Pion Photo Production in the(1232) Region

최태근 空軍士官學校 1989 論文集 Vol.26 No.-

Pion photoproduction has been studied through the bag model. Until now, others have described nucleon and ∆-particle as the spherical bag under the assumption that N and ∆ are separated by the hyperfine interaction. In the present work, we calculate M1 transition amplitude for pion photoproduction near the ∆(1232) resonance, using a version of the chiral bag model based on an effective Lagrangian that reproduces correct pion-nucleon interation through the third order in the pion field. We consider the ∆-particle as the deformed bag (prolate or oblate) associated with the gluon and pion exchange effects, while the nucleon as a spherical bag. Our results show the contribution of the deformed ∆(1232) is almost 1% for M1 transition amplitude.

염기성 pH에서 Enterobacter amnigenus GG0461의 질산이온 흡수증가

최태근,김성태,한민우,김영기 한국응용생명화학회 2008 Journal of Applied Biological Chemistry (J. Appl. Vol.51 No.1

Salt accumulation in soils of greenhouse due to the massive application of nitrogen fertilizers causes salt stress on the various crops, a serious problem in domestic agriculture. Since the majority of the salinity is nitrate, the excess nitrate should be removed; therefore, a bacterial strain having high capacity of nitrate uptake and identified as Enterobacter amnigenus GG0461 was isolated from the soils of greenhouse. Optimum conditions for the bacterial growth and nitrate uptake were investigated. GG0461 was able to grow without nitrate; however, nitrate facilitated the growth. The rate of nitrate uptake increased at alkaline pH and both growth and nitrate uptake were maximal at pH 8-9. When the initial pH of culture medium was increased to pH 8 or 9, it was decreased to neutral upon bacterial growth and nitrate uptake. These results imply that the major factor mediating bacterial nitrate uptake is a nitrate/proton antiporter. The fact was supported by the effect of nitrate addition in the absence of nitrate, since the addition of nitrate greatly increased the nitrate uptake and rapidly decreased pH of media. 질소비료의 과량 시용에 따른 시설원예지 토양 중 염류집적은 다양한 작물에 염류장애를 유발하여 국내농업에 심각한 문제가 되고 있다. 염류의 주성분은 질산염으로 필요이상의 질산 이온을 제거하기 위하여 질산이온 흡수력이 크며, Enterobacter amnigenus GG0461로 동정된 토양세균을 시설원예 토양에서 분리하였다. 이 균주의 최적 생육 및 질산이온 흡수력을 조사하였을 때, GG0461 균주는 질산이온이 없는 조건에서 생육이 가능하나, 질산이온이 존재할 때 생육이 크게 촉진되었다. 또한, 염기성 조건에서 질산이온 흡수율이 증가하였으며, 성장과 질산이온 흡수 모두 pH 8-9에서 최대로 나타났다. 배지의 초기 pH를 8과 9로 조정하였을 때, 균주에 의하여 질산이온이 흡수 됨에 따라 배지의 pH는 중성으로 감소하였다. 이러한 결과는 질산이온 흡수를 위한 주된 인자가 nitrate/proton antiporter임을 의미한다. 이것은 질산이온이 없는 조건에서 질산이온의 첨가 효과인 질산이온 흡수의 급격한 증가와 빠른 배지의 pH 감소 사실로도 확인되었다.

톨라신의 용혈활성에 대한 Ni²⁺의 저해효과

최태근,왕희성,김영기,Choi, Tae-Keun,Wang, Hee-Sung,Kim, Young-Kee 한국응용생명화학회 2009 Journal of Applied Biological Chemistry (J. Appl. Vol.52 No.1

