저온처리한 오이의 자엽에서 광합성 활성의 광의존성 저해

鄭翼敎,李春煥,朴仁虎,全鉉植,文炳鎔,李鎭範 東亞大學校附設基礎科學硏究所 1993 基礎科學硏究論文集 Vol.10 No.1

저온에 노출된(4℃에서 24시간)오이 유식물에서 자엽의 산소 발생률 및 quantum yield, CO₂고정능, 실온에서 측정한 엽록소 형광유도의 변화 등을 조사하였다. 저온의 광조건에 노출된 오이 유식물에서 자엽의 최대 산소 발생률, quantum yield, CO₂고정능, variable fluorescence가 현저히 감소하였다. 특히 저온의 광조건은 엽록소 형광유도에서 Fo를 증가시키고 (Fv)m/Fm을 감소시켰는데 이는 광저해로 인하여 광계 II의 반응중심이 손상되고 광합성 활성이 감소된데서 기인한 것으로 생각된다. 또한 저온처리 동안 엽록소 형광소멸에서도 암조건보다 광조건에서 qQ가 크게 감소하였으나 qNP는 차이가 없었고, 저온처리 이후의 회복과정에서도(24시간) 암조건보다 광조건에서 엽록소 형광의 relaxation이 느리고 낮게 나타나 오이 잎의 광합성 기구가 저온의 광처리에 의해 보다 심하게 저해되었음을 알 수 있었다. 특히 stress indicator인 ??은 저온의 암조건에서 20% 감소한 반면, 광조건에서는 60%나 감소하여 오이의 광합성기구가 저온에 매우 민감하게 반응하는 것 으로 생각되었으며 이는 광합성기구에 대한 저온장해가 뚜렷하게 광의존성임을 나타낸다. The photosynthetic activities in relation to oxygen evolution rates, quantum yield, CO₂ uptake rates and room temperature chlorophyll fluorescence were investigated in cotyledons of cucumber seedlings exposed to low temperature(at 4°C) for 24 h. Light-chilling caused more inhibition on light-saturated maximum oxygen evolution rates, quantum yield, and CO₂uptake rates than dark-chilling did in the cucumber plant. Light-chilling induced more marked increase in Fo and decrease in (Fv)m/Fm than dark-chilling did in the room temperature chlorophyll induction kinetics. The above results affected by chilling in the light are considered to be associated with the partial damage of the reaction center of PS Ⅱ and the decreased photosynthetic activities. There occurred a large decrease in qQ with little change in qNP in the light-chilling plant. When light-and dark-chilled plants were recovered at room temperature for 24 h and their chlorophyll fluorescences were induced with light doubling technique, light-chilled plants showed more smaller magnitude and rate of fluorescence relaxation than dark-chilled plants. These suggest that light-chilling might cause some alterations in transthylakoid △pH formation, and that photosynthetic apparatus of cucumber cotyledons is more susceptible to light-chilling In the fast fluorescence induction kinetics ?? was decreased by 60% in the light-chilled plants with reference to 25°C light-grown plants, while the dark-chilled plants showed a decreased rate of only 20% with reference to 25°C dark-treated plants for 24h, indicating that cucumber seedling is very sensitive to chilling stress. So, it is certain that chilling injury to the photosynthetic apparatus is strongly dependent on the presence of light in cucumber seedlings.

