• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2253-2260
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• 2007

A series of tetra donor substituted [2.2]paracyclophane-based two-photon absorption (TPA) fluorophores were synthesized in neutral and cationic forms. The imaging activity of overall set of fluorophores was studied by the two-photon induced fluorescence (TPIF) method in a range of solvents. We also measured a clear progression toward a longer photoluminescence lifetime with increasing solvent polarity (intrinsic photoluminescence lifetime, τi: ~2 ns in toluene → 12-16 ns in water). The paracyclophane fluorophores with this unique property can be utilized as an optical polarity probe for the biomolecular substrates. The combined measurement of the two-photon fluorescence microscopy (TPM) cell image and TPIF lifetime can give us a better understanding of the biological processes and local environments in the cells.

• International Journal of Oral Biology
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• 제37권1호
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• pp.37-41
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• 2012

Pancreatic acinar cells exhibit a polarity that is characterized by the localization of secretory granules at the apical membrane. However, the factors that regulate cellular polarity in these cells are not well understood. In this study, we investigated the effect of Mist1, a basic helix-loop-helix transcription factor, on the cellular architecture of pancreatic acinar cells. Mist1-null mice displayed secretory granules that were diffuse throughout the pancreatic acinar cells, from the apical to basolateral membranes, whereas Mist1 heterozygote mice showed apical localization of secretory granules. Deletion of the Mist1 gene decreased the expression of type 3 inositol 1,4,5-triphosphate receptors ($IP_3R$) but did not affect apical localization and expression of $IP_3R2$. Mist1-null mice also displayed an increase in luminal areas and an increase in the expression of zymogen granules in pancreatic acinar cells. These results suggest that Mist1 plays a critical role in polar localization of cellular organelles and in maintaining cellular architecture in mouse pancreatic acinar cells.

• 식물분류학회지
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• 제37권4호
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• pp.351-361
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• 2007

In angiosperms, leaves typically develop as three-dimensional structure with dorsoventral, longitudinal, and lateral axes. We have shown that the control of two axes of leaves, longitudinal and lateral axis, can be genetically separable, and four classes of genes are responsible for the polar cell expansion and polar cell proliferation in Arabidopsis. In monocots, unifacial leaf, in which leaf surface consists only of abaxial identity, has been evolved in a number of divergent species. The unifacial leaves provide very unique opportunities for the developmental studies of the leaf axes formation in monocots, because their leaf polarities are highly disorganized. In addition, the mechanism of the parallel evolution of such drastic changes in leaf polarities is of interest from an evolutionary viewpoint. In this article, we describe our recent approaches to reveal the mechanism of unifacial leaf development and evolution, including recent advances in the leaf polarity specification in angiosperms.

• 한국통신학회논문지
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• 제30권9C호
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• pp.860-870
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• 2005

본 논문에서는 karnaugh map(k-map)상의 셀을 이용하여 $2^{n}$개의 서로 다른 극수(polarity)를 갖는 GRM(Generalized Reed-Muller)상수를 생성하는 새로운 기법을 제안하였다. n개의 입력변수에 대한 일반적인 GRM 함수의 생성 방법은 단일 변수에 대한 변환 행렬을 구하고 이를 n번의 Kronecker 곱을 행한 변환 행렬을 이용하여 GRM 상수를 구하는 것이다. 이런 방법을 사용하는 경우, 변수의 숫자가 증가함에 따라 변환 행렬의 차수가 $2^{n}\times2^{n}$로 커지는 단점을 갖는다. 이에 반하여 본 논문에서는 k-map상에서 변수를 축약시킨 셀 [$f_{i}$]을 구하고 이를 단일 변수 변환 행렬과 연산하여 GBM 상수를 구하는 새로운 기법을 제안한다. 본 논문에서 제안한 새로운 방법과 타 논문과의 비교를 한 결과, 기존 방법은 가산기, 승산기, KP(Kronecker 곱 승산기)회로가 필요한데 반하여 본 논문에서는 가산기만이 필요하므로 효율적인 VLSI 설계에 유리하다