세균독소인 톨라신은 재배버섯에서 버섯균사 및 자실체의 구조를 파괴하여 갈반병을 일으킨다. 톨라신의 세포독성은 톨라신이 적혈구의 세포막에 pore를 형성하여 세포구조를 파괴하기 때문에 용혈활성을 측정하여 평가한다. 저자들은 $Zn^{2+}$와 $Cd^{2+}$에 의한 톨라신의 용혈활성 저해효과를 측정하는 중에 $Ni^{2+}$이 또 다른 저해제로 톨라신의 독성을 억제하는 것을 발견하였다. $Ni^{2+}$에 의한 톨라신 용혈활성의 저해는 농도의존적이었으며, Ki 값은 대략 10mM이었고, 이것은 $Ni^{2+}$이 $Cd^{2+}$에 비하여 저해효과가 높음을 의미한다. 용혈활성은 50mM 이상의 $Ni^{2+}$농도에서 완전히 제거되었으며, $Ni^{2+}$의 효과는 EDTA 첨가에 의해 가역적임을 확인하였다. 톨라신에 의한 용혈활성이 20mM $Ni^{2+}$에 의해서 완전히 억제된 상태에서 EDTA를 가하면 즉각 용혈활성이 나타났다. $Ni^{2+}$에 의한 톨라신 독성의 저해기작은 알 수 없지만, $Ni^{2+}$은 톨라신의 독성과정인 막결합, 분자중합체 형성, pore 형성, pore를 통한 막대한 양의 이온이동 등에 작용할 수 있을 것이다. 된 연구의 결과는 $Ni^{2+}$이 독성과정의 마지막 단계인 pore를 통한 이온이동 과정을 저해함을 보여준다. The bacterial toxin, tolaasin, causes brown blotch disease on the cultivated mushrooms by collapsing fungal and fruiting body structure of mushroom. Cytotoxicity of tolaasin was evaluated by measuring hemolytic activity because tolaasins form membrane pores on the red blood cells and destroy cell structure. While we investigated the inhibitions of hemolytic activity of tolaasin by $Zn^{2+}$ and $Cd^{2+}$, we found that $Ni^{2+}$ is another antagonist to block the toxicity of tolaasin. $Ni^{2+}$ inhibited the tolaasin-induced hemolysis in a dose-dependent manner and its Ki value was $\sim10$ mM, implying that the inhibitory effect of $Ni^{2+}$ is stronger than that of $Cd^{2+}$. The hemolytic activity was completely inhibited by $Ni^{2+}$ at the concentration higher than 50 mM. The effect of $Ni^{2+}$ was reversible since it was removed by the addition of EDTA. When the tolaasin-induced hemolysis was suppressed by the addition of 20 mM $Ni^{2+}$, the subsequent addition of EDIA immediately initiated the hemolysis. Although the mechanism of $Ni^{2+}$ -induced inhibition on tolaasin toxicity is not known, $Ni^{2+}$ could inhibit any of fallowing processes of tolaasin action, membrane binding, molecular multimerization, pore formation, and massive ion transport through the membrane pore. Our results indicate that $Ni^{2+}$ inhibits the pore activity of tolaasin, the last step of the toxic process.

캐온 광생성에서 Λ(1405)의 연구

최태근,정문택,박명렬,유병길,장성주 한국물리학회 2007 새물리 Vol.54 No.5

We estimate the cross section for photoproduction $\gamma p\to K^+\Lambda(1405)$ within the standard pole model, which has been applied to the analysis of radiative decay widths $\Gamma_{K^- p\to \Lambda\gamma}$ and $\Gamma_{K^- p\to \Sigma^0\gamma}$. For the present calculation, we consider the nucleon resonances and vector mesons adopted in the analysis of the decay widths and use their coupling constants, including the principal coupling constants of $\Lambda(1405),$ extracted from decay data. The cross section is very sensitive to a change in the leading coupling constant $g_{Kp\Lambda_{1405}}$, showing the dominance in $\Lambda(1405)$ in photoproduction. 복사붕괴 진폭 $\Gamma_{K^- p\to \Lambda\gamma}$와 $\Gamma_{K^- p\to \Sigma^0\gamma}$의 해석에 적용된 표준 폴 모형으로 광생성 반응 $\gamma p \to K^+\Lambda(1405)$의 단면적을 계산하였다. 붕괴 진폭의 해석에 사용한 핵자 공명입자와 벡터 메존의 기여를 고려하였으며 $\Lambda(1405)$의 주요 결합상수들을 위시한 입자들의 결합상수들은 복사 붕괴에서 도출된 값들을 사용하였다. 단면적은 주요 결합상수 $g_{Kp\Lambda_{1405}}$의 변화에 매우 민감하여 광생성 반응에서 $\Lambda_{1405}$항의 기여가 지배적임을 보여준다.