보리 유식물에 처리한 수은의 분포 및 독성 연구

이춘환,이진범,장호식,문병용,정익교,전현식,이진애 동의대학교 기초과학연구소 1993 基礎科學硏究論文集 Vol.3 No.1

The inhibitory effects of mercury ions on the growth of barley seedlings were studied and the distribution of metal elements in the organs of treated plants was investigated by using synchrotron radiation induced X-ray emission (SRIXE). Although the treatment of mercury ions caused growth inhibition, the mercury-specific increase in variable fluorescence and the abolishment of energy-dependent quenching in broken barley chloroplasts as shown by Moon et al.(1992) were not observed in the leaves of growth-inhibited seedlings. Instead the treatment of mercury decreased Fmax and Fo values. However, Fmax/Fo ratio and photochemical and nonphotochemical quenching coefficients were not affected significantly. By SRIXE analysis of 10μM mercury chloride treated seedlings, accumulation of mercury in roots was observed after 1 hour of treatment and similar concentration was sustained for 48 hours. Relative contents of mercury was high in roots and underground nodes where seeds were attached, but was very low in leaves. Iron and zinc were also distributed mainly in the lower parts of the seedlings. However after 72 hours of treatment the contents of these metals in roots decreased and their distribution became more uniform, which may lead to death of the plants. These results suggest that the observed inhibitory effects on barley seedlings upto 48 hours after the treatment is not due to direct damages in the photosynthetic apparatus, but due to its accumulation in roots and the consequent retardation of the growth of barley seedlings. The decrease in Fmax and Fo is probably due to the decrease in chlorophyll and protein contents caused by the retardation of growth. The observed slow expansion of primary leaves could be also explained by the retardation of growth, but the fluorescence induction pattern from the leaves did not show characteristic symptoms of leaves under water stress.

편도선 절제술 중 Epinephrine 국소침윤에 의한 심정지와 급성 폐부종 1예

안익순,최준석,박천희,이철승,김원태,임경준 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.3

Hemostasis and a clear surgical field are obtained by the local infiltration of a local anesthetic mixed with epinephrine during tonsillectomy. However, epinephrine may in itself, due to its cardiovascular effect, cause arrhythmia, heart failure, Pulmonary edema, and even cardiac arrest. We describe a 22-year-old patient who developed cardiac arrest due to epinephrine infiltration during tonsillectomy. The patient was resuscitated and recovered without any sequele after intensive treatment.

Voxel머리팬텀 제작 및 붕소중성자포획요법 선량계산에의 응용

이춘식,이춘익,이재기 대한방사선 방어학회 2001 방사선방어학회지 Vol.26 No.2

해부학적으로 단순한 수학적인형팬텀의 한계를 극복하기 위한 voxel머리팬텀을 제작하고 BNCT(Boron Neutron Capture Therapy) 시행 시 선량분포를 계산하였다. 일반목적 몬테칼로 코드인 MCNP4B의 반복구조 알고리즘을 이용하여 voxel몬테칼로 계산체계를 수립하였고 두 가지 물질로 구성된 예시적 voxel팬텀과 기하체조합팬텀의 계산값 비교를 통해 계산체계를 검증하였다. 미국 NLM(National Library of Medicine)에서 제공하는 VHP man 인체단층사진에 대한 분할 및 색인작업을 통해 voxel머리팬텀을 제작하여 AP 및 PA 방향에서 입사하는 넓고 평행한 광자 및 중성자빔에 대한 선량값을 MIRD팬텀의 계산값과 비교한 결과 중성자빔 AP방향조사 시 MIRD팬텀에서는 볼 수 없는 안구로 인한 중성자 감쇠현상을 확인할 수 있었다. 3차원 정밀계산이 필요한 BNCT 시술시 선량분포계산을 위해 뇌 중앙에 직경 5cm의 구형 뇌종양 체적을 정의하고 뇌와 종양의 붕소 함량을 조정하여 10keV 및 40keV 상부입사 중성자에 의한 장기별 흡수선량을 계산한 결과 종양에 30㎍/g, 정상세포에 3㎍/g 의 붕소를 주입한 경우 붕소함량이 없을 때에 비해 2배 가량 큰 선량을 보였다. 본 연구를 통해 voxel몬테칼로기법을 이용한 선량평가체계를 수립하였고 정밀한 선량계산을 필요로 하는 치료방사선분야 선량계산에 실제 인체에 가까운 voxel팬텀의 응용가능성을 제시하였다. Voxel head phantom for overcoming the limitation of mathematical phantom in depicting anatomical details was constructed and example dose calculation for BNCT was performed. The repeated structure algorithm of the general purpose Monte Carlo code, MCNP4B was applied for voxel Monte Carlo calculation. Simple binary voxel phantom and combinatorial geometry phantom composed of two materials were constructed for validating the voxel Monte Carlo calculation system. The tomographic images of VHP man provided by NLM(National Library of Medicine) were segmented and indexed to construct voxel head phantom. Comparison of doses for broad parallel gamma and neutron beams in AP and PA directions showed decrease of brain dose due to the attenuation of neutron in eye balls in case of voxel head phantom. The spherical tumor volume with diameter, 5cm was defined in the center of brain for BNCT dose calculation for downward neutron beam of 10keV and 40keV, the tumor dose is about doubled when boron concentration ratio between the tumor to the normal tissue is 30㎍/g to 3㎍/g. This study established the voxel Monte Carlo calculation system and suggested the feasibility of precise dose calculation in therapeutic radiology.

