• Journal of Plant Biology
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• v.34 no.4
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• pp.317-323
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• 1991

Partial recovery in auxin transport capacity from inhibition by N-naphthylphthalamic acid (NPA) was observed when corn coleoptile segments were subjected to a prolonged NPA treatment. Kinetic data indicated that the recovery time is a function of the concentration of NPA applied. Desensitization to NPA was also seen in tissue slices where NPA increased net uptake of auxin, indicating that the apparant adaptation in the auxin transport system did not results possibly from auxin accumulated during transport inhibition. Studies on in vitro binding of NPA to membrane vesicles isolated from the coleoptile indicated that preincubation of the tissue with NPA resulted in the reduced binding activity. Scatchard analysis of the data indicated that this was due to decreases in the number of NPA binding sites. The possibility of causal relationship of modified NPA receptors to the sensory adaptation in auxin transport observed in coleoptile segments will be discussed.

• Journal of Life Science
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• v.30 no.1
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• pp.26-31
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• 2020

Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes significant losses to the aquaculture industry in many coastal countries. The development of a fast and sensitive detection method is therefore required to facilitate the appropriate warning of harmful algal blooms. In this study, a nuclease protection integrated with sandwich hybridization (NPA-SH) assay was developed to both qualitatively and quantitatively detect H. akashiwo. The NPA, capture and signal probes were designed by nucleotide sequencing of H. akashiwo. The applicability of NPA-SH was evaluated using cultured H. akashiwo cells and field samples collected at Goseong Bay, Korea. The results show that this method has good applicability and effectiveness in analyzing cultured cells and field samples. A linear regression equation for the quantitative analysis of H. akashiwo was obtained, and the lower detection limit of the assay was 1×10⁴ cells/ml. There was no statistically significant difference in the results of H. akashiwo quantitation using NPA-SH compared to those obtained using a microscope. These results indicate that NPA-SH can be a good alternative to the traditional microscopic method used to monitor H. akashiwo.

• Journal of Plant Biology
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• v.36 no.1
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• pp.59-66
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• 1993

In maize coleoptile segments where auxin transport capacity decreases with time following excision, susceptability of the tissue to transport inhibitors such as N-1-naphthylphthalamic acid (NPA), 3,4,5-triiodobenzoic acid (TIBA) or high concentrations of IAA was found to be rather increased. A time-dependent increase in the sensitivity to NPA can be postulated since the dose-response curve for NPA was shifted in the‘aged’tissue to the left (i.e. lower concentration). Preincubation of the tissue at a low temperature abolished the time-dependent sensitivity change, suggesting that cellular metabolism could be involved. The NPA-sensitive state was also brought about by calcium depletion of the tissue, which can be partially reversed by addition of calcium. Presence of exogenous IAA in the preincubation medium kept the auxin transport system from decay, implicating auxin as an endogenous controlling factor. Results of our experiments indicate a reversible, time-dependent changes of auxin transport system in which transport capacity and sensitivity to NPA are tightly coupled. Changes in the sensitivity to NPA were also seen in auxin action as well.

• Journal of Plant Biology
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• v.38 no.4
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• pp.343-348
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• 1995

Treatment of Pisum sativum tissue with the protein kinase inhibitor staurosphorine resulted in impairment of 3H-indoleacetic acid transport in etiolated stem segments. The transport inhibitiion was accompanied by an increase in net uptake of labeled auxin in the tissue. The magnitude of auxin accumulation in tissue treated with the phytotropin N-1-naphthylphthalaic acid (NPA) which specifically blocks the efflux of auxin in the plasma membrane was reduced by the protein kinase inhibitor, suggesting that inhibition of protein phosphorylation could lead to hindrance of the auxin-exporting function of NPA receptors. The flavonoid genistein which is also known to inhibit protein kinase likewise reduced NPA-induced auxin accumulation. However, the flavonoid did not bring about auxin accumulation by itself, nor did it inhibit auxin transport. In view of the finding that the flavonoid also competes with NPA for a common binding site, a mechanism for the flavonoid effect on the NPA action will be proposed.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.203-212
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• 2008

Currently the problem that cannot attempt convenience anger to inner user and people has been stated in a National Police Agency(NPA) informatization system administered Executed an inquiry regarding users inner the our country NPA after analyzing Hint point a foreign NPA IT informatization organization decreasing by and analyzed improvement Point to measures regarding this problem at these papers, and derived from an efficient strategic plan for NPA informatization integration. As set up informatization vision of NPA and a goal, To utilize so that design a model integrated inforrnatization for advanced a business assistance system of the NPA where these results are objective for the people enhancement, and keep connection with other organization in its mind, and can accomplish a quality elevation of NPA information business. and expect as present improvement plan for efficiency of NPA information business.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.286-292
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• 1995