Pion and Proton Form Factors in the Regge Description of Electroproduction p(e, e'π+)n

최태근,공국진,유병길 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.7

Electroproduction of + above the resonance region is analyzed in the Regge model for + exchanges. The importance of the roles of the pion and the proton form factors in the process is discussed in comparison with the existing models of Kaskulov and Mosel and of Vrancx and Ryckebusch. The present model with a proton form factor of a simple dipole-type is shown to yield a better description of DESY and JLab data over those models for the high Q2 and −t region up to 5 GeV2.

Radiative Decay of K−p System and Photoproduction of (1405)

최태근,김경식,유병길 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.5

The properties of the Λ(1405) resonance have been investigated from radiative decay of K−p → Yr and photoproduction rp → K+Λ(1405) within the framework of the isobar model. For a consistent result with recently measured branching ratios, the axial vector meson K1(1270) is taken into account. Strong and electromagnetic coupling constants of Λ(1405) are extracted from these branching ratios and are applied to the analysis of K+Λ(1405) photoproduction. The total and differential cross sections are predicted. The properties of the Λ(1405) resonance have been investigated from radiative decay of K−p → Yr and photoproduction rp → K+Λ(1405) within the framework of the isobar model. For a consistent result with recently measured branching ratios, the axial vector meson K1(1270) is taken into account. Strong and electromagnetic coupling constants of Λ(1405) are extracted from these branching ratios and are applied to the analysis of K+Λ(1405) photoproduction. The total and differential cross sections are predicted.

생태관광 개발과 환경복원 사업으로 지역의 지속가능한 발전 방안에 관한 연구 -시흥시 토취장을 중심으로-

최태근 ( Tae Keun Choi ) 관광경영학회 2013 관광경영연구 Vol.57 No.-

This study takes a look at how many citizens in South Korea have recently been having interest in various leisure themes depending on changes in the environment. In particular, the desire to want to enjoy a variety of eco-tourism is on the rise in order to improve the health and quality of life. Siheung`s borrow pit has been compromised by the development of neglect and environmental restoration projects in the region. If eco-tourism is to be developed, the satisfaction of local citizens and the creation of a regional eco-city brand are the cornerstones of a sustainable development plan. A separate survey targeting residents, government officials, and opinion leaders regarding a sustainable development plan is proposed. Looking at the analysis of empirical results, many residents hold a necessity in regards to the development of Siheung`s borrow pit. However, in order to propel the eco-tourism business, education for residents` understanding, participation, and knowledge will be carried out and specialists will be trained. It is deduced that the proceedings and direction of eco-tourism development must be presented in an integrated manner.

생화학,분자생물학 : 염기성 pH에서 Enterobacter amnigenus GG0461의 질산이온 흡수증가

최태근 ( Tae Keun Choi ),김성태 ( Sung Tae Kim ),한민우 ( Min Woo Han ),김영기 ( Young Kee Kim ) 한국응용생명화학회 2008 Applied Biological Chemistry (Appl Biol Chem) Vol.51 No.1

톨라신의 용혈활성에 대한 Ni2+의 저해효과

최태근 ( Tae Keun Choi ),왕희성 ( Hee Sung Wang ),김영기 ( Young Kee Kim ) 한국응용생명화학회 2009 Journal of Applied Biological Chemistry (J. Appl. Vol.52 No.1

Sigma and Sigma-Like Terms in Pion Weak-Production Near Threshold

천명기,최태근,김경식 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

The scalar and the pseudo-scalar (PS)form factors represent the scalar and the PS quark density distributions, respectively, on a nucleon due to finite quark mases, and they are directly related to the α term in π - N scatering and to the-like term in charged pion electro-production. We show that they manifest themselves in pion weak-productions. We also discus how to deduce and estimate the effects of such form factors in pion weak-productions.