• Journal of Life Science
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• v.16 no.1
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• pp.37-43
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• 2006

Gap junction is an ion channel forming between adjacent cells. It also acts as a membrane channel like sodium or potassium channels in a single cell. The amino acid residues up to the $10^{th}$ position in the amino (N)-terminus of gap junction hemichannel affect gating polarity as well as current-voltage (I-V) relation. While wild-type Cx32 channel shows negative gating polarity and inwardly rectifying I-V relation, T8D channel in which threonine residue at $8^{th}$ position is replaced with negatively charged aspartate residue shows reverse gating polarity and linear I-V relation. It is still unclear whether these changes are resulted from the charge effect or the conformational change of the N-terminus. To clarify this issue, we made a mutant channel harboring cysteine residue at the $8^{th}$ position (T8C) and characterized its biophysical properties using substituted-cysteine accessibility method (SCAM). T8C channel shows negative gating polarity and inwardly rectifying I-V relation as wild-type channel does. This result indicates that the substitution of cysteine residue dose not perturb the original conformation of wild-type channel. To elucidate the charge effect two types of methaenthiosulfonate (MTS) reagents (negatively charged $MTSES^-$ and positively charged $MTSET^+$) were used. When $MTSES^-$ was applied, T8C channel behaved as T8D channel, showing positive gating polarity and linear I-V relation. This result indicates that the addition of a negative charge changes the biophysical properties of T8C channel. However, positively charged $MTSET^+$ maintained the main features of T8C channel as expected. It is likely that the addition of a charge by small MTS reagents does not distort the conformation of the N-terminus. Therefore, the opposite effects of $MTSES^-$ and $MTSETT^+$ on T8C channel suggest that the addition of a charge itself rather than the conformational change of the N-terminus changes gating polarity and I-V relation. Furthermore, the accessibility of MTS reagents to amino acid residues at the $8^{th}$ position supports the idea that the N-terminus of gap junction channel forms or lies in the aqueous pore.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.368-372
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• 2000

The fruit structure of 'Fuji' apples from full bloom to maturing was observed from 1997 to 1998. Cell division period of the fruit was found to be 4 to 5 weeks after full bloom. Vascular bundles in the inner part of the fruit skin which were not described in the books illustrating apple fruit structure was observed, as they were tentatively named as outer vascular bundles (OVB), and another vascular bundles were also observed newly in periphery of locules, as they were tentatively named as inner vascular bundles (IVB). In the observation of the inner epidermis (IE) in the inner part of the locules on 2 days prior to full bloom, the guard cells were observed and these were disappeared in the observation made 2 days later, i.e. on full bloom. The formation of fruit skin was observed at the microscope 65 days after full bloom and the number of cell which organized the fruit skin did not change from this time to maturation period. Tannin which is mainly in the fruit skin changing from continuously during fruit growth, specially the tannin of epidermis disappeared completely 100 days after full bloom stage, and then constituted again. Starch was not almost found out in cell division period of fruit from full bloom stage after this time it constituted much at flesh part and decreased at maturation period. Epidermis was developed by uniform cells of a layer the cell of epidermis constituted irregularity after pigmentation stage, the organization of fruit was not close because the very big intercellular space constituted at hypodermis and flesh structure.

• Korean journal of applied entomology
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• v.20 no.4 s.49
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• pp.229-233
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• 1981

This study was to investigate ornamental trees injuries at the Tobong ornamental tree farm, which is located in Uichongpu City, Kyonggido. The injury was caused by $SO_2$ gas from the smoke of the vicinal factories. The results obtained are as follows: 1 The total concentration of sulfur in leaves was increased with incerased degree of injury The most severe injuries were found at the distance between 70-120m from the western boundary of the Tobong ornamental 4ree farm with a highest concentration of total sulfur at $0.5-0.6\%$. This means the injuries caused by the acute injury and the temperature changes. 2. Significant differences were found between normal and injured portion of the same trees in Juniperus chinensis. 3. Anatomical study of the leaf tissues, showed the plasmolysis occured both in spongy and epidermal cells, leading to shrinkage and destruction. An intercellular space and stomatal periphery became wider.

• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.296-302
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• 1991

Compression wood and opposite wood formed in a branch of Taxodium distichum Rich. is described and compared in qualitative and quantitative anatomical aspects. The qualitative features of compression wood appeared to differ from those of opposite wood in very gradual tracheid transition from earlywood to latewood, roundish tracheid shape on cross surface, tracheid tip distortion on radial surface, and existence of intercellular spaces and helical cavities. In quantitative features, compression wood tracheids showed shorter lengths than opposite wood. The ray density and the number of uniseriate rays were greater in compression wood than in opposite wood but the height of uniseriate rays in compression wood was smaller than in opposite wood.