염화 벤질 및 벤조일에 대한 분자궤도론적 고찰

이익춘 東亞大學校 1972 東亞論叢 Vol.9 No.-

염화벤질과 염화벤조일에 대하여 확장 Huckel 분자궤도법으로 전자구조를 계산하였으며 그 결과로 부터 친핵반응성을 논의하였다. 이와 같은 고립분자모형의 반응성 계산에서는 용매효과, 입체효과등을 고려할 수가 없으므로 이론적인 반응성 예측에 많은 제한이 있음을 강조하였다. Electronic configuration of benzylchloride and benzoyl chloride have been investigated M. O.-theoretically using the extended Huckel's theory (E.H.T.), and the results were discussed in terms of nucleophilic reactivities. It has been pointed out the considerable limitation to estimate theoretically the reactivities of such molecules as described above, because of the calculation for the reactivities were not able to take account of the solvent effect and steric influence etc.

구멍갈파래 엽상체의 a 형광유도과정의 특성과 수은의 영향

김미경,강수경,이춘환,이진범,정익교 동의대학교 기초과학연구소 1995 基礎科學硏究論文集 Vol.5 No.1

The effects of mercury on the photosynthetic machinery of Ulva pertusa Kjellman were examined by measuring oxygen evolution, pigment contents, and fluorescence induction process. By increasing the concentration of added HgCl₂upto 0.6 ppm, oxygen evolution rate and pigment contents were decreased gradually. Chlorophyll α/b ratio was also decreased, suggesting that chlorophyll α was decreased (probable degraded) more rapidly than chlorophyll b by the treatment of mercury. Overall pattern of the fluorescence induction curve was very similar to that measured from terrestrial plant leaves. However, several characteristic differences observed: (1) fluorescence intensity decreased very rapidly after P(peak), (2) D(dip)-P increase was significantly reduced when measured 30 sec after a saturation pulse, and (3) Fmax was decreased when measured again 30 sec after a first measurement by using a saturation pulse. Due to the second and third characteristics, at least 30 min dark interval was required before starting an additional measurement using a sample. When the mercury concentration was increased, Fp (fluorescence intensity at P) was decreased gradually, but Fi(the intensity at inflection) did not increased. The decrease in Fp could be explained by the inhibition of mercury at a site near oxygen evolving complex. By the addition of 0.2 ppm HgCl₂, Fp was increased slightly without significant changes in ID pattern. This result suggests that the inhibition site of mercury at the electron transport chain on the reducing side of PSⅡ is not the Q_B or DCMU binding site. When the mercury concentration was increased, Fo was decreased slightly, but Fmax, (Fv)m/Fmax, qQ and qN was decreased significantly. By the addition of mercury more than 0.6 ppm, photosynthetic activities was almost completely blocked but pigment contents was stayed the same.

