 이는 결과적으로 CO₂의 친화도, 선택도 및 흡착과 같은 요소를 향상시킨다. 금속-유기 구조체(MOF)를 사용하는 공중합체/IL 복합 막은 향상된 CO₂ 투과도를 보여주었다. 이 총설에서는 이온성 액체와 공중합체복합막의 다양한 조합에 따른 이산화탄소분리성능에 대한 상관관계를 논의한다.