• 제목/요약/키워드: co-initiated

검색결과 160건 처리시간 0.028초

열잠재성 촉매에 의한 에폭시/폴리우레탄 블랜드계의 경화거동, 유변학적 및 기계적 물성에 관한 연구 (Studies on Cure Behaviors and Rheological and Mechanical Properties of Epoxy/Polyurethane Blend System initiated by Latent Thermal Catalyst)

  • 강준길;권수한;박수진
    • 대한화학회지
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    • 제46권3호
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    • pp.233-240
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    • 2002
  • 본 연구에서는 잠재성 양이온 개시제 (N-benzyl pyrazinium hexafluoroantiminate, BPH)를 이용한 에폭시/폴리우레탄 블랜드계의 혼합조성에 따른 경화거동과 유변학적 특성 그리고 기계적 물성 변화에 대하여 연구하였다. 블랜드계의 반응성은 DSC를 이용하여 반응 온도에 따른 전환률을 구하여 측정하였으며, 유변학적 특성은 레오미터를 이용한 등온 실험을 통하여 측정하였고, 가교 활성화에너지(Ec)는 겔화 시간과 경화 온도를 이용하여 Arrhenius 방정식으로 구하였다. 한편, 경화된 시편의 기계적 물성은 충격강도 실험을 통하여 측정하였다. 실험결과, 블랜드계의 열잠재성 촉매로 사용된 BPH는 어떤 공개시제 없이도 우수한 촉매 특성을 나타내었다. 본 블랜드계의 가교 활성화에너지 및 충격강도는 PU가 30 wt% 첨가되었을 때 최대를 나타내었는데, 이는 EP와 PU간의 수소결합으로 인한 치밀한 가교밀도의 증가 때문이라고 사료된다.

Introgression of Sex-Limited Larval Markings to a Productive Multivoltine Strain of Silkworm Bombyx mori L.

  • Rao, D. Raghavendra;Singh Ravindra;Basavaraja H.K.;Kariappa B.K.;Dandin S.B.;Rufaie S.Z. Haque
    • International Journal of Industrial Entomology and Biomaterials
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    • 제13권1호
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    • pp.7-14
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    • 2006
  • A breeding programme was initiated during 2001 to introduce sex-limited larval markings to a productive multivoltine breed - BL67 from an inbred sex-limited line, MY1 (SL) maintained at Central Sericultural Research and Training Institute, Mysore. Introgressive hybridization, recurrent backcrossing for six generations followed by sib-mating resulted in synthesis of a new multivoltine silkworm breed BL67 (SL) with sex-limited larval markings. The new breed was studied for combining ability by crossing with eight bivoltine breeds viz., $NB_4D_2,\;CSR_2,\;CSR_2 (SL),\;CSR_2,\;CSR_4,\;CSR_8,\;CSR_{18}\;and\;CSR_{19}$. General combining ability effects of the new breed showed its superiority over the popular Pure Mysore by expressing significant GCA effects for six out of twelve characters whereas the results are on par with the original multivoltine breed. The hybrid $BL67(SL){\times}CSR2(SL)$ excelled in several quantitative characters such as pupation rate (90.2%), cocoon weight (1.97 g), cocoon shell weight (40 cg), cocoon shell ratio (20.3%), filament length (918 m), denier (2.96), raw silk percentage (14.96%) and neatness (90 p). Studies on cocoon size variability revealed that the cocoons of $BL67(SL){\times}CSR2(SL)$ were found comparatively uniform showing less standard deviation of 6.55 and co-efficient of variation of 3.91 %. The suitability of newly developed breed for easy grain age operation and commercial exploitation with promising hybrid have been discussed.

오령산 단일 투여를 통한 일차성 고혈압 치험례 (Treatment of Primary Hypertension by Oryung-san Monotherapy: a Case Report)

  • 장인수;김민지;한현진;정민정;강세영
    • 대한한방내과학회지
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    • 제35권1호
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    • pp.106-110
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    • 2014
  • Objectives : To report a case of the treatment of primary hypertension by Oryung-san (五苓散: Wulingsan in Chinese, Goreisan in Japanese) monotherapy. Methods : The blood pressure (BP) fluctuation was checked of a woman who had sudden BP elevation without a history of hypertension treatment. There were no specific history of disease and results for the laboratory examination and image diagnosis including MRI. The woman was diagnosed with primary hypertension and she was given supple of Oryung-san extract (Hanpoong Pharm Co.) 3 g, three times a day for three months. The BP has been checked with digital sphygmomanometer (HEM-7111, Omron Japan) in brachial artery at home. Results and Conclusions : The patient had had stable BP since three weeks after Oryung-san treatment was initiated. There were no subjective symptoms, then Oryung-san medication also had quit after three months treatments. This shows some possibility to control hypertension using Oryung-san, which resembles thiazide that acts on the distal convoluted tubule and inhibit sodium-chloride reabsorption. For further evaluation of the effectiveness, well-designed randomized controlled trials should be undertaken.