• Journal of Ginseng Research
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• 제44권2호
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• pp.321-331
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• 2020

Background: The patatin-related phospholipase AIII family (pPLAIIIs) genes alter cell elongation and cell wall composition in Arabidopsis and rice plant, suggesting diverse commercial purposes of the economically important medicinal ginseng plant. Herein, we show the functional characterization of a ginseng pPLAIII gene for the first time and discuss its potential applications. Methods: pPLAIIIs were identified from ginseng expressed sequence tag clones and further confirmed by search against ginseng database and polymerase chain reaction. A clone showing the highest homology with pPLAIIIβ was shown to be overexpressed in Arabidopsis using Agrobacterium. Quantitative polymerase chain reaction was performed to analyze ginseng pPLAIIIβ expression. Phenotypes were observed using a low-vacuum scanning electron microscope. Lignin was stained using phloroglucinol and quantified using acetyl bromide. Results: The PgpPLAIIIβ transcripts were observed in all organs of 2-year-old ginseng. Overexpression of ginseng pPLAIIIβ (PgpPLAIIIβ-OE) in Arabidopsis resulted in small and stunted plants. It shortened the trichomes and decreased trichome number, indicating defects in cell polarity. Furthermore, OE lines exhibited enlarged seeds with less number per silique. The YUCCA9 gene was downregulated in the OE lines, which is reported to be associated with lignification. Accordingly, lignin was stained less in the OE lines, and the expression of two transcription factors related to lignin biosynthesis was also decreased significantly. Conclusion: Overexpression of pPLAIIIβ retarded cell elongation in all the tested organs except seeds, which were longer and thicker than those of the controls. Shorter root length is related to auxinresponsive genes, and its stunted phenotype showed decreased lignin content.

• 생명과학회지
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• 제26권3호
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• pp.282-288
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• 2016

단백질-단백질 결합은 수용체 단백질, 효소, 세포 골격 단백질의 세포내 위치 결정 및 기능 조절에 중요한 역할을 한다. Postsynaptic density-95/disks large/zonula occludens-1 (PDZ) 도메인을 가진 단백질들은 시냅스 가소성, 신경세포 성장과 분화뿐만 아니라 많은 질병의 병태생리에 중요하게 관여하는 scaffold 단백질로 작용한다. Multi-PDZ domain protein 1 (MUPP1)은 13개 PDZ 도메인을 가지는 단백질로서 세포막 수용체 군집화, 신호전달 복합체 구성, 세포 골격 조정에 대한 매개 역할을 하는 것으로 알려지고 있지만 MUPP1의 세포 내 기능은 아직 명확히 밝혀지지 않았다. 본 연구에서 MUPP1의 아미노 말단 PDZ 도메인과 결합하는 새로운 단백질을 규명하기 위하여 효모 two-hybrid 방법을 이용하였고 Wdpcp (전에 Fritz로 알려짐)이 MUPP1과 결합하는 것을 확인하였다. Wdpcp는 planar cell polarity (PCP) effector로서 세포 이동과 섬모형성에 관여하는 것으로 알려져 있다. Wdpcp는 MUPP1의 첫 번째 PDZ 도메인과 결합하지만, 다른 PDZ 도메인과는 결합하지 않았다. 또한 MUPP1와 Wdpcp의 결합에서 Wdpcp의 C-말단부위가 결합에 필수적임을 효모 two-hybrid 방법으로 확인하였다. 이러한 단백질간 결합은 glutathione S-transferase (GST) pull-down assay, 공동면역침강, HEK-293T 세포에서의 발현위치를 통하여 추가적으로 확인하였다. 이러한 결과들은, MUPP1과 Wdpcp 결합은 세포내 액틴 다이내믹스(dynamics)와 세포이동 조절에 역할을 할 가능성을 시사한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권4호
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• pp.281-288
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• 2001