• Journal of Yeungnam Medical Science
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• v.15 no.1
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• pp.36-46
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• 1998

Solid and papillary epithelial neoplasm of pancreas is a rare tumor, usually affecting young women, and its histogenesis is still controversial. This study was performed to define the clinicopathologic features and cellular origin of this tumor. Eight female cases of solid and papillary epithelial neoplasm of pancreas were studied by analyzing the clinicopathologic findings and immunohistochemical and electron-microscopic findings. The age of eight cases ranged from 21 to 54 years (mean, 34 years). The tumors developed in the tail (4 cases), body-tail (2 cases), body (1 case) and head (1 case). The mean diameter of tumors was 9.3 em (range, 5.5 to 13 cm). Tumors showed solid, cystic and hemorrhagic areas. Histologically, the tumor cells were uniformly round or polygonal in shape, and formed solid sheets and papillary pattern. On the immunohistochemical stain, 8 cases (100%) were immunoreactive for ${\alpha}1$-antitrypsin, 7 cases (87.5%) for cytokeratin, 7 cases (87.5%) for progesterone receptor, 6 cases (75%) for vimentin, and 1 case (12.5%) for synaptophysin, respectively. None of them were immunoreactive for estrogen receptor. Electron microscopic examination showed many mitochondria, annulate lamellae and canaliculi-like gap. These findings suggest that solid and papillary epithelial tumor of pancreas possibly originates from totipotent stem cells.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.319-327
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• 1993

The objectives of this study were to isolate ectomycorrhizal fungi associated with roots of Pinus rigida ${\times}$ P. taeda trees planted in Chonbuk and Daejon locations and to identify them, and to observe the morphology of mycorrhizae formed by the isolated fungi. Pinus rigida ${\times}$ P. taeda seedlings formed ectomycorrhizae with Rhizopogon rubescens, Rhizopogon sp. and Suillus pictus isolated from the roots of mature Pinus rigida ${\times}$ P. taeda trees, Pinus rigida ${\times}$ P. taeda seedlings formed ectomycorrhizae with Pisolithus tinetorius too. The root surface of inoculated seedlings was covered with mycelia, and Hartig net were well developed in those roots. The size of vacuole was small, and the protoplasm was planty in ectomycorrhizal cell, compared to nonmycorrhizal cell. But the size of nuclei are not changed even in ectomycorrhizal cell.

• Journal of the Korean Wood Science and Technology
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• v.12 no.4
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• pp.47-52
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• 1984

본(本) 연구(硏究)는 연필향나무(Juniperus virginiana L.) 지재(技材)내에 형성(形成)된 압축이상재(壓縮異常材)(compression wood) 및 대응재(對應材)(opposite wood)에 관한 주사전자현미경적(走査電子顯微鏡的)인 특성(特性)을 비교(比較)하기 위하여 수행(遂行)되었는데 그 결과(結果)는 다음과 같다. 1. 압축이상재(壓縮異常材)의 가도관(假導管) 이행(移行)은 연륜(年輪)의 경계부(境界部)를 제외하고는 점진적(漸進的)이나 대응재(對應材)의 가도관(假導管) 이행(移行)은 급진적(急進的)이다. 그리고 대응재(對應材)에 있어서 추재율(秋材率)은 변이(變異)가 심하며 추재(秋材) 가도관(假導管)의 배열(排列)은 불균일(不均一)하다. 2. 압축이상재(壓縮異常材) 및 대응재(對應材)의 가도관(假導管)은 그 횡단면(橫斷面)의 모양(模樣)이각각 둥근형 및 모난형이다. 그리고 압축이상재(壓縮異常材)와 대응재(對應材) 모두에서는 큰 가도관(假導管)과 작은 가도관(假導管)이 혼재(混在)되어 있으나 나선상(螺旋狀)의 째짐이 가도관(假導管)의 막(膜)에 존재(存在)하지 않으며 세포간극(細胞間隙)은 경계부(境界部)를 지니는 경우가 있는데 압축이상재(壓縮異常材)에만 존재(存在) 한다. 3. 분야막공(分野膜工)에 있어서 압축이상재(壓縮異常材)의 막공구(膜孔口)는 대응재(對應材)의 것보다 가도관(假導管)측의 막공록(膜孔綠)이 더 넓기 때문에 더 좁으며 경사(傾斜)가 급한 타원형(楕圓形)을 나타낸다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.408-412
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• 2010