정보통신산업에 있어서 대학의 연구전략-영향요인-성과에 관한 연구: ITRC사업 중심으로 (A Study of R&D Strategy-Environmental Factors-Performances of the Academia in the Information and Telecommunication Industry: An Analysis of ITRC Projects)

  • 이영덕
    • 기술혁신학회지
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    • 제11권4호
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    • pp.431-449
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    • 2008
  • 본 연구는 정보통신 연구개발사업인 ITRC사업을 대상으로 대학연구개발의 동기, 전략, 및 성과간의 관계를 분석을 하였다. 이를 위하여 기존연구를 기반으로 '동기-전략, 환경요인-전략, 및 환경요인-성과 간의 관계'에 관한 연구모형을 설정하였으며, 아울러 설문조사에서 얻어진 데이터를 활용한 통계분석을 통하여 가설을 검증하였다. 가설검증 결과에 대한 종합적인 판단을 통하여 대학에서의 연구개발전략 수립 및 수행에 관련된 정책적인 제언을 하고자 하였으며, 아울러 실제 대학 연구개발성과의 활용도 및 기여도 제고를 위한 정책적 제언도 병행하였다.

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Cell to Cell Interaction Can Activate Membrane-bound APRIL Which Are Expressed on Inflammatory Macrophages

  • Lee, Sang-Min;Kim, Won-Jung;Suk, Kyoung-Ho;Lee, Won-Ha
    • IMMUNE NETWORK
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    • 제10권5호
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    • pp.173-180
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    • 2010
  • Background: APRIL, originally known as a cytokine involved in B cell survival, is now known to regulate the inflammatory activation of macrophages. Although the signal initiated from APRIL has been demonstrated, its role in cellular activation is still not clear due to the presence of BAFF, a closely related member of TNF superfamily, which share same receptors (TACI and BCMA) with APRIL. Methods: Through transfection of siRNA, BAFF-deficient THP-1 cells (human macrophage-like cells) were generated and APRIL-mediated inflammatory activities were tested. The expression patterns of APRIL were also tested in vivo. Results: BAFF-deficient THP-1 cells responded to APRIL-stimulating agents such as monoclonal antibody against APRIL and soluble form of TACI or BCMA. Furthermore, co-incubation of the siBAFF-deficient THP-1 cells with a human B cell line (Ramos) resulted in an activation of THP-1 cells which was dependent on interactions between APRIL and TACI/BCMA. Immunohistochemical analysis of human pathologic samples detected the expression of both APRIL and TACI in macrophage-rich areas. Additionally, human macrophage primary culture expressed APRIL on the cell surface. Conclusion: These observations indicate that APRIL, which is expressed on macrophages in pathologic tissues with chronic inflammation, may mediate activation signals through its interaction with its counterparts via cell-to-cell interaction.

2-비닐피리딘계 이온교환수지의 합성과 그의 이온교환능 (Synthesis and Ion Exchange Capacity of 2-Vinylpyridine Series Ion Exchange Resins)

  • 김동원;송해영
    • 대한화학회지
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    • 제25권3호
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    • pp.160-165
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    • 1981
  • 2-비닐피리딘계의 세가지 종류의 고분자물질을 합성하여 그들의 구조를 적외선 흡수 스펙트럼으로 확인한 결과, 2-비닐피리딘-디비닐벤젠의 삼중합체임을 알 수 있었다. 또한 2-비닐피리딘-아세트산비닐-디비닐벤젠의 삼중합체는 $98{\circ}C$에서 50분간 반응시킬 때 가장좋은 수율을 나타냈다. 특히 합성된 삼중합체중, 2-비닐피리딘-비닐알코올-디비닐벤젠과, 2-비닐피리딘-인산비닐-디비닐벤젠은 2-비닐피리딘-아세트산비닐-디비닐벤젠보다 큰 이온교환용량을 가지며, 2-비닐피리딘-비닐알코올-디비닐벤젠과 2-비닐피리딘-인산비닐-디비닐벤젠의 이온교환용량은 각각, 3.69 meq/g 및 5.38 meq/g이었다. 마지막으로 Mg(Ⅱ), Co(Ⅱ) 및 Cd(Ⅱ)금속이온에 대한 흡착능을 알아보았다.

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금속산화물(Cu-ferrite)를 이용한 수소제조 연구 (Study on the hydrogen production using the metal oxide (Cu-ferrite))

  • 박주식;서인태;김정민;이상호;황갑진
    • 한국수소및신에너지학회논문집
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    • 제15권3호
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    • pp.201-207
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    • 2004
  • Redox characteristics of metal oxide for hydrogen production by thermochemical water-splitting were investigated. $CuFe_2O_4$ as a redox pair that had a different molar ratio of Cu and Fe were prepared by co-precipitation method. Hydrogen production consisted of water-splitting step and thermal reduction step was performed below 1200K. Redox characteristics of Cu-ferrites were studied using the thermal gravimetric analysis technique. Also, structure change of Cu-ferrite during thermal reduction was investigated using the high temperature controlled XRD. In results, oxygen release of Cu-ferrite during the thermal reduction was initiated at oxygen site combined with Cu. Consequently, oxygen release amount of Cu-ferrite was increased with increase of Cu molar ratio of Cu-ferrite. It was found that thermal reduction of Cu-ferrite was begun at $875^\circ{C}$. It was confirmed that structure of Cu-ferrite was changed to metal and cation excess metal oxide during the thermal reduction step.