Anticancer effect of methanol extract of Caesalpinia sappan L. on oral carcinoma (KB) and osteosarcoma (HOS) cells were investigated in this study. In order to elucidate the anticancer mechanism of Caesalpinia sappan L, we analyzed telomerase inhibitory effect of the methanol extract of Caesalpinia sappan L. In addition we prepared 5 fraction samples according to its polarity differences and analyzed anticancer effects on oral carcinoma and osteosarcoma cells. Following results are obtained in this study. 1. 50% cell proliferation inhibitory value ($IC_{50}$) of the methanol extract of Caesalpinia sappan L. against oral carcinoma (KB) cells and osteosarcoma (HOS) cells were $9.0{\mu}g/ml$ and $10.9{\mu}g/ml$, respectively. 2. The methanol extract of Caesalpinia sappan L. showed inhibitory effect of telomerase which is required for cancer cell immortality. Therefore, it seems that the anticancer effect of methanol extract of Caesalpinia sappan is at least partially due to telomerase inhibitory effect. 3. Five fraction samples were prepared according to its polarity and 88.7% of ingredient of total methanol extract was transferred to ethylacetate fraction. Thin layer chromatography analysis showed that dichloromethane fraction contained ingredient with relatively high polarity and ethylacetate fraction contained similar ingredient found in total methanol extract. 4. Anticancer effect was observed in n-hexane, dichloromethane, and ethylacetate fractions. The highest anticancer effect was found in dichloromethane fraction which had $IC_{50}$ value of 4.4 and $>4.0{\mu}g/ml$ against oral carcinoma (KB) cells and osteosarcoma (HOS) cells, respectively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.583-590
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• 2007

Anticancer effect of methanol extract of Caesalpinia sappan L. on oral carcinoma(KB) and osteosarcoma(HOS) cells were investigated in this study. In order to elucidate the anticancer mechanism of Caesalpinia sappan L, we analyzed telomerase inhibitory effect of the methanol extract of Caesalpinia sappan L. In addition, we prepared 5 fraction samples according to its polarity differences and analyzed anticancer effects on oral carcinoma and osteosarcoma cells. Following results are obtained in this study. 1. 50% cell proliferation inhibitory value($IC_{50}$) of the methanol extract of Caesalpinia sappan L. against oral carcinoma(KB) cells and osteosarco ma(HOS) cells were $9.0{\mu}g/ml\;and\;10.9{\mu}g/ml$, respectively. 2. The methanol extract of Caesalpinia sappan L. showed inhibitory effect of telomerase which is required for cancer cell immortality. Therefore, it seems that the anticancer effect of methanol extract of Caesalpinia sappan is at least partially due to telomerase inhibitory effect. 3. Five fraction samples were prepared according to its polarity and 88.7% of ingredient of total methanol extract was transferred to ethylacetate fraction. Thin layer chromatography analysis showed that dichloromethane fraction contained ingredient with relatively high polarity and ethylacetate fraction contained similar ingredient found in total methanol extract. 4. Anticancer effect was observed in n-hexane, dichloromethane, and ethylacetate fractions. The highest anticancer effect was found in dichloromethane fraction which had $IC_{50}$ value of $4.4{\mu}g/ml$ and > $4.0{\mu}g/ml$ against oral carcinoma(KB) cells and osteosarcoma(HOS) cells, respectively.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.652-653
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• 2014

본 논문에서는 카르노 맵상에서 생성된 Cell [fi]을 이용하여 GRM 상수를 생성하는 방법에 대해 논의하였다. Cell을 이용한 방법은 GRM 상수를 구하는 일반적인 방법과는 다르게 카르노 맵상에서 임의의 Cell들을 선택하여 그 Cell들을 단일변수 변환행렬과 연산해서 다시 카르노 맵으로 mapping하는 방법이다. 또한 이 방법을 극수의 순환성에 적용하여 새로운 GRM 상수 생성 방법에 대해 논의하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.194-195
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• 2013

This paper presents novel single-phase PWM AC-AC converters that can solve commutation problem in single-phase direct AC-AC converter without sensing input voltage polarity. By using the basic switching cell concept and coupled inductor, the proposed converter can be short and open-circuit without damping switching devices. A 120 W prototype is built and tested to verify performance of the proposed converter.