국내 최초의 한국표준원전 가압경수로인 울진 3,4 호기의 운전 특성을 정확하게 실시간으로 모사할 수 있는 한국표준원전 NPA가 개발되고 있다. 동 NPA는 발전소의 정상 및 비정상 운전 상태를 Desk-top 소령 컴퓨터에서 모사하여 그 결과를 그림화면(mimic)에 나타내고 운전원 조치 사항을 Interactive하게 수용할 수 있는 능력을 갖추고 있다. 한국표준원전 NPA의 개발을 위하여 울진 3,4 호기 한국표준원전의 설계 자료를 기준으로 그래픽사용자 인터레이스의 새로운 mimic 및 해석모델에서 사용하는 데이타베이스를 성공적으로 작성하였다. 향후 한국표준원전 NPA는 새로운 모형 개발을 완료한 후 발전소 운전자료와의 비교분석을 통해 성능 검증을 거치면 교육을 및 엔지니어링 작업에 유용하게 사용될 수 있을 것이다.

• The Journal of Society for e-Business Studies
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• v.6 no.2
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• pp.13-24
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• 2001

The Real-Time Best-Estimate simulator NPA4K is being developed for providing an efficient nuclear power, KALIMER, simulation environment for transient safety analyses using information visualization. The advanced features of NPA4K simulator are the Once-Through Running Environment, Functionalities of displaying the several X-Y Plot on one system, and Multi-thread Processing, The objective of NPA4K simulator is ta realize the Virtual Reality Environment through Network and Internet technology in Nuclear Power Plants.

• Korean Journal of Microbiology
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• v.13 no.2
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• pp.51-58
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• 1975

Mutagenic action of p-phenylenediamine(PA) and nitro-p-phenylenediamine(NPA) has been investigated using auxotroph mutants of S.typhimurium LT-2 strain. PA, the major component of hair day in South and East Asia and South America, was proved as potent frams-shift mutagen only after activation system. On the contrary, NAP was directly mutagenic in this system.

• Proceedings of the Korea Society for Simulation Conference
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• 2004.05a
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• pp.89-93
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• 2004

본 MMI를 통해 개발된 웨스팅하우스 950 Mwe 최적 NPA는 기존의 단순한 Point Kinetics 모델이 아닌 정교한 3D 실시간 노심모델과 RETRAN 코드를 기반으로 하는 실시간 NSSS 열수력 모델(ARTS)이 통합된 모델을 갖추었으며, 해당형식 발전소(Westinghouse 3 Loop PWR Plant)의 여러 가지 과도사고를 실시간으로 정상, 비정상, 비상운전 모의할 수 있도록 개발되었다. 이 NPA는 기존의 유닉스 환경이 아닌 일반 범용 PC 서버와 윈도우즈 환경(Operating System)이라는 개방형 서버-클라이언트 구조를 채택하여 저렴하고 실용적인 시스템을 추구하였다. 다양한 색상 표현이 가능한 GUI 툴을 이용하여 노심 내부의 3D 열중성자 속 분포등 사용자가 직관적으로 알 수 있는 쉬운 구성의 클라이언트 제어 시스템을 개발, 연계하여 사용자의 편의성을 도모하였다.

• Journal of Plant Biology
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• v.36 no.1
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• pp.67-74
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• 1993

Both polar and gravity-induced lateral transport of auxin was markedly reduced in corn coleoptile segments by octanol treatment. Octanol enhance net auxin uptake without affecting that of benzoic acid, suggesting that the effect did not result from a nonspecific action on general membrane permeability. Since naphthylphthalamic acid (NPA) action on both transport and net uptake of auxin was substantially decreased in the presence of octanol, a specific interaction of octanol with the NPA site (efflux carrier) can be postulated. Studies on in vitro binding of NPA to membrane vesicles indicated that octanol did not interfere with NPA binding. When basipetal transport of auxin was impared by plasmolysis, octanol still inhibited auxin transport in the plasmolyzed tissues. The results ruled out the possibility of octanol acting at the plasmodesmata. Kinetic analysis of growth indicated that IAA-sustained growth was rapidly blocked by octanol implicating a common system by which auxin transport is linked to auxin action. Possible mechanisms for octanol action will be discussed.