• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1165-1169
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• 2012

The fluorescence intensity of DNA-intercalated ethidium with [ethidium]/[DNA base] being 0.005 was quenched upon the binding of another intercalating ligand, meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP). Addition of $Ca^{2+}$ enhanced the quenching efficiency. The range of separations between donor and acceptor molecules, within which total quenching occurs, was calculated using a one-dimensional resonance energy transfer mechanism to be 9.5 base-pairs or $32.3{\AA}$ in the absence of $Ca^{2+}$ ions. The distance increased to 18.7 base-pairs or about $63.6{\AA}$ in the presence $100{\mu}M$ $Ca^{2+}$. Considering that (1) $Ca^{2+}$ had little effect on the binding modes of ethidium and TMPyP, which was investigated by reduced linear dichroism and (2) spectral overlap between the emission spectrum of ethidium and the absorption spectrum of TMPyP was maintained in the presence of $Ca^{2+}$, contributions from orientation factor and spectral overlap to $Ca^{2+}$-induced enhancement in DNA mediated energy transfer was limited. Although there is no direct evidence, electron transfer along the DNA stem may accompany the observed fluorescence quenching. In this respect, DNA bound $Ca^{2+}$ act as a partially conducting medium.

• 농약과학회지
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• 제6권3호
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• pp.218-223
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• 2002

[ $45^{\circ}C$ ]의 25%(v/v) dioxane-수용액(${\mu}=0.1M$) 중에서 살충제, flupyrazofos의 가수분해 반응속도상수를 자외선 분광법으로 측정하였다. 용매효과($|m|{\ll}|{\ell}|$) 및 반응 속도식($k_{obs.}=k_O+k_{H3O}+[H_3O^+]+k_{OH}-Kw/[H_3O^+]$) 그리고 생성물 분석 결과로부터 flupyrazofos는 trigonal-bipyramidal형($d^2sp^3$) 중간체를 경유하여 pH 4.0 이하의 산성 용액에서는 $A_{AC}2$형의 특정 산-촉매 반응, pH 11.0 이상의 알카리성 용액에서는 $B_{AC}2$ 형의 특정 염기-촉매 반응 그리고 PH $5.0{\sim}10.0$ 사이에서는 $B_{AC}2$형의 일반 산 및 염기-촉매반응에 따른 일련의 가수분해 반응 메카니즘을 제안하였다. 또한, 중성 용액 중에서 flupyrazofos는 매우 안정한 ($8.0{\times}10^{-8}sec^{-1}$) 화합물로 반감기는 약 3개월($45^{\circ}C$) 이상이었다.

• 생약학회지
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• 제15권2호
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• pp.108-113
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• 1984

The structure of tuguaconitine, MP $196{\sim}198^{\circ}C$, a new diterpene alkaloid isolated from the roots of Aconitum sibiricum P., was studied. Its empirical formula is $C_{23}H_{35}NO_7$ and spectroscopic evidence shows that the base contains three methoxyl, three hydroxyl and one N-ethyl groups. The acute toxicities of most of Aconitum species were strong and the acute toxicity of the alkaloid fraction of A. sibiricum was decreased by Glycyrrhizae, black bean or Zingiberis extract.

• 대한화학회지
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• 제28권1호
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• pp.20-25
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• 1984

소다아미드를 포함하는 복합염기에 의한 트란스-1,2-디할로시클로헥산으로부터의 탈할로겐화 수소반응을 연구 검토한 결과 이성질화, 중수소 동위원소 효과 및 이탈기의 원소효과 등이 모두 E2반응 메카니즘으로 반응이 진행됨을 강력히 시사하고 있다.

• Journal of Chest Surgery
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• 제30권3호
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• pp.326-329
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• 1997

관상동맥 우회수술은 일반적으로 저체온하에 인공심폐기를 사용하여 체외순환을 하면서 심정지상태에서 시행하는 것이 일반적 인 방법이다. 그러나 선택적 인 병변에 한 하여는 체 외순환을 하지 않고 정상적인 심박동 상태에서 관상동맥 우회 술을 사용하는 방법이 시도되고 있다. 저자들은 우관상동맥에 100%협착을 보이고 경미한 운동시 심한 흉통을 호소한 환자에서 체외순환 없이 관상동맥 우회 술을 성공적으로 시행하였기 에 문헌고찰과함께 보고하는 바이다.