Binary Vector System을 이용한 당근 (Daucus carota) 세포의 형질전환 (Transformation of Carrot (Daucus carota) Cells Using Binary Vector System)

  • 양덕조;이성택
    • KSBB Journal
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    • 제5권3호
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    • pp.247-253
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    • 1990
  • 고등식물의 형질전환용 유전자운반체로써 가장 많이 사용되고 있는 Ti-plasmid를 이용해서 당근세포를 형질 전환시키기 위한 연구의 일환으로 Agrobacterium spp를 helper로 이용하여 NPT II gene를 함유하고 있는 binary vector GA472를 당근세포에 삽입시켜 kanamycin에 대해 저항성을 나타내는 세포주를 선발하고자 본 연구를 수행하였다. 국내 토양에서 선발한 A.tumefaciens 2종과 disarmes된 PC2760 그리고 hypervirulent균주인 A281에 tri-parental mating 방법에 의해서 binary vector인 pGA472을 도입하여 transconjungants인 A. tumefaciens c-23-1/pGA472,K29-1/pGA472, PC2760/PGA472 그리고 A281/pGA472를 획득하였다. Transconjungants는 plasmid의 분리, 정제방법에 의해서 추출한 후 0.7% agarose gel 상에서 관찰해 본 결과 4균주 공히 NTPII gene이 삽입된 pGA472와 Ti-plasmid를 함유하고 있는 것을 확인 하였다. 확인된 conjugant와 당근정상조직을 동시배양방법에 의해서 형질전환을 유도한 후 정상조직은 전혀 생존이 되지않은 kanamycin에 대해서 저항을 나타내는 callus를 선발할 수 있었다.

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도심지 노면하부 지반함몰 및 공동탐사 사례 연구 (Study on Subsurface Collapse of Road Surface and Cavity Search in Urban Area)

  • 채휘영
    • 터널과지하공간
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    • 제27권6호
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    • pp.387-392
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    • 2017
  • 최근 도심지 도로 하부 지반함몰 사고는 상수관로, 하수관거, 통신관로, 가스관로, 배전지중관로, 지하철 등의 다양한 공익시설 및 지하구조물이 시공되고 있으며 이러한 시설물의 부적절한 시공, 노후로 인한 시설물 손상, 유지관리 소홀이 그 원인으로 추정되고 있다. 도로함몰은 도로하부에서 매설관 파손 등의 원인으로 공동이 발생한 후 공동이 성장 확대되어 포장면 하부까지 도달하고 도로를 통행하는 차량의 하중을 도로포장 부분이 지탱할 수 없을 정도의 소성변형이 발생하여 갑자기 함몰이 발생할 경우 인명피해 및 교통장애를 초래하는 등 사회전반적인 안전과 경제 발전에 위협이 될 수 있다. 서울시에서는 도로 하부의 공동이 함몰되기 이전 단계에서 3D GPR 탐사를 통해 발견하여 복구함으로써 지반함몰에 따른 피해를 사전에 차단하는 노력이 우선적으로 진행되고 있으며 그 사례를 소개하였다.

Gambogic Acid Disrupts Toll-like Receptor4 Activation by Blocking Lipopolysaccharides Binding to Myeloid Differentiation Factor 2

  • Lee, Jin Young;Lee, Byung Ho;Lee, Joo Young
    • Toxicological Research
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    • 제31권1호
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    • pp.11-16
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    • 2015
  • Our body's immune system has defense mechanisms against pathogens such as viruses and bacteria. Immune responses are primarily initiated by the activation of toll-like receptors (TLRs). In particular, TLR4 is well-characterized and is known to be activated by gram-negative bacteria and tissue damage signals. TLR4 requires myeloid differentiation factor 2 (MD2) as a co-receptor to recognize its ligand, lipopolysaccharides (LPS), which is an extracellular membrane component of gram-negative bacteria. Gambogic acid is a xanthonoid isolated from brownish or orange resin extracted from Garcinia hanburyi. Its primary effect is tumor suppression. Since inflammatory responses are related to the development of cancer, we hypothesized that gambogic acid may regulate TLR4 activation. Our results demonstrated that gambogic acid decreased the expression of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6, IL-12, and $IL-1{\beta}$) in both mRNA and protein levels in bone marrow-derived primary macrophages after stimulation with LPS. Gambogic acid did not inhibit the activation of Interferon regulatory factor 3 (IRF3) induced by TBK1 overexpression in a luciferase reporter gene assay using IFN-${\beta}$-PRD III-I-luc. An in vitro kinase assay using recombinant TBK1 revealed that gambogic acid did not directly inhibit TBK1 kinase activity, and instead suppressed the binding of LPS to MD2, as determined by an in vitro binding assay and confocal microscopy analysis. Together, our results demonstrate that gambogic acid disrupts LPS interaction with the TLR4/MD2 complex, the novel mechanism by which it suppresses TLR4 activation.