레이저 경화면의 형상특징 해석을 위한 프랙탈 차원의 적용

옥철호,조연상,배춘익,박흥식,전태옥 동아대학교 생산기술연구소 2000 生産技術硏究所硏究論文集 Vol.5 No.2

The determination of surface topography is believed to be extremely important in the areas of contact mechanics, adhesion and friction. In order to describe topography of various frictional surface, the harding test was carried out under different experimental conditions in dry friction. And fractal descriptors was applied to frictional surface of laser modified steel with image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimension can be determined by sum of intensity difference of surface pixel. Topography of frictional surface can be effectively obtained by fractal dimensions.

저온처리한 오이의 자엽에서 광합성 활성의 광의존성 저해

全鉉植,文炳鎔,李春煥,鄭翼敎,朴仁虎,李鎭範 동의대학교 기초과학연구소 1994 基礎科學硏究論文集 Vol.4 No.1

The photosynthetic activities in relation to oxygen evolution rates, quantum yield, CO₂uptake rates and room temperature chlorophyll fluorescence was investigated in cotyledons of cucumber seedlings exposed to low temperature(at 4℃) for 24 h. Light-chilling caused more inhibition on light-saturated maximum oxygen evolution rates, quantum yield, and CO₂uptake rates than dark-chilling did in the cucumber plant. Light-chilling induced more marked increase in Fo and decrease in (Fv)m/Fm than dark-chilling did in the room temperature chlorophyll induction kinetics. The above results affected by chilling in the light are considered to be associated with the partial damage of the reaction center of PS Ⅱ and the decreased photosynthetic activities. There occurred a large decrease in qQ with little change in qNP in the light-chilling plant. When light- and dark-chilled plants were recovered at room temperature for 24 h and their chlorophyll fluorescences were induced with light doubling technique, light-chilled plants showed more smaller magnitude and rate of fluorescence relaxation than dark-chilled plants. These suggest that light-chilling might cause some alterations in transthylakoid △pH formation, and that photosynthetic apparatus of cucumber cotyledons in more susceptible to light-chilling. In the fast fluorescence induction kinetics, F_R was decreased by 60% in the light-chilled plants with reference to 25℃ light-grown plants, while the dark-chilled plants showed a decreased rate of only 20% with reference to 25℃ dark-treated plants for 24h, indicating that cucumber seedling is very sensitive to chilling stress. So, it is certain that chilling injury to the photosynthetic apparatus is strongly dependent on the presence of light in cucumber seedlings.

The Importance of One-Eletron Effects in Conformation and Protonation of Acetamides $^*$

Ik-Choon Lee,Geoun-Bae Rhyu Korean Chemical Society 1980 Bulletin of the Korean Chemical Society Vol.1 No.1

The CNDO/2 method was used to compute relative stabilities of various configurations and conformations of acetamide, N-methylacetamide and diacetamide and their protonated forms. It was found that: (a) nonbonded interactions play important roles in determining structural preferences of the compounds, (b)$n-{\sigma}^{\ast}$ "throughbond" interactions always favor cis-protonation (relative to C-N).

MO Studies of Configurations and Conformations (IX). Molecular Structure of Sulfamoyl Chlorides

Ik-choon Lee,Byung-Choon Lee Korean Chemical Society 1980 Bulletin of the Korean Chemical Society Vol.1 No.2

Semi-empirical MO calculations were performed to investigate stereochemical properties of sulfamoyl chlorides; $R_2NSO_2Cl$ Where R = H or $CH_3$. It was found that for all the molecules considered the most preferred conformation was the form in which $n_N-{\sigma}^*_{SIC}$ conjugative interaction is a maximum and the least favored conformation was the form in which steric repulsion is large due to eclipsing of Cl and R. In case of the molecule with no symmetry i.e., $CH_2NHSO_2Cl$, the stability was also dependent upon nonbonded interactions between the eclipsing groups.