• 한국경영과학회지
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• 제42권1호
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• pp.65-77
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• 2017

The purpose of this paper is to develop a model of level evaluation for data governance that can diagnose and verify level of insufficient part of operating data governance. We expanded the previous study related on attribute indices of data governance and developed a level model of evaluation and items. The model of level evaluation for data governance is the level of evaluation and has items of 400 components. We used previous studies and expert opinion analysis such as the Delphi technique, KJ method in this paper. This study contributes to literature by developing a level evaluation model for data governance at the early phase. This paper will be used for the base line data in objective evidence of performance in the companies and agencies of operating data governance.

• Journal of Korean Neurosurgical Society
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• 제53권3호
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• pp.180-182
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• 2013

We describe a case of intracranial carotid artery occlusion due to penetrating craniofacial injury by high velocity foreign body that was relieved by decompressive surgery. A 46-year-old man presented with a penetrating wound to his face. A piece of an electric angular grinder disc became lodged in the anterior skull base. Computed tomography revealed that the disc had penetrated the unilateral paraclinoid and suprasellar areas without flow of the intracranial carotid artery on the lesion side. The cavernous sinus was also compromised. Removal of the anterior clinoid process reopened the carotid blood flow, and the injection of glue into the cavernous sinus restored complete hemostasis during extraction of the fragment from the face. Digital subtraction angiography revealed complete recanalization of the carotid artery without any evidence of dissection. Accurate diagnosis regarding the extent of the compromised structures and urgent decompressive surgery with adequate hemostasis minimized the severity of penetrating damage in our patient.

• East Asian Economic Review
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• 제17권2호
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• pp.129-159
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• 2013

Over the course of the recent global financial crisis, emerging economies experienced massive swings in capital inflows. In this paper, we estimate a VAR model to assess the impact of capital inflow shocks, which are identified using a set of sign restrictions, on house prices in Korea. We base the analysis on three alternative measures of capital inflows: net total inflows, net portfolio inflows and gross total inflows. The results suggest that capital inflow shocks have a significantly positive and persistent effect on real house prices. Although shocks to capital inflows are found to be substantially more important for Korean asset markets than for other OECD countries, their overall explanatory power is modest. Using regional house price data we also show that capital inflow shocks have an asymmetric effect on property markets across the seven largest Korean cities and across different parts of Seoul.

• Asia pacific journal of information systems
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• 제12권4호
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• pp.139-172
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• 2002

Comtemporary firms need capability of acquiring external knowledge and internalizing it to cope with environmental fluctuation. The paper analyzes the impact of absorptive capacity, an ability to recognize and utilize external knowledge, on knowledge acquisition of the firm, and examines the role of trust in the knowledge acquisition process. Data were collected from 84 domestic companies that had adopted ERP packages. The results indicate that prior experiences of knowledge acquisition, communication mechanism, and conflict resolution mechanism affect knowledge acquisition positively. Among those independent variables, communication mechanism and conflict resolution mechanism significantly and positively related with trust. Trust is, in turn, positively associated with knowledge acquisition. Meanwhile, previous knowledge base and prior relationship with the knowledge provider do not affect knowledge acquisition. Further, the results provide evidence that trust plays a mediating role between other absorptive capacity factors and knowledge acquisition.

• 유통과학연구
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• 제12권3호
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• pp.99-103
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• 2014

Purpose - The objective of this study was to examine the volatility of the exchange rate of the Somali shilling (SoSh) during 2010, especially the exchange rate between the Somali shilling and US dollar. Research design, data, and methodology - The study employed aquantitative research design; the data was analyzed using contents analysis for the data pertaining to the exchange rate between the US dollar and Somali Shilling in 2010. Results - The main findings were that the exchange rate was very volatile during 2010 because of three sources: (1) Imbalance of demand and supply in the money market, (2) People adopting the US dollar as the medium of exchange forgoods and services, thereby reducing the circulation of the SoSh, and (3) Lack of a strong central bank. Conclusions - The study suggested three possible remedies: the establishment of an effective central bank that matches the demand and supply of the currencies, adoption of the Somali shilling as the official currency base for the prices of commodities, and minimizing the imports into the country and maximizing its exports, to support the strengthening of the Somali shilling.