내화수림대 조성을 위하여 난대수종 중 내화성 수종을 선발하고자 콘칼로미터를 이용하여 5수종(감탕나무, 구실잣밤나무, 동백나무, 붉가시나무, 후박나무)을 대상으로 수피, 가지, 생엽 등 부위별 연소특성을 분석하였다. 난대수종의 평균 열방출율(HRR)은 감탕나무($167.66kW/m^2$)>구실잣밤나무($142.80kW/m^2$)>동백나무($116.78kW/m^2$)>후박나무($95.48kW/m^2$)>붉가시나무($79.80kW/m^2$) 순으로 나타났다. 따라서, 붉가시나무가 산불 발생시 다른 수종에 비해서 화재강도가 낮은 것으로 사료된다. 수종별 부위(생엽, 가지, 수피)의 착화특성을 분석한 결과, 생엽에서 최초자연발화온도는 동백나무, 감탕나무($697^{\circ}C$)>후박나무($672^{\circ}C$)>구실잣밤나무($663^{\circ}C$)>붉가시나무($658^{\circ}C$) 순으로 나타났으며, 가지에서는 구실잣나무($671^{\circ}C$)>후박나무($669^{\circ}C$)>감탕나무($661^{\circ}C$)>붉가시나무($657^{\circ}C$)>동백나무($591^{\circ}C$) 순으로 나타났으며, 수피에서 동백나무($839^{\circ}C$)>후박나무($804^{\circ}C$)>동백나무($784^{\circ}C$)>붉가시나무($780^{\circ}C$)>감탕나무($749^{\circ}C$) 순으로 나타났다. 수종별 부위에 있어서 최초자연발화온도가 다른 것은 수종에 따라 조직과 세포간극 형태에 따라 수분함량의 차이가 착화특성을 다르게 나타내는 것으로 사료된다.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.101-102
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• 2010

규화목은 목본식물의 2차목부가 화석화된 것으로 화석화 과정에서 여러 종류의 무기물이 세포를 치환하거나 세포의 내강 또는 간극에 침투하여 고화된 것이다. 이 과정에서 목재의 해부학적 구조가 잘 보존되는 경우가 많고 이를 통해 목재의 수종을 비교적 정확히 동정할 수 있을 뿐만 아니라 과거 환경에 대한 정보를 얻을 수 있다. 목재는 유관속 형성층에 의해 매년 새롭게 형성되어 축적되며 형성된 조직은 성장하는 당해 기후변화를 반영하게 된다. 따라서 화석목재를 통해 과거 기후조건을 복원할 수 있는 정보를 얻을 수 있는 경우도 많다). 본 연구는 포항 분지의 신제3기 마이오세 장기층군에서 채집한 규화목의 조직과 나이테 분석을 통해 고환경을 해석한 것이다. 장기층군에서 채집한 15개의 규화목 표본 중 나이테가 잘 나타나는 5개 표본에서 나이테를 분석하고 그중 조직이 잘 보존된 1개의 표본에 대해 목재해부학적 연구를 수행하였다. 나무가 성장함에 따라 나타나는 나이테의 폭은 환경적 요인 등으로 매년 일정하지 않다. 이런 인접연륜간의 연륜변동성을 알아보기 위해 연륜연대학(Dendrochronology)에서 널리 사용되는 평균민감도 측정 방법을 사용하였다. 평균민감도는 연륜변동이 어느 정도있느냐를 알아보는 것으로 인접한 연륜들 사이의 차이를 측정하여 인접연륜간 연륜변동성을 나타낸다. 평균민감도 값이 크면 연륜폭 변동이 크다는 것을 의미하며 나무가 자라는 당시 환경인자의 변화량이 컸다고 해석할 수 있다. 조직이 잘 보존된 1개의 표본은 목재해부학적 특징상 느릅나무과(Ulmaceae) 느릅나무속(Ulmus)으로 동정되었다. 또한 5개 표본의 나이테를 분석한 결과 평균민감도는 0.34~0.41 범위를 나타내며 전체 평균은 0.37의 값을 갖는 것으로 나타났다. 이것은 규화목 생성 당시 환경이 온대기후를 지시하며, 물 공급이 매년 계절적인 제한을 받았거나 다양한 변화가 있어 계절적으로 강수량 변화가 있었음을 지시한다.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.1-5
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• 2012

This study was conducted to elucidate the cause of micro-cracking in the exocarp of 'Jinmi' peach (Prunus persica). through the microscopic observation of fruit skin development in 4 varieties such as 'Jinmi', 'Kanoiwa Hakuto', 'Kawanakajima Hakuto', and 'Yumyeong'. Micro-cracking was noted in 59.1% of 'Jinmi', 30.6% of 'Kanoiwa Hakuto', 21.5% 'Kawanakajima Hakuto' and 6.4% of 'Yumyeong', respectively. The development of intercellular spaces, which increased rapidly with the fruit development, was easily observed at 69 days after full bloom. Histological studies revealed that the number of outer epiderm cell layers of 'Jinmi' was smaller than that of the other three cultivars, and thinner than the 'Kawanakajima Hakuto' and 'Yumyeong'. Moreover, 'Jinmi' exhibited smaller and flatter shapes in the sub-epidermal cell layer than those of the 'Kawanakajima Hakuto' and 'Yumyeong' at harvest season. Therefore, these results suggest that micro-cracking of 'Jinmi' fruit skin was due to poor-developed outer epidermis and well-developed intercellular spaces just under exocarp as compared with other